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PRIORITY
[0001] This application is a continuation of U.S. patent application Ser. No. 14/330,125, filed on Jul. 14, 2014, which is a continuation of U.S. patent application Ser. No. 14/176,829, filed on Feb. 10, 2014, now U.S. Pat. No. 8,777,786, which claims the benefit of priority based on U.S. Provisional Application Ser. No. 61/843,712 filed on Jul. 8, 2013, and all of the foregoing applications are hereby incorporated by reference herein in their entirety.
FIELD
[0002] The present invention relates to arrow systems, and more particularly, to a lighted nock that can be deactivated to save battery power and prevent accidental activation in the field.
BACKGROUND
[0003] The use of lighted nocks for bow hunting is known. Lighted nocks are beneficial because they allow the hunter to track prey shot with an arrow, particularly in low-light conditions. However conventional lighted nocks are inconvenient to use.
[0004] Lighted nocks are typically lighted with a light emitting diode (LED) powered by a small battery, typically lithium-type. The nock is either clear or translucent so that the LED light source can light up the nock when the battery power is applied. Typically the act of inserting the battery/LED lights up the nock. The act of inserting the battery requires that the nock assembly be removed from the arrow shaft. Then the assembly must be re-installed once the nock is lit. The nock must be removed again to turn the light off.
[0005] The need to repeatedly remove the nock in the field is awkward, inconvenient and might lead to a missed shot opportunity. Also, the repeated removal and insertion of the nock can damage the arrow shaft and/or nock assembly over time. It is not desirable to pre-light the nocks prior to hunting because of battery life concerns and because of the potential that the lit nocks will spook prey if the lights are seen. Therefore, there is a need to provide an improved lighted nock system.
SUMMARY
[0006] The present disclosure teaches various example embodiments that address certain disadvantages in the prior art. A lighted nock system, apparatus and method are disclosed. An activation collar is provided to a nock to permit activation/de-activation of the LED light source without the need to remove the nock from the arrow shaft. A nock adaptor can be provided to a nock housing end portion to provide a range of outside diameters to the shaft-mating end of the nock. The nock adaptors thus permit the lighted nock system to fit a range of arrow shaft sizes (inside diameters). The lighted nock and a plurality of adaptor sizes can be provided together in a single package or kit that will fit most standard carbon and aluminum arrow shafts. A method of operating the lighted nock system and device is also disclosed.
[0007] According to certain example embodiments, a lighted nock device includes a nock body, the nock activation collar, a nock housing and LED/battery assembly. The nock body includes a first plurality of radially arrayed teeth and a plurality of gaps defined between the teeth. The nock activation collar is disposed adjacent the first plurality of teeth. The collar includes a second plurality of radially arrayed teeth projecting longitudinally outwards towards the first plurality of teeth. The second plurality of teeth are configured to interleave with the first plurality of teeth in a first rotational position when the second plurality of teeth are rotationally aligned with the gaps between the first plurality of teeth. The second plurality of teeth are configured to abut the first plurality of teeth in a second rotational position when the second plurality of teeth are rotationally aligned with the first plurality of teeth.
[0008] According to another example embodiment, a lighted nock kit for arrow shafts comprises a package. In the package are disposed a lighted nock, and first and second adaptors. The lighted nock assembly includes a shaft insertion portion having a first diameter dimension. The first adaptor includes an internal opening having an internal diameter conforming to the first diameter dimension of the shaft insertion portion of the lighted nock assembly. The first adaptor has a first adaptor outside diameter larger than the first end outside diameter dimension of the shaft insertion portion of the lighted nock assembly. The second adaptor includes an internal opening having an internal diameter conforming to the first diameter dimension of the shaft insertion portion of the lighted nock assembly. The second adaptor has a second adaptor outside diameter larger than the first adaptor outside diameter.
[0009] In a further example embodiment, a method of operating a lighted nock includes placing the lighted nock in a deactivated mode by rotating a nock activation collar with respect to a nock body until a plurality of teeth defined in the nock body are abutting and aligned with a plurality of teeth defined in the nock activation collar, thereby preventing the nock body from moving longitudinally inward towards a nock housing to close a light activation gap in response to pressure applied to a distal end of the nock body. The lighted nock is placed in a ready to fire mode by rotating the nock activation collar with respect to a nock body until the plurality of teeth defined in the nock body are offset from the plurality of teeth defined in the nock activation collar such that the plurality of teeth defined in the nock activation collar are aligned with gaps defined between the plurality of teeth defined in the nock body. The lighted nock is placed in a lit mode by pressing on the distal end of nock body when the lighted nock is in the ready to fire mode with a sufficient force to close the activation gap between the nock body and the nock housing. The lighted nock is returned to the ready to fire mode by moving the nock body distally away from the nock housing to open up the activation gap. All of the foregoing steps can be performed while the lighted nock remains inserted into the end of an arrow shaft.
[0010] The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. It is understood that the features mentioned hereinbefore and those to be commented on hereinafter may be used not only in the specified combinations, but also in other combinations or in isolation, without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an exploded perspective view of a lighted nock system for an arrow shaft according to an example embodiment of the present invention.
[0012] FIG. 2 is a front view of a packaged lighted nock system kit for arrow shafts according to an example embodiment of the present invention.
[0013] FIG. 3 is an assembly perspective view of a lighted nock system for arrow shafts according to an example embodiment of the present invention.
[0014] FIG. 4 is a perspective view of an LED and battery assembly for a lighted nock system according to an example embodiment of the present invention.
[0015] FIG. 5 is a side view of an LED and battery assembly for a lighted nock system according to an example embodiment of the present invention.
[0016] FIG. 6 is a perspective view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0017] FIG. 7 is a rear view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0018] FIG. 8 is a front view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0019] FIG. 9 is a bottom view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0020] FIG. 10 is a top view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0021] FIG. 11 is another perspective view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0022] FIG. 12 is a side view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0023] FIG. 13 is another side view of a universal nock for a lighted nock system according to an example embodiment of the present invention.
[0024] FIG. 14 is a perspective view of a nock activation collar for a lighted nock system according to an example embodiment of the present invention.
[0025] FIG. 15 is a rear view of a nock activation collar for a lighted nock system according to an example embodiment of the present invention.
[0026] FIG. 16 is a front view of a nock activation collar for a lighted nock system according to an example embodiment of the present invention.
[0027] FIG. 17 is a side view of a nock activation collar for a lighted nock system according to an example embodiment of the present invention.
[0028] FIG. 18 is a perspective view of a nock housing for a lighted nock system according to an example embodiment of the present invention.
[0029] FIG. 19 is a side view of a nock housing for a lighted nock system according to an example embodiment of the present invention.
[0030] FIG. 20 is a top view of a nock housing for a lighted nock system according to an example embodiment of the present invention.
[0031] FIG. 21 is a cross-section side view of a nock housing for a lighted nock system according to an example embodiment of the present invention taken along line a-a of FIG. 20 .
[0032] FIG. 22 is a cross-section end view of a nock housing for a lighted nock system according to an example embodiment of the present invention taken along line b-b of FIG. 20 .
[0033] FIG. 23 is a perspective view of a battery retention screw for a lighted nock system according to an example embodiment of the present invention.
[0034] FIG. 24 is a side view of a battery retention screw for a lighted nock system according to an example embodiment of the present invention.
[0035] FIG. 25 is a perspective view of a lighted nock system for arrow shafts in a deactivated mode according to an example embodiment of the present invention.
[0036] FIG. 26 is a perspective view of a lighted nock system for arrow shafts in a ready to fire mode according to an example embodiment of the present invention.
[0037] FIG. 27 is a perspective view of a lighted nock system for arrow shafts in a activated mode according to an example embodiment of the present invention.
[0038] FIG. 28 is a side view of a lighted nock system for arrow shafts in a deactivated mode according to an example embodiment of the present invention.
[0039] FIG. 29 is a side view of a lighted nock system for arrow shafts in a lighted or ready-to-fire mode according to an example embodiment of the present invention.
[0040] FIG. 30 is a side view of a lighted nock system for arrow shafts in a activated mode according to an example embodiment of the present invention.
[0041] FIG. 31 is a perspective view of a shaft adapter for a lighted nock system for arrow shafts according to an example embodiment of the present invention.
[0042] FIG. 32 is a longitudinal cross section side view of a shaft adapter for a lighted nock system for arrow shafts according to an example embodiment of the present invention.
DETAILED DESCRIPTION
[0043] In the following description, the present invention will be explained with reference to example embodiments thereof. However, these example embodiments are not intended to limit the present invention to any specific environment, applications or particular implementations described in these example embodiments. Therefore, description of these example embodiments is only for purpose of illustration rather than limitation. It should be appreciated that, in the following example embodiments and the attached drawings, elements unrelated to the present invention are omitted from depiction; and dimensional relationships among individual elements in the attached drawings are illustrated only for ease of understanding, but not to limit the actual scale.
[0044] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular example embodiments described. On the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
[0045] Referring to FIG. 1 , the lighted nock assembly 100 is shown in axial alignment with three different size nock sleeves or nock adaptors 102 a , 102 b and 102 c . Each adaptor has a different outside diameter (OD) corresponding to certain common inside diameters (ID) of arrow shafts 104 . For example, adaptor 102 a for 0.204 inch shaft ID, adaptor 102 b for 0.233 inch shaft ID and adaptor 102 c for 0.244 inch shaft ID are all shown. Other adaptor sizes can be provided without departing from the scope of the invention.
[0046] The inside diameter of each of the nock adaptors 102 a , 102 b and 102 c is the same so that a single lighted nock assembly 100 can be used universally with all of the different OD size adapters. In one example, the inside diameter of the adaptors is 0.165 inches. In this example, the outside diameter of the portion of the nock assembly 100 that is inserted into the adaptor is sized to fit 0.165 inch ID arrow shafts. Thus, the nock assembly 100 would be used without an adapter for 0.165 inch ID arrow shafts, and with a respective adaptor 102 a , 102 b and 102 c for 0.204, 0.233 and 0.244 inch shaft IDs. Currently 0.165 inch shaft IDs are the smallest widely used by hunters, but the present invention can be adapted to smaller shafts and used with a wider variety of adaptors without departing from the scope of the invention.
[0047] The feature of using one standard nock size with a variety of adaptors to fit with a variety of different arrow ID shafts reduces the need for manufacturing more than one size lighted nock. This feature also eliminates the need for the store to maintain inventory and merchandise more than one lighted nock size. The user also cannot accidentally purchase the wrong size of lighted nock for their particular shaft ID. Furthermore, the user now has the ability to use the same lighted nock for multiple arrow shaft ID sizes that they may use for targets or hunting by simply moving the lighted nock from shaft to another with the use of the adaptors that are all provided in the original package (kit).
[0048] A single “universal fit” package or kit 106 can be provided, as shown in FIG. 2 , that contains one or more lighted nock assemblies 100 and a variety of nock adaptors 102 a , 102 b and 102 c , each in a plurality of sizes. In a preferred embodiment, there is the same number of nock adaptors as the number of lighted nock assemblies 100 . More or fewer numbers of nock assemblies and knock adaptors can be provided in a single package without departing from the scope of the invention. Additionally, an instruction sheet can be disposed in the package or the instructions can be incorporated into the packaging itself.
[0049] The packaging comprises a full or partial plastic shell 108 including joined front and back panels in a preferred embodiment. An aperture 109 can be defined adjacent the top edge to allow for hanging by a post in the store display.
[0050] Referring now to FIG. 3 , the lighted nock system or device 100 components are shown. The nock assembly comprises a nock body 110 , a battery/LED assembly 112 , a nock activation collar 114 disposed around the outside diameter of the first end of the nock body 110 , and a nock housing portion 116 . The LED end of the battery/LED assembly 112 is secured to the nock body 110 . The second end of the nock body 110 defines a channel portion configured to receive the string of the bow. The housing portion 116 includes a first end configured for insertion into the inside diameter of the arrow shaft and a second end that defines an aperture for receiving the first end of the nock body 110 . Raised male index tabs 118 adjacent the first end of the nock body are configured to engage respective recessed female index slots 119 defined in the second end of the housing 116 .
[0051] The lighted nock system is assembled by securing the LED end of the LED/Battery assembly 112 to the nock body 110 via the first end of the nock body. In one embodiment, ultraviolet curable glue is used to accomplish the securing. Other securing methods and means can also be employed. For example, heat staking or ultrasonically welding the nock body to the LED end of the LED/Battery assembly can be used. A mechanical pin or “C” clip can also be driven through the nock body and the LED end of the LED/Battery assembly to join the two components in other alternatives.
[0052] The activation collar 114 is slid over the first end of the nock body 110 with the teeth facing away from the first end. The activation collar is installed with the LED in the “Off” or deactivated position, as will be discussed in detail below, to set the activation gap 180 for the lighted nock 100 . Then the nock body assembly is mated with the nock housing 116 by inserting the first end of the nock body into the receiving end (second end) of the housing 116 until the components are fit together.
[0053] The battery end of the LED/battery assembly 112 is then secured to the housing 116 . In the illustrated embodiment, the distal end of the battery portion is secured via a battery retention screw 124 that tightens the two halves 122 of the first end together to close the gap 120 , which grips the battery portion securely. Alternatively, the battery portion can be glued in place or attached in a similar manner to the LED end as discussed previously. In the glued embodiment, the first end of the housing 116 need not be configured to form the gap 120 . A simple bore can be provided with the necessary clearance for the battery portion distal end.
[0054] The lighted nock assembly 100 is rotationally indexable with respect to the arrow shaft in which it is inserted. The activation collar 114 includes a raised index tab 125 (shown in FIGS. 14-16 ) on the outside of the part to indicate a visual alignment target with the odd colored vane “Cock Vane” of the arrow. The lighted nock assembly 100 is installed into the arrow shaft with this index mark 125 aligned with the cock vane. This indexability feature is an advantage over other conventional lighted nocks because the present invention can be aligned to the stiff part of the arrow “spine” and cannot rotate out of position after several shots.
[0055] Another advantage of certain embodiments is that the index position will not be lost by operation of the lighted nock assembly. The raised male index tabs 118 of the nock body 110 engage the recessed female index slots 119 of the housing 116 when the two components are secured together. This configuration prevents rotation of the nock body 110 with respect to the nock housing 116 , while permitting these respective components to still move longitudinally with respect to one another.
[0056] Referring to FIGS. 4-5 , the LED/battery assembly 112 comprises an LED portion 126 and a battery portion 128 . The LED/battery assembly is commercially available as a complete assembly from companies such as SHENZHEN POWER STATIONS LTD. and details of such suitable LED/battery assembly is disclosed in Chinese Patent 201636546, entitled “Electronic luminous rod and electronic product.” Other suitable LED/battery assemblies can also be used without departing from the scope of the invention. The use of commercially available LED/battery assemblies allows for embodiments of the invention wherein the batteries and/or LED/Battery assemblies can be replaced.
[0057] The LED light can be of any brightness and color desired by the user. The battery is preferably a lithium type battery due to the size/capacity advantages of such type. However, other battery types can be used (including multiple batteries in series or parallel) without departing from the scope of the invention.
[0058] The LED/battery assembly 112 shown in FIGS. 4-5 appears in the off or deactivated state. In the off state, the LED portion 126 is spaced longitudinally away from the battery portion 128 to define a gap 129 between the respective portions. In this state, the circuit between the battery and LED components is open. The LED is activated, or turned on, by applying a force to contract the two portions 126 and 128 together to reduce or eliminate the gap 129 . Closing the gap completes the internal circuit to energize the LED. The gap 129 is opened again by applying force to pull the two portions 126 and 128 apart to open the gap, thereby turning the LED off. In a preferred embodiment, there is a defined detent at each of the off and on positions so that the on and off positions can be maintained until a deliberate force is applied to move the respective components to the opposite state.
[0059] Referring now to FIGS. 6-13 , various views of the nock body 110 are shown. The nock body 110 has a first end 130 and second end 132 . The first end 130 is shaped to protrude towards the arrow shaft and insert into the nock housing. The first end 130 includes a hollow internal cavity or pocket 134 with a shape and diameter corresponding to the LED/battery assembly 112 so that the assembly can be received within the cavity 134 . The second end 132 defines a channel 136 configured to accept a bow string.
[0060] A portion of the outer surface of the first end portion 130 is provided with a male or raised guide protrusion 138 (also designated as reference 118 in FIG. 3 ). This guide protrusion 138 is longitudinally elongated and has a profile corresponding to the recess in the housing (discussed below). The protrusion/recess pair cooperates to prevent rotation of the nock body 110 with respect to the nock housing 116 . However, longitudinal “in-and-out” movement is permitted in order to allow the gap 129 in the LED/battery assembly to be opened and closed. The figures show two guide protrusions located opposite one another in the figures. However a single protrusion can be used, or more than two such protrusions can be used, without departing from the scope of the invention.
[0061] The second end 132 can take different forms or shapes to suit the particular application. For example, the channel can be eliminated or reduced for cross-bow applications where a relatively deep channel is not utilized.
[0062] A nock alignment tab 140 extends outward from the nock body. This tab 140 allows the user to feel and/or quickly observe the relative rotational position of the activation collar 114 with respect to the nock body 110 .
[0063] The diameter of the first end 130 is smaller than the diameter of the second end 132 . This configuration allows the first end 130 to be inserted into the housing 116 , while the second end 132 remains external to the housing 116 . The interface between the first and second ends forms a stop surface 142 . A plurality of teeth 144 protrude forward from the stop surface 142 toward the first end 130 . The teeth 144 are radially arrayed around the stop surface 142 to define a groove 146 or gap between each of the adjacent teeth.
[0064] Referring to FIGS. 14-17 , the nock activation collar 114 will now be described in further detail. The collar 114 is generally ring-shaped. The inner surface 148 defines an aperture with a diameter slightly larger than the outside diameter of the first end 130 of the nock body 110 . The inner surface also defines relief zones 150 to provide for clearance for the nock body protrusions 138 (or 118 ) through the full range of the collar's rotational travel. The width of the relief zones 150 is selected to define the extent of the rotational travel (e.g. 45 degrees) that the collar 114 can rotate with respect to the nock body 110 . The rotational travel is restricted where the relief zone 150 ends and the male index tab or guide protrusion 118 contacts the interface of the relief zone and inner surface 148 nominal diameter.
[0065] The collar 114 outer surface 152 defines a raised index tab 125 that can be used for indexing of the nock assembly with respect to the arrow shaft, as described herein above. The index tab 125 can also be used for providing a visual and/or touch indication of the relative rotational position of the collar 114 with respect to the nock body 110 .
[0066] A first end surface 154 of the collar spanning between the outer 152 and inner 148 surfaces is generally smooth. This first end 154 in operation faces the housing 116 .
[0067] A second end surface 156 of the collar opposite the first and spanning between the outer 152 and inner 148 surfaces includes a plurality of radially arrayed teeth 158 . A groove 160 or gap is defined between each of the adjacent teeth 158 . This second end 156 in operation faces away from the housing 116 .
[0068] Referring to FIGS. 18-22 , the nock housing 116 will now be described in further detail. The housing 116 has a first end portion 162 configured to be inserted into an adaptor or into the open end of an arrow shaft with an ID of 0.165″. Other diameters are also contemplated. The housing 116 also has an opposing second end portion 164 configured to receive the first end of the nock body 110 and the battery portion of the LED/battery assembly 112 .
[0069] An internal channel 166 extends inwardly from the second end portion 164 and continues forward through a portion of the first end portion 162 , thereby defining a channel depth. The shape and dimensions of the channel 166 conform to the outer dimensions of the first end 130 of the nock body 110 and the protruding portion of the battery portion 128 . The female guide recesses 168 (reference 119 in FIG. 3 ) are defined in the channel corresponding to the male guide protrusions 118 or 138 of the nock body.
[0070] A shaft insertion stop surface 170 is defined at the juncture of the first 162 and second 164 portions of the housing 116 . This stop surface 170 abuts the end surface of the arrow shaft (or an adaptor 102 ) to define the insertion depth of the nock assembly.
[0071] The outer end surface 172 of the second end portion 164 defines a stop surface defining the insertion depth of the nock body 110 until contact is made with the collar 114 . The smooth end 154 of the collar 114 can freely slide against the smooth end surface 172 .
[0072] A tip portion 174 of the first end 162 can be split into a plurality of segments 122 separated by a gap 120 therebetween. A perpendicularly aligned screw hole 174 in one segment and threads in the opposing segment allows the respective segments 122 to be brought together to close the gap 120 by tightening a screw fastener 124 . This tightening action secures the battery end 128 of the LED/battery assembly 112 to the housing 116 . Such securing also secures the nock body 110 to the housing because the LED portion 126 of the LED/battery assembly 112 is also secured to the nock body 110 . Alternatively, the distal battery end of the LED/battery assembly can be secured to the housing 116 by other means, such as glue. In such alternative, the screw and split segments of the tip 174 are unnecessary.
[0073] The battery portion retention screw 124 according to one example embodiment is shown in FIGS. 23-24 . The screw 124 comprises a head 176 configured to engage a screw driver and a threaded body 178 .
[0074] A shaft adaptor 182 for solid core shafts is shown in FIGS. 31-32 . Some arrow shafts, such as those used for bowfishing, are solid, so they do not have a hollow center to allow insertion of the first end of the housing 161 into the arrow shaft. The adaptor 182 has a first end 184 defining a first aperture 186 sized and shaped to receive the first end of the nock housing as if the adaptor 182 were a hollow shaft. The adaptor 182 also has a second end 188 that defines a second aperture 190 sized and shaped to fit over a portion of the rear end of the arrow shaft. The inside diameter of the second aperture 190 closely conforms the arrow shaft's outer diameter for a snug fit. Glue can also be applied to the end of the arrow shaft for added securing of the adaptor 182 to the shaft.
[0075] The operating modes of the lighted nock assembly will now be described with respect to FIGS. 25-30 . FIGS. 25 and 28 illustrate the lighted nock system in the deactivated mode. In this mode, the nock activation collar 114 is rotationally offset 45 degrees counterclockwise with respect to the nock body 110 activation alignment orientation such that each of the tabs or teeth 144 of the nock body 110 abuts a corresponding tooth 158 of the collar 114 . This tooth-to-tooth alignment prevents the activation gap 180 (approximately 0.030 inches—corresponding to the gap 129 of the LED/battery assembly) between the collar 114 and nock body 110 from closing even in the presence of pressure applied to the second end 132 of the nock body 110 . Thus, the LED will not light up even if the arrow is drawn back in the bow and shot.
[0076] The deactivated mode is useful when the lighted mode of the arrow is not desired, such as during storage, transport, loading an arrow onto the bowstring or when target shooting in bright sunlight. It is desirable to practice with the arrow in the same weight and balance configuration as it will be in when hunting or shooting at game (prey) when it is appropriate to have nock light up. Conventional lighted nocks are undesirable to use for practice shooting because the batteries will be used up needlessly. Removing the battery to turn off the nock, if even possible, will dramatically alter the weight and balance of the arrow, so that the practice shot does not predict the arrow as it will be shot with the lighted nock. And repeated removal of the nock can weaken and damage the arrow shaft. The deactivated mode of the present invention therefore solves the above-noted problems with conventional lighted nocks.
[0077] FIGS. 26 and 30 illustrate the lighted nock system in the ready to fire mode. In this mode, the nock activation collar 114 is rotated 45 degrees clockwise from the deactivated alignment noted above such that each of the tabs or teeth 144 of the nock body 110 interleave with the corresponding teeth 158 of the collar 114 . This alignment allows the activation gap 180 between the collar 114 and nock body 110 to close when pressure is applied by the bow string to the second end 132 of the nock body 110 . Thus, the LED will light when the user shoots the arrow as the pressure from the bowstring will compress (close) the activation gap 180 , and thus the gap 129 , to energize the LED. This feature eliminates the possibility of the lighted nock activating when loading an arrow onto the string, which improves shot timing and reduces the likelihood that the prey notices the lit nock.
[0078] FIGS. 27 and 29 illustrate the lighted nock system in the activated mode after the gap 180 has been closed. The LED is now energized by the battery and the nock body 110 is lit.
[0079] The nock assembly can be unlit or turned off by pulling the nock body 110 longitudinally away from the housing 116 to open up the activation gap 180 . This returns the lighted nock assembly to the ready to fire mode. Rotating the collar 114 clockwise with respect to the nock body 110 by 45 degrees engages the deactivated mode.
[0080] As described above, the lighted nock assembly can be turned on and off and set in deactivated mode without the need to remove the nock from the arrow shaft. The nock can be secured to the arrow shaft via any conventional means such as press-fitting, or by the securing method disclosed in U.S. Patent Application Pub. No. 2013/0170900, which is hereby incorporated fully herein as part of this application. The present invention can also be used with a laser broadhead as disclosed in U.S. Patent Application Pub. No. 2012/0035006, which is also hereby incorporated fully herein as part of this application.
[0081] The various components of the arrow insert described herein can be formed from a variety of materials without departing from the scope of the invention. In one embodiment, the universal nock is clear or translucent plastic. The collar 114 and adaptor 102 can be plastic or metal (e.g. aluminum or magnesium). Some components, such as screw 124 are preferably metal. The size and material of screw 124 can be altered to alter weight and weight distribution. Additional weights can be added to the lighted nock assembly internal to the arrow shaft to change arrow weight, weight distribution and flight characteristics as well.
[0082] The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. For example, the invention is also applicable to cross bows, bowfishing, sling bow fishing/hunting, spear fishing guns and other projectiles that would benefit from lighted ends. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.
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A nock body may include a first end and an opposing second end. A nock housing may include a proximal end that engages the first end of the nock body and a distal end opposite the proximal end. A slot may be defined in the nock housing beginning at the distal end that extends in a direction of the proximal end. An LED/battery assembly may be disposed at least partially inside of the nock housing. A fastener may be secured to the nock housing in a location that causes a width of the slot to narrow and secure the LED/battery assembly. A groove may be defined in the nock body beginning at the first end that extends towards the second end. A nock activation lockout can be provided to block an LED activation gap from closing so that the LED does not unintentionally turn on.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of, and claims priority under to, U.S. patent application Ser. No. 14/086,968 to Semenov, filed Nov. 21, 2013, which was published Jun. 5, 2014 as U.S. Patent Application Publication No. 2014/0155740 A1, and which '968 application is a nonprovisional patent application of, and claims priority under 35 U.S.C. §119(e) to, U.S. provisional patent application Ser. No. 61/729,319 to Semenov, filed Nov. 21, 2012 and entitled “ELECTROMAGNETIC TOMOGRAPHY SOLUTIONS FOR SCANNING HEAD.” The foregoing publication and applications are each incorporated herein by reference in their entirety. Additionally, each of the following patents, patent applications and patent application publications is incorporated by reference herein in its entirety:
(a) U.S. Pat. No. 7,239,731 to Semenov et al., issued Jul. 3, 2007 and entitled “SYSTEM AND METHOD FOR NON-DESTRUCTIVE FUNCTIONAL IMAGING AND MAPPING OF ELECTRICAL EXCITATION OF BIOLOGICAL TISSUES USING ELECTROMAGNETIC FIELD TOMOGRAPHY AND SPECTROSCOPY,” which is intended, at least, to provide background and technical information with regard to the systems and environments of the inventions of the current patent application; (b) U.S. Patent Application Publication No. 2012/0010493 A1, which was published Jan. 12, 2012 based on U.S. patent application Ser. No. 13/173,078 to Semenov, filed Jun. 30, 2011 and entitled “SYSTEMS AND METHODS OF 4D ELECTROMAGNETIC TOMOGRAPHIC (EMT) DIFFERENTIAL (DYNAMIC) FUSED IMAGING,” which is intended, at least, to provide explanation of the use of “4D” technology in EMT systems, including with regard to inventions of the current patent application; and (c) U.S. Pat. No. 9,072,449 to Semenov et al., issued Jul. 7, 2015 and entitled “WEARABLE/MAN-PORTABLE ELECTROMAGNETIC TOMOGRAPHIC IMAGING,” which was based on U.S. patent application Ser. No. 13/894,395 to Semenov, filed May 14, 2013 and previously published on Sep. 18, 2014 as U.S. Patent Application Publication 2014/0276012, which is intended, at least, to explain wearable and/or man-portable components of an electromagnetic tomographic imaging system.
COPYRIGHT STATEMENT
[0005] All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in official governmental records but, otherwise, all other copyright rights whatsoever are reserved.
BACKGROUND OF THE PRESENT INVENTION
[0006] 1. Field of the Present Invention
[0007] The present invention relates generally to electromagnetic tomography, and, in particular but not exclusively, to electromagnetic tomography solutions for use with the heads of humans and other animals.
[0008] 2. Background
[0009] Stroke is the 2nd leading cause of death after ischemic heart diseases, and is responsible for 4.4 million deaths (9 percent of all deaths) each year. According to American Heart Association/Stroke Association, every 40 seconds someone in America has a stroke. Every 3 minutes, someone dies of one. Stroke kills more than 137,000 Americans a year. About 795,000 Americans each year suffer a new or recurrent stroke. In Europe there are approximately 1.1 million deaths each year; in the EU there are approximately 460,000 deaths each year caused by stroke disease.
[0010] Stroke is a leading cause of serious, long-term disabilities worldwide, causing significant economic impact. The Potential Years of Life Lost (PYLL) calculated by OECD shows a significant number, which should be preventable.
[0011] Acute ischemic strokes account for about 85% of all strokes; each begins with a blood clot (thrombus) forming in the circulatory system at a site distant from the brain. The clot breaks away from this distant site forming an embolus which then travels through the circulatory system; on reaching the brain, the embolus lodges in the small vessels, interrupting blood flow to a portion of brain tissue. With this reduction in blood flow, tissue damage quickly ensues. Clinical management of stroke has been enhanced by the use of thrombolytics (clot busters) combined with the application of brain imaging techniques that reveal the pathophysiological changes in brain tissue that result from the stroke. In particular, the clinical decision to use a thrombolytic must be made within 3 hours of the onset of symptoms and requires a firm diagnosis of an ischemic stroke. This clinical decision currently relies on imaging methods such as computed tomography (CT) and magnetic resonance imaging (Mill) to reliably determine ischemic perfusion changes. Subsequent management of the stroke is enhanced by imaging the extent of the area of brain tissue with compromised blood flow. Current clinical imaging methods, including CT, positron emission tomography (PET) and MM each offer useful information on tissue properties related to perfusion, ischemia and infarction.
[0012] While each of these methods has its own advantages, none currently offers a rapid or cost effective imaging solution that can be made widely available at the “bedside” in the emergency department or to first response paramedical services. Electromagnetic tomography (EMT), on the other hand, is a relatively recent imaging modality with great potential for biomedical applications, including a non-invasive assessment of functional and pathological conditions of biological tissues. Using EMT, biological tissues are differentiated and, consequentially, can be imaged based on the differences in tissue dielectric properties. The dependence of tissue dielectric properties from its various functional and pathological conditions, such as blood and oxygen contents, ischemia and infarction malignancies has been demonstrated.
[0013] Two-dimensional (2D), three-dimensional (3D) and even “four-dimensional” (4D) EMT systems and methods of image reconstruction have been developed over the last decade or more. Feasibility of the technology for various biomedical applications has been demonstrated, for example, for cardiac imaging and extremities imaging.
[0014] As in any biomedical imaging, the classical EMT imaging scenario consists of cycles of measurements of complex signals, as scattered by a biologic object under study, obtained from a plurality of transmitters located at various points around the object and measured on a plurality of receivers located at various points around the object. This is illustrated in FIG. 1 . As recounted elsewhere herein, the measured matrix of scattered EM signals may then be used in image reconstruction methods in order to reconstruct 3D distribution of dielectric properties of the object, i.e., to construct a 3D image of the object.
[0015] Generally, it is very important for image reconstruction to precisely describe a distribution of EM field with an imaging domain 21 . The distribution of EM field with an imaging chamber is a very complex phenomenon, even when there is no object of interest inside.
[0016] FIG. 2 is a schematic view of a prior art EM field tomographic spectroscopic system 10 . Such a system 10 could carry out functional imaging of biological tissues and could also be used for a non-invasive mapping of electrical excitation of biological tissues 19 using a sensitive (contrast) material (solution or nanoparticles) injected into the biological tissue 19 or carried in the circulation system, characterized by having dielectric properties that are a function of electrical field, generated by biological excited tissue 19 . As illustrated in FIG. 2 , the system 10 included a working or imaging chamber 12 , a plurality of “EM field source-detector” clusters 26 , an equal number of intermediate frequency (“IF”) detector clusters 28 , and a control system (not shown). Although only two EM field source-detector clusters 26 and two IF detector clusters 28 are shown, a much larger number of each are actually used.
[0017] The imaging chamber 12 is a watertight vessel of sufficient size to accommodate a human body or one or more parts of a human body together with a matching liquid. The imaging chamber 12 and its EM field clusters 26 , as well as the IF detector clusters 28 , have sometimes been mounted on carts in order to permit the respective components to be moved if necessary, and the carts may then be locked in place to provide stability.
[0018] Oversimplified, the system 10 operates as follows. An object of interest (e.g., biological tissue) is placed in the imaging domain 21 . The transmitting hardware generates electromagnetic (EM) radiation and directs it to one of the antennas. This antenna transmits electromagnetic waves into imaging domain 21 , and all of the other antennas receive electromagnetic waves that have passed through some portion of the imaging domain 21 . The receiving hardware detects the resulting signal(s), and then the same cycle is repeated for the next antenna and the next one until all antennas have served as a transmitter. The end result is a matrix of complex data which is transmitted to one or more computers in the control system that process the data to produce an image of the object 19 in the imaging domain 21 . An algorithm called an “inversion” algorithm is utilized in this process.
[0019] Electromagnetic tomography uses non-ionizing electromagnetic radiation to differentiate between human tissues. Using a compact antenna design, it creates a low power EM field (less than used in cellular phones), which interacts with the biological object and is then measured by sensors. Special imaging algorithms are then used to inverse a “data tensor” and reconstruct a 3D distribution of dielectric properties within a biological subject inside the EM field—i.e. to obtain a so-called “image tensor” or, simply, an image of the object. These imaging algorithms are in very general terms similar to the ones used in classical imaging methods (such as back-projection method used in Computed Tomography (CT)). However, the wave nature of propagation of EM waves needs to be accounted for in imaging algorithms, siginificantly complicating them. In addition, EMT imaging of the brain presents a significant challenge, as the brain is an object of interest that is located inside a high dielectric contrast shield, comprising the skull (with low dielectric contrast (ε˜10-15) and cerebral spinal fluid (with high ε˜55-60)).
[0020] The images are possible due to the contrast in dielectric properties of various tissues. The contrasts in dielectric properties can also be mapped between normal tissues and tissues under different functional or pathological conditions (functional contrasts). Examples include: malignancies in breast, liver and lung; tissue blood content/flow; hypoxia; ischemia; infarction; compartmental injury; stroke; and brain trauma.
[0021] Unfortunately, existing EMT solutions are not well-suited for certain applications. In this regard, FIGS. 4 and 5 are schematic illustrations of two three-dimensional settings for the system of FIG. 2 . As evident therefrom, conventional EMT imaging chambers are oriented vertically so as to hold the matching liquid. Such an arrangement makes it very difficult to use the technology to image a human head because of the inconvenience of positioning a patient's head in the imaging chamber. This is particularly problematic in the emergency setting, where a patient may not be capable of positioning himself in an arrangement that allows him to insert his head into the imaging chamber. As a result, current implementations of EMT technology are not very suitable for use in diagnosing or treating stroke. Thus, a need exists for a safe, portable and cost-effective supplement to current imaging modalities for acute and chronic assessment of cerebral vascular diseases, including stroke. In particular, a need exists for the use of EMTensor technology in a mobile setting, such as in an ambulance or helicopter, and continual, safe and cost effective monitoring of an efficacy of treatment in ICUs and other medical facilities.
SUMMARY OF THE PRESENT INVENTION
[0022] Broadly defined, the present invention according to one aspect is an electromagnetic tomography (EMT) system for imaging a human head, as shown and described.
[0023] Broadly defined, the present invention according to another aspect is an electromagnetic tomography (EMT) system for imaging a human head, including: an integrated scanning apparatus; and a hub computer system.
[0024] In a feature of this aspect, the integrated scanning apparatus includes an imaging chamber. In a further feature, the imaging chamber is vertically oriented such that a human head may be inserted horizontally into the imaging chamber.
[0025] In another feature of this aspect, the integrated scanning apparatus houses a plurality of rings of antennas. In further features, each ring of the plurality of rings is vertically oriented; the rings of the plurality of rings are concentric with each other; and/or the rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only.
[0026] In further features pertaining to the first and second sets of rings, the second set of rings is divided into two subsets, and the first set of rings of antennas is located between the two subsets; the first subset of rings includes one ring; and/or the second subset of rings includes four rings.
[0027] In a further feature pertaining to the rings, each ring includes 32 antennas.
[0028] In another feature of this aspect, the integrated scanning apparatus is man-portable.
[0029] In another feature of this aspect, the integrated scanning apparatus and hub computer system are transportable. In a further feature, the integrated scanning apparatus and hub computer system are mobile.
[0030] Broadly defined, the present invention according to another aspect is an integrated scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system, as shown and described.
[0031] Broadly defined, the present invention according to another aspect is an integrated scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system, including: a housing defining a vertically oriented imaging chamber in which a human head may be inserted horizontally; and an array of antennas.
[0032] In a feature of this aspect, the integrated scanning apparatus is transportable. In a further feature, the integrated scanning apparatus is mobile. In a still further feature, the integrated scanning apparatus is man-portable.
[0033] In another feature of this aspect, the array of antennas is arranged in a plurality of rings of antennas. In further features, the rings of the plurality of rings are concentric with each other; the rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only; and/or each ring includes 32 antennas.
[0034] In further features pertaining to the first and second sets of rings, the second set of rings is divided into two subsets, and the first set of rings of antennas is located between the two subsets; the first subset of rings includes one ring; and/or the second subset of rings includes four rings.
[0035] Broadly defined, the present invention according to another aspect is a wearable scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system, as shown and described.
[0036] Broadly defined, the present invention according to another aspect is a method of treating a stroke patient using an electromagnetic tomography (EMT) system, as shown and described.
[0037] Broadly defined, the present invention according to another aspect is a method of treating a stroke patient using an electromagnetic tomography (EMT) system, including: in response to an emergency report and request from or on behalf of stroke patient, providing an ambulance equipped with a scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system; placing the scanning apparatus on or around the stroke patient's head; carrying out an EMT scanning process; providing data from the EMT scanning process to a hub computer system; producing EMT image results based on the provided data; and providing the EMT image results to a medical practitioner at a treatment center for use in diagnosing or treating the stroke patient upon the patient's arrival at the treatment center.
[0038] Broadly defined, the present invention according to another aspect is an image chamber unit for gathering measurement data pertaining to a human head in an electromagnetic tomography (EMT) system, including: an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, wherein the transmitting antennas transmit a low power electromagnetic field, wherein the receiving antennas receive the low power electromagnetic field after passing through a human head in the imaging chamber and provide corresponding signals to a control system so as to produce a data tensor that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object; and a housing, at least partially containing the antenna assembly, having a front entry opening into the imaging chamber. The head of a human patient may be inserted horizontally through the front entry opening and into the imaging chamber.
[0039] In a feature of this aspect the antenna assembly includes a plurality of antenna disks, each antenna disk including an array of antennas. Each antenna disk includes a center opening, wherein the imaging chamber is at least partially defined by the plurality of center openings. The antenna disk center openings are circular and collectively define a cylindrical portion of the imaging chamber. The antenna assembly further includes a back disk attached to a rear of the antenna disks, wherein the back disk closes and defines a rear of the horizontally-oriented imaging chamber.
[0040] In a further feature, the array of antennas on each antenna disk is arranged in a ring whose center axis is oriented horizontally. The rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only. The second set of rings is divided into two subsets, and wherein the first set of rings of antennas is located between the two subsets. The first subset of rings includes one ring. The second subset of rings includes four rings. Each ring includes 32 antennas.
[0041] In another feature of this aspect, the image chamber unit further includes a flexible membrane separating a front portion of the imaging chamber from a rear portion of the imaging chamber. The flexible membrane conforms to a portion of the shape of a human head when the human head is inserted through the front entry opening and into the front portion of the imaging chamber. The rear portion of the imaging chamber is filled with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the back disk includes at least one inlet for pumping the matching liquid into the rear portion of the imaging chamber. In a further feature of this aspect the image chamber unit of, further includes a catch basin disposed adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube. In a further feature of this aspect the image chamber further includes a sanitary protective cap disposed in front of and against the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane. In yet a further feature of this aspect the image chamber further includes a protective ring around the entry opening to protect the human head from injury when inserting the head through the entry opening.
[0042] Broadly defined, the present invention according to another aspect is an electromagnetic tomography (EMT) system for gathering measurement data pertaining to a human head, including: an image chamber unit including an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, a control system that causes the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through a human head in the imaging chamber and produces a data tensor from resulting signals that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object; and a housing, at least partially containing the antenna assembly, having a front entry opening into the imaging chamber. The head of a human patient may be inserted horizontally through the front entry opening and into the imaging chamber.
[0043] In a feature of this aspect the antenna assembly includes a plurality of antenna disks, each antenna disk including an array of antennas. Each antenna disk includes a center opening, wherein the imaging chamber is at least partially defined by the plurality of center openings. The antenna disk center openings are circular and collectively define a cylindrical portion of the imaging chamber. The antenna assembly further includes a back disk attached to a rear of the antenna disks, wherein the back disk closes and defines a rear of the horizontally-oriented imaging chamber. In a feature of this aspect, the array of antennas on each antenna disk is arranged in a ring whose center axis is oriented horizontally. The rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only. The second set of rings is divided into two subsets, and wherein the first set of rings of antennas is located between the two subsets. The first subset of rings includes one ring. The second subset of rings includes four rings. Each ring includes 32 antennas.
[0044] In another feature, the image chamber unit further includes a flexible membrane separating a front portion of the imaging chamber from a rear portion of the imaging chamber. The flexible membrane conforms to a portion of the shape of a human head when the human head is inserted through the front entry opening and into the front portion of the imaging chamber. The rear portion of the imaging chamber is filled with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the back disk includes at least one inlet for pumping the matching liquid into the rear portion of the imaging chamber. In a further feature of this aspect the image chamber unit of, further includes a catch basin disposed adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube. The catch basin is attached to the image chamber unit. The catch basin is separate from, but positioned next to, the image chamber unit.
[0045] In a further feature of this aspect the image chamber further includes a sanitary protective cap disposed in front of and against the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane. In yet a further feature of this aspect the image chamber further includes a protective ring around the entry opening to protect the human head from injury when inserting the head through the entry opening.
[0046] In another feature, the electromagnetic tomography (EMT) system further included a patient support. The patient support includes a headrest extending therefrom so as to position and/or orient a patient's head within the imaging chamber. The image chamber unit is disposed on top of the patient support, on one end thereof, and wherein the control system is carried beneath the patient support.
[0047] In another feature, the electromagnetic tomography (EMT) system further included a hydraulic system supplying liquid to the imaging chamber. The hydraulic system includes a holding tank for the liquid and a pump. The holding tank is a first tank, wherein the hydraulic system further includes a second internal tank, and wherein the liquid flows from the first tank to the imaging chamber and from the imaging chamber to the second tank. In a further feature of this aspect an inline valve is disposed between the first tank and the imaging chamber. In a further feature of this aspect a backflow valve is disposed between the imaging chamber and the second tank. In a further feature of this aspect a check valve is disposed between the imaging chamber and the second tank in parallel with the backflow valve. In a further feature of this aspect a temperature sensor is disposed at an inlet to the imaging chamber. A heater to raise the temperature of the liquid based on the status of the temperature sensor. A liquid sensor that prevents heating if liquid is not present in the second tank. In a further feature of this aspect, the electromagnetic tomography (EMT) system includes an overflow path from the second tank. The overflow path connects the second tank back to the first tank. The pump includes a remote control. The pump is a bi-directional pump.
[0048] Broadly defined, the present invention according to another aspect is an image chamber unit for gathering measurement data pertaining to a human head in an electromagnetic tomography (EMT) system, including: an antenna assembly at least partially defining a imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, wherein the transmitting antennas transmit a low power electromagnetic field, wherein the receiving antennas receive the low power electromagnetic field after passing through a human head in the imaging chamber and provide corresponding signals to a control system so as to produce a data tensor that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object; a housing, at least partially containing the antenna assembly, having an entry opening into the imaging chamber; a flexible membrane separating a first portion of the imaging chamber from a second portion of the imaging chamber. The the head of a human patient may be inserted through the front entry opening and into the imaging chamber.
[0049] In a feature of this aspect the imaging chamber is horizontally-oriented, wherein the entry opening is a front entry opening, wherein the first portion of the imaging chamber is at a front of the imaging chamber near the front entry opening, and wherein the second portion of the imaging chamber is at a rear of the imaging chamber such that the flexible membrane separates the front portion of the imaging chamber from the rear portion of the imaging chamber. The flexible membrane conforms to a portion of the shape of a human head when the human head is inserted through the front entry opening and into the front portion of the imaging chamber. the rear portion of the imaging chamber is filled with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine.
[0050] In a further feature the antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the back disk includes at least one inlet for pumping the matching liquid into the rear portion of the imaging chamber.
[0051] In a further feature the image chamber unit further includes a catch basin disposed adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube. In a further feature of this aspect the image chamber further includes a sanitary protective cap disposed in front of and against the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane.
[0052] In a further feature the antenna assembly includes a plurality of antenna disks, each antenna disk including an array of antennas. Each antenna disk includes a center opening, wherein the imaging chamber is at least partially defined by the plurality of center openings. The antenna disk center openings are circular and collectively define a cylindrical portion of the imaging chamber. The antenna assembly further includes a back disk attached to a rear of the antenna disks, wherein the back disk closes and defines a rear of the horizontally-oriented imaging chamber. The array of antennas on each antenna disk is arranged in a ring whose center axis is oriented horizontally The rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only. The second set of rings is divided into two subsets, and wherein the first set of rings of antennas is located between the two subsets. The first subset of rings includes one ring. The second subset of rings includes four rings. Each ring includes 32 antennas.
[0053] In a further feature the image chamber further includes a protective ring around the entry opening to protect the human head from injury when inserting the head through the entry opening.
[0054] Broadly defined, the present invention according to another aspect is a method of using an electromagnetic tomography (EMT) system to generate a data tensor for imaging a human head, including: positioning a patient on his back on a patient support; inserting the head of the patient horizontally through a front entry opening of an image chamber unit, the image chamber unit including an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas; and using a control system, causing the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through the patient's head in the imaging chamber and producing a data tensor from resulting signals that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the patient's head. The image chamber unit includes a housing that at least partially contains the antenna assembly, wherein the front entry opening is in the housing, and wherein the method further includes providing a membrane, within the imaging chamber, that separates a front portion of the imaging chamber from a rear portion.
[0055] In a feature of this aspect, the method includes a step of conforming the flexible membrane to a portion of the shape of the patient's head when the head is inserted through the front entry opening and into the front portion of the imaging chamber.
[0056] In a feature of this aspect, the method further includes a step of filling the rear portion of the imaging chamber with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the method further includes pumping the matching liquid into the rear portion of the imaging chamber through at least one inlet in the back disk. In a further feature of this aspect the method further includes a step of positioning a catch basin adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube.
[0057] In a further feature the method includes a step of placing a sanitary protective cap over the patient's head so that the protective cap is disposed between the patient's head and the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane.
[0058] Broadly defined, the present invention according to another aspect is a method of using an electromagnetic tomography (EMT) system to generate a data tensor for imaging a human head, including: in response to an emergency report and request from or on behalf of stroke patient, providing an ambulance equipped with an image chamber unit for gathering measurement data pertaining to a human head in an electromagnetic tomography (EMT) system, the image chamber unit including: an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, wherein the transmitting antennas transmit a low power electromagnetic field, wherein the receiving antennas receive the low power electromagnetic field after passing through a human head in the imaging chamber and provide corresponding signals to a control system so as to produce a data tensor that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object, and a housing, at least partially containing the antenna assembly, having a front entry opening into the imaging chamber; positioning the stroke patient on his back on a patient support; inserting the head of the patient horizontally through the front entry opening of the image chamber unit and into the imaging chamber; using a control system, causing the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through the patient's head in the imaging chamber and producing a data tensor from resulting signals that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the patient's head; providing the data tensor to a hub computer system; producing EMT image results based on the provided data; and providing the EMT image results to a medical practitioner at a treatment center for use in diagnosing or treating the stroke patient upon the patient's arrival at the treatment center.
[0059] In a feature of this aspect, the method further includes providing a membrane, within the imaging chamber, that separates a front portion of the imaging chamber from a rear portion. In a further feature of this aspect, the method further includes a step of conforming the flexible membrane to a portion of the shape of the patient's head when the head is inserted through the front entry opening and into the front portion of the imaging chamber. In a further feature of this aspect, the method further includes a step of filling the rear portion of the imaging chamber with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The the antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the method further includes pumping the matching liquid into the rear portion of the imaging chamber through at least one inlet in the back disk.
[0060] In a further feature the method includes the step of positioning a catch basin adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube.
[0061] In yet a a further feature the method includes the step of placing a sanitary protective cap over the patient's head so that the protective cap is disposed between the patient's head and the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane
[0062] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. 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
[0063] Further features, embodiments, and advantages of the present invention will become apparent from the following detailed description with reference to the drawings, wherein:
[0064] FIG. 1 is a graphical illustration of the principle of electromagnetic tomography (EMT);
[0065] FIG. 2 is a schematic view of a prior art EM field tomographic spectroscopic system;
[0066] FIG. 3 is a schematic diagram illustrating the operation of the system of FIG. 1 in a two-dimensional context;
[0067] FIGS. 4 and 5 are schematic illustrations of two three-dimensional settings for the system of FIG. 2 ;
[0068] FIG. 6 is a front isometric view of an EMT system for imaging a human head in accordance with one or more preferred embodiments of the present invention;
[0069] FIG. 7 is a front plan view of the EMT system of FIG. 6 ;
[0070] FIG. 8 is a rear perspective view of the EMT system of FIG. 6 ;
[0071] FIG. 9 is a cross-sectional, partially schematic, right side view of the image chamber unit of FIG. 7 , taken along line 9 - 9 ;
[0072] FIG. 10 is a view of the image chamber unit similar to that of FIG. 9 , but shown with a patient support and a catch basin in place adjacent the unit;
[0073] FIG. 11 is a view of the image chamber unit similar to that of FIG. 10 , but shown with an upper portion of a patient's head inserted into the entry opening;
[0074] FIGS. 12 and 13 are a rear isometric view and a rear plan view, respectively, of the membrane of the image chamber unit of FIG. 6 ;
[0075] FIG. 14 is a side cross-sectional view of the membrane of FIG. 13 , taken along line 14 - 14 ;
[0076] FIG. 15 is a view of the image chamber unit similar to that of FIG. 11 , but shown with a fluid disposed within the working chamber on the opposite side of the membrane from the patient's head;
[0077] FIG. 16 is a schematic diagram of the hydraulic system of FIG. 8 ;
[0078] FIG. 17 is a left front isometric view of portions of the disk assembly of FIG. 9 ;
[0079] FIG. 18 is a schematic representation of concentric rings of antennas;
[0080] FIG. 19 is a top cross-sectional view of the disk assembly of FIG. 17 , taken along line 19 - 19 ;
[0081] FIG. 20 is a front view of one of the antenna disks of FIG. 19 ;
[0082] FIG. 21 is a top cross-sectional view of the antenna disk of FIG. 20 ;
[0083] FIG. 22 is a schematic diagram of the EMT system of FIG. 6 ;
[0084] FIG. 23 is a schematic representation of the operation of the rings of antennas around the imaging domain;
[0085] FIGS. 24A and 24B are a more detailed schematic diagram of the control system of FIG. 22 ;
[0086] FIG. 25 is a schematic diagram of one of the transmitting/receiving switch units of FIG. 22 ;
[0087] FIG. 26 is a schematic diagram of one of the receiving switch units of FIG. 22 ;
[0088] FIG. 27 is a schematic diagram of the power unit of FIG. 22 ;
[0089] FIG. 28 is a schematic block diagram of additional or alternative details of a control system for the EMT system;
[0090] FIGS. 29 and 30 are a top front perspective view and a bottom rear perspective view, respectively, of another EMT system for imaging a human head in accordance with one or more preferred embodiments of the present invention;
[0091] FIG. 31 is a top plan view of the system in use in an ambulance;
[0092] FIG. 32 is a side perspective view of a cap serving as a wearable image chamber unit in accordance with one or more preferred embodiments of the present invention; and
[0093] FIG. 33 is a pictorial illustration of a timeline for use of an EMT system, including the cap of FIG. 32 , for imaging a human head in response to the onset of stroke symptoms in a patient.
DETAILED DESCRIPTION
[0094] As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art (“Ordinary Artisan”) that the present invention has broad utility and application. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the present invention. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure of the present invention. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the invention and may further incorporate only one or a plurality of the above-disclosed features. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.
[0095] Accordingly, while the present invention is described herein in detail in relation to one or more embodiments, it is to be understood that this disclosure is illustrative and exemplary of the present invention, and is made merely for the purposes of providing a full and enabling disclosure of the present invention. The detailed disclosure herein of one or more embodiments is not intended, nor is to be construed, to limit the scope of patent protection afforded the present invention, which scope is to be defined by the claims and the equivalents thereof. It is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.
[0096] Thus, for example, any sequence(s) and/or temporal order of steps of various processes or methods that are described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal order, the steps of any such processes or methods are not limited to being carried out in any particular sequence or order, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and orders while still falling within the scope of the present invention. Accordingly, it is intended that the scope of patent protection afforded the present invention is to be defined by the appended claims rather than the description set forth herein.
[0097] Additionally, it is important to note that each term used herein refers to that which the Ordinary Artisan would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—as understood by the Ordinary Artisan based on the contextual use of such term—differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by the Ordinary Artisan should prevail.
[0098] Regarding applicability of 35 U.S.C. §112, ¶6, no claim element is intended to be read in accordance with this statutory provision unless the explicit phrase “means for” or “step for” is actually used in such claim element, whereupon this statutory provision is intended to apply in the interpretation of such claim element.
[0099] Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one,” but does not exclude a plurality unless the contextual use dictates otherwise. Thus, reference to “a picnic basket having an apple” describes “a picnic basket having at least one apple” as well as “a picnic basket having apples.” In contrast, reference to “a picnic basket having a single apple” describes “a picnic basket having only one apple.”
[0100] When used herein to join a list of items, “or” denotes “at least one of the items,” but does not exclude a plurality of items of the list. Thus, reference to “a picnic basket having cheese or crackers” describes “a picnic basket having cheese without crackers,” “a picnic basket having crackers without cheese,” and “a picnic basket having both cheese and crackers.” Finally, when used herein to join a list of items, “and” denotes “all of the items of the list.” Thus, reference to “a picnic basket having cheese and crackers” describes “a picnic basket having cheese, wherein the picnic basket further has crackers,” as well as describes “a picnic basket having crackers, wherein the picnic basket further has cheese.”
[0101] Referring now to the drawings, in which like numerals represent like components throughout the several views, one or more preferred embodiments of the present invention are next described. The following description of one or more preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0102] FIG. 6 is a front isometric view of an EMT system 110 for imaging a human head 19 in accordance with one or more preferred embodiments of the present invention, FIG. 7 is a front plan view of the EMT system 110 of FIG. 6 , and FIG. 8 is a rear perspective view of the EMT system 110 of FIG. 6 . As shown therein, the system 110 includes an image chamber unit 131 , a control cabinet 135 , a hydraulic system 140 for supplying, circulating, and otherwise managing a matching fluid to the image chamber unit 131 , and a rolling carriage 132 . In at least some embodiments, the image chamber unit 131 and the control cabinet 135 are housed together in a single enclosure 134 and are supported on a rolling carriage 132 . Furthermore, in at least some embodiments, some or all of the hydraulic system 140 is supported on the rolling carriage 132 as well. However, in some embodiments, the image chamber unit 131 and control cabinet 135 are separate from each other and each may or may not be carried on its own rolling carriage. In some of these embodiments, the image chamber unit 131 and control cabinet 135 are not located in the same room. Although not illustrated in FIGS. 6-8 , the system 110 also includes a user interface computer 208 , described elsewhere herein, which may be connected to the rest of the system 110 via Ethernet or other port 136 located on the side of the control cabinet 131 .
[0103] FIG. 9 is a cross-sectional, partially schematic, right side view of the image chamber unit 131 of FIG. 7 , taken along line 9 - 9 . As shown therein, the image chamber unit 131 includes a disk assembly 126 , a membrane 133 , and fluid inlets 167 , 168 . The disk assembly 126 includes a plurality of antenna disks 170 and a back disk 183 , wherein at least the antenna disks 170 are open in their centers. The center openings of the antenna disks 170 together with the back disk 183 at least partially define a “working” chamber or “imaging” chamber 122 . In at least some embodiments, the antenna disk center openings are circular, and the circular openings thus define a cylindrical portion of the working chamber 122 (perhaps best seen in FIG. 17 ), which simplifies the operation of the tomography somewhat, but in other embodiments the center openings and working chamber 122 may take on other shapes. In at least some embodiments, the volume of the working chamber 122 is approximately 12 liters.
[0104] The center opening of the frontmost antenna disk 170 defines an entry opening 169 for receiving a patient. The entry opening 169 is preferably surrounded by a protective ring 182 (shown in FIGS. 6 and 7 ) covering the surfaces of the antenna disk 170 and other portions of the working chamber 122 . FIG. 10 is a view of the image chamber unit 131 similar to that of FIG. 9 , but with a patient support 120 and a catch basin 165 in place adjacent the unit 131 , and FIG. 11 is a view of the image chamber unit 131 similar to that of FIG. 10 but shown with an upper portion of a patient's head 19 inserted into the entry opening. For comfort and convenience, the patient may be positioned on the patient support 120 , which may be a gurney, cart, table, stretcher, or the like. In at least some embodiments of the present invention, a headrest 118 extends from the end of the patient support 120 . The headrest 118 is preferably padded and adjustable. Adjustability of the headrest 118 may be provided in one or more of the longitudinal direction (toward or away from the end of the patient support 120 ), the vertical direction (up or down relative to the patient support 120 ), and rotationally (for example, about an axis that is parallel with the end of the patient support 120 ). In the illustrated embodiment, the entry opening and the working chamber 122 are sized to correspond specifically to a human head, but it will be appreciated that other dimensions may be utilized for other body parts or to accommodate the entirety of a human body. The entry opening is substantially liquid-sealed by the membrane 133 such that the front of the working chamber 122 is separated by the membrane 133 from the rear of the chamber 122 . Fluid leaks through the front of the working chamber 122 , such as around or through the membrane 133 , may be captured in the catch basin 165 disposed in front of the unit 131 . It is contemplated that the catch basin 165 can be integral with or otherwise part of the image chamber unit 131 .
[0105] FIGS. 12 and 13 are a rear isometric view and a rear plan view, respectively, of the membrane 133 of the image chamber unit 131 of FIG. 6 , and FIG. 14 is a side cross-sectional view of the membrane 133 of FIG. 13 , taken along line 14 - 14 . The membrane 133 is preferably somewhat hat-shaped, with a center crown portion 127 extending “upward” or “inward” from an outer brim portion 128 . The brim portion 128 is shaped to be fastened to the antenna disks 170 and may include apertures 129 for this purpose. As shown in FIG. 14 , the crown portion 127 may be thinner than the brim portion 128 and is preferably flexible enough to wrap snugly around the patient's head 19 , as shown in FIG. 11 . In at least some embodiments, the membrane 133 is made of latex or similar material.
[0106] FIG. 15 is a view of the image chamber unit 131 similar to that of FIG. 11 but shown with a fluid disposed within the working chamber 122 on the opposite side of the membrane 133 from the patient's head 19 . The fluid may be supplied to or from the working chamber 122 via the inlets 167 , 168 , which may be arranged in or on the back disk 183 . The fluid itself is a “matching” fluid that is chosen for its properties so as to enhance the tomographic process. Flow and other movement of the fluid is controlled by the hydraulic system 140 .
[0107] FIG. 16 is a schematic diagram of the hydraulic system 140 of FIG. 8 . As shown therein, the hydraulic system 140 includes an external tank 141 , a bi-directional pump 142 , a valve 159 , backflow valve 160 , a check (directional) valve 161 , an inner upper tank 146 , one or more liquid sensors 147 , a lighter 148 , one or more temperature sensors 149 , 150 , and a variety of hoses, tubes, fittings, and the like, some of which are described herein. The external tank 141 holds a quantity of a matching fluid. A hose 151 connects the external tank 141 to the pump 142 , and another hose 152 connects the pump 142 to a fitting 153 on the enclosure 134 . In at least some embodiments, the pump hoses 151 , 152 are ¾″ flexible tube hoses, and the hose fitting 153 is a quick release fitting.
[0108] The pump 142 is used to supply matching fluid from the external tank 141 to the working (image) chamber of the image chamber unit 131 . The matching fluid is a solution or gel that is needed or useful inside the imaging chamber when the object 19 is being measured inside it to address electromagnetic body-matching problems. In at least some embodiments, the matching liquid is a mixture of glycerol (Ph. Eur.), water and brine. In at least some embodiments, the pump 142 is connected by cable 154 to a standard power supply, such as a 220V electrical source, which may be provided from the control cabinet 135 via an outlet 137 , preferably located on the outer surface of the enclosure 134 , and a corresponding water proof socket 155 . Direction, speed, and other control of the pump 142 may be provided by remote control 156 . One pump 142 suitable for use in at least some preferred embodiments is a Watson Marlow 620 RE IP66 pump.
[0109] Inside the image chamber unit 131 , another hose 157 is connected between the external fitting 153 and a first inlet 167 to the working chamber, and still another hose 158 is connected between a second inlet 168 to the working chamber and the inner upper tank 146 . In at least some embodiments, the hose 157 is a ¾″ flexible tube hose. An inline valve 159 may optionally be provided in the hose 157 from the pump 134 , while a backflow valve 160 and check (directional) valve 161 may be provided in the hose 158 to the inner upper tank 146 . The backflow valve 160 provides at least two functions. First, when it is closed, the pump 142 may be used to generate an under-pressure, thereby denting in the membrane 133 (as seen from outside the image chamber unit 131 ) and readying the unit 131 for a patient's head to be inserted therein. Second, when the patient's head is positioned inside the membrane 133 , opening the backflow valve 160 allows the matching fluid to flow from the reservoir 146 back to the imaging chamber, which in turn causes the patient's head to be slowly enclosed by the membrane 133 and the liquid. The check valve 161 , on the other hand, performs a safety function by avoiding the buildup of an overpressure if the backflow valve 160 is closed. The check valve 161 includes a manual control lever 181 , as shown in FIG. 6 .
[0110] The temperature sensors 149 , 150 may be used to determine the temperature of the matching fluid inside the working chamber, or in close proximity thereto. If the temperature becomes uncomfortably cool, the lamp or lighter 148 may be utilized to trigger heating of the inner upper tank 146 . Unintentional heating of an empty tank 146 may be avoided by using the liquid sensors 147 to verify that sufficient liquid is present in the tank.
[0111] An overfill path may be provided between the inner upper tank 146 and the external tank 141 so as to return any excess matching liquid to the external tank 141 . The overfill path may include an internal hose 162 , an external hose 163 , and a fitting 164 on the exterior of the enclosure 134 , wherein the internal hose 162 is connected between the inner upper tank 146 and the fitting 164 and the external hose is connected between the fitting 164 and the external tank 141 . Generally, the overfill path is only utilized if the reservoir 146 is accidentally overfilled, in which case the overfill path allows the excess liquid to return to the external tank 141 . In at least some embodiments, the overfill path hoses 162 , 163 are ¾″ flexible tube hoses, and the hose fitting 164 is a quick release fitting.
[0112] A leakage path may also be provided. The leakage path may include a catch basin 165 and a drain hose or tube 166 . The catch basin 165 may be disposed adjacent the working chamber so as to receive fluid escaping therefrom, such as during dismantling of the system 110 . In some embodiments, the drain hose 166 connects the catch basin 165 to the external tank, such as by the overflow path, while in others the drain hose 166 is routed to a waste tank (not shown) and/or is left open or unconnected.
[0113] FIG. 17 is a left front isometric view of portions of the disk assembly 126 of FIG. 9 . As shown therein, the disk assembly 126 includes a plurality of antenna disks 170 arranged concentrically such that their center openings define the interior of the working chamber 122 , as described previously. Notably, whereas traditional EMT systems have used rings of transmitters/receivers/sensors that have been oriented in a horizontal plane to define a vertical working chamber, the rings of transmitter/receivers and receivers of the present invention are each oriented vertically so as to define a horizontal working chamber. Each antenna disk 170 includes a multitude of antennas 173 arranged in a ring around the working chamber 122 . FIG. 18 is a schematic representation of these concentric rings 180 of antennas 173 . Although other numbers of disks 170 and rings 180 may be utilized, five antenna disks 170 and thus five antenna rings 180 are present in the embodiment shown in FIGS. 17 and 18 . Furthermore, although other numbers of antennas 173 may be utilized, 32 antennas 173 are present in the embodiment shown in FIGS. 17 and 18 , and thus a total of 160 antennas 173 are utilized. In one embodiment, preferred for its simplicity, the antennas 173 in the middle ring 180 are both transmitting and receiving antennas, while the antennas 173 on the other four rings 180 are receiving antennas only. In one contemplated embodiment, the rings 180 (i.e., the center openings of the antenna disks 170 ) are 285 mm in diameter. In FIG. 17 , transmitting/receiving antenna “9” on ring “C” is shown as transmitting an electromagnetic field or signal, all or some of which is received at each of various transmitting/receiving antennas on ring “C” and at each of various receiving antennas on rings “A”, “B”, “D”, and “E”. It will be appreciated, however, that any or all of the transmitting/receiving antennas on ring “C” and/or any or all of the receiving antennas on any or all of the other rings may receive the transmitted field or signal and thus may be incorporated into the tomographic process.
[0114] FIG. 19 is a top cross-sectional view of the disk assembly 126 of FIG. 17 , taken along line 19 - 19 ; FIG. 20 is a front view of one of the antenna disks 170 of FIG. 19 , and FIG. 21 is a top cross-sectional view of the antenna disk 170 of FIG. 20 . Notably, some visual detail regarding the electrical connections for the antennas has been omitted in FIG. 17 ; however, much of the omitted visual detail is shown in FIG. 20 . Each antenna disk 170 includes two mating rings 171 , 172 , the antennas 173 themselves, a corner element 174 for each antenna 173 , a cable plate 175 , and a cable assembly 176 for each antenna 173 . Each cable assembly 176 includes a cable and/or conduit with an appropriate terminator 177 , 178 on each end. Screws or other cable positioners 179 are provided to hold the cable assemblies 176 in place.
[0115] FIG. 22 is a schematic diagram of the EMT system 110 of FIG. 6 . As shown therein, the EMT system 110 includes the image chamber unit 131 (including the working chamber 122 ), the hydraulic system 140 , the patient support 120 , and a control system 200 . The control system 200 includes two 16-channel transmitting/receiving switch units 201 for the transmitting/receiving antenna disk 170 , two 16 -channel receiving switch units 202 for each of the receiving antenna disks 170 , a control unit 203 , a network analyzer 204 , a power unit 205 , one or more fan units 206 , a hub 207 , and a user interface computer 208 . In at least some embodiments, the switch units 201 , 202 , control unit 203 , network analyzer 204 , power unit 205 , fan units 206 , and hub 207 are supported on a rack 209 in the control cabinet 135 . The user interface computer 208 may be supported on or in the enclosure 134 or may be supported elsewhere, such as on a nearby desk, a user's lap, or in some cases even outside the room.
[0116] FIG. 23 is a schematic representation of the operation of the rings 180 of antennas 173 around the imaging domain, which is defined by the imaging chamber. The general task is to make complex Si,j,k parameters matrix measurement, where i is the transmitting antenna (i=1 . . . 32), j is the receiving antenna (j=1 . . . 31), and k is the ring of the receiving antenna (k=1 . . . 5). The more practical case for the number of receiving antennas that are measured for each transmitting antenna may be between 12 and 20 (i.e., only receivers generally opposite the transmitting antenna), and the most practical case may be for 17 receiving antennas to be measured for each transmitting antenna, but other numbers are also viable. Typical attenuations may be ˜90 dB to ˜130 dB. In at least some embodiments, frequencies may be 0.8-1.5 GHz, step 50 MHz. In at least some embodiments, channel-to-channel isolation may be ˜80 dB to −100 dB. In at least some embodiments, maximum power output may be +20 dBm (100 mW). In at least some embodiments, single frame data acquisition time may be less than 60 mSec (“frame” being defined as the full cycle of S matrix measurements). In at least some embodiments, the number of acquired frames may be from 1 to 1000. In at least some embodiments, the dielectric properties of the matching media between antennas and object may be ˜(30-to-60)+j(15-to-25).
[0117] FIGS. 24A and 24B are a more detailed schematic diagram of the control system 200 of FIG. 22 . As shown therein, the hub 207 , which may provide both wireless and wired connections, communicatively connects the control unit 203 , the network analyzer 204 , and the user interface computer 208 . The control unit 203 includes a host controller that interfaces with the hub 207 as well as provides a trigger input to the network analyzer 204 and receives “ready for trigger” and/or “busy” signals from the network analyzer 204 . The host controller also receives an ECG input and controls drivers for MW switches. The control unit 203 also includes various circuitry, including amplifiers, multiplexers, and the like, to generate input signals for the ports of the network analyzer 204 , which may be a ZVA 4 port vector network analyzer available from Rohde & Schwarz. The network analyzer 204 is also communicatively connected to the hub 207 , preferably via a LAN, and operations of the control unit 203 and network analyzer 204 are under the control of the user interface computer 208 . Power is supplied by a power converter which may receive 24 V power from the power unit 205 as described elsewhere herein.
[0118] FIG. 25 is a schematic diagram of one of the transmitting/receiving switch units 201 of FIG. 22 , and FIG. 26 is a schematic diagram of one of the receiving switch units 202 of FIG. 22 . FIG. 27 is a schematic diagram of the power unit 205 of FIG. 22 . As shown therein, the AC line input is converted into power for the hub 207 , the network analyzer (VNA) 204 , and for 24V AC/DC converters used to power the control unit 203 and transmitter/receiver and receiver switch units 201 , 202 . FIG. 28 is a schematic block diagram of additional or alternative details of a control system for the EMT system 110 .
[0119] In operation, a patient 15 is placed on his back on a patient support 120 and transported to the image chamber unit 131 , shown in FIG. 9 , or the image chamber unit 131 is transported to the location of the patient 15 . For sanitary purposes, a single-use protective cap (not shown) may be placed over the patient's head 19 . Such a protective cap may be made of plastic, latex, or the like. The patient's head 19 is then inserted into the entry opening 169 in the working chamber 122 as shown in FIG. 11 . The headrest 118 may be adjusted as necessary or desired to arrange the patient's head in the desired position and orientation within the working chamber 122 . The patient's head 19 bears against the membrane 133 , which then conforms to the shape of the patient's head 19 . With the patient's head 19 properly arranged, a technician fills the working chamber with a quantity of the prepared matching liquid. Filling may be carried out using the remote control of the pump, which in at least some embodiments has toggle switches to start and stop the pump, control the direction of flow (in or out), and flow rate. Filling is preferably initiated at a low flow rate to avoid splashing of matching liquid. Matching liquid is pumped into the working chamber until it is full, as shown in FIG. 15 .
[0120] In addition to filling the working chamber with the matching liquid, the technician may also power on the various electronic components, including the control unit, the network analyzer, transmitter and receiver units, and the like. Using the user interface computer, software may then be utilized to calibrate and operate the system. Functionally, much of the operation of the EMT system 110 may be similar to that described in the aforementioned U.S. Pat. No. 7,239,731, U.S. Patent Application Publication No. 2012/0010493 A1 (U.S. patent application Ser. No. 13/173,078), and/or U.S. Patent Application Publication No. 2014/0276012 A1 (U.S. patent application Ser. No. 13/894,395), but various particular embodiments and features thereof may be described herein. Measurements are taken, a matrix of complex data is generated, and various algorithms are used to transform such data into tomographic images of the interior of the patient's head 19 .
[0121] Other embodiments of the present invention are likewise possible. In particular, EMT systems having components that are more easily transported than those of the system 110 described hereinabove are possible without departing from the scope of the present invention. In this regard, FIGS. 29 and 30 are a top front perspective view and a bottom rear perspective view, respectively, of another EMT system 210 for imaging a human head 19 in accordance with one or more preferred embodiments of the present invention. The system 210 includes an image chamber unit 231 , a control cabinet 235 , and a hydraulic system 240 for supplying, circulating, and otherwise managing a matching fluid to the image chamber unit 231 . The entire system 210 may be carried on a patient support 220 , which again may be a gurney, cart, table, stretcher, or the like. In particular, the image chamber unit 231 , which includes a built-in headrest 218 , is carried on a top surface of the patient support 220 , near one end, and the control cabinet 235 is carried beneath the patient support 220 . Such a system 210 may be more conveniently transported, and in particular, the system 210 may be rolled with the patient support 220 onto and off of an ambulance and into a medical facility. In this regard, FIG. 31 is a top plan view of the system 210 in use in an ambulance 211 .
[0122] In at least some embodiments, an image chamber unit of a type described herein is man-portable. As used herein, “man-portable” means cable of being carried or borne by one human. In particular, an image chamber unit of a type described herein may take the form of a wearable hat, helmet, cap, or the like. FIG. 32 is a side perspective view of a cap serving as a wearable image chamber unit in accordance with one or more preferred embodiments of the present invention. Aspects of such wearable apparatuses may be described, for example, in U.S. patent application Ser. No. 13/894,395.
[0123] At least some embodiments of the EMT systems presented herein, including without limitation the mobile embodiments such as the one presented in FIGS. 29-31 and the wearable cap of FIG. 32 , may be utilized advantageously outside of the clinical setting. FIG. 33 is a pictorial illustration of a timeline for use of an EMT system, including the cap of FIG. 32 , for imaging a human head in response to the onset of stroke symptoms in a patient. As shown therein, at 8:00 pm, a patient may be resting at home when he experiences the onset of stroke-like symptoms, such as disorientation and weakness in the face and arms. In response, he or a family member or friend contacts a medical provider, and an ambulance is dispatched. Meanwhile, a doctor or other medical practitioner is contacted and updated on the situation. The patient's head is placed in a mobile imaging unit, and scanning begins as shown around 8:25 pm. (In FIG. 33 , the mobile image chamber unit is the cap of FIG. 32 , but it will be appreciated that the unit of FIGS. 29-31 may be used instead.) Resulting data may be provided to the doctor, ambulance staff, imaging specialists, and other personnel. Some of the data may be used directly for diagnosis, treatment, or the like, while complex image-related data may be processed according to the systems and methods of the present invention to reconstruct images from which further diagnosis, treatment, or the like may be triggered. In at least some embodiments, such processing may generate an automatic alert that the data indicates that a potential stroke is likely. Notably, in at least some embodiments, such processing is carried out by a third party service provider who specializes in reconstruction of images according to the systems and methods of the present invention. During transport, from approximately 8:45 pm to 9:00 pm, the cap 331 continues to provide data regarding the patient's condition, and the local hospital staff is further updated and arranges and prepares for further treatment. Once the patient arrives at the hospital or other treatment center, the images and data may be used in providing timely, accurate information about the status of the stroke injury, and appropriate treatment and follow-up may be administered. Such a system could be utilized to provide the desired “under 3 hour” treatment that can make a major difference in the final outcome of the stroke injury and its affect on the patient.
[0124] It will be appreciated that in at least some embodiments, the systems, apparatuses and methods presented hereinabove may be incorporated into a 4D EMT differential (dynamic) fused imaging system. 4D EMT differential (dynamic) fused imaging system suitable for use with one or more preferred embodiments of the present invention are described in Appendix B.
[0125] Based on the foregoing information, it will 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 specifically described herein, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing descriptions thereof, without departing from the substance or scope of the present invention.
[0126] Accordingly, while the present invention has been described herein in detail in relation to one or more preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purpose of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended to be construed to limit the present invention or otherwise exclude any such other embodiments, adaptations, variations, modifications or equivalent arrangements; the present invention being limited only by the claims appended hereto and the equivalents thereof.
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An electromagnetic tomography system for gathering measurement data pertaining to a human head includes an image chamber unit, a control system, and a housing. The image chamber unit includes an antenna assembly defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber. The antennas include at least some transmitting antennas and some receiving antennas. The control system causes the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through a patient's head in the imaging chamber. A data tensor is produced that may be inversed to reconstruct a 3D distribution of dielectric properties within the head and to create an image. The housing at least partially contains the antenna assembly and has a front entry opening into the imaging chamber. The head is inserted horizontally through the front entry opening and into the imaging chamber.
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This application is a continuation of application Ser No. 07,683,736, filed Apr. 11, 1991 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a liquid crystal device for displaying information and to a method from producing such a device. More specifically, to a device having liquid crystal material stabilized by a support layer of material. In one embodiment, the support layer acts as a light shutter for information supplied underneath the liquid crystal support layer. For example, the liquid crystal material is coated on at least one side of a layer of absorptive material such as paper to dimensionally stabilize the thickness and uniformity of the liquid crystal material to provide an effective light shutter in the completed device. Examples of a liquid crystal device according to the present invention include a temperature sensitive label, a variable information display for example to be fixed substantially permanently on an instrument or part, and other types of fixed or variable information display devices.
2. Prior Art
Liquid crystal displays are in common use today such as on calculators, portable computers, office equipment including printers and copiers, etc. These displays are used on these devices for providing variable information to users such as numbers, letters, other indicia such as, sensing indicator displays and other types of information. Most of these common devices provide a variable information display by activating a layer of liquid crystal material by changing the electrical and/or magnetic field, or changing the temperature such as by heating specific points in the layer of liquid crystal.
Typically, in these prior art devices liquid crystal cells are implemented for the display. The liquid crystal cells are defined by structure for containing a layer of liquid crystal due to the liquid nature of this material. The container is necessary to provide a layer of liquid crystal of sufficient thickness to provide an effective display in combination with maintaining the thickness of the layer throughout the entire plane of the display. Improved liquid crystal cells are constructed by providing ground glass particles or beads of a specific layer thickness for maintaining a fixed distance between the plates of the cell during construction and use of the display.
Other displays provide uniform thickness liquid crystal layers by microencapsulating liquid material in a matrix such as plastic resin, which is cast or machined into a uniform layer. Still others devices appear to form a liquid crystal composition that includes chemical components to dimensionally stabilize the layer by changing the phase of the material to a solid.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to form a display device having a layer of liquid crystal stabilized by a support layer of material.
Another object of the present invention is to provide an improved liquid crystal display.
A further object of the present invention is to provide a liquid crystal display according to the present invention in the format of a label.
A still further object of the present invention is to provide a liquid crystal display having a support layer of absorptive material impregnated with liquid crystal material.
An even further object of the present invention is to provide a liquid crystal display having a support layer of absorptive material impregnated with liquid crystal material, which support layer becomes translucent upon being coated by the liquid crystal material.
An even still further object of the present invention is to provide a liquid crystal display having a support layer of material stabilizing a layer of liquid crystal material.
Another object of the present invention is to provide a method of making the liquid crystal display according to the present invention.
A further object of the present invention is to provide a method of making the liquid crystal display according to the present invention including coating a support layer of absorptive material on at least one side, preferably both sides, with liquid crystal material to form a light shutter, layering the support layer between a base layer and a covering layer, and providing information to be displayed on either the support layer or the base layer, or both.
A still further object of the present invention is to provide a method of making the liquid crystal display according to the present invention including coating a support layer on at least one side, preferably both sides, with liquid crystal material to form a light shutter, layering the support layer between a base layer and a covering layer, and providing information to be displayed on either the support layer and or base layer, or both.
These and other objects of the invention are accomplished by providing a display device having a support layer made of material capable of absorbing or binding liquid crystal material. The support layer is provided with liquid crystal material on at least one side, which contains or binds the liquid crystal material so as to make the layer of liquid crystal dimensionally stable in thickness and of sufficient thickness to perform as an effective light shutter. The support layer must dimensionally stabilize the liquid crystal layer in a manner so as not to interfere with the chemical properties, or only effect the chemical properties to a limited extent, so that the liquid crystal layer can function properly chemically in a specific display design by for example acting as a light shutter and/or changing color. Examples of support layers include various papers (including various cellulose based materials), felts and clothes or combination thereof that do not chemically react to the various liquid crystal materials. Further examples include composite layers of papers, felts or clothes in combination with synthetic materials (e.g. plastic) or layers to bind the liquid crystal within a matrix. The exact physical and chemical properties of the paper, cloth, felt or composite such as the sizing, weight, color, residual chemicals, layering, composition, fiber size, etc. can be controlled or selected to optimize the display characteristics of the device for a specific application.
Another important property of the support layer is its ability to transmit light therethrough. The support layer should be made of a material that is transparent or translucent, or one that becomes transparent or translucent upon the application of liquid crystal material, or upon other chemical or physical treatment. The support layer in the embodiment made of absorptive material may be totally saturated with the liquid crystal material with even a possible surface excess. Alternatively, only an amount of liquid crystal material is supplied during the coating operation so that it is totally absorbed in the support layer with no surface excess (i.e. unsaturated). As an example, an opaque layer of paper or cloth can be impregnated throughout its entire thickness to become translucent or essentially transparent to the information displayed during activation of the liquid crystal layer.
The support layer is layered on one side with a base layer of material. The base layer and/or support layer is provided with information to be displayed when the liquid crystal material is activated. Specifically, information can be deposited on or formed within these layers by various techniques such as printing with inks, thermal activation for example with laser beams or other known techniques of information imprinting or impregnation. The opposite side of the support layer is layered with a cover layer of material that is at least partially transparent or translucent so that the information provided on the base layer and/or support layer is displayed upon activation of the liquid crystal material.
The layer of liquid crystal material can be coated or applied by dipping or some other technique such as spraying onto the support layer. Further, the information can be developed or provided in or on the base layer by various techniques such as by printing including screen or mask printing, gravure printing, offset printing and lithographic-type printing.
The cover layer is provided to contain the liquid crystal material stabilized by the support layer, and to also provide a protective layer for the display. Preferably, the cover layer is a clear, colorless transparent material, for example, a layer of Mylar, polyethylene and polypropylene.
The base layer can be prepared or treated such as by providing a layer of adhesive, for example contact sensitive adhesive, on its outer side to form a sticky back label.
The base layer and/or the support layer depending on the design of the information displayed are made of materials selected so as to have the proper surface properties to enable information to be deposited thereon such as during a printing process. The surface roughness, ink affinity, porosity and other physical properties are selected for depositing a marking substance with good display characteristics. Also, the selection of the printing technique in combination with specific substrate material are selected to develop a good information display. For example, colored Mylar film provides a good base layer and low weight tracing paper provides a good support layer.
The display according to the present invention should be constructed to display information in a clear manner with high resolution to be effective as a display. Further, other quality factors of the finished display must be taken into consideration including the reflectivity of the cover layer, brightness of the information displayed. These factors can all be controlled by known printing methods and proper selection of the materials forming the base, support and cover layers based on the known properties of the materials selected.
It is important that the light shutter layer (i.e. support layer) substantially blocks out the transmittance of the display information when not activated. In order to assure essentially complete blockage, the light shutter layer must be made of sufficient and uniform thickness throughout its plane.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings, wherein like reference characters refer to like parts throughout the several views, and wherein:
FIG. 1 is a sequence diagram illustrating the operation of a display made according to the present invention;
FIG. 2 is a cross-sectional view of an embodiment of the display made according to the present invention;
FIG. 3 is a cross-sectional view of another embodiment of the display made according to the present invention;
FIG. 4 is a cross-sectional view of a label made according to the present invention; and
FIG. 5 is an illustration of an assembly line for producing the label shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is concerned with liquid crystal displays. The liquid crystal displays according to the present invention can be activated through any of the various known techniques such as changing the electronic field, magnetic field, or temperature at various points, regions, or the entire field within the layer containing the liquid crystal material. Further, the liquid crystal displays according to the present invention are particularly well suited for providing displays that utilize a layer of liquid crystal to act as a thermally activated light shutter. The present invention is particularly well suited for the production of labels wherein the light shutter is activated to transmit light or information (e.g. fixed information) when the layer of liquid crystal is heated.
The liquid crystal material utilized in the present invention are of type well known in the art. Specific formulations directly applicable for use in the present invention are discussed in U.S. Pat. No. 4,028,118, incorporated herein by reference.
The layer of liquid crystal is stabilized physically and/or chemically by a support layer. The support layer can be a layer of absorptive material that can absorb and/or bind the liquid crystal material, or alternatively, can be an adhering layer that binds and/or at least partially absorbs a layer of liquid crystal material. At least one of these layers is necessary to provide a sufficient thickness of liquid crystal material in a uniform thickness throughout its plane to function as an effective light shutter. Further, the support layer provides a liquid crystal layer with good mechanical characteristics such as tensile strength and can withstand mechanical manipulation during construction of the display. Also, the support layer provides a liquid crystal layer format that is easy to handle during construction of the displays.
Depending on the type of liquid crystal and the temperature, the support layer can contain what would otherwise be a layer of liquid, which by nature is relatively difficult to contain in an article, especially during assembly of a display. The support layer is very important in the high speed production of the displays by absorbing and/or binding the liquid crystal material, of a type in a liquid or solid phase, during the assembly stages of the display.
In FIG. 1, the sequence of operation of a liquid crystal display 10 made according to the present invention is shown. During the inactivate stage (left diagram), the display does not provide any information. Upon activation of the display (right diagram), such as by heating, the liquid crystal material associated with the support layer allows the transmittance of light and information 12 (e.g. "HOT"). The light shutter is deactivated upon cooling of the display again hiding the information. The display can be cycled through the display off/on stages an indefinite number of times.
A detailed cross section of an embodiment of the display 10 according to the present invention is shown in FIG. 2. The display in this embodiment comprises a base layer 14, a support layer 16 made of absorptive material, and a cover layer 18. The liquid crystal material utilized in this embodiment is contained within a support layer 16 made of the absorptive material. The liquid crystal material can be applied to the absorptive material layer 16 by coating at least one side of the absorptive material layer 16, or preferably both sides, during the method of making. The liquid crystal material may be partially absorbed into the absorptive material layer 16, or preferably is saturated therewith. Further, the absorptive material support layer 16 may also support a thin layer of liquid crystal material on one or both sides that is not fully absorbed into this layer. In any event, the absorptive support layer material 16 substantially stabilizes what essentially is a layer of liquid crystal material, which is in the liquid phase above a specific temperature.
The absorptive material layer 16 is made of a substance that can be clear, colorless, transparent, translucent or any combination thereof to a sufficient extent so that information can be transmitted through this layer upon activation of the liquid crystal material contained therein. For example, a paper or cloth can be utilized as the absorptive material layer 16. In order for this material to become translucent, it must be sufficiently saturated with the liquid crystal material. Alternatively, other materials, particularly fiber materials, capable of at least partially absorbing the liquid crystal material can be substituted therefore. However, these other fiber material must be transparent or translucent, or become transparent or translucent when covered or saturated with liquid crystal material (e.g. fiber glass roving or mat).
The support layer is preferably made of a material that can be made into the form of a web for the high speed production of making displays according to the present invention. Fibrous material are particularly well suited for this purpose since they can be formed into a web having sufficient tensile strength to prevent tearing and sufficient absorbency of the liquid crystal material. Papers, felts and clothes are the preferred materials for the making the support layer, since they are inexpensive, readily available in many grades and variety of specifications for different applications and purposes, and since these types of materials have the property of being opaque and becoming transparent or translucent upon absorbing liquid crystal material. Most preferred, are thin papers such as tracing paper or onion skin paper, since they become almost transparent upon absorbing liquid crystal material.
Further, the preferred support layer materials of paper, felt and cloth after being coated during an operation with hot liquid crystal material, become a wax-like solid (i.e. dry) when cooled to room temperature and provide an excellent stock material for handling purposes during the high speed production of displays, especially labels.
The information 12 is shown in FIG. 2 as being located on the lower surface of the support layer 16. For example, the rear of the support layer 14 can be reversed printed with information in the form of indicia. Alternatively or in combination, the base layer 14 may be provided with information to be displayed.
The base layer can be made of a material that may or may not absorb the ink from a printing operation. However, in the case of a non-absorptive surface, the ink can be stabilized in or on the surface of the base layer with various known techniques such as pretreating the surface by etching. Alternatively, the base layer can be made of a material that will readily absorb and fix the ink. However, in the case of an absorptive base layer, the outer surface should be treated, coated or laminated with a layer of material to form a liquid barrier to prevent the liquid crystal material from leaching or being absorbed through the base layer 14 to the outer surface of the display.
As an alternative embodiment, the information 12 can be printed on the outside surface of a transparent or translucent base layer 14, such as clear Mylar. Opaque material can also be used such as white or colored Mylar to enhance the visibility of the display.
Another embodiment of a display made according to the present invention is shown in FIG. 3. In this embodiment, the support layer 20 is made of adhering material. A liquid crystal layer 22 is applied to the adhering layer 20 for stabilization. The adhering layer 20 can be a fibrous material such as paper treated with a binder or adhesive having an affinity for liquid crystal, and which limits the absorbency of the fibrous material. This embodiment differs from the embodiment shown in FIG. 2, by stabilizing the liquid crystal material in a layer on the surface of the support layer 22 as opposed to stabilizing the liquid crystal material within the support layer 16. However, the extent of absorption and formation of a separate layer depends on such factors as the type of material and the manner of forming the material into a layer. Further, this embodiment is provided with a contact adhesive layer 23 to form a sticky back label.
The ends of the display should be sealed to prevent the flow of liquid crystal material therefrom. For example, as shown in FIG. 4, the ends 24,26 of the cover layer 18 and base layer 14, respectively, are sealed together by providing a clear adhesive layer 26 therebetween. This method of sealing the ends is particularly suitable for the high speed production of displays according to the present invention. This particular display arrangement is the end product of a method of making to be described below with the assembly line shown in FIG. 5.
An embodiment of a method of making a display according to the present invention is illustrated in FIG. 5. A roll 28 of stock material comprising a web 30 to form a base layer in the assembled display is supplied. For example, the stock material can be a colored or white Mylar film. A roll 32 of stock material comprising a web 34 of support material such as paper previously reverse printed, for example screen or flexo printed with indicia, on its rear surface and treated with liquid crystal material is supplied. Preferably, the printing operation is carried out prior to the liquid crystal coating operation. Further, preferably the paper web is coated on both sides with a hot liquid crystal composition. In a preferred process, the web 34 is handled at a temperature at which the liquid crystal is in a wax-like solid phase to ease handling, and prevent the flow of the liquid crystal material from the web (i.e. messing).
The side of the web 34 facing the web 30 is provided with a double sided type clear adhesive layer with a release liner for handling purposes. The remaining release liner is removed prior to bringing the webs 30 and 34 together. Alternatively, the web 30 is provided with the adhesive layer and release liner. A pair of pinching rollers 36 is provided for adhering the webs 30,34 together to produce a combined web 38. The combined web 38 is fed to a die cut roller station 40 where the web 34, only, is die cut into individual support layer sections 42 carried on the web 30. The waste portion 44 of the web 34 is stripped from the web 30 and formed into a roll 46.
A roll 48 comprising transparent web 50 of cover layer is supplied. The web 50 is laminated by heat and/or adhesive at the laminating station 52 to the web 30 carrying the support layer sections 42. The resulting composite web 54 is fed to a die cutting station 56 where the web 54 is cut into individual displays 10.
EXAMPLES
______________________________________Formulation A______________________________________160 grams Stearyl Alcohol (Manufactured by C. P. Hall)40 grams Polyethylene 9A (Manufactured by Allied Signal)15 grams Bis-Phenol A (Manufactured by Aristech Chemical) 5 grams Crystal Violet Lactone (Manufactured by Milton Davis)______________________________________
A 10-20 pound paper web is coated on both sides with formulation A. The web is blue in color below 50 degrees Celsius and becomes colorless and transparent above 50 degrees Celsius. This web is used in combination with a white colored Mylar web to produce labels as shown and described with respect to FIG. 5.
Example I
A white colored Mylar web is printed with bright orange colored ink to form the words "CAUTION HOT". The white colored web is laminated with the above-described blue web and the blue web is laminated with a clear Mylar web from which labels according to the present invention are formed therefrom and described above.
Example II
A white colored Mylar web is printed with the words "FOOD WARM". The label is used to indicate the time at which food or liquid in a package becomes warm in a microwave oven.
Example III
The crystal violet lactone in Formulation A is replaced by other dye(s) to produce virtually any color. At the transition temperature, the material becomes colorless.
Example IV
The stearyl alcohol in formulation A is replaced by other aliphatic alcohols to vary the transition temperature of the liquid crystal web between -10 to 70 degrees Celsius. The temperature range can be expanded further by varying the polymer (e.g. polyethylene) used in formulation A.
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A liquid crystal display and method of making. The display includes a layer of support material stabilizing a layer of liquid crystal material in dimensional thickness and uniformity. The invention is particularly well suit for making heat-sensitive display labels.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims the benefit of priority of Japanese Patent Application No. 2005-143934 filed on May 17, 2005, the disclosure of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to an imaging system for capturing an image in a vehicle.
BACKGROUND OF THE INVENTION
[0003] Conventionally, an imaging system or a camera disposed in a vehicle is used to capture an image in and out of the vehicle. That is, for example, the imaging system is used to capture an image of an intruder in the vehicle. Japanese patent document JP-A-2004-289625 discloses a car security apparatus, system and method that monitors the inside and outside of an automobile.
[0004] However, the camera suffers from tar of tobacco, chemical substance such as a cleaner solution or the like, and mucus from driver's body part adhered on a lens when the lens of the camera is always open to an atmosphere in the vehicle.
SUMMARY OF THE INVENTION
[0005] In view of the above-described and other problems, the present invention provides an imaging system that reduces opportunity for a lens of a camera in a vehicle to be exposed to an atmosphere in a vehicle.
[0006] The imaging system for use in a vehicle includes an imaging unit having a lens for imaging a state of affairs, and a rotation mechanism for defining a state of the lens of the imaging unit. The rotation mechanism is operated to be either in a first state or in a second state for defining the state of the lens, and the first position of the rotation mechanism arranges the lens in a state of separation from a room in the vehicle, while the second position of the rotation mechanism arranges the lens in a state of exposure to the room in the vehicle. In this manner, the camera is separated from the atmosphere in the vehicle for a decreased time. That is, the camera in the vehicle is retracted for protection from the exposure to the atmosphere and other substances when it is not in use.
[0007] Further, the first position of the rotation mechanism arranges the lens in a less obstructive state relative to a sight of a driver in the vehicle in comparison to the second position of the rotation mechanism. In this manner, the camera is more suitably arranged in the vehicle in terms of driving environment for a driver of the vehicle when the camera is not used for imaging.
[0008] Furthermore, the imaging system further includes an actuator for actuating the rotation mechanism and a controller for controlling the actuator. The actuator actuates the rotation mechanism to transit between the first position and the second position. The controller controls the actuator to cause the rotation mechanism to be in the first position when the vehicle is in use, and the controller controls the actuator to cause the rotation mechanism to be in the second position when the vehicle is not in use. In this manner, the lens of the camera suffers less from adhesion of tar of tobacco, chemical substances, human mucus or the like in the vehicle.
[0009] In this case, “the controller controls the actuator to cause the rotation mechanism to be in the first position when the vehicle is in use,” means that the actuator is controlled at least at one timing for the duration of vehicle operation including a timing of transition from non-operation to operation for causing the rotation mechanism to be put in the first position. Further, “the controller controls the actuator to cause the rotation mechanism to be in the second position when the vehicle is not in use,” means that the actuator is controlled at least at one timing for the duration of vehicle non-operation including a timing of transition from operation to non-operation for causing the rotation mechanism to be put in the second position.
[0010] For example, the imaging system may use an intrusion sensor for detecting an intrusion of a robber into the vehicle, and may control the actuator to cause the rotation mechanism to be put in the second state when the intrusion is detected by the detection sensor. In this manner, the camera is exposed to the atmosphere in the vehicle only in an occasion of intrusion, thereby making it difficult for the intruder to approach the vehicle from a dead angle of imaging or to turn away from the camera by using precaution.
[0011] The imaging system may have another sensor beside the camera for sensing a physical quantity that propagates in the room of the vehicle, and may switch the positions of a sensing portion of the another sensor between a third position that separates the sensing portion from the atmosphere in the room of the vehicle and a fourth position that exposes the sensing portion to the atmosphere in the room by using another actuator. In this manner, the actuator and the another actuator are controlled together for switching the rotation mechanisms between the first position in association with the third position and the second position in association with the fourth position. As a result, the camera and the another sensor have less time and opportunity to be exposed to the atmosphere in the room of the vehicle, and are put in an integrated control state.
[0012] The imaging system may have a flash for supporting imaging. In this case, the first position and the second position respectively correspond to an exposure state and an separation state of the camera and the flash to/from the atmosphere in the room of the vehicle. As a result, the flash has less time and opportunity to be exposed to the atmosphere in the room of the vehicle, and are put in an integrated control state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which:
[0014] FIG. 1 shows a perspective view of an imaging system for a vehicle in operation in an embodiment of the present invention;
[0015] FIG. 2 shows a perspective view of an imaging system for a vehicle not in operation in the embodiment of the present invention;
[0016] FIG. 3 shows a block diagram of the imaging system in the embodiment of the present invention;
[0017] FIG. 4 shows a side view of a console when a camera and a flash are retracted in a body of the console;
[0018] FIG. 5 shows a side view of the console when the camera and the flash are pulled out from the body of the console; and
[0019] FIG. 6 shows a flowchart of a program executed in a security ECU.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Embodiments of the present invention are described with reference to the drawings.
[0021] FIG. 1 shows a perspective view of an imaging system disposed in a vehicle in operation as an embodiment of the present invention. In FIG. 1 , the vehicle is in operation and under control of a driver who is authorized to control the vehicle. An overhead console 1 disposed above a room mirror 10 houses a movable portion 1 a of the imaging system embedded therein, and an instrument panel 2 has a movable portion 2 a of the imaging system embedded at an upper center surface of the panel 2 . A side pillar 3 has a movable portion 3 a of the imaging system embedded at a top of the pillar 3 .
[0022] The movable portions 1 a, 2 a, and 3 a are rotatably moved under control of the imaging system to be protruded from the overhead console 1 , from the instrument panel 2 , and from the side pillar 3 respectively when the vehicle is not in use as shown in FIG. 2 . The movable portion 1 a has, on a room facing side in a position protruded from the console 1 , a camera 11 capable of capturing a wide angle image or an all-round image accompanied by a flash 12 having LED or the like for imaging and lighting a view in the vehicle. The movable portion 2 b has, on the room facing side in a position protruded from the panel 2 , an infrared sensor 13 . The movable portion 3 b has, on the room facing side in a position protruded from the pillar 3 , a window sensor 14 for sensing breakage of windows.
[0023] The infrared sensor 13 has a infrared light emission unit and a infrared light reception unit for reflection of the infrared light. The emission unit and the reception unit are exposed toward the room in the vehicle for detecting an intruder into the vehicle as shown in FIG. 2 .
[0024] The window sensor 14 has a microphone exposed toward the room in the vehicle for detecting a sound of window breakage as an indication of break-in into the vehicle.
[0025] In this manner, the camera 11 , the flash 12 , the infrared sensor 13 , and the window sensor 14 are exposed toward the room in the vehicle by a rotation movement of the movable portions 1 a, 2 a and 3 a when the vehicle is not in use.
[0026] The control over the movable portions 1 a, 2 a and 3 a by the imaging system is described in detail in the following.
[0027] FIG. 3 shows a block diagram of the imaging system in the present embodiment of the invention. The diagram shows electrical connection between the components in the imaging system. The imaging system includes the camera 11 , the flash 12 , the infrared sensor 13 , the window sensor 14 , motors 15 , 16 , 17 , a door ECU 18 , an antenna 19 , and a security ECU 20 in addition to the movable portion 1 a, 2 a and 3 a.
[0028] The motor 15 is used to drive the movable portion 1 a under control of the security ECU 20 . The motor 16 is used to drive the movable portion 2 a under control of the security ECU 20 . The motor 17 is used to drive the movable portion 3 a under control of the security ECU 20 .
[0029] FIGS. 4 and 5 show side views of the console 1 for illustrating the movement of the movable portion 1 a. The lower right in FIGS. 4 and 5 is a direction of the room in the vehicle, that is, the direction of the front seats and back seats. The movable portion 1 a and the console 1 are movably connected around an axis, and the motor 15 drives the movable portion 1 a around the axis. That is, the movable portion 1 a is driven by the motor 15 to be in a position shown in FIG. 4 in an occasion, and is driven by the motor 15 to be in another position shown in FIG. 5 in another occasion. In this manner, a lens 11 a of the camera 11 and a light emission unit of the flash 12 are retracted in the console 1 for separation from the atmosphere in the vehicle by a rotational movement of the movable portion 1 a in an occasion, and are exposed to the atmosphere in the vehicle in another occasion.
[0030] The movable portion 2 a is driven by the motor 16 in the same manner as the movable portion 1 a. That is, the movable portion 2 a and the panel 2 are movably connected around an axis, and the motor 16 drives the movable portion 2 a around the axis. The movable portion 2 a is driven by the motor 16 to retract the light emission unit and the light reception unit of the infrared sensor 13 in the panel 2 for separation from the atmosphere in the vehicle in an occasion, and is also driven to exposed the emission/reception unit toward the room in the vehicle in another occasion.
[0031] The movable portion 3 a is driven by the motor 17 in the same manner as the movable portion 1 a. That is, the movable portion 3 a and the pillar 3 are movably connected around an axis, and the motor 17 drives the movable portion 3 a around the axis. The movable portion 3 a is driven by the motor 17 to retract the microphon of the window sensor 14 in the pillar 3 for separation from the atmosphere in the vehicle in an occasion, and is also driven to exposed the microphone toward the room in the vehicle in another occasion.
[0032] The door ECU 18 controls locking and unlocking of doors in the vehicle. For example, the door ECU 18 locks the door when it receives an authorized door lock request signal from a key-less entry terminal such as a smart key or the like carried by a user through the antenna 19 . The door ECU 18 unlocks the door when it receives an authorized door unlock request signal. The lock signal and the unlock signal may be a same signal or may be different signals. The door ECU 18 outputs a signal to the security ECU 20 when the door is locked and the door is unlocked.
[0033] The security ECU 20 includes a microcomputer of well-known type having a CPU, a RAM, a ROM and the like. The security ECU 20 also includes non-volatile memories such as a flash memory, a backup RAM, a hard disk drive or the like that maintains its content while a power supply from a vehicle power source is interrupted. The CPU executes a program stored in the ROM, reads and writes data from/to the RAM and/or the non-volatile memories, reads data from the ROM and exchanges signals with the camera 11 , the flash 12 , the infrared sensor 13 , the window sensor 14 , the motors 15 , 16 , 17 and the door ECU 18 .
[0034] FIG. 6 shows a flowchart of a program 100 repetitiously executed by the CPU. The CPU in the security ECU 20 execute a process of the program 100 in the following manner.
[0035] In step S 110 , the process determines whether the door is locked. The process determines locking of the door based on reception of a door lock signal from the door ECU 18 . The process proceeds to step S 120 when the door is locked, and repeats step S 110 when the door is not locked.
[0036] In step S 120 , the process controls the motors 16 , 17 for driving the movable portions 2 a, 3 a to expose the infrared sensor 13 and the window sensor 14 toward the room in the vehicle. In this manner, the light emission unit and the light reception unit of the sensor 13 as well as the microphone of the window sensor 14 are exposed as shown in FIG. 2 . In this case, the exposed infrared sensor 13 is in a position that obstructs a sight of the driver when the driver sits in a driver's seat. The exposed infrared sensor 13 is positioned to suitably detect a person in the vehicle.
[0037] In step S 130 , the process determines whether an intruder exists in the vehicle based on a signal from the infrared sensor 13 . The process proceeds to step S 140 when there is the intruder in the vehicle, and the process proceeds to step S 170 when there is no intruder in the vehicle.
[0038] In step S 140 , the process controls the motor 15 , and rotational movement of the movable portion 1 a exposes the camera 11 and the flash 12 . That is, the lens 11 a of the camera 11 and the light emission unit of the flash 12 are moved into the vehicle to be exposed. In this case, the exposed camera 11 and the flash 12 are in a position that obstructs a sight of the driver toward the room mirror 10 when the driver sits in a driver's seat. The exposed camera 11 and the flash 12 are positioned to suitably capture a view in the vehicle.
[0039] In step S 150 , the process controls the flash 12 to light the room in the vehicle, and also controls the camera 11 to capture an image of the room in the vehicle at the same time. In this manner, the camera 11 captures an image of the room in the vehicle which is lit by the light from the flash 12 , and the image is outputted to the security ECU 20 .
[0040] In step S 160 , the process controls the non-volatile memories to acquire and stored the image outputted from the camera 11 . In this case, the image may be sent through communication such as a radio transceiver (not shown in the figure) to an e-mail address of an owner of the vehicle or a security control center recorded in the non-volatile memories. Further, a horn of the vehicle or the like may be used to call attention to a condition of the vehicle.
[0041] In step S 170 , the process determines whether the door is unlocked based on reception of a door unlock signal from the door ECU 18 . The process proceeds to step S 180 when the door is unlocked, and the process returns to step S 130 when the door is not unlocked.
[0042] In step S 180 , the process controls the motor 15 to retract the movable portion 1 a having the camera 11 and the flash 12 into the overhead console 1 . In this manner, the lens 11 a of the camera 11 and a light emission unit of the flash 12 are retracted in the console 1 for separation from the atmosphere in the vehicle by a rotational movement of the movable portion 1 a as shown in FIG. 1 . Also in step S 180 , the process controls the motors 16 , 17 to drive the movable portions 2 a, 3 a to retract the infrared sensor 13 and the window sensor 14 into the instrument panel 2 and the side pillar 3 . In this manner, the light emission unit and the light reception unit of the infrared sensor 13 and the microphone of the window sensor 14 are retracted into the panel 2 or into the pillar 3 for separation from the room in the vehicle. The execution of the program concludes for the time after step S 160 or step S 180 .
[0043] In this manner, the security ECU 20 , under control of the program 100 executed in the CPU, exposes the infrared sensor 13 and the window sensor 14 in the room of the vehicle, detects the intruder, and captures an image of the room in the vehicle by the camera 11 and the flash 12 when the vehicle is not in use after locking the door. The captured image is stored in the non-volatile memories. Further, the security ECU 20 retracts the camera 11 with the flash 12 , the infrared sensor 13 and the window sensor 14 respectively into the overhead console 1 , the instrument panel 2 , and the side pillar 3 .
[0044] In this manner, the security ECU 20 controls exposure and separation of the camera 11 with the flash 12 , the infrared sensor 13 and the window sensor 14 to and from the room in the vehicle. That is, the lens 11 a of the camera 11 , the light emission unit of the flash 12 , the light emission unit and the light reception unit of the infrared sensor 13 and the microphone of the window sensor 14 are separated from the atmosphere in the room of the vehicle when the vehicle is in use, thereby reducing possibility of adhesion of tar of tobacco, chemical substances such as a cleaner, or mucus from driver's body part onto the lens 11 a, other units or the like. Further, the driver has a better view when the vehicle is in use, because the camera 11 , the sensor 13 are retracted.
[0045] Furthermore, the camera 11 is exposed at a timing when the infrared sensor 13 detects the intrusion of the intruder into the room of the vehicle, thereby making it difficult for the intruder to approach the vehicle from a dead angle of imaging or to turn away from the camera by using precaution.
[0046] Furthermore, the security ECU 20 executes another process for calling attention to the vehicle by sending e-mails through a communication device not shown in the figure to addresses of a security center and/or an owner of the vehicle stored in the ROM or the non-volatile memory upon detecting a glass breakage sound by the window sensor 14 when the vehicle is not in use, in parallel with the process of the program 100 . In addition, the horn of the vehicle or the like is used to make a warning sound.
[0047] Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.
[0048] For example, the security ECU 20 may expose the camera 11 with the flash 12 in addition to the infrared sensor 13 with the windows sensor 14 to the room at the same time when the door of the vehicle is locked.
[0049] Further, the camera 11 may be disposed on the upper center portion of the instrument panel 2 , or on the side pillar 3 or another pillar. The camera 11 may also be disposed on a ceiling of the room in the vehicle. For example, the camera 11 disposed in a concave portion of the ceiling in the vehicle may be covered from the atmosphere in the room by covering the concave portion in the first state, and may be exposed to the room in the second state by sliding off a covering of the concave portion.
[0050] Furthermore, the security ECU 20 may be a dedicated processor for executing a process that is identical to the process performed by execution of the program 100 .
[0051] Furthermore, the use of the vehicle may be determined based on turning on/off of the main power source of the vehicle (IG, ACC etc.) instead of based on locking/unlocking the door of the vehicle.
[0052] Furthermore, the movable portions 1 a, 2 a, 3 a may be driven based on an input from a user operation instead of based on the use/non-use of the vehicle. That is, the camera 11 , the flash 12 , the infrared sensor 13 and the window sensor 14 may be exposed to the room by driving the movable portions 1 a, 2 a, 3 a, and may be separated from the room by reversing the movement of the movable portions 1 a, 2 a, 3 a upon receiving the an input from the user respectively.
[0053] Furthermore, the movable portions 1 a, 2 a, 3 a may be driven by a user's hand instead of a motor. That is, the camera 11 and other units on the movable portions 1 a, 2 a, 3 a may be opened by the user's hand when the user enters into the vehicle, and may be retracted by the user's hand when the user comes out of the vehicle.
[0054] Furthermore, the infrared sensor 13 may be replaced by an ultrasonic sensor, a radio wave sensor or the like, as long as it detects the intrusion of the intruder into the vehicle.
[0055] Furthermore, the infrared sensor 13 and the window sensor 14 may be replaced by any sensor that receives propagation of physical quantity in the room of the vehicle.
[0056] Furthermore, the lens 11 a, the light reception unit and the light emission unit may be at least partially covered or separated in the room in the first state in comparison with the second state. In this manner, the lens 11 a and other units may be less susceptible to tar and other foreign matter adhered thereon.
[0057] Furthermore, the camera 11 may capture a view from the vehicle. For example, the camera 11 may capture a front view of the vehicle. In this case, the movable portions 1 a, 2 a, 3 a may be opened in the first state when the vehicle is not in use by controlling the driving mechanisms, and may be retracted in the second state when the vehicle is in use by controlling the driving mechanisms.
[0058] Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.
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An imaging system for use in a vehicle includes an imaging unit having a lens for imaging a state of affairs and a rotation mechanism for defining a state of the lens of the imaging unit. The rotation mechanism is operated to be either in a first position or in a second position. That is, the first position of the rotation mechanism arranges the lens in a state of separation from a room in the vehicle, and the second position of the rotation mechanism arranges the lens in a state of exposure to the room in the vehicle.
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[0001] This application is directed to a method and apparatus for transporting metal objects. This application claims priority in Provisional Patent Application Ser. No. 60/985,434 that was filed on Nov. 5, 2007 which is incorporated by reference herein.
[0002] The present invention relates to transporting metal objects and more particularly to a method and apparatus for transporting steel billets from a randomly oriented condition in a staging area to a conveying system for further processing of the billets.
INCORPORATION BY REFERENCE
[0003] Metal billets and other elongated metal objects can be used for a wide range of manufacturing processes. This requires that these billets be moved or transported through the manufacturing processes from when they are formed to when they are processed to produce other products. As can be appreciated, movement of these billets, or elongated objects, from a storage area to a processing phase of a facility can be accomplished by many means. As with other manufacturing processes, robots can be used for the transportation of objects. U.S. Pat. No. 3,587,872 discloses a mechanical arm and control means therefor that can be used to pick and place objects wherein this patent is incorporated by reference herein as background material showing same. U.S. Pat. No. 4,283,165 discloses a motorized manipulator having a robotic arm configuration which is incorporated by reference herein as background material showing the same. U.S. Pat. No. 4,698,775 discloses a self-contained mobile reprogrammable automation device which is also incorporated by reference herein as background material relating to devices used to move objects. U.S. Pat. No. 4,501,522 discloses a manipulator that can be used to transport objects wherein this patent is also incorporated by reference herein as background material. U.S. Patent Publication No. 2006/0157476 discloses an apparatus and method for induction heating a piece of electrically conductive material which is incorporated by reference herein for showing the same. U.S. Pat. No. 4,806,066 which discloses a robotic arm that includes opposed grippers which is incorporated by reference herein as background material showing the same. U.S. Pat. No. 6,626,630 discloses a Cartesian robot which is a linear style actuator which is also incorporated by reference herein as background material showing the same.
BACKGROUND OF THE INVENTION
[0004] Billets and other elongated objects have been used in manufacturing for many years wherein these objects must be moved or transported from one process to the next, stored, removed from storage and even manipulated or orientated for certain operations between the creation of the billet and the final processing of the billet. In the past, many methods have been used to transport or move these objects which include manual movement, vibratory feeders, conveyors, bins and pushers. These devices can be utilized to move or transport the billets from a first position to a second position.
[0005] As can be appreciated, the location and orientation of the billet must be known before the billet can be moved from the first position to a second or known position. Further, interengagement with a desired number of billets at the first position, when the billet is in a randomly oriented condition, requires either manual manipulation by an operator or the use of sensors or other vision-type features on the movement device to properly orient the device. In this respect, and with respect to traditional jaws or grippers utilized in pick and place style manipulators, the device must know the orientation of the billet to properly align the jaws of the movement device with respect to the billet such that the jaws can grasp the billet. Once the billet is grasped, it can be manipulated as is needed for the particular operation. Not only does the movement device need to sense the position of the billet, it also must be able to articulate the jaws to properly orient the jaws relative to the billet to grasp the billet. As can be appreciated, this articulation can require multi-axis equipment so that the jaws can be oriented relative to the billet. The need for both vision and multi-axis articulation can greatly increase the costs of the device and can also greatly reduce the reliability and longevity of the device. This is especially true in the harsh environment typically associated with billet processing
STATEMENT OF INVENTION
[0006] In accordance with the present invention, a system to feed an elongated metallic workpiece to a manufacturing process is provided wherein this system includes an automatically orienting gripping mechanism to interengage with a randomly oriented elongated object, such as a metallic billet, and a movement device that transports the object to a subsequent processing point such as to a conveying system that can be used to feed subsequent operations.
[0007] In this respect, in one embodiment, provided is a system to feed elongated metallic workpieces to a manufacturing process wherein the elongated workpieces have a workpiece body extending along a workpiece axis between a first workpiece end and a second workpiece end. The system includes a storage hopper configured to hold a plurality of the workpieces that are randomly oriented and a movement device. The movement device includes a frame and a workpiece support joined to the frame wherein the workpiece support is moveable between a load position proximate the hopper and an unload position away from the load position. This workpiece support further includes an engaging surface and a flexible extension joining the engaging surface to the frame thereby allowing the engaging surface to move relative to the frame and a means for selectively producing an attractive force between the engaging surface and a workpiece to direct the engaging surface to a desired number of the workpieces regardless of the position of the workpieces when the engaging surface is in the load position. The attractive force means can selectively secure the desired number of workpieces relative to the engaging surface in the load position and release it in the unload position.
[0008] According to another aspect of the present invention, the system can further include a self-alignment apparatus to generally align the workpiece axis of the desired workpiece relative to the conveyor axis near the unload position.
[0009] According to a further aspect of the present invention, the system can include a conveyor at the unload position wherein the conveyor has a first conveyor end and a second conveyor end with a drive line moving along a driveline axis from the first conveyor end to the second conveyor end such that the second conveyor end directs the workpieces into a process and the unload position is over the conveyor.
[0010] According to another aspect of the present invention, the system can be configured to secure a single workpiece and in another embodiment two workpieces.
[0011] According to a further aspect of the present invention, the movement device can be a robotic arm.
[0012] According to yet a further aspect of the present invention, the movement device can be a linear actuator.
[0013] According to a further aspect of the present invention, the manufacturing process is an induction heating process.
[0014] According to another aspect of the present invention, the self-alignment feature is a pair of angled baffles positioned on either side of the drive line at the unload position.
[0015] According to yet a further aspect of the present invention, the pair of angled baffles is adjustable transverse to the conveyor axis to accommodate different size workpieces.
[0016] According to a further aspect of the present invention, the attractive force includes magnetic.
[0017] According to another aspect of the present invention, the attractive force includes a vacuum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The foregoing, and more, will in part be obvious and in part be pointed out more fully hereinafter in conjunction with a written description of preferred embodiments of the present invention illustrated in the accompanying drawings in which:
[0019] FIG. 1A is a elevated layout view of a manufacturing operation including an embodiment of a system for transporting elongated objects according to the present invention wherein the system is shown in a load position;
[0020] FIG. 1B is the elevated layout view of FIG. 1A wherein the system is shown in an unload position;
[0021] FIG. 2 is a perspective view of the movement device as is shown in FIG. 1 ;
[0022] FIG. 3 is an enlarged perspective view of a workpiece support including multiple engaging components;
[0023] FIG. 3A is a sectional view taken along lines 3 A- 3 A in FIG. 3 ;
[0024] FIG. 4 is an enlarged perspective view of a workpiece support including a single engaging component;
[0025] FIG. 4A is a sectional view taken along lines 4 A- 4 A in FIG. 4 ;
[0026] FIG. 5 is a perspective view of another embodiment of the present which includes an orientation device at least partially spaced from the unload position shown in FIG. 1B ;
[0027] FIG. 6 is an enlarged perspective view of a workpiece support according to another aspect of the present invention which includes powered rotation;
[0028] FIG. 7 is a partially sectioned elevational view showing a workpiece support in relation to a conveying system above the unload position;
[0029] FIG. 8 is a partially sectioned elevational view showing the workpiece support in relation to a conveying system in the unload position;
[0030] FIG. 9 is a sectional view taken generally along lines 9 - 9 ; and
[0031] FIG. 10 is partially sectioned elevational view showing the workpiece support in relation to a conveying system in the unload position showing a workpiece having a different cross sectional configuration.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] Referring now in greater detail to the drawings wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting the invention, FIGS. 1A and 1B show a manufacturing operation or system 10 that includes a storage hopper 20 and a manufacturing process 30 with a conveying system 40 capable of feeding a workpiece W into manufacturing process 30 . As can be appreciated, the manufacturing process can be a wide range of manufacturing processes including, but not limited to, a heating process to heat workpiece W. This heating process can be an induction heater and workpiece W can be a metal billet. However, the invention of this application should not be limited to the induction heating of metal billets.
[0033] Manufacturing operation 10 further includes a movement device 50 configured to feed workpiece W to conveying system 40 . In this respect, movement device 50 is configured to move a workpiece between a load position 60 ( FIG. 1A ) and an unload position 62 ( FIG. 1B ). The movement device can be any one of a number of motion devices including, but not limited to, pick and place devices, robotic arms, linear drives, and/or rotational drives configured to move a workpiece support 70 to position 60 such that the workpiece support can engage one or more workpieces W in hopper 20 , to remove the workpiece from hopper 20 and to move the workpiece towards position 62 wherein the workpiece can be deposited on conveying system 40 . As a result, the workpieces in hopper 20 can be controllably moved from the hopper to the conveyor such that workpiece W can be conveyed into a manufacturing operation.
[0034] As is discussed above, manufacturing operation 30 can be any one of a number of operations or multiple operations including an induction heating operation used to heat a metal billet for further processing in the manufacturing facility. Since the invention of this application has been found to work particularly well in connection with metal billets and induction heating, it is being described herein in connection with this application. However, as can be appreciated, the invention of this application is broader in its application.
[0035] Hopper 20 can be any storage device used in manufacturing or other applications including a reusable containers and/or a disposable container 72 . Further, storage hopper 20 can be a fixed hopper positioned on a surface such as the floor or a moving hopper wherein the storage hopper is, for example, rolled into position on a separate conveyor system, not shown. As can be appreciated, either style storage hopper can include the use of a disposable cardboard container mounted to a packing skid 74 such that a forklift can position a full hopper and remove an empty hopper as is needed. Whether a movable or a stationary hopper is utilized, the hopper can include a tilting feature 76 to at least partially tilt the hopper for aiding in the positioning of the workpieces in the hopper when, for example, only a few workpieces are remaining in the hopper.
[0036] As can be appreciated, the size and configuration of the storage hopper can vary greatly depending on the size of the workpiece and the production rate of the facility. As will be discussed in greater detail below, these differing sizes and configurations can impact the configuration of the workpiece support.
[0037] With reference to FIGS. 1-6 , movement device 50 is configured to move the workpiece support between load position 60 and unload position 62 such that the workpieces can be controllably transported from a storage condition to a processing condition regardless of the orientation of the workpiece in the hopper. Holder 70 accomplishes this by being configured to controllably secure and release one or more workpieces and; further, to engage a desired number of the workpieces for each cycle of the system from the load to the unload position automatically. Yet even further, this automatic engagement of the desired number of workpieces is achieved without manual manipulation, vision, sensors or powered actuation relative to the movement device. This allows movement device 50 to be a simple and reliable device and further simplifies the corresponding control or operating system such that costs are reduced and, repeatability and reliability are increased.
[0038] In one embodiment, movement device 50 is a multi-axis robot having a support pedestal 100 with rotating base 102 secured to pedestal 100 . Device 50 further includes a first arm 104 joined to base 102 by a first pivot connector 106 . Device 50 can further include a second arm 110 pivotally joined to arm 104 at a second pivot joint 112 . By including second arm 110 , the range and mobility of device 50 can be increased. Further, second arm 110 helps allow workpiece holder 70 to enter into hopper 20 .
[0039] Workpiece holder 70 is joined to arm 110 and can also be joined by a pivoting or articulating joint such as a workpiece joint 120 . By including joint 120 , the range of motion of holder 70 is further increased.
[0040] The movement device is controlled by an operating system 130 that controls the desired movement of the movement device. In addition, operating system 130 can also be configured to operate one or more other devices in system 10 . Operating system 130 can be any operating system known in the art including, but not limited to, a computer operating system.
[0041] In one embodiment, holder 70 includes a workpiece arm 150 joined at a first end 152 to joint 120 such that arm 150 extends to a distal end 154 . Arm 150 can be a rigid member as is shown in at least one embodiment of this application. However, is will be discussed in greater detail below, arm 150 also can be a flexible member.
[0042] With special reference to FIGS. 3 and 3A , shown is a workpiece support configuration 70 B wherein the workpiece support includes a quick change hanger arrangement 160 that can be used to quickly reconfigure system 10 according to the parameters of the manufacturing operation. In this respect, hanger 160 can be used in combination with quick change lock blocks 168 to change the number of engagement members, the spacing between the members, the length of the members etc. which can be modified based on the hopper configuration and/or the workpiece configuration which will also be discussed in greater detail below. Hanger 160 and lock blocks 168 can use any quick change technology known in the art without detracting from the invention of this application.
[0043] Workpiece holder 70 B is configured to engage two workpieces. Hanger 160 is joined to arm 150 by a flexible member 162 which can be used to increase the range of motion of the workpiece holder. Flexible members 164 and 166 extend between blocks 168 and the respective engagement members 174 and 176 wherein the length of members 164 and 166 can also be used to control the range of motion of holder 70 B. Engagement members 174 and 176 further include attraction and support devices 180 and 182 wherein members are spaced such that holder 70 B is configured to engage a single workpiece. As is discussed throughout this application, engagement devices 180 and 182 can include a wide range of technologies used to locate and support (attract) randomly oriented workpieces. This includes permanent magnets, electro-magnets and other magnetic technologies, a vacuum, or any other method of attracting another object.
[0044] Engagement devices 180 , 182 in this embodiment are electro-magnets positioned at or near engagement surfaces 184 and 186 , respectively, wherein these magnets are joined to operating system 130 by leads 170 and 172 which control when the electro-magnets are on and/or off. Since members 174 and 176 magnetically engage metal workpiece W, the members selectively secure themselves to the workpieces automatically based on attractive forces alone along with the movement device moving the holder within range of the workpieces.
[0045] In order to ensure that each engagement member 174 and 176 picks only a single workpiece, spacing D 1 between flexible members 164 and 166 and length D 2 of flexible members 164 and 166 can be configured such that each engagement device is not capable of engaging the same elongated object. As can be appreciated, spacing D 1 and length D 2 is based on the configuration and size of the workpiece.
[0046] In yet another embodiment of the invention of this application, components 180 and 182 can be permanent magnets wherein these magnets are joined to a linear actuator such that they move relative to surfaces 184 and 186 , respectively. As these permanent magnets move away from engagement surfaces, the magnets loose their effect and the members are then in the “off” condition. Conversely, when the permanent magnets are in a position proximate to the corresponding engagement surface, the member is in the “on” condition. As with the other embodiments in this application, the permanent magnets can also be controlled by operating system 130 .
[0047] In any embodiment in this application, some or all of the remaining components can be made from non-magnetizable materials to help prevent unwanted magnetization of these other components thereby preventing unwanted attractive forces.
[0048] By utilizing magnets in combination with flexible members 162 , 164 and 166 , engagement devices 174 and 176 can automatically locate a respective billet without the need for sensors and/or vision components in movement device 50 . As can be appreciated, the size of storage hopper 20 will, at least in part, dictate the amount of motion that is necessary to allow engagement devices 174 and 176 to find a workpiece within the hopper. Further, tilting device 76 can be used in connection with hopper 20 to minimize the range of motion necessary to direct the engagement members to the workpieces within the hopper. For example, larger hoppers could necessitate the need for longer flexible devices. As a result of this system, the engagement devices can be simply lowered into the hopper and then automatically engage a workpiece from a randomly oriented pile of workpieces.
[0049] In yet another embodiment of the invention of this application, movement device 50 can include a simple sensor in communication with operating system 130 to let the operating system know that a workpiece has been engaged and secured.
[0050] With reference to FIGS. 4 and 4A , workpiece support 70 C is shown. This embodiment includes hanger 160 and lock blocks 168 to allow for quick changeovers. Again, workpiece W is shown which is an elongated member having a circular cross-sectional configuration. In this embodiment, engagement member 200 includes a shaped engaging surface 202 configured to matingly engage with the outer cylindrical surface of workpiece W. As with the embodiments discussed above, workpiece support 70 C includes flexible member 162 and can further include a flexible member 163 configured to allow engagement member 200 to adequately move within the storage hopper to engage a workpiece. This particular configuration is designed to engage a single workpiece. However, more than one engagement member 200 could be mounted to hanger 160 without detracting from the invention of this application. Further, engagement member 200 can includes a centrally located magnet 208 proximate to surface 202 to magnetically engage the workpiece when in load position 60 . As with the other embodiment in this application, magnet 208 can be an electro-magnet connected to operating system 130 by way of electrical connection 210 or an actuated permanent magnet, vacuum or any other attractive force technology.
[0051] With reference to FIGS. 7-10 , even a randomly oriented workpiece retrieved from hopper 20 can be oriented properly on conveyor system 40 . In one embodiment, conveyor system 40 can include angled baffles 250 and 252 that are spaced from one another on either side of conveyor belt 254 . This conveyor system can be any known conveyor system and, therefore, it will not be discussed in greater detail in this application. Angled baffles 250 and 252 can be joined to conveyor 40 by way of adjustable brackets 260 wherein brackets 260 can include elongated slot 262 which can be used in connection with a fastener 264 to modify spacing S between the baffles based on the size of workpiece W. As workpiece W is lowered toward belt 254 , baffles 250 and 252 , in combination with flexible members 162 , 164 and 166 , align workpiece W such that it is generally parallel to edges 270 and 272 of belt 254 when it reaches the belt. In yet another embodiment, baffles 250 and 252 can be powered baffles connected to a linear actuation device (not shown) to allow quick adjustments to be made to spacing S. This powered system can also be connected to operating system 130 .
[0052] With reference to FIG. 6 , workpiece holder 70 D is shown. This embodiment does not include a hanger assembly. Conversely holder 70 D includes a single engagement member 200 connected to a flexible member 222 which is joined directly to workpiece joint 120 . This embodiments can function similar to those discussed above; however, it further a rotational device 230 that can further help orient the workpiece holder and/or the workpiece during any point of the process. Further, rotational device 230 can be either a powered rotational device and/or a freely rotating device which can be used to help orientation. Yet even further, rotational device 230 can include a locked and an unlocked condition. Again, these features will be discussed in greater detail below.
[0053] With respect to loading the workpiece, when the workpiece support is in load position 60 , rotational device 230 can be in an unlocked condition to allow the full and free movement of the engagement device relative to the movement device to help the alignment between the engagement member and the workpiece. Then, the rotational device can be mechanically moved to a set position to properly orient the workpiece relative to the conveyor belt before it reaches the conveyor. This arrangement is best suited for the workpiece support that includes a shaped engagement surface as is shown in FIG. 6 .
[0054] With reference to FIG. 5 , the alignment or baffle structure can be spaced from the unload position. In this respect, shown is an alignment shoot 300 that can be positioned between load position 60 and unload position 62 and can include multiple alignment surfaces such as surfaces 302 , 304 , 306 and 308 . As workpiece W is moved through alignment device 300 by the motion produced by movement device 50 , one or more of the surfaces of workpiece W engage one or more surfaces 302 , 304 , 306 and 308 which then begin to orient the workpiece relative to these known surfaces. This can be done in combination with selectively rotatable rotation device 230 or the other flexible members discussed above to align the workpiece.
[0055] In one embodiment, as workpiece W enters engagement device 300 , rotational device 230 can be unlocked to allow the free rotation of the workpiece relative to the alignment device. Then, once the workpiece is aligned, rotational device 230 can be locked. In addition, the flexibility of the flexible members could also be locked in yet another embodiment. As a result of this alignment feature, the orientation of the workpiece relative to the movement device would be known after the workpiece passes through the orientation device such that it can be positioned on the conveyor system without further orientation.
[0056] In yet even a further embodiment, rotational device 230 can provide, at least in part, the free rotational movement necessary to help align the workpiece with the conveying system as the workpiece engages baffles 250 and 252 .
[0057] As is shown in FIG. 9 , the invention of this application can be used with other workpiece configurations without significant modification. In this embodiment, angle baffles 250 and 252 are adjusted based on the size and shape of workpiece W 2 wherein the square cross-sectional configuration of workpiece W 2 can be properly oriented to the conveyor.
[0058] In yet another embodiment of the invention of this application, the strength of the magnet used in connection with any one of the work holders can be configured to only support a single billet which can also be used to ensure that only the desired number of workpieces is engaged by the workpiece holder in the load position.
[0059] While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments and/or equivalents thereof can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
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An apparatus to feed elongated metallic workpieces to a manufacturing process including a storage hopper configured to hold a plurality of workpieces that are randomly oriented and a movement device having a workpiece support that is automatically engageable with a workpiece.
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TECHNICAL FIELD
[0001] The present invention relates generally to a shield for use in processing reactive metals in an inert gas environment. More particularly, this invention is directed to a shield which can be used in conjunction with operations utilizing high-power-density processes such as lasers and out-of-vacuum electron beams or arc-assisted processes such a GMAW, GTAW and plasma welding and/or cladding systems.
BACKGROUND
[0002] In most welding, surfacing and cladding operations wherein sufficient heat is applied for melting metal alloys, it is essential to shield the thermally excited regions with specially formulated gases. Reactive metals (i.e., titanium, zirconium, and hafnium) at elevated temperatures have high solubilities for oxygen, nitrogen, and hydrogen. The dissolution of relatively small amounts of these gases into the metal significantly affects the metal's physical properties. For example, the dissolution of oxygen and nitrogen significantly increase hardness while the dissolution of hydrogen reduces toughness and increases notch sensitivity.
[0003] Oxygen, nitrogen, and hydrogen are all present in the atmosphere. Therefore, when welding reactive metals it is important to shield from the atmosphere that portion of the reactive metal that would be at elevated temperatures (i.e., molten weld pool, hot solidified weld metal, and adjacent heat-affected zone). The shielding is normally accomplished by surrounding the area to be protected by a nonreactive gas such as argon or helium.
[0004] In the case of arc processes, proper selection of shielding gas based on its ionization potential, density, thermal conductivity and chemical reactivity with the molten and solidified alloys, and controlled introduction of the selected gas about the welding region, that is, the arc and molten pool, ensure stable arc behavior, and volumetrically sound and dimensionally consistent deposits with proper composition. This minimizes alloy loss due to oxidation. Similarly, many laser-assisted welding, surfacing and cladding operations are affected by the gas shielding quality.
[0005] The shielding of the molten weld pool is conventionally provided by a torch shield. The torch shield is disposed at the terminus of the welding torch and consists of a cup open at one end through which an electrode protrudes. This shield advances in the direction of the welding and therefore does not shield either the solidified weld metal or the adjacent heat-affected zone. In order to protect this area, a trailing shield is employed. Many conventional trailing shields consist of a rigid housing that is mounted to the welding torch and configured to provide effective shielding to a predetermined surface configuration.
[0006] Various problems exist with rigidly constructed trailing shields. For example, if the surface configuration changes or another workpiece of different configuration is to be welded, the trailing shield would have to be replaced with one adapted to the particular surface configuration. Similarly, if no trailing shield is available for a particular surface configuration, less than adequate shielding will be provided.
[0007] U.S. Pat. No. 4,599,505 discloses a trailing shield for providing nonreactive gas shielding to a welding operation, the shield comprising a housing formed of interlocking transverse segments and purportedly “capable of flexibly covering weld surfaces having varying configurations” (col. 1, lines 34-37).
[0008] There is a need for a shield capable of maintaining an inert gas envelope around the top of a workpiece having a contour with sharp turns, such as airframe components.
SUMMARY OF THE INVENTION
[0009] The present invention is a self-adjusting trailing shield for maintaining a volume of inert gas over a portion of a metal workpiece being subjected to a metal processing operation. The shield has a pair of side walls, each side wall comprising a fixed portion and a segmented portion, each segment being independently vertically displaceable relative to the fixed portion as the shield is carried in a horizontal plane across a contoured surface of a workpiece. Each segment will be forced upward when it contacts and slides up a rising surface portion of the workpiece. Each segment is coupled to a respective compression spring that restores each deflected segment to its original, i.e., fully extended, position as the segment slides down a falling surface. The result is a continual reconfiguration of the segmented portions of the side walls that reduces the amount of inert gas escaping from the cover space during travel of the shield, as compared to a shield having rigid side walls without vertically displaceable segments.
[0010] One aspect of the invention is a shielding apparatus for metal processing operations comprising: a base comprising an opening and first and second sides; a first plurality of segments arranged side by side in a row along the first side of the base; and a second plurality of segments arranged side by side in a row along the second side of the base, wherein each of the segments is independently displaceable in a direction that is generally transverse to the base and between extended and retracted positions, the segments and the base forming a tunnel when the segments are all in their extended positions.
[0011] Another aspect of the invention is an apparatus for metal processing operations comprising: means for directing energy toward a metal workpiece to raise the temperature of a portion of the surface of the workpiece; a shielding apparatus attached to the energy directing means; and means for supplying pressurized inert gas to the shielding apparatus, wherein the shielding apparatus comprises: a base attached to the energy directing means; a first plurality of segments arranged side by side in a row along a first side of the base; and a second plurality of segments arranged side by side in a row along a second side of the base, wherein each of the segments is independently displaceable in a direction that is generally transverse to the base and between extended and retracted positions, the segments and the base forming a tunnel when the segments are all in their extended positions, the tunnel being in fluid communication with the inert gas supplying means.
[0012] A further aspect of the invention is a shielding apparatus for metal processing operations comprising: a base comprising an opening; a plurality of segments arranged side by side to form a barrier, wherein each of the segments is independently displaceable in a direction that is generally transverse to the base and between extended and retracted positions; a multiplicity of guiding means supported by the base, each of the guiding means guiding a respective one of the segments along the direction of displacement; and a multiplicity of springs supported by the base, each of the springs urging a respective segment toward its extended position.
[0013] Yet another aspect of the invention is a method of manufacturing an aircraft component having a contoured surface, comprising the following steps: subjecting portions of a workpiece to a metal processing operation; moving a gas shield having an interior space over portions of the workpiece to be subjected to the metal processing operation, the interior space being bounded in part by a plurality of vertically displaceable wall segments; supplying inert gas into the interior space of the gas shield during movement of the gas shield; and maintaining a volume of inert gas over any portion of the workpiece to be subjected to the metal processing operation, wherein said maintaining step comprises the step of displacing the wall segments vertically to compensate for changing elevation of the surface of those portions of the workpiece to be subjected to the metal processing operation.
[0014] Other aspects of the invention are disclosed and claimed below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic showing a side view of a gas shield in accordance with one embodiment of the invention.
[0016] FIG. 2 is a schematic showing an isometric view of the gas shield of FIG. 1 in an upside-down position.
[0017] FIG. 3 is a schematic showing an isometric view of the gas shield of FIG. 1 from a vantage point forward of the leading wall of the shield.
[0018] FIG. 4 is a schematic showing a front view of a subassembly of the gas shield in accordance with the disclosed embodiments of the invention. Only one of multiple vertically displaceable gas shield slide segments is shown mounted to a side plate.
[0019] FIG. 5 is a schematic showing an end view of the subassembly depicted in FIG. 4 without the vertically displaceable gas shield slide segment.
[0020] FIG. 6 is a schematic showing a cross-sectional view of a side wall of the shield depicted in FIG. 1 , the section line being taken along line 6 - 6 seen in FIG. 1 .
[0021] FIG. 7 is a schematic showing a side view, on an enlarged scale, of a leading portion of the shield as seen in FIG. 1 , which leading portion incorporates a vertically displaceable subassembly that includes a front gas shield slide door and a roller bearing designed to roll on a surface of a workpiece.
[0022] FIG. 8 is a schematic showing a side view of portions of a trailing gas shield attached to a laser welding head. For simplicity, neither front nor rear gas shield slide doors are shown.
[0023] Reference will now be made to the drawings in which similar segments in different drawings bear the same reference numerals.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention provides a shield that can be used to cover reactive metal alloys with inert gas during welding, surfacing or cladding operations. These operations can be performed with either high-power-density processes, such as lasers and out-of-vacuum electron beams, arc-assisted processes, such as GMAW (MIG) or GTAW (TIG), or plasma welding and/or cladding systems. The specific embodiment disclosed in detail herein is designed for use with a laser welding apparatus. However, this implementation of the shield is for illustrative purposes only and those skilled in the art readily appreciate that this invention can be utilized in conjunction with the other types of processes as indicated above. Moreover, many specific details of certain embodiments of the invention are set forth in the following description and shown in the drawings in order to provide a thorough understanding of these embodiments. One skilled in the art, however, will understand that the present invention may have additional embodiments, and that the invention may be practiced without several of the features described in detail below.
[0025] FIG. 1 is a schematic showing a side view of a trailing shield 2 in accordance with one embodiment of the invention. FIG. 2 shows an isometric view of the same trailing shield, but in an upside-down position. In this specific embodiment, the shield 2 has a ceiling 4 , opposing side walls 6 and 8 , and a leading wall 10 , portions of which serve as gas barriers forming a tunnel that is open at the trailing end, as best seen in FIG. 2 .
[0026] Still referring to FIG. 2 , the ceiling is formed by a base 4 in the shape of a beam with six generally rectangular faces; the side wall 6 is formed by a first subassembly attached to one side of the base 4 ; the side wall 8 is formed by a second subassembly attached to the other side of the base 4 ; and the leading wall 10 is formed by a third subassembly attached to the leading end of the base 4 . The first and second subassemblies have similar constructions, which construction is best seen in FIG. 6 (to be described in detail later). The side walls 6 and 8 have the same length and are substantially mutually parallel.
[0027] In an alternative embodiment (not shown), the shield can also be provided with a trailing wall, portions of which would form a gas barrier at the trailing end of the tunnel. That trailing wall may have a structure substantially similar to that of the leading wall (described in detail later with reference to FIGS. 3 and 7 ) and would be attached to the trailing end of the base.
[0028] The base 4 is provided with a U-shaped cooling channel (not shown in FIG. 2 ). Both legs of the U-shaped cooling channel terminate at respective ports formed in the trailing end face of base 4 . A first port is connected to a first coupling 80 that couples the first port to a pipe, hose or other conduit for cooling fluid. The other port is connected to a second coupling 82 that couples that port to another pipe, hose or other conduit for cooling fluid. Cooling fluid enters the U-shaped cooling channel via coupling 80 and exits via coupling 82 . The circulating fluid carries away heat from base 4 during the metal processing operation.
[0029] Referring now to FIGS. 1 and 6 , the basic structure of each side wall 6 , 8 will now be described. FIG. 6 is a sectional view taken along section line 6 - 6 indicated in FIG. 1 . Each side wall comprises a fixed side wall subassembly 12 , which is attached to the base 4 by means of a plurality of fasteners (not shown in FIG. 1 ), and a plurality of generally rectangular, vertically displaceable side wall segments 14 (hereinafter “gas shield slide segments”). The section line is located such that the fixed side wall assembly 12 is shown in section in FIG. 6 , but the gas shield slide segment 14 is not. Each gas shield slide segment 14 is vertically displaceable relative to the fixed side wall subassembly 12 supporting it. More specifically, each gas shield slide segment 14 is independently vertically displaceable relative to the fixed portion as the trailing shield 2 is carried in a horizontal plane across a contoured surface of a workpiece. When in contact with the workpiece surface, each slide segment 14 will be forced upward as it slides up a rising surface portion of the workpiece (as shown in FIG. 8 , to be described in detail later). After each rise, a deflected segment will be urged to return to its starting position by a compression spring 28 (see FIG. 6 ), which is compressed during upward gas shield slide segment displacement. Optionally, each gas shield slide segment 14 may be provided with a roller bearing for rolling contact with the workpiece surface.
[0030] As seen in FIG. 6 , each fixed side wall subassembly 12 comprises a side plate 16 , a spacer 18 , and a cover plate 20 . As best seen in the end view of FIG. 5 , the spacer 18 is attached to a topmost portion of the side plate 16 . As seen in FIG. 6 , the cover plate 20 is thereafter attached to the spacer 18 and side plate 16 . The side plate 16 , spacer 18 , and cover plate 20 may be fastened together by means of a plurality of fasteners 30 , seen, e.g., in FIG. 1 . The resulting subassembly has an inverted U-shape when viewed in section (see FIG. 6 ). The spacer 18 maintains a constant gap between side plate 16 and cover plate 20 , which gap will receive a portion of each vertically displaceable gas shield slide segment 14 , which, as seen in FIG. 6 , also has a U-shape.
[0031] Still referring to FIG. 6 , each gas shield slide segment 14 is a respective subassembly comprising a side plate 32 and a cover lid 34 . The cover lid 34 is an integral structure having a flange 36 for maintaining a constant gap G between the side plate 32 and the wall of the cover lid 34 . The gap G receives a portion of the cover plate 20 of the fixed side wall subassembly 12 , thereby effectively interleaving the U-shaped subassemblies 12 and 14 . For each gas shield slide segment 14 , the side plate 32 and the cover lid 34 are affixed to each other by means of a pair of fasteners 42 (see FIGS. 1-3 and 7 ). As seen in FIG. 2 , the side plate 32 of each gas shield slide segment 14 has a vertical slot 38 while the corresponding cover lids 34 are not slotted.
[0032] The interleaved U-shaped subassemblies 12 and 14 are coupled in a manner that allows each gas shield slide segment 14 to displace vertically (along the line of slot 38 ) relative to the fixed side wall assembly 12 . As seen in FIG. 8 , the feet 14 displace vertically independently in response to changes in the contour of the abutting surface 62 of the workpiece 60 being welded.
[0033] Referring to FIGS. 4 and 5 (which respectively show front and end views of a fixed side wall assembly with the cover plate removed), each gas shield slide segment 14 is guided to displace vertically by the interference of a respective pair of segment guide pins 24 and 26 with vertical slot 38 of the gas shield slide segment. Each segment guide pin 24 , 26 may have a threaded end and an unthreaded end, the former being screwed into a respective threaded bore (not shown) in the side plate 16 (see FIG. 5 ). Alternatively, each segment guide pin 24 , 26 could be unthreaded on both ends, with one end being press fit into a respective unthreaded bore in the side plate 16 . The upper limit position of each gas shield slide segment 14 is determined by abutment of the bottom end of slot 38 against guide pin 26 ; likewise the lower limit position of each gas shield slide segment 14 is determined by abutment of the top end of slot 38 against guide pin 24 .
[0034] As shown in FIG. 4 , each gas shield slide segment 14 is urged downward, toward its lower limit position, by means of a respective compression spring 28 (only one of which is shown) having ends respectively seated on spring placement pins 22 and 40 . The spacer 18 of each sidewall supports a plurality of spring placement pins 22 , one for each gas shield slide segment 14 . The spring placement pins 22 are fixed to the spacer 18 at regular spaced intervals approximately equal to the width of a gas shield slide segment 14 . Each spring placement pin 22 may have a threaded end and an unthreaded end, the former being screwed into a respective threaded bore (not shown) in the spacer 18 . Alternatively, the pins 22 could be unthreaded on both ends, with one end being press fit into an unthreaded bore in the spacer. Each gas shield slide segment 14 supports a respective spring placement pin 40 (only one of which is shown in FIG. 4 ), which may be screwed into a threaded bore or press fit into an unthreaded bore in the top of the side plate 32 of the gas shield slide segment 14 , as best seen in FIG. 6 .
[0035] As the contoured surface of the workpiece exerts a reaction force on the contacting portion of a gas shield slide segment 14 , the corresponding segment guide pins 24 and 26 interact with the sides of slot 38 of that gas shield slide segment to block horizontal displacement of the latter relative to the fixed side plate 16 , while allowing the gas shield slide segment to displace vertically upward toward its upper limit position. During this upward vertical movement, the associated spring 28 is compressed to provide a spring force that urges the gas shield slide segment 14 toward its lower limit position.
[0036] In accordance with the disclosed embodiment, the leading wall 10 (see FIGS. 3 and 7 ) comprises a fixed front plate 44 and a vertically displaceable front gas shield slide door. The fixed front plate 44 is fastened to the side wall assemblies by means of a pair of fasteners 46 . The front gas shield slide door comprises a cover plate 48 and a support fixture 52 . The support fixture 52 supports a roller bearing 54 that contacts and rolls along the surface of the workpiece. As the leading end of the trailing shield moves across a rising workpiece surface, the roller of roller bearing 54 rolls along that rising surface and the front gas shield slide door (including support fixture 52 and cover plate 48 attached thereto) is deflected upward.
[0037] The support fixture 52 is constrained to displace only vertically by means similar to the pin/slot arrangement previously described. In one implementation, the support fixture 52 has a slot 38 ′ (see FIG. 3 ) that is guided and constrained by a pair of guide pins (not shown but similar to segment guide own in FIG. 5 ) affixed to the front plate 44 . As a result, the support fixture 52 is vertically displaceable between upper and lower limit positions determined by abutment of the ends of slot 38 ′ against the respective guide pins affixed to the front plate 44 .
[0038] When displaced vertically upward away from its lower limit position, the support fixture 52 is urged downward by the spring force of a compression spring 70 having ends respectively seated on spring placement pins 72 and 74 . The spring placement pin 74 is fixed to the support fixture and has roller bearing 54 connected to the end thereof opposite to the end that locates spring 70 . The spring placement pin 72 is fixed to a mounting block 56 , the latter being in turn affixed to the front plate 44 by means of a pair of fasteners 58 . Each spring placement pin 72 , 74 may have a threaded end and an unthreaded end, the former being screwed into a respective threaded bore (not shown) in mounting block 56 or support fixture 52 . Alternatively, the spring placement pins 72 , 74 could be unthreaded on both ends, with one end being press fit into an unthreaded bore in mounting block 56 or support fixture 52 .
[0039] As seen in FIG. 7 , the mounting block 56 has a recess 76 that provides clearance for the upwardly extending portion 78 of the support fixture 52 during vertical displacement thereof. Likewise, a gap between vertical portion 78 and cover plate 48 provides clearance for the bottom portion of fixed front plate 44 during upward vertical displacement of support fixture 52 .
[0040] A person skilled in the art will readily appreciate that the trailing end of the trailing shield may be provided with gas shielding means similar in construction to the front gas shield slide door shown in FIG. 7 . More specifically, a rear gas shield slide door (not shown in the drawings) may be provided that comprises a fixed subassembly similar to that comprising items 44 , 56 and 72 seen in FIG. 7 and a vertically displaceable subassembly similar to that comprising items 48 , 52 , 54 and 74 seen in FIG. 7 .
[0041] FIG. 8 is a schematic showing a side view of portions of a trailing gas shield attached to a laser welding head 64 . For simplicity, neither front nor rear gas shield slide doors are shown. Inert gas is supplied to an interior volume of laser welding head 64 by an inert gas supply unit 68 . That inert gas flows through an opening in the bottom of the welding head and into the interior space of the trailing shield. The laser welding head comprises a lens 66 for directing a laser beam toward a junction between two workpieces (only one workpiece 60 being visible in FIG. 8 ) to be laser welded together. In this example, the workpieces have non-planar top surfaces (only the top surface 62 of workpiece 60 being indicated in FIG. 8 ). As the laser welding head is moved from left to right in FIG. 8 , the slide segments 14 of the trailing shield adjust vertically to the contour of the work surface 62 . FIG. 8 shows some of the slide segments at different elevations. At the same time the front and read slide doors (not shown in FIG. 8 ) adjust vertically as the contour of the work surface changes. The adjustable vertical displacement of the slide segments and slide doors reduces the amount of inert gas that escapes from the interior space of the trailing shield as the latter is moved across a work surface that is not parallel to the plane in which the trailing shield is being moved.
[0042] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for members thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the invention without departing from the essential scope thereof. Therefore it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
[0043] As used in the claims, the term “metal” encompasses both pure metals and alloys of two or more metals.
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A self-adjusting trailing shield for maintaining a volume of inert gas over a portion of a metal workpiece being subjected to a metal processing operation. The shield has segmented side walls, each segment being independently vertically displaceable as the shield is carried in a horizontal plane across a contoured surface of a workpiece. Each segment will be forced upward when it contacts and slides up a rising surface portion of the workpiece. Each segment is coupled to a respective spring that restores each deflected segment to its original, i.e., fully extended, position as the segment slides down a falling surface. The result is a continual reconfiguration of the segmented side walls that reduces the amount of inert gas escaping from the cover space during travel of the shield, as compared to a shield having rigid, not segmented, side walls.
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TECHNICAL FIELD
The present invention relates to a method for automatic bobbin changing in one or more shuttles of a weaving machine. Each shuttle can be introduced into a shuttle race and can be acted on to transfer the carried yard/thread from one side of the material/felt/weave, which is being produced in the weaving machine, to the other side of the material. Upon each change of bobbin in each shuttle, the shuttle is brought to a bobbin change position. Then a bobbin changer device is activated for bobbin changing and for joining together, preferably welding together, the yarn part issuing from the weave, felt and the like, and the yarn of the new bobbin. This invention also relates to a weaving machine with an automatic bobbin-changing function for one or more shuttles. Each shuttle can be introduced into a shuttle race and acted on to bring yarn/thread from the one side of the material (weave/felt) of the warp to the other side of the material of the warp. A bobbin changer device can be activated for bobbin changing and for joining together, for example welding together, the yarn part issuing from the material and the yarn of the new bobbin.
BACKGROUND OF THE INVENTION
Existing automatic bobbin-changing is used in, among other things, the weaving of endless felts, in which weaving use is made of shuttles which carry the weft yarn wound on a bobbin. The amount of thread wound on is sufficient only for 3 to 5 minutes of continuous weaving, and then the weaving machine has to be stopped and the empty bobbin has to be changed manually. This type of weaving means that each weaving machine has to be manned, otherwise the waiting time for bobbin changing may be too long if one and the same weaver is expected to attend to several weaving machines. This results either in high costs, caused by having one weaver per machine, or in a low efficiency, when one weaver is expected to attend to several machines, and both these alternatives are unfavorable with respect to production.
It is known to make use of so-called automatic bobbin changers which are offered for sale on the market. A possible example of these known bobbin changers is the bobbin changer sold on the market by the brand name Jurgens, Emsdetten, Germany.
The solutions which have been proposed in connection with the known automatic bobbin changers have serious disadvantages. Among other things, each bobbin is changed at the level of the shuttle race, which means that, in order to make room for the mechanics, the maximum weaving width of the weaving machine has to be reduced, or the side of the weaving machine has to be extended to provide room for the automatic bobbin changer. Such reductions of the maximum weaving width in most cases represent an unacceptable alternative. In many of the present day weaving mills, extensions to the weaving machine are quite impossible due to lack of space. The invention aims to solve these problems, among others.
In cases where automatic bobbin changers are used, it is important to be able to retain the existing functions of the weaving machine. Thus, for example, the spaces around the machine must not be limited to the extent that restrictions are placed on the drawing-in position of the machine. In such a drawing-in position, it will be possible to load the weaving machine for starting up a new weave. The invention also solves this problem.
It is also important to maintain the safety aspects of the weaving machine despite the introduction of the automatic bobbin-changing function. Thus, there must be no possibility of any danger arising when, for example, loading bobbins into the bobbin magazine of the automatic device while the weaving machine is running. The invention aims to solve this problem too.
It should be possible to use the automatic bobbin changer devices as additional equipment on already existing machines. The present invention solves this problem. In this respect, it will be possible to carry out so-called manual weaving despite the introduction or integration of the automatic device with the weaving machine functions. The present invention solves this problem too.
On account of the different space availabilities, there is a desire that it should be possible to apply the additional function of automatic bobbin changing on any chosen side of the machine, that is, either on the left-hand side or the right-hand side of the machine. The present invention solves this problem, too.
The automatic bobbin changer device should be able to work with a large number of bobbins, for example up to 40 bobbins, which gives approximately 3 working hours. In addition, it should be possible for the bobbin changer to have a simple constructional design and be built onto, or integrated with, existing weaving machines, newly produced weaving machines, or weaving machines which are in production. The present invention solves this problem, too.
SUMMARY OF THE INVENTION
The characteristic feature of the present invention is, among other things, that the bobbin changer position is located at a point above the shuttle race and preferably over areas of the material/warp. Furthermore, the bobbin changer device is made to perform its tasks above the material/warp, and preferably partly within the relevant side edge of the material/warp.
In further developments of the inventive concept, a bobbin changer compartment for each shuttle is formed by the bobbin changer device and the reed or sley of the weaving machine. Each shuttle which is to change its bobbin is transferred to the bobbin changing position, where the shuttle is fixed in its position during the actual bobbin change. The weaving machine operates with a shuttle changer which, in addition to placing the respective shuttle in the shuttle race, also operates at a position or a level above the shuttle race, where the respective shuttle which is to change bobbin can be removed, for example by the longitudinal displacement of the shuttle, to the bobbin changer compartment. In one embodiment, the bobbin changer device can be allocated any one of three positions. In a first position, the bobbin change takes place. In a second position, the weaving machine is allowed to perform its weaving function. In a third position, the bobbin changer device is moved to a height setting substantially above the weave/felt/warp, where the drawing-in work can be carried out in or on the machine.
In connection with the formation of the bobbin changer compartment by means of the reed or the sley, the bobbin changer device can be assigned various tilting positions in which it adapts to the exact position at which the reed or the sley has stopped at or near the limit edge of the material.
The characteristic feature of the present invention is that a bobbin changer position is arranged at a level which is above that of the shuttle race and preferably completely or partially within the relevant side edge of the material/the warp, and that the bobbin changer device effects the bobbin-changing function from a position above the material/the warp and at least partially within the side edge.
In further developments of the inventive concept, it is proposed that each shuttle which undergoes a bobbin change can be transferred from a position in a shuttle changer to a bobbin changer compartment, the transfer preferably taking place by the longitudinal displacement of the shuttle. The bobbin changer device is preferably arranged in such a way as to form, together with the reed or sley of the weaving machine (when the reed or sley assumes a position at or near a limit edge obtained in the material), the bobbin changer position or bobbin changer compartment. The bobbin changer device operates with preferably three different height settings. The bobbin changer device is preferably mounted on one or more guides in the upper structure of the weaving machine. In addition, the device is mounted so that it can tilt in order to be able to adapt to the current stop position of the reed or the sley upon each formation of the bobbin changer compartment. The bobbin change is initiated preferably by means of a member indicating a predetermined degree of unwinding, for example a reflection member. The bobbin changer compartment includes members for securely holding the shuttle present in the bobbin changer compartment. The bobbin changer device is likewise provided with transporting members that impart clear-cut displacement movements to the bobbins in the magazine. The bobbins can be identical, that is, carry the same type of thread. The bobbins can also comprise different types of thread, different colors of thread, and the like.
With the above features, an effective bobbin changer function is obtained which can be added to existing weaving machines or to weaving machines which are in production. Despite the bobbin changer function, no extensions need be made to the machine side in question. The bobbin changer functions can operate with functions which are known and which in addition are technically simple to use. As far as manual functions of the weaving machine are concerned, these can, if so desired, continue to be used as before or with the bobbin-changing function. Former weaving widths can be obtained on the weaving machine. Reference is also made to Swedish Patent Application 9400223-5 by the same applicant and inventor. This patent application proposes the use of a yarn-trapping function which makes it easier for each weft yarn to be kept under control. This allows loading the bobbin magazine with bobbins without having to stop the weaving machine, by virtue of the fact that the weft yarn can be kept under control with the aid of the proposed yarn-trapping function. In this connection it is possible to avoid using other types of complicated yarn control which can be dangerous for the personnel concerned to carry out, when the machine is in operation, because there may be a risk of getting one's fingers caught. Since the bobbin changer can be placed easily in a drawing-in position assigned to it, it is possible to carry out manual weaving, if so desired, without at the same time disturbing the drawing-in function.
BRIEF DESCRIPTION OF THE DRAWINGS
A presently proposed embodiment of a method and an arrangement according to the invention will be described hereinbelow with reference to the attached drawings, in which
FIG. 1 shows, in an end view of the weaving machine, and in partial cross section, the bobbin-changing function provided on the weaving machine, with the components involved being in their respective first positions;
FIG. 2 illustrates the device as in FIG. 1, but with the components being in their respective second positions; and
FIG. 3 shows, in a vertical view from the side, the automatic bobbin changer arranged on or by a weaving machine, which has been symbolized by its relevant parts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The method and the device according to the present invention differ from the prior art principally in that each bobbin for each shuttle is changed at a level above the level of the shuttle race, at a position which is situated over the woven felt/warp and within the relevant side edge of the felt or the warp, the result and advantage of this being that the maximum weaving width can be maintained. In FIG. 1, three cloth beams are indicated by 1, 2 and 3. A woven felt is labelled as 4. In addition, a reed or sley is shown by 5. The weaving machine also includes a shuttle changer 6 which is known and which can operate with five positions. The shuttle changer is designed with four compartments 7, 8, 9 and 10. The shuttle changer can be of the type which comprises a cylinder 6a which, in a known manner, can set the compartments 7, 8, 9 and 10 at different heights. Thus, in FIG. 1, the compartment 7 is set at a level which corresponds to the shuttle race. A shuttle placed in the compartment 7 can thus be transferred from a first side 12 of the weave/felt/warp to a second side 13 of the same. The transfer can be effected in a known manner. As regards the basic functions of the weaving machine in the respects mentioned here, reference may be made to the weaving machines sold by TEXO AB, Sweden, for wires. The shuttle race level is indicated by the arrow N1.
In accordance with the present invention, the weaving machine according to FIG. 1 comprises an automatic bobbin changer device 14. The bobbin changer device comprises one or more magazines with bobbins 15. Thus, for example, the device 14 can comprise a magazine with 4 vertical rows of 10 bobbins, one of the rows being shown in FIG. 1. The bobbin changer also comprises members for joining yarn or thread. In the illustrative embodiment, the joining members 16 include a welding device of a known type. The welding device is vertically displaceable in the directions of the arrows 17 relative to the frame 14a of the bobbin changer. In the present case, the bobbin changer device is at a height setting which is here called the weaving position. The level at the weaving position is indicated by N2. The vertical distance A has been chosen as 274 mm in this case. The distance A can of course be different and is calculated from the shuttle race to the bottom edge or underside 14b of the bobbin changer.
In accordance with FIG. 2, the bobbin changer can be assigned a lowered position at a change-over level which in FIG. 2 is indicated by N3. In FIG. 2 it has been assumed that the shuttle 11' in the uppermost compartment 7' of the shuttle changer 6' is to be changed. The shuttle changer has therefore set the compartment 7' at the change-over level N3, which is located above the level N1 of the shuttle race. The vertical distance B between the levels N1 and N3 has been chosen as about 74 mm in the present case. The distance B can also be varied without deviating from the inventive concept. The direction of the vertical movement (the lowering movement) has been indicated by the arrow 18. The bobbin changer device 14' forms, together with the reed or sley (see below), a bobbin changer compartment 19, in which the shuttle 11' can be brought to a position 11" by longitudinal displacement in the direction of the arrow 20. Longitudinal displacement members are designated by 21 and can be placed in the bobbin changer compartment 19 or in the shuttle changer compartment 7'. These longitudinal displacement members 21 can be of known types. The bobbin-changing function itself is also assumed to be known, and in this respect reference may be made to the functions of the above mentioned automatic bobbin changer sold on the market. The bobbin-changing function also includes welding the yarn part 4a, issuing from the felt/weave/material in question, to the yarn part 22 of the bobbin in question. Reference is also made to the above cited Swedish patent application.
The view shown in FIG. 3 also illustrates, in addition to the components which have been mentioned, a breast beam 23, a back rest 24 and a guide roll 25. A warp beam is further indicated by 26. The movement of the reed or sley 5' is shown by the arrows 27. The warp shed has been shown by broken lines 28 and 29. The FIGURE also reveals that the bobbin changer device 14" is provided with a frame part 41 which has, in its lower areas, a portion 41a which can bear against the front side 5a of the reed or sley 5' The portion 41a is designed for forming the bobbin changer compartment 19' The position of the relevant shuttle in the bobbin changer compartment is indicated by 11'". The view according to FIG. 3 also shows all the rows of bobbins 15'. The bobbins can be transferred by transfer members which are symbolized by 30 and which are of a known type. The transfer members are arranged to impart to each bobbin, at each bobbin change, clear-cut displacement movements to the compartment 19'.
The device 14" can be tilted about a bearing point/bearing shaft 31, the tilting being executed in the plane of the paper. The tilting movement is effected by means of a swing cylinder 32, which is of a known type, by allowing the piston 32a of the swing cylinder to act on a frame part 14c. As above, the whole device can be displaced vertically, the bobbin change-over level N3' being adopted in FIG. 3. The vertical displacement takes place on one or more guides 33 arranged in the upper structure of the weaving machine symbolized by 34. A level N4 is indicated in FIG. 3. The bobbin changer device can be brought to this height setting, so that its lower areas arrive at or are situated near the level N4. The vertical displacement movements for the bobbin changer device can be effected by means which are known. In FIG. 3, a cylinder acting in the vertical direction has been indicated by 35.
By means of what has been indicated above, a preliminary securing of the shuttle, which has been introduced into the bobbin changer compartment 19', can be obtained with the device and the sley. A definitive securing of the shuttle is effected by members that are known and, therefore, not specifically shown. In FIG. 1, a reflection surface is indicated by 11a'. As this reflection surface is exposed after a predetermined degree of unwinding of the yarn on the shuttle in question, an indication of this is obtained with the aid of the reflection surface. Reading or sensing members that react to the exposure of the reflection surface can consist of members that are known and that are symbolized by 36 in FIG. 1. Members 36 initiate a control unit 37, which in turn sends control signals 38 and 39 to the shuttle changer and the automatic unit, respectively. A stop signal 40 for the machine is also initiated. The automatic unit in the bobbin changer device can operate internally as a function of control signals coming from outside (for example, the control 39). One or more of the various part-functions in the bobbin changer device can alternatively be controlled from the control unit 37.
Level N4 (see FIG. 3) is arranged at a distance C which, in the shown embodiment, is chosen at about 674 mm above the level of the shuttle race. Level N4 of the bobbin changer device permits the drawing-in position, in which handling of the yarn is made easier when starting-up the weaving machine with new weave, so-called drawing-in. In the shown embodiment, a 4-cell shuttle box which is maneuvered with a shuttle changer having 5 positions, that is, 5 cell divisions, has been used. The fifth position is used, upon bobbin change-over, for lifting the shuttle box one position above the level of the shuttle race. Different number of cells and shuttle changer positions can of course be used in connection with the present invention. The present position of the reed or shuttle can vary from one stop to another. Even if the variation is small, it is important that the arrangement in accordance with the above takes care of these variations. With the aid of the swing cylinder and the weight of the device, the change-over compartment is laid against the front side of the reed, and stop variations are eliminated. The limit edge of the weave 4 is designated as 4b.
The present invention is not limited to the embodiment shown above by way of example, but instead can be modified within the scope of the attached patent claims and the inventive concept.
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A method and apparatus for automatically changing a bobbin in at least one shuttle of a weaving machine which carries thread from one side of material produced by the weaving machine to the other side of the material. The weaving machine includes a bobbin changer having at least one bobbin and device for joining thread together. The bobbin changer is moveable between a first weaving position at a height level above the material and on a side edge of the material and a second bobbin change position above a shuttle race level and at least partly over the material upon each change of the bobbin. At least one shuttle is positioned in a first position corresponding to the second bobbin change position of the bobbin changer and a change of the bobbin in the shuttle is effected.
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TECHNICAL FIELD
[0001] The invention relates to electrolytes for use in energy storage devices. In particular, the invention relates to non-aqueous electrolytes capable of high temperature operation in capacitors and supercapacitors.
[0002] The invention has been developed primarily for supercapacitors and will be described hereinafter with reference to that application. It will be appreciated, however, that the invention is not limited to that particular field of use and is also suitable for other energy storage devices such as batteries, fuel cells, pseudocapacitors and capacitors and hybrids of one or more of these devices.
BACKGROUND ART
[0003] Supercapacitors, alternatively known as ultracapacitors, electrical double layer capacitors or electrochemical capacitors, are energy storage devices that have considerably more specific capacitance than conventional capacitors. Low resistance supercapacitors are ideally suited for high power applications for mobile devices, particularly those using GSM (Global System for Mobile communication) and GPRS (General Packet Radio Service) wireless technologies.
[0004] Supercapacitors can play a role in hundreds of applications. The energy and power storage markets, where supercapacitors reside, are currently dominated by batteries and capacitors. It is well recognised that batteries are good at storing energy but compromise design to enable high power delivery of energy. It is also well recognised that capacitors enable fist (high power) delivery of energy, but that the amount of energy delivered is very low (low capacitance). Overlaying these limitations of existing batteries and capacitors against market demand reveals the three main areas of opportunity for supercapacitors, battery replacement, devices which have higher energy density, bad complements, devices which have high power and energy densities; and capacitor replacement, devices which are smaller and not only have high power density but have high frequency response.
[0005] Currently, the relatively high power density of supercapacitors make them ideal for parallel combination with batteries that have high energy density to ram a hybrid energy storage system. When a load requires energy that is not constant, complementing the battery with a supercapacitor allows the peaks to be drawn from the charged-up supercapacitor. This reduces tie load on the battery and in many cases extends the lifecycle of a battery as well as the lifetime of rechargeable batteries.
[0006] Modern mobile devices require power systems that arm capable of dealing with large fluctuations in the load. For example, a mobile telephone has a variety of modes each with a different load requirement. There is a stand-by mode, which requites low power and is relatively constant. However, this mode is periodically punctuated by the need to find the nearest base station and a signal is sent and received, requiring a higher load. In full talk mode where continuous contact to a base station is required, the load takes the form of a periodic signal where the instantaneous load is quite different from the average. A number of communication protocols exist, such as GSM and GPRS, but they are all characterized with a periodic load. The parallel supercapacitor-batty hybrid is particularly suited to this application because the power from the supercapacitor is used during the high loads that are usually short in duration and the energy from the battery can recharge the supercapacitor and supply a base load during the time of low power demand. As further miniaturization of digital wireless communication devices occur, leading to decreased battery sizes, the need for supercapacitors will increase.
[0007] Supercapacitors also have application in the field of Hybrid Electric Vehicles (HEV). Supercapacitors can be used as an integral component of the drivetrains of these vehicles and are used as the primary power source during acceleration and for storage of energy reclaimed during regenerative braking. Such vehicles could conceivably halve a motorist's fuel bill and slash emissions by up to 90%.
[0008] Capacitance arises when two parallel plates are connected to an external circuit and a voltage difference is imposed between the two plates, the surfaces become oppositely charged. The fundamental relationship for this separation of charges is described by the following equation
C = ɛ A L
where C denotes capacitance with a unit of farads (F), ε is the permittivity with a unit of farads per metre (m), A is the area of overlap of the charged plates and L is the separation distance. The permittivity of the region between the plates is related to the dielectric constant of the material that can be used to separate the charged surfaces.
[0009] The problem with exiting commercial capacitors using conventional materials is that their performance is limited by their dimensions. For example, a capacitor based around a metallized coating of a polyethylene sheet that is 50 μm thick will develop only 0.425 μF for one square metre of capacitor. Thus, over 2.3 million square metres will be required to develop 1 F.
[0010] The supercapacitors developed by the present applicant are disclosed in detail in the applicants copending applications, for example, PCT/AU98/00406, PCT/AU99/00278, PCT/AU99/00780, PCT/AU99/01081, PCT/AU00/00836 and PCT/AU01/00553, the contents of which are incorporated herein by reference.
[0011] These supercapacitors developed by the applicant overcome the dimensionality to problem described above by using as a coating material an extremely high surface area carbon.
[0012] These supercapacitors include two opposed metal electrodes. These electrodes are coated and are maintained in a predetermined spaced apart electrically isolated configuration by an intermediate electronically insulating separator. In very broad terms, the electrodes form current collectors for the coating material, in that the metal offers significantly less resistance than the coating material. The coatings typically formed from a particulate carbon or carbons and a binder used for adhering the carbon to itself and to the associated current collector.
[0013] The coated electrodes and intermediate separator can be either stacked or wound together and disposed within a housing that contains an electrolyte. Two current collecting terminals are then connected to and extend from respective electrodes for allowing external access to those electrodes. The housing is sealed to prevent the ingress of contaminants and the egress of the electrolyte. This allows advantage to be take of the electrical double layer that forms at the interface between the electrodes and the electrolyte. That is, there are two interfaces, those being formed between the respective electrodes and the electrolyte. This type of energy storage device is known as a supercapacitor. Alternatively, these have been known as ultracapacitors, electrical double layer capacitors and electrochemical capacitors.
[0014] The electrolyte contains ions that are able to freely move throughout a matrix, such as a liquid or a polymer, and respond to the charge developed on the electrode surface. The double layer capacitance results from the combination of the capacitance due to the compact layer (the layer of solvated ions densely packed at the surface of the electrode) and the capacitance due to the diffuse layer (the less densely packed ions further from the electrode).
[0015] In supercapacitors, the compact layer is generally very thin, less than a nanometre, and of very high surface area. This is where the technological advantage for supercapacitors over conventional capacitors lies, as charge storage in the extremely thin compact layer gives rise to specific capacitances of approximately 0.1 Fm −2 . This is an increase by several hundred thousand-fold over conventional film capacitors. As well, the applied potential controlled, reversible nanoscale ion adsorption/desorption processes result in a rapid charging/discharging capability for supercapacitors.
[0016] The electrode material may be constructed as a bed of highly porous carbon particles with a very high surface area. For example, surface areas may range from 100 m 2 per gram up to greater than 2500 m 2 per gram in certain preferred embodiments. The colloidal carbon matrix is held together by a binding material that not only holds the carbon together (cohesion) but it also has an important role in holding the carbon layer onto the surface of the current collecting substrate (adhesion).
[0017] The current collecting substrate is generally a metal foil. The space between the carbon surfaces contains an electrolyte (frequently solvent with dissolved salt). The electrolyte is a source of ions which is required to form the double layer on the surface of the carbon as well as allowing ionic conductance between opposing electrodes. A porous separator is employed to physically isolate the carbon electrodes and prevent electrical shorting of the electrodes.
[0018] The energy storage capacity for a supercapacitor can be described by the equation
E = 1 2 CV 2
where E is the energy in joules and V is the rated or operating voltage of the supercapacitor. Apart from the voltage limitation, it is the size of the supercapacitor that controls the amount of energy stored, and the distinguishing feature of supercapacitors are the particularly high values of capacitance. Another measure of supercapacitor performance is the ability to store and release the energy rapidly; this is the power, P, of a supercapacitor and is given by
P = V 2 4 R
where R is the internal resistance of the supercapacitor. For capacitors, it is more common to refer to the internal resistance as the equivalent series resistance or ESR. As can be deduced from the foregoing equations, the power performance is controlled by the ESR of the entire device, and this is the sum of the resistance of all the materials, for instance, substrate, carbon, binder, separator, electrolyte and the contact resistances as well as between the external contacts.
[0019] One variable of interest in the field of supercapacitors that has yet to be fully explored is the nature of the electrolyte involved. The electrolyte is typically one or more solvents containing one or more dissolved ionic species. In many cases, the physical and electrochemical properties of electrolyte are a key factor in determining the internal resistance (ESR) of the supercapacitor and the ¢power spectrum” of the supercapacitor, ie the ability of the supercapacitor to provide power over various time domains or in various frequency ranges.
[0020] The factors influencing the conductance (κ) of an electrolyte solution are described in detail in an article by B. E. Conway taken from “The Fourth International Seminar on Double Layer Capacitors and Similar Energy Storage Devices”, Dec. 12-14, 1994, held at Ocean Resort Hotel and Conference Centre, Deerfield Beach, Fla. and co-ordinated by Florida Educational Seminars, Inc., 1900.Glades Road, Suite 358, Boca Raton, Fla. 33431.
[0021] In summary, there are two principle factors which are involved in determining the conductance—these are:
a) the concentration of free charge carriers, cations and anions; and b) the ionic mobility or conductance contribution per dissociated ion in the electrolyte.
[0024] There are a number of sub factors which in turn influence these two principle factors. These are:
The solubility of the selected salt. The degree of dissociation into free ions and factors such as the extent of ion-pairing of the ionic species. This in turn is influenced by the salt concentration, temperature and the dielectric constant of the solvent. The viscosity of the solvent, which is a temperature dependent property. As temperature increases, there is a corresponding decrease in viscosity.
[0028] Solvents for supercapacitors can thus be designed with the following criteria in mind:
Solvent for selected ionic species Degree of dissociation of cation/anion pairing in solution Dielectric constant Electron-pair donicity Permits high ion mobility Extent of solvation of free ions and radii of solvated ions Temperature coefficient of viscosity (ie low viscosity in the intended temperature range) and ion pairing equilibria.
[0036] There is also the necessity for the solvent to be chemically stable. Aqueous based electrolytes, such as sulfuric acid and potassium hydroxide solutions, are often used as they enable production of an electrolyte with high conductivity. However, water is susceptible to electrolysis to hydrogen and oxygen on charge and as such has a relatively small electrochemical window of operation outside of which the applied voltage will degrade the solvent. In order to maintain electrochemical stability in applications requiring a voltage in excess of 1.5V, it is necessary to employ supercapacitor cells in series, which leads to an increase in size in relation to non-aqueous devices. Stability is important when one considers that the supercapacitors must charge and discharge many hundreds of thousands of times during the operational lifetime of the supercapacitor.
[0037] There are of course processing requirements on the solvent also, such as cost, toxicity, purity and dryness considerations.
[0038] Non aqueous solvents commonly used in related fields, eg batteries, can be classified as: high dielectric constant aprotic (e.g. organic carbonates), low dielectric constant with high donor number (e.g. dimethoxyethane, tetrahydrofuran or dioxolane), low dielectric constant with high polarisability (e.g. toluene or mesitylene) or intermediate dielectric constant aprotic (e.g. dimethylformamide, butyrolactone) solvents.
[0039] However, in addition to the specific electrolyte requirements of supercapacitors mentioned above, there is also the practical consideration that supercapacitors do not operate in isolation. Rather, in use, they are in confined environments in the presence of components which generate high temperatures, and like the other components, this must be borne in mind when selecting the electrolyte solvent. Also, it needs to be borne in mind that the supercapacitors must be capable of operation at start-up at temperatures much lower (even into the sub zero range) than the high operating temperatures referred to above.
[0040] The energy storage of batteries, in contrast to the power delivery of supercapacitors, is not critically dependent on the contribution of the electrolyte to the ESR of the cell, although even in batteries, low ESR is desirable. Solvents which have high boiling points invariably have high viscosities, and consequently, low charge mobilities at low temperatures. High boiling solvents, such as cyclic ethers and lactones can therefore be used in batteries with less regard to what would be an unacceptably high ESR in supercapacitors.
[0041] FIG. 1 shows the relationship between literature boiling point and viscosity for a number of substances.
[0042] FIG. 2 shows the relationship between conductivity and reciprocal solvent viscosity at 25° C. for 0.65M tetraethylammonium tetrafluoroborate (TEATFB) for a variety of solvents. Source: Makoto Ue, Kazuhiko Ida and Shoichiro Mori; “ Electrochemical Properties of Organic Liquid Electrolytes Based on Quaternary Onium Salts for Electrical Double - Layer Capacitors.” J. Electrochem. Soc., Vol. 141, No. 11, November 1994
[0043] FIG. 3 is a plot of ESR and reciprocal conductivity, where the conductivity is varied by changing the concentration of TEATFB in acetonitrile, and shows in a general way the relationship between ESR and conductivity for a supercapacitive cell.
[0044] These three Figures also serve to illustrate the other relationships that exist between the properties, such as boiling point and ESR, viscosity and ESR and boiling point and conductivity.
[0045] Admixing a low boiling fluid and a high boiling fluid may appear to be an attractive option, with the low boiling, low viscosity compound providing acceptable charge mobility at the low end of the temperature range, and the high boiling component reducing in viscosity and providing charge mobility at higher temperatures. In practice, however, this approach is generally not viable because while acceptable results may be achieved at ambient temperatures, at higher temperatures the low boiling component will fractionate out. Fractionation can present a challenge to the mechanical integrity of the supercapacitor packaging.
[0046] It is an object of the present invention to provide a non-aqueous solvent suitable for use in the energy storage device which overcomes one or more of the abovementioned disadvantages, or at least provides a commercially viable alternative.
SUMMARY OF THE INVENTION
[0047] According to a first aspect, the invention provides a non-aqueous solvent system suitable for use as an electrolyte solvent in an energy storage device, said non aqueous solvent system including:
at least one low boiling component, at least one high boiling component compatible with said low boiling component; and wherein the components are selected in an amount such that said non-aqueous solvent system does not boil at the boiling point of the low viscosity solvent alone but has a boiling point greater than said low viscosity solvent alone.
[0051] Alternatively, the invention may be described as providing a non-aqueous solvent system suitable for use in an energy storage device including a plurality of compatible component solvents each with a corresponding component solvent boiling point, and wherein the non-aqueous solvent system has at least one boiling point not corresponding to a component solvent boiling point.
[0052] Preferably the energy storage device is a supercapacitor. More preferably, the energy storage device is a carbon based supercapacitor, that is, a supercapacitor that has carbon as a component of the electrodes.
[0053] The energy storage devices of the present invention may be in the form of cells or devices, and may include a number of cells in series or parallel.
[0054] Preferably, the non-aqueous solvent system is a combination of a low viscosity solvent and one or more compatible high viscosity solvents.
[0055] Preferably the low viscosity/low boiling component is a nitrile, most preferably acetonitrile (“AN”).
[0056] The high viscosity/high boiling component is preferably one or more of a lactone, such as γ-butyrolactone (“GBL”), or an organic carbonate such as ethylene carbonate (“EC”), propylene carbonate (“PC”) or mixtures or derivatives thereof.
[0057] Preferably, the species are complexed or associated and provide a synergistic change in boiling point. Preferably, the species are in a mole ratio selected to provide an electrolyte solvent with a boiling point different from the boiling point of the low viscosity solvent.
[0058] In one preferred embodiment, the sum of the moles of the low boiling components is less than the sum of the moles of the high boiling components. In an alternative preferred embodiment, the sum of the moles of the low boiling components is equal to the sum of the moles of the high boiling components. In another alternative preferred embodiment, the sum of the moles of the low boiling components is greater than the sum of the moles of the high boiling components.
[0059] In a preferred embodiment, the invention provides a non-aqueous solvent system suitable for use as an electrolyte solvent in an energy storage device, said non aqueous solvent system including:
a nitrile, at least one of a lactone or a carbonate compatible with said nitrile; and wherein the components are selected in an amount such that said non-aqueous solvent system does not boil at the boiling point of the nitrile but has a boiling point greater than the boiling point of the nitrile.
[0062] In one particularly preferred embodiment, the invention provides a non-aqueous solvent system including acetonitrile, γ-butyrolactone, and ethylene carbonate. Even more preferably, the invention provides a non-aqueous solvent system including acetonitrile, γ-butyrolactone, and ethylene carbonate in a mole ratio of 3:2:1 to 3:1.72:1.
[0063] In another particularly preferred embodiment, the invention provides a non-aqueous solvent system including acetonitrile, γ-butyrolactone, and propylene carbonate. Even more preferably, the invention provides a non-aqueous solvent system including acetonitrile, γ-butyrolactone, and propylene carbonate in a mole ratio of 3:2:1 to 3:1.72:1.
[0064] In yet another particularly preferred embodiment, the invention provides a non-aqueous solvent system including acetonitrile, propylene carbonate and ethylene carbonate. Even more preferably, the invention provides a non-aqueous solvent system including acetonitrile, propylene carbonate and ethylene carbonate in a ratio of 2:1:1.
[0065] Other preferred embodiments include 2AN:GBL:PC and 2AN:GBL:EC
[0066] Without wishing to be limited to the particular solvents which may be used, the high boiling high viscosity solvents and/or low boiling low viscosity solvents may be selected independently from the following list. It will be understood that high boiling and low boiling, and likewise high viscosity and low viscosity, are relative terms and represent properties of the component solvents relative to one another.
[0067] Suitable solvents include: ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropionitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N-methypyrrolidinone, N-methyloxazolidinone, N-N′-dimethylimisazolidinone, nitromethane, nitroethane, sulfolane, dimethyl sulfoxide, trimethyl phosphate, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, 1-methyl-2-pyrrolidone, 1,2-dichloroethane, sulphuryl chloride, thionyl chloride, acetyl chloride, tetrachloroethylene carbonate, benzoyl chloride, dichloroethylene carbonate, nitrobenzene, acetic anhydride, phosphorus oxychloride, benzonitrile, selenium oxychloride, propanediol-1,2-carbonate, benzylcyanide(nitrile), ethylene sulphite, iso-butyronitrile, propionitrile, phenylphosphonic difluoride, n-butyronitrile, acetone, ethyl acetate, phenylphosphonic dichloride, diethyl ether, diphenyl phosphonic chloride, trimethyl phosphate, tributyl phosphate, pyridine, hexamethyl phosphoramide and the like.
[0068] The non-aqueous solvent systems of the present invention have a boiling point of at least 85° C., more preferably at least 90° C. and even more preferably at least 100° C.
[0069] Preferably, the non-aqueous solvent systems of the present invention further include an ionic species at least partially soluble therein, such as a salt, which may be in one preferred embodiment tetraethylammonium tetrafluoroborate. The ionic species may be present in an amount up to saturation, or in greater or lesser quantities such as 1 molar and in an amount sufficient to allow an energy storage device to function over the desired temperature range.
[0070] Preferably, the non-aqueous solvent systems of the present invention include an ion source. The ion source may be present in an amount up to saturation at −30° C. or in an amount up to saturation at any temperature, having regard to the operational requirements of the device. Tetraethylammonium tetrafluoroborate is particularly preferred. In one highly preferred embodiment, a 1 molar (at ˜23° C.) solution of tetraethylammonium tetrafluoroborate in the solvents of the present invention have a conductivity of at least 40 mS/cm at 85° C., more preferably at least 50 mS/cm at 85° C., even more preferably at least 55 mS/cm at 85° C. and most preferably at least 60 mS/cm at 85° C. It is preferable that the non aqueous systems of the present invention are suitable four use as high temperature solvents and/or low temperature solvents.
[0071] According to a second aspect, the invention provides a method of increasing the boiling point of a non-aqueous low boiling low viscosity solvent suitable for use in an energy storage device, said method including the step of combining said non-aqueous low boiling low viscosity solvent with at least one compatible high boiling high viscosity solvent.
[0072] According to a third aspect, the invention provides a method of decreasing the viscosity of a high boiling high viscosity solvent suitable for use in an energy storage device, said method including the step of combining said high boiling high viscosity solvent with at least one compatible second liquid.
[0073] According to a fourth aspect, the invention provides a method of increasing the useful operational temperature range of a solvent suitable for use in an energy storage device, said method including the step of combining a low boiling low viscosity solvent with at least one compatible high boiling high viscosity solvent.
[0074] According to a fifth aspect, the invention provides a high temperature solvent suitable for use in an energy storage device, said high temperature solvent including acetonitrile, γ-butyrolactone and ethylene carbonate. In an alternative embodiment, the high temperature solvent includes acetonitrile, γ-butyrolactone and propylene carbonate. A further alternative embodiment of the high temperature solvent includes acetonitrile, propylene carbonate and ethylene carbonate.
[0075] According to a sixth aspect, the invention provides a low temperature solvent suitable for use in an energy storage device, said low temperature solvent including acetonitrile, γ-butyrolactone and ethylene carbonate. In an alternative embodiment, the low temperature solvent includes acetonitrile, γ-butyrolactone and propylene carbonate. A further alternative embodiment of the low temperature solvent includes acetonitrile, propylene carbonate and ethylene carbonate.
[0076] According to a seventh aspect, the invention provides an energy storage device including the non-aqueous solvent system of the present invention. In one preferred embodiment the device includes acetonitrile, γ-butyrolactone and ethylene carbonate.
[0077] In an alternative embodiment, the energy storage device may include a solvent including acetonitrile, γ-butyrolactone and propylene carbonate. A further alternative embodiment of the energy storage device may include a solvent including acetonitrile, propylene carbonate and ethylene carbonate.
[0078] Preferably the energy storage device is a capacitor or supercapacitor.
[0079] According to an eighth aspect, the invention provides a method of predetermining the ESR of an energy storage device at a predetermined temperature, said method including the step of providing to the energy storage device a solvent system including at least one low boiling component, at least one high boiling component compatible with said low boiling component; and wherein the components are selected in an amount such that said non-aqueous solvent system does not boil at the boiling point of the low viscosity solvent alone but has a boiling point greater than said low viscosity solvent alone.
[0080] According to a ninth aspect, the invention provides a method of predetermining the conductivity of an energy storage device at a predetermined temperature, said method including the step of providing to the energy storage device a solvent system including at least one low boiling component, at least one high boiling component compatible with said low boiling component; and wherein the components are selected in an amount such that said non-aqueous solvent system does not boil at the boiling point of the low viscosity solvent alone but has a boiling point greater than said low viscosity solvent alone.
[0081] The preferred solvent systems include, but are not limited to: acetonitrile, γ-butyrolactone and ethylene carbonate; acetonitrile, γ-butyrolactone and propylene carbonate or acetonitrile, ethylene carbonate and propylene carbonate.
[0082] According to a tenth aspect, the invention provides a supercapacitor having an ESR of no more than 1013 mΩ cm 2 at 23° C., preferably no more than 862 mΩ cm 2 at 23° C. and even more preferably no more than 449 mΩ cm 2 at 23° C. and an ESR of no more than 7840 mΩ cm at −30° C., preferably no more than 3685 mΩ cm 2 at −30° C. and even more preferably no more than 986 mΩ cm 2 at −30° C.
[0083] Where ESR is described in terms of resistance multiplied by unit area, it will be understood by those skilled in the art that this refers to the geometric area of the current collector. Also, in those cases where the devices have differently sized current collectors, it will be understood that the resistance values relate to the area of the smallest current collector.
[0084] According to an eleventh aspect, the invention provides a supercapacitor having an ESR of no more than 784 mΩ cm 2 at −85° C., preferably no more than 670 mΩ cm 2 at 85° C. and even more preferably no more than 508 mΩ cm 2 at 85° C. and an ESR of no more than 7840 mΩ cm 2 at −30° C., preferably no more than 3685 mΩ cm 2 at −30° C. and even more preferably no more than 778 mΩ cm 2 at −30° C.
[0085] According to a twelfth aspect, the invention provides a supercapacitor having an ESR of no more than 784 mΩ cm 2 at 85° C., preferably no more than 670 mΩ cm 2 at 85° C. and even more preferably no more than 508 mΩ cm 2 and an ESR of no more than 946 mΩ cm 2 at 23° C. and preferably no more than 862 mΩ cm 2 at 23° C. and even more preferably no more than 449 mΩ cm 2 at 23° C.
[0086] According to a thirteenth aspect, the invention provides a supercapacitor having an ESR of no more than 784 mΩ cm 2 at 85° C. and preferably no more than 670 mΩ cm 2 at 85° C. and even more preferably no more than 508 mΩ cm 2 at 85° C. and an ESR of no more than 946 mΩ cm 2 at 23° C., preferably no more than 862.4 mΩ cm 2 at 23° C., and even more preferably an ESR of no more than 544 mΩ cm 2 at 23° C. and an ESR of no more than 7840 mΩ cm 2 at −30° C. and preferably no more than 3685 mΩ cm 2 at −30° C. and even more preferably no more than 778 mΩ cm 2 at −30° C.
[0087] According to a fourteenth aspect, the invention provides a supercapacitor having an ESR of no more than 771 mΩ cm 2 at 80° C., preferably no more than 424 mΩ cm 2 at 80° C.
[0088] According to a fifteenth aspect, the invention provides a supercapacitor having an ESR of no more than 741 mΩ cm 2 at 90° C., preferably no more than 412 mΩ cm 2 at 90° C.
[0089] According to a sixteenth aspect, the invention provides a supercapacitor having an ESR of no more than 717 mΩ cm 2 at 100° C., preferably no more than 401 mΩ cm 2 at 100° C.
[0090] According to a seventeenth aspect, the invention provides a supercapacitor having an ESR of no more than 675 mΩ cm 2 at 120° C., preferably no more than 382 mΩ cm 2 at 120° C.
[0091] According to an eighteenth aspect, the invention provides a supercapacitor having an ESR of no more than 657 mΩ cm 2 at 130° C., preferably no more than 373 mΩ cm 2 at 130° C.
[0092] According to a nineteenth aspect, the invention provides a supercapacitor having an ESR of no more than 641 mΩ cm 2 at 140° C., preferably no more than 366 mΩ cm 2 at 140° C.
[0093] The supercapacitors of the present invention may have any combination of one or more of the ESR/temperature relationships mentioned above.
[0094] In one highly preferred aspect of the invention, the supercapacitors have an ESR of no more than (((1044.3/(0.3948*(T)+25.852))+6.5178)*28) [Series X with 50 μm Separator] and more preferably no more than (((777.58/(0.3948*(T)+25.852))+6.741)*28) [Series Z with 50 μm Separator] and even more preferably no more than (((649.32/(0.3948*(T)+25.852))+8.7202)*28) [Series Z with 20 μm Separator] where all units are in mΩ cm 2 at temperature T(° C.).
[0095] In an alternative aspect, where the device is a multilayer electrode stack device, as may be preferred in production cells, the ESR is preferably no more than (((1051.2/(0.3948*(T)+25.852))+13.282)*24.4) mΩ cm 2 .
[0096] These values are applicable for single cell devices. Where two or more cells are connected in series, a much higher value in mΩ cm 2 will be obtained.
[0097] Preferably, the supercapacitors are high temperature supercapacitors.
[0098] According to a twentieth aspect, the invention provides a supercapacitor having a non aqueous solvent system and an ESR at −30° C. of no more than. 7.4, more preferably no more than 4.5, even more preferably no more than 3.4 and most preferably no more than 2.0 times the ESR at −30° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0099] The non aqueous solvent systems are preferably binary or ternary.
[0100] According to a twenty first aspect, the invention provides a supercapacitor having a non aqueous solvent system and an ESR at −20° C. of no more than 2.7, more preferably no more than 2.2, even more preferably no more than 2.1 times the ESR at −20° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0101] According to a twenty second aspect, the invention provides a supercapacitor having a non aqueous solvent system and an ESR at 23° C. of no more than 1.8, more preferably no more than 1.5, even more preferably no more than 1.2 times the ESR at 23° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0102] According to a twenty third aspect, the invention provides a supercapacitor having a non aqueous solvent system and an ESR at 50° C. of no more than 2.0, more preferably no more than 1.5, even more preferably no more than 1.4 times the ESR at 50° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0103] According to a twenty fourth aspect the invention provides a supercapacitor having a non aqueous solvent system and an ESR at −30° C. of no more than 13.7, more preferably no more than 8.3, even more preferably no more than 6.4 and most preferably no more than 3.5 times the ESR at 23° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0104] According to a twenty fifth aspect, the invention provides a supercapacitor having a non aqueous:solvent system and an ESR at −20° C. of no more than 4.4, more preferably no more than 3.6, even more preferably no more than 3.4 times the ESR at 23° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0105] According to a twenty sixth aspect, the invention provides a supercapacitor having a non aqueous solvent system and an ESR at 50° C. of no more than 1.6, more preferably no more than 1.3 times the ESR at 23° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0106] According to a twenty seventh aspect, the invention provides a supercapacitor having a non aqueous solvent system and an ESR at 85° C. of no more than 1.4, more preferably no more than 1.2, and most preferably no more than 1.1 times of the ESR at 23° C. of a supercapacitor of identical construction but which contains acetonitrile as sole solvent.
[0107] The supercapacitors of the present invention may have any or all of the relative performance properties of the tenth to twenty seventh aspects.
[0108] According to a twenty eighth aspect, the invention provides a method of selecting a solvent system for use in an electrical storage device including the steps of:
selecting a plurality of potential solvents; preparing a primary, binary, ternary or higher order mixture of said potential solvents, optionally adding an ion source; determining a property of said primary, binary, ternary or higher order mixture; preparing a phase diagram of said mixtures; and identifying a solvent mixture adapted to provide a predetermined value of said property.
[0113] Preferably, the binary, ternary or higher order mixture includes at least one high boiling high viscosity solvent and at least one low boiling low viscosity solvent.
[0114] Preferably, the binary, ternary or higher order mixture is a combination of a low viscosity solvent and one or more compatible high viscosity solvents.
[0115] Preferably the low viscosity solvent is a nitrile, most preferably acetonitrile.
[0116] Preferably the high viscosity solvent is one or more of a lactone, such as y butyrolactone, or an organic carbonate such as ethylene carbonate, propylene carbonate or derivatives thereof.
[0117] Preferably, the given parameter is one or more of boiling point, conductivity, viscosity or ESR at a predetermined temperature.
[0118] According to a twenty ninth aspect the invention provides a supercapacitor, preferably of a multilayer soft packaging laminate design, which has a mass loss of no more than 3% of the room temperature mass on sustained heating at 100° C., preferably a mass loss of no more than 2% of the room,temperature mass and even more preferably a mass loss of no more than 1% of the room temperature mass. Sustained heating is preferably a period in excess of 2 hours continuous use.
[0119] According to a thirtieth aspect the invention provides a supercapacitor, preferably of a multilayer soft packaging laminate design, which has a mass loss of no more than 2% of the room temperature mass on sustained heating at 95° C., preferably a mass loss of no more than 1% of the room temperature mass and even more preferably a mass loss of no more than 0.5% of the room temperature mass. Sustained heating is preferably a period in excess of 3 hours continuous use.
[0120] According to a thirty first aspect the invention provides a supercapacitor, preferably of soft packaging laminate design, which has a mass loss of no more than 0.5% of the room temperature mass on sustained heating at 90° C. and even more preferably zero mass loss on sustained heating at 90° C. Sustained heating is preferably a period in excess of 4 hours continuous use.
[0121] According to a thirty second aspect, the invention provides a supercapacitor having an extrapolated ESR at infinite electrolyte conductivity (ESR ∝ ) of no more than 325 mΩ cm 2 , more preferably no more than 189 mΩ cm 2 and most preferably no more than 147 mΩ cm 2 .
[0122] In another aspect the invention relates to a device incorporating an energy storage device of the present invention. Such devices include, but are not limited to devices such as digital wireless devices, for example, mobile telephones. Devices of the present invention also include computers, and related combination devices which may be networked conventionally or in a wireless manner. Other devices are in the form of an electrical vehicle or hybrid electrical vehicle. It will be appreciated that the devices of the present invention are especially suited to those applications where high temperature use is expected, but where design considerations would render bulky “can” type supercapacitors unsuitable.
[0123] The energy storage devices of the present invention maybe used, for example, with a GPRS communications module for a cellular telephone, a GSM module, a Mobitex module, 3G module, a PCMCIA card, a Compact Flash card, a communications card or device for a notebook computer, a laptop computer or a Tablet computer, a wireless LAN device such as a desktop or other computer or any other wireless device.
[0124] Most preferably, the device of the present invention is a supercapacitor used as part of a power source in a PCMCIA card, especially a modem or fax modem card.
[0125] Preferably, when the energy storage device of the present invention are used with communications modules or cards, they are in the form of a supercapacitor having a plurality of supercapacitive cells. The cells are preferably connected in series and even more preferably, the cells are contained within the same package, although the cells may be contained within separate packages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0126] FIG. 1 shows a graph of 1/boiling point against 1/viscosity for a range of solvents.
[0127] FIG. 2 shows a graph of conductivity against 1/viscosity for a range of solvents.
[0128] FIG. 3 shows a graph of ESR against 1/conductivity (as a function of TEATFB concentration at 23° C.) for Series Y standard test cells with acetonitrile.
[0129] FIG. 4 shows a graph of ESR against temperature for mono solvent systems for Series Y and Series X standard test cells.
[0130] FIG. 5 shows the relationship between conductivity and ESR for a Series X standard test cell with acetonitrile.
[0131] FIG. 6 shows a graph of ESR vs 1/conductivity (obtained by varying the temperature) for a Series X standard test cell with acetonitrile.
[0132] FIG. 7 collates FIGS. 6 and 3 to allow comparison of the concentration and temperature effects.
[0133] FIG. 8 shows lines of best fit for conductivity against temperature for three electrolyte systems, namely 1M TEATFB in 3AN:1.72GBL:EC, 3AN:2GBL:EC and AN.
[0134] FIG. 9 shows ESR against temperature for standard test cells with 1M TEATFB in 3AN:1.72GBL:EC (Series X and Z), 3AN:2GBL:EC (Series Z) and AN (Series X). The separator is nominally 50 μm thick.
[0135] FIG. 10 shows ESR against temperature for Series Z standard test cells having 1M TEATFB in 3AN:2GBL:EC and AN electrolytes. The separator is nominally 20 μm thick.
[0136] FIG. 11 shows ESR against 1/conductivity for standard test cells with 1M TEATFB in 3AN:1.72GBL:EC (Series X and Z), 3AN:2GBL:EC (Series Z) and AN (Series X). The separator is nominally 50 μm thick.
[0137] FIG. 12 shows ESR against 1/conductivity for Series Z standard test cells having 1M TEATFB in 3AN:2GBL:EC and AN electrolytes. The separator is nominally 20 μm thick.
[0138] FIG. 13 shows ESR verses temperature for a multiple layered electrode stack in a single cell and also for two of these cells connected in series to form a two cell device. The electrolyte used was 1M TEATFB in 3AN:1.72GBL:EC. The separator was nominally 50 μm thick.
[0139] FIG. 14 shows ESR verses 1/conductivity for a multiple layered electrode stack in a single cell and also for two of these cells connected in series to form a two cell device. The electrolyte used was 1M TEATFB in 3AN:1.72GBL:EC. The separator was nominally 50 μm thick.
[0140] FIGS. 15 to 26 show phase diagrams for electrolyte mixtures. The phase diagrams show the mole ratios of the solvent mixture. The property of that particular solvent mixture is represented in boldface text, in italics or underlined.
[0141] FIGS. 27 and 28 show thermogravimetric analysis of a multilayered soft packaging laminate supercapacitor cell with prior art electrolyte (acetonitrile). The cell in this figure takes the form of a multiple layered electrode stack.
[0142] FIGS. 29 and 30 show thermogravimetric analysis of a multilayered soft packaging laminate supercapacitor cell with an electrolyte of the present invention (3AN:1.72GBL:EC). The cell in this figure takes the form of a multiple layered electrode stack
[0143] FIGS. 31 and 32 show thermogravimetric analysis of a multilayered soft packaging laminate supercapacitor device with an electrolyte of the present invention.
[0144] FIG. 33 shows a contour plot of boiling points for AN:PC:GBL ratios.
DESCRIPTION
[0145] The present invention is described with reference to the supercapacitors developed by the present applicant and disclosed in detail in the applicants copending applications, for example, PCT/AU98/00406, PCT/AU99/00278, PCT/AU99/00780, PCT/AU99/01081, PCT/AU00/00836 and PCT/AU01/00553. It will be understood by those skilled in the art that the present application uses those supercapacitors and that in the present instance, the solvent is the variable of interest. However, it will also be appreciated by those skilled in the art that the electrolyte solutions of the present application will be equally applicable for use in other energy storage devices of different design.
[0146] Acetonitrile (AN) is widely used as the sole solvent component of electrolyte systems because it has a high dielectric constant (38 at 20° C.) and a low viscosity (0.369 cP at 20° C.). A 1M solution of tetraethylammonium tetrafluoroborate has a room temperature conductivity of 55 mS/cm, which is around 2-5 times better than can be attained using most other single component organic solvents.
[0147] Acetonitrile also has a low freezing point and relatively low viscosity, making it suitable for low temperature applications. However, acetonitrile boils at 82° C. which means that at or above this temperature it is necessary to contain the vapour, and additional challenges need to be met in respect of ensuring the mechanical integrity of any packaging of devices which use AN at or above this temperature.
[0148] A thermogravimetric analysis of a supercapacitor cell containing acetonitrile made without any special consideration to containing high pressure shows a sudden and irreversible weight loss at 83° C. In some applications, an upper temperature limit of 80-85° C. is unsatisfactory, and higher temperatures (up to 95° C. and above) are required for prolonged periods.
[0149] As mentioned, it is important that the electrolyte has as high a conductivity and as low a contribution to device ESR as possible. High conductivity can be achieved primarily by using a low viscosity (or, in practical terms, low boiling) solvent, although in order for high conductivity, it is also necessary for the solvent to have a good dielectric constant to enable it to dissolve ionic species.
[0150] As mentioned above, simply employing a single compound with a higher boiling solvent is not desirable for various reasons. While a number of higher boiling solvents are available with good dielectric constants, they are invariably significantly more viscous than lower boiling solvents. Further, high viscosity solutions do not exhibit appropriate conductivities until much higher temperatures (where the viscosity is reduced). Thus, while these high temperature solvents are capable of good conductance at high temperature, they have unsatisfactorily high ESRs at ambient or subzero temperatures. To illustrate the problem, at room temperature the conductivity of acetonitrile is around 55 mS/cm while that of γ-butyrolactone (GBL) is only around 18 mS/cm. Conductivity increases with temperature but the conductivity of γ-butyrolactone does not approach the room temperature conductivity of acetonitrile until the temperature reaches 130° C. To those skilled in the art, admixing the two would not appear to produce a solution to the problem as acetonitrile, which boils around 80° C. would be expected to fractionate out of the mixture long before a suitable conductivity of γ-butyrolactone was achieved. Surprisingly, in the present case, such fractionation did not occur.
[0151] In particular, the present applicant has found that solvent blends, such as a blend of a nitrile, a lactone and a carbonate, and in particular acetonitrile, γ-butyrolactone and propylene carbonate (PC) or a blend of acetonitrile, γ-butyrolactone and ethylene carbonate (EC) or a blend of acetonitrile, propylene carbonate (PC) and ethylene carbonate (EC) produce a ternary solvent that has good conductivity, (and consequently a suitably low ESR) over a good temperature operating range, with high stability at elevated operational temperature, such as 85° C.
[0152] Without wishing to be bound by theory, it is believed that this stability at elevated temperatures is due to association between the species, i.e. rather than being a mere admixture which undergoes fractionation of the lower boiling components as temperature increases, an association between the species means that the acetonitrile does not fractionate out of the mixture. The fact that no fractionation occurred leads to the hypothesis that acetonitrile forms complexes with the other solvent molecules in the solution which results in the elevation of the acetonitrile boiling temperature, i.e. the formation of a new complex with a higher boiling point.
[0153] A 1M Tetraethylammonium tetrafluoroborate solution in a mole ratio of 3 acetonitrile: 1.72-2 γ-butyrolactone:1 ethylene carbonate mixture performed unexpectedly well in the tests as is illustrated in the examples. This ternary mixture had a boiling temperature of 109° C. with no fractionation of acetonitrile around its boiling point as would have been expected.
[0154] Thermo gravimetric analysis of supercapacitor test cells and devices containing 3 acetonitrile: 1.72 γ-butyrolactone:1 ethylene carbonate showed that the weight of the material remained constant up to at least 103° C. before sample loss occurred. It was highly significant that no sample loss commenced immediately above 82° C., the boiling point of acetonitrile. Such an observation bears out the hypothesis of some intermolecular interactions taking place.
[0155] Further, qualitative analysis of samples containing the ternary system, but with a significant mole excess of acetonitrile showed some fractionation, indicating that beyond a certain point, there was no further opportunity for complexation of the acetonitrile.
[0156] Further investigations as to the mechanism of the temperature elevation without fractionation were conducted and in particular whether or not it involved some solvation of the ionic species in solution. Depending on the solvent and particular ionic species, the addition of a dissolved salt can generally increase boiling temperature by around 1-3° C. per mole of ionic species. For example, the boiling point of another preferred ternary solvent (2AN:0.86 GBL:EC) of the present invention was around 107° C. without the salt. Adding a salt to a concentration of 1 M gave a boiling point of around 108-113° C., an increase of up to 6° C. This corresponds to a rise of up to 3° C. per mole of ionic species which is within the expected,limits.
[0157] By contrast, the difference between the boiling point of the mixture and the boiling point of pure acetonitrile is around 25° C. There is strong evidence that the mixture is more than merely an admixture, but rather a solution in which there is an interaction between the species.
EXAMPLES
GENERAL PROCEDURE
[0158] In order to identify those solvent systems stable over an extended lifetime at elevated temperatures (≧85° C.), the following general procedure was adopted.
[0159] Dried, recrystallised TEATFB was used throughout. Solvents used in this experiment were obtained from Merck Germany with the highest quality available i.e. Selectipur® and were run through a chromatography column packed with about 10 cm of γ alumina. The moisture content in the final product was estimated by Karl Fischer titration as follows: GBL=10 ppm, PC=5 ppm, AN=2 ppm. EC was a solid and was not further purified. Once the salt was added, the mixture was shaken well until all salts were dissolved.
[0160] Where ratios of solvents were used, these refer to mole ratios.
[0161] Solutions of TEATFB were all 1 molar unless otherwise indicated. Where experiments are conducted on solvent only (eg, AN, or 2AN:0.86 GBL:EC) this is indicated in the text.
[0162] The solvent mixtures were prepared with final volumes between 30 to 40 ml which were sufficient for boiling point and conductivity tests.
[0163] The conductivity of these electrolytes were measured inside a dry nitrogen atmosphere in a glove box using a handheld ULTRAMETER (Model 6P) from Nyron L Company in accordance with the recommended procedure in the operating manual.
[0164] For boiling point determination, the sample vial was filled with about 20 ml of test electrolyte plus some boiling chips and heated rapidly (˜10° C./min) until the temperature reached ˜75° C., then reduced to a rate rise of about 2° C./min or less, with continued monitoring of the solution.
[0165] EC, being a solid at room temperature, was kept in a 50° C. environment to ensure it remained liquid at all times. Where EC was used in conjunction with other solvents in a binary or ternary mixture, the salt was added subsequent to the combining of the solvents.
[0166] Unless otherwise stated, a standard test cell of area 28 cm 2 was used to generate results. For the standard test cells, two carbon-coated electrodes were cut to a size of 28 cm 2 excluding terminals. The electrodes are cut such that they are 8 cm×3.5 cm. The terminals were approximately 4 cm long and were 2.5 cm from the corner along the longest edge. One electrode was folded in half such that the carbon was facing inwards. The second electrode was folded in half such that the carbon was facing outwards. This second electrode was encompassed in a membrane separator and the membrane-encased electrode was slid into the first electrode. Unless stated otherwise a 50 μm polyolefin membrane was used. Those skilled in the art will appreciate that both the materials and the thickness of the membranes can be varied considerably without effecting the overall functionality of the device. The carbon layers were facing each other with a separator in between. The device was assembled so that the terminals were both pointing in the same direction.
[0167] A multilayer soft packaging laminate was wrapped around the electrodes allowing the terminals to protrude to the outside of the packet. The packet was heat sealed leaving one end open. The cell was dried using heat and vacuum. The packet was filled with enough electrolyte to cover the electrodes and sealed. The sealed packet was pierced and taken to a tight vacuum. The packet was sealed again close to the electrode stack to complete the standard test cell.
[0168] Examples of electrode arrangements may be found in our copending applications PCT/AU01/01613 and PCT/AU01/01590, the contents of which are incorporated herein by reference.
[0169] The cell was then cycled between a low voltage and the voltage at which the cell was to be used. Electrical testing was then performed. ESR measurements were taken, at voltage as per the industry standard, which in the present case is 1.8V, at 1 kHz. Capacitance was measured using a discharge current of 0.2 A.
[0170] Where the following data is dependent upon the construction of the supercapacitor, such data is given as being either “Series X”, which has a nominal 4.5 μm carbon layer; “Series Z” which has a nominal 7.3 μm carbon layer thickness; “Series Y”, which has a nominal 10 μm carbon layer thickness; and “Series W” which has a 13.5 μm coating thickness. The density of the series is as follows: Series X—0.22 mg/cm 3 ; Series Y—0.33 mg/cm 3 ; Series W—1.12 mg/cm 3 and Series Z—0.35 mg/cm 3 . Because the series data relate to variations in the construction of the supercapacitor Series X data should only be compared with other Series X data and so on. Control data obtained for acetonitrile in all series enables the relative results to be standardised and compared. The cells which take the form of a multiple layered electrode stacks invariably used a coating thickness of nominally 6 μm and a density of approximately 0.35 mg/cm 3
[0171] Experimental errors in observed values have not been quoted here, although those skilled in the art will be familiar with the precision and accuracy with which such values are normally determined.
[0172] Descriptions of the construction of multilayered electrode stack devices are disclosed in our copending application PCT/AU01/01613, the contents of which are incorporated herein by reference. In the present case, the electrode area was 24.4 cm 2 .
[0173] The standard test cell, for a nominally 6 μm thick coating and nominally 50 μm thick separator membrane, has a volume in the order of 1.23×10 −6 m 3 and a weight of 1.76 g including the multilayer packaging laminate.
[0174] The standard test cell, for a nominally 6 μm thick coating and nominally 50 μm thick separator membrane, has a volume in the order of 3.03×10 −7 m 3 and a weight of 0.43 g neglecting the multilayer packaging laminate.
[0175] The cell comprised of a multiple layered electrode stack, for a nominally 6 μm thick coating and nominally 50 μm thick separator membrane, has a volume in the order of 8.62×10 −7 m 3 and a weight of 0.97 g including the multilayer packaging laminate.
[0176] The cell comprised of a multiple layered electrode stack, for a nominally 6 μm thick coating and nominally 50 μm thick separator membrane, has a volume in the order of 3.19×10 −7 m 3 and a weight of 0.39 g neglecting the multilayer packaging laminate.
[0177] The two cell device comprised of two multiple layered electrode stacks connected in series, for a nominally 6 μm thick coating and nominally 50 μm thick separator membrane, has a volume in the order of 1.72×10 −6 m 3 and a weight of 1.94 g including the multilayer packaging laminate.
[0178] The two cell device comprised of two multiple layered electrode stacks connected in series, for a nominally 6 μm thick coating and nominally 50 μm thick separator membrane, has a volume in the order of 6.37×10 −6 m 3 and a weight of 0.78 g neglecting the multilayer packaging laminate.
[0179] It will be obvious to those skilled in the art that altering the physical properties, including the density of the coating, the thickness of the coating, the density of the separator, the thickness of the separator and or the density of the multilayer soft packaging laminate or the thickness of the multilayer soft packaging laminate or the thickness or density of the current collector will alter the volume and thickness of the cells similarly.
[0000] 1. Mono Solvent Systems
[0180] As mentioned earlier, acetonitrile is an extremely useful electrolyte solvent. It has a very low viscosity and a very high dielectric constant. Both these attributes combine to make an acetonitrile electrolyte which has a very high conductivity. The downside of using acetonitrile as the electrolyte in a supercapacitor is the fact that it boils at around 80° C. which means that there are additional containment problems to address if the supercapacitor is to be used at high temperatures.
[0181] In order to identify an alternate solvent with a comparable conductivity, the parameters for likely mono solvent systems were established before focussing on binary and ternary solvent systems. Three different solvents were mixed with tetraethylammonium tetrafluoroborate up to saturation or 1M, which ever is the lesser. These mixtures were then purified in the usual method and tested in a variety of methods including electrical testing, in standard test cells, as well as conductivity measurements over a range of temperatures.
RESULTS
[0182] Three main electrolyte solvents were tested: γ-butyrolactone (GBL), propylene carbonate (PC) and ethylene carbonate (EC). Acetonitrile was also used as a control.
[0183] The relevant physical properties of the solvents in question are as follows:
Density Melting (g/cm 3 ) Viscosity Point/Boiling Dielectric at (cP) Solvent Point (° C.) Constant 20° C. at 25° C. Acetonitrile −46/82 38 (at 20° C.) 0.78 0.369 (AN) γ-butyrolactone −44/204-6 39 (at 25° C.) 1.13 1.17 (GBL) Propylene −48/242 65 (at 25° C.) 1.21 2.8 (20° C.) Carbonate (PC) Ethylene 35-8/247-9 95 (at 25° C.) 1.41 1.92 (40° C.) Carbonate (EC)
[0184] Acetonitrile (AN):
Acetonitrile Temperature (deg C.) Conductivity (mS/cm) 1M TEATFB −20 32.8 0 48.1 25 59.6 50 70.2 75 79.7
[0185] As mentioned in the introduction, conductivity, viscosity, temperature and ESR are related. FIG. 4 shows ESR versus Temperature for PC, GBL and AN. In order to illustrate the principle further, FIGS. 5 and 6 show plots of ESR against conductivity and ESR against 1/conductivity respectively for AN.
[0186] The following data was obtained in a standard test cell:
[0187] Series Y
ESR Capacitance (0.2 A) Electrolyte (mΩ)23° C. (F) 23° C. AN 1M TEATFB 25.1 0.72
[0188] Series X
ESR Capacitance (0.2 A) Electrolyte (mΩ)23° C. (F) 23° C. AN 1M TEATFB 20.5 0.52
[0189] γ-Butyrolactone (GBL): The saturation point for this liquid, with respect to tetraethylammonium tetrafluoroborate, is around 0.92M at room temperature (23° C.). The conductivity measurements over a range of temperatures is shown in the following table:
γ-Butyrolactone Temperature (Deg C.) Conductivity (mS/cm) 0.92M −5.6 9.0 0.1 10.5 23.6 16.9 85.2 33.2 131.0 51.0
[0190] It can be seen from this table that the conductivity of the solution does not rival the room temperature conductivity of 1M acetonitrile (55 mS/cm) until over 130° C. This is most likely due to the increased viscosity of the GBL as compared to AN. The test cells at room temperature (below) also show a proportionally higher ESR than the control.
[0191] Series Y
ESR Capacitance (0.2 A) (F) Electrolyte (mΩ) 23° C. 23° C. AN 1M TEATFB 25.1 0.72 GBL 0.92M TEATFB 62.1 0.70
[0192] Propylene Carbonate (PC): Propylene carbonate can solvate slightly more than one molar of tetraethylammonium tetrafluoroborate. The saturation limit is around 1.2M at room temperature. The conductivity data was found to be as follows:
PC 1M Temperature (Deg C.) Conductivity (mS/cm) −22.5 1.3 0 8.0 25 13.8 85 30.2 180 55.1
[0193] Like GBL, propylene carbonate does not have a conductivity anywhere near the room temperature conductivity of AN until it reaches 180° C. The averages for the ESR of the test cells were found to be:
[0194] Series Y
ESR Capacitance Electrolyte (mΩ) 23° C. (0.2 A) 23° C. AN 1M TEATFB 25.1 0.72 PC 1M TEATFB 65.4
[0195] Interestingly the dielectric constant of propylene carbonate is higher than acetonitrile (almost double in fact) which should allow it to dissociate more salt. While such a characteristic is desirable the main drawback with using propylene carbonate, which corresponds to the higher ESR, is its exorbitantly high viscosity: PC is over 7 times more viscous than AN. The main benefit with PC is its 242° C. boiling point.
[0196] Ethylene Carbonate (EC) is slightly different from the other solvent systems used in that it is a solid at ambient temperatures. Consequently, it was not possible to obtain data for EC alone at temperatures below about 35-40° C.
[0197] The ESR of Series X and Series Y cells is given in the following table and a plot of ESR against temperature is shown in FIG. 4 .
ESR at specified temp (mΩ) −20° C. 23° C. 50° C. 85° C. 1M TEATFB in AN 33.5 20.5 18.5 1M TEATFB in PC 293.9 65.4 40.0 0.92M TEATFB in GBL 62.1 44.1 EC Solid Solid
2. Binary Solvent System
[0198] Following a thorough analysis of the boiling points and conductivities of various combinations of acetonitrile (AN), ethylene carbonate (EC), γ-butyrolactone (GBL), and propylene carbonate (PC), binary mixtures of each were prepared to investigate their suitability for high temperature application.
[0199] The main binary systems investigated were those with a combination of a low boiling, non viscous liquid, and a higher boiling more viscous liquid. In particular, these were: AN:GBL, AN:0.86 GBL, AN:PC, and AN:EC
[0200] The electrolytes were made up as 1M (tetraethylammonium tetrafluoroborate) TEATFB solutions and underwent electrical performance and stability testing across a range of −20° C. to 95° C.
[0201] Control data for AN is given and those skilled in the art will readily appreciate that this value can be used to standardize the data between Series X, Series Y and Series Z and allow a direct comparison of the quantitative differences between the two data sets, should this be desired.
Conductivity Tested temp Boiling Point Solution (mS/cm) (° C.) (° C.) 0.86GBL:AN 31.3 29.0 108-110 GBL:AN 30.6 23.8 106 0.86GBL:2AN 38.1 26.4 97 GBL:2AN 36.9 23.0 97 1.72GBL:AN 25.9 26.9 125-126 2GBL:AN 24.8 23.0 121 PC:AN 27.0 26.2 112 PC:2AN 26.7 26.4 112 2PC:AN 21.3 27.3 131-132 PC:2.5AN 36.0 28.9 96 PC:3AN 37.7 29.4 92 EC:AN 28.5 26.2 110-113 EC:2AN 43.3 26.2 93 2EC:AN 28.5 27.1 113 EC:1.5AN 32.0 30.5 104
[0202] The ESR and Capacitance of supercapacitors incorporating the solvent systems of the present invention were investigated at 23° C. The control data and results are summarised below and are plotted on the phase diagrams and in FIG. 5 .
[0203] Series X (Control)
Capacitance (0.2 A) (F) Electrolyte ESR (mΩ) 23° C. 23° C. AN 1M TEATFB 20.5 0.52
[0204] Series Y (Control)
Capacitance (0.2 A) (F) Electrolyte ESR (mΩ) 23° C. 23° C. AN 1M TEATFB 25.1 0.72
[0205] Series Z (Control)
Capacitance (0.2 A) (F) Electrolyte ESR (mΩ) 23° C. 23° C. AN 1M TEATFB 19.4 0.74
[0206] Series X
Electrolyte ESR (mΩ) Capacitance (F) AN:0.86GBL 1M TEATFB 26.8 0.40
[0207] Series Z
Electrolyte ESR (mΩ) Capacitance (F) AN:GBL 1M TEATFB: 31.9 0.75
[0208] Series Z
Electrolyte ESR (mΩ) Capacitance (F) AN:0.86GBL 1M TEATFB 27.5 0.75
[0209] Series X
Electrolyte ESR (mΩ) Capacitance (F) AN:EC 1M TEATFB 35.9 0.38
[0210] Series X
Electrolyte ESR (mΩ) Capacitance (F) AN:PC 1M TEATFB 38.3 0.32
[0211] Series Y
Electrolyte ESR (mΩ) Capacitance (F) AN:PC 1M TEATFB 41.6 0.48
[0212] The results for the mixtures were plotted on phase diagrams, as shown in FIGS. 15 to 26 .
[0213] The ESR of various binary mixtures was measured at a range of temperatures, and the results are shown in the following table.
[0214] 1M TEATFB
ESR at specified temp (mΩ) Data Series Electrolytes: −20° C. 23° C. 85° C. Series X AN:0.86GBL 70.7 26.8 23.4 Series Z AN:0.86GBL 27.5 Series Z AN:GBL 65.1 31.7 21.7 Series X AN:EC 230.3 35.9 28.3 Series X AN:PC 38.3 Series Y AN:PC 41.6 27.3
[0215] The conductivity of AN:0.86GBL and AN:GBL solutions with 1M TEATFB was determined for a range of temperatures. The results are shown in the following table.
AN:0.86GBL Temperature (° C.) Conductivity (mS/cm) 1M TEATFB −30 13.4 −20 17.0 0 24.3 23 31.8 50 42.4 85 55.2 AN:GBL Temperature (° C.) Conductivity (mS/cm) 1M TEATFB −30 10.9 −20 13.3 0 19.8 23 30.6 50 39.4 85 52.5
Ternary Solvent Systems
[0216] A number of ternary solvent mixtures were prepared. The selection of the most likely solvent mixtures and ratios was in part based upon the results obtained from plotting the binary mixtures around the outer periphery of the triangular phase diagrams shown in the Figures.
[0217] The conductivity and boiling point of the electrolytes prepared are shown in the following table:
Solvent system Conductivity Tested temp (1M TEATFB) (mS/cm) (° C.) Boiling Point (° C.) PC:AN:0.86GBL 23.2 30.8 132 PC:AN:GBL 23.0 23.0 122-124 PC:2AN:0.86GBL 29.0 28.0 101-105 PC:2AN:GBL 28.3 24.2 106-108 3AN:0.86GBL:PC 32.4 31.0 104 3AN:GBL:PC 32.6 23.0 98 3AN:1.72GBL:PC 28.7 29.9 109 3AN:2GBL:PC 28.1 23.9 109 6AN:0.86GBL:2PC 35.1 28.9 98 6AN:GBL:2PC 34.3 23.0 96 EC:2AN:0.86GBL 30.5 27.7 108-113 EC:2AN:GBL 31.4 23.8 108 0.86GBL:EC:AN 25.6 29.9 130 GBL:EC:AN 26.4 23.0 118-120 3AN:1.72GBL:EC 30.5 32.1 109 3AN:2GBL:EC 30.9 23.7 107-110 3AN:0.86GBL:2EC 30.0 32.3 108-110 3AN:GBL:2EC 31.6 23.2 107 EC:AN:PC 22.4 27.8 106-107 PC:EC:2AN 28.3 29.3 108-110 3AN:EC:PC 31.7 28.7 101-104 4.5AN:2EC:PC 32.0 28.7 *104 6AN:2PC:EC 34.4 29.0 *100
[0218] Those entries in the table above marked with an asterisk exhibited some apparent fractionation before reaching the stated boiling point. Without wishing to be bound by theory, it is believed this was as a result of excess acetonitrile in those mixtures over and above that required to provide the true high boiling ternary mixture.
[0219] Boiling point elevation was also seen when AN was blended with different mole ratios of PC, EC and GBL. Without wishing to be bound by theory, these observations lead to the hypothesis that the AN may form complexes with the other solvent molecules in the solution which resulted in the elevation of acetonitrile boiling temperature. It was also noticed that the boiling temperature increased as the conductivity (at any given temperature) of the solution decreased.
[0220] From the results above, some promising systems were chosen for ESR and capacitance testing because they appear to have the temperature range and conductivities to meet ESR requirements across the temperature range from −30° C. to 95° C.
[0221] The following results were obtained with standard test cells.
[0222] Series X:
Solvent 23° C. System ESR (mΩ) Capacitance (F) 3AN:1.72GBL:PC 1M TEATFB 31.7 0.44 3AN:0.86GBL:2EC 1M TEATFB 30.3 0.46 2AN:PC:EC 1M TEATFB 34.5 0.42 2AN:0.86GBL:PC 1M TEATFB 34.0 0.41 2AN:0.86GBL:EC 1M TEATFB 31.5 0.43 3AN:1.72GBL:EC 1M TEATFB 30.5 0.42
[0223] Series Z:
Solvent 23° C. System ESR (mΩ) Capacitance (F) 3AN:2GBL:PC 1M TEATFB 33.8 0.71 3AN:GBL:2EC 1M TEATFB 31.6 0.70 2AN:GBL:PC 1M TEATFB 34.9 0.70 2AN:GBL:EC 1M TEATFB 31.6 0.72 3AN:2GBL:EC 1M TEATFB 26.7 0.72
[0224] A number of trials were also conducted using Series Y standard test cells. Series X and Series Y results are compared in the following table. All averages are based on 2-5 cells.
ESR and Capacitance 23° C. Capacitance Capacitance ESR (mΩ) (F) ESR (mΩ) (F) Electrolyte: Series Y Series Y Series X Series X 2AN:0.86GBL:EC 41.4 0.8 31.5 0.48 Average AN:PC:0.86GBL 48.5 0.78 Average:
[0225] Series W and Series Z results for standard test cells are compared in the following table. Averages are based on results from 5 cells.
ESR and Capacitance 23° C. ESR (mΩ) Capacitance (F) ESR (mΩ) Capacitance (F) Electrolyte: Series W Series W Series Z Series Z 2AN:GBL:EC 30.0 1.13 31.6 0.72 AN:PC:GBL 39.1 1.32 32.8 0.70
[0226] The ESR of the ternary mixtures were measured at varying temperatures. The results are the average of 3-5 standard test cells in Series X and Series Z and are shown in the tables below and in FIG. 8 .
[0227] Series X:
ESR at specified temp (mΩ) Solvent System −30° C. −20° C. 23° C. 50° C. 85° C. 2AN:0.86GBL:EC 135.0 74.5 31.5 27.1 26.3 2AN:0.86GBL:PC 187.9 77.9 34.0 26.4 25.3 2AN:PC:EC 149.2 90.9 34.5 29.8 28.5 3AN:1.72GBL:EC 130.6 70.6 30.5 26.0 25.5 3AN:0.86GBL:2EC 280.1 73.8 30.3 26.4 24.6 3AN:1.72GBL:PC 170.4 73.1 31.7 26.9 24.6
[0228] Series Z:
ESR at specified temp (mΩ) Solvent System −30° C. −20° C. 23° C. 50° C. 85° C. 2AN:GBL:EC 85.64 74.05 35.05 32.83 23.3 2AN:GBL:PC 89.79 59.02 34.79 33.59 22.3 3AN:2GBL:EC 64.3 53.8 26.7 22.5 20.9 3AN:GBL:2EC 83.80 70.10 31.57 29.72 23.1 3AN:2GBL:PC 96.46 73.15 32.71 31.66 22.28
[0229] The ESR of the ternary mixtures at varying temperatures for Series X and Series Z were adjusted for geometric area and a value of ESR multiplied by square cm of current collector (ESRx28 cm 2 )at different temperatures was obtained and is shown below in the table.
[0230] Series X:
Boiling Point Solvent ESR × Area at specified temp (mΩ cm 2 ) (° C.) System −30° C. −20° C. 23° C. 50° C. 85° C. 108-113 2AN: 3763 2117 862 784 706 0.86GBL:EC 101-105 2AN: 5253 2195 941 706 706 0.86GBL:PC 108-110 2AN:PC:EC 4155 2509 941 862 784 109 3AN: 3684 1960 862 706 706 1.72GBL:EC 108-110 3AN: 7840 2038 862 706 706 0.86GBL: 2EC 109 3AN: 4782 2038 862 784 706 1.72GBL:PC
[0231] Series Z:
Boiling Point Solvent ESR × Area at specified temp (mΩ cm 2 ) (° C.) System −30° C. −20° C. 23° C. 50° C. 85° C. 108 2AN:GBL: 2489.2 2113.4 1012.6 907.2 637.1 EC 107-110 3AN:2GBL: 1800.4 1506.4 747.6 630 585.2 EC 107 3AN:GBL: 2230.8 1876.7 901.7 821.1 606.8 2EC 109 3AN:2GBL: 2812.5 2097.9 945.4 880.0 619.3 PC
[0232] The ESR of the ternary mixture was compared with the ESR of acetonitrile at a range of temperatures. In this way, the relative performance of the mixtures can be evaluated in a manner independent of device construction. The table below shows the ratio of the ESR of a ternary electrolyte device to the ESR of a corresponding acetonitrile electrolyte device, where both devices are at the temperature specified in the table. The ratio for embodiments using a binary electrolyte is also given. For reference, the absolute value of the ESR of the AN control device was 38.0 mΩ at −30° C., 33.5 mΩ at −20° C., 20.5 mΩ at 23° C. and 18.5 mΩ at 50° C. for series X. For the series Z device, the absolute value of the ESR of the AN control device was 35.2 mΩ at −30° C., 31.2 mΩ at −20° C., 19.4 mΩ at 23° C. and 16.4 mΩ at 50° C.
[0233] Series X:
Boiling Point Solvent ESR of ternary/ESR of AN (° C.) System −30° C. −20° C. 23° C. 50° C. 108-113 2AN:0.86GBL:EC 3.5 2.2 1.5 1.5 101-105 2AN:0.86GBL:PC 4.9 2.3 1.7 1.4 108-110 2AN:PC:EC 3.9 2.7 1.7 1.6 109 3AN:1.72GBL:EC 3.4 2.1 1.5 1.4 108-110 3AN:0.86GBL:2EC 7.4 2.2 1.5 1.4 109 3AN:1.72GBL:PC 4.5 2.2 1.5 1.5 108-110 AN:0.86GBL 2.1 1.2
[0234] Series Z:
Boiling Point Solvent ESR of ternary/ESR of AN (° C.) System −30° C. −20° C. 23° C. 50° C. 108 2AN:GBL:EC 2.4 2.4 1.8 2.0 106-108 2AN:GBL:PC 2.8 2.5 1.8 2.0 107-110 3AN:2GBL:EC 2.0 2.2 1.6 1.7 107 3AN:GBL:2EC 2.2 2.1 1.6 1.7 109 3AN:2GBL:PC 2.8 2.4 1.7 1.8 106 AN:GBL 2.4 2.1 1.6 1.8
[0235] It is not possible to compare the ESR of ternary electrolytes against AN at temperatures much in excess of the boiling point of AN. However, in order to be able to compare the relative performances of all the ternary electrolytes (and the AN:0.86GBL, and AN:GBL binary mixtures) at elevated temperatures, they have been compared in the following tables against the ESR of AN at room temperature for series X (where the absolute value of the ESR of the AN control device at room temperature was 20.5 mΩ) and series Z (where the absolute value of the ESR of the AN control device at room temperature was 19.4 mΩ).
[0236] Series X:
Boiling Point Solvent ESR of ternary/ESR of AN @ room temp (° C.) System −30° C. −20° C. 23° C. 50° C. 85° C. 108-113 2AN: 6.6 3.6 1.5 1.3 1.3 0.86GBL:EC 101-105 2AN: 9.2 3.8 1.7 1.3 1.2 0.86GBL:PC 108-110 2AN:PC:EC 7.3 4.4 1.7 1.5 1.4 109 3AN: 6.4 3.4 1.5 1.3 1.2 1.72GBL:EC 108-110 3AN: 13.7 3.6 1.5 1.3 1.2 0.86GBL: 2EC 109 3AN: 8.3 3.6 1.5 1.3 1.2 1.72GBL:PC 108-110 AN: 3.4 1.2 1.1 0.86GBL
[0237] Series Z:
Boiling Point Solvent ESR of ternary/ESR of AN @ room temp (° C.) System −30° C. −20° C. 23° C. 50° C. 85° C. 106-108 2AN:GBL: 5.1 4.0 1.8 1.6 1.2 PC 106-108 2AN:GBL: 5.1 4.0 1.8 1.6 1.2 PC 107-110 3AN:2GBL: 3.5 3.5 1.6 1.5 1.1 EC 107 3AN:GBL: 4.0 3.4 1.6 1.5 1.1 2EC 109 3AN:2GBL: 5.0 3.7 1.7 1.6 1.1 PC 106 AN:GBL 4.3 3.2 1.6 1.5 1.2
[0238] Trials of the 3AN:1.72GBL:EC and 3AN:2GBL:EC ternary mix electrolytes demonstrated desirable ESR's across all temperature ranges. Most importantly, these cells appear to be quite stable at temperatures above 85° C.
[0239] The relationship between conductivity and temperature for AN and 3AN:1.72GBL:EC and 3AN:2GBL:EC is shown in FIG. 8 . The continuing relationship between conductivity and ESR can be seen to continue smoothly to temperatures in excess of 100° C.
[0240] FIG. 8 demonstrates the suitability of the solvent for use at temperatures in excess of those attainable for acetonitrile, as well as illustrating the low ESR values which are attained using the ternary mixtures of the present invention. It is notable that the solvent mixtures of the present invention provide ESR's at high temperature that are similar to the ESR's which can be obtained from AN at room temperature.
[0241] FIG. 9 Shows ESR against temperature while FIG. 11 shows 1/conductivity against ESR. The deviation in FIG. 9 at elevated temperatures is believed in that case to be due to a decrease in porosity of the separator at above 90° C. A decrease in porosity results in an increase in the resistivity of the separator.
[0242] In combination, FIGS. 8 to 11 illustrate that the solvent mixture of the present invention actually behaves in the same manner as a single solvent. Fractionating systems, with non-interacting components, would not provide the seamless electrochemical behaviour over such a wide temperature range and especially over a temperature range which includes the boiling point of AN, a major component of the mixture.
[0243] When measured in a 28 cm 2 test cell, ESR and temperature for the high temperature electrolyte 3AN:1.72GBL:EC were found to be related by the following equation:
ESR =((1044.3/(0.3948*( T )+25.852))+6.5178) [50 μm Separator]
ESR =((777.58/(0.3948*( T )+25.852))+6.741) [50 μm Separator, series z )
ESR =((649.32/(0.3948*( T )+25.852))+8.7202) [20 μm Separator]
[0244] Where the, temperature T is in degrees Celsius and the ESR is in mΩ.
[0245] The relationship between ESR and temperature for AN (calculated) was also quantified and found to be:
ESR =((1002.4/(0.4461*( T )+45.223))+5.2336) [50 μm Separator]
ESR =((673.91/(0.4461*( T )+45.223))+6.7856) [20 μm Separator]
[0246] The equations were derived by plotting conductivity versus temperature and the inverse of conductivity versus ESR for each of the two solvents. A straight line fit was placed though each data set. The lines of best fit can be seen in FIGS. 8 and 11 . The R 2 values for the curve fit was from about 0.96 to in excess of 0.99. The linear equations were then equated using the assumption that the conductivities are equal at any given temperature. The formula was then rearranged so as to be given in terms of ESR vs. temperature. The ESR can then be multiplied by the area of the smallest opposed electrode (or the area of mutual overlap between electrodes, if there is some offset) to give a value of ESR cm 2 . The more general equation is written thus:
ESR =(((1044.3/(0.3948*( T )+25.852))+6.5178)*28) [50 μm Separator]
ESR =(((777.58/(0.3948*( T )+25.852))+6.741)*28) [50 μm Separator, Series Z]
ESR =(((649.32/(0.3948*( T )+25.852))+8.7202)*28) [20 μm Separator]
ESR =(((1002.4/(0.4461*( T )+45.223))+5.2336)*28) [50 μm Separator]
ESR =(((673.91/(0.4461*( T )+45.223))+6.7856)*28) [20 μm Separator]
where the units for the above equations are: mΩ cm 2
[0247] The plot in FIG. 11 can also be used to extrapolate an ESR value at a point where 1/conductivity equals zero, ie ESR at infinite conductivity. Using the lines of best fit from FIG. 11 , for the AN series X line an ESR at infinite conductivity, ESR ∞ =5.2336 mΩ, or when adjusted for area, 147 mΩ cm 2 . Similarly, for AN series Y ( FIG. 7 ), ESR ∞ =6.823 mΩ, or when adjusted for area, 191 mΩ cm 2 . The ESR ∞ from the 3AN:1.72GBL:EC line was 6.741 mΩ, or when adjusted for area, 189 mΩ cm 2 . ESR ∞ is a useful parameter for comparing devices.
[0248] Similar equations can be constructed for other electrolyte systems, and for differing cell constructions. For example, FIGS. 7, 9 , 11 , 13 and 14 illustrate differences in observed values which are effected by supercapacitor construction.
[0249] For example, in a standard test cell as disclosed above, the variation in separator thickness attributed to moving between a 20 μm separator and a 50 μm separator.
50 μm Separator Electrolyte Equation 1M AN ESR = (((1002.4/(0.4461 * T + 45.223)) + Series X 5.2336) * 28)mΩ cm 2 1M 3AN:2GBL:EC ESR = (((646.94/(0.4009 * T + 22.646)) + Series Z 8.8613) * 28)mΩ cm 2 1M 3AN:1.72GBL:EC (1) ESR = (((777.58/(0.3948 * (R4) + 25.852)) + (1) Series Z 6.741) * 28) mΩ cm 2 (2) Series X (2) ESR = (((1044.3/(0.3948 * (N4) + 25.852)) + 6.5178) * 28) mΩ cm 2
[0250]
20 μm Separator
Electrolyte
Equation
1M AN
ESR = (((673.91/0.4461 * T + 45.223)) +
Series Z
6.7856) * 28) mΩ cm 2
1M 3AN:2GBL:EC
ESR = (((501.19/(0.4009 * T + 22.646)) +
Series Z
9.9452) * 28) mΩ cm 2
1M 3AN:1.72GBL:EC
ESR = (((649.32/(0.3948 * (B4) + 25.852)) +
Series Z
8.7202) * 28) mΩ cm 2
[0251]
1M 3AN:1.72GBL:EC
Multiple Layered Electrode Stack Cells
Single cell:
ESR = (((1051.2/(0.3948 * (T) + 25.852)) +
13.282) * 24.4) mΩ cm 2
Two cells connected in
ESR = (((2045/(0.3948 * (T) + 25.852)) +
series:
13.009) * 48.8) mΩ cm 2
[0252] The boiling point of the electrolyte with 3AN:1.72GBL:EC or 3AN:2GBL:EC ternary solvent system was found to be significantly higher than that of AN alone. This electrolyte system also had good conductivity at the high and low ends of the temperature range of interest.
[0253] Based on the boiling point and performance in the test cell, an extensive analysis of the results revealed that the 1M TEATFB in 3AN:1.72GBL:EC—3AN:2GBL:EC was the preferred choice and this electrolyte solution was prepared to use in further testing.
[0254] By way of example, the following shows the method of calculation of the actual values used for the production of electrolyte as follows:
3 AN : 1.72 GBL : EC ≡ 3 × 41.05 g AN ( 1 Molar TEATFB ) : 1.72 × 86.09 g GBL ( 0.92 Molar TEATFB ) : 88 g EC ( 0 Molar TEATFB ) = 123.15 g AN : 148.08 g GBL : 88 g EC Total volume ~ 352.6 ml
[0255] Extra salt (TEATFB) added ˜15.876 g to make total salt concentration in mixture to 1 Molar TEATFB.
[0256] The moisture in this electrolyte was removed by putting approximately 100 g of γ alumina into this electrolyte and stirring well for one minute. The alumina was allowed to settle before being filtered out.
[0257] The final moisture found in the electrolyte was measured through Karl Fischer titration to be ˜16 ppm.
STABILITY RESULTS
[0258] The stability of multilayer soft packaging laminate devices of the present invention was tested by thermogravimetric analysis in a DMT-Thermo Balance under a flowing air atmosphere. For this test the cells take the form of a multiple layered electrode stacks.
[0259] Temperature was ramped at 0.1° C. per minute from ambient temperature.
[0260] The TGA shows the acetonitrile-only capacitors venting electrolyte solvent occurs between 83° C. and 86° C., see FIGS. 27 and 28 which show the TGA results, including temperature and weight loss profiles. By contrast, the supercapacitor cells, FIGS. 29 and 30 , and devices, FIGS. 31 and 32 , of the present invention having 3AN:1.72GBL:EC solvent systems showed no loss until over about 100° C.
[0261] In combination with the low ESR over a wide temperature range, the TGA stability demonstrates the suitability of the solvents systems of the present invention to provide stable devices with desirable power windows over a wide temperature range.
SUMMARY
[0262] As stated earlier, the objective of the present applicants was to determine an electrolyte which would be stable at elevated temperatures whilst retaining a usable ESR at lower temperatures (at least −20° C.). Initially this was thought to be unrealisable when using acetonitrile, as the boiling point of acetonitrile is only 82° C. Trials were performed and an unusual and unprecedented trend was seen—devices with mixtures of acetonitrile managed to survive a period of time at temperatures greater than or equal to 85° C. Apparently, a boiling point elevation phenomenon was being achieved.
[0263] There are two non-limiting theories on how this boiling point elevation could be realised. The first is that the elevation is a manifestation of the effect of salt in a solution. This is a well-established theory. The boiling point elevation due to salt is generally of the range of ˜1-3° C. per mole of ionic species in solution. The second explanation is that there is complexation or association between the solvents which leads to an increase in boiling point.
[0264] An experiment to distinguish between these explanations was conducted using one mixture with and without salt. Select results have been reproduced below.
Solution Boiling Point ° C. 2AN:0.86GBL:EC + 1M TEATFB 108-113 2AN:0.86GBL:EC (Solvent only) 107 AN (solvent only) 82
[0265] It can be seen from the results above that the effect of adding salt to the 2AN:0.86GBL:EC mixture is to increase boiling point by about 1-6° C. That is up to 3° C. per mole of ionic species. This is within the theoretical limits of what has previously been seen on the addition of salt.
[0266] By contrast the difference between the mixture of 2AN:0.86GBL:EC and the pure acetonitrile is 25° C. If the mixture is not an actual solution then one would expect to see some fractionation at 82° C. The fact that this is not seen implies that there is indeed a solvation effect on the acetonitrile.
[0267] Hence it implies that, whilst the addition of salt does raise the boiling point somewhat, the main boiling point elevation is due to the mixture effect.
[0268] While the invention has been illustrated with TEATFB, any other soluble salts may be used, eg Lithium, Sodium, Potassium salts and the like. The following table shows the boiling point elevations observed in a 3AN:2GBL:EC mixture incorporating alternative electrolyte salts.
[0269] Boiling Point of Alternative Salts in 3AN:2GBL:EC
Boiling Salt in 3AN:2GBL:EC point (° C.) Solvent only 104-106 1M Tetrabutylammonium Perchlorate 107 1M Tetrabutylammonium Tetrafluoroborate 105-107 1M Tetrabutylammonium Hexafluorophosphate 107 1M Triethylmethylammonium Tetrafluoroborate 108 0.5M Lithium Tetrafluoroborate 106
[0270] The ternary phase diagrams summarise the results of room temperature conductivity, room temperature ESR, ESR at low temperatures and boiling point elevation for solvent mixtures of acetonitrile, propylene carbonate and ethylene carbonate; acetonitrile, propylene carbonate and γ-butyrolactone; and acetonitrile, ethylene carbonate and γ-butyrolactone.
[0271] FIG. 33 shows how the trends in a value of a particular property, eg boiling point, may be evaluated. By creating a “contour plot” in which experimental date of equal value (ie equal boiling point) are joined, it becomes possible to predict other intermediate solvent compositions which may have that boiling point, or determine which other compositions may have a suitable boiling temperature. While this has been exemplified for boiling point elevation in AN:PC:GBL, those skilled in the art will appreciate that it can be applied equally to other solvent systems, and to other properties which depend upon the composition of the electrolyte, such as ESR and conductivity.
[0272] The ternary phase diagrams clearly show that the attempt to find a high temperature electrolyte is a trade off between high boiling point/high viscosity (and resultant low conductivity) on the one hand and high conductivity with a low boiling point on the other. Unfortunately the ultra high temperature electrolytes have low conductivity because they have a high viscosity, as discussed in the introduction and shown in FIGS. 1 to 3 .
[0273] The unexpected synergy of the solvent components, apparently as a result of complexation, allows for the selection of electrolyte solvents which have a better performance profile over a wide range of components than would be predicted from looking at the component solvents alone.
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The invention relates to energy storage devices such as capacitors and supercapacitors and non-aqueous solvent systems suitable for use as an electrolyte solvent therein. Devices incorporating the solvent system are suitable for use in, for example, wireless devices or automotive applications at high temperatures with minimal, if any mass loss. The solvent system has at least one low boiling component (preferably a nitrile, eg acetonitrile) at least one high boiling component compatible with said low boiling component (preferably lactones, eg γ-butyrolactone and/or organic carbonates eg ethylene carbonate or propylene carbonate); and wherein the components are selected in an amount such that said non-aqueous solvent system does not boil at the boiling point of the low viscosity solvent alone but has a boiling point greater than said low viscosity solvent alone.
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FIELD OF THE INVENTION
[0001] The invention relates to a method of making metallized plastic moldings and use of the moldings thus made.
SUMMARY OF THE INVENTION
[0002] A method of making a plastic molding is disclosed. The multi-step method entails applying a metallic layer 20 to 150 nm thick to a translucent plastic film having a thickness of 50 to 750 μm, removing part of the metallic layer, and applying to the metallized side of the film an adhesive layer 5 to 50 μm in thickness to obtain a product, and injection molding from the reverse (back-molding) the product with a translucent thermoplastic. The plastic molding thus made is suitable for the preparation of keys, fiftings, trim strips, reflectors, keyboards, casings, shields, advertising panels and packaging items.
BACKGROUND OF THE INVENTION
[0003] Plastic moldings which have a metallic gloss in addition to the usual decoration (for example handwritten words or flourishes, logos) are made by printing pre-fabricated metallized films then shaping them and back-spraying them with a plastic. Alternatively translucent plastic films are printed first then metallized. They are shaped thereafter and a protective layer is optionally applied to the metallic layer. These processes are carried out, for example, to produce plastic parts for cars, such as hub covers etc. They have the disadvantage that parts thus produced are not translucent owing to the metallic layer, and hence transmitted light methods cannot be used on those parts.
[0004] The problem addressed by the invention was therefore to provide a method enabling plastic moldings with a metallic gloss and other conventional decorative effects to be produced in a technically simple manner. The parts thus produced must also enable transmitted light technology to be used.
[0005] This problem has been solved by the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0006] The subject of the invention is a method of making a plastic molding which is characterized in that
[0007] a) a metallic layer from 20 nm to 150 nm thick is applied to a translucent plastic film from 50 μm to 750 μm thick,
[0008] b) the metallic layer on the metallized film of a) is partly removed,
[0009] c) an adhesive layer from 5 μm to 50 μm thick is thereupon applied to the metallized side of the film,
[0010] d) a printed or non-printed, translucent plastic film from 50 μm to 750 μm thick is then optionally laminated onto the adhesive layer of c),
[0011] e) a decorative layer from 3 μm to 40 μm thick is optionally then applied to the film of d) or the layer of c),
[0012] f) the product of c), d) or e) is optionally shaped and
[0013] g) the product of f) is finally injection-molded with a translucent thermoplastic.
[0014] In the method of the invention a metallic layer is applied to a translucent plastic film. The metallic layer is preferably applied by the so-called PVD (physical vapour deposition) process or the CVD (chemical vapour deposition) process. Alternatively the layer may be applied preferably by transfer metallization (see for example Joachim Nentwig, Kunststoff-Folien 2000, Carl Hanser Verlag, Munich, Vienna). The metals used are typically aluminium, chromium, silver, nickel and gold.
[0015] The metallic layer is thereupon removed from the desired places/areas of the plastic film. This is preferably done by means of a laser beam (see for example Gottfried W. Ehrenstein, Stefan Stampfer, 3D-spritzgegossene Formteile mit strukturiertem Leiterbild, Spritzgieβen 2000 - Internationale Jahrestagung [3D injection molded parts with a structured printed circuit pattern, Injection Molding 2000 - Annual International Conference], VDI-Verlag, 2000). The metallic layer may alternatively be partly removed, for example, by etching. If lasers are used for partial removal of the metallic layer step b) [partial removal of the metallic layer] may preferably take place after step g). Laser beam removal of the metallic layer may likewise take place after step c), d), e) or f). The thickness of the layer is normally in the nanometer range. The metallic layer is removed by the laser beam at the point where the beam strikes it, thereby creating an area through which light may, if so desired, pass by transmitted light (back-light) technology.
[0016] The adhesive layer is preferably applied to the metallized side of the film by screen printing. It may alternatively be applied with a doctor blade or by spraying. Its function is also to protect the metallic layer. Heat-activated polyurethane adhesives are preferably employed, as described for example in “Adhesion-Kleben und Dichten” by Dr G Festel, Dr A Proβ, Dr H Stepanski, Dr H Blankeheim, Dr R Witkowski, Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, Wiesbaden.
[0017] A printed or non-printed, translucent plastic film is thereupon optionally laminated onto the adhesive layer. A colored film may alternatively be used. Such a film can prevent or reduce loss of gloss in the metallic layer. Loss of gloss may occur during injection-molding(back-molding) at high temperatures. Lamination is preferably carried out at temperatures below the softening point of the film.
[0018] A decorative layer is then optionally applied. This is preferably done by screen printing. However application may alternatively be by offset, gravure, transfer or digital printing. The inks employed for the purpose should be translucent.
[0019] Shaping is then carried out. The so-called “high-pressure forming” process is preferably used, as described for example in DE-A 3 844 584. The film is preferably shaped below its softening temperature, so that the gloss of the metallic layer is not adversely affected.
[0020] Other methods are mechanical shaping and hydro-forming. If the geometry of the part permits (for example if a flat part is only slightly curved), shaping may be effected by the pressure of the thermoplastic during back-spraying, so that the additional shaping step may be omitted. After the shaping step protruding residual pieces may be removed, preferably by punching. Alternatively they may be removed by laser beam cutting, water jet cutting or milling.
[0021] The part is finally injection-molded from the reverse with a translucent thermoplastic.
[0022] The plastic moldings made by the method of the invention are used as keys, switches and fittings, particularly in the motor vehicle field and the electronics field, as trim strips, particularly in the vehicle exterior field, as reflectors particularly for lamps and headlights, as keyboards and casings particularly for telephones and mobile phones, as shields and keys particularly for household appliances, as advertising panels and as packaging items and as identification card
[0023] The invention is further illustrated but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
EXAMPLE
[0024] a) Metallizing a polycarbonate film (Makrofol® DE1-1C, 175 μm from Bayer AG) with aluminium.
[0025] The film was subjected to preliminary plasma treatment to increase adhesion of the metallic layer to the film. The aluminium was applied in a thickness of 80 nm by the PVD process (direct metallization). Metallization was carried out on a Heraeus-Leibold metallizing plant.
[0026] b) Removal of the Al layer in selected areas by laser Precision removal of the Al layer was carried out with a Rofin Sinar “Marker Power Line 60” laser plant.
[0027] Trial set-up:
Laser medium: Nd YAG Capacity: 60 watt Current: 8.5 A Wavelength: 1064 nm Pulse frequency: 4.1 kHz Feed speed: 200 mm/sec
[0028] c) Application of an adhesive layer
[0029] Adhesive “Aquapress® ME” produced by Pröll was applied by screen printing. Printing was carried out three times. The polyester fabric screen used had 100 threads per cm. When the printed films had been dried the thickness of the adhesive layer was 20 μm.
[0030] d) Additional film
[0031] A polycarbonate film 100 μm thick (Makrofol® DE1-4, 175 μm from Bayer AG) was laminated onto the product of c). Lamination took place at a film temperature of 90° C. and an application pressure of 4 bar.
[0032] e) Decorative layer
[0033] The translucent “Noriphan® HTR” ink system produced by Proll was applied by screen printing. Printing was carried out once. The fabric screen made of polyester had 100 threads per cm. When the printed film had dried the thickness of the ink layer was 6 μm.
[0034] f) The product from e) was shaped by high-pressure forming and the protruding residual pieces were cut off. The product temperature was approx. 80° C. and the mold temperature approx. 75° C.
[0035] g) The shaped product from f) was injection-molded with Makrolon® 2400 (polycarbonate from Bayer AG). The material temperature was 290° C. and the mold temperature 60° C.
[0036] Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
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A method of making a plastic molding is disclosed. The multi-step method entails applying a metallic layer 20 to 150 nm thick to a translucent plastic film having a thickness of 50 to 750 μm, removing part of the metallic layer, and applying to the metallized side of the film an adhesive layer 5 to 50 μm in thickness to obtain a product, and injection molding the product with a translucent thermoplastic. The plastic molding thus made is suitable for the preparation of keys, fittings, trim strips, reflectors, keyboards, casings, shields, advertising panels and packaging items and identification cards.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from French Patent Application No. 1157355 filed on Aug. 16, 2011, the entire content of which is incorporated herein by reference.
FIELD
[0002] The present invention relates to an activation apparatus for a passive ejector valve for improving the pressurisation of an aircraft turbojet engine system. An aspect thereof is essentially to optimise the function of such an ejector valve. The field of the invention is generally that of aircraft turbojet engines, and more precisely that of controlling the turbojet engines for the purpose of ensuring that the chambers inside the turbojet engines under consideration are liquid-tight.
BACKGROUND
[0003] A significant safety factor to be considered for systems that hold oil is that chambers inside the turbojet engines should be completely liquid-tight. Generally, the liquid-tight property of the chambers in turbojet engines is established by ensuring that a pressure difference is maintained between the outside of the chamber and the inside of the chamber at sealing limits of said chamber; the pressure difference should be such that the pressure inside the chamber is lower than the pressure outside the system by at least a value determined in advance.
[0004] As is shown in FIGS. 1 and 2 , a jet pump system 102 is currently used to pressurise oil chambers in a turbojet engine 101 , for example the LEAP-X®. Such a jet pump system, 102 , also called an ejector or eductor, is a device that enables the pressure in a chamber to be improved when turbojet 101 is operating at low speed, while still ensuring that the pressure differential specifications at the chamber sealing limits are preserved. For this purpose, in the case of the LEAP-X® for example, ejector 102 draws in air at pressure P 28 (P 28 is the intake plan on the LEAP-X®, not generic), typically via a high pressure compressor 104 of turbojet 101 and mixes it with oil-free air 105 coming from chamber 103 at the centre vent tube. This supplementary air is injected by ejector 102 and creates an aspiration effect inside chamber 103 , thus leading to a fall in pressure inside chamber 103 itself, and consequently a greater pressure differential at the sealing limits of chamber 103 that is being analysed. This device is necessary for the limits when turbojet 101 is running slowly when the pressure levels inside and outside the chamber are close to one another as well as close to the ambient pressure; it is therefore desirable to know the pressure differential that is needed.
[0005] Accordingly, in order to prevent oil leaks at low turbojet speeds, it is desirable to activate ejector 102 to ensure that a given pressure differential is maintained at the sealing limits of chamber 103 . However, the extraction of air from inside high-pressure compressor 104 by means of ejector 102 is not neutral in terms of the performance of the turbojet, particularly during high-speed phases of the turbojet; this is why pressurisation of the chambers is most often maintained with regard to the exterior/interior pressure differential without the use of an ejector during high-speed phases.
[0006] It is therefore desirable to provide for controlled use of an ejector 102 to ensure that it is not used all the time. Accordingly, in the prior art use of control valve 106 for ejector 102 is provided, which is capable of switching from an on state, in which the pulsed air is directed into the centre vent tube, as the valve is in a completely open position, to a blocking state, in which no pulsed air is sent into the centre vent tube by the ejector because valve 106 is in a completely closed position.
[0007] The valve is designed for passive operation—it is called a passive valve—, that is to say the opening/closing movement of the valve, as shown in FIG. 3A , is controlled solely by a pressure differential that actuates it when the pressure differential reaches a trigger threshold DP 0 , this pressure differential being the difference in pressure between the P 28 pressure drawn from high-pressure compressor 104 and the pressure surrounding the valve, or ambient pressure Pamb.
[0008] As is shown in FIG. 3B , the principle of operation of passive valve 106 includes a hysteresis 301 that offsets the operations of opening/closing the valve.
[0009] FIG. 4 represents a mapping 401 of different situations to which the passive valve may be exposed. Accordingly, in this figure, which has the form of an orthogonal coordinate system, the x-axis corresponds to a pressure differential DP maintained at the limits of passive valve 106 , while the y-axis corresponds to an altitude at which valve 106 is located. The various situations—or operating points—are physically represented by triangles 402 , which correspond to the case in which turbojet 101 is operating at low speed, and for which ejector 102 is in the on state, or by circles 403 , which correspond to the case in which turbojet 101 is operating at high speed, and for which ejector 102 is in the blocking state.
[0010] As is shown in FIGS. 5A , 5 B and 5 C, a difficulty then arises in determining the activation threshold of one of the two configurations (ejector in on state or ejector in blocking state). In fact, if DP 0 is defined as a constant regardless of the altitude under consideration, it is observed that:
[0011] as shown in FIG. 5A , high-speed situations 501 are complied with for a pressure differential level DP lower than threshold DP 0 , valve 106 then being open, the ejector thus being activated in such manner that engine performance may be impaired;
[0012] as shown in FIG. 5B , either low-speed situations 502 are maintained for a pressure differential DP level higher than threshold DP 0 , in which case valve 106 is closed, thus also deactivating ejector 102 with the associated risk of not satisfying the minimum pressure differential specifications for the purpose of liquid-tightness, and possibly allowing oil leaks to occur.
[0013] Moreover, as shown in FIG. 5C , there are situations 503 at low speed and high altitude for which it is possible that the ejector with its check valve fully open may create excessive aspiration within the chambers, thus leading to an excessively sharp loss of pressure in the oil chambers, so that this pressure falls to a level below a minimum pressure that is essential to ensure the proper functioning of the oil recovery pumps associated with the chamber.
[0014] In view of the above, it is desirable to provide a valve on the ejector with an activation system that:
enables the ejector to be activated only at low speed operating points in order to guarantee the minimum pressure differential at the sealing limits of the chamber, and also to avoid the risk of oil leaks occurring; prevents air from being drawn from the high-pressure compressor at the high speed operating points in order to avoid impairing engine performance; and beneficially reduces the power of the ejector in low speed phases and at high altitude in order not to interfere with the operation of the oil recovery pumps.
[0018] It is clear that such a valve type is complex. A valve governed by the full authority digital engine control (FADEC) that satisfies these requirements exists, ensuring the proper function of the jet pump at the various operating points of the flight envelope of the LEAP-X®. However, this is a solution that requires a FADEC output and entails higher cost. Such a solution exceeds the definition limits of passive ejector valves because it relies on an electrical control.
SUMMARY
[0019] An aspect of the invention offers a solution to the problems described in the preceding by providing an apparatus or device for activating a passive ejector valve, which control device satisfies at least the requirements according to which the ejector is only activated at the low speed operating points and the ejector is stopped in order to prevent intake of air from the high-pressure compressor for all of the high-speed operating points in order to avoid impairing engine performance.
[0020] To this end, in an embodiment according to the invention the operation of the valve is rendered dependent on the altitude at which it is located. In an embodiment, the valve is still a passive valve with two positions—position 100% open and position 100% closed—the activation threshold of which depends on its altitude. In another embodiment, the valve opens gradually as a function of its altitude. In yet another embodiment, the valve's activation threshold depends on its altitude and the valve opens gradually as a function of its altitude once the activation threshold has been reached.
[0021] An aspect of the present invention therefore relates essentially to an apparatus for activating a passive ejector valve in order to improve the pressurisation of a chamber in an aircraft turbojet engine, the apparatus comprising a device constructed and arranged to trigger the opening and/or closing of the valve and/or the power of the valve depending on the altitude at which the valve is located. The power of the valve refers to the quantity of air that it allows to pass per unit of time.
[0022] The device constructed and arranged to trigger the opening and/or closing of the valve can be broadly termed a “trigger.”
[0023] An aspect of the present invention therefore relates essentially to an apparatus for activating a passive ejector valve in order to improve the pressurisation of a chamber in an aircraft turbojet engine, the apparatus comprising a means for triggering the opening and/or closing of the valve and/or the power of the valve depending on the altitude at which the valve is located.
[0024] Besides the main features, which were outlined in the previous paragraph, the apparatus according to an embodiment of the invention may include one or more additional characteristics from the following, either individually or in any technical possible combination:
the device constructed and arranged to trigger the opening and/or closing of the valve is constructed and arranged to toggle the valve between a fully open position and a fully closed position as a function of a triggering threshold determined by the altitude; accordingly, no intermediate position is possible for the valve; the device constructed and arranged to trigger the opening and/or closing of the valve comprises: a multiplier element that receives ambient air pressure and air drawn from the high-pressure compressor at its intake; a binary flap valve that receives the air supplied by the multiplier element and ambient pressure air at its intake, the binary flap valve being able to progress from an open position in which the air taken from the high-pressure compressor is sent through the valve to the ejector to create a Venturi effect, and a closed position in which the air is blocked by the valve; the air received by the multiplier element and the air sent through the valve have the same origin; the device constructed and arranged to trigger the opening and/or closing of the valve is constructed and arranged to cause the valve to progress from a fully open position to a fully closed position, the valve assuming intermediate, partially open positions as a function of altitude; the device constructed and arranged to trigger the opening and/or closing of the valve comprises a piston whose movement is controlled by the ambient pressure air, the piston revealing a passage having a profile that varies according to the ambient pressure of the air that controls the travel of said piston, which passage allows the pressurised air to pass through the valve; the air that controls the travel of the piston comes from a high-pressure compressor of the turbojet engine; the device constructed and arranged to trigger the opening and/or closing of the valve is constructed and arranged to cause the valve to progress from a fully open position to a fully closed position, said valve assuming intermediate, partially open positions as a function of altitude until a triggering threshold that depends on the altitude relative to a pressure differential exerted on the valve is reached.
[0034] An embodiment of the present invention also relates to an aircraft equipped with the apparatus or device according to various embodiments of the invention.
[0035] Embodiments of the invention and its various applications will be better understood after reading the following description and reviewing the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The figures are intended for purely exemplary purposes and not intended to limit the invention in any way.
[0037] In the drawing:
[0038] FIG. 1 , described in the preceding, is a diagrammatic representation of a part of a turbojet engine according to the prior art, equipped with an ejector having a passive valve;
[0039] FIG. 2 , also described in the preceding, is a diagrammatic representation of an ejector;
[0040] FIGS. 3A and 3B , also described in the preceding, are diagrammatic illustrations of various positions of an ejector valve according to the prior art;
[0041] FIG. 4 is a mapping of different situations to which the passive valve may be subjected;
[0042] FIGS. 5A to 5C show various representations of the mapping of FIG. 4 that illustrate the difficulty of defining a constant triggering threshold for the valve;
[0043] FIGS. 6A to 6C , show various representations of the mapping of FIG. 4 that illustrate different embodiments of an apparatus according to an embodiment of the invention;
[0044] FIGS. 7A and 7B , show various representations of a first example of the apparatus according to an embodiment of the invention;
[0045] FIGS. 8A and 8B , show various representations of a second example of the apparatus according to an embodiment of the invention.
DETAILED DESCRIPTION
[0046] Unless stated otherwise, the same element appearing in different figures will be identified by the same reference numeral.
[0047] In the various illustrations that follow, a pressure differential DP applied to valve 106 for the purpose of actuating it is defined for purely exemplary purposes according to the following relationship: DP=P 28 −Pamb; where P 28 is the pressure in the seventh stage of the high-pressure compressor and Pamb is ambient pressure.
[0048] FIG. 6A shows a mapping 401 that illustrates the use of a first exemplary embodiment of the apparatus according to an embodiment of the invention. In this example, it is suggested to implement a two-position passive activation system—valve 106 either fully closed or fully open—with an activation threshold 601 for ejector valve 106 that develops progressively with altitude, valve 106 being open when the operating point under consideration corresponds to a valve exposed to a pressure differential less than activation threshold 601 for a given altitude. The solution suggested thus enables the corresponding valve to be triggered as needed: valve open at low speed points and closed at high speed points.
[0049] FIG. 6B shows mapping 401 that illustrates the use of a second exemplary embodiment of the apparatus according to an embodiment of the invention. In this example, it is suggested to implement a passive activation system of a valve whose opening profile varies progressively according to the altitude, with a fixed activation threshold 608 for the valve. Thus, the valve's opening cross section varies progressively with the ambient pressure, which is a direct function of altitude, valve 106 being open when the pressure delta that actuates the valve is lower than activation threshold 608 . In this manner, when the valve is open, as the altitude increases so the ambient pressure falls and the passage cross section of the valve also becomes smaller. In the example shown, various plateaux may be observed: a first plateau 604 during which valve 106 is fully open; a second plateau 605 during which valve 106 is 75% open; a third plateau 606 during which valve 106 is 50% open; a third plateau ; a fourth plateau 607 during which valve 106 is 25% open.
[0050] The solution suggested in this example thus enables the creation of an ejector whose power is modulated when it is active, while thus avoiding the risk of lowering the pressure in the oil chambers to below the pressure specifications for the oil recovery pumps at the low speed and high altitude points.
[0051] Since activation threshold 608 is fixed to guarantee that a minimum pressure differential is maintained for all operating points at the sealing points of the chambers, there are a number of high speed operating points 603 for which the ejector does not need to be activated, but for which the ejector is activated anyway. However, with such a valve type, in which the power of the ejector is modulated by altitude, the impact in terms of engine performance of extracting air from the high-pressure compressor during high-speed phases is limited.
[0052] FIG. 6C shows the mapping 401 that illustrates the use of a third embodiment of the apparatus according to an embodiment of the invention.
[0053] FIGS. 7A and 7B show respectively an outline diagram and a functional diagram of the apparatus according to an embodiment of the invention. In these figures, a first, multiplier type element 701 , for example a bellows system 711 , receives at its intake ambient air Pamb and air at pressure P 28 that has been pressurised inside the high-pressure compressor to supply air at a pressure α*P 28 at the outlet thereof; pressure multiplication is thus effected by the presence of a variable section 718 which depends directly on Pamb, and thus consequently on the altitude. The air at pressure α*P 28 is then communicated to second, on/off type check valve 702 , (all or nothing), which receives air at ambient pressure at the intake thereof.
[0054] The on-off check valve controls the transmission of P 28 air to the ejector. To do this, the P 28 air is sent into a compartment of which one outlet 713 is blocked by an extremity 714 of check valve 702 ; check valve 702 also comprises a base 715 braced against spring 716 , the base being exposed on either side to air at ambient pressure Pamb which is sent to a second compartment 717 and to air that is pressurised to pressure α*P 28 . Thus, the check valve is controlled by the difference in pressure between Pamb and α*P 28 .
[0055] FIGS. 8A and 8B show respectively a first and second block diagram of the second exemplary apparatus according to an embodiment the invention. In this example, an opening section 802 of the valve is rendered dependent on ambient pressure Pamb. Consequently, one has created a passive valve with a variable section, the valve opening section changing progressively with the altitude by means of the movement of piston 801 to allow the air at pressure P 28 to pass: the as the altitude increases, so the ambient pressure falls, and the passage section in the valve also falls correspondingly until it is closed completely, as shown in FIG. 8-A . The air at pressure P 28 is injected into the apparatus through an aperture 804 , and can only escape via an outlet 805 as long as opening cross section 802 is not zero. The movement of piston 801 may be initiated for example by a bellows 803 attached permanently to piston 801 , subjected to ambient pressure, or it may be triggered by the use of aneroid cells.
[0056] The third example, shown in FIG. 6C , is also the object of a functional configuration that connects outlet 713 shown in FIG. 7-B to intake 804 shown in FIGS. 8A and 8B .
[0057] The descriptions above are intended to be illustrative, not limiting. Thus, it will be appreciated by one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.
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An apparatus for activating a valve of an ejector in order to adapt the pressurisation of a chamber in an aircraft turbojet engine comprising a device constructed and arranged to trigger the opening and/or closing of valve and/or the power of the valve as a function of the altitude at which the valve is located.
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TECHNICAL FIELD
[0001] The present invention relates to an aliphatic polyester resin composition, and particularly relates to a polyester resin composition intended to allow a biodegradable polyester resin, which is decomposed by the action of microorganisms, to be applied to various industrial materials, and a molded article comprising such a polyester resin composition.
BACKGROUND ART
[0002] In recent years, biodegradable plastics have been actively developed as materials that can solve problems caused by the heavy burden of plastic waste on the global environment, such as harmful effects on the ecosystem, generation of harmful gas during combustion, and global warming due to a large amount of heat generated by combustion.
[0003] Particularly, carbon dioxide generated by combustion of plant-derived biodegradable plastics was originally present in the air. Therefore, combustion of plant-derived biodegradable plastics does not increase the amount of carbon dioxide in the atmosphere. This is referred to as “carbon neutral”, and is regarded as important under The Kyoto Protocol that sets targets for reducing carbon dioxide emissions. Therefore, active use of plant-derived biodegradable plastics is desired.
[0004] Recently, from the viewpoint of biodegradability and carbon neutral, aliphatic polyester-based resins have received attention as plant-derived plastics. Particularly, polyhydroxyalkanoate (hereinafter, sometimes referred to as PHA)-based resins have received attention. Among PHA-based resins, poly(3-hydroxybutyrate) homopolymer resins (hereinafter, sometimes referred to as P3HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer resins (hereinafter, sometimes referred to as P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resins (hereinafter, sometimes referred to as P3HB3HH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer resins, polylactic acid, etc. have received attention.
[0005] However, it is known that the PHA-based resins are slow in crystallization. Therefore, the PHA-based resins require a long cooling time for solidification after heat-melting in molding processing, which causes problems such as poor molding processability and poor productivity.
[0006] Therefore, blending of a PHA-based resin with an inorganic material such as boron nitride, titanium oxide, talc, lamellar silicate, calcium carbonate, sodium chloride, or metal phosphate has heretofore been proposed to promote crystallization. However, the blending with an inorganic material has many adverse effects on a resulting molded article, such as reduction in tensile elongation and poor appearance, and is therefore poorly effective.
[0007] PTL 1 discloses that blending of a PHA-based resin with an amide bond-containing compound promotes the crystallization of the PHA-based resin. However, further improvement is desired to improve productivity.
CITATION LIST
Patent Documents
[0008] Patent Document 1: JP-T-2008-513578
SUMMARY OF INVENTION
Technical Problem
[0009] It is an object of the present invention to improve slow crystallization that is a drawback of biodegradable polyesters, especially polyhydroxyalkanoates, which are decomposed into water and carbon dioxide by the action of microorganisms, to provide a resin composition that has improved molding processability in molding processing such as injection molding or sheet molding and exhibits excellent productivity in molding or pellet production.
Solution to Problem
[0010] The present inventors have found that the crystallization of a polyhydroxyalkanoate slow in crystallization can be promoted by blending the polyhydroxyalkanoate with an amide bond-containing compound and pentaerythritol so that molding processability and productivity are improved, which has led to the completion of the present invention.
[0011] That is, the present invention is directed to an aliphatic polyester resin composition comprising a polyhydroxyalkanoate (A), an amide bond-containing compound (B), and pentaerythritol (C), wherein
[0012] the amide bond-containing compound (B) is any one of compounds represented by the following general formulas: R 1 —C(O)N(R 2 ) 2 , R 1 —C(O)NH—(R 3 )—NHC(O)—R 1 , R 1 —NHC(O)NH—(R 3 )—NHC(O)NH—R 1 , R 1 —NHC(O)—R 2 , R 1 —NHC(O)—(R 3 )—C(O)NH—R 1 , R 1 —C(O)NH—(R 3 )—C(O)NH—R 1 , R 1 —NHC(O)NH—(R 3 )—C(O)NH—R 1 , and R 1 —NHC(O)NH—(R 3 )—NHC(O)—R 1 , or a combination of two or more of the compounds, and in the formulas,
[0013] R 1 s are each independently a C 6 to C 30 alkyl,
[0014] R 2 s are each independently H or a C 1 to C 20 alkyl, and
[0015] R 3 s are each independently a C 2 to C 10 alkylene.
[0016] The amide bond-containing compound (B) is preferably one or more selected from lauramide, myristamide, stearamide, behenamide, and erucamide.
[0017] The amount of the pentaerythritol (C) is preferably 0.05 to 12 parts by weight with respect to 100 parts by weight of the polyhydroxyalkanoate (A).
[0018] The polyhydroxyalkanoate (A) preferably contains a repeating unit represented by the following general formula (1)
[0000] [—CHR—CH 2 —CO—O—] (1)
[0019] (wherein R is an alkyl group represented by C n H 2n+1 and n is an integer of 1 or more and 15 or less).
[0020] The polyhydroxyalkanoate (A) is preferably one or more selected from a poly(3-hydroxybutyrate) homopolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resin, and a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer resin.
[0021] The present invention is also directed to a polyester resin molded article obtained by molding the aliphatic polyester resin composition.
Advantageous Effects of Invention
[0022] The resin composition according to the present invention can improve slow crystallization of a polyhydroxyalkanoate to improve molding processability in molding processing, such as injection molding or sheet molding, and productivity in molding or pellet production.
DESCRIPTION OF EMBODIMENTS
[0023] Hereinbelow, the present invention will be described in more detail.
[0024] An aliphatic polyester resin composition according to the present invention contains a PHA (A), an amide bond-containing compound (B), and pentaerythritol (C).
[0025] [Polyhydroxyalkanoate (A)]
[0026] In the present invention, the PHA (A) is an aliphatic polyester resin containing a repeating unit represented by the following general formula: [—CHR—CH 2 —CO—O—].
[0027] The PHA (A) used in the present invention is preferably an aliphatic polyester containing a repeating unit represented by the following formula (1): [—CHR—CH 2 —CO—O—] (wherein R is an alkyl group represented by C n H 2n+1 and n is an integer of 1 or more and 15 or less).
[0028] Particularly, from the viewpoint of molding processability and the physical properties of a molded article, the PHA (A) preferably contains a 3-hydroxybutyrate unit, a 3-hydroxyvalerate unit, a 3-hydroxyhexanoate unit, or a 4-hydroxybutyrate unit.
[0029] Further, the PHA (A) is preferably a polymer resin comprising 80 mol % or more of 3-hydroxybutyrate, and is more preferably a polymer resin comprising 85 mol % or more of 3-hydroxybutyrate. The PHA (A) is preferably produced by a microorganism. Specific examples of the PHA (A) include a poly(3-hydroxybutyrate) homopolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxypropionate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyheptanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxynonanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxydecanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyundecanoate) copolymer resin, and a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer resin.
[0030] Particularly, from the viewpoint of molding processability and the physical properties of a molded article, a poly(3-hydroxybutyrate) homopolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) copolymer resin, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resin, and a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer resin are suitable for use as the PHA (A).
[0031] From the viewpoint of molding processability and the quality of a molded article, the content of 3-hydroxybutyrate (hereinafter, sometimes referred to as 3HB) to a comonomer copolymerized therewith, such as 3-hydroxyvalerate (hereinafter, sometimes referred to as 3HV), 3-hydroxyhexanoate (hereinafter, sometimes referred to as 3HH), or 4-hydroxybutyrate (hereinafter, sometimes referred to as 4HB), in the PHA (A), that is, the content of monomers in a copolymer resin as the PHA (A) is preferably 97/3 to 80/20 (mol %/mol %), more preferably 95/5 to 85/15 (mol %/mol %). If the comonomer content is less than 3 mol %, there is a case where a molding processing temperature and a pyrolysis temperature are close to each other, and therefore molding processing is difficult to perform. If the comonomer content exceeds 20 mol %, there is a case where the PHA(A) is slowly crystallized, and therefore productivity is poor.
[0032] Each monomer content in a copolymer resin as the PHA (A) can be measured by gas chromatography in the following manner. About 20 mg of the dry PHA is mixed with 2 mL of a sulfuric acid/methanol mixed liquid (15/85 (weight ratio)) and 2 mL of chloroform in a vessel, and the vessel is tightly sealed. Then, the mixture is heated at 100° C. for 140 minutes to obtain a methyl ester of PHA degradation product. After cooling, 1.5 g of sodium hydrogen carbonate is added thereto little by little for neutralization, and the resulting mixture is allowed to stand until generation of carbon dioxide gas is stopped. The mixture is well mixed with 4 mL of diisopropyl ether, and then the monomer unit composition of the PHA degradation product in a supernatant is analyzed by capillary gas chromatography to determine each monomer content in the copolymer resin.
[0033] The gas chromatography is performed using “GC-17A” manufactured by SHIMADZU CORPORATION as a gas chromatograph and “NEUTRA BOND-1” (column length: 25 m, column inner diameter: 0.25 mm, liquid film thickness: 0.4 μm) manufactured by GL Sciences Inc. as a capillary column. He gas is used as a carrier gas, a column inlet pressure is set to 100 kPa, and a sample is injected in an amount of 1 μL. As for temperature conditions, the temperature is increased from an initial temperature of 100° C. to 200° C. at a rate of 8° C./min, and is further increased from 200 to 290° C. at a rate of 30° C./min.
[0034] In the present invention, the weight-average molecular weight (hereinafter, sometimes referred to as Mw) of the PHA (A) is preferably 200000 to 2500000, more preferably 250000 to 2000000, even more preferably 300000 to 1000000. If the weight-average molecular weight is less than 200000, there is a case where, for example, mechanical properties are poor. If the weight-average molecular weight exceeds 2500000, there is a case where molding processing is difficult to perform.
[0035] The weight-average molecular weight can be measured using a gel permeation chromatograph (GPC) (“Shodex GPC-101” manufactured by Showa Denko K.K.), a polystyrene gel column (“Shodex K-804” manufactured by Showa Denko K.K.), and chloroform as a mobile phase, and can be determined as a molecular weight based on a polystyrene calibration curve. In this case, the calibration curve is prepared using polystyrene standards having weight-average molecular weights of 31400, 197000, 668000, and 1920000.
[0036] It is to be noted that the PHA is produced by a microorganism such as Alcaligenes eutrophus AC32 strain produced by introducing a PHA synthetic enzyme gene derived from Aeromonas caviae into Alcaligenes eutrophus (International Deposit under Budapest Treaty, International Depository Authority: International Patent Organism Depositary, National Institute of Advanced Science and Technology (6 Chuo, 1-1-1, Higashi, Tsukuba, Ibaraki, Japan), Date of Original Deposit: Aug. 12, 1996, transferred on Aug. 7, 1997, Deposit Number: FERM BP-6038 (transferred from original deposit FERM P-15786)) (J. Bacteriol., 179, 4821 (1997)).
[0037] [Amide Bond-Containing Compound (B)]
[0038] The amide bond-containing compound (B) used in the present invention is any one of compounds represented by the following general formulas:
[0000] R 1 —C(O)N(R 2 ) 2 , R 1 —C(O)NH—(R 3 )—NHC(O)—R 1 , R 1 —NHC(O)NH—(R 3 )—NHC(O)NH—R 1 , R 1 —NHC(O)—R 2 , R 1 —NHC(O)—(R 3 )—C(O)NH—R 1 , R 1 —C(O)NH—(R 3 )—C(O)NH—R 1 , R 1 —NHC(O)NH—(R 3 )—C(O)NH—R 1 , and R 1 —NHC(O)NH—(R 3 )—NHC(O)—R 1 . These compounds may be used singly or in combination of two or more of them.
[0039] R 1 s are each independently a C 6 to C 30 alkyl, preferably a C 12 to C 22 alkyl. R 2 s are each independently H or a C 1 to C 20 alkyl, preferably H or a C 1 to C 6 alkyl, more preferably H. R 3 s are each independently a C 2 to C 10 alkylene, preferably a C 2 to C 6 alkylene. Here, the alkyl group or alkylene group may be saturated or unsaturated.
[0040] Among them, from the viewpoint of affinity for the polyhydroxyalkanoate (A), a compound represented by R 1 —C(O)NH 2 is preferred. Specific examples of such a compound include lauramide, myristamide, stearamide, behenamide, and erucamide.
[0041] The amount of the amide bond-containing compound (B) used in the present invention is not particularly limited as long as the crystallization of the polyhydroxyalkanoate (A) can be promoted. However, in order to obtain the effect of the amide bond-containing compound (B) as a crystal nucleating agent, the lower limit of the amount of the amide bond-containing compound (B) contained is preferably 0.01 parts by weight, more preferably 0.05 parts by weight, even more preferably 0.1 parts by weight with respect to 100 parts by weight of the amount of the polyhydroxyalkanoate (A) contained. If the amount of the amide bond-containing compound (B) is too large, there is a case where the viscosity of the aliphatic polyester resin composition during melt processing is reduced, and therefore it is difficult to process the aliphatic polyester resin composition. Therefore, the upper limit of the amount of the amide bond-containing compound (B) contained is preferably 10 parts by weight, more preferably 7 parts by weight, even more preferably 5 parts by weight with respect to 100 parts by weight of the amount of the polyhydroxyalkanoate (A) contained.
[0042] [Pentaerythritol (C)]
[0043] The aliphatic polyester resin composition according to the present invention uses pentaerythritol (C) as a crystal nucleating agent for the polyhydroxyalkanoate (A).
[0044] The pentaerythritol (C) is a compound represented by the following formula (2).
[0000]
[0045] The pentaerythritol (C) is one of polyhydric alcohols and is an organic compound in a white crystal form with a melting point of 260.5° C. The pentaerythritol (C) is classified as a sugar alcohol, but is not derived from a natural product and can be synthesized by condensation of acetaldehyde and formaldehyde in a basic environment.
[0046] The pentaerythritol (C) used in the present invention is not particularly limited as long as it is usually commonly available, and may be a reagent or an industrial product. Examples of the reagent include, but are not limited to, those manufactured by Wako Pure Chemical Industries, Ltd., Sigma-Aldrich, Tokyo Chemical Industry Co., Ltd., and Merck Ltd. Examples of the industrial product include, but are not limited to, those manufactured by KOEI CHEMICAL CO., LTD. (trade name: Pentarit) and TOYO CHEMICALS CO., LTD.
[0047] Some of such commonly-available reagents and industrial products contain, as an impurity, an oligomer produced by dehydration condensation of the pentaerythritol (C), such as dipentaerythritol or tripentaerythritol. The oligomer does not have the effect of crystallizing the polyhydroxyalkanoate (A), but does not inhibit the crystallization effect of the pentaerythritol (C). Therefore, the oligomer may be contained.
[0048] The amount of the pentaerythritol (C) used in the present invention is not particularly limited as long as the crystallization of the polyhydroxyalkanoate (A) can be promoted. However, in order to obtain the effect of the pentaerythritol (C) as a crystal nucleating agent, the lower limit of the amount of the pentaerythritol (C) contained is preferably 0.05 parts by weight, more preferably 0.1 parts by weight, even more preferably 0.5 parts by weight with respect to 100 parts by weight of the amount of the polyhydroxyalkanoate (A) contained. If the amount of the pentaerythritol (C) is too large, there is a case where the viscosity of the aliphatic polyester resin composition during melt processing is reduced, and therefore it is difficult to process the aliphatic polyester resin composition. Therefore, the upper limit of the amount of the pentaerythritol (C) contained is preferably 12 parts by weight, more preferably 10 parts by weight, even more preferably 8 parts by weight with respect to 100 parts by weight of the amount of the polyhydroxyalkanoate (A) contained.
[0049] [Aliphatic Polyester Resin Composition]
[0050] The aliphatic polyester resin composition according to the present invention is superior to a polyhydroxyalkanoate itself, a resin composition comprising a polyhydroxyalkanoate and an amide bond-containing compound, or a resin composition comprising a polyhydroxyalkanoate and a sugar alcohol compound other than pentaerythritol in that crystallization of the resin composition stably progresses during processing under a wide range of processing conditions, and therefore has the following advantages.
[0051] In the case of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HB3HV) as an example of the polyhydroxyalkanoate, the progress of its crystallization induced by cooling after heat-melting is influenced by a resin temperature during melting. That is, the crystallization is less likely to progress when a resin temperature during melting is higher. For example, in the case of P3HB3HH, when a resin temperature during melting is in the range of the melting point of the resin to about 170° C., the crystallization of the resin during cooling is less likely to progress when the resin temperature during melting is higher. Further, when the resin temperature during melting is about 180° C. or higher, the crystallization of the resin during cooling tends to progress over several hours. Therefore, in order to successfully perform molding processing, the resin temperature during melting needs to be controlled to be in the range of about 170° C. to 180° C. However, in commonly-performed molding processing, the resin temperature during melting is not uniform, and therefore it is very difficult to control the resin temperature during melting to be in the above range.
[0052] The crystallization of the aliphatic polyester resin composition according to the present invention stably progresses even when a resin temperature during melting is in a wide range. That is, the crystallization of the resin composition quickly progresses with stability even when a resin temperature during melting is in the range of the melting point of the resin to about 190° C., and therefore the resin composition according to the present invention has excellent processing characteristics under a wide range of processing conditions. It is to be noted that from the viewpoint of thermal degradation, it is not preferred that melt processing is performed when the resin temperature during melting is 200° C. or higher.
[0053] Further, the progress of crystallization of the polyhydroxyalkanoate (A) depends also on a cooling temperature. For example, in the case of P3HB3HH, its crystallization tends to most progress when a cooling temperature after heat-melting is 50 to 70° C., and its crystallization is less likely to progress when the cooling temperature is lower than 50° C. or higher than 70° C. In commonly-performed molding processing, a mold temperature correlates to the cooling temperature, and therefore needs to be controlled to be in the above temperature range of 50° C. to 70° C. However, in order to uniformly control the mold temperature, the structure or shape of a mold needs to be tightly designed, which is very difficult.
[0054] The crystallization of the aliphatic polyester resin composition according to the present invention stably progresses even when the cooling temperature of the resin after melting is in a wide range. That is, the crystallization of the resin composition quickly progresses with stability even when a cooling temperature after heat-melting is in the range of 20° C. to 80° C., and therefore the resin composition according to the present invention has excellent processing characteristics under a wide range of processing conditions.
[0055] The aliphatic polyester resin composition according to the present invention has the above advantages that cannot be obtained by any conventional polyhydroxyalkanoate itself, resin composition comprising a polyhydroxyalkanoate and an amide bond-containing compound, or resin composition comprising a polyhydroxyalkanoate and a sugar alcohol compound other than the pentaerythritol, which makes it possible to set a resin temperature during melting or a cooling temperature, such as a mold temperature, over a wide range. Therefore, the aliphatic polyester resin composition has excellent processing characteristics.
[0056] The aliphatic polyester resin composition according to the present invention is quickly crystallized with stability, and therefore exhibits the following characteristics.
[0057] For example, in the case of P3HB3HH, its crystallization does not sufficiently progress during molding, and therefore gradually progresses even after molding so that spherulites grow. This tends to gradually embrittle a molded article due to a temporal change in mechanical properties. On the other hand, in the case of the aliphatic polyester resin composition according to the present invention, a plurality of microcrystals are formed just after molding, and therefore spherulites are less likely to grow after molding. This suppresses embrittlement of a molded article. Therefore, the aliphatic polyester resin composition is excellent in the quality stability of its product.
[0058] Further, there is a gap at a joint between cavities of a mold for injection molding (e.g., parting line portion, insertion portion, slide core sliding portion), and therefore “burr” formed by injecting a molten resin into the gap during injection molding is attached to a molded article. The polyhydroxyalkanoate is slowly crystallized and has flowability for a long period of time. Therefore, burr is easily formed, and post-processing of a molded article requires much effort. However, the aliphatic polyester resin composition according to the present invention is quickly crystallized, which makes it difficult to form burr. Therefore, effort required for post-processing of a molded article can be reduced, which is preferred from a practical point of view.
[0059] The aliphatic polyester resin composition according to the present invention can be easily produced by a known melt-kneading machine as long as the machine can heat the polyester resin composition to a temperature equal to or higher than the melting point of the polyhydroxyalkanoate (A) and can knead the polyester resin composition. For example, the polyhydroxyalkanoate (A), the amide bond-containing compound (B), the pentaerythritol (C), and if necessary, another component may be melt-kneaded by an extruder, a roll mill, a Banbury mixer, or the like to form pellets, and then the pellets may be subjected to molding. Alternatively, a previously-prepared masterbatch containing high concentrations of the amide bond-containing compound (B) and the pentaerythritol (C) may be blended with the polyhydroxyalkanoate (A) in a desired ratio, and the resulting mixture may be melt-kneaded and subjected to molding. The pentaerythritol (C), the polyhydroxyalkanoate (A), and the amide bond-containing compound (B) may be added to a kneading machine at the same time. Alternatively, the amide bond-containing compound (B) and the pentaerythritol (C) may be added after the polyhydroxyalkanoate (A) is melted.
[0060] The aliphatic polyester resin composition according to the present invention may comprise various additives as long as the effects of the present invention are not impaired. Examples of the additives include lubricants, crystal nucleating agents other than the pentaerythritol (C) and the amide bond-containing compound (B), plasticizers, hydrolysis inhibitors, antioxidants, releasing agents, ultraviolet absorbers, coloring agents such as dyes and pigments, and inorganic fillers. These additives may be used depending on the intended use, but preferably have biodegradability.
[0061] Other examples of the additives include inorganic fibers such as carbon fibers and organic fibers such as human hair and wool. Alternatively, natural fibers may be used, such as bamboo fibers, pulp fibers, kenaf fibers, analogous other plant alternatives, annual herbaceous plants of the genus Hibiscus , family Malvaceae, and annual herbaceous plants of the family Tiliaceae. From the viewpoint of carbon dioxide reduction, plant-derived natural fibers are preferred, and kenaf fibers are particularly preferred.
[0062] [Molded Article Comprising Aliphatic Polyester Resin Composition]
[0063] The following is an example of a method for producing a molded article comprising the aliphatic polyester resin composition according to the present invention.
[0064] First, the PHA (A), the amide bond-containing compound (B), the pentaerythritol (C), and if necessary, the above-described various additives are melt-kneaded using an extruder, a kneader, a Banbury mixer, rolls, or the like to prepare an aliphatic polyester resin composition. Then, the aliphatic polyester resin composition is extruded into a strand, and the strand is cut to obtain aliphatic polyester resin composition pellets having a particle shape such as a column shape, an elliptic column shape, a spherical shape, a cubic shape, or a rectangular parallelepiped shape.
[0065] In the above-described melt-kneading, the temperature at which the PHA(A) is melt-kneaded depends on the melting point, melt viscosity, etc. of the PHA (A) used, so that the temperature cannot generally be defined. However, the resin temperature of a melt-kneaded product at a die outlet is preferably 140 to 200° C., more preferably 150 to 195° C., even more preferably 160 to 190° C. If the resin temperature of a melt-kneaded product is less than 140° C., there is a case where kneading is insufficient. If the resin temperature of a melt-kneaded product exceeds 200° C., there is a case where the PHA (A) is thermally decomposed.
[0066] The pellets prepared by the above method are sufficiently dried at 40 to 80° C. to remove moisture. Then, the pellets can be mold-processed by a known mold processing method to obtain any molded article. Examples of the molding processing method include film molding, sheet molding, injection molding, blow molding, blow molding, fiber spinning, extrusion foaming, and bead foaming.
[0067] Examples of a method for producing a sheet molded article include T-die extrusion molding, calender molding, and roll molding. However, the sheet molding methods are not limited thereto. The temperature at which sheet molding is performed is preferably 140 to 190° C. Further, a sheet obtained from the aliphatic polyester resin composition according to the present invention can be subjected to heat molding, vacuum molding, press molding, or sheet blow molding.
[0068] Examples of a method for producing an injection-molded article include injection molding methods such as an injection molding method commonly used to mold a thermoplastic resin, a gas assist molding method, and an injection compression molding method. According to the intended use, any injection molding method other than the above methods may be also used, such as an in-mold molding method, a gas press molding method, a two-color molding method, a sandwich molding method, PUSH-PULL, or SCORIM. However, the injection molding methods are not limited thereto. The temperature at which injection molding is performed is preferably 140 to 190° C., and the temperature of a mold is preferably 20 to 80° C., more preferably 30 to 70° C.
[0069] The molded article according to the present invention is suitable for use in the fields of agriculture, fishery, forestry, gardening, medicine, sanitary items, food industry, clothing, non-clothing, packaging, automobiles, building materials, etc.
EXAMPLES
[0070] Hereinbelow, the present invention will be specifically described with reference to examples, but the technical scope of the present invention is not limited by these examples.
Polyhydroxyalkanoate as a raw material A1: Polyhydroxyalkanoate obtained in Production Example 1 was used.
Production Example 1
[0072] The culture production of PHA was performed using KNK-005 strain (see U.S. Pat. No. 7,384,766).
[0073] The composition of a seed medium was: 1 w/v % Meat-extract, 1 w/v % Bacto-Tryptone, 0.2 w/v % Yeast-extract, 0.9 w/v % Na 2 HPO 4 .12H 2 O, and 0.15 w/v % KH 2 PO 4 (pH 6.8).
[0074] The composition of a preculture medium was: 1.1 w/v % Na 2 HPO 4 .12H 2 O, 0.19 w/v % KH 2 PO 4 , 1.29 w/v % (NH 4 ) 2 SO 4 , 0.1 w/v % MgSO 4 .7H 2 O, and 0.5 v/v % trace metal salt solution (prepared by dissolving, in 0.1 N hydrochloric acid, 1.6 w/v % FeCl 3 .6H 2 O, 1 w/v % CaCl 2 .2H 2 O, 0.02 w/v % CoCl 2 .6H 2 O, 0.016 w/v % CuSO 4 .5H 2 O, and 0.012 w/v % NiCl 2 .6H 2 O). Palm oil was added at a time as a carbon source at a concentration of 10 g/L.
[0075] The composition of a PHA production medium was: 0.385 w/v % Na 2 HPO 4 .12H 2 O, 0.067 w/v % KH 2 PO 4 , 0.291 w/v % (NH 4 ) 2 SO 4 , 0.1 w/v % MgSO 4 .7H 2 O, 0.5 v/v % trace metal salt solution (prepared by dissolving, in 0.1 N hydrochloric acid, 1.6 w/v % FeCl 3 .6H 2 O, 1 w/v % CaCl 2 .2H 2 O, 0.02 w/v % CoCl 2 .6H 2 O, 0.016 w/v % CuSO 4 .5H 2 O, and 0.012 w/v % NiCl 2 .6H 2 O), and 0.05 w/v % BIOSPUREX 200K (defoaming agent: manufactured by Cognis Japan Ltd.).
[0076] First, a glycerol stock (50 μL) of KNK-005 strain was inoculated into the seed medium (10 mL) and seed-cultured for 24 hours. Then, the resulting seed culture was inoculated at 1.0 v/v % into a 3-liter jar fermenter (MDL-300 manufactured by B. E. MARUBISHI Co., Ltd.) containing 1.8 L of the preculture medium. Preculture was performed for 28 hours under operation conditions where a culture temperature was 33° C., a stirring speed was 500 rpm, and a ventilation volume was 1.8 L/min while pH was controlled to be in the range of 6.7 to 6.8. The pH control was performed using a 14% aqueous ammonium hydroxide solution.
[0077] Then, the resulting preculture was inoculated at 1.0 v/v % into a 10-liter jar fermenter (MDS-1000 manufactured by B. E. MARUBISHI Co., Ltd.) containing 6 L of the production medium. Culture was performed under operation conditions where a culture temperature was 28° C., a stirring speed was 400 rpm, and a ventilation volume was 6.0 L/min while pH was controlled to be in the range of 6.7 to 6.8. The pH control was performed using a 14% aqueous ammonium hydroxide solution. Palm oil was used as a carbon source. The culture was performed for 64 hours. After the completion of the culture, cells were collected by centrifugal separation, washed with methanol, and lyophilized to measure the weight of the dried cells.
[0078] One-hundred milliliters of chloroform was added to 1 g of the obtained dried cells, and the resulting mixture was stirred at room temperature all day and night to extract PHA from the cells. The mixture was filtered to remove cell debris, and the resulting filtrate was concentrated by an evaporator until its total volume became 30 mL. Then, 90 mL of hexane was gradually added to the filtrate, and the resulting mixture was allowed to stand for 1 hour while being gently stirred. The mixture was filtered to separate the deposited PHA, and the PHA was vacuum-dried at 50° C. for 3 hours. The 3HH content of the obtained PHA was measured by gas chromatography in the following manner. Twenty milligrams of the dried PHA was mixed with 2 mL of a sulfuric acid-methanol mixed liquid (15:85) and 2 mL of chloroform in a vessel, and the vessel was tightly sealed. Then, the resulting mixture was heated at 100° C. for 140 minutes to obtain a methyl ester of PHA degradation product. After cooling, 1.5 g of sodium hydrogen carbonate was added thereto little by little for neutralization, and the resulting mixture was allowed to stand until generation of carbon dioxide gas was stopped. The mixture was well mixed with 4 mL of diisopropyl ether and then centrifuged. Then, the monomer unit composition of the polyester degradation product in a supernatant was analyzed by capillary gas chromatography. The gas chromatography was performed using GC-17A manufactured by SHIMADZU CORPORATION as a gas chromatograph and NEUTRA BOND-1 (column length: 25 m, column inner diameter: 0.25 mm, liquid film thickness: 0.4 μm) manufactured by GL Sciences Inc. as a capillary column. He gas was used as a carrier gas, a column inlet pressure was set to 100 kPa, and a sample was injected in an amount of 1 μL. As for temperature conditions, the temperature was increased from an initial temperature of 100 to 200° C. at a rate of 8° C./min, and was further increased from 200 to 290° C. at a rate of 30° C./min. As a result of the analysis performed under the above conditions, the PHA was found to be poly(3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH) represented by the chemical formula (1). The 3-hydroxyhexanoate (3HH) content was 5.6 mol % (3HB content: 94.4 mol %).
[0079] After the completion of the culture, PHBH was obtained from the culture by the method described in WO 2010/067543. The PHBH had a weight-average molecular weight Mw of 600000 as measured by GPC.
Polyhydroxyalkanoate as raw material A2: Polyhydroxyalkanoate obtained in Production Example 2 was used.
Production Example 2
[0081] A polyhydroxyalkanoate as a raw material A2, PHBH, was obtained in the same manner as in Production Example 1 except that KNK-631 strain (see WO 2009/145164) was used instead of KNK-005 strain. The PHBH had a weight-average molecular weight Mw of 620000 and a 3HH content of 7.8 mol % (3HB content: 92.2 mol %).
Polyhydroxyalkanoate as raw material A3: Polyhydroxyalkanoate obtained in Production Example 3 was used.
Production Example 3
[0083] A polyhydroxyalkanoate as a raw material A3, PHBH, was obtained in the same manner as in Production Example 1 except that KNK-631 strain was used and palm kernel oil was used as a carbon source. The PHBH had a weight-average molecular weight Mw of 650000 and a 3HH content of 11.4 mol % (3HB content: 88.6 mol %).
Polyhydroxyalkanoate as raw material A4: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (3-hydroxyvalerate (3HV) content: 5 mol %, 3HB content: 95 mol %) manufactured by Sigma-Aldrich was used. Amide bond-containing compound: The following commercially-available product was used. Raw material B1: BNT22H (behenamide) manufactured by NIPPON FINE CHEMICAL CO., LTD. Raw material B2: NEUTRON-2 (stearamide) manufactured by NIPPON FINE CHEMICAL CO., LTD.
Examples 1 to 7
Production of Aliphatic Polyester Resin Composition
[0088] The polyhydroxyalkanoate as a raw material A1, the amide bond-containing compound as a raw material B1 or B2, and pentaerythritol (manufactured by Wako Pure Chemical Industries, Ltd.) were blended in a blending ratio shown in Table 1 (blending ratios shown in the following tables are expressed in part(s) by weight) and melt-kneaded using a co-rotating intermeshing twin screw extruder (TEX30 manufactured by The Japan Steel Works, LTD.) at a preset temperature of 120 to 140° C. and a screw rotation speed of 100 rpm to obtain an aliphatic polyester resin composition. The aliphatic polyester resin composition was extruded through a die into a strand, and the strand was cut to obtain pellets. At this time, a resin temperature at a die outlet varied depending on the amount of the amide bond-containing compound blended or the amount of the pentaerythritol blended, but was in the range of 165 to 190° C.
[0089] (Release Time of Injection-Molded Article)
[0090] The obtained pellets as a raw material were molded into plate-shaped specimens of 150 mm×150 mm×2 mm thick using an injection molding machine (FN1000 manufactured by NISSEI PLASTIC INDUSTRIAL CO., LTD.) under conditions where the cylinder preset temperature of the molding machine was 130 to 160° C. and the preset temperature of a mold was 50° C. A resin temperature at time of injection or a mold temperature was measured by bringing a type K thermocouple into direct contact with an injected molten resin or the surface of the mold, respectively.
[0091] The release time was defined as the time required for a molten resin injected into the mold to cure so that a resulting specimen could be released from the mold without distortion when the mold was opened and the specimen was ejected by an ejector pin. A shorter release time means that crystallization is faster and molding processability is better.
Comparative Examples 1 to 4
[0092] Pellets of an aliphatic polyester resin composition were prepared in the same manner as in Examples 1 to 7 except that the blending ratio was changed as shown in Table 1. Then, the release time was measured during injection molding. The results are shown in Table 1.
[0000]
TABLE 1
Example
Comparative Example
1
2
3
4
5
6
7
1
2
3
4
Raw
Polyhydroxyalkanoate
Raw material A1
100
100
materials
Amide bond-containing
Raw material B1
1
1
1
3
3
0
1
3
compound
Amide bond-containing
Raw material B2
3
3
3
compound
Pentaerythritol
—
1
5
10
1
5
1
5
0
0
0
0
Injection
Resin temperature at
° C.
181
181
180
179
178
181
181
182
182
180
182
molding
time of injection
Mold temperature
° C.
51
51
52
52
52
53
53
52
52
52
53
Release time
sec.
27
20
16
25
17
28
21
57
50
48
56
[0093] When a molten resin is injected into the mold of 150 mm×150 mm×2 mm thick, a considerable shear force is applied to the resin at time of injection so that shear heat is generated. As a result, an actual resin temperature is much higher than the preset temperature. As shown in Table 1, when the resin temperature was as high as about 180° C. as in the comparative examples, the release time was as long as about 50 seconds or more. On the other hand, as shown in Table 1, when the pentaerythritol was used as in the examples, the release time was shorter in spite of the fact that the resin temperature was as high as that in the comparative examples due to the generation of shear heat. As can be seen from the above, the use of the pentaerythritol makes crystallization faster and improves molding processability.
Examples 8 to 14
Production of Aliphatic Polyester Resin Composition
[0094] Pellets of an aliphatic polyester resin composition were produced by blending raw materials in a ratio shown in Table 2 using a co-rotating intermeshing twin screw extruder (TEX30 manufactured by The Japan Steel Works, Ltd.) to evaluate pellet productivity.
[0095] (Pellet Productivity)
[0096] Pellet productivity was evaluated in the following manner. The preset temperature of the extruder was 120 to 140° C., and a screw rotation speed was gradually increased from 100 rpm to increase a discharge rate. A molten resin strand extruded through a die of the extruder is passed through a 1.5 m-long hot water bath filled with water set at 60° C. for crystallization and solidification, and is then cut by a pelletizer to obtain pellets. In order to increase a resin discharge rate to enhance pellet productivity, the linear speed of the strand needs to be increased by increasing the screw rotation speed of the extruder. When the screw rotation speed is increased, a resin temperature is increased by generation of shear heat. Further, the retention time of the strand in the hot water bath is shortened as the linear speed of the strand is increased. When the resin temperature is increased, the resin is less likely to be crystallized. Further, when the retention time of the strand in the hot water bath at 60° C. is shortened, the resin is not completely crystallized and remains soft. That is, when the resin temperature is increased and the retention time of the strand in the hot water bath is shortened, the strand cannot be cut by the pelletizer. Therefore, the maximum linear speed of the strand at which the strand could be cut into pellets was defined as a measure for evaluating pellet productivity. A higher liner speed means better pellet productivity. It is to be noted that the resin temperature was measured by bringing a type K thermocouple into direct contact with the molten resin extruded through the die of the extruder. The results are shown in Table 2.
Comparative Examples 5 to 9
[0097] The pellet productivity of an aliphatic polyester resin composition was evaluated in the same manner as in Examples 8 to 14. The results are shown in Table 2.
[0000]
TABLE 2
Example
Comparative Example
8
9
10
11
12
13
14
5
6
7
8
9
Raw
Polyhydroxyalkanoate
Raw material A1
100
100
100
100
100
materials
Polyhydroxyalkanoate
Raw material A2
100
100
Polyhydroxyalkanoate
Raw material A3
100
100
Polyhydroxyalkanoate
Raw material A4
100
100
100
Amide bond-containing
Raw material B1
1
1
3
1
3
1
1
1
3
1
3
1
compound
Pentaerythritol
—
1
5
1
5
10
1
5
—
—
—
—
—
Pellet
Resin temperature
° C.
176
190
175
177
165
177
192
170
171
168
168
175
production
Maximum linear speed
m/min
22
36
27
23
18
23
37
10
13
8
5
14
of strand
[0098] As can be seen from Table 2, the use of the pentaerythritol makes it possible to increase the linear speed of a strand and improve pellet productivity.
Examples 15 to 18
Production of Polyester Resin Composition
[0099] An aliphatic polyester resin composition was obtained by melt-kneading raw materials using a co-rotating intermeshing twin screw extruder (TEX30 manufactured by The Japan Steel Works, Ltd.) at a preset temperature of 120 to 140° C. and a screw rotation speed of 100 rpm. The aliphatic polyester resin composition was extruded through a die into a strand, and the strand was cut to obtain pellets.
[0100] (Sheet Productivity in T-Die Molding)
[0101] Sheet productivity was evaluated in the following manner. The obtained pellets as a raw material were molded into a 100 mm-wide sheet using a T-die sheet molding machine (Labo Plastomill manufactured by Toyo Seiki Seisaku-sho, Ltd.) under conditions where a die lip thickness was 250 μm, a die lip width was 150 mm, a cylinder preset temperature was 120 to 140° C., a die preset temperature was 150 to 160° C., and a cooling roll preset temperature was 60° C. A molten resin extruded through a T-die as a sheet is crystallized by contact with a cooling roll, and is therefore molded into a 100 μm-thick sheet. When the resin is sufficiently crystallized, the molded sheet is released from the cooling roll and rolled up. However, when the linear speed of the sheet is increased, the time of contact between the sheet and the cooling roll is shortened. As a result, the resin is not crystallized and is therefore not sufficiently solidified, which makes it impossible to release the sheet from the roll. Therefore, the maximum linear speed of the sheet at which the sheet could be released from the cooling roll was defined as a measure for evaluating sheet productivity. A higher liner speed means better sheet productivity. It is to be noted that the temperature of the molten resin extruded through the T-die was measured by direct contact with a type K thermocouple and defined as a resin temperature.
Comparative Examples 10 to 12
[0102] The sheet productivity of an aliphatic polyester resin composition was evaluated in the same manner as in Examples 15 to 18. The results are shown in Table 3.
[0000]
TABLE 3
Example
Comparative Example
15
16
17
18
10
11
12
Raw
Polyhydroxyalkanoate
Raw material A1
100
100
100
100
100
materials
Polyhydroxyalkanoate
Raw material A3
100
100
Amide bond-containing
Raw material B1
1
1
3
3
1
3
3
compound
Pentaerythritol
—
1
5
1
10
—
—
—
T-die
Resin temperature
° C.
165
164
164
162
165
164
162
molding
Maximum linear speed
m/min
14
23
16
7
4
5
2
of sheet
[0103] As can be seen from Table 3, the use of the pentaerythritol makes it possible to increase the linear speed of a sheet and improve sheet productivity.
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The present invention provides a resin composition that improves slow crystallization, which is a drawback of polyhydroxyalkanoates, and is excellent in molding processability and productivity. The resin composition is an aliphatic polyester resin composition comprising a polyhydroxyalkanoate (A), an amide bond-containing compound (B), and pentaerythritol (C), wherein the amide bond-containing compound (B) is represented by any one of the following general formulas: R 1 —C(O)N(R 2 ) 2 , R 1 —C(O)NH—(R 3 )—NHC(O)—R 1 , R 1 —NHC(O)NH—(R 3 )—NHC(O)NH—R 1 , R 1 —NHC(O)—R 2 , R 1 —NHC(O)—(R 3 )—C(O)NH—R 1 , R 1 —C(O)NH—(R 3 )—C(O)NH—R 1 , R 1 —NHC(O)NH—(R 3 )—C(O)NH—R 1 , and R 1 —NHC(O)NH—(R 3 )—NHC(O)—R 1 .
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TECHNICAL FIELD
[0001] The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting and receiving feedback information for device-to-device (D2D) communication in a wireless communication system supporting D2D communication.
BACKGROUND ART
[0002] Wireless communication systems are widely developed to provide a various kinds of communication services such as audio or data service. In general, a wireless communication system is a multiple access system capable of supporting communications with multiple users by sharing available system resources (bandwidths, transmission power, etc.). Examples of the multiple access system include code division multiple access (CDMA) system, frequency division multiple access (FDMA) system, time division multiple access (TDMA) system, orthogonal frequency division multiple access (OFDMA) system, single carrier frequency division multiple access (SC-FDMA) system, multi-carrier frequency division multiple access (MC-FDMA) system, etc. In a wireless communication system, a user equipment (UE) can receive information from a base station (BS) in downlink (DL) and transmit information to the BS in uplink (UL). The information transmitted or received by the UE includes data and various control information and various physical channels are present according to the type and usage of the information transmitted or received by the UE.
DISCLOSURE
Technical Problem
[0003] An object of the present invention devised to solve the problem lies in a method and apparatus for efficiently transmitting and receiving a control signal in a wireless communication system for supporting device-to-device (D2D) communication.
[0004] Another object of the present invention devised to solve the problem lies in a method and apparatus for providing feedback information to a base station (BS) so as to efficiently control D2D communication by the BS in a wireless communication system.
[0005] Another object of the present invention devised to solve the problem lies in a method and apparatus for providing feedback information to D2D communication to a BS even if one user equipment (UE) that performs D2D communication is outside coverage of the BS in a wireless communication system.
[0006] 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.
Technical Solution
[0007] In an aspect of the present invention, provided herein is a method for transmitting and receiving a control signal by a first user equipment (UE) in a wireless communication system supporting a device-to-device (D2D) communication, the method comprising receiving a signal for triggering a D2D communication between the first UE and a second UE from a base station (BS); transmitting data to the second UE; receiving an acknowledgement (ACK)/negative ACK (NACK) signal for the data from the second UE; and transmitting, to the BS, an ACK/NACK delivery signal for transmitting the ACK/NACK signal to the BS.
[0008] Preferably, the ACK/NACK delivery signal may indicate ACK when the ACK/NACK signal indicates ACK, and the ACK/NACK delivery signal may indicate NACK when the ACK/NACK signal indicates NACK or discontinuous transmission (DTX).
[0009] Preferably, the ACK/NACK delivery signal may indicate ACK when the ACK/NACK signal indicates ACK, the ACK/NACK delivery signal may indicate NACK when the ACK/NACK signal indicates NACK, and the ACK/NACK delivery signal may indicate DTX when the ACK/NACK signal indicates DTX.
[0010] Preferably, the ACK/NACK delivery signal may be transmitted via physical uplink control channel (PUCCH) format 1a/1b.
[0011] Preferably, the method further comprises transmitting, to the second UE, scheduling information for scheduling data transmission to the second UE, wherein the scheduling information may comprise resource allocation information, information about a modulation and coding scheme, and/or information about a transport block size, for data transmission to the second UE.
[0012] Preferably, the method further comprises receiving control information for the D2D communication between the first UE and the second UE from the BS, wherein the control information for the D2D communication may comprise information about a specific subframe in which data transmission to the second UE is permitted, and the data transmission to the second UE is performed in the specific subframe.
[0013] Preferably, information about resource and time for transmitting the ACK/NACK delivery signal to the BS may be received via higher layer signaling or received via the signal for triggering the D2D communication.
[0014] Preferably, the second UE may be outside a coverage of the BS.
[0015] In another aspect of the present invention, provided herein is a first user equipment (UE) for transmitting and receiving a control signal in a wireless communication system for supporting a device-to-device (D2D) communication, the first UE comprising: a radio frequency (RF) unit; and a processor, wherein the processor is configured to receive a signal for triggering a D2D communication between the first UE and a second UE from a base station (BS) through the RF unit, to transmit data to the second UE, to receive an acknowledgement (ACK)/negative ACK (NACK) signal for the data from the second UE, and to transmit, to the BS, an ACK/NACK delivery signal for transmitting the ACK/NACK signal to the BS.
[0016] Preferably, the ACK/NACK delivery signal may indicate ACK when the ACK/NACK signal indicates ACK, and the ACK/NACK delivery signal may indicate NACK when the ACK/NACK signal indicates NACK or discontinuous transmission (DTX).
[0017] Preferably, the ACK/NACK delivery signal may indicate ACK when the ACK/NACK signal indicates ACK, the ACK/NACK delivery signal may indicate NACK when the ACK/NACK signal indicates NACK, and the ACK/NACK delivery signal may indicate DTX when the ACK/NACK signal indicates DTX.
[0018] Preferably, the ACK/NACK delivery signal may be transmitted via physical uplink control channel (PUCCH) format 1a/1b.
[0019] Preferably, the processor is further configured to transmit, to the second UE, scheduling information for scheduling data transmission to the second UE from the first UE, and the scheduling information may comprise resource allocation information, information about a modulation and coding scheme, and/or information about a size of a transport block, for data transmission to the second UE from the first UE.
[0020] Preferably, the processor is further configured to receive control information for the D2D communication between the first UE and the second UE from the BS, and the control information for the D2D communication may comprise information about a specific subframe in which data transmission to the second UE from the first UE is permitted, and the data transmission to the second UE from the first UE is performed in the specific subframe.
[0021] Preferably, information about resource and time for transmitting the ACK/NACK delivery signal to the BS may be received via higher layer signaling or received via the signal for triggering the D2D communication.
[0022] Preferably, the second UE may be outside a coverage of the BS.
Advantageous Effects
[0023] According to the present invention, a control signal may be efficiently transmitted and received in a wireless communication system for supporting device-to-device (D2D) communication.
[0024] According to the present invention, feedback information may be provided to a base station (BS) so as to efficiently control D2D communication by the BS in a wireless communication system.
[0025] In addition, according to the present invention, feedback information to D2D communication may be provided to a BS even if one user equipment (UE) that performs D2D communication is outside coverage of the BS in a wireless communication system.
[0026] It will be appreciated by persons skilled in the art that that the effects that could be achieved with the present invention are not limited to what has been particularly described hereinabove and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0027] The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.
[0028] FIG. 1 illustrates physical channels and a general method for transmitting signals on the physical channels in the LTE(-A) system.
[0029] FIG. 2 illustrates a structure of a radio frame used in an LTE(-A) system.
[0030] FIG. 3 illustrates a resource grid of one DL slot used in an LTE(-A) system.
[0031] FIG. 4 illustrates a downlink subframe structure used in the LTE(-A) system.
[0032] FIG. 5 illustrates a control channel allocated to a downlink subframe.
[0033] FIG. 6 illustrates a structure of a UL subframe in the LTE(-A) system.
[0034] FIG. 7 illustrates an example of PHICH/UL grant (UG)-PUSCH timing.
[0035] FIG. 8 illustrates an example of PUSCH-PHICH/UL grant timing.
[0036] FIG. 9 illustrates an example in which a DL physical channel is allocated in a subframe.
[0037] FIG. 10 illustrates an example of a D2D data scheduling/transmitting procedure.
[0038] FIG. 11 illustrates an example of a D2D data scheduling/transmitting procedure.
[0039] FIG. 12 illustrates an example of a D2D feedback procedure according to the present invention.
[0040] FIG. 13 illustrates an example of a D2D feedback procedure according to the present invention.
[0041] FIG. 14 is a diagram illustrating a BS 110 and a UE 120 to which the present invention is applicable.
DETAILED DESCRIPTION OF THE INVENTION
[0042] The following embodiments of the present invention can be applied to a variety of wireless access technologies, for example, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and the like. CDMA may be embodied through wireless (or radio) technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be embodied through wireless (or radio) technology such as global system for mobile communication (GSM)/general packet radio service (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA may be embodied through wireless (or radio) technology such as institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and evolved UTRA (E-UTRA). UTRA is a part of universal mobile telecommunications system (UMTS). 3 rd generation partnership project (3GPP) long term evolution (LTE) is a part of E-UMTS (Evolved UMTS), which uses E-UTRA. LTE-Advanced (LTE-A) is an evolved version of 3GPP LTE. Throughout this specification, the LTE system may be referred to as a system according to 3 rd generation partnership project (3GPP) technical specification (TS) 36 8 (Release 8). In addition, in this specification, the LTE-A system may be referred to as a system according to 3GPP TS 36 series Release 9 and 10. The LTE(-A) system may be called to include the LTE system and the LTE-A system. For clarity, the following description focuses on 3GPP LTE(-A) system. However, technical features of the present invention are not limited thereto.
[0043] In a mobile communication system, a UE may receive information from a BS in downlink and transmit information in uplink. The information transmitted or received by the UE may be data and various control information. In addition, there are various physical channels according to the type or use of the information transmitted or received by the UE.
[0044] FIG. 1 illustrates physical channels and a general method for transmitting signals on the physical channels in the LTE(-A) system.
[0045] When a UE is powered on or enters a new cell, the UE performs initial cell search in step S 101 . The initial cell search involves acquisition of synchronization to an eNB. To this end, the UE synchronizes its timing to the eNB and acquires information such as a cell identifier (ID) by receiving a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from the eNB. Then the UE may acquire broadcast information in the cell by receiving a physical broadcast channel (PBCH) from the eNB. During the initial cell search, the UE may monitor a DL channel state by receiving a downlink reference signal (DL RS).
[0046] After the initial cell search, the UE may acquire more detailed system information by receiving a physical downlink control channel (PDCCH) and receiving a physical downlink shared channel (PDSCH) based on information of the PDCCH in step S 102 .
[0047] To complete access to the eNB, the UE may perform a random access procedure such as steps S 103 to S 106 with the eNB. To this end, the UE may transmit a preamble on a physical random access channel (PRACH) (S 103 ) and may receive a response message to the preamble on a PDCCH and a PDSCH associated with the PDCCH (S 104 ). In the case of a contention-based random access, the UE may additionally perform a contention resolution procedure including transmission of an additional PRACH (S 105 ) and reception of a PDCCH signal and a PDSCH signal corresponding to the PDCCH signal (S 106 ).
[0048] After the above procedure, the UE may receive a PDCCH and/or a PDSCH from the eNB (S 107 ) and transmit a physical uplink shared channel (PUSCH) and/or a physical uplink control channel (PUCCH) to the eNB (S 108 ), in a general UL/DL signal transmission procedure. Information that the UE transmits to the eNB is called Uplink Control Information (UCI). The UCI includes hybrid automatic repeat and request acknowledgement/negative acknowledgement (HARQ-ACK/NACK), scheduling request (SR), channel state information (CSI), etc. The CSI includes channel quality indicator (CQI), precoding matrix indicator (PMI), rank indication (RI), etc. UCI is generally transmitted on a PUCCH periodically. However, if control information and traffic data should be transmitted simultaneously, they may be transmitted on a PUSCH. In addition, the UCI may be transmitted aperiodically on the PUSCH, upon receipt of a request/command from a network.
[0049] FIG. 2 illustrates a structure of a radio frame used in an LTE(-A) system. In a cellular OFDM radio packet communication system, uplink/downlink data packet transmission is performed in subframe units and one subframe is defined as a predetermined duration including a plurality of OFDM symbols. The LTE(-A) standard supports a type-1 radio frame structure applicable to frequency division duplex (FDD) and a type-2 radio frame structure applicable to time division duplex (TDD).
[0050] FIG. 2( a ) shows the structure of the type-1 radio frame. A downlink radio frame includes 10 subframes and one subframe includes two slots in a time domain. A time required to transmit one subframe is referred to as a transmission time interval (TTI). For example, one subframe has a length of 1 ms and one slot has a length of 0.5 ms. One slot includes a plurality of OFDM symbols in a time domain and includes a plurality of resource blocks (RBs) in a frequency domain. In the LTE(-A) system, since OFDMA is used in downlink, an OFDM symbol indicates one symbol period. The OFDM symbol may be referred to as an SC-FDMA symbol or symbol period. A RB as a resource assignment unit may include a plurality of consecutive subcarriers in one slot.
[0051] The number of OFDM symbols included in one slot may be changed according to the configuration of a cyclic prefix (CP). The CP includes an extended CP and a normal CP. For example, if OFDM symbols are configured by the normal CP, the number of OFDM symbols included in one slot may be 7. If OFDM symbols are configured by the extended CP, since the length of one OFDM symbol is increased, the number of OFDM symbols included in one slot is less than the number of OFDM symbols in case of the normal CP. In case of the extended CP, for example, the number of OFDM symbols included in one slot may be 6. In the case where a channel state is unstable, such as the case where a UE moves at a high speed, the extended CP may be used in order to further reduce inter-symbol interference.
[0052] In case of using the normal CP, since one slot includes seven OFDM symbols, one subframe includes 14 OFDM symbols. At this time, a maximum of first two or three OFDM symbols of each subframe may be assigned to a physical downlink control channel (PDCCH) and the remaining OFDM symbols may be assigned to a physical downlink shared channel (PDSCH).
[0053] FIG. 2( b ) shows the structure of the type-2 radio frame. The type-2 radio frame includes two half frames and each half frame includes five subframes, a downlink pilot time slot (DwPTS), a guard period (GP) and an uplink pilot time slot (UpPTS). One subframe includes two slots. For example, a downlink slot (e.g., DwPTS) is used for initial cell search, synchronization or channel estimation of a UE. For example, an uplink slot (e.g., UpPTS) is used for channel estimation of a BS and uplink transmission synchronization of a UE. For example, the uplink slot (e.g., UpPTS) may be used to transmit a sounding reference signal (SRS) for channel estimation in an eNB and to transmit a physical random access channel (PRACH) that carriers a random access preamble for uplink transmission synchronization. The GP is used to eliminate interference generated in uplink due to multi-path delay of a downlink signal between uplink and downlink. Table 1 below shows an uplink (UL)-downlink (DL) configuration in subframes in a radio frame in a TDD mode.
[0000]
TABLE 1
Downlink-
to-Uplink
Uplink-
Switch-
downlink
point
Subframe number
configuration
periodicity
0
1
2
3
4
5
6
7
8
9
0
5 ms
D
S
U
U
U
D
S
U
U
U
1
5 ms
D
S
U
U
D
D
S
U
U
D
2
5 ms
D
S
U
D
D
D
S
U
D
D
3
10 ms
D
S
U
U
U
D
D
D
D
D
4
10 ms
D
S
U
U
D
D
D
D
D
D
5
10 ms
D
S
U
D
D
D
D
D
D
D
6
5 ms
D
S
U
U
U
D
S
U
U
D
[0054] In Table 1 above, D represents a DL subframe, U represents a UL subframe, and S represents a special subframe. The special subframe includes a downlink pilot timeslot (DwPTS), a guard period (GP), and an uplink pilot timeslot (UpPTS). Table 2 below shows a special subframe configuration.
[0000]
TABLE 2
Normal cyclic prefix in downlink
Extended cyclic prefix in downlink
UpPTS
UpPTS
Special
Normal
Extended
Normal
Extended
subframe
cyclic prefix
cyclic prefix
cyclic prefix
cyclic prefix
configuration
DwPTS
in uplink
in uplink
DwPTS
in uplink
in uplink
0
6592 · T S
2192 · T S
2560 · T S
7680 · T S
2192 · T S
2560 · T S
1
19760 · T S
20480 · T S
2
21952 · T S
23040 · T S
3
24144 · T S
25600 · T S
4
26336 · T S
7680 · T S
4384 · T S
5120 · T S
5
6592 · T S
4384 · T S
5120 · T S
20480 · T S
6
19760 · T S
23040 · T S
7
21952 · T S
—
—
—
8
24144 · T S
—
—
—
[0055] The above-described radio frame structure is purely exemplary and thus the number of subframes in a radio frame, the number of slots in a subframe, or the number of symbols in a slot may vary in different ways.
[0056] FIG. 3 illustrates a resource grid of one DL slot used in an LTE(-A) system.
[0057] Referring to FIG. 3 , a DL slot includes a plurality of OFDM symbols in the time domain. One DL slot may include 7 OFDM symbols and a resource block (RB) may include 12 subcarriers in the frequency domain. However, the present invention is not limited thereto. Each element of the resource grid is referred to as a Resource Element (RE). An RB includes 12×7 REs. The number of RBs in a DL slot, N DL depends on a DL transmission bandwidth. A UL slot may have the same structure as a DL slot.
[0058] FIG. 4 illustrates a downlink subframe structure used in the LTE(-A) system.
[0059] Referring to FIG. 4 , a maximum of three (four) OFDM symbols located in a front portion of a first slot within a subframe correspond to a control region to which a control channel is allocated. The remaining OFDM symbols correspond to a data region to which a physical downlink shared chancel (PDSCH) is allocated. A basic resource unit of the data region is RB. Examples of downlink control channels used in the LTE(-A) system include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), etc.
[0060] FIG. 5 illustrates a control channel allocated to a downlink subframe. In FIG. 5 , R 1 to R 4 denote a cell-specific reference signal (CRS) or a cell-common reference signal for antenna ports 0 to 3. The CRS is transmitted in all bands every subframe and fixed in a predetermined pattern in a subframe. The CRS is used to channel measurement and downlink signal demodulation.
[0061] Referring to FIG. 5 , the PCFICH is transmitted at a first OFDM symbol of a subframe and carries information regarding the number of OFDM symbols used for transmission of control channels within the subframe. The PCFICH is composed of four REGs that are uniformly distributed in a control region based on a cell ID. The PCFICH indicates a value of 1 to 3 (or 2 to 4) and is modulated via quadrature phase shift keying (QPSK).
[0062] The PHICH is a response of uplink transmission and carries an HARQ acknowledgment (ACK)/not-acknowledgment (NACK) signal. The PHICH except for CRS and PCFICH (a first OFDM symbol) is allocated on the remaining REGs in one or more OFDM symbols configured by PHICH duration. The PHICH is allocated to three REGs that are distributed if possible on the frequency domain.
[0063] In LTE system, one PHICH carries 1-bit ACK/NACK signal for PUSCH transmission (or a single data stream) of one user equipment. 1-bit ACK/NACK signal may be coded to 3 bits by using repetition coding of code rate ⅓. ACK/NACK signal through PHICH may be modulated using binary phase shift keying (BPSK). A symbol after modulation may be spread using a spreading factor=4 in case of normal CP or using a spreading factor=2 in case of extended CP. The number of orthogonal sequences used for spreading becomes (spreading factor)*2 by applying I/Q multiplexing. (spreading factor)*2 PHICHs spread using (spreading factor)*2 orthogonal sequences may be defined as one PHICH group. The PHICH group is layer-mapped, precoded, and then mapped to resources and transmitted.
[0064] The PDCCH is allocated in first n OFDM symbols (hereinafter, a control region) of a subframe. Here, n is an integer equal to or greater than 1 and is indicated by the PCFICH. Control information transmitted through the PDCCH is referred to as downlink control information (DCI). DCI format is defined as formats 0, 3, 3A, and 4 for uplink and defined as formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, and 2D for downlink. DCI format optionally includes information about hopping flag, RB allocation, modulation coding scheme (MCS), redundancy version (RV), new data indicator (NDI), transmit power control (TPC), cyclic shift demodulation reference signal (DM-RS), channel quality information (CQI) request, HARQ process number, transmitted precoding matrix indicator (TPMI), precoding matrix indicator (PMI) confirmation, etc. according to its usage.
[0065] A PDCCH may carry a transport format and a resource allocation of a downlink shared channel (DL-SCH), resource allocation information of an uplink shared channel (UL-SCH), paging information on a paging channel (PCH), system information on the DL-SCH, information on resource allocation of an upper-layer control message such as a random access response transmitted on the PDSCH, a set of Tx power control commands on individual UEs within an arbitrary UE group, a Tx power control command, information on activation of a voice over IP (VoIP), etc. The BS determines a PDCCH format according to DCI to be transmitted to the UE, and attaches a cyclic redundancy check (CRC) to control information. The CRC is masked with a unique identifier (referred to as a radio network temporary identifier (RNTI)) according to an owner or usage of the PDCCH. If the PDCCH is for a specific UE, a unique identifier (e.g., cell-RNTI (C-RNTI)) of the UE may be masked to the CRC. Alternatively, if the PDCCH is for a paging message, a paging identifier (e.g., paging-RNTI (P-RNTI)) may be masked to the CRC. If the PDCCH is for system information (more specifically, a system information block (SIB)), a system information RNTI (SI-RNTI) may be masked to the CRC. When the PDCCH is for a random access response, a random access-RNTI (RA-RNTI) may be masked to the CRC.
[0066] UE may monitor a plurality of PDCCHs. A plurality of PDCCHs may be transmitted in one subframe. The LTE(-A) system defines a limited set of resource positions in which a PDCCH is to be positioned for each UE. A limited set of resource positions that a UE can find a PDCCH of the UE may be referred to as a search space (SS). In the LTE(-A) system, the SS has different sizes according to each PDCCH format. In addition, a UE-specific SS and a common SS are separately defined. The BS does not provide the UE with information indicating where the PDCCH is located in the control region. Accordingly, the UE monitors a set of PDCCH candidates within the subframe and finds its own PDCCH. The term “monitoring” means that the UE attempts to decode the received PDCCHs according to respective DCI formats. The monitoring for a PDCCH in an SS is referred to as blind decoding (blind detection). Through blind decoding, the UE simultaneously performs identification of the PDCCH transmitted to the UE and decoding of the control information transmitted through the corresponding PDCCH. For example, in the case where the PDCCH is de-masked using the C-RNTI, the UE detects its own PDCCH if a CRC error is not detected. The USS is separately configured for each UE and a scope of CSSs is known to all UEs.
[0067] In general, the UE searches for formats 0 and 1A at all times in the UE-specific search space. Formats 0 and 1A have the same size and are discriminated from each other by a flag in a message. The UE may need to receive an additional format (e.g. format 1, 1B or 2 according to PDSCH transmission mode set by a BS). The UE searches for formats 1A and 1C in the UE-common search space. Furthermore, the UE may be set to search for format 3 or 3A. Formats 3 and 3A have the same size as that of formats 0 and 1A and may be discriminated from each other by scrambling CRC with different (common) identifiers rather than a UE-specific identifier. A PDSCH transmission scheme and information contents of DCI formats according to a transmission mode will be listed below.
[0068] Transmission Mode (TM)
Transmission Mode 1: Transmission from a single eNB antenna port Transmission Mode 2: Transmit diversity Transmission Mode 3: Open-loop spatial multiplexing Transmission Mode 4: Closed-loop spatial multiplexing Transmission Mode 5: Multi-user MIMO Transmission Mode 6: Closed-loop rank-1 precoding Transmission Mode 7: Single-antenna port (port 5) transmission Transmission Mode 8: Dual layer transmission (ports 7 and 8) or single-antenna port (port 7 or 8) transmission Transmission Modes 9 and 10: Layer transmission up to rank 8 (ports 7 to 14) or single-antenna port (port 7 or 8) transmission
[0078] DCI Format
Format 0: Resource grant for PUSCH transmission (uplink) Format 1: Resource allocation for single codeword PUSCH transmission (transmission modes 1, 2, and 7) Format 1A: Compact signaling of resource allocation for single codeword PDSCH transmission (all modes) Format 1B: Compact resource allocation for PDSCH (mode 6) using rank-1 closed-loop precoding Format 1C: Very compact resource allocation for PDSCH (e.g., paging/broadcast system information) Format 1D: Compact resource allocation for PDSCH (mode 5) using multi-user MIMO Format 2: Resource allocation for PDSCH (mode 4) of closed-loop MIMO operation Format 2A: Resource allocation for PDSCH (mode 3) of open-loop MIMO operation Format 3/3A: Power control command with 2-bit/1-bit power adjustments for PUCCH and PUSCH Format 4: Resource grant for PUSCH transmission (uplink) in a cell configured in a multi-antenna port transmission mode
[0089] A UE may be semi-statically configured via higher layer signaling for reception of PDSCH data transmission that is scheduled through the PDCCH according to ten transmission modes. Table 5 below shows a transmission mode signaled via a higher layer and configurable DCI format when a UE detects a scrambled PDCCH as a C-RNTI identifier.
[0090] FIG. 6 illustrates a structure of a UL subframe in the LTE(-A) system.
[0091] Referring to FIG. 6 , a UL subframe includes a plurality of (e.g. 2) slots. A slot may include a different number of SC-FDMA symbols according to a CP length. The UL subframe is divided into a control region and a data region in the frequency domain. The data region includes a PUSCH to transmit a data signal such as voice and the control region includes a PUCCH to transmit UCI. The PUCCH occupies a pair of RBs at both ends of the data region on a frequency axis and the RB pair frequency-hops over a slot boundary.
[0092] The PUCCH may deliver the following control information.
Scheduling request (SR): information requesting UL-SCH resources. An SR is transmitted in On-Off Keying (OOK). HARQ ACK/NACK: a response signal to a DL data packet received on a PDSCH, indicating whether the DL data packet has been received successfully. A 1-bit ACK/NACK is transmitted as a response to a single DL codeword and a 2-bit ACK/NACK is transmitted as a response to two DL codewords. CSI: feedback information regarding a DL channel. CSI includes a CQI and Multiple Input Multiple Output (MIMO)-related feedback information includes an RI, a PMI, a Precoding Type Indicator (PTI), etc. The CSI occupies 20 bits per subframe.
[0096] Table 3 below illustrates a mapping relationship between PUCCH formats and UCI in the LTE system.
[0000]
TABLE 3
PUCCH
format
Uplink Control Information, UCI
Format 1
SR(Scheduling Request) (un-modulated waveform)
Format 1a
1-bit HARQ ACK/NACK (with/without SR)
Format 1b
2-bit HARQ ACK/NACK (with/without SR)
Format 2
CSI (20 coded bits)
Format 2
CSI and ½-bit HARQ ACK/NACK (20 bits)(Extended CP only)
Format 2a
CSI and 1-bit HARQ ACK/NACK (20 + 1 coded bits)
Format 2b
CSI and 2-bit HARQ ACK/NACK (20 + 2 coded bits)
Format 3
HARQ ACK/NACK + SR (48 bits)
(LTE-A)
[0097] FIG. 7 illustrates an example of PHICH/UL grant (UG)-PUSCH timing. PUSCH can be transmitted in response to PDCCH (UL grant) and/or PHICH (NACK).
[0098] Referring to FIG. 7 , a user equipment can receive PDCCH (UL grant) and/or PHICH (NACK) (S 702 ). In this case, NACK corresponds to ACK/NACK response for a previous PUSCH transmission. In this case, a user equipment undergoes a process (e.g., transport block (TB) coding, transport block-codeword (CW) swapping, PUSCH resource allocation and the like) for PUSCH transmission and may be able to initially transmit/retransmit one or a plurality of transport blocks via PUSCH after a k subframe (S 704 ). The present example assumes a normal HARQ operation that transmits PUSCH one time. In this case, PHICH/UL grant corresponding to the PUSCH transmission exists in an identical subframe. Yet, in case of performing subframe bundling in a manner that PUSCH is transmitted several times via a plurality of subframes, the PHICH/UL grant corresponding to the PUSCH transmission may exist in a subframe different from each other.
[0099] Specifically, if the PHICH/UL grant is detected in a subframe n, a user equipment can transmit PUSCH in a subframe n+k. in case of FDD system, k may have a fixed value (e.g., 4). In case of TDD system, k may have a different value according to a UL-DL configuration. Table 4 shows an UAI (uplink association index) (k) for PUSCH transmission in TDD LTE(-A) system.
[0000]
TABLE 4
TDD
subframe number n
UL/DL Configuration
0
1
2
3
4
5
6
7
8
9
0
4
6
4
6
1
6
4
6
4
2
4
4
3
4
4
4
4
4
4
5
4
6
7
7
7
7
5
[0100] FIG. 8 illustrates an example of PUSCH-PHICH/UL grant timing. PHICH is used to transmit DL ACK/NACK. In this case, the DL ACK/NACK indicates ACK/NACK transmitted in DL in response to UL data (e.g., PUSCH).
[0101] Referring to FIG. 8 , a user equipment transmits a PUSCH signal to a base station (S 802 ). In this case, the PUSCH signal is used to transmit one or a plurality of (e.g., 2) transport blocks (TBs) according to a transmission mode. A base station undergoes a process (e.g., ACK/NACK generation, ACK/NACK resource allocation and the like) to transmit ACK/NACK and may be then able to transmit the ACK/NACK to a user equipment via PHICH after a k subframe in response to the PUSCH transmission (S 804 ). The ACK/NACK includes reception response information on the PUSCH signal of the step S 702 . If a response for the PUSCH transmission corresponds to NACK, a base station can transmit UL grant PDCCH to a user equipment to transmit PUSCH again after the k subframe (S 804 ). The present example assumes a normal HARQ operation that transmits PUSCH one time. In this case, PHICH/UL grant corresponding to the PUSCH transmission can be transmitted in an identical subframe. Yet, in case of performing subframe bundling, the PHICH/UL grant corresponding to the PUSCH transmission can be transmitted in a subframe different from each other.
[0102] Specifically, the PHICH/UL grant of a subframe i corresponds to PUSCH transmitted in a subframe i−k. In case of TDD system, k may have a different value according to a UL-DL configuration. Table 5 shows an UAI (uplink association index) (k) for PUSCH transmission in LTE(-A) system. Table 5 shows an interval between a DL subframe and a UL subframe associated with the DL subframe in terms of the DL subframe in which PHICH/UL grant exists.
[0000]
TABLE 5
TDD
subframe number i
UL/DL Configuration
0
1
2
3
4
5
6
7
8
9
0
7
4
7
4
1
4
6
4
6
2
6
6
3
6
6
6
4
6
6
5
6
6
6
4
7
4
6
[0103] In the following, PHICH resource allocation is explained. If PUSCH is transmitted in a subframe #n, a user equipment determines a corresponding PHICH resource in a subframe #(n+k PHICH ). In FDD system, k PHICH has a fixed value (e.g., 4). In TDD system, k PHICH has a different value according to UL-DL configuration. Table 6 shows a k PHICH value for TDD.
[0000]
TABLE 6
TDD
UL subframe index n
UL/DL Configuration
0
1
2
3
4
5
6
7
8
9
0
4
7
6
4
7
6
1
4
6
4
6
2
6
6
3
6
6
6
4
6
6
5
6
6
4
6
6
4
7
[0104] FIG. 9 illustrates an example in which a DL physical channel is allocated in a subframe.
[0105] Referring to FIG. 9 , a PDCCH (for convenience, legacy PDCCH or L-PDCCH) used in the LTE(-A) system may be allocated to a control region (refer to FIG. 5 ) of a subframe. In FIG. 9 , an L-PDCCH region refers to a region to which the legacy PDCCH is allocated. In the context, the L-PDCCH region may refer to a control region, a control channel resource region to which a PDCCH can be actually allocated, or a PDCCH search space. A PDCCH may be additionally allocated in a data region (e.g., a resource region for a PDSCH, refer to FIG. 5 ). The PDCCH allocated to the data region is referred to as an E-PDCCH. As illustrated in FIG. 9 , a control channel resource may be additionally allocated through the E-PDCCH to alleviate scheduling restrictions due to limited control channel resource of an L-PDCCH region.
[0106] In detail, the E-PDCCH may be detected/demodulated based on a DM-RS. The E-PDCCH may be configured to be transmitted over a PRB pair on the time axis. In more detail, a search space (SS) for E-PDCCH detection may be configured with one or more (e.g., 2) E-PDCCH candidate sets. Each E-PDCCH set may occupy a plurality of (e.g., 2, 4, or 8) PRB pairs. An enhanced-CCE (E-CCE) constituting an E-PDCCH set may be mapped in the localized or distributed form (according to whether one E-CCE is distributed in a plurality of PRB pairs). In addition, when E-PDCCH based scheduling is configured, a subframe for transmission/detection of an E-PDCCH may be determined The E-PDCCH may be configured in only a USS. The UE may attempt DCI detection only on an L-PDCCH CSS and an E-PDCCH USS in a subframe (hereinafter, an E-PDCCH subframe) in which E-PDCCH transmission/detection is configured and attempt DCI detection on an L-PDCCH CSS and an L-PDCCH USS in a subframe (non-E-PDCCH subframe) in which transmission/detection of E-PDCCH is not configured.
[0107] In the LTE system and LTE-A system, a series of processes for scheduling UEs by an eNB and transmitting and receiving data to and from the UEs through the eNB are performed for communication between the UEs. On the other hand, a communication method for directly transmitting and receiving data to and from UEs without an eNB is referred to as device-to-device (D2D) communication. In a D2D communication system, data is directly transmitted between UEs but control of an eNB may be partially performed. The present invention proposes a D2D data scheduling/transmitting procedure and a feedback procedure appropriate therefor in this D2D communication situation. For convenience of description, devices that perform D2D data transmitting/receiving operations on a D2D communication link may be referred to as a transmitting device or transmitter device (TD) and a receiving device or a receiver device (RD), respectively. The type of the PDCCH stated according to the present invention may be based on an E-PDCCH manner as well as an L-PDCCH method. In addition, for convenience of description, although the present invention will be described using a PDCCH, a PDSCH, a PHICH, and a PUCCH, a channel/signal corresponding to each of the PDCCH, the PDSCH, the PHICH, and the PUCCH can be replaced with another title of channel/signal that performs the same function.
[0108] FIG. 10 illustrates an example of a D2D data scheduling/transmitting procedure to be performed in a D2D communication situation that can be generally considered.
[0109] Referring to FIG. 10 , an eNB 1010 may semi-statically pre-configure control information/parameters, etc. required for D2D communication to D2D UEs 1020 and 1030 via higher layer signaling (e.g., RRC signaling) (S 1002 and S 1004 ). For example, the control information/parameters required for D2D communication may include information about a subframe set (referred to as a “D2D SF set”) in which D2D signal transmission is possible/permitted and/or information about a subframe set (referred to as a “D2D-BD SF set”) in which signaling of D2D scheduling information transmitted and received between D2D UEs can be performed/detected (e.g., blind-detected (BD)). For example, the D2D-BD SF set may be configured as a specific subset of the D2D SF set.
[0110] Then the eNB 1010 may dynamically transmit a specific control signal/channel or data channel for triggering D2D scheduling at a specific time point to the TD 1020 and the RD 1030 (S 1006 and S 1008 ). In this case, the control signal/channel for triggering D2D scheduling may be transmitted through, for example, a PDCCH and the data channel for triggering D2D scheduling through, for example, a PDSCH. For convenience, in this specification, the specific control signal/channel or data channel for triggering D2D scheduling is referred to as a D2D trigger.
[0111] The TD 1020 and the RD 1030 that receive the D2D trigger may perform a D2D data transmitting and receiving operation to the RD 1030 from the TD 1020 based on D2D communication control information/parameter that is pre-configured via higher layer signaling and D2D scheduling control information in the D2D trigger (S 1012 ). In this case, detailed D2D scheduling information such as resource allocation information, a modulation and coding scheme (MCS), and/or a size of a transport block (TB) for D2D data transmission and reception may be transmitted and received between the D2D UEs (TD and RD) 1020 and 1030 (S 1010 ). For example, the detailed D2D scheduling information for D2D data transmission and reception may be signaled to the RD 1030 from the TD 1020 or signaled to the TD 1020 from the RD 1030 . Then the RD 1030 may transmit ACK/NACK feedback to D2D data reception to the eNB 1010 or the TD 1020 .
[0112] In the example of FIG. 10 , operation S 1010 may be performed at the same time point as operation S 1012 or performed at a specific time point prior to operation S 1012 .
[0113] The D2D data scheduling/transmitting procedure illustrated in FIG. 10 may be appropriate for, for example, the case in which a stable link between an eNB and TD/RD is ensured. In this specification, a link may be a communication channel configured between a transmitter and a receiver and referred to as a radio link.
[0114] FIG. 11 illustrates an example of a D2D data scheduling/transmitting procedure to be performed in another D2D communication situation.
[0115] Referring to FIG. 11 , the eNB 1010 may semi-statically pre-configure control information/parameters required for D2D communication to the D2D UEs 1020 and 1030 via higher layer signaling (e.g., RRC signaling) (S 1002 and S 1004 ). For example, the control information/parameters required for D2D communication may include information about a D2D SF set in which D2D signal transmission is possible/permitted and/or information about a D2D-BD SF set in which signaling of D2D scheduling information transmitted and received between D2D UEs can be performed/detected (e.g., blind-detected (BD)). For example, the D2D-BD SF set may be configured as a specific subset of the D2D SF set.
[0116] Then the eNB 1010 may dynamically transmit a D2D trigger for triggering D2D scheduling at a specific time point only to the TD 1020 (S 1006 ). As described above, the D2D trigger may be transmitted through a specific control signal/channel such as a PDCCH, etc. or a data channel such as a PDSCH, etc.
[0117] After receiving a D2D trigger, the TD 1020 may signal detailed D2D scheduling information for D2D data transmission and reception to the RD 1030 based on pre-configured D2D communication control information/parameters and D2D scheduling in the D2D trigger, in a specific subframe of the D2D-BD SF set (S 1110 ). The detailed D2D scheduling information may include information such as resource allocation information, modulation and coding scheme (MCS), and/or a size of transport block (TB).
[0118] In a specific subframe of the D2D SF set, the TD 1020 may perform a D2D data transmission operation to the RD 1030 (S 1012 ). In this case, the RD 1030 may attempt to detect/receive D2D scheduling information signaling for a designated D2D-BD SF set. As described above, a specific subset of the D2D SF set may be configured as a D2D-BD SF set. Then the RD 1030 may transmit ACK/NACK feedback to D2D data reception to the eNB 1010 or the TD 1020 .
[0119] Although FIG. 11 illustrates the case in which operations S 1110 and S 1012 are performed at different time points, operations S 1110 and S 1012 may be performed at the same time point.
[0120] The D2D data scheduling/transmitting procedure illustrated in FIG. 11 may be appropriate for, for example, the case in which a stable link between a TD and an eNB is ensured but a stable link between an RD and the eNB is not ensured. For example, when the RD is outside eNB coverage, a stable link between the RD and the eNB may not be ensured.
[0121] In a D2D communication system, an ACK/NACK feedback transmission method for D2D data may include a method for transmitting the D2D data to an eNB from an RD and a method for transmitting the D2D data to a TD from the RD. For convenience, a method for transmitting ACK/NACK feedback to D2D data reception to an eNB from an RD is referred to as an A/N-to-eNB method and a method for transmitting ACK/NACK feedback to D2D data reception to the TD from the RD is referred to as an A/N-to-TD method. The present invention proposes D2D feedback procedures appropriate for the respective ACK/NACK feedback transmission methods.
[0122] D2D Feedback Procedure Based on A/N-to-eNB Method
[0123] In the A/N-to-eNB method, after D2D scheduling, an eNB may receive ACK/NACK feedback to D2D data reception from an RD. When the ACK/NACK feedback is ACK, no problem occurs, but when the ACK/NACK feedback is NACK, it may be difficult to determine the reason. For example, when the ACK/NACK feedback is NACK, the reason may corresponds to the case in which (i) although a TD transmits D2D data, receiving errors arise in an RD, or (ii) although the TD does not transmit D2D data, the RD determines receiving errors, and thus the reason may be ambiguous. Thus, upon receiving NACK, the eNB may have difficulty in determining whether link performance between the TD and the RD needs to be supplemented or link performance between the eNB and the TD needs to be supplemented. For example, in order to supplement the link performance between the TD and the RD, power/resource/MCS/RV, etc. for D2D data transmission may be adjusted. In addition, for example, in order to supplement the link performance between the eNB and the TD, power/resource/MCS/RV, etc. for D2D trigger transmission may be adjusted.
[0124] To overcome this problem, the present invention proposes a method of feeding back information about whether the TD actually transmits D2D data to the RD based on D2D scheduling information received from the eNB, to the eNB. For convenience of description, a signal about whether D2D data is transmitted, which is fed back to an eNB by a TD, is referred to as “TX feedback”.
[0125] In detail, TX feedback may have two states similarly to ACK/NACK feedback fed back to an eNB from an RD. For example, the two states for the TX feedback may include TX success or TX failure. In addition, for example, when the TD performs D2D data transmission to the RD, the TX success may be signaled to the eNB, and when the TD does not perform D2D data transmission to the RD, the TX failure may be signaled to the eNB. For example, the TX failure may be useful to the case in which a TD gives up D2D data transmission in order to transmit and receiving a signal/channel with higher priority than D2D data although the TD properly receives a D2D trigger. A signal/channel used for the TX feedback may have the same/similar format (e.g., PUCCH format 1a/1b) to a signal/channel for ACK/NACK feedback. For example, different TX feedback states may be mapped to positions of ACK and NACK on constellation. In addition, TX feedback may be transmitted after D2D data is transmitted. In addition, the TX feedback may be transmitted at the same time point as ACK/NACK feedback based on the A/N-to-eNB method or transmitted at a time point prior to ACK/NACK feedback.
[0126] In the A/N-to-eNB method, since ACK/NACK feedback to D2D data is transmitted to an eNB, but not to the TD, from the RD, the TD cannot recognize whether reception/decoding in the RD is successful with respect to transmitted D2D data. Thus, the TD needs to unnecessarily continuously store the D2D data in a transmission buffer for a predetermined period of time and needs to also allow hardware required for a D2D transmission operation (e.g., SC-FDM modulation based transmission) to wait while being continuously driven, which may not be appropriate in terms of buffer usage efficiency and power consumption reduction.
[0127] To overcome this problem, the present invention proposes that an eNB feedback information about whether the RD succeeds in receiving/decoding D2D data to a TD and/or an RD based on ACK/NACK feedback from the RD. For convenience, a signal that is fed back to the TD and/or the RD from the eNB in order to indicate whether D2D data reception/decoding are successful is referred to as “RX feedback”.
[0128] In detail, the RX feedback may have two states similarly to ACK/NACK feedback fed back to an eNB from an RD. For example, the two states for the RX feedback may include RX success or RX failure. In addition, for example, when the RD succeeds in receiving/decoding D2D data, the RX success may be signaled to the TD. The case in which the RD succeeds in receiving/decoding D2D data may include, for example, the case in which ACK/NACK feedback is ACK. In addition, for example, when the RD fails in receiving/decoding D2D data, the RX failure may be signaled to the TD. The case in which the RD fails in receiving/decoding D2D data may include, for example, the case in which ACK/NACK feedback is NACK and/or discontinuous transmission (DTX). The DTX may include the case in which detection of ACK/NACK feedback signal from the RD fails and/or the case in which the RD fails in detecting D2D scheduling information signaling from the TD.
[0129] Alternatively, the RX feedback may have three states. For example, the three states for the RX feedback may include RX success, RX fail-wait, and RX fail-retx. The RX success may be the same as the aforementioned RX success. The RX fail-wait may be signaled to the TD when the RD fails in receiving/decoding D2D data. In this case, the TD may attempt to detect a D2D trigger for retransmission of D2D data without automatic retransmission of the D2D data. The RX fail-retx may be signaled to the TD when the RD fails in receiving/decoding the D2D data. In this case, the TD may automatically retransmit the D2D data based on a most recently received D2D trigger. The case in which the RD fails in receiving/decoding the D2D data may include, for example, the case in which ACK/NACK feedback is NACK.
[0130] A signal/channel used for the RX feedback may be a PDCCH having, for example, the same or similar format to a DCI format (e.g., DCI format 3/3A) for PHICH or UL power control. For example, 2-state RX feedback can be represented by one bit, and thus one bit can be allocated/used in one PHICH resource or DCI format 3/3A. As another example, 3-state RX feedback can be represented by two bits, and thus two bits can be allocated/used in two PHICH resources or DCI format 3/3A. When a PDCCH (e.g., DCI format 3/3A) is used, each RX feedback state may be configured or divided using a combination of the bits values. When a PHICH is used, each RX feedback state may be configured or divided using a combination of ACK/NACK modulation symbols on each PHICH resource.
[0131] Although the TX feedback and the RX feedback have been separately described thus far, the TX feedback and the RX feedback can simultaneously applied for management of eNB-TD/RD and TD-RD link and buffer and power management of a D2D UE.
[0132] FIG. 12 illustrates an example of a D2D feedback procedure according to the present invention. In the example of FIG. 12 , it is assumed that the eNB 1010 semi-statically pre-configures control information/parameters required for D2D communication to the D2D UEs 1020 and 1030 via higher layer signaling (e.g., RRC signaling) (refer to S 1002 and S 1004 of FIG. 10 or 11 ).
[0133] As described with reference to FIG. 10 , in operations S 1202 and S 1204 , the eNB 1010 may dynamically transmit a D2D trigger to the TD 1020 and the RD 1030 at a specific time point (refer to S 1006 and S 1008 of FIG. 10 ). Alternatively, as described with reference to FIG. 11 , the eNB 1010 may dynamically transmit a D2D trigger only to the TD 1020 at a specific time point (refer to S 1006 of FIG. 11 ). In this case, operation S 1204 may not be performed. As described above, the D2D trigger may be transmitted through, for example, a PDCCH or a PDSCH.
[0134] In operation S 1206 , the TD 1020 may transmit D2D data to the RD 1030 . The D2D transmission to the RD 1030 from the TD 1020 may be based on D2D communication control information/parameters pre-configured via higher layer signaling and D2D scheduling control information in a D2D trigger.
[0135] In addition, as described with reference to FIGS. 10 and 11 , simultaneously with operation S 1206 or prior to operation S 1206 , the TD 1020 may signal detailed D2D scheduling information such as resource allocation information, a modulation and coding scheme (MCS), and/or a size of a transport block (TB) for D2D data transmission and reception, to the RD 1030 .
[0136] In operation S 1208 , the TD 1020 may transmit TX feedback to the eNB 1010 . As described above, the TX feedback may include information about whether the TD actually transmits D2D data to the RD. In addition, the TX feedback may include a plurality of state information and for example, include two state information such as TX success and TX failure.
[0137] In operation S 1210 , the RD 1030 may transmit ACK/NACK feedback to D2D data to the eNB 1010 . The ACK/NACK feedback may indicate whether the RD succeeds in receiving/decoding the D2D data transmitted from the TD. The ACK/NACK feedback may include, for example, two state information such as ACK and NACK or three state information such as ACK, NACK, and DTX.
[0138] As described above, operations S 1208 and S 1210 may be performed at the same time point. Alternatively, operations S 1208 and S 1210 may be performed at different time points. For example, operation S 1208 may be performed prior to operation S 1210 .
[0139] In operation S 1212 , the eNB 1010 may transmit RX feedback to the TD 1020 . As described above, the RX feedback may include information about whether D2D data reception/decoding fed back to the TD and/or the RD are successful. In addition, the RX feedback may include a plurality of state information, for example, two state information such as RX success and RX fail or three state information such as RX success, RX fail-wait, and RX fail-retx. Upon receiving RX feedback including RX fail-wait, the TD 1020 may attempt to detect a D2D trigger for retransmission of D2D data without automatic retransmission of the D2D data. Upon receiving RX feedback including RX fail-retx, the TD 1020 may automatically retransmit D2D data based on a most recently received D2D trigger.
[0140] D2D Feedback Procedure Based on A/N-to-TD Method
[0141] In the A/N-to-TD method, after D2D scheduling, a TD directly receives ACK/NACK feedback to D2D data transmitted to an RD from the TD from the RD. In this case, when an eNB can know an ACK/NACK feedback state, the A/N-to-TD method may also be useful for management of eNB-RD link, management of TD-RD transmission link, and management of RD-TD feedback link as well as for management of scheduling/resource of D2D UEs. For example, when it is assumed that the eNB knows ACK/NACK feedback to D2D data, if ACK/NACK feedback is ACK, the eNB may appropriately re-adjust a D2D scheduling/resource allocation sequence of the TD/RD to, for example, a subordinated sequence. In addition, when the ACK/NACK feedback is NACK, the eNB may supplement D2D data transmission link performance between the TD and the RD (e.g., via adjustment of power/resource/MCS/RV). In addition, in the case of DTX (which corresponds to the case in which ACK/NACK feedback signal detection from the RD fails), the eNB may supplement D2D trigger transmission link between the eNB and RD or ACK/NACK feedback link performance between the RD and the TD (e.g., via adjustment of power/resource/MCS/RV).
[0142] To this end, the present invention proposes a method in which the TD transmits ACK/NACK feedback information to D2D data received from the RD by the TD, to the eNB. For convenience, a signal for transmitting ACK/NACK feedback information to the eNB by the TD is referred to as “ACK/NACK forward”.
[0143] In detail, the ACK/NACK forward may have two states similarly to ACK/NACK feedback. For example, the two states for the ACK/NACK forward may include D2D-ACK and D2D-NACK. The D2D-ACK may be signaled to the eNB from the TD when the ACK/NACK feedback received from the RD is ACK. The D2D-NACK may be signaled to the eNB from the TD when the ACK/NACK feedback received from the RD is NACK or DTX.
[0144] Alternatively, the ACK/NACK forward may have three states. For example, the three states for the ACK/NACK forward may include D2D-ACK, D2D-NACK, or D2D-DTX. The D2D-ACK may be signaled to the eNB from the TD when the ACK/NACK feedback received from the RD is ACK. The D2D-NACK may be signaled to the eNB from the TD when the ACK/NACK feedback received from the RD is NACK. The D2D-DTX may be signaled to the eNB from the TD when the ACK/NACK feedback received from the RD is DTX.
[0145] A signal/channel used for the ACK/NACK forward may have the same/similar format (e.g., PUCCH format 1a/1b) to a signal/channel for ACK/NACK feedback. For example, different ACK/NACK forward states may be mapped to positions of ACK and NACK on constellation.
[0146] FIG. 13 illustrates an example of a D2D feedback procedure according to the present invention. In the example of FIG. 13 , it is assumed that the eNB 1010 may semi-statically pre-configure control information/parameters required for D2D communication to the D2D UEs 1020 and 1030 via higher layer signaling (e.g., RRC signaling) (refer to S 1002 and S 1004 of FIG. 10 or 11 ).
[0147] Operations S 1202 , S 1204 , and S 1206 are the same as those described with reference to FIG. 12 . Thus, the description of operations S 1202 , S 1204 , and S 1206 is applied herein. In addition, as described with reference to FIG. 12 , simultaneously with operation S 1206 or prior to operation S 1206 , the TD 1020 may signal detailed D2D scheduling information for D2D data transmission and reception to the RD 1030 .
[0148] In operation S 1308 , the RD 1030 may transmit ACK/NACK feedback to the TD. As described above, the ACK/NACK feedback may indicate whether the RD succeeds in receiving/decoding the D2D data transmitted from the TD. The ACK/NACK feedback may include, for example, two state information such as ACK and NACK or three state information such as ACK, NACK, and DTX.
[0149] In operation S 1310 , the TD 1020 may transmit ACK/NACK forward to the eNB 1010 . As described above, the ACK/NACK forward may refer to feedback information for transmitting ACK/NACK feedback information about D2D data, received from the RD by the TD, to the eNB from the TD. In addition, the ACK/NACK forward may include a plurality of state information, and for example, include two and three state information according to a state of the ACK/NACK feedback received from the RD.
[0150] Since a stable link between the RD and the eNB is not ensured in the method illustrated in FIG. 13 , the method may be useful when the RD cannot receive a D2D trigger from the eNB or the RD transmits ACK/NACK feedback to D2D data to the eNB. The case in which the stable link between the RD and the eNB is not ensured may include, for example, the case in which the RD is outside coverage of the eNB.
[0151] In addition, the method illustrated in FIG. 13 may be useful when overall configuration and/or control required for D2D communication is managed in terms of the eNB and the TD. The case in which overall configuration and/or control required for D2D communication is managed in terms of the eNB and the TD may include, for example, the case in which the TD is used as a relay node between the eNB and the RD.
[0152] Thus far, the D2D feedback procedure based on the A/N-to-eNB method and the D2D feedback procedure based on the A/N-to-TD method have been described. The two D2D feedback procedures may be independently performed and some components may be omitted or other components are added during each D2D feedback procedure. In addition, the two D2D feedback procedures may be combined and performed and some components of one D2D feedback procedure may be combined with the other D2D feedback procedure or all components of one D2D feedback procedure may be combined with the other D2D feedback procedure during each D2D feedback procedure.
[0153] For example, the RX feedback of the A/N-to-eNB method may be combined with the D2D feedback procedure of the A/N-to-TD method. In this case, the TD may receive the RX feedback from the eNB so as to clearly recognize whether the eNB receives ACK/NACK forward transmitted from the TD. In addition, when RX fail-retx is received, signaling for D2D data retransmission may be reduced, and thus the method according to this example may be useful.
[0154] Another example, when the A/N-to-eNB method and the A/N-to-TD method are entirely combined and used, the eNB may dynamically or semi-statically indicate information about a used method of the A/N-to-eNB method and the A/N-to-TD method according to a situation. When the eNB dynamically indicates the information, the information may be indicated through, for example, a D2D trigger such as a PDCCH or a PDSCH. When the eNB semi-statically indicates the information, the information may be indicated via higher layer signaling, for example, RRC.
[0155] Information about resource and transmission time for transmission of TX feedback, RX feedback, and ACK/NACK forward as well as the ACK/NACK feedback may be pre-configured via higher layer signaling (e.g., RRC signaling) or indicated via a D2D trigger such as PDCCH/PDSCH, etc.
[0156] FIG. 14 is a diagram illustrating a BS 110 and a UE 120 to which the present invention is applicable.
[0157] Referring to FIG. 14 , a wireless communication system includes the BS 110 and the UE 120 . When the wireless communication system includes a relay, the BS 110 or the UE 120 can be replaced with the relay.
[0158] The BS 110 includes a processor 112 , a memory 114 , and a radio frequency (RF) unit 116 . The processor 112 may be configured to embody the procedures and/or methods proposed by the present invention. The memory 114 is connected to the processor 112 and stores various pieces of information associated with an operation of the processor 112 . The RF unit 116 is connected to the processor 112 and transmits/receives a radio signal. The UE 120 includes a process 122 , a memory 124 , and an RF unit 126 . The processor 122 may be configured to embody the procedures and/or methods proposed by the present invention. The memory 124 is connected to the processor 122 and stores various pieces of information associated with an operation of the processor 122 . The RF unit 126 is connected to the processor 122 and transmits/receives a radio signal.
[0159] The embodiments of the present invention described above are combinations of elements and features of the present invention. The elements or features may be considered selective unless otherwise mentioned. Each element or feature may be practiced without being combined with other elements or features. Further, an embodiment of the present invention may be constructed by combining parts of the elements and/or features. Operation orders described in embodiments of the present invention may be rearranged. Some constructions of any one embodiment may be included in another embodiment and may be replaced with corresponding constructions of another embodiment. It is obvious to those skilled in the art that claims that are not explicitly cited in each other in the appended claims may be presented in combination as an embodiment of the present invention or included as a new claim by a subsequent amendment after the application is filed.
[0160] Specific operations to be conducted by the base station in the present invention may also be conducted by an upper node of the base station as necessary. In other words, it will be obvious to those skilled in the art that various operations for enabling the base station to communicate with the terminal in a network composed of several network nodes including the base station will be conducted by the base station or other network nodes other than the base station. The term “base station (BS)” may be replaced with a fixed station, Node-B, eNode-B (eNB), or an access point as necessary. The term “terminal” may also be replaced with a user equipment (UE), a mobile station (MS) or a mobile subscriber station (MSS) as necessary.
[0161] The embodiments of the present invention may be achieved by various means, for example, hardware, firmware, software, or a combination thereof. In a hardware configuration, an embodiment of the present invention may be achieved by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSDPs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.
[0162] In a firmware or software configuration, an embodiment of the present invention may be implemented in the form of a module, a procedure, a function, etc. Software code may be stored in a memory unit and executed by a processor. The memory unit is located at the interior or exterior of the processor and may transmit and receive data to and from the processor via various known means.
[0163] 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 spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
INDUSTRIAL APPLICABILITY
[0164] The present invention is applicable to a wireless communication apparatus such as a user equipment (UE), a base station (BS), etc.
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The present invention relates to a wireless communication system. More specifically, the present invention relates to a method for transreceiving a control signal from a first terminal in the wireless communication system which supports device-to-device (D2D) communication and an apparatus for same, the method comprising the steps of: receiving from a base station a signal which triggers the D2D communication between the first terminal and a second terminal; transmitting data to the second terminal; receiving from the second terminal an acknowledgement/non-acknowledgement (ACK/NACK) signal with respect to the data; and transmitting to the base station an ACK/NACK delivery signal for delivering the ACK/NACK signal to the base station.
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BACKGROUND OF THE INVENTION
1. Field of The Invention
The subject invention relates to displaying images having a certain aspect ratio on display screens having a different aspect ratio.
2. Description of The Related Art
With the advent of widescreen displays in which the display screen has an aspect ratio of 16:9, a problem has arisen when images having an aspect ratio of 4:3 are displayed on the screen. In particular, as shown in FIG. 1A, the 4:3 aspect ratio image 1 is displayed on the screen with vertical black bands 2 and 3 . Since at the present time, most video signals have the 4:3 aspect ratio, “burn in” may occur on the display screen where the screen phosphors are aged only in the area where the image is displayed. This then leads to distortions when viewing a true 16:9 image on the display.
Similarly, motion pictures are generally shot in a 16:9 aspect ratio. However, when that picture is reformatted for the standard 4:3 aspect ratio, information is lost. Now many motion picture studios release these motion pictures also in “letterbox” format in which the 16:9 image is compressed such that it fits the 4:3 aspect ratio. This is shown in FIG. 1B where the 16:9 image 4 appears between two horizontal black bands 5 and 6 .
In addition to being detrimental to the display, the appearance of these vertical or horizontal black bands is disturbing to the user of the display and detracts from the viewing experience.
Conversion circuitry is know that is capable of expanding a displayed image both horizontally and vertically in order to eliminate these black bands. However, it is up to the user to decide when and which of these conversions is to be used.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a method and apparatus for automatically eliminating both horizontal and vertical black bands from the borders of displayed images.
This object is achieved in a method for automatically eliminating horizontal and vertical black bands from the borders of a displayed video image, the method comprising the steps of performing a first detection of the occurrence of a black level in an input video signal for at least n lines at the beginning and end of a frame in the input video signal; performing a second detection of the occurrence of a black level in said input video signal for at least m pixels at the beginning and end of each line in a frame of the input video signal; vertically up-converting the lines in the input video signal in dependence on said first detection; and horizontally expanding the lines in the input video signal in dependence on said detection.
An apparatus for automatically eliminating horizontal and vertical black bands from the borders of a displayed video image, comprises first means for performing a first detection of the occurrence of a black level in an input video signal for at least n lines at the beginning and end of a frame in the video signal; second means for performing a second detection of the occurrence of a black level in an input video signal for at least m pixels at the beginning and end of each line in the video signal; means for vertically up-converting the lines in the video signal in dependence on said first detection; and means for horizontally expanding the lines in the video signal in dependence on said detection.
In a preferred embodiment of the invention, the first and second detections are performed for a predetermined number of fields (or frames) to insure that the black bands consistently persist. It should be understood that with this preferred embodiment, the black bands will appear on the display at least temporarily.
In order to prevent the black bands from being temporarily visible, the above method may alternatively include delaying the input video signal for at least one field (or frame) while the black level detection is being performed.
BRIEF DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in mind as will hereinafter appear, the invention will be described with reference to the accompanying drawings, in which:
FIGS. 1A and 1B show illustrations of video displays with black bands appearing vertically on opposite ends and appearing horizontally at the top and bottom of respective video displays;
FIG. 2 shows a block diagram of an embodiment of the invention;
FIGS. 3A and 3B show an embodiment of the black level detector of FIG. 2; and
FIGS. 4A and 4B show embodiments of the vertical and horizontal black band detectors of FIG. 3 B.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 2, the apparatus is shown having an input for receiving an input video signal which is applied to an analog-to-digital (A/D) converter 10 . The digitized video signal is then applied to a field (or frame) delay 12 and then to an input of a demultiplexer 14 . The demultiplexer 14 has a first output connected to a vertical scan converter 16 , a second output connected to a horizontal line expander 18 , and a third output. A multiplexer 20 is also provided and includes a first input connected to an output of the vertical scan converter 16 , a second input connected to an output of the horizontal line expander 18 , and a third input connected to the third output of the demultiplexer 14 . The output from the multiplexer 20 is connected to a digital-to-analog (D/A) converter 22 , the output therefrom forming the output of the apparatus.
A black level detector 24 is provided for detecting a black level in the input video signal. To that end, an input of the black level detector 24 is connected to the output of the A/D converter 10 . A synchronization signal separator 26 is connected to the input to receive the input video signal and supplies horizontal (H) and vertical (V) synchronization signals to the black level detector 24 . If the black level detector 24 detects the black level for the first and last, for example, 20 lines in a frame (or the first and last 10 lines in a field) of the input video signal, the black level detector 24 causes the demultiplexer 14 to apply the delayed video signal to the vertical scan converter 16 , and the multiplexer 20 to apply the output from the vertical scan converter 16 to the D/A converter 22 . Similarly, if the black level detector 24 detects the black level for the first and last, for example, 20 pixels in each line in a frame (or field) of the input video signal, the black level detector 24 causes the demultiplexer 14 to apply the delayed video signal to the horizonal line expander 18 , and the multiplexer 20 to apply the output from the horizontal line expander to the D/A converter 22 . Of course, if the black level detector 24 does not detect the black level as such, the demultiplexer 14 applies the delayed video signal directly to the multiplexer 20 which, in turn, applies the delayed video signal to the D/A converter 22 .
In an alternative embodiment, the field/frame delay 12 is omitted while the black level detector 24 examines the input video signal and does not switch the demultiplexer 14 or the multiplexer 20 until it detects the appropriate condition for several consecutive frames (or fields).
FIGS. 3A and 3B show an embodiment of the black level detector 24 . As shown in FIG. 3A, the digitized video signal is filtered in a median horizontal low-pass filter 30 , and a median vertical low-pass filter 31 to remove burst noise. A threshold detector 32 then provides a “0” output for all video pixel samples less than a threshold level, e.g., 5 , and a “1” output for all video pixel samples greater than or equal to the threshold level. This reduces the incoming video image to a series of “0” and “1” values. It is expected that in the blank parts of the screen, these values would be “0”.Of course, there may be “0” values naturally occurring within the actual video signal. The output from the threshold detector 32 is further smoothed by another series of median horizontal and vertical low-pass filters 33 and 34 , to remove any spurious transitions.
FIG. 3B shows, in block diagram form, circuitry for detecting the left and right black bands as well as the top and bottom black bands. In particular, the output A from the median vertical low-pass filter 34 and the horizontal and vertical synchronization signals H and V are applied to a vertical black band detector 35 , for detecting the black bands 2 and 3 shown in FIG. 1A, and to a horizontal black band detector 36 , for detecting the black bands 5 and 6 in Fig. 1 B. The outputs from the vertical and horizontal black band detectors 35 and 36 are applied to a logic circuit 37 which, in turn, applies a switching signal to the demultiplexer 14 and the multiplexer 20 . In particular, if the output from the vertical black band detector 35 is “1”, the logic circuit 37 switches the demultiplexer 14 and the multiplexer 20 to the horizontal scan converter 18 . Similarly, if the output from the horizontal black band detector 36 is “1”,the logic circuit 37 switches the demultiplexer 14 and the multiplexer 20 to the vertical scan converter 16 . If the outputs from the vertical and horizontal black band detectors 35 and 36 are both “0”,the logic circuit 37 directly connects the demultiplexer 14 to the multiplexer 20 .
FIG. 4A shows an embodiment of the vertical black band detector 35 . The output A from the median vertical low-pass filter 34 is applied the set input of a set-reset flip-flop 40 , while the horizontal synchronization H is applied to the reset (R) input. The horizontal synchronization signal H is also applied to a reset input of a pixel counter 41 which counts a pixel clock signal supplied by a pixel clock 42 locked to the horizontal synchronization signal H. The pixel counter 41 thereby counts the pixels in a line of the input video signal. Assuming a black band on the left edge of the picture, the signal A is initially “0”. At the time of a transition from “0” to “1”, the set-reset flip-flop 40 applies a signal to a first latch 43 which then captures the current pixel count value n1 in the pixel counter 41 . This count value n1 then is applied to a first input of a logic circuit 44 . The output from the pixel counter 41 is also applied to a second latch 45 which receives, as a latch signal, the output A having first been inverted in an inverter 46 . The second latch 47 captures the pixel count value at each occurrence of a “1” to “0” transition. However, since only the location of the last transition is desired, the output from this second latch 45 is applied to a third latch 47 which is latched by the horizontal synchronization signal H. The output n2 from this third latch 47 is applied to a second input of the logic circuit 44 . The logic circuit 44 determines when the count value n1 from the first latch 43 exceeds a given number, e.g., 20 , which would indicate that a left black band is present in a particular line, and determines when the count value n2 from the third latch 47 is smaller than a given number indicating the presence of a right black band. If both black bands are present in a given line, the logic circuit 44 outputs a “1” value. The output from the logic circuit 44 is applied to a counter 48 which is reset by the vertical synchronization signal V. The counter 48 counts the number of lines containing left and right black bands in a field. If this number exceeds a given number of lines, e.g., 260 lines, the threshold detector 48 applies a “1” value to its output, which is applied to the logic circuit 37 .
In a modification (not shown) of this embodiment, the output values from the first and third latches 43 and 47 may be stored and averaged over all of the lines in any given field to determine average values of n1 and n2 for the field. Then these average field values may be further averaged over several fields to determine, with a high degree of accuracy, the locations of the left and right black borders. This averaging, in conjunction with the median filters and threshold detection, will mitigate potential false occurrences of the left and right black borders.
FIG. 4B shows an embodiment of the horizontal black band detector 36 . In particular, The output A from the median vertical low-pass filter 34 is applied the set input of a set-reset flip-flop 40 ′, while the vertical synchronization signal V is applied to the reset (R) input. The vertical synchronization signal V is also applied to a reset input of a line counter 41 ′ which receives the horizontal synchronization signal H as a count input. The line counter 41 ′ thereby counts the lines in the input video signal. Assuming a black band at the top of the picture, the signal A is initially “ 0 ”. At the time of a transition from “0” to “1”, the set-reset flip-flop 40 ′ applies a signal to a first latch 43 ′ which then captures the current line count value in the line counter 41 . This count value is then applied to a first input of a logic circuit 50 . The output from the line counter 41 ′ is also applied to a second latch 45 ′ which receives, as a latch signal, the output A having first been inverted in an inverter 46 ′. The output from this second latch 45 ′ is applied to a third latch 47 ′ which is latched by the vertical synchronization signal V. The output from this third latch 47 ′ is then applied to a second input of the logic circuit 50 . The logic circuit 50 determines when the count value from the first latch 43 ′ exceeds a given number, e.g., 10 , which would indicate that a top black band is present in a particular field, and determines when the count value from the third latch 47 ′ is smaller than a given number, e.g., 255 , indicating the presence of a bottom black band. If both bands are present in a given field, the logic circuit 44 outputs a “1” value, which is applied to the logic circuit 37 .
Numerous alterations and modifications of the structure herein disclosed will present themselves to those skilled in the art. However, it is to be understood that the above described embodiment is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
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When viewing a 4:3 aspect ratio image on a widescreen display, disturbing black bands appear to the left and right of the displayed image. Similarly, when viewing a letterbox image on a 4:3 aspect ratio display, disturbing black bands appear above and below the displayed image. These black bands result in uneven ageing of the phosphors in the display screen. An apparatus is provided which detects these black bands and automatically expands the image in the appropriate direction such that these black bands are automatically eliminated.
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TECHNICAL FIELD
[0001] The present invention relates to a technology for displaying an image on an ultrasonic diagnostic apparatus and more particularly relates to a control technique for optimizing display of a tomographic image on an ultrasonic diagnostic apparatus.
BACKGROUND ART
[0002] An ultrasonic diagnostic apparatus is used to display a tomographic image representing an internal tissue of a subject's body. The tomographic image is generated based on an ultrasonic wave that has been sent out from an ultrasonic probe and then reflected from the internal tissue.
[0003] In this case, the tomographic image displayed will look incessantly different every time either the ultrasonic probe or the subject moves. For that reason, they say that some kind of processing for adjusting the image appearance by either increasing or decreasing the luminance of the tomographic image (which is so-called “optimization processing”) should be carried out.
[0004] Some methods for carrying out such optimization on an ultrasonic diagnostic apparatus by determining the best timing are proposed in Patent Documents Nos. 1 and 2, for example.
[0005] According to Patent Document No. 1, a variation in the pixel intensity histogram of a series of image frames is monitored. And if the feature quantity of that histogram has been stabilized for a certain period but if a significant variation has been sensed in the feature quantity of the pixel intensity histogram of the latest image frame, the computer decides that the ultrasonic probe has moved and gets the image optimized automatically.
[0006] On the other hand, according to Patent Document No. 2, ultrasonic images are sampled periodically and each of those ultrasonic image sampled is divided into a number of blocks. And if a difference in feature quantity between one block of the previous sampled image and its associated block of the current sampled image has exceeded a threshold value, then it is decided that some significant change has occurred and image optimization is carried out automatically.
CITATION LIST
Patent Literature
Patent Document No. 1: Japanese Patent Application Laid-Open Publication No. 2001-187057
Patent Document No. 2: Japanese Patent Application Laid-Open Publication No. 2007-98142
SUMMARY OF INVENTION
Technical Problem
[0007] According to the methods disclosed in Patent Documents Nos. 1 and 2, however, whenever any variation is sensed in the image, optimization is automatically done by the device. That is why the operator cannot know in advance exactly when optimization needs to be done but has no choice but to confirm that the optimization has already been done by sensing a significant change of the image. This means that the optimization could be done at an unwanted timing for him or her.
[0008] On top of that, even if the quality of the image that has been optimized is not up to the operator's expectations, he or she has to look at that tomographic image continuously, which is very inconvenient for him or her.
[0009] It is therefore an object of the present invention to allow the operator of an ultrasonic diagnostic apparatus to know the timing to optimize the image and also let him or her decide whether optimization needs to be done or not. Another object of the present invention is to allow the operator who has opted to optimize the image but who has sensed that the resultant optimized image is not to his or her expectations to change the current method of displaying the image.
Solution to Problem
[0010] An ultrasonic diagnostic apparatus according to the present invention includes: an ultrasonic probe for sending out an ultrasonic wave toward a vital tissue and receiving a reflected wave of the ultrasonic wave that has been reflected from the vital tissue; an image constructing section for constructing an image frame representing a tomographic image of the tissue based on the reflected wave; a display section for displaying the image frame thereon; and a processing section for analyzing an image feature quantity of the image frame and comparing the image feature quantity to a predetermined reference feature quantity. Based on a result of the comparison, the apparatus gives a notification that it is time to decide whether its operator wants the image quality of the image frame to be optimized now or not.
[0011] The processing section may adopt, as the predetermined reference feature quantity, a result of the analysis on the previous image frame displayed.
[0012] The ultrasonic diagnostic apparatus may further include an interface section for receiving an instruction from the operator. If after the apparatus gives the notification that it is time to decide whether the operator wants the image quality of the image frame to be optimized now or not, the interface section is instructed to control the image quality, the processing section may determine a parameter for setting the image quality to be a predetermined reference value based on a result of the analysis, and the image constructing section may reconstruct the image frame in accordance with the parameter.
[0013] The ultrasonic diagnostic apparatus may further include an interface section for receiving an instruction from the operator. If after the apparatus gives the notification that it is time to decide whether the operator wants the image quality of the image frame to be optimized now or not, the interface section is instructed not to control the image quality, the processing section may change the predetermined reference feature quantity.
[0014] If after the image constructing section has reconstructed the image frame in accordance with the parameter, the interface section is instructed not to control the image quality, the image constructing section may reconstruct the image frame without adopting the parameter determined.
[0015] If the interface section is instructed not to control the image quality, the processing section may replace the predetermined reference feature quantity with the image feature quantity of the image frame.
[0016] The processing section may analyze, as the image feature quantity, a luminance related feature quantity of each of multiple areas that have been defined in the image frame.
[0017] The interface section may be a piece of hardware that allows the user to instruct the apparatus to control the image quality.
[0018] The interface section may also be a piece of hardware that allows the user to instruct the apparatus not to control the image quality.
[0019] The display section may display a sign on its screen to give the notification that it is time to decide whether the operator wants the image quality of the image frame to be optimized now or not.
[0020] The ultrasonic diagnostic apparatus may further include a light-emitting device for giving the notification, based on a result of the comparison, the operator that it is time to decide whether the operator wants the image quality of the image frame to be optimized now or not.
ADVANTAGEOUS EFFECTS OF INVENTION
[0021] According to the present invention, the operator is notified that it is time to decide whether the operator wants the image quality of the image frame to be optimized now or not. That is to say, since the image quality is not changed suddenly without notice while the apparatus is used, the operator never feels unnaturalness. On top of that, by instructing the apparatus whether the image quality of the image frame needs to be optimized or not, the operator can decide by him- or herself whether the image quality should be controlled now or not.
[0022] Also, if the operator has instructed the apparatus not to control the image quality now, the reference feature quantity that was used when the operator was notified of that timing is changed. That is why the operator will be told the time to get the image quality optimized using a different reference after that.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 illustrates the appearance of an ultrasonic diagnostic apparatus 100 as a specific preferred embodiment of the present invention.
[0024] FIG. 2 is a block diagram illustrating an internal configuration for the ultrasonic diagnostic apparatus 100 of this preferred embodiment.
[0025] FIG. 3 is a flowchart showing the processing to get done by a processor 107 to determine whether it is the optimization timing or not.
[0026] FIG. 4 illustrates two sub-areas that overlap with each other.
[0027] FIG. 5 is a flowchart showing the procedure of the processing to get done after the operator has been notified.
DESCRIPTION OF EMBODIMENTS
[0028] Hereinafter, preferred embodiments of an ultrasonic diagnostic apparatus according to the present invention will be described with reference to the accompanying drawings.
[0029] FIG. 1 illustrates the appearance of an ultrasonic diagnostic apparatus 100 as a specific preferred embodiment of the present invention. Using an ultrasonic probe 101 , the ultrasonic diagnostic apparatus 100 displays a tomographic image of an internal body tissue as an image frame on a monitor 108 in real time. At that time, the user can control the image quality and other settings using various buttons on this ultrasonic diagnostic apparatus 100 (e.g., buttons 111 and 112 on a control panel).
[0030] FIG. 2 is a block diagram illustrating an internal configuration for the ultrasonic diagnostic apparatus 100 of this preferred embodiment.
[0031] The ultrasonic diagnostic apparatus 100 includes an ultrasonic probe 101 , an A/D converter 102 , a beam former 103 , a detecting section 104 , an image constructing section 105 , a frame memory section 106 , a processor 107 , a monitor 108 , a parameter storage section 109 , an optimization enter button 111 and an optimization cancel button 112 .
[0032] The ultrasonic probe 101 sends out and receives an ultrasonic beam as described above.
[0033] The A/D converter 102 converts the ultrasonic reflected wave received into a digital signal. The beam former 103 performs a delayed combination on the ultrasonic wave reflected wave that has been A/D converted. And the detecting section 104 carries out an envelope detection on an ultrasonic echo signal that has been subjected to the delay combination.
[0034] The image constructing section 105 subjects the ultrasonic echo signal detected to signal processing, thereby constructing a tomographic image frame representing the tissue.
[0035] The frame memory section 106 accumulates image frames of the tomographic image. What is accumulated in the frame memory section 106 may be nothing but tomographic image frames, which may be accumulated there either for a predetermined amount of time or in a predetermined number.
[0036] The processor 107 is a so-called central processing unit (CPU) and analyzes the tomographic image frames, thereby determining whether a currently presented image needs to be processed or not. For example, the processor 106 may analyze a series of tomographic image frames to detect any variation between them. And on sensing that the luminance value has decreased to a threshold value or less, the processor 107 may determine whether the luminance of the image should be increased or not.
[0037] The monitor 108 displays the tomographic image on it.
[0038] The parameter storage section 109 stores image quality control parameters and results of image analysis.
[0039] The optimization enter button 111 conveys the operator's image optimization enter instruction to the processor 107 . On the other hand, the optimization cancel button 112 conveys the operator's image optimization cancel instruction to the processor 107 .
[0040] This ultrasonic diagnostic apparatus 100 operates in the following manner.
[0041] An ultrasonic beam is sent out toward the subject by the ultrasonic probe 101 , reflected by his or her internal body tissue, and then received by the ultrasonic probe 101 . The A/D converter 102 converts an analog signal representing the ultrasonic reflected wave received into a digital signal. And the beam former 103 performs a delay combination on that ultrasonic reflected wave.
[0042] The detecting section 104 performs an envelope detection, thereby removing transmitted wave components (i.e., carrier components) from the received signal and outputting it as an ultrasonic echo signal to the image constructing section 105 .
[0043] The image constructing section 105 subjects the input ultrasonic echo signal to filtering, total gain application processing, TGC application processing, LGC application processing, frame gain application processing, scan conversion and other kinds of processing, thereby constructing an ultrasonic tomographic image frame, getting it stored in the frame memory section 106 and presenting it on the monitor 108 .
[0044] The processor 107 retrieves an image frame from the frame memory section 106 and analyzes the feature quantity of that image. As used herein, the “feature quantity” may refer to the luminance value of each of multiple regions that have been defined in the image or their standard deviation, for example.
[0045] Furthermore, the processor 107 compares the result of this analysis to the result of the previous analysis that has been obtained from the parameter storage section 109 , thereby determining whether or not there is any significant difference (such as a variation in luminance value, of which the magnitude exceeds a predetermined threshold value) between those two image frames. In this case, the “result of the previous analysis” refers to the result of the analysis that was performed on an image frame when the optimization enter button 111 was pressed by the operator last time.
[0046] And if there is any significant difference between them, the processor 107 decides that the time has come when the operator has to decide whether he or she wants the image quality to be controlled (or optimized) now or not (such a timing will be referred to herein as an “optimization timing”) and gives a notification to him or her or that by displaying a sign on the monitor. Instead of displaying such a sign on the monitor 108 , the operator may also be notified by blinking a light-emitting device such as an LED built in the optimization enter button 111 on the control panel or an LED (not shown) that is provided separately from the button.
[0047] It should be noted that the terms “control” and “optimization” herein have the same meaning. The “optimization processing” to be described later is a kind of processing for improving the image quality. That is why after the optimization processing has been done, it can be said that the image quality is higher than ever. For that reason, such a state in which the image quality has been improved to the maximum degree up to a certain point in time will be referred to herein as either an “optimized” state or a “controlled” state.
[0048] FIG. 3 shows the sequence of the processing to get done by the processor 107 to determine whether it is the optimization timing or not.
[0049] First of all, in Step 201 , the processor 107 divides a given image frame into a number of sub-areas, each having a width M and a height N that may have been set to be arbitrary values in advance. In this preferred embodiment, those sub-areas are defined to be completely separate ones that never overlap with each other. However, this is just an example and those sub-areas could overlap with each other. FIG. 4 illustrates two sub-areas that overlap with each other. The respective sub-areas may also be defined in this manner, too.
[0050] Next, in Step 202 , the processor 107 calculates the feature quantity of every sub-area. In this preferred embodiment, the standard deviation of the luminance values of all pixels in each sub-area is used as the feature quantity. As the feature quantity, not just the standard deviation but also some statistic such as an average, a median, or a coefficient of variation or the sum of power spectra of the images could be used as well.
[0051] Subsequently, in Step 203 , the processor 107 retrieves the previous sub-area feature quantity from the parameter storage section 109 , calculates the absolute value of the difference between the previous and current feature quantities on a sub-area basis and then calculates the sum of those differences, thereby obtaining a feature quantity difference Diff between the previous and current image frames.
[0052] Thereafter, in Step 204 , the processor 107 compares a preset threshold value Th to Diff. If the processor 107 finds Diff greater than the threshold value Th, then the processor 107 decides that it is time to update the image quality. Then, the process advances to Step 205 .
[0053] In Step 205 , the processor 107 notifies the operator that the optimization timing has come. In this processing step, the notification may be made either by displaying a sign on the monitor 108 or by blinking the light-emitting device just as described above.
[0054] Finally, in Step 206 , the processor 107 stores the feature quantity of each sub-area that has been calculated this time in the parameter storage section 109 so that the feature quantity can be used for analysis next time.
[0055] When the sign indicating that the optimization timing has come is displayed in Step 205 , the operator can get the image optimized by pressing the optimization enter button 111 .
[0056] Next, it will be described what processing will be performed after such a sign indicating that the optimization timing has come has been displayed.
[0057] FIG. 5 is a flowchart showing the procedure of the processing to get done after the operator has been notified.
[0058] First, in Step 301 , the processor 107 determines whether the operator has pressed the optimization enter button 111 or the optimization cancel button 112 . If the optimization enter button 111 has been pressed, the process advances to Step 302 . On the other hand, if the optimization cancel button 112 has been pressed, then the process advances to Step 307 .
[0059] If the optimization enter button 111 has been pressed, the processor 107 stores in Step 302 the current image quality control parameters in the parameter storage section 109 just before the settings are changed. And the processor 107 performs a series of processing steps 303 to, thereby calculating image quality control parameters to optimize the image and entering those parameters into the image constructing section 105 . Thereafter, in Step 306 , the image constructing section 105 reconstructs an image frame based on the image quality control parameters entered and then outputs the reconstructed image frame to the monitor 108 .
[0060] Specifically, those processing steps 303 through 306 are performed in the following manner.
[0061] First, the image quality control parameters for optimizing the image may be calculated by any of various methods. As an example, the processing of optimizing a TGC (time gain control) value will be described.
[0062] As used herein, the “TGC” means a control to be performed to reduce a variation in the lightness of an image within an image frame. Generally speaking, if an ultrasonic wave is used, its reflected wave will attenuate more steeply when reflected from a deeper region under the skin than when reflected from a shallower region under the skin. That is why an image representing that deeper region tends to darken. Thus, to overcome such a problem, the ultrasonic diagnostic apparatus 100 of this preferred embodiment classifies the depths under the skin 2 into seven levels, for example, and is ready to control the image lightness for each of those seven grades. As a result, the gain control can be done on a depth-by-depth basis so that an image frame can always be displayed with its lightness controlled according to the operator's preference, no matter whether the image frame represents a shallow region or a deep region under the skin. For instance, the image frame can always be displayed with its lightness kept constant at each and every depth. Or an image frame representing an internal body tissue that is located deep under the skin may be displayed with an increased lightness. And it is the TGC value that is used in such a depth-by-depth gain control.
[0063] The processing of optimizing the TGC value may be carried out as follows. Specifically, in Step 303 , the processor 107 calculates the average of luminance values for each depth level under the skin 2 in the image frame. Next, in Step 304 , the processor 107 determines a TGC value, which will be a predetermined reference value when multiplied with the average that has been calculated in the previous step, on a depth-by-depth basis again. In this preferred embodiment, the depths under the skin 2 are classified into seven levels and the image quality may be controlled adaptively according to the depth in question.
[0064] Then, in Step 305 , the processor 107 enters the TGC value thus determined as an image quality control parameter into the image constructing section 105 .
[0065] And in Step 306 , the image constructing section 105 reconstructs an image frame based on the image quality control parameters entered and then outputs the image frame thus obtained to the monitor 108 .
[0066] In some cases, even if the operator has pressed the optimization enter button 111 , he or she may press the optimization cancel button 112 after the optimization has been done.
[0067] In that case, the process advances to Step 307 , in which the processor 107 sees if any parameter is stored in the parameter storage section 109 . As can be seen from the processing step 302 , if the optimization enter button 111 has ever been pressed at least once, some parameter will be stored in the parameter storage section 109 .
[0068] But if the optimization enter button 111 has never been pressed yet, no parameters will be stored in the parameter storage section 109 . In that case, the processor 107 ends this processing. But if any parameter is stored in the parameter storage section 109 , then the process advances to Step 308 , in which the processor 107 replaces the threshold value Th with the difference Diff in feature quantity between the image frames. As a result, that Diff value will be used as the threshold value when it is determined next time whether or not it is time to make optimization. Then, the image frame on the monitor 108 does not change at all.
[0069] Next, in Step 309 , the processor 107 retrieves the TGC value just before the optimization from the parameter storage section 109 and enters it as an image quality control parameter into the image constructing section 105 . This means that the optimization processing that has been carried out once has been canceled. Then, in Step 310 , the image constructing section 105 reconstructs an image frame based on the image quality control parameter entered and then outputs the reconstructed image frame to the monitor 108 .
[0070] It should be noted that this processing step of entering the image quality control parameter just before the optimization into the image constructing section 105 is only an example. Anyway, as the user is not satisfied with the currently presented image, the way of displaying that image is preferably changed again. For that reason, instead of adopting the image quality control parameter just before the optimization, the types of image processing may be changed again and again until the user gets fully satisfied.
[0071] If the operator has pressed the optimization cancel button 112 , it means that he or she does not want to get the image quality optimized at that point in time. In other words, it indicates that the optimization standard presented at that point in time by the ultrasonic diagnostic apparatus 100 does not agree with the operator's. Thus, by changing the threshold value as described above, the threshold value can be even closer to the operator's optimization standard.
[0072] In the foregoing description of preferred embodiments, the frame storage section 106 is supposed to accumulate image frames of a tomographic image. However, image feature quantities, which are results of analysis on image frames, may be accumulated instead of the image frames themselves. As a result, the space left in the frame memory section 106 can saved.
[0073] Also, in the preferred embodiment described above, the user interface means that allows the operator to indicate whether or not he or she wants to get optimization done now is supposed to be the optimization enter button 111 and the optimization cancel button 112 , which are pieces of hardware. However, this is just an example. Alternatively, the monitor 108 may be implemented as a touchscreen panel that displays the buttons 111 and 112 thereon. In that case, portions of the touchscreen panel corresponding to the respective display locations of the optimization enter and cancel buttons 111 and 112 are used as the user interface means. Still alternatively, two dialog boxes that perform the same function as the buttons 111 and 112 may be displayed on the monitor 108 so as to be selectively entered with a mouse or a keyboard. In that case, the user interface means is the mouse or the keyboard.
[0074] The procedures of processing that have been described with reference to the flowchart shown in FIGS. 3 and 5 may be carried out as a computer program to be executed by the processor 107 . Such a computer program may be circulated on the market by being either stored on a storage medium such as a CD-ROM or downloaded over telecommunications lines such as the Internet. The processor 107 of the ultrasonic diagnostic apparatus 100 may be implemented as a general-purpose processor (i.e., a semiconductor integrated circuit) that can execute the computer program. Alternatively, the processor 107 may also be a dedicated processor in which such a computer program has been installed.
INDUSTRIAL APPLICABILITY
[0075] The ultrasonic diagnostic apparatus of the present invention can notify the user that it may be high time to optimize the image quality of a subject's tomographic image and prompts the user to decide by him- or herself whether or not the quality of the image presented should be optimized now. Consequently, according to the present invention, the user can check out the image after having its quality controlled according to his or her preference.
REFERENCE SIGNS LIST
[0000]
100 ultrasonic diagnostic apparatus
101 ultrasonic probe
102 A/D converter
103 beam former
104 detecting section
105 image constructing section
106 frame memory section
107 processor
108 monitor
109 parameter storage section
111 optimization enter button
112 optimization cancel button
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When a tomographic image is displayed, the operator of an ultrasonic diagnostic apparatus is allowed to know the timing to optimize the image quality and decide by him- or herself whether optimization needs to be done now or not.
The ultrasonic diagnostic apparatus includes: an ultrasonic probe for sending out an ultrasonic wave toward a vital tissue and receiving a reflected wave of the ultrasonic wave reflected from the tissue; an image constructing section for constructing an image frame representing a tomographic image of the tissue by calculating the magnitudes of displacements at multiple measuring sites on the tissue based on the reflected wave; a display section for displaying the image frame thereon; and a processing section for analyzing an image feature quantity of the image frame and comparing the image feature quantity to a predetermined reference feature quantity. Based on a result of the comparison, the apparatus gives a notification that it is time to decide whether its operator wants the image quality of the image frame to be optimized now or not.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Stage of PCT Application No. PCT/EP2010/064566, filed Sep. 20, 2010, which claims priority benefits to German Patent Application No. 10 2009 046 632.0, filed Nov. 11, 2009.
BACKGROUND
The invention relates to shower heads with a rigid housing.
Shower heads with a jet form which differs from the conventional water jet of round cross section are known, for example, from WO 02/28540 A1. The shower head illustrated in FIG. 3 of said document, also referred to as a dual shower attachment, has a length of approximately 30 cm and a width of approximately 6 cm. The height is approximately 2 cm, thus resulting in a rigid flat housing with inner water flow channels. A shower plate is arranged at each of the two ends of the housing, thus resulting in a dual shower with two individual jets spaced apart from one another. This measure achieves better distribution of the water over the body of the person who is taking a shower. However, the greater number of nozzles in comparison with conventional shower heads reduces the intensity of the exiting water jet.
A shower head which allows good water distribution and an intense water jet is known from DE 202 12 727 U1. The shower head comprises two shower-head parts which can be pivoted in relation to one another. Each shower-head part has a set of nozzles. The first set of nozzles is oriented downward when the shower-head parts have been pivoted into a position in which they are adjacent to one another. In this pivoting position, a circular water jet exits from this shower head. The second set of nozzles is located on the elongate portion of the two pivotable shower-head parts. A water curtain exits through these nozzles when the shower-head parts have been pivoted apart from one another, so as to extend in the horizontal direction. The water curtain follows a curved line and may be located in the shoulder region of the person who is taking a shower, and therefore the person who is taking a shower is sprayed uniformly with water without the exiting water making his hair wet. The articulation for the shower-head parts is designed as a rotary valve, which directs the water, in the first pivoting position, to the first-mentioned set of nozzles and, in the second pivoting position, to the second-mentioned set of nozzles. This shower head is very complex and costly to produce.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to develop a shower head which is simple and cost-effective to produce and generates, on the one hand, a concentrated water jet and, on the other hand, an extensive water curtain.
This object is achieved according to the invention by a shower head with a rigid housing, which has a connection for a water line and at least one water flow channel, which can be connected to the water line and opens out into nozzles, which are arranged on that side of the housing which is oriented downward during use and have water jets exiting through them, wherein the housing has an elongate flat shape, is developed in that the nozzles are distributed essentially over the entire length of the housing, and the shower head is assigned a manually actuable shut-off device, by means of which it is possible to interrupt the flow of water to some of the nozzles.
When the nozzles are fully open, a gentle water curtain is distributed, not just at certain points, but over the entire underside of the shower head, and sprays onto the shoulders of the person who is taking a shower. If the shower head is arranged a little way above the shoulders, the hair does not become wet from the exiting water. The water flows only onto the shoulders and the back region.
If, in contrast, some of the nozzles are shut off by means of the manual shut-off device, the pressure and the quantity of the water flowing out increases in those nozzles which remain open. This gives rise to a more intense water jet, referred to hereinbelow as rinsing jet. The rinsing jet is harder and more concentrated than the water curtain, when the nozzles are fully open, and is thus highly suitable for rinsing the hair or for rinsing off soap.
The shower head performs the same tasks as the shower head which is known from DE 202 12 727 U1. However—apart from the shut-off device for the lateral nozzles—it does not have any movable elements, in particular any pivotable shower-head parts. The shower head can be produced as a simple plastics-material or metal housing made of two interconnected shells. The water channel which leads from the connection for the water line to the nozzles is formed here by the cavity within the housing. Such a shower head is simple and cost-effective to produce.
In practice, the nozzles may be arranged along a curved center line. In particular, the elongate housing itself, as seen from beneath, may have a curved center line. The elongate housing extends, during use, essentially parallel to the surface of the user's back, and thus usually parallel to the shower wall located behind the user. The curvature of the elongate housing, as seen by the person who is taking a shower, is concave. This means that the ends of the elongate housing are curved in the direction of the user. In this way, the elongate housing extends essentially over a portion of a ring. The user thus stands beneath the elongate housing such that his neck is located in the region of the center of the housing, wherein the two ends of the housing extend over the user's shoulders. A water curtain then exits from the housing along a circle portion and sprays, in the center, onto the user's neck and back and, at the lateral ends, onto the user's shoulders.
It is preferable for the nozzles which are remote from the center of the housing to be designed in a closable mariner and for the central nozzles to be designed such that they cannot be closed. In other words, the shut-off device, in a first switching position, releases the flow of water to all the nozzles and, in a second switching position, interrupts the flow of water to the nozzles which are remote from the center of the housing. When the lateral nozzles are closed, the rinsing jet then exits symmetrically in relation to the center of the housing. This is advantageous, in particular, in embodiments in which the fastening means of the housing is arranged in the center. Since the rinsing jet exits symmetrically in relation to the housing center, it does not generate any torque around the fastening means and cannot rotate the housing. Moreover, the user's head is located centrally between his shoulders, and therefore, when switching over to the rinsing jet by shutting off the lateral nozzles of the shower head, the user need not change his position if he wishes to wash his haft and, for this purpose, directs the rinsing jet onto his head.
In practice, the shower head may have at least two flow cross sections. The water flows through a first flow cross section to the nozzles which are arranged in the center of the housing. The water flows through a second flow cross section to the nozzles which are remote from the center of the housing. The shut-off device, in the second switching position, closes the second flow cross section.
In the first switching position, the shut-off device can partially close the first flow cross section and release the second flow cross section. The water is directed to the lateral regions of the shower head, in practice, through smaller flow cross sections than it is directed to the central region of the shower head. A partial closure of the first flow cross section throttles the flow to the central nozzles somewhat, so as to produce a very uniform and homogenous shower jet over the entire width of the shower head.
In practice, the shut-off device may have a contact slide which can be displaced counter to a return spring and, in the case of the contact slide being subjected to a first push, remains in a first latching position and, in the case of the contact slide being subjected to a second push, remains in a second latching position, wherein the contact slide, in its first latching position, moves the shut-off device into the first switching position thereof and, in its second latching position, moves the shut-off device into the second switching position thereof. The contact slide, in a manner similar to the actuating knob of a ballpoint pen, can latch into two positions via a latching mechanism. Simply by pushing on the contact slide, it is possible to switch over between the two switching positions of the shut-off device. This is simple and is also possible with wet fingers.
The connection for the water line may likewise be arranged in the center of the shower head. In a practical embodiment, the connection for the water line is a connector provided with an external thread, wherein the external thread serves, at the same time, as fastening means of the housing.
In practice, the number of nozzles which are arranged in the center of the housing may be greater, per unit of surface area, than the number of nozzles which are remote from the center of the housing. When soap or shampoo is being showered off, the higher number of nozzles in the center of the shower head generates a particularly intense water jet.
In a practical embodiment, the underside of the shower head has a plurality of diffusers which are arranged along the center line of the housing and each have a plurality of through holes which form the nozzles. The diffusers are produced as standard components for conventional shower heads. They can be accommodated in the underside of the housing of the shower head according to the invention and thus form a plurality of, for example five, water jets located one beside the other.
The diffusers preferably each generate a conically diverging water jet made up of a plurality of individual jets. Each diffuser on the underside of the housing may be designed convexly for this purpose, wherein one nozzle in the center generates a jet which runs essentially perpendicularly to the plane of the housing and the other nozzles, as the distance thereof from the center of the diffuser increases, are inclined to an increasing extent in relation to the vertical onto the underside of the housing. Consequently, the outer nozzles emit the water in jets obliquely outward. The result, for each diffuser, is a water jet which is fanned out conically. For example, five diffusers may be arranged on the underside of the housing along the curved center line of the housing. At a short distance from the underside of the housing, e.g. at a distance of 10 to 20 cm, the jets of adjacent diffusers run into one another and form a closed water curtain.
In order to shut off the outer nozzles, a simple slide can shut off the water flow channel which leads to the outer nozzles. In the region of the circumference of a central diffuser, an annular shut-off slide may be arranged in a rotatable manner in the shower head. In a first rotary position, the shut-off slide releases a through-passage to the outwardly leading water flow channels. In a second rotary position, the shut-off slide shuts off these water flow channels and no water exits from the outer diffusers. In this second position, the shower head functions like a simple hand-held shower head, in the case of which the water exits through a single diffuser in the center of the shower head.
The slide may be manually operable in practice. For example, movable operating elements which are coupled to the slide may project out of the housing of the shower head. Depending on the desired functioning mode, the user can displace the operating elements into a first end position, in which the supply flow to the outer nozzles is released, or into a second end position, which is located opposite the first end position and in which the supply flow to the outer nozzles is shut off. It is also possible for the slide to be formed onto the periphery of the central diffuser. The central diffuser may have a periphery which extends along a cylinder surface, projects into the housing and has two windows located opposite one another. These windows, in a first rotary position, are aligned with the outwardly leading water flow channels. In this rotary position, water flows from the connection to all the diffusers. In a second rotary position, the outwardly leading water flow channels are blocked by the cylindrical peripheries, and the water exits only through the central diffuser. In order for the periphery of the central diffuser to be rotated, the central diffuser is fastened in a rotatable manner on the housing.
The housing may be a very flat design in practice. It is also possible for a connector, which is located on the housing and forms the connection for the water line and possibly the fastening means of the housing, to be inclined only to a very slight extent in relation to the plane of the housing. This means that the housing lends itself well to stacking and can be stored in a space-saving manner. It is also possible, however, for the shower head with flat housing to be placed in a space-saving manner in a suitcase or a bag and thus to be used, for example, for traveling.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention will be explained hereinbelow with reference to the attached drawings.
FIG. 1 shows a side view of the shower head during use.
FIG. 2 shows a plan view of the shower head during use.
FIG. 3 shows a side view of the shower head during rinsing operation.
FIG. 4 shows a bottom view of the shower head.
FIG. 5 shows a side view of the shower head.
FIG. 6 shows a plan view of the shower head.
FIG. 7 shows a front view of the shower head.
FIG. 8 shows an illustration which has been sectioned along section line VIII-VIII in FIG. 6 and in which the shut-off device is in the rinsing position.
FIG. 9 shows an illustration of the shower head in section along section line IX-IX in FIG. 8 .
FIG. 10 shows an illustration of the shower head in the rinsing position and in section along section line X-X in FIG. 8 .
FIG. 11 shows an illustration, corresponding to FIG. 8 , of the shower head in the showering position.
FIG. 12 shows an illustration of the shower head from FIG. 11 in section along section line XII-XII.
FIG. 13 shows a three-dimensional view of a further embodiment of a shower head.
FIG. 14 shows a bottom view of the shower head from FIG. 13 .
FIG. 15 shows a sectional plan view of the shower head from FIG. 13 with the shut-off device open.
FIG. 16 shows an illustration, corresponding to FIG. 15 , of the shower head with the shut-off device closed,
FIG. 17 shows a sectional side view of the shower head from FIG. 16 .
DETAILED DESCRIPTION
As can be seen, in particular, in FIG. 4 , the shower head comprises an elongate housing 1 , of which the center line extends along a circle. A tubular connector 2 is arranged on the housing 1 and has its free end provided with an external thread 3 . The external thread 3 serves for fastening on a water line 4 (see FIGS. 1 to 3 ). The hollow connector 2 directs the water from the water line 4 to the interior of the housing 1 . The housing 1 can expediently be produced by plastics injection molding.
Five diffusers 5 are arranged on the underside of the housing 1 , these having a multiplicity of through holes which form nozzles 6 for the exit of water. As can be seen, in particular, in FIG. 5 , the diffusers 5 are of convex design, and therefore they generate a conical water jet 7 . FIG. 4 shows that the diffusers 5 extend essentially over the entire length of the elongate, curved housing 1 . The diameter of the diffusers 5 is only slightly smaller than the width of the housing 1 . If all the diffusers 5 are active, the shower head according to the invention generates a water curtain which extends over the entire surface area of the curved housing 1 . On account of the conical water jet of each diffuser, the water jets of the individual diffusers 5 come together at a small distance from the underside of the shower head, a closed water curtain being formed as a result. This can be seen, for example, in FIGS. 1 and 2 . The person 8 who is taking a shower arranges the shower head according to the invention preferably in the region of his neck, and therefore the water curtain sprays onto the neck and the shoulders of the person 8 who is taking a shower ( FIGS. 1 and 2 ), but his hair remains dry.
A manually actuable lever 9 , which forms part of a shut-off device, is arranged on the upper side of the shower head. The shut-off device has a bell 10 , which is fixed to the lever 9 and is accommodated in a rotatable manner in the housing 1 . The bell 10 forms an annular shut-off slide for the water flowing to the lateral diffusers 5 . A first switching position releases the flow of water to all the nozzles. This switching position is illustrated in FIGS. 11 and 12 . The bell 10 has windows 11 , which are located opposite one another and, in this first switching position, are aligned with through-channels 12 which are arranged in that wall of the housing 1 which encloses the bell 10 . Water flowing into the bell can flow into the lateral regions of the housing 1 through the windows 11 and through the through-channels 12 and can exit from all the diffusers 5 over the entire length of the shower head.
The resulting water curtain is illustrated in FIGS. 1 and 2 .
The water flowing in flows through an inflow opening 13 in the upper region of the bell 10 . The inflow opening 13 extends over an angular region of approximately 90° and, in any desired rotary position of the bell 10 between two switching positions which are offset through 90° in relation to one another, releases the through-passage for the water from the interior of the connector 2 into the interior of the bell 10 .
The second rotary position of the bell 10 is illustrated in FIGS. 8 and 10 . Here, the windows 11 have been rotated through 90 ° in relation to the through-channels 12 . The wall of the bell 10 blocks the throughflow of the water into the lateral regions of the housing 1 . As can be seen in FIG. 8 , in this rotary position of the bell 10 , the water can exit exclusively through the central diffuser 5 , which is located directly beneath the bell 10 . In this rotary position of the bell 10 , the central diffuser 5 is subjected to the total pressure of the water in the water line 4 . A rinsing jet, which can be seen in FIG. 3 , exits from the central diffuser 5 . This rinsing jet is more intense than the water curtain, which is produced when the water exits through all the diffusers 5 .
It should be noted that the shut-off device, which is illustrated in particular in FIGS. 8 to 12 , merely constitutes an example. Any other desired embodiments of such shut-off devices are conceivable. For example, it is possible to use slides which shut off through openings for water which flows to the lateral diffusers. It is likewise possible for the bell 10 to be produced in one piece with the diffuser 5 , and therefore the lateral diffusers can be shut off simply by virtue of the diffuser 5 being rotated. Any other desired shut-off mechanisms on the housing 1 , or in the vicinity thereof, can be used for shutting off the inflow of water into the lateral diffusers. The shut-off devices may advantageously be designed such that only one grip is necessary to switch over between the two switching positions of the shut-off device.
FIGS. 13 to 17 show a further embodiment of a shower head according to the invention.
The housing 1 ′ here is produced by plastics injection molding. It comprises a plurality of housing shells, which are glued or screwed to one another. The lower shell of the housing 1 ′ has the nozzles 6 ′. These can be introduced into the hard housing shell by 2-component injection molding using rubbery plastics material.
It can be seen in particular in FIG. 14 that the nozzles 6 ′ in the lateral wings of the housing, that is to say the nozzles 6 ′ which are remote from the center of the housing 1 ′, are spaced apart from one another by a greater distance than the nozzles 6 ′ in the center of housing. The number of nozzles arranged per square centimeter in the center of the housing is almost double that in the lateral portions (wings) of the housing 1 ′. This means that the water jet which exits in the center when the housing wings are shut off is very intense and can reliably rinse off soap or shampoo.
In the embodiment of FIGS. 13 to 17 , the flow of water is switched over by a contact slide 14 . The contact slide 14 can be pushed into the housing 1 ′, in the direction of the connector 2 ′, in the manner of a pushbutton. As FIGS. 15 and 16 show, the contact slide 14 is connected to a shut-off body 20 via a coupling element 22 . Opposite the contact slide 14 , a return spring 21 acts against the shut-off body 20 . The return spring 21 pushes the shut-off body in the direction of the contact slide 14 . A latching mechanism (not illustrated), which acts in a manner similar to the latching mechanism of a ballpoint pen, defines two latching positions of the contact slide 14 and thus of the shut-off body 20 . The first latching position is shown in FIG. 15 . Here, the contact slide 14 has been pushed into the housing 1 ′ and the shut-off body 20 allows the flow of water to all the nozzles 6 ′ of the shower head. FIG. 15 shows that the shut-off body 20 has two lateral arms, each with a sealing ring 15 and a sealing stub 16 at the end thereof. A first flow cross section 17 , which leads to the central nozzles 6 ′, is open in the two latching positions of the shut-off body 20 . A second flow cross section 18 , which leads to the lateral nozzles 6 ′, is fully open in the first switching position ( FIG. 15 ) and fully closed, by the sealing ring 15 , in the second switching position ( FIG. 16 ). Consequently, in the second switching position ( FIG. 16 ), the sealing ring 15 shuts off the flow of water to the lateral regions of the housing 1 ′.
It can be seen in FIGS. 15 and 16 that the flow of water to the lateral regions of the housing takes place, on the one hand, around elongate arms of the pressure-exerting body 20 and, on the other hand, through a relatively thin tube 19 . This results in the flow of water to the lateral regions of the housing 1 ′ being throttled. In order that, when the second flow cross sections 18 are open, the flow to the central nozzles 6 ′ is not very much more intense than the flow to the lateral nozzles, the sealing stubs 16 , in the first switching position, project into the first flow cross section and partially close the latter. As a result, the open surface area of the first flow cross section 17 is reduced and the flow through this flow cross section 17 is throttled. This gives rise to an essentially uniform flow through the nozzles 6 ′ in the lateral regions of the housing 1 ′ and the nozzles 6 ′ in the center of the housing 1 ′.
The pushbutton-like actuation of the contact slide 14 renders the operation of this shut-off device extremely simple, and therefore a person who is taking a shower can operate the shut-off device reliably with wet hands, even if his eyes are closed.
LIST OF DESIGNATIONS
1 , 1 ′ housing
2 , 2 ′ connector
3 external thread
4 water line
5 diffuser
6 , 6 ′ nozzle
7 water jet
8 person
9 manually actuable lever
10 bell
11 window
12 through-channel
13 inflow opening
14 contact slide
15 sealing ring
16 sealing stub
17 first flow cross section
18 second flow cross section
19 side channel
20 shut-off body
21 return spring
22 coupling element
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The invention relates to a shower head having a rigid housing ( 1 ), having a connection for a water line ( 4 ) and at least one water transport channel which can be connected to the water line ( 4 ) and which ends in nozzles which are arranged on the side of the housing ( 1 ) pointing down when in use and through which water streams emerge, wherein the housing ( 1 ) has an elongated, flat shape. The aim of the invention is to develop a simple and cost-effectively produced shower head which generates a concentrated water stream and also generates a broad water curtain. Said aim is achieved in that the nozzles are substantially distributed over the entire length of the housing ( 1 ) and a manually activated shut-off device is combined with the shower head by means of which the water stream to one part of the nozzle ( 6 ) can be interrupted.
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This application is a continuation, of application Ser. No. 565,808, filed 12/27/83, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to ultraviolet water purification systems and is directed more particularly to an improved monitoring port for facilitating measurements of the intensity of ultraviolet radiation at selectable positions within the purification system.
In order to purify water which is contaminated by bacteria, it is a common practice to direct the water through a purification system which exposes the water to ultraviolet (UV) radiation. Because UV radiation is able to kill bacteria, the water emerging from such a purification system has a greatly reduced live bacteria content and can often be safely used without further treatment.
Because the effectiveness of UV purification systems is dependent upon the ability of a UV lamp or lamps to apply more than a predetermined intensity of UV radiation to the water for more than a predetermined time, such systems are usually provided with UV monitoring arrangements for measuring the UV output of the lamps. Such monitoring arrangements include UV sensitive electronic devices which are coupled to respective UV lamps through respective UV transparent monitoring ports or windows that penetrate the external walls of the purification system. One such monitoring arrangement is described in U.S. Pat. No. 3,471,693, which issued in the name of L. P. Veloz on Oct. 7, 1969.
In some UV purification systems, the UV monitoring arrangement is arranged to measure the level of UV radiation which exists near the surface of a UV lamp. Monitoring arrangements of this type have monitoring ports with inlets that are located at or near the outer surface of the lamp itself, or near the outer surface of a quartz tube or envelope that surrounds the lamp and protects the same from exposure to the water to be purified. In other UV purification systems, the monitoring arrangement has a monitoring port with an inlet that is located in the fluid retaining wall of the system. In systems of the latter type, radiation is incident on the monitoring arrangement only after passing through the water to be purified.
Both of the above types of monitoring arrangements have deficiencies which limit the usefulness of the output information provided thereby. The problem with a monitoring arrangement which has an inlet that is close to the surface of a lamp is that the UV sensitive electronic device is unable to determine whether the UV radiation intensity at points more distant from the surface of the lamp is adequate to assure complete purification. The problem with a monitoring arrangement which has an inlet that is located at the fluid retaining wall of the system is that it allows a user to take measurements only through a fixed depth of liquid. As a result, such an arrangement prevents a user from measuring the UV radiation intensity at other distances from the surface of the UV lamp. A UV purification system which has UV monitoring arrangements of both types is shown in U.S. Pat. No. 4,336,223, which issued on June 22, 1982 in the name of L. Hillman.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an improved monitoring port which allows the intensity of UV radiation to be measured at any desired point between the outer surface of the UV lamp (or its protective envelope) and the fluid retaining wall of the purification system. Generally speaking, the monitoring port of the invention includes an elongated UV radiation transmitting member, which serves as a light pipe, and an improved sealing arrangement which allows the position of the transmitting member to be changed, while the purification system is operating, without allowing water to leak therefrom. The monitoring port of the invention also includes a locking arrangement which locks the transmitting member in place after it has been moved to the desired position. Together, these features allow a user to perform a series of measurements which give the UV radiation intensity in the system as a function of the distance from the UV lamp, the UV transparency of the water being purified and the quantity of UV blocking deposits which have accumulated on the internal surfaces of the system.
DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the present invention will be apparent from the following description and drawings in which:
FIG. 1 is a partial cross-sectional view of a UV purification system which includes the preferred embodiment of the monitoring port of the invention, and
FIG. 2 is an external view of an alternative embodiment of the monitoring port of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a partial cross-sectional view of one part of a flow-through UV purification system of a type that is suitable for use with the monitoring port of the present invention. This purification system includes a fluid-retaining vessel 10, which may comprise a tube or pipe composed of a corrosion-resistant material such as stainless steel or plastic. Centered within tube 10 are a UV lamp 12 and its tubular protective envelope or jacket 14 which is composed of a UV transparent material such as fused quartz. The ends of envelope 14 are sealed to tube 10 by sealing structures (not shown) in order to protect the fragile walls of UV lamp 12 from contact with the water within tube 10. Together, the outer surface of envelope 14 and the inner surface of tube 10 define a flow space within which the water that flows through the purification system is exposed to intense UV radiation from lamp 12.
In order to assure a continuous flow of water through the purification system, tube 10 is provided with an inlet and an outlet (not shown) which are preferably located in the sides thereof. The latter location allows the ends of tube 10 to be occupied by the above-mentioned sealing structures and by the electrical leads of lamp 12. Because sealing structures that are suitable for use in the purification system of FIG. 1 are well known to those skilled in the art, they will not be described in detail herein.
To the end that a user may measure the UV radiation intensity at any selected point between the outer surface of quartz envelope 14 and the inner surface of tube 10, there is provided the monitoring port 20 of the present invention. In the embodiment of FIG. 1, monitoring port 20 includes a UV transparent radiation transmitting member 22 which preferably comprises a rod of fused quartz. In operation, transmitting member 22 serves as a light pipe to receive UV radiation at inlet end 22a thereof and to output that radiation at outlet end 22b thereof. Because of the constancy and low magnitude of the losses that are associated with the absorption of UV radiation by the material of rod 22 and the internal reflection of UV radiation from the inner surface thereof, a fixed portion of the UV radiation that enters inlet end 22a of member 22 will emerge from outlet end 22b thereof. In other words, the UV radiation intensity at outlet 22b of member 22 will be a substantially constant fraction of the intensity of UV radiation at inlet 22a thereof. As a result, a UV sensitive measuring device, such as a photodiode or photocell, that is located at outlet 22b of member 22 will produce an output signal that is proportional to the output signal which would be produced if the device were located at inlet 22a of member 22.
To the end that inlet 22a of transmitting member 22 may be moved to any desired distance from the outer surface of envelope 12, monitoring port 20 includes a mounting member 24, a sealing member 26, and first and second locking members 28 and 30. In the embodiment of FIG. 1, mounting member 24 is permanently attached to tube 10 by a suitable water-tight weld 32. Passing through member 24 is a central hole 34 which is large enough to permit the free inward and outward movement of transmitting member 22. The leakage of the water through hole 34 is prevented by sealing member 26, which preferably comprises an O-ring that is positioned in a groove within mounting member 24. It will therefore be seen that inlet 22a of transmitting member 22 may be moved to any desired distance from the outer surface of envelope 14 without permitting fluid to leak from tube 10.
Once inlet end 22a of member 22 is located the desired distance from the envelope 14, it may be locked in that position by the locking assembly including locking members 28 and 30. To the end that this may be accomplished, first locking member 28 is preferably composed of an elastomeric material, such as rubber or soft plastic which, when compressed, will firmly grip and hold member 22. In addition, second locking member 30, which is preferably composed of metal, is provided with threads 30a which are adapted to engage the matching threads of mounting member 24. These threads assure that, as locking member 30 is tightened on mounting member 24, locking member 28 is compressed against member 22 and locks the same in place. This compressing action is made particularly effective by providing the outer surface of member 28 and the inner surface of member 30 with matching tapers.
When transmitting member 22 is to be moved to a new position, the user of the purification system need only loosen locking member 30, push or pull transmitting member 22 to the desired new position, and then retighten locking member 30. Significantly, this repositioning may be accomplished without draining the purification system, and without causing water to leak therefrom. This is because O-ring 26 seal maintains a liquid-tight seal between members 22 and 24 for all positions of member 22. Thus, monitoring port 20 makes it possible to measure the UV radiation intensity at any desired point in the layer of liquid between the outer surface of envelope 14 and the inner surface of the tube 12, while the purification system is in operation.
In order to make it easy to locate inlet 22a of member 22 at any desired distance from envelope 14, a positioning aid such as an indicator may be used. In the embodiment of FIG. 1 this positioning aid comprises a position indicator 40 including a pointer 42 that is attached to member 22 and a scale 44 that is attached to the wall of vessel 10. Alternatively, the positioning aid may include a stop and projection structure which define discrete predetermined positions for member 22. Such a structure might, for example, include a stop member which is attached to vessel 10 and which includes a series of steps that correspond to desired stop positions, and a projection which is attached to member 22 and which is adapted to engage the steps of the stop member. When being used with the latter type of positioning aid, member 22 may be rotated out of contact with the stop member to facilitate changes in its position. Other types of position indicating or measuring arrangements will be apparent to those skilled in the art.
If the outer wall of transmitting member 22 is not provided with a coating of a material which is opaque to UV radiation, some UV radiation may be able to enter member 22 through side surface 22c thereof. Since the UV rays that enter member 22 through side surface 22c originate at points that are more distant from envelope 12 than those that enter through end surface 22a, such rays tend to complicate the interpretation of the UV radiation intensity readings that are taken at output 22b of member 22. Accordingly, in those purification systems in which the UV rays that enter member 22 through side surface 22c produce objectionable errors, the side surface 22c of member 22 should be provided with a coating which is opaque to UV radiation. The effect of such a coating may also be produced by replacing quartz rod 22 with a length of property terminated stiff fiber optic cable which is provided with a UV opaque insulating sheath.
Referring to FIG. 2, there is shown an external view of an alternative embodiment of the monitoring port of the invention. Monitoring port 20' of FIG. 2 is generally similar to monitoring port 20 of FIG. 1, like functioning parts being similarly numbered. Monitoring port 20' of FIG. 2 differs from port 20 of FIG. 1, however, in that its mounting member comprises a T-shaped pipe fitting 24' which is located in fluidic series with tube 10 of the purification system. Because of the functional similarity between the embodiment of FIGS. 1 and 2, the embodiment of FIG. 2 will not be described in detail herein.
In view of the foregoing, it will be seen that a monitoring port constructed in accordance with the present invention provides a number of advantages over previously used UV monitoring ports. Firstly, the monitoring port of the invention makes it possible to measure the effective UV radiation intensity at any desired distance from the UV lamp with which it is used. Secondly, the monitoring port of the invention makes it possible to determine the intensity profile of the UV radiation within the purification system and allows calculation of the absorption coefficient of the water being purified.. Finally, the monitoring port of the invention provides these results while the system is operating, without allowing water to leak out of the purification system.
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A monitoring port for use in measuring the intensity of the ultraviolet radiation within an ultraviolet water purification system. A UV transparent transmitting member is sealably mounted for inward, outward, and rotational movement movement with respect to a UV lamp. A locking arrangement including a tapered elastomeric gripping member and a tapered metal tightening member assures that the transmitting member may be locked in place at any desired distance from the surface of the UV lamp. A positioning arrangement such as distance indicator or a series of positions stops, may be employed to facilitate the positioning of the transmitting member at any of the selected distances.
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FIELD OF THE INVENTION
The invention relates to a sieve screen, comprising:
a plurality of screening plates, spaced from each other and establishing a screening surface which is provided with screening slots and on top of which can be placed the material to be screened rotatable shafts below the screening surface, and blades which project from the shafts and extend through the screening slots to above the screening surface.
BACKGROUND
Such a sieve screen is known from the Applicant's German utility model DE 202006001257 U1. This prior known piece of equipment provides a good separating capability and high capacity with respect to other sieve screens available in the marketplace. Also, the screen obstruction problems are avoided even with wet materials and, if necessary, even small fraction sizes can be screened. However, this prior known sieve screen involves a drawback that each sieve screen bucket is only applicable to one fraction size. This drawback is also present in the sieve screen bucket disclosed in the Applicant's patent application FI 20135247.
SUMMARY OF THE INVENTION
It is an object of the invention to obviate this drawback and to provide a sieve screen of the above-mentioned type, which can be assembled or modified easily and quickly for a capability of screening various fraction sizes while using similar or the same screening plates and blades.
This object is attained in the invention with a sieve screen presented in the appended claim 1 . The dependent claims present preferred embodiments of the invention.
A sieve screen of the invention can be placed in a utility machine-operated screen bucket or the sieve screen can also be placed in a screening station movable with its own actuator.
In a sieve screen of the invention, the screening surface is not moving as opposed to generally known screening methods. The screening surface consists of stationary screening plates and the movement of a material to be screened over the sieve screen or across the sieve screen is achieved with blades rotated by shafts present below the screening surface and extending through the screening surface. This design enables the construction of a robust screening surface, whereby pre-screening prior to fine screening is not absolutely necessary. The screening operation can also be activated with the material already on top of the sieve screen, because the driving force required by the blades is hardly dependent on the amount of material on top of the sieve screen but solely on the type of material. Hence, this also enables the screening on a batch principle, such as the use as a bucket machine attachment, wherein material is collected into a bucket and the screening is not started until thereafter. The sieve screen also enables a more efficient use of the screening surface and thereby a higher capacity per screening area than methods based solely on gravity, since the fine material is forced by means of rotating blades rapidly through the sieve screen, whereby the throughput time can be influenced by the speed of the blades and the power to be applied. This makes it possible to manufacture high capacity compact sieve screens.
BRIEF DESCRIPTION OF THE DRAWINGS
One exemplary embodiment of the invention will now be described more closely with reference to the accompanying drawings, in which
FIG. 1 shows a sieve screen bucket of the prior art in cross-section when positioned in an excavator bucket 1 .
FIG. 2 shows, in an assembly drawing, a sieve screen for the sieve screen bucket of FIG. 1 when removed from the bucket. A sieve screen cartridge unit is capable of being installed in the bucket across an open rear side of the bucket;
FIG. 3 shows a shaft with its blades for the sieve screen of the invention, the blades being sized in terms of thickness to match a minimum fraction size
FIG. 4 shows a section taken from FIG. 3 along a line A-A
FIG. 5 a shows the shaft with its blades according to FIGS. 3 and 4 with the blades set in a position matching the minimum fraction size
FIGS. 5 b and 5 c show the same shaft as FIG. 5 a , but the blades have been displaced and grouped in a direction of the shaft so as to have two blades each time adjacent to each other without an intervening gap
FIG. 6 shows the same shaft as FIG. 5 a , but the blades have been displaced and grouped in a direction of the shaft so as to have three blades each time adjacent to each other without an intervening gap; and
FIG. 7 shows, in a perspective view, a portion of the sieve screen of the invention when placed in a sieve screen bucket. The sieve screen features shafts 4 provided with an arrangement of blades 5 according to FIGS. 5 b and 5 c , whereby the screening plates are respectively set in pairs without an intervening screening slot, the gaps between the screening plate sets matching the thickness of the blade sets.
DETAILED DESCRIPTION
First described is the prior art as shown in FIGS. 1 and 2 , which provides a basis for the present invention and which makes up an evolution of the present invention. The sieve screen comprises a screening surface 2 provided with slots, on top of which can be placed a material to be screened. Screening coarseness is determined by the width of the slots. The screening surface is constructed in such a way that the ends of separate screening plates 3 are fixed between flat mounting bars 6 and 12 which retain the screening plates 3 at a distance from each other matching the screening slot. In the present case, the flat mounting bars 6 and 12 extend continuously across the entire length of an edge of the screening surface 2 , but the flat mounting bars can also be divided into several sections. The flat mounting bars 6 and 12 are attachable to the fastening lips of a bucket frame. The screening plates 3 are as thin as possible from the standpoint of structural strength, thus providing a maximal capacity per unit area of the screening surface. The screening slots extend continuously across the entire distance between the flat mounting bars 6 , thus avoiding the formation of unnecessary obstacles to the material flow-through.
Present below the screening surface 2 are rotatable shafts 4 , fitted with projecting blades 5 which rotate along with the shafts 4 and extend through the screening slots to above the screening surface 2 . The blades 5 have an extent in the range of 1-40 mm above the screening surface 2 . With this dimensioning of blades, the blades are on the one hand enabled to convey through the sieve screen a material capable of fitting in the screening slots and, on the other hand, to push along the screening surface a material not fitting in the slots. In a preferred embodiment of the invention, the screening plates can be adjustable in the direction perpendicular to a plane surface extending by the shafts 4 for changing the extent of protrusion of the blades 5 above the screening surface 2 . The inter-shaft distances and the length of the blades 5 are preferably dimensioned in such a way that the entire volume of screening slots between the screening plates 3 will be swept by the blades 5 . Thereby, between the plates 3 remain no blind spots for the material to stick. Small blind spots can be tolerated, since, outside these spots, the blades 5 in any event take care of maintaining the sieve screen in a continuously open condition. Therefore, the only drawback of small blind spots is a slight reduction of the sieve screen capacity per unit area in case the blind spots are obstructed.
The shafts 4 are driven in the same direction, whereby the material not fitting through the sieve screen is continuously revolving in the same direction instead of building a plug on top of the screening surface. After the screening, the only items left inside the sieve screen bucket 1 are rocks or other hard pieces incapable of passing through the sieve screen.
In a sieve screen of the invention, the blades 5 are freely movable on the shafts 4 in axial direction. All that is transmitted by the shafts 4 to the blades 5 is a torque. The shafts 4 are polygonal in cross-section, and each blade 5 has a collar element, which extends around the shaft and from which projects the actual blade 5 . Accordingly, the blade 5 in all of its rotational positions, i.e. at all of the rotational angles of the shaft 4 , lies at least partially between the screening plates 3 under control of the screening plates. Hence, the screening plates 3 retain a position perpendicular to the screening surface 2 . Thus, the blades 5 are sort of like slabs having a thickness which is substantially equal to the width of a screening slot between the screening plates 3 .
The distance between the shafts 4 is slightly less than the diameter of a circle drawn by a tip of the blade 5 . Thus, the parallel shafts 4 must have the positions of their blades synchronized in such a way that the ends of the blades 5 do not coincide in the same slot. In FIG. 1 there is intentionally shown an incorrect position, wherein the ends of the blades are overlapped, i.e. would collide with each other unless said positional synchronization were present.
In order to have the slots between the screening plates 3 swept by the blades 5 without substantial blind spots, and without having to reduce the inter-shaft distance such that the synchronization of blades would become a problem, the screening surface 2 has been designed as a downward concave arch and possibly to be slightly undulating. In addition, it must be taken care of that between a lateral surface of the screening surface-approaching blade 5 and the screening surface be always left a sufficiently large angle, such that hard pieces not fitting in the screening slots become conveyed along the screening surface instead of being jammed between the blade and the screening surface. This is why the blades 5 taper in a wedge-like manner towards their rounded tips. The sides of blades 5 are substantially straight with an angle between the same in the range of 20-28°. This is also partly influenced by the fact that the blade must not extend above the screening surface higher than a certain maximum distance. There are other options of designing the blades, for example as tools crushing the material to be screened.
The screening plates 3 have their bottom edges provided with recesses for receiving the shafts 4 , whereby the screening plates 3 extend partially into a space between the shafts 4 . In a loaded condition, the screening plates 3 may be supported in their mid-sections on the shafts 4 , i.e. the recesses may have their bottoms leaning against the shafts 4 as necessary.
A turning motor for the shafts can be disposed in an enclosure at an upper portion of the bucket, and the rotation drive such as chains and gears can be disposed in an enclosure 11 at a side wall of the bucket. The earth material to be screened is collected into the bucket, and the bucket is turned over to a screening position in which the sieve screen is in a slightly tilted position for the material to be conveyed by the blades 5 on top of the screening surface 2 in a slightly uphill direction. In this case, the material does not become packed at the end in the conveying direction, but circulates on top of the sieve screen until all the material fitting through the sieve screen has vacated the bucket.
FIG. 4 shows in more detail the shape and disposition of a blade 5 on a square-shaped shaft 4 . Various angular positions of the blades are used for setting the blades in a spiral fashion on each shaft. The blades 5 have their square hole at an angle of 22.5 degrees relative to a center line of the blade. Accordingly, a single type of blade can be set on the shaft in eight different positions (four positions in each direction), whereby the minimum phase difference between two blades will be 45 degrees.
Unlike the others, the outermost screening plate 3 is designed to extend deep around and below the shafts 4 adjacent to the penetrations of fastening plates 7 . Hence, these screening plates 3 ′ provide mudguards which block the entrance of dirt into penetrations of the fastening plates 7 , and thereby to bearings 8 which are mounted on the outer sides of the fastening plates 7 .
The fastening plates 7 , and the shafts 4 , along with their blades 5 , fixed (bearing-mounted) thereon, make up a cartridge unit capable of being installed in a single entity from the rear side of the bucket 1 by pushing the fastening plates 7 in the direction of their plane into reception openings in frame plates 10 of the bucket and by securing the fastening plates 7 with bolts to the bucket's frame plates 10 . The fastening plates 7 are double-layered, such that the edges develop a staggered fastening flange. The fastening plates 7 make up internal walls for the drive enclosures 11 . After installation, the rear sides of the drive enclosures 11 are closed with rear walls 11 a . The screening plates 3 to be placed between the blades 5 are set in position one by one from a forward side of the bucket. Attached to the bucket frame are elastic flat mounting bars 12 of e.g. elastomer, whose grooves 13 take up ends 3 a of the screening plates 3 and guide these to their positions. Finally, the screening plates 3 are secured by fixing the flat mounting bars 6 on top of their ends 3 a.
New features of the invention will now be described with reference to FIGS. 3-7 . The invention differs from the foregoing prior art shown in FIGS. 1 and 2 in the sense that there is provided a possibility of various groupings for the screening plates 3 and the blades 5 according to a desired fraction size. The thickness of the blades 5 is designed to match a minimum fraction size. Various groupings of the screening plates 3 and the blades 5 can be used for doubling or tripling etc. the original minimum fraction size determined by a single blade thickness. Being freely movable in axial direction along the shaft 4 , the blades 5 can be grouped so as to have each time two (or three etc.) blades 5 adjacent to each other without an intervening gap. Respectively, two (or three etc.) screening plates 3 are each time set adjacent to each other without an intervening gap. Thus, the screening slots become respectively larger and fewer. However, it is possible to use the same screening plates and blades in constructing sieve screens capable of screening various fraction sizes. It is only the flat mounting bars 12 ( FIG. 2 ) that need be replaced in order to enable locations of the installation grooves 13 to match each time a desired grouping of the screening plates 3 .
FIG. 7 shows at each edge of the sieve screen two groups of three adjacent screening plates and in the middle the screening plates are set in adjacent to each other in pairs. The blades 5 are set adjacent to each other in pairs and the blades of each blade set are in the same screening slot. The adjacent blades can be in the same or different phases, i.e. positions of rotation angle. The number of screening plates and blades in each group need not match each other. The number of screening plates in each group can be varied for example in order to adapt the width of a sieve screen to the width of a bucket. Although, even in the process of screening coarser fractions, there could be just one screening plate between two adjacent screening slots, it is preferred from the standpoint of the strength and load-bearing capacity of a sieve screen that between two screening slots closest to each other there will be at least two screening plates 3 which are set adjacent to each other without an intervening gap. Depending on the thickness of a screening plate, the change of a fraction size according to the invention can also be implemented in such a way that there is just one screening plate 3 between two screening slots closest to each other.
As is apparent from the foregoing, the screening plates 3 extend in such a way into spaces between blade groups made up by the blades 5 that the blades are partially within the screening slots in all rotation angle positions of the shaft 4 , whereby the locations of blades and blade groups on the shaft 4 are determined by the screening plates. As a result, the blades set automatically in position in a direction of the shaft 4 and remain stationary. There will be no dimensioning problems for as long as the screening slots are sized according to the thickness of blade groups. A sieve screen of the invention can also be constructed in such a way that the gap left between screening plates 3 is larger than the thickness of a blade 5 or a blade group made up by adjacent blades, whereby rotation of the blade or the blade group between screening plates is guided either according to the screening plates or by means of separate mechanical spacer blocks mounted on the shaft. The mechanical spacer blocks can be e.g. half bushings of suitable length, from whose edges protrude fastening flanges which can be fastened with bolts against each other for thereby mounting the spacer blocks on the shaft 4 without removing the shafts.
What is achieved with the foregoing design is the important feature of the invention of being able to change the fraction size without removing the shafts 4 , by re-grouping the blades 5 and a necessary number of the screening plates 3 .
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The invention relates to a sieve screen, which can be positioned in a utility machine-operated screen bucket or in a screening station maneuverable with its own actuator. As shown in FIG. 7 , a plurality of screening plates ( 3 ) are spaced from each other and establish a screening surface ( 2 ), which is provided with screening slots and on top of which can be placed the material to be screened. Rotatable shafts ( 4 ) are present below the screening surface ( 2 ). The shafts ( 4 ) feature blades ( 5 ), which protrude from the shafts and extend through the screening slots to above the screening surface ( 2 ). Fraction size is adapted to be changed without removing the shafts ( 4 ), by re-grouping the blades ( 5 ) and a necessary number of the screening plates ( 3 ). The blades ( 5 ) can be grouped in such a way on the shafts ( 4 ) that at least two blades ( 5 ) are set adjacent to each other and the adjacent blades are located within the same screening slot.
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BACKGROUND OF THE INVENTION
The present invention relates to a copying apparatus which forms a latent image electrostatically on a photosensitive element in the form of a belt or a sheet by projecting a light image thereonto and then developing it and transferring the developed toner image onto a recording or copy sheet.
A copying apparatus of the type described conventionally employs a photosensitive element which may take the form of a drum, a belt or a sheet. Like a photosensitive drum, a photosensitive belt or sheet is driven continuously at a constant speed while undergoing various major copying steps such as charging, exposing, developing and transferring. A problem inherent in the use of a photosensitive belt or sheet is that slippage tends to occur between the belt or sheet and rollers adapted to feed it. The slippage is liable to prevent the actual processing timing in each of the copying steps from coinciding with predetermined ones. Complete recording may fail even after the predetermined timings are over or the recorded image may have deviations in small and/or large sections.
In a known system, a photosensitive element drive train is provided with a timing pulse generator (encoder) made up of a slotted plate and a photosensor. This system counts timing pulses from the generator from a start of copying operation and energizes various elements at timings based on the counts of the timing pulses. However, even though the mechanical elements may operate properly, a slippage whether temporary or continuous between the elongate photosensitve element and rollers will shift the actual charging, exposing and other timings either partly or entirely from the operating timings of the mechanism. This prevents a desired image pattern from being reproduced. During a series of continuous copying cycles, the shift or deviation will remain within the range of each copy if the count is reset copy by copy. If this count is not reset, however, the deviation in timing will accumulate and become more critical as the copying cycle is repeated.
SUMMARY OF THE INVENTION
A primary object of the present invention is, in a copying process using a photosensitive belt or a photosensitive sheet, to form an image pattern on the belt or sheet without any deviation.
Another object of the present invention is to record images on sheets without deviation.
Another object of the present invention is to reduce deviation of processing timings attributable to the photosensitive element.
A further object of the present invention is to avoid accumulation of deviation.
In one aspect of the present invention, there is provided a copying apparatus in which charge deposition and exposure for one document are performed on a photosensitive belt or sheet while keeping it stationary. The belt or sheet can be stretched with a relatively freely selectable surface configuration such as a flat or curved shape and, therefore, it can be positioned relatively easily such that image patterns are projected onto various areas of its surface without distortion or density variation in conformity with specific projection characteristics of an optical exposing system. In a simple design, the belt or sheet may have at least its exposure surface positioned flat. In this case, it is preferable that the exposure surface face a document, that a light source and mirrors with or without a slit be positioned between the exposure surface and document, and that such components for exposure be moved for exposure along the surface concerned. Another preferable arrangement may employ an optical system made up of a light source and an optical fiber head having light-converging optical fibers arranged into an integral array and, with these components, carry out exposure in the manner mentioned above. This second arrangement is particularly advantageous in that the optical exposing system requires only a small number of component elements, in that the positioning and the like are easy and in that images can be recorded with high resolution.
For depositing a charge on the belt or sheet before exposure, the belt or sheet may be driven at a constant speed relative to a charger which is energized. It is preferable, however, to mount the charger integrally on the optical exposing system and, while maintaining the belt or sheet stopped, move it together with the optical system so that the exposure surface on the stationary belt or sheet is charged and exposed simultaneously. This is because the stationary belt or sheet can be uniformly charged by the constant drive of a carriage (this can be carried out without deviation). Where the sheet or belt is moved relative to a stationary charger so as to be deposited with a charge, uneven charging cannot entirely be avoided because of possible slippage of the belt or sheet relative to drive rollers though the uneven charging due to slippage would not critically affect reproduced images. It is also desirable to mount on the carriage a high tension power source for applying a high voltage to the charger. If a high tension voltage source is fixed in place as conventional, it must be connected to the charger on the carriage by a movable and very long high tension wire. Connection of a low tension wire to the carriage suffices where such a power source is mounted on the carriage.
In this way, electrostatic latent images can be formed on the belt or sheet without any significant deviation or density fluctuation by a compact construction if the carriage has thereon a light converging optical fiber head, illumination lamp, charger and high tension power source and this carriage is driven to expose the stationary photosensitive surface to a image light.
The deviation of images reproduced on sheets may also be caused by improper timings of sheet feed and image transfer relative to the feed timing of a latent image on the belt or sheet. Furthermore, the developing timing and fixing timing (mainly in the case of flash fixing) affect the quality of reproduced images. These timings are liable to deviate from predetermined ones due to slippage of the belt or sheet which will be travelling during such processing steps.
Therefore, in another aspect of the present invention, there is provided a copying apparatus which predetermines major timings such as that of copy start by reading marks, slots, lugs, magnetic pieces or like indices provided to the belt or sheet. This provides a base point for the timing of each copying action and thereby avoids accumulation of deviation in timing in a continuous copying operation. Since precise timing at each processing step may fail to be determined merely by reading the indices on the belt or sheet, it is preferable to count pulses of a short period from the instant an index on the belt or sheet has been read and in this way determine each processing timing on the basis of the counts. In this case, if the count of timing pulses is compensated for the distance or time interval between the indices every time an index is read and, from the compensated count the counting operation is continued, accumulation of deviation in timing attributable to deviation in the feed of the belt or sheet can be minimized even in the processing of a single copy. Dislocation of an image pattern on a sheet is mainly caused by the feed of a sheet to a transfer station at an improper timing relative to the feed timing of a latent image (or vice versa). For this reason, it is desirable that the indices on the belt or sheet be located such that, after the counting of timing pulses which follows detection of one index, the count is compensated upon detection of a second index and, immediately after this compensation, feeding of a sheet is started. The count is compensated in accordance with the actual position of the belt or sheet before the starting point of a sheet feed timing.
An electrostatic copying apparatus embodying the present invention includes a photoconductive member, imaging means for forming an electrostatic image of an original document on the photoconductive member, developing means for developing the electrostatic image to form a toner image, transfer means for transferring the toner image to a copy sheet and a drive motor for driving the photoconductive member and is characterized by comprising mark means provided on the photoconductive member, sensor means for sensing the mark means and producing signals in response thereto, pulse generator means driven by the motor for generating timing pulses, counter means for counting the timing pulses, control means for controlling the imaging means, developing means and transfer means in accordance with predetermined counts in the counter means, and compensation means for resetting the counter means in response to a first signal from the sensor means, sensing a count in the counter means in response to a second signal from the sensor means and, when the sensed count is different from a predetermined value, setting the counter means to the predetermined value.
In accordance with the present invention, a drive motor for a photoconductive belt is energized for continuous rotation and connected to the belt through a clutch. The clutch is disengaged and the belt held stationary while an electrostatic image of an original document is formed on the belt. Then, clutch is engaged and the belt driven for developing the electrostatic image into a toner image and transferring and fixing the toner image to a copy sheet. The motor also drives a pulse generator which produces timing pulses. The timing pulses are counted by a counter. A control unit such as a microcomputer controls the operation of the apparatus in accordance with predetermined counts in the counter. Marks are provided on the belt in spaced relation. A compensation unit senses the number of timing pulses counted by the counter between sensing of the marks. If the number of timing pulses counted is within a predetermined range which contains a predetermined value but is different from the predetermined value, the predetermined value is set into the counter, thereby compensating for slippage of the belt relative to the motor. If the number of timing pulses counted is outside the predetermined range, an alarm is energized. Provision is also made for sensing a period of the timing pulses and energizing an alarm if the period is outside a predetermined range.
It is another object of the present invention to provide a generally improved electrostatic copying apparatus.
Other objects, together with the foregoing, are attained in the embodiments described in the following description and illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows in sectional side elevation a major part of the construction of a copying machine to which the present invention is applicable;
FIGS. 2a and 2b are enlarged perspectives of two different elements included in the copying machine;
FIGS. 3a, 3b, 3c form a block diagram showing a combination of a central control unit of the copying machine and its associated electric circuit elements;
FIG. 4 is a key for symbols shown in FIG. 3;
FIGS. 5a-l and 5a-z form a timing chart showing an operation for producing a single copy;
FIGS. 5b-l and 5b-z form a timing chart for producing a plurality of copies in a continuous operation;
FIGS. 6a-l, 6a-z and 6b are flow charts demonstrating the control of copying operation; and
FIG. 7 is a flow chart indicating a timing pulse monitoring flow which occurs in response to an interrupt.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the electrostatic copying apparatus of the present invention is susceptible of numerous physical embodiments, depending upon the environment and requirements of use, substantial numbers of the herein shown and described embodiments have been made, tested and used, and all have performed in an eminently satisfactory manner.
Referring to FIG. 1, there is shown a copying machine to which the present invention is applicable. The machine includes a photoconductive or photosensitive belt 1 passed over three feed rollers 2 1 -2 3 which are in turn connected through a clutch or belt clutch to a motor unit 3. The motor unit 3 has therein a gear reduction mechanism and a motor. A carriage (not shown) is movable on and along a pair of parallel guide bars 7 1 and 7 2 (though the guide bar 7 2 does not appear in the drawing) in parallel with the upper run of the belt 1 and a flat glass platen 8. A wire 9 is in driving connection with the movable carriage. Rigidly mounted on the carriage are a light source 4 in the form of a lamp, an optical fiber array or head 5 of the light converging type, a charger 6a and a power source 6b for the charger 6a. Supported by turn pulleys, the wire 9 is driven by the motor unit 3 through a clutch for a forward stroke (indicated by an arrow in the drawing) and a return stroke. As will be described, the lamp 4 remains turned on and the charger 6a energized while the carriage is travelling its forward stroke to illuminate an area of the photosensitive belt surface corresponding to a selected image size (e.g. format A3, B4, A4 or B5) on the glass platen 8 with a light image through the optical fiber head 5. During this period, the belt 1 is held stationary. With this system, charging and exposure of the belt 1 are carried out through the movement of the carriage. This kind of carriage drive can be performed at a stable speed without slippage and, therefore, permits an electrostatic latent image to be formed with high quality on the upper surface of the belt 1. After the exposure, the belt 1 moves in the counterclockwise direction and, at this instant, a developing unit 10 is activated to develop the latent image on the belt 1 into a toner image.
Where only one copy is desired, the belt 1 is driven continuously even after the development while a copy sheet is fed from a selected one of upper and lower sheets cassettes 12 1 and 12 2 by feed rollers 13 1 or 13 2 to registration rollers 14 and therefrom to a transfer charger 11. The timing of this sheet feed from the sheet cassette is such that the leading end of the sheet reaches the transfer charger 11 at the instant the leading end of the developed image on the moving belt 1 arrives at the transfer charger 11. Where "n" copies are to be produced in succession, the belt 1 is stopped when the first latent image has been developed and the second latent image is formed by exposure on the other half of the belt 1 which is then the upper half. Then the belt 1 is driven again so that the development of the second latent image and the transfer of the first toner image are carried out simultaneously. Thereafter, the belt 1 is stopped again for the third exposure which is followed by the development of the third latent image and transfer of the second toner image. Such a procedure will be repeated until "n-l" copies are produced. Then the final or n-th copy will be produced in the same way as the production of a single copy.
In the illustrated embodiment, such overlapped processing is made possible by making the length of the belt 1 double the length necessary for producing one copy which is the sum of the maximum allowable copying size and some marginal areas. Naturally, the belt 1 may be three times or more the length required for producing one copy. As viewed in FIG. 2a, a piece of aluminum foil 15 1 is bonded to a predetermined position of one of opposite lateral edge portions of the belt 1. Though not shown in the drawing, another piece of aluminum foil 15 2 is bonded to the same edge of the belt 1 but at a position which is distant from the foil piece 15 1 by 1/2 of the overall length along the belt edge. A reflection type photosensor 16 is fixed in place for detecting the foil pieces 15 1 and 15 2 . When the photosensor 16 senses the foil piece 15 1 or 15 2 on the movable belt 1, a start point of a series of copying actions will be determined, the counted value will be compensated, the copying actions will be stopped and, in this way, major operating timings of the machine will be controlled.
The motor unit 3 is designed continuously rotate during the copying operation of the machine. As shown in FIG. 2b, a slotted disc 17 is mounted on a shaft, gear or other constantly rotated mechanical element of the motor unit 3 while a photosensor 18 of the light transmitting type is so positioned as to sense the slots of the plate 17. Outputs of the photosensor 18 are delivered as timing pulses through an amplifier circuit for amplification and wave-shaping. In this embodiment, the slotted disc 17, photosensor 18 and amplifier circuit constitute a timing pulse generator. As will be discussed below, the precise timing of each of various copying steps is determined on the basis of the number of timing pulses counted. The counting operation will be started and the count compensated on the basis of the outputs of the photosensor 16.
A section indicated by a broken line E19 in FIG. 1 has therein a central control unit and major electric elements and circuits. They receive command signals and codes from a keyboard K20.
FIG. 3 shows the central control unit E19 and its associated major electrical control elements. The central control unit E19 is made up of a 1-chip microcomputer 19, semiconductive read-only memory or ROM 20 2 and a random access memory or RAM 20 1 having an I/O port. Connected with the microcomputer 19 are a pulse oscillator 21, the photosensors 16 and 18, a zero-cross detection circuit 22, a reset circuit 23, a lamp 24 1 (blue) indicating "copy enable", a lamp 24 2 (red) indicating "copy inhibit" and a 2-digit, 7-segment display 25. Various elements are connected in the same way with the I/O ports of the ROM 20 2 and RAM 20 1 . Connected with the ROM 20 2 are a set of movable and stationary key contacts 26 of the keyboard K20, display lamps 27 1 -27 5 and character displays 28 1 -28 3 . Connected with the RAM 20 1 are control output terminals 31 1 -31 16 and photosensors 32 1 -32 6 . The photosensor 32 1 detects separation of sheets, the photosensor 32 2 detects sheets in the upper cassette 12 1 , the photosensor 32 3 detects sheets in the lower cassette 12 2 , the photosensor 32 4 senses toner density and the photosensor 32 5 detects discharge of sheets. The symbols of the individual elements in FIG. 3 represent the circuits shown in FIG. 4. When the signal level at the input terminal of the reset circuit 23 becomes high or "1", a relay connected with a terminal 23 1 will be energized to turn on the power source for each DC circuit section. When the signal level becomes low or "0", the power supply will be cut off with the components 19, 20 1 , and 20 2 reset.
The ROM 20 2 and an internal ROM of the microcomputer 19 store therein program data for latching, reading and displaying changes in the states of the keyboard K20 and sensors in various sections in response to their output signals and constant data which will be referred to for such operation. Control timings will be described hereinafter concentrating particularly on the steps of charging, exposing, developing, sheet feeding and image transferring which are relevant to the present invention. Control timings for producing a single copy are shown in FIG. 5a. Those for producing multiple copies in succession are shown in FIG. 5b except for the final copy which will be produced by timings similar to those of FIG. 5a. It should be born in mind that the control timings of FIGS. 5a and 5b apply when copies of format A4 are to be produced. For the other formats, different constants related to the formats will be used and, hence, the control timings will have predetermined deviations from those of FIGS. 5a and 5b.
Referring to FIGS. 6a and 6b, the power source is first turned on to make the input signal level of the reset circuit 23 "1" (step 1 ). Then, whether the sensor 16 has detected the foil piece 15 1 (or 15 2 ) on the belt 1, or whether the belt 1 is in its home position is checked (step 2 ). If the belt 1 is displaced from the home position, the motor unit 3 will be energized and the belt clutch engaged to rotate the belt 1 until the sensor 16 senses the foil piece 15 1 or 15 2 (step 10 ). When the belt 1 is in or has reached the home position, the system awaits closing of a print switch (one of the keys 26). Upon closing of the print switch, the system starts its copying operation (step 4 ). First, the motor unit 3 is energized and an odd counter (referred to as odd counter n 1 hereinafter) is set to the count of the timing pulses (steps 5 and 6 ). The counter may be either an internal counter of the microcomputer or an independent counter. In this embodiment, use is made of a program counter consisting of a certain storage region of the microcomputer 6a which first stores "1" and, every time a timing pulse arrives, adds "1" to the stored data and replaces the stored data with the sum. As the count of the counter n 1 reaches a first predetermined value (Md 1 ), the counter is cleared and re-starts counting timing pulses while the lamp 4 is turned on and the charger 6a is supplied with voltage. At the instant a second predetermined value t 2 is reached, the clutch is engaged to drive the carriage. Then at a third predetermined value t 3 corresponding to the selected format, the clutch is disengaged and the lamp 4 and charger 6a are de-energized to complete the exposure. As the count reaches t 4 , the belt clutch is coupled to drive the belt 1. At a count t 5 , a bias voltage for development is applied. At a count t 6 , a turn solenoid and the clutch are energized to drive the carriage for return stroke and, at count t 7 , development begins. Then, at a count t 8 , the development is stopped and, at a count t 9 , whether the carriage has arrived at the home position is determined. For this purpose, a sensor responsive to the return of the carriage to the home position is employed. These actions occur at step 7 . Thereafter, the system waits until the sensor 16 senses the foil piece 15 2 (or 15 1 ) at steps 8 and 9 . Upon detection of the foil piece 15 2 , it is determined whether the preset number of copies is one or more (step 11 ). At the instant the sensor 16 has sensed the foil piece 15 2 , a fresh photosensitive area of the belt surface corresponding to one page will have reached a position beneath the glass platen 8.
If the preset copy number is one, meaning that continuous copying operation is needless (FIG. 5a), the count of the operating odd counter n 1 is compensated (steps 16 - 20 ). First, the counter n 1 has its count checked or sensed (step 17 ) regarding whether the count is equal to or different from a predetermined number 700, the number of timing pulses which should be counted at the end of travel of the belt 1 by a distance equal to 1/2 of its length without any slippage. If the count is equal to 700 meaning that the belt 1 did not slip, the operation advances to step 29 with the count unchanged. If different, the count is compared with the reference number or value 700 to obtain the absolute value |α| of the difference α (step 18 ) and whether the absolute value lies within a predetermined allowable range 50 is determined (step 19 ). If, so, the counter n 1 is loaded with 700 and caused to keep on counting (compensation of the count). If not, the following processing is interrupted to determine if the difference is too much to permit any further use of the machine (step 27 ) and, without causing a copy counter to upcount (step 28 ), the operation is interrupted and a predetermined procedure carried out (step 33 and onward). The machine is reset to its standby state without performing any further copying cycles. If desired, at step 27 or 28, a buzzer, lamp or other alarm may be energized to call a service person or indicate the need for inspection or repair. When the counter n 1 reaches a count t 10 , the feed rollers 13 2 are driven if the designated sheet cassette is the lower one 12 2 . If the designated sheet cassette is the upper one 12 1 , the feed rollers 13 1 are driven at a count t 11 (step 29 ) and then stopped at a count t 12 . At a count t 13 , image transfer and cleaning are started and, at a count t 14 , the sheet feed from the upper sheet cassette 12 1 is stopped (steps 30 and 31 ). Then, even if the sensor 16 detects the foil piece 15 1 on the belt 1, a power source for flash fixing is turned on at a count t 15 without compensating the count of the counter n 1 . At counts t 16 , t 17 and t 18 , a flash lamp 33 is triggered for dissipating the charge whereupon, at a count t 19 , the sheet feed and image transfer are stopped. At the instant the foil piece 15 2 has been detected, or upon arrival of two successive detection outputs after the compensation of the counter n 1 , the motor unit 3 is deactivated while charge-expelling and cleaning steps are completed. In this stop position, if the foil piece 15 1 (or 15 2 ) was detected by the sensor 16 at the first predetermined value Md 1 , the belt 1 will be in its home position wherein the sensor 16 detects the foil piece 15 2 (or 15 1 ). Therefore, by this time, a photosensitive area on the belt 1 different from that used for the first copying operation will have reached a position just below the glass platen 8. It will thus be seen that, even in the case of production of a single copy, two different photosensitive areas on the belt 1 are used alternately with even frequency. As will be noted, the end flag is checked immediately after the count t 18 and, if it indicates that the copying operation for selected number of copies has completed, termination at the aforementioned Md 4 will occur.
Now, when it is determined at the step 11 that a plurality of copies are to be produced continuously, whether the copying cycle is of the odd or even order is checked (step 12 ). If it is an even copying cycle Md 2 , Md 4 . . . ), the operation shown in FIG. 5b takes place. An even counter n 2 is set to the count while, based on this count, control timings for charge deposition and exposure are determined (steps 13 - 15 ). Whether the process can proceed is determined by checking whether the difference between the count of the counter n 1 and reference number 700 lies within the allowable range 50, and then the count of the counter n 1 is corrected or the processing is interrupted as already discussed (step 16 and onward). If the copying cycle is of an odd number (Md 3 , . . . ), the even counter n 1 is set to the count (steps 21 - 22 ) and control timings for charge deposition and exposure are determined on the basis of the count. Concurrently, whether the difference between the count of the counter n 2 and reference number 700 is within the allowable range 50 is determined to see whether the process can proceed. Then, as described, the count of the counter n 2 is corrected or the processing is stopped.
In this way, an odd counter and an even counter are used alternately in a continuous copying operation such that one of them is set and the other corrected or compensated every time the sensor 16 detects the foil piece 15 1 or 15 2 . Accordingly, as shown in FIG. 5b, an odd copy and an even copy are processed in an overlapped manner though the steps are different from each other. The same holds true when the belt 1 has a length corresponding to three times or more of the maximum allowable size.
Regardless of the intended number of copies, sheet feed setting occurs at a time remote from the time of counter setting. Nevertheless, exact positioning of a copy sheet is achievable relative to a toner image on the moving belt 1. This is because the count of the counter is corrected before sheet feed setting by reading a foil piece and the timing is corrected in correspondence with the actual position of the belt 1. A cumulative error up to that instant due to slippage of the belt 1 is cancelled. Additionally, the time interval between the reading of a foil piece and count correction and the sheet feed setting is very short.
Now, the charge deposition and exposure performed with the belt 1 held stationary permits a latent image to be formed on the belt 1 without any significant dislocation. Also, the correction of the count of timing pulses based on the detection of a foil piece promotes, mainly, exact positioning of a paper sheet relative to a toner image on the belt 1. Yet, the timing pulses are liable to be disturbed though the probability is not so large as that of the slippage of the belt 1. This tends to occur particularly when the drive system inclusive of the motor unit 3 has its operation disturbed during stopping of the belt 1 or when the output pulses of the encoder (timing pulse generator) become irregular. The result is disturbance of the count which makes an adequate processing sequence impractical.
With this in view, the embodiment mentioned hereinabove also has an interrupt flow for monitoring the timing pulses. Referring to FIG. 7 which shows this additional flow, the microcomputer 19 has an internal timer counter which is activated (step 2 ) when a timing pulse 1 coupled from the timing pulse generator 18 to its interrupt terminal INT. In this embodiment, the microcomputer 19 is the Intel 8049 while use is made of a 6 MHz quartz oscillator. The timer counter upcounts 80 μs pulses produced by frequency division within the microcomputer 19 as one unit, the microcomputer 19 awaiting interrupt until the next timing pulse arrives (step 3 ). Upon arrival of the second timing pulse, the count of the timer counter is shifted to a register R 0 (step 4 ) and the period of timing pulses is checked (step 5 ). If the actual period of the timing pulses lies within the allowable range of 4.5-5.5 msec which contains a reference timing pulse period which is 5 msec, it is determined proper and the processing advances to the next step (steps 6 and 7 ). If the actual pulse period is outside of the allowable range, the difference |β| of the actual and reference periods is determined (step 8 ). If this difference is 1.5 msec or more, 1 (one) is loaded in a register R 2 and the number of times this has occurred is stored therein by addition. When the number increases beyond 5 (five), a service person is called for or the need of inspection or repair is indicated by alarm while inhibiting an further copying operation. If the difference is less than 1.5 msec, a register R 1 stored 1 (one) and also the sum of these occurrences which may progressively increase. When this number goes above 10 (ten), the same actions as those of the first case will take place. It will be noted that the registers R 1 and R 2 are cleared when the actual pulse period remains within the range of 4.5-5.5 msec and, hence, the measure against such unusual condition is taken only when the abnormal timing pulses appear in succession 5 times or more or 10 times or more. The failure data is stored in a non-volatile memory (not shown).
A step 2' in the flow of FIG. 7 indicates a routine for checking timing pulses whose durations are excessively long. When the slotted disc 17 becomes unmovable for one reason or another such as disengagement from the shaft, the output level of the photosensor 18 will be "1" or "0". This is detected at the step 2' and, then, the operation immediately advances to the process for correcting the unusual condition. It should be born in mind that, though the duration of the timing pulses becomes 5 to 10 times longer than usual immediately before and after start and stop of the motor, such timing pulses are not checked and this condition is not determined unusual.
While in the foregoing embodiment the count of a counter is set for correction purpose to a given number larger than zero in the event an index on the belt has been detected, the correction may be made by clearing the count to zero. Furthermore, the count may be corrected to zero by switching the counters from one to the other so as to utilize the count of the other counter which is to start counting for the subsequent operation. For instance, concerning the timings t 10 -t 19 in FIG. 5a, the constant data may be determined in correspondence with counts which have the base point at Md 2 .
In summary, it will be seen that the present invention provides an improved electrostatic copying apparatus which overcomes the problems involved with sippage of a photoconductive belt or the like relative to a motor shaft which drives a timing pulse generator. Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.
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A drive motor (3) for a photoconductive belt (1) is energized for continuous rotation and connected to the belt (1) through a clutch. The clutch is disengaged and the belt (1) held stationary while an electrostatic image of an original document is formed on the belt (1). Then, the clutch is engaged and the belt (1) driven for developing the electrostatic image into a toner image and transferring and fixing the toner image to a copy sheet. The motor (3) also drives a pulse generator (18) which produces timing pulses. The timing pulses are counted by a counter. A control unit (E19) such as a microcomputer (19) controls the operation of the apparatus in accordance with predetermined counts in the counter. Marks (15 1 ), (15 2 ) are provided on the belt (1) in spaced relation. A compensation unit senses the number of timing pulses counted by the counter between sensing of the marks (15 1 ), (15 2 ). If the number of timing pulses counted is within a predetermined range which contains a predetermined value but is different from the predetermined value, the predetermined value is set into the counter, thereby compensating for slippage of the belt (1) relative to the motor (3). If the number of timing pulses counted is outside the predetermined range, an alarm is energized. Provision is also made for sensing a period of the timing pulses and energizing an alarm if the period is outside a predetermined range.
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BACKGROUND OF THE INVENTION
Drive-in facilities by means of which bank customers may transact their business without leaving their vehicles have become increasingly popular, particularly in suburban locations, to the point where two, three, or even more stations are required to accommodate the traffic; and where multiple stations are involved, it is extremely difficult to provide two or more teller stations in locations where the motorist can drive up to the teller station and transact business with the teller by means of an extensible drawer in which currency, deposit slips and the like may be transferred between the teller and the customer. To alleviate this problem, as well as conserve space and enhance traffic flow, remote customer stations have been provided in the form of islands having remote facilities for transferring items back and forth between the remote customer station and the teller station. In addition to increasing the number of customers who may transact their business at any given time, a lesser number of tellers is usually required in that one teller can service more than one customer station.
For the most part, vacuum systems are utilized to convey the items back and forth between the customer stations and the teller stations. Such vacuum systems are expensive to install and to operate, and the number and size of items which can be transported is relatively limited due to the size of the normally cylindrical containers required for travel through the vacuum lines. In addition, should one of the lines be plugged, either by one of the containers or by foreign materials inadvertently, or even deliberately, introduced into the vacuum lines, considerable difficulty is often encountered in removing the obstruction and any containers which might be trapped in the system by reason of the obstruction. Similar objections are encountered with other forms of moving conveyors, particularly those which move underground or are otherwise relatively unaccessible for maintenance and repair; and if a stoppage results due to a malfunction in only a portion of the system, the entire system may have to be shut down until the necessary parts can be obtained and the repairs made, which may put the system out of operation for a number of hours, days, or even weeks.
In contrast to the foregoing the instant invention provides an integrated conveyor system which is relatively inexpensive both insofar as initial cost is concerned as well as in its cost of operation, and which can be easily installed and service.
SUMMARY OF THE INVENTION
In accordance wth the present invention, as integrated conveyor system is provided in the form of vertical and horizontal modules or units which are relatively simple and inexpensive construction and which can be pre-fabricated and require minimum installation time and labor.
In its basic form, the system comprises a pair of vertical modules which are of essentially identical construction, longitudinally their lengths may vary, as may the operation controls, depending upon whether the module is utilized at the teller station or the customer station. Each module comprises a simple box-like frame mounting a pair of centrally disposed standards which support the sheaves about which the various sets of conveyor belts travel, together with the idler rolls which guide the sets of belts in cooperating sinuous paths with the deposit box entrapped therebetwen. Each of the modules is adapted to be seated upon a box receiving unit having a pivotally mounted scoop by means of which the box may be readily engaged by the lowermost end of the conveyor belts or, upon discharge of the box from the conveyor belts, the scoop acts to receive and position the box for handling by the customer or teller, as the case may be.
In similar fashion, the horizontal module comprises a box-like frame which mounts a guide track and a set of cooperating conveyor belts and idler rollers, together with a separate drive unit for the set of horizontal conveyor belts. At its opposite ends, the horizontal module mounts curved guide channels which act as translating means, the guide channels overlying the upper ends of the sets of conveyor belts in the vertical modules and serving to guide the box being conveyed in a arcuate path between the vertical sets of belts and the horizontal set of belts. The modules readily lend themselves to being fitted into hollow columns or beams, and by providing the columns and beams with one or more removable sides, the modules can be readily exposed for servicing and repair or, if necessary, the entire module may be readily removed and replaced. As such, the modules operate independently of each other, except to the extent that their drive motors, which are reversible, are interconnected for operation in unison through a common control circuit. Each module may be independently wired and the wiring for the several modules interconnected by detachable connectors to form the complete control circuit.
The conveying system of the present invention permits the use of a relatively large, rectangular deposit box capable of holding at one time all of the items involved in the great majority, if not all, of the banking transactions which might take place. The box will comprise a bottom with a hinged lid, preferably molded from plastic and provided with a snap-lock interengagement of the bottom and cover. While the snap-lock engagement wll normally hold the lid closed, the sets of opposing conveyor belts in the vertical modules also performs a clamping action to hold the top and bottom parts in closed position even though their snap-lock engagement may be faulty.
A significant feature of the invention is the sinuous path of travel followed by the sets of conveyor belts in the vertical modules, particularly when a deposit box is engaged therebetween, the spacing of the belt engaging idler rolls being such that the box will be moved back and forth in a sinuous path with the belts and idler rolls coacting to prevent the box from slipping or falling relative to the belts irrespective of whether it is being moved upwardly or downwardly. The speed of travel of the box is accurately controlled in both directions and the stopping of the belts relative to the discharge of the box from the lowermost end of either vertical module will be such as to retard the speed of the box and hence its impact as it is received in the underlying scoop.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view with parts broken away illustrating a typical installation utilizing a series of three integrated conveyor systems in accordance with the present invention.
FIG. 2 is a partial side elevational view, with portions broken away, of the lowermost end of a vertical module together with the underlying box receiving scoop mechanism.
FIG. 3 is a partial side elevational view with parts broken away taken from the left-hand side of FIG. 2.
FIG. 4 is a partial side elevational view, with parts broken away, illustrating the upper end of a vertical module and an end of the adjoining horizontal module.
FIG. 5 is an enlarged vertical sectional view taken along the line 5--5 of FIG. 4 illustrating the guide track and coacting set of conveyor belts for advancing the deposit box from one end to the other of the horizontal module.
FIG. 6 is an enlarged vertical sectional view taken along the line 6--6 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, which illustrates an exemplary installation of the integrated conveyor system of the present invention, the inside of the teller's station lies to the left of the window 1 which, in most instances, will comprise a window of the bank building. The installation illustrated comprises three customer stations 2, 3, and 4 located on the space apart islands 5, 6, and 7, respectively, which define drive-through roadways therebetween. Teller stations 8, 9, and 10 are located to the left of window 1, i.e., within the bank building, there being a corresponding teller station for each of the customer stations.
Hollow vertical columns 11, 12, and 13 project upwardly from the teller stations 8, 9, and 10, each of the hollow columns containing a vertical conveyor module to be hereinafter described in detail. Similarly, the hollow vertical conveyor module to be hereinafter described in detail. Similarly, the hollow vertical colums 14, 15, and 16 each contains a vertical conveyor module. The upper ends of the sets of vertical columns are interconnected by hollow beams 17, 18, and 19; and each of the hollow beams contains a horizontal conveyor module, also to be described in detail hereinafter. The hollow columns and beams serve to cover and protect the conveyor modules; and preferably they will be formed with hinged or removable panels so that the enclosed modules may be easily exposed for servicing and repair.
The vertical modules contained in the colums 11, 12, and 13 will be of identical construction, as will be the vertical modules contained in the columns 14, 15, and 16, although the lengths of the modules may differ, the vertical modules at the teller stations usually being shorter than the vertical modules at the customer stations due to the fact that the customer stations are usually at a lower elevation to accommodate a customer seated in a passenger vehicle. The horizontal beams 17, 18, and 19 will vary in length in accordance with the distance between the customer stations and correspoding teller stations, usually differing by fixed increments in accordance with the distance between adjacent islands, which preferably will be uniform. Essentially, the horizontal conveyor modules will be of identical construction but will vary in length depending upon the distance to be spanned. If desired, however, the horizontal modules may be divided into self-contained sections for convenience in handling and installation.
Referring next to FIGS. 2 and 3, each of the vertical modules comprising a box-like supporting frame, indicated generally at 20, having vertical corner posts 21 interconnected by horizontal brace members 22. The corner posts may be conveniently constructed of right-angle stock, as may the horizontal brace members, although the latter may also comprise flat stock, the various members being welded, bolted or otherwise secured together to form an essentially rigid box-like frame, which will be of a size to be received within the vertical columns.
An oposing pair of vertical supports 23 and 24 is mounted within the box-like frame, the vertical supports being spaced apart by a distance slightly greater than the width of the deposit box 25, as will be apparent from FIG. 2.
At their lowermost ends the supports 23 and 24 mount oppositely directed sets of brackets 26 and 27 which rotatably journal shafts 28 and 29 mounting sets of sheaves 30 and 31, respectively. Sets of endless conveyor belts 32 and 33 pass around the sheave sets 30 and 31, the sets of conveyor belts extending upwardly to the top of the module where, as seen in FIG. 4, they pass around sets of sheaves 34 and 35 mounted on shafts 36 and 37 rotatably journaled in brackets (not shown) mounted on the upper ends of the vertical supports 23 and 24. The shafts 36 and 37 also mount gear belt pulleys 38 and 39, respectively, which are engaged by gear belts 40 and 41, respectively, which in turn are driven by electric drive motors 41 and 43 mounting gear belt pulleys 44 and 45, respectively. Thus, the drive motor 42 drives the set of conveyor belts 32, whereas the drive motor 43 drives the set of conveyor belts 33. Preferably, the drive motors 42 and 43 will comprise fractional horsepower reversible synchronous motors since such motors are relatively inexpensive to purchase and to operate, and in addition they are of relatively small size and readily lend themselves to being mounted within the confines of the box-like supporting frame.
The vertical supports 23 and 24 also mount oppositely directed sets of idler rolls 46 amd 47, the idler rolls 46 lying in interdigitating relation with respect to the idler rolls 47, the sets of idler rolls being positioned to be contacted by the inner flights of the sets of conveyor belts 32 and 33, the innermost flights being indicated at 32a and 33a. The vertical distance between adjacent idler rolls 46, as well as between adjacent idler rolls 47, is somewhat greater than the length of the deposit box 25; and consequently the vertical distance between adjacent idler rolls 46 and 47, which lie in interdigitating relation, will be less than the length of the deposit box. In addition, the lateral spacing between the innermost surfaces of the rolls 46 and 47, will be less than the depth (top to bottom dimension) of the deposit box, which relationship of the idler belts causes the deposit box to travel in a sinuous path as it is moved vertically between the opposing innermost flights of the sets of conveyor belts 32 and 33. Thus, as illustrated in FIG. 4, as the leading end of the deposit box 25a comes into contact with the idler roll 46a, it is deflected to the right, effectively pivoting about the underlying opposing idler roll 47a. In order to permit the desired deflection of the deposit box, the sets of conveyor belts 32 and 33 will be formed from a material, such as polyurethane, which provides sufficient elasticity to permit the belts to stretch to accommodate the deflection of the deposit box. If the deposit box is traveling upwardly, its trailing end will pass beyond the idler roll 47a prior to the time its leading end contacts the idler roll 47b which deflects the deposit box in the opposite direction, the box effectively pivoting about idler roll 46a.
As will be evident by comparing the position of the deposit box 25a with that of deposit box 25b, also illustrated in FIG. 4, the interdigitating sets of idler rolls 46 and 47 cause the deposit box to travel in a sinuous path rather than in a straight line path; and it should be evident that in addition to being securely clamped between the innermost flights of the opposing sets of conveyor belts, the offset and interdigitating relation between the sets of idler rolls insure that the deposit box cannot slip or fall vertically. For example, slippage of the box 25b from the position illustrated in FIG. 4 is effectively prevented by idler roll 47b and the deflected inner flights of conveyor belts 33. Thus, irrespective of whether the deposit box is moving upwardly or downwardly, it is effectively constrained as it is deflected back and forth and hence caused to move in a sinuous path. Consequently, the deposit box is at all times under positive control and cannot slip or fall freely while moving in a vertical direction.
Positive control of the vertical movement of the deposit box is particularly important in discharging the box from the conveyor into the underlying box receiving unit, whether it be at the customer station or at the teller station. Referring to FIGS. 2 and 3, a box receiving unit 48 underlies the lowermost end of the vertical module. This unit has a curved wall 49 coacting with a scoop 50 which forms a seat for the lowermost end of the deposit box 25. The scoop 50 has a rearwardly projecting pair of arms which are pivotally connected to the undersurface 52 of the box receiving unit 48 by means of hinge member 53. When it is desired to insert the deposit box for delivery through the conveyor system, it is seated on the scoop in the manner illustrated in FIGS. 3 and 6, whereupon the customer or the teller, as the case may be, lifts upwardly on the scoop 50, which pivots about hinge 53, thereby causing the deposit box to ride upwardly along the curved wall 49 and enter the lowermost end of the vertical conveyor between the opposing inner flights of belts 32 and 33. As the scoop is pivoted upwardly, the flexible arm 54 of actuating switch 55 (FIG. 6) is contacted, as by means of one of the arms 51 of the scoop, thereby closing the actuating switch and energizing the drive motors for the conveyors. Thus, as the deposit box is lifted and inserted between the opposing sets of conveyor belts, the drive motors for the conveyor belts are actuated and the conveyor belts will be driven in the direction to transport the deposit box to the opposite station. In this connection, it will be understood that the actuating switch 55 at the teller station will actuate the drive motors in one direction, whereas the actuating switch at the customer station will actuate the drive motors in the opposite direction.
In the event the customer has difficulty in operating the scoop or fails to understand its operaton, a teller actuated solenoid 56 may be provided at the customer station, the solenoid having an arm 57 connected to the arms 51 of the scoop. Actuation of the solenoid will lift the scoop and hence cause the deposit box to be inserted in the conveyor. Alternatively, the teller may utilize the solenoid to recall a deposit box which has just been delivered to the customer station. A control switch 58 (FIG. 1) will be provided at the teller station to actuate the solenoid.
Discharge of the deposit box from the conveyor system into either of the box receiving units 48 is also automatically controlled. As seen in FIGS. 2 and 3, a switch 59 having a flexible arm 60 is mounted to be contacted by the deposit box 25 as it approaches the box receiving unit 48. As the box 25 travels downwardly for discharge, it will contact the arm 60 of switch 59 which will deenergize the drive motors and hence stop the movement of the conveyor belts. By vertical adjustment of the position of switch 59, the slow-down and stopping of the conveyor belts can be timed so that the speed of the descending box will be retarded and it will be released by the conveyor just prior to the conveyor belts coming to a complete stop, thereby permitting the deposit box to slip gently into contact with the underlying scoop, the box again assuming the position illustrated in FIGS. 2 and 6, in which position the box may be readily gripped and removed from the box receiving unit. Alternatively, a time delay relay can be included in the circuit.
Details of the horizontal module are illustrated in FIGS. 4 and 5, the module having a box-like supporting frame 61 which mounts an elongated guide track which, in the embodiment illustrated, comprises a pair of guide plates 62 and 63 (FIG. 5) having upstanding side rails 64 and 65, respectively, the side rails 64 and 65 being spaced apart by a distance sufficient to permit the deposit box 25 to be conveyed therebetween. A set of conveyor belts 66 travels along the upper surfaces of the guide plates 62 ad 63; and if desired, the guide plates 62 and 63 may be provided with longitudinal grooves 67 to assist in guiding the conveyor belts in the desired paths of travel. In addition, it is preferred to support the conveyor belts 66 at spaced apart intervals on idler rolls 68 which may be grooved, as at 69, to receive the conveyor belts. It is also preferred that the uppermost surfaces of the idler rolls 68 extend above the uppermost surfaces of guide plates 62 and 63, in the manner illustrated in FIG. 5, such arrangement serving to reduce the frictional drag on the conveyor belts as they travel along the guide plates 62 and 63.
The transfer of the deposit box between the vertical and horizontal modules is effected by means of curved translation members 70, one of which is illustrated in FIG. 4. The translation member 70 overlies the uppermost end of the vertical module and is positioned to guide the deposit box through an arc of 90°, such guiding movement being implemented by the conveyor belts 66 which also travel in an essentially curved path, being guided by guide rolls 71, 72 and 73, together with sheaves 74 about which the conveyor belts pass to define a return flight extending along the lower portion of the box-like support 61. The conveyor belts 66 are driven through sheaves 74 by means of gear belt pulley 75, gear belt 76, and gear belt pulley 77 operatively connected to fractional horse power reversible drive motor 78. A similar guide roll and sheave arrangement is provided at the opposite end of the box-like frame 61 but omitting the drive motor and drive means. Preferably the guide rolls 71, 72 and 73 will be identical to the idler rolls 68, including the provision of conveyor belt receiving grooves.
It should be evident from the construction just described that if the deposit box is being moved upwardly through one of the vertical modules, it will contact and be deflected in the direction of the conveyor belts 66 prior to its passage beyond the uppermost ends of the sets of vertical conveyor belts 32 and 33 and hence will be engaged and advanced by the conveyor belts 66 which, acting in conjunction with the curved translation member 70, turn the box to a horizontal position for travel along the guide plates 62 and 63. When the deposit box reaches the end of the horizontal module, the belts 66 and curve translation member 70 will again coact to direct the leading end of the box downwardly for engagement by the sets of belts in the underlying vertical module.
As should not be evident, the instant invention provides an integrated conveyor system composed of self-contained vertical and horizontal modules by means of which a deposit box or like container may be transported from one end of the system to the other, and returned, depending upon the direction in which the sets of conveyor belts are driven. The modules are of relatively simple and inexpensive construction and may be easily repaired or, should the necessity arise, the entire module may be readily removed and replaced as a unit, the only required connection being control circuits for the drive motors.
It will be understood that modifications may be made in the invention without departing from its spirit and purpose. A number of such modifications have already been set forth and others will undoubtedly occur to the skilled worker in the art upon reading specification. For example, the size and length of the modules does not constitute a limitation on the invention; and depending upon the distance to be traversed, the horizontal module may comprise two or more modular units. If two units are employed, it will be evident that each unit will have a translation means at only one end, the abutting ends simply having sheaves about which the sets of conveyor belts pass in close proximity to each other so that the box will readily pass from one set of belts to the other. Similarly, the curve translation members can be mounted on the uppermost ends of the vertical modules rather than on the ends of the horizontal module. Instead of a hinged scoop beneath the vertical modules to lift the deposit box, it may be lifted by a slide mechanism. Accordingly, it is not intended that the invention be limited other than in the manner set forth in the claims which follow.
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An integrated conveyor system for use in drive-in banks and the like for conveying a deposit box or similar receptacle from a remote customer station to a teller station, the system comprising a pair of self-contained vertical modules, one at the customer station and the other at the teller station, interconnected by a self-contained horizontal module, the vertical modules each incorporating opposing sets of conveyor belts arranged to convey the deposit box therebetween in a vertical path of travel, the sets of belts being guided by staggered sets of idler rolls positioned to cause the sets of belts and the box conveyed therebetween to move in a sinuous path of travel in such fashion that the box is securely engaged at all times by the sets of belts, the horizontal module having translation members at its opposite ends to move the box from vertical to horizontal, or from horizontal to vertical position, together with a belt conveyor for moving the box horizontally from one end of the module to the other, of actuating switches being provided to initiate movement of the various sets of conveyor belts upon the introduction of the box into one end of the system, and to deactivate the conveyor belts when the box is discharged at the opposite end of the system, together with teller controlled over-ride switches for starting and stopping the conveyors.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of Provisional Application Ser. No. 60/078,046, filed Mar. 16, 1998, and a divisional of application Ser. No. 09/267,610 filed Mar. 15, 1999, now U.S. Pat. No. 6,171,503.
FIELD OF THE INVENTION
This invention relates to the extraction of ammonia and amines from aqueous solution using tetraphenylborate salts, in particular sodium tetraphenylborate.
BACKGROUND OF THE INVENTION
Contaminants may enter the environment through discharge of industrial waste into a local water source, thereby imparting damaging and potentially devastating effects to the ecosystems which are dependent on the water source. Various methods have been proposed and implemented to reduce the level of contaminants present in water. However, such methods tend to be complicated and expensive, There is a need for alternative innovative technologies for removal of contaminants from waste water.
U.S. Pat. No. 4,695,387 (Berry et al.) discloses a process for continuous removal of ammonia from waste water using adsorption of ammonium ions to zeolite, and formation of ammonium phosphate from the adsorbed ammonium ions. The method employs a complex separation device having a plurality of chambers through which waste water must circulate. Although ammonium ion concentrations are reduced in waste water using this method, the removal of other nitrogen-containing contaminants from waste water is not addressed.
U.S. Pat. No. 5,641,413 (Momont et al., 1997) teaches removal of nitrogen from waste water having a high chemical oxygen demand. This method involves high temperature, high pressure oxidation and thermal denitrification to convert nitrogen-containing contaminants essentially to nitrogen gas. The process of U.S. Pat. No. 5,433,868 (Fassbender) employs a hydrothermal technique for removal of ammonia from water derived from sewage plant effluent. U.S. Pat. No. 5,407,655 (Sarritzu) discloses a process for recovery of pure (non-aqueous) ammonia from waste water through reaction with carbon dioxide, which also involves thermal decomposition, However, the high temperatures and pressures required in these processes necessitate the use of specialized tanks and equipment and thus tend to be expensive to conduct on a large scale.
U.S. Pat. No. 5,640,840 (Heitkamp et al., 1996) discloses a method for treatment of a liquid waste stream using microbial biodegradation whereby nitrogen-containing organic contaminants are ultimately converted to ammonia and carbon dioxide. The process involves flowing oxygenated waste water through a bed reactor supporting microbes capable of such biodegradation. This method requires the on-site presence of such a reactor, and recovery of purified water from the reactor may be a lengthy process.
Tetraphenylborates, particularly in the form of their alkali metal salts, are useful as counter ion components of cationic polymers in the field of non-linear optics (EP-A2-0 490 385), as polymerization initiators (U.S. Pat. No. 5,124,235), and as hydrophobic anionic functional groups dissolved in a polymeric matrix that is used in the separation of cesium and strontium from nuclear waste (U.S. Pat. No. 5,666,641). No work has heretofore been conducted to incorporate the use of tetraphenylborates in precipitation of ammonium ion or amines from waste water. All patents and publications referred to herein are expressly incorporated by reference.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method of extracting ammonia and organic amines from water in an effective and environmentally acceptable manner.
One aspect of the invention provides a method for treatment of contaminated water to remove a nitrogen-containing species selected from ammonium ion and amines, which comprises contacting the water with sodium tetraphenylborate under acidic conditions, preferably weakly acidic conditions such as a pH value of between 3 and 7, and separating the treated water from the resultant precipitate of a salt of tetraphenylborate and the nitrogen-containing species.
Another aspect of the invention provides a method for treatment of contaminated water to remove a nitrogen-containing species selected from ammonium ion and amines (which hereinafter includes imines and any other species wherein the nitrogen atom will receive a proton), which comprises adjusting the pH value of the water to the acidic range, providing a polymer comprising a polymer backbone having a tetraphenylborate salt immobilized thereon, contacting the water with the polymer to dissociate the tetraphenylborate salt to tetraphenylborate ions and cations, whereby the nitrogen-containing species binds with the tetraphenylborate ions, and separating the treated water from the polymer having the nitrogen-containing species bound thereto. Preferably, the tetraphenylborate salt is a salt of Li + , Na + , K + , H + , Ca +2 or Mg +2 . More preferably, Na + is the cation.
A further aspect of the invention provides a polymer for removing a nitrogen-containing species selected from ammonium ion and amines from contaminated water, which polymer comprises a polymer backbone having a tetraphenylborate salt immobilized thereon in the form of dissociated tetraphenylborate ions and cations.
According to another aspect of the invention, there is provided an article for use in the removal of ammonium ion or amine from contaminated water, which comprises a containment vehicle having associated therewith a quantity of a polymer as defined above. The polymer may be, for example, in the form of cross linked beads or inert particles, e.g. silica, surface treated to be coated with tetraphenylborate groups, and the containment vehicle comprises, for example, a porous bag for the beads, a structure for supporting a bed of the beads, or a bed of sand having the beads entrained therein.
The invention also provides an article which comprises a means for introducing a solid or gaseous contaminated water source containing ammonia or amines, and converting said source to aqueous state.
The term contaminated water should be understood to encompass any water source containing ammonium ion or amine, and the invention is contemplated for use in the removal of ammonium ion or amine from any such water source. Thus, the method may be used, for instance to remove ammonium ion or amine from ground water, non-point run-off water, mine infiltration water, industrial effluent, and any other type of contaminated water or waste water.
In the case where ammonium ions or amines may be air-borne, or found in any other gaseous medium, such compounds may be captured and converted from the gaseous medium to an aqueous medium and removed according to the invention. An example of such an application is in the case of volatile ammonia and amines which arise from animal waste in an environment such as an enclosed chicken barn. Additionally, ammonium ion or amines derived from a solid source, such as animal waste, could be solubilized in water and removed therefrom according to the invention.
The invention may also be used as a pre-concentration method for extracting and concentrating small traces of amines or ammonium ion before analysis therefor. The invention can thus be employed for test methods to quantify amines or ammonium ion. The invention may be used for analysis of street-drug mixtures, most of which are amines, whereby the amine component can be sequestered from an admixture. The invention may also be used for recovery of any amine which can be converted into a quaternary (charged) nitrogen system. Even (CH 3 ) 4 N + and related species having no N—H bond can be extracted using the method of the invention.
Amines which form insoluble salts with the tetraphenylborate anion and can be removed from aqueous media according to the invention include aliphatic amines such as alkylamines including methylamine, ethylamine, and propylamine, as well as guanidine and biguanidine; diamines of the formula NH 2 (CH 2 ) n NH 2 where n is an integer, such as ethylene diamine and propylene diamine; aromatic amines such as aniline and benzylamine; heterocyclic amines such as optionally substituted pyridine, pyramidine and pyrazine; polycyclic amines such as tropane and 1,4-diazabicyclo [2.2.2] octane (DABCOH), and also caffeine and nicotine.
The method is based on the formation of ammonium tetraphenylborate (NH 4 BPh 4 ), a salt which is very insoluble in water. When a slightly acidic aqueous solution of ammonia or an amine is added to an aqueous solution of sodium tetraphenylborate, an immediate, thick, white precipitate is formed. This precipitate of NH 4 BPh 4 is non-gelatinous, powdery but granular and is easily filtered. While NH 4 BPh 4 is insoluble in water, it is soluble in acetone and acetonitrile. It can be recrystallised from acetone/water mixtures (or from acetonitrile) and the crystals appear to be stable indefinitely, Preferred pH values for the aqueous solution range from about 3 to 7, particularly from about 4 to 6.
The nitrogen-containing species in the contaminated water is normally in the form of a soluble inorganic or organic ammonium salt or an amine and the method of the invention is particularly suited to the treatment of waste water streams, such as water polluted with industrial effluent or acid rain. Mine infiltration water also contains a high ammonia concentration when derived from prehistoric sources. Removal of ammonia is required prior to release of mine infiltration water into the environment.
Simple, apparently uncomplicated, salts of ammonia are rarely insoluble. When the crystal structure of NH 4 BPh 4 was completely determined ( Cand J Chem 58 (1980) 1355), it was shown to be a most extraordinary system, The NH 4 + and BPh 4 − ions stack in columns, alternating . . . NH 4 + . . . BPh 4 − . . . NH 4 + . . . BPh 4 − . . . with the NH 4 ions trapped in a cage produced with a pair of phenyl groups from each of the two adjacent BPh 4 − ions.
In itself this is not unusual, but within the columns the NH 4 + ions form four hydrogen bonds to the planes of the four phenyl rings in the surrounding cage. The short contact N—H . . . Ph, the careful IR work in the paper cited above and elegant thermodynamic measurements by L. Stavely in Oxford in the 1960's (ref in Cand J. Chem paper) makes it clear that this N—H . . . Ph interaction is a significant hydrogen bond. The favorable lattice energy for NH 4 BPh 4 , which is the source of its insolubility, comes then not only from a most favorable ion packing but also has a contribution from these hydrogen bonds.
The contribution from the hydrogen bonds is crucial and instrumental in the unique properties of NH 4 BPh 4 . Our subsequent X-ray structure determinations have shown that the N—H . . . Ph hydrogen bond (or a variant thereof is present in every case where the organo-ammonium salt has an N—H bond while the very favorable cage arrangement has often been seriously degraded. We have ascertained that the charge interaction (cation/anion) is necessary as is the N—H . . . Ph interaction, but the symmetrical cage is less vital.
In order to verify the efficiency of the method of the invention, model systems were examined with NH 4 + ions present in solution in concentrations ranging from 10 to 200 ppm. These solutions were treated with stoichiormetric quantities of NaBPh 4 , dissolved in water and then one additional drop of NaBPh 4 solution was added to ensure the presence of NaBPh 4 in excess. The solutions were allowed to settle and the residual ammonium ion concentration in the supematant was estimated by (a) Nessler's reagent, and (b) electrospray mass spectrometry seeking to detect the chloramine ion.
The Nessler's reagent studies gave consistent readings of a total residual NH 4 + concentration in the supernatant liquid ranging between 3 and 5 ppm. The mass spectrometric measurements confirmed these results since no ammonium ions were detected in the supematant liquid.
Thus, we concluded that NH 4 BPh 4 is so insoluble a material that when equimolar quantities of NH 4 + and BPh 4 − ions are mixed in solution, the concentration of residual NH 4 − ; ion (ions not complexed with BPh 4 − ) is very low, probably below 1 ppm.
The supematant liquid was examined by mass spectrometry over a period of several days. The boron species present in solution were easily identified by the natural isotopic abundance of boron. Over a period of a week, the levels of boron species in water stayed unchanged, and no new species were observed to emerge. These results confirm that the NH 4 BPh 4 solid is stable over an extended period of time when left in contact with water. These experiments were conducted at two representative temperatures, 25 and 35° C. and both experiments showed the same stability.
Following extraction of the ammonium ion or amine, the NaBPh 4 can be regenerated as outlined below.
The method depends on the fact that although NaBPh 4 is soluble in water and KBPh 4 is insoluble, KBPh 4 is isomorphous with NH 4 BPh 4 . This is not surprising since NH 4 + and K + occupy roughly tile same space in a crystal and are often mutually exchangeable in crystal structures.
While the two structures are isomorphous, the KBPh 4 system does not have the added advantage of four N—H . . . Ph hydrogen bonds. Thus, when KBPh 4 is stirred in a solution containing the NH 4 + ion, the equilibrium:
KBPh 4 (solid)+NH 4 + (soln)⇄NH 4 BPh 4 (solid)+K + (soln)
is strongly displaced to the right, that is towards the formation of NH 4 BPh 4 (solid).
The process involves stiring excess KBPh 4 in the NH 4 + solution until the concentration [NH 4 + ] starts to rise. The “spent” KBPh 4 is then filtered off. The spent KBPh 4 is then stirred with a mild base such as K 2 CO 3 , and the ammonia and amines are released, since once the ammonia or amine is neutralized it loses its charge and the main component of the lattice energy of the NH 4 BPh 4 salt is also lost. This simply reverses the equilibrium equation given above by the removal of the NH 4 + (soln) species from the system.
KBPh 4 is reformed by this process and the regenerated KBPh 4 can then be filtered and re-used. The filtrate contains the amines (and ammonia dissolved as NH 3 ) in solution. Acidification of the filtrate, followed by evaporation produces the solid ammonia and amine salts which can be collected and separated by differential vacuum sublimation.
In an alternative embodiment, sufficient Na 2 CO 3 solution is added to the separated NH 4 BPh 4 to neutralise all the ammonia and amines. NaBPh 4 remains in solution and the ammonia and amines can be removed by distillation (reduced pressure distillation to preserve the BPh 4 − ion). The NaBPh 4 already in solution is then available for re-use.
Another aspect of the invention relates to the use of functionalized polymers or surface modified particles for separation of ammonium ions and amine salts from water. In the former case this involves the use of a polymer which incorporates the BPh 4 − moiety. Such a polymer is preferably synthesized in the form of beads that consist of a lightly cross-linked network onto which BPh 4 − groups are attached. In the latter case, a suitable material such as particles of silica, alumina or titania, for example, are subjected to a surface modification so as to chemically attach BPh 4 − groups. Since it is important to maximize the interactions of the ammonium species with the BPh 4 − groups, it is necessary to employ a polymeric backbone with suitable hydrophobicity. Many backbones may be used ranging from somewhat hydrophobic polystyrene to the more hydrophilic polyethers.
Preferred polymer backbones include polystyrenes, polyethers and polyacrylamides, as well as silica, which is an inorganic polymer. Further copolymers including these and other hydrophobic and hydrophilic monomers may also be used. Particularly advantageous polymers include a porous, lightly cross-linked polystyrene resin that is functionalized to contain the tetraphenylborate functional group, and a more hydrophilic polyether polymer system also functionalized to contain the desired functional group. In addition, silica particles may be used as the support (or polymer) and may be surface-coated so as to feature the desired functional group as the active entity.
In all three cases, the tetraphenylborate functional group is preferably neutralized as the sodium salt. The binding of the ammonium species occurs by the displacement of the sodium ions, as in normal ion exchange processes. Alternatively, the other suitable cations may be used such as LI + , K + , H + , Ca +2 or Mg +2 . The cations bound to the tetraphenylborate ion are herein referred to generally as M. Regeneration of the materials can be accomplished by washing with concentrated Na 2 CO 3 (NaCl) solution, sodium bicarbonate solution or carbonic acid, for example, using methods known to those skilled in the art.
The phenyl groups of the tetraphenylborate group can optionally be substituted in para position by halo, e.g. fluoro or chloro, lower alkyl, e.g. methyl, or lower alkoxy, e.g. methoxy.
The following embodiments are presented as detailed examples of polymers for use in the invention.
All embodiments contain the active binding unit, tetraphenylborate, attached directly or indirectly to a polymeric backbone as shown schematically in formula (I) below. The tetraphenylborate moieties may be present as surface modifying agents or incorporated into a cross-linked resin. In formula (I), the tether (R 1 ) may be a lower alkyl group or simply a carbon-to-carbon bond, and M is a cation.
In a first embodiment, a polymer comprises cross-linked, functionazed polystyrene to which tetaphenylborate is tethered, and has the general formula:
wherein x refers to a styrene comonomer and is from 0 to 50 mol %, z refers to a cross linking agent and is from 1 to 10 mol %, y refers to a comonomer having the tethered tetraphenylborate group and is [100−(x+z)] mol %, and R 2 is a carbon-to-carbon bond or C 1 to C 6 alkyl, and M is a cation.
In a second embodiment, a polymer comprises a cross-linked polyether backbone with tetraphenylborate tethered thereto, and has the following repeating unit:
R 3 is C 1 -C 6 alkyl
R 4 is H or C 1 -C 6 alkyl,
R 5 is a carbon-to-carbon or C 1 -C 6 alkyl, and M is a cation.
More specifically, according to the second embodiment, a polymer comprises a polyether backbone with tetraphenylborate tethered thereto, and has repeating units as follows:
wherein:
each R 3 independently represents C 1 -C 6 alkyl,
R 4 is H or C 1 -C 6 alkyl,
R 5 is a carbon-to-carbon bond or C 1 -C 6 alkyl,
R 6 is phenyl or C 1 -C 6 alkyl
R 7 is phenyl C 1 -C 6 alkyl or cross linking unit,
M is a cation,
m is 0-50 mol % (comonomer),
p is 1 to 10 mol % (cross linking agent), and
n is [100−(m+p)] mol % (comonomer having the tethered tetraphenylborate group).
In a third embodiment a polymer comprises a silica backbone having pendant tetraphenylborate groups as shown below:
wherein R 8 is a carbon-to-carbon bond or C 1 -C 6 alkyl, and each R 9 independently represents C 1 -C 6 alkyl or H, and M is a cation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically the reactions involved in the preparation of a polystyrene derivatized with tetraphenylborate;
FIG. 2 shows the reaction schematics for preparing a polyether; and
FIG. 3 illustrates the formation of a silica with tetraphenylborate derivatization.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The use of functionalized cross-linked polystyrene beads as ion-exchange resins is a well-established industry (e.g., Dörfner, “Ion Exchangers”). Thus, the chemical techniques used in their preparation are well known in the art. Generally, the polystyrene-type (e.g. chloro-methylated) beads are prepared by suspension free radical polymerization techniques, generally using an organic initiator such as benzoyl peroxide or azobisisobutyronitrile (AIBN). Subsequent reactions can then be used to attach the desired functional group to the polystyrene backbone.
Free radical polymerization of p-bromostyrene, by suspension polymerization techniques known in the art, is used to prepare polymer beads approximately 100 to 400 microns in diameter. The bead size may be controlled by appropriate choice of surfactant and stirring design. Divinyl benzene is used as the cross-linking agent, In amounts varying between 1 and 10% by weight. A pore forming agent, such as butyl ether, ensures that the resulting beads are highly porous, as desired for effective sorbents. The density of functional groups, i.e., the number of sites/unit volume of resin, may be varied by copolymerization with styrene such that the resulting polymer will be a random copolymer of p-bromostyrene and styrene. The use of the comonomer serves to minimize additional cross-linking that could accompany subsequent functionalization reactions described below.
The brominated sites of the polymer beads are reacted with magnesium metal in ether to produce a Grignard reagent that reacts subsequently with BF 3 to form the polymer BF 2 derivative. This reaction of the polymer Grignard reagent with BF 3 requires careful control of reaction conditions, particularly stoichiometry, so as to minimize additional cross-linking. Such additional cross-linking has two adverse effects; (i) it decreases the density of functional groups, hence the ultimate binding capacity of the sorbent; and (ii) it makes the polymer more rigid, hence it is more difficult for the sorbate to penetrate the beads. Finally, reaction with another Grignard reagent, for example phenylmagnesium bromide, results in the formation of the desired tetraphenylborate functional sites. To remove the magnesium cations this polymer is washed with concentrated aqueous NaCl solution which results in the sodium salt, as desired. This sequence of reactions is shown in FIG. 1 . The individual reactions are efficient so that essentially 100% yield can be obtained at each stage.
Alternatively, a polymeric bead containing phenyl bromide groups is reacted with an alkyl lithium reagent to form the corresponding aryl lithium intermediate which may be reacted directly with triphenyl boron to give a polymeric matrix with pendant tetraphenyl borate groups.
The synthesis of cross linked beads with a more hydrophilic polyether is shown schematically in FIG. 2 . While styrene oxide is commercially available, the cross-linking agent used for the synthesis of the polyether resin beads, namely 1,4-diepoxybenzene, must be synthesized. Since epoxides are easily generated from alkenes by reaction with peroxy acids (e.g. peractic acid or, more commonly, meta-chloro-perbenzoic acid) the desired cross-linking agent can be obtained by the oxidation of divinyl benzene, These oxiranes, styrene oxide and 1,4-diepoxybenzene can be polymerized, for example, by a base-catalyzed ring opening mechanism. Thus, beads of poly(styrene-oxide) can be synthesized in a biphasic system using hydroxide and a phase transfer catalyst with styrene oxide and 1,4-diepoxybenzene. If desired, pore-forming agents may be included in the polymerization process.
The resultant polymer, or copolymer, can be brominated by reaction with bromine and iron (III) bromide. Finally, the triphenylboron moiety is added as described earlier using Grignard chemistry. The hydrophilicity of this system can be maximized, for example, by co-polymerizing propylene oxide to increase the relative oxygen to hydrocarbon ratio.
In another embodiment, a free-radical type polymerization can be used for this system. Controlling bead-size and tetraphenylborate density involves optimization of bromine, catalyst, and monomer concentrations as well as the solvent system and the practical aspects, such as stirring rate.
In yet another embodiment of the invention, silica particles are treated so that immobilized tetraphenylborate groups are attached to or synthesized on the surface of the silica particles. The use of silica as the support for functional groups is a common practice, for example, in the preparation of packing materials for chromatography columns. Hence, the chemistry is well developed and will be familiar to those skilled in the art.
Silica particles of various sizes are readily available from various commercial sources, e.g., Cabot. The surface hydroxyl groups are commonly used as reactive sites that can be used for the synthesis of various surface layers. For the preparation of silica that is surface-coated with the tetraphenylborate functional groups a chlorosilane coupling agent is synthesized that possesses the tetraphenylborate functional group. This coupling agent is then attached to the silica particles by reaction with the surface hydroxyl groups thereof. Alternatively, a commercially available bromophenyl silane coupling agent (R x Cl (3−x) SiPhBr) can be attached to the surface of the silica. By a series of subsequent reactions, similar to those described above for polystyrene, the bromo group is converted to form the tetraphenylborate. This is shown schematically in FIG. 3 .
The commercially available silane coupling agent R x Cl (3−x) SiPhBr can be converted to a Grignard reagent by reaction with magnesium metal in ether or a lithium reagent with an alkyl lithium. These intermediates can then be converted to the tetraphenylborate as described above. In a subsequent reaction with the surface hydroxyl groups of the silica particles chemical attachment of the modified tetraphenylborate moiety is attained.
The commercially available silane coupling agent R x Cl (3−x) SiPhBr is attached chemically to the silica surface and subsequent reactions at the bromo site, similar to those described above, result in the formation of the tetraphenylborate moiety.
Once the BPh 4 − ion is securely tethered to a polymer backbone it can be recycled relatively easily and cost effectively. The polymer is not water soluble but is water wettable. It is preferably in the form of small beads. A waste water stream may be passed, for instance, through a column containing the polymer, or a bag containing polymer beads may be dropped into water. Alternatively, the waste water can be passed through a bed of sand having the silica beads dispersed therein. The NH 4 + (and organo-ammonium) ions are bound by the tethered BPh 4 − ions. M 2+ ions will not be bound, and the BPh 4 − will bind all organo-diamines as mono-protonated species.
The ammonium and organo-ammonium species are released from the BPh 4 − interaction once the surrounding solution is made basic. Thus, once the spent polymer is washed with, for instance, Na 2 CO 3 solution, the ammonia and amines are released and the starting material regenerated. Alternatively and cheaper, the material can simply be swamped with Na 30 ions by washing it with concentrated NaCl solution. This expels the ammonium ions by force of Na + concentration. Washing the material with CO 2 in water (carbonic acid) is also feasible. This washes out ammonia as (NH 4 ) 2 CO 3 , the amines as amine carbonates/bicarbonates and regenerates an acidic material. The acidic material then later exchanges H + for NH 4 + .
EXAMPLES
Reagents and reactants were prepared as follows:
Ammonia-free Water
Ammonia-free water was used in preparation of all solutions and reagents in all experiments. Ammonia-free water was obtained as follows. Distilled water (1000 ml) was added to potassium permanganate (2.01 g) and anhydrous sodium carbonate (2.04 g). The solution was refluxed for approximately 1 hour. The intense purple initial solution boiled rapidly for 1 hour. The first portion (100 ml) of clear distillate was discarded and the remaining distillate was collected at a rate of about 100 ml/30 minutes.
Preparation of Standards and Solutions
Standard solutions of NH 4 Cl were prepared having different concentrations between 1 and 200 ppm NH 4 + . Standard curves for NH 4 + were determined via mass spectrometry, spectrometric analysis at wavelengths from 400 to 425 nm (412 nm preferred) using Nessler's reagent (an alkaline solution of mercuric iodide and potassium iodide), and by measurements obtained from NH 4 + specific electrodes. Standard solutions of sodium tetraphenylborate having between 1 and 200 ppm tetraphenylborate ion were also analysed via mass spectrometry.
Experiment 1
Formation of Ammonium Tetraphenylborate
A 100 ml aliquot of an NH 4 Cl solution having 200 ppm NH 4 + was added to a 100 ml aliquot of a sodium tetraphenylborate solution having 200 ppm equivalent tetraphenylborate ion. A small aliquot (about 5 ml) of the sodium tetraphenylborate solution was added to ensure excess of tetraphenylborate ion. The mixture was allowed to stand overnight to permit the ammonium tetraphenylborate salt to precipitate and settle. The mixture was additionally centrifuged and a clear supernatant was removed and analysed for NH 4 + using the above-described methods.
No ammonium ion was detected in the ammonia-free water using Nessler's reagent. Mass spectrophotometric methods detected ammonium ion in distilled water but not in the ammonia-free water prepared according to the above method.
During the formation of ammonium tetraphenylborate, a milky white precipitate was immediately formed when each of the sodium tetraphenylborate solutions was mixed with each of the ammonium chloride solutions. The supernatant derived following formation of ammonium tetraphenylborate was also found to be free of ammonium ion when analysed using mass spectrophotometric methods. This indicates that all of the ammonium ion present in the solution was precipitated out as the tetraphenylborate salt.
It was noted that during mass spectrophotometric analysis, at approximately pH 10, in the presence of chlorine. NH 4 + forms Cl—NH 2 . Cl—NH 2 binds to the tetraphenylborate ion. Thus, the removal of this molecule and other similar inorganic nitrogen-containing compounds from waste water through insoluble salt formation with the tetraphenylborate ion falls within the scope of the invention.
Experiment 2
Effect of pH, Temperature and Time on Formation of Ammonium Tetraphenylborate
Aliquots (100 ml) of solutions having either 100 or 200 ppm ammonium ion were adjusted with dilute HCl to pH values between 4 and 6. An aliquot (100 ml) of a solution containing the equivalent strength of sodium tetraphenylborate was added to each solution of ammonium ion. An extra 5 ml of the sodium tetraphenylborate solution was added to each mixture to ensure excess of the tetraphenylborate ion. The solutions were allowed to settle overnight and thereafter the supernatant was tested for ammonium ion spectrophotometrically using Nessler's reagent. Table 1 shows the resulting ammonium ion content of the supernatant for each solution.
TABLE 1
Clearance of ammonium ion by tetraphenylborate at
different pH values
Initial [NH 4 + ]
Supernatant [NH 4 + ]
(ppm)
pH
(ppm)
100
4.0
3
200
4.1
2-3
100
5.3
3
200
5.2
3
100
6.0
3
All ammonium ion solutions having pH values ranging between 4 and 6 showed nearly complete clearance of ammonium ion from solution when sodium tetraphenylborate was added.
Solutions of 100 and 200 ppm ammonium ion were again combined with sodium tetraphenylborate solutions, as above. pH values were adjusted to between 4 and 6. Aliquots of each solution were incubated for between 2 and 5 days in a thermostatically controlled water bath at 30° C., 35° C. or 40° C. When supernatants were analysed for residual [NH 4 + ] using Nessler's reagent, all fell within the range of from 2 to 4 ppm.
Long term stability of the ammonium tetraphenylborate salt in aqueous solution was tested by mixing a 200 ppm solution of ammonium ion with a 200 ppm sodium tetraphenylborate solution, as described above. Initial residual [NH 4 + ] was determined as 6 ppm. The mixture, including the ammonium tetraphenylborate precipitate was allowed to sit for 48 hours, and for an additional 1 week. No change in residual [NH 4 + ] occurred in this time period, and no change in the boron content of the supernatant was detected (as determined by mass spectroscopy), indicating that free boron was not arising from the precipitate and that the precipitate is thus relatively stable over time.
It was noted that the ammonium ion specific electrode did not provide reliable readings when the tetraphenylborate ion was present in the solution. Thus, the spectrophotometric analysis using Nessler's reagent was used to assess ammonium ion concentration.
Experiment 3
Synthesis of Polystyrene Having Tethered Tetraphenylborate
Poly(4-bromostyrene) was synthesized directly from the monomer by standard free-radical techniques. 240 mg (1.3 mmol aryl bromide) of vacuum-oven dried poly (4-bromostyrene) was dissolved at room temperature in 20 ml of dry tetrahydrofuran freshly distiled from a standard sodium/benzophenone complex all in an ultrapure nitrogen atmosphere. The reaction temperature was reduced to −78° C. in a dry ice/acetone bath and 1.1 ml of a 1.3M solution of sec-butyl lithium (1.4 mmol or ca. 10% excess) was added dropwise over 1-2 minutes.
The reaction was left to stir at low temperature for four hours whereupon an aliquot was removed and quenched in acidified water. The poly (styryl lithium) intermediate product crosslinked suggesting a terpolymer of cross-linked styrene, debrominated styrene and possibly unreacted 4-bromostyrene. A new peak in the phenyl fingerprint infrared spectrum at 700 wavenumbers, when paired with a peak at about 820 wavenumbers indicated the formation of the “proton-trapped” lithiation intermediate (polystyrene).
6 . 0 ml triphenyl boron solution (0.25M in THF or 1.5 mmol—used as received from Aldrich) was added to the reaction mixture at −78° C. and the reaction mixture was allowed to warm to ambient conditions overnight. A sandy colored precipitate with a faintly cloudy supernatant was observed 12 hours after the triphenyl boron addition.
The reaction was quenched in rapidly stirred distilled water giving rise to small polymeric particles (295 mg dry mass) which give IR spectra indicative of successful functionalization (eg mono-substituted phenyl groups). The particles were swellable on immersion in tetrahydrofuran, but did not redissolve indicating a cross-linked resin. Based on I.R. analysis, the product was determined to be a cross-linked polystyrene having a minimum of 25% functionalization by tethered tetraphenylborate. Both the polymeric starting material and regular homopolystyrone are very soluble in tetrahydrofuran. The aqueous fraction was blue-tinged and otherwise transparent. On evaporation of the water, a film and some solid residue remained, indicative of tetraphenylborate side reactions and non-crosslinked polymer.
The results of I.R. spectral analysis for intermediate and final products are as follows:
Poly(4-bromostyrene)
3629.93
3019.95
2925.12
2851.36
2360.05
1895.70
1772.09
1652.73
1588.55
1486.02
1448.27
1408.21
1362.52
1180.26
1102.23
1073.68
1009.23
941.23
907.44
821.81
755.20
718.08
667.99
630.66
541.98
END 25 PEAK(S) FOUND
Lithiation quenched in acidified water
3447.29
2922.95
1635.75
1486.93
1456.97
1448.14
1437.00
1407.82
1180.47
1073.76
1009.34
819.10
757.08
717.05
699.63
668.13
539.90
END 17 PEAK(S) FOUND
Cloudy supernatant 15 hours after triphenyl boron addition (film-dried in vacuo)
3543.08
3043.99
2927.31
1897.47
1599.33
1485.74
1442.37
1406.32
1252.20
1179.41
1145.99
1111.66
1071.63
1027.26
1009.08
884.54
823.71
744.56
702.05
679.49
615.98
601.90
581.13
542.11
END 24 PEAK(S) FOUND
Precipitate in water dried vacuo pellet
3567.85
3020.20
2921.70
2847.54
1894.95
1700.15
1653.05
1599.49
1485.80
1448.24
1431.72
1407.05
1240.35
1181.21
1102.62
1073.05
1008.93
885.68
819.09
737.15
716.40
699.70
649.65
609.24
542.16
END 25 PEAK(S) FOUND
The precipitate was tested in the following manner: (Test 1); 2 ml of an aqueous solution of ammonium chloride (115 ppm) was stirred overnight with 30 mg of the polymeric precipitate in an airtight vial. (Test 2): 5 ml of the ammonium chloride solution were added to 20 mg of the aqueous fraction residue from the above reaction. (Control): stock ammonium chloride solution was reserved.
Two aliquots (300 microliters) were then withdrawn from the liquid of each of tests 1 and 2 and the control and were tested with one drop of Nessler's solution. The control and test 2 assays (four total) turned red/orange on addition of Nessler's solution (yellow) indicating high concentrations of ammonium cations. The final colour of the test 1 assays was yellow/orange, indicating a lower concentration of ammonium cations. This test confirms that the polymeric product sequesters ammonium cations from aqueous solutions.
Experiment 4
The high-angle, low temperature, X-ray crystal structures of four representative organo-ammonium tetraphenylborate salts were studied for the purpose of defining the N—H . . . (π)phenyl interaction. More specifically the structures of the ammonium, guanidinium [(NH 2 ) 3 C] + , biguanidinium [((NH 2 ) 2 C) 2 N] + , and DABCOH + (mono-protonated 1,4-diazabicyclo[2.2.2]octane) [HN(CH 2 ) 3 N] + , tetraphenylborate salts were examined by X-ray diffraction using the charge-density, multipole refinement techniques. The X-ray data were collected on a R-Axisli imaging plate system at −120° C. with Mo—Ka radiation to sin(θ)/λ=1.0 cm −1 .
The X—H . . . π(phenyl) interactions were observed in the resulting deformation density maps. The parameters from the multipole refinements were then used to determine and quantity the topological features of the interaction, using Bader's theory of “Atoms in Molecules” (Bader, R. F. W. Atoms in Molecules—A Quantum Theory OUP, England, 1990; Bader R. F. W. Chem. Rev. 1991, 91, 893; Bader, R. F. W. J Phys. Chem. (A) 1998, 102, 7314). This showed that there was a definite, identifiable N—H . . . π(phenyl) hydrogen-bonding interaction between the ammonium or organo-ammonium cation and the (π) system of the phenyl ring(s). The XDPROP program in the XD package (Koritssnszky, T.; Howard, S. T.; Richter T. Mallinson, P. R.; Su, Z.; Hansen, N. K. XD, A Computer Program Package for Multipole Refinement and Analysis of Charge Densities from X-ray Diffraction Data 1995) was used for this. In the four salts there are 14 N—H . . . π(phenyl) interactions and in every N—H . . . π(phenyl) interaction, a (3-1) bond critical point was found between the (H) and π(phenyl) species. XDPROP was then used to locate the bond path (path of maximum electron density) on either side of these critical points. In every case, the path traveled in one direction back to the N—H system and traveled smoothly on to the (X) species in the opposite direction. The value of the electron density (p b (r)) and the Laplacian (∇ 2 p b (r)) were calculated at each of the critical points. The values of the Laplacian ((∇ 2 p b (r)) in all cases are positive, indicating the expected closed-shell nature of the interactions The values place the N—H . . . π(Ph) interactions as slightly weaker in energy than the conventional N—H . . . N hydrogen bonds but from both the topology and the critical point values the N—H . . . π(Ph) interactions are clearly hydrogen bonds.
The geometries of these four salts are representative of all the organo-ammonium tetraphenyl borates salts and the formation of this N—H . . . π(phenyl) interaction is characteristic in the formation and precipitation of the organo-ammonium tetraphenylborate salts.
In conclusion, according to the invention, NH 4 + and amines can be removed from waste water through insoluble salt formation with the tetraphenylborate ion. The ammonium tetraphenylborate salt is stable over long periods in aqueous solution. Tethering the tetraphenylborate ion in a polymer is useful in the removal of NH 4 + and amines from waste streams. Tetraphenylborate ion which is tethered to a polymeric backbone can be used for removal of NH 4 + and amines from waste water and can be regenerated by release of the NH 4 + and amines therefrom, thereby providing inexpensive and beneficial means to environmentally treat industrial, agricultural and other waste water or streams.
While the invention has been described in detail with reference to certain preferred embodiments thereof, it will be apparent to those skilled in the art that modifications and variations are within the spirit and scope of that which is described and claimed.
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A method of removing ammonium ions or amines from contaminated water includes treating the water with sodium tetraphenylborate under acidic conditions. Advantageously, the tetraphenylborate is immobilized on polymer beads and the water is contacted with the beads or passed through a bed of the beads.
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CROSS REFERENCE TO PRIOR APPLICATIONS
This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2012/059748, filed on May 24, 2012 and which claims benefit to European Patent Application No. 11167901.5, filed on May 27, 2011. The International Application was published in German on Dec. 6, 2012 as WO 2012/163804 A1 under PCT Article 21(2).
FIELD
The present invention relates to a process for producing a composite material (composite) which is obtainable by sintering a composition containing a hardness carrier and a base binder alloy based on FeCoNi or FeNi. The present invention also relates to a sintered composite material which can be obtained by the process and its use for tools or parts, such as forming tools, comminution tools or machining tools (cutting machining tools).
Hard metal (cemented carbide; cemented hard material) is a sintered composite material composed of hardness carriers such as carbides and a binder alloy. Hard metals have a very wide variety of uses and are used, for example, for machining virtually all known materials. Hard metals can also be used, for example, as a structural component, as a forming tool or a comminution tool or for a wide variety of other purposes where wear resistance, mechanical strength or high temperature resistance are particularly important. A frequent field of application is the machining of metallic materials. Here, temperatures exceeding 800° C. occur locally as a result of cutting, forming and frictional processes. In other cases, forming of metallic workpieces is carried out at high temperatures, for example, in forging, wire drawing or rolling. The tool is here subject to mechanical stress which can lead to deformation of the hard metal tool. High temperature creep resistance (in practice, hot hardness is usually determined as a substitute) is therefore an important property of the hard metal tool. The fracture toughness (K 1 C) is also, however, an important parameter in all applications since the tool or part cannot otherwise withstand peak mechanical stresses and can break. Wear resistance, hot hardness, fracture toughness and strength associated therewith (the latter usually reported as transrupture strength) can be adjusted via the size of the carbide phase and its proportion in the hard metal composition.
The properties of the hard metals also depend greatly on the binder alloy used. Fracture toughness, corrosion and hot hardness are determined mainly by the nature and basis of the binder alloy. The present invention relates to novel hard metals having a FeNi- or a FeCoNi-based binder alloy, which in terms of hardness (Vickers hardness in accordance with ISO 3878), fracture toughness (K 1 C, calculated by the formula of Shetty from the crack lengths and the size of the Vickers hardness indentation) and also hot hardness corresponds to the properties of the hitherto customary hard metals having a Co-based binder alloy.
For various reasons, cobalt is replaced as a base alloy by other base binder alloys in specific hard metals. The term “base binder alloy” also encompasses pure metals having unavoidable impurities, for example, obtainable as commercially available Ni and cobalt metal powders.
Ni metal powders are, for example, used as a base alloy for producing hard metals which are corrosion-resistant in acids, oxidation-resistant or nonmagnetizable. Liquid-phase sintering results in formation of a binder alloy based on Ni. This binder alloy contains elements such as W, Co, Cr, Mo or others which have been added, for example, as metal powders or as a carbide to the hard metal mix, and whose contents lead to the Ni-based alloy, formed from pure Ni by alloying during liquid-phase sintering. Compared to pure nickel, these elements lead to better corrosion resistance. Hard metals having Ni as base binder alloy cannot be universally employed because of their low hardness values compared to materials bound using Co-based alloys. Hard metals bound using Ni-based alloys furthermore have comparatively low hot hardness. They are therefore not employed in machining of metallic materials.
FeCoNi-based alloys are furthermore known as hard metal binders. However, these have the disadvantage of low K 1 C values which are proportional to the transrupture strength according to the Griffith equation up to binder contents of about 12% by weight. The K 1 C values of a hard metal composed of a hardness carrier based on tungsten carbide (average powder diameter: 0.6 μm) together with 7.5% of FeCoNi 40/20/40 are thus in the range from 8.2 to 9.5 MPa m 1/2 , while a hard metal having the same proportion by volume of cobalt (corresponding to 8% by weight due to the higher density of cobalt compared to FeCoNi 40/20/40) achieves a K 1 C of 9.5 MPa m 1/2 .
Hot hardness of hard metals having FeCoNi-based alloys as binder is usually lower at higher temperatures than those of hard metals bound using cobalt-based alloys.
FeNi-based alloys are also known as binders. US 2002/0112896 A1 describes FeNi alloys based on from 35 to 65% of Ni and from 65 to 35% of Fe. The room-temperature strength of the FeNi 50/50 base alloy described is, however, comparatively low; a hard metal containing 7.4% of FeNi 50/50 (proportion by volume of the binder corresponding to 8% by weight of cobalt due to the lower density of FeNi 50/50) thus has a K 1 C of only 8.5 MPa m 1/2 .
FeNi-based alloys comprising from 10 to 50% of Ni and from 90 to 50% of Fe are furthermore described in the thesis of Wittmann (Technical University of Vienna). These have, for example, at 15% of Ni and 85% of Fe, very high K 1 C values (above those which can be achieved using cobalt as base binder alloy; see results obtained by Wittmann, evaluated and published in: L. Prakash and B. Gries, Proceedings 17th Plansee Seminar 2009, Vol. 2, HM 5/1). This also applies to a FeNi 75/25 (see above reference, designated there as “A2500”). The hot hardness of hard metals having Fe-rich FeNi-based binder alloys at above 400° C. is, however, significantly below those of materials bound using Co-based alloys; this is made clear by the example of a base alloy of FeNi 82/18 (Proceedings International Conference on Tungsten, Refractory and Hard Metals, Washington, 2008, designated there as “M1800”).
An attempt to explain the dependence of the hot hardness of hard metals on the composition of the FeCoNi-based alloys used looks at the maximum solubility of tungsten in the binder metal alloy which can be established after sintering of the hard metal (B. Gries, Proceedings EUROPM 2009 Copenhagen, Oct. 10-12, 2009). According thereto, the maximum hot hardness of hard metals having a FeNi-based alloy would have to be that of a binder alloy composed of pure Ni since the maximum solubility of tungsten in the binder alloy, about 25% by weight, is here attained. In practice, however, hard metals having a FeNi 50/50 base alloy having a tungsten solubility in the binder alloy of not more than 19.4% are equivalent in terms of the hot hardness with those having a cobalt-based alloy (maximum of 20% of W in the binder alloy). Despite the still higher solubility of tungsten, hard metals having Ni-based alloys are inferior to both those mentioned above in terms of the hot hardness and are therefore not used for applications where high hot hardness is important, for example, in cutting machining of metals.
EP 1 488 020 B1 describes FeCoNi-based alloys containing from 10 to 75% of Co as the hard metal binder and having an fcc structure for specific machining tasks; these alloys are said to reduce the adhesion wear occurring in the cutting machining of specific steels. The hot hardnesses of such hard metals comprising austenitic FeCoNi-based alloys are significantly inferior to those of materials comprising cobalt-based alloys. It can furthermore be assumed that the strength values of hard metals comprising these austenitic binder alloys will additionally be lower than those of hard metals bound using a cobalt-based alloy.
WO 2010/046224 A2 describes the use of molybdenum-doped pulverulent metal powders having a FeCoNi, CoNi and Ni basis, alloyed with molybdenum. However, above 400° C., the hot hardness of a WC and 8% of Co with 82% of the maximum magnetic saturation is not quite attained ( FIG. 2 of WO 2010/046224 A2). In addition, the K 1 C is very highly dependent on the carbon content of the hard metal (Example 4 of WO 2010/046224 A2), which, in industrial practice of sintering, tends to fluctuate. The reliable attainment of the required properties of hardness, K 1 C and hot hardness thus depends sensitively on controlling the carbon balance, which cannot always be ensured under industrial conditions.
In summary, it can be said that neither Ni-, FeNi- nor FeCoNi-based alloys as hard metal binders lead to universally and industrially usable hard metals which are comparable simultaneously in terms of the aspects K 1 C, hardness and hot hardness to those bound by means of binder alloys based on cobalt. Due to health hazards posed by cobalt and also for reasons of conservation of resources, it would be desirable to replace cobalt as binder alloy basis as completely as possible by FeNi or FeNi with small proportions of cobalt, if possible, below 10%. Contents of iron in the binder alloy and in the base binder alloy lead, in particular, to a reduction in or avoidance of the generation of hyperoxide radicals as are formed in the case of contact corrosion of WC with cobalt in the presence of water and oxygen.
A statistically significant increased occurrence of pulmonary fibrosis associated with handling dusts of hard metal has also been observed in the hard metals industry. The disease is also referred to as “hard metal lung”. In conventional production of hard metal via powder-metallurgical production processes, i.e., pressing and sintering of pulverulent hard metal formulations, respirable dusts are liberated as a consequence of the process. If grinding of the sintered or presintered state of the hard metal is employed, very fine, respirable dusts (grinding dusts) are likewise formed. Particularly in the case of predominantly cobalt-containing hard metals, acute inhalation toxicity can additionally occur in grinding of presintered hard metals or sintered hard metals.
SUMMARY
An aspect of the present invention is to improve occupational health by providing hard metals, i.e., sintered composite materials, which have reduced acute toxicity. A further aspect of the present invention is to provide a process for producing a composite material which leads to hard metals which, both in terms of hot hardness and of hardness and fracture toughness, are at least equivalent to composite materials having a cobalt-based alloy as is routine in the prior art.
In an embodiment, the present invention provides a method for producing a composite material which includes providing a composition comprising at least one hardness carrier and a base binder alloy, and sintering the composition. The base binder alloy comprises from 66 to 93 wt.-% of nickel, from 7 to 34 wt.-% of iron, and from 0 to 9 wt.-% of cobalt, wherein the wt.-% proportions of the base binder alloy add up to 100 wt.-%.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:
FIG. 1 shows the hot hardness (HV30) curves of Example 1 and Example 2;
FIG. 2 shows the hot hardness (HV30) values of Example 5 and a comparison of the hot hardness (HV30) values of Example 1 and Example 4; and
FIG. 3 shows the fracture toughness (K 1 C) values of Example 5 and a comparison of the fracture toughness (K 1 C) values of Example 1 and Example 4.
DETAILED DESCRIPTION
It has now unexpectedly been found that particular hard metals having Ni-rich FeNi-based binder alloys are comparable in terms of hardness, hot hardness and fracture toughness (K 1 C) with hard metals bound using cobalt-based binder alloys. This is completely unexpected since these results cannot be interpolated linearly from the behavior of pure nickel as a base and the behavior of FeNi 50/50. This is possibly the reason why no hard metals bound in this way have hitherto become known.
It has now surprisingly been found that the problems arising from the prior art can be solved by the composite materials produced according to the present invention.
The present invention provides a process for producing a composite material, which comprises sintering a composition containing:
a) at least one hardness carrier, and
b) a base binder alloy comprising:
α) from 66 to 93% by weight of nickel, β) from 7 to 34% by weight of iron, and γ) from 0 to 9% by weight of cobalt,
where the proportions by weight of the base binder alloy add up to 100% by weight.
For the purposes of the present invention, the terms “hard metal” (or “cemented carbide” or “cemented hard material”) and “sintered composite material” (or “sintered composite”) are used synonymously.
In an embodiment of the present invention, the base binder alloy can, for example, have a weight ratio of iron:nickel of from 1:2 to 1:13, for example, from 1:2.5 to 1:12, for example, from 1:3 to 1:10, for example, from 1:3 to 1:9, for example, from 1:4 to 1:8, and for example, from 1:4 to 1:7.
Good results can be obtained using base binder alloys having from 66 to 90% by weight, for example, from 70 to 90% by weight, of nickel.
Base binder alloys having from 10 to 34% by weight of iron can, for example, be used. An iron content in the base binder alloy of from 10 to 30% by weight can, for example, be used.
Due to the toxic properties of cobalt, the content of cobalt in the base binder alloy should be kept as low as possible. The base binder alloy can therefore contain less than 8% by weight, for example, less than 5% by weight, and for example, less than 1% by weight, of cobalt. In an embodiment, the base binder alloy can, for example, be essentially free of other elements, for example, essentially free of metals other than nickel and iron. Nonmetals such as carbon, oxygen and nitrogen can be present in the base binder alloys and are acceptable since their contents in the sintered composite material can be desirable and can completely or partly volatilize during sintering.
For the purposes of the present invention, “essentially free” means that the element is present in an amount of less than 0.5% by weight, for example, less than 0.1% by weight, for example, less than 0.08% by weight, for example, less than 0.02% by weight, for example, less than 0.001% by weight, and for example, less than 0.005% by weight, in each case based on the total weight of the base binder alloy.
In an embodiment of the process of the present invention, the base binder alloy can, for example, contain less than 0.1% by weight, for example, less than 0.08% by weight, for example, less than 0.02% by weight, and for example, less than 0.01% by weight, of molybdenum.
A further constituent of the composition is the hardness carrier. In an embodiment of the present invention, the hardness carrier can, for example, be selected from the group consisting of carbides, nitrides, borides and carbonitrides. These can, for example, contain one or more elements of transition group 4A, 5A or 6A of the Periodic Table of Elements. The hardness carriers can be binary hardness carriers, for example, tungsten carbide, as well as ternary hardness carriers, for example, tantalum-niobium mixed carbide, titanium carbonitride or tungsten-titanium carbide, or even quaternary hardness carriers, for example, tungsten-titanium carbonitride, or tungsten-titanium-niobium-tantalum carbide.
In an embodiment of the present invention, the hardness carrier can, for example, be selected from the group consisting of titanium carbide, chromium carbide, tantalum carbide, niobium carbide, vanadium carbide, molybdenum carbide, tantalum-niobium mixed carbide, titanium carbonitride, tungsten-titanium carbide, tungsten-titanium carbonitride and tungsten carbide.
In an embodiment of the present invention, the hardness carrier can, for example, comprise at least 50% by weight of tungsten carbide, based on the total weight of the hardness carriers. In an embodiment, the hardness carrier can, for example, comprise at least 50% by weight of titanium carbonitride, based on the total weight of the hardness carriers.
The hardness carriers can, for example, be provided in pulverulent form. In an embodiment, the powders can have an average particle diameter of from 0.01 to 150 μm, for example, from 0.1 to 100 μm.
The average particle diameter is determined in accordance with ASTM B330.
The hardness carriers can, for example, have a hardness above 800 kg/mm 2 , for example, above 1000 kg/mm 2 (measured in accordance with ISO 6507, part 2).
The composition used in the process of the present invention can, for example, contain various pulverulent components. The base binder alloy based on FeNi or FeCoNi can be provided by means of prealloyed powders or powders obtained from the melt but also by means of metal powders, i.e., for example, by means of iron, nickel and optionally cobalt powders.
In an embodiment of the present invention, the hardness carrier and/or the base binder alloy can, for example, be in pulverulent form. In an embodiment, the base binder alloy can, for example, be present as an alloy powder.
The compositions used in the process of the present invention can optionally also comprise further components as additives, such as metals, for example, selected from the group consisting of rhenium, molybdenum, chromium and aluminum. Elemental tungsten or elemental carbon can, for example, be used since these are suitable for correcting the carbon content of the composite material after sintering. It is also possible, however, to add intermetallic compounds such as Ni 3 Al or chromium nitride which decomposes during sintering to the compositions to be sintered. These additives can make up to 20% by weight, for example, up to 10% by weight, of the total weight of the composition.
In an embodiment of the present invention, the composition to be used in the process of the present invention can, for example, comprise from 50% by weight to 97% by weight of hardness carriers, for example, from 60% by weight to 96% by weight, for example, from 70% by weight to 96% by weight, of hardness carriers, in each case based on the total weight of the composition.
In an embodiment of the present invention, the composition can, for example, contain from 3 to 50% by weight of the base binder alloy, for example, from 4 to 40% by weight, for example, from 4 to 30% by weight, of the base binder alloy, in each case based on the total weight of the composition.
The total weight of base binder alloy, hardness carriers and additives which may optionally be present is 100% by weight.
Sintering can, for example, be carried out at temperatures above 1000° C., for example, above 1100° C., for example, at temperatures in the range from 1150° C. to 1600° C. Sintering can, for example, be carried out in the presence of a liquid phase. The base binder alloy can, for example, be entirely or partly present in a liquid form during the sintering process.
Sintering time can vary as a function of composition. Sintering is usually carried out over a period of at least 5 minutes, for example, at least 10 minutes. Sintering time and sintering temperature are related since the time necessary for full densification can be shortened at higher sintering temperatures. The necessary sintering time and, in particular, temperature, also depends greatly on the content of base binder alloy. While, for example, the sintering temperature could be reduced down to 1250° C. at a content of the base binder alloy of 20% by weight, temperatures above 1400° C. are desirable at 5% by weight of base binder alloy. The sintering times which can be realized depend on the heat capacity of the sintering furnaces since these cannot be heated up to the sintering temperature and cooled down at any desired rate. Very short sintering times of a few minutes can, however, be realized by means of microwave sintering or SPS.
In an embodiment of the present invention, the process of the present invention comprises the following steps:
a) provision of a dispersion comprising a composition containing hardness carriers and base binder alloy, as defined above, in a solvent, b) milling of the dispersion, c) production of a powder by drying of the dispersion, d) production of compacts by pressing the powder or by extrusion of the powder with the aid of plasticizing agents, and e) sintering of the compact or of the extrudate.
In an embodiment of the present invention, the provision of the dispersion described in step a) can, for example, be carried out by adding a solvent to a pulverulent composition containing hardness carriers and base binder alloy powder. Examples of solvents include those which have a boiling point of <250° C. at 1 bar. Examples include alcohols, for example, aliphatic alcohols, for example, ethanol, and to water or mixtures thereof, for example, mixtures of water and organic solvents, such as water and alcohols. Examples also include organic solvents, for example, selected from the group consisting of ketones and hydrocarbons, for example, acetone and aliphatic hydrocarbons such as heptane and hexane.
Milling of the dispersion produced in step a) can be carried out using the milling tools with which a person skilled in the art will be familiar. Milling of the dispersion can, for example, be carried out in a ball mill or an attritor which can, for example, in each case be equipped with hard metal balls.
The dispersion can optionally also contain organic auxiliaries such as waxes, dispersants, inhibitors, adhesives or emulsifiers before the drying step.
In an embodiment of the present invention, step b) can, for example, be followed by production of a powder by drying of the dispersion. The dispersion can, for example, be spray dried or dried under reduced pressure. It has been found to be advantageous here to use solvents with a low boiling temperature which can easily be distilled off under reduced pressure as a solvent.
In an embodiment of the present invention, the dried powder from step c) can, for example, be used to produce compacts (pressed bodies) or an extrudate. Pressing of the dried powder can, for example, be carried out in tools suitable for this purpose, or isostatically.
The compact or the extrudate is subsequently sintered in step e). In an embodiment of the present invention, sintering can, for example, be carried out in the presence of a protective gas atmosphere or under reduced pressure.
In an embodiment of the present invention, the sintered composite materials can, for example, be compacted further in a separate or integrated post-compaction step under increased pressure.
In an embodiment of the present invention, pressing and sintering can, for example, be carried out simultaneously and, for example, by additional use of electric fields or currents. These can provide an elevated temperature during sintering and pressing.
The composite materials obtained by the process of the present invention are optionally subsequently ground to the required shape, with tools for cutting machining of metals usually being able to be coated further by means of chemical vapor deposition (CVD) techniques or physical vapor deposition (PVD) or combined processes.
The present invention further provides a sintered composite material obtainable by the process of the present invention.
The composite materials of the present invention comprise one or more elements from the group consisting of Fe, Ni and optionally Co as a binder alloy. Apart from this basis, the binder alloy contains elements whose content in the binder alloy cannot, in contrast to those mentioned above, be selected freely but are instead the result of solubilities and establishment of equilibria during sintering. These are, in particular, W, Mo and Cr and in smaller amounts also other carbide-forming metals (for example V, Ti, Zr, Hf, Ta, Nb) and in particular carbon, but also metals which do not form carbides, e.g. rhenium and ruthenium. The binder alloy present in the sintered hard metal is thus formed only during sintering from the base alloy and the establishment of equilibria with the other components still present in the hard metal. Such elements can also be previously present in the base alloy. However, the ultimate composition of the binder alloy is only established during sintering and subsequent cooling of the hard metal.
The binder alloy can furthermore also contain one or more elements selected from the group consisting of W, Mo, Cr, V, Ta, Nb, Ti, Zr, Hf, Re, Ru, Al, Mn, C. These elements have only a limited solubility both in the FeNi base alloy and in other base alloys and the contents thereof are established during sintering and during cooling as a result of their temperature-dependent solubility with additional dependence on the carbon content according to the principle of the solubility product of the carbides as a function of their thermodynamic stability. The sum of these elements in the binder alloy according to the present invention is therefore generally below 30% by weight, based on the total weight of the binder alloy of the sintered composite material.
In an embodiment of the present invention, the binder alloy of the sintered composite material of the present invention can, for example, comprise up to 30% by weight of one or more elements selected from the group consisting of W, Mo, Cr, V, Ta, Nb, Ti, Zr, Hf, Re, Ru, Al, Mn, B, N and C.
Selection and contents of the above elements have an influence on the properties of the binder alloy. Thus, for example, W, Cr and Mo increase the hot hardness because of their solubilities on the order of at maximum from 5 to 25% by weight. Efforts are therefore made in industrial practice to set the carbon content of the hard metal low so that the contents of these elements are as high as possible in the binder alloy without detrimental carbon-depleted phases (known as eta phases) occurring. The actual dissolved tungsten content in hard metals containing Co-based alloys is determined via magnetic saturation. If the magnetic saturation of the Co content of pure WCCo hard metals is less than 70% of that of pure cobalt, eta phases are formed. However, in industry, a safe distance from this limit is maintained for reasons of process reliability.
The sintered composite materials (hard metals) of the present invention can be ground and coated depending on the requirements of the envisaged use. They can also be inserted into tool holders, adjoined, soldered or diffusion-welded.
The hard metals of the present invention can be used for all applications where hard metals having a binder alloy based on cobalt, nickel, CoNi, FeNi or FeCoNi are used at present.
The hard metal part present after sintering and optionally after grinding or final electroeroding can advantageously have a defined geometry. This can, for example, be elongated (for example, ground out from a round sintered rod), but can also be plate-shaped for turning or milling materials such as metals, stones and composites. In all cases, the hard metal tools can, for example, have one or more coatings selected from the classes of nitrides, borides, oxides and superhard layers (for example, diamond, cubic boron nitride). These can have been applied by PVD or CVD processes or combinations or variations thereof and have their residual stress state altered after application. However, they can, for example, also be hard metal parts of any further geometry and for any further use, such as forging tools, forming tools, core drills, construction parts, knifes, peeling plates, rolls, stamping tools, pentagonal drill bits for soldering-in, mining chisels, milling tools for machining of concrete and asphalt, sliding ring seals and also any further geometries and uses.
For some applications, the hard metal can also have the surface formed during sintering, and optionally subsequently be used in coated or uncoated form.
The present invention further provides for the use of the sintered composite material of the present invention for tools or parts. The sintered composite materials of the present invention can, for example, be used for forming or comminution tools. In an embodiment of the present invention, the tool can, for example, be a tool for cutting machining of metallic tools or for forming of metal workpieces at high temperatures, for example, a tool for forging, wire drawing or rolling.
The present invention further provides for the use of a base alloy comprising:
α) from 66 to 93% by weight of nickel,
β) from 7 to 34% by weight of iron, and
γ) from 0 to 9% by weight of cobalt,
for producing a composite or a tool.
The present invention will hereinafter be illustrated by the following examples without being restricted thereto.
EXAMPLES
Example 1 (Comparative)
460 g of tungsten carbide having a particle size of 0.6 μm in accordance with ASTM B330 (type WC DS60, manufacturer: H.C. Starck GmbH, Goslar, Germany) were mixed-milled with 40 g of a commercial cobalt powder (type “efp”; manufacturer: Umicore, Belgium) in 0.57 liter of 94% ethanol at 63 rpm in a ball mill for 14 hours. 5 kg of hard metal balls were used. Two batches having different carbon contents (“high carbon” and “low carbon”) were produced so that different carbon contents and thus different magnetic saturations of the hard metals respective the cobalt-based binder alloys present were obtained after sintering.
The ethanol was separated off from the resulting suspension by distillation under reduced pressure and the hard metal powder obtained was uniaxially pressed at 150 MPa and sintered at 1420° C. The plate-shaped hard metal pieces were ground, polished and examined to determine their properties. As sintered bodies, both batches displayed neither eta phases nor carbon precipitates. The different carbon content after sintering and the associated different tungsten content in the binder metal alloy is the result of mass transfer during sintering. The binder metal alloy thus consists of cobalt as basis with proportions of tungsten and possibly carbon.
TABLE 1
Carbon
“low carbon”
“high carbon”
Hardness (HV 30) (kg/mm 2 )
1626
1597
Magnetic saturation (G · cm 3 /g)
123
132
Porosity (ISO 4505)
<A02B00C00
<A02<B02C00
Fracture toughness (MPa · m 1/2 )
9.3
9.5
Density (g/cm 3 )
14.78
14.74
In both cases, room temperature hardness was determined as Vickers hardness HV30 in accordance with ISO 3878 as well as hot hardness was determined at selected temperatures up to 800° C. under protective gas in a hardness testing apparatus ( FIG. 1 ). For this purpose, both hard metal batches were sintered again and the pieces obtained had a density of 14.79 g/cm 3 and a magnetic saturation of 127 (+/−1) Gcm 3 /g, corresponding to 78.5% of the theoretically possible magnetic saturation in the case of the “low carbon” variant. The “high carbon” variant had, on average, a density of 14.75 (+/−0.01) g/cm 3 and a magnetic saturation of 133 (+/−1) Gcm 3 /g, corresponding to 82% of the theoretical saturation.
Fracture toughness K 1 C was determined according to the formula of Shetty:
K 1 C= 0.0028×9.81×( HV 30/ R ) 1/2 (in MPa m 1/2 ).
R=crack resistance=30/sum of the length of the cracks (in μm)×1000.
HV30=Vickers hardness under a load of 30 kg (kg/mm 2 ).
Example 2 (Inventive)
Example 1 was repeated, but in this case the two batches consisted of 461.5 g of tungsten carbide having a particle size of 0.6 μm and the binder metal basis consisted of 38.5 g of an alloy powder containing 15% by weight of Fe and 85% by weight of Ni. The carbon content of these hard metal batches was set by addition of carbon black (5.55% for the “low carbon” variant and 5.65% for the “high carbon” variant) so that neither eta phases nor carbon precipitates were obtained after sintering at 1440° C. for 60 minutes. The different carbon content after sintering and the associated different tungsten content in the binder metal alloy is the result of mass transfer during sintering. The binder metal alloy thus consists of iron and nickel in a weight ratio of 1:5.7 as basis, alloyed with proportions of tungsten and possibly carbon.
The results after sintering at 1420° C. for 60 minutes and metallographic examination are shown in Table 2 below:
TABLE 2
Carbon
“low carbon”
“high carbon”
Hardness (HV30)
1574
1591
Magnetic saturation (G · cm 3 /g)
51
66.8
Porosity (ISO 4505)
<A02B00C00
<A02B00C00
Fracture toughness (MPa · m 1/2 )
10.2
11
Density (g/cm 3 )
14.83
14.81
The room temperature hardness values are somewhat lower than those from Example 1, which is due to the low hardness and higher plasticity of the austenitic base alloy. However, the fracture toughnesses are, even taking account of the somewhat lower hardnesses, at least on the same level as in Example 1. Increasing carbon values in the sintered body correlate with increasing magnetic saturation and, owing to the low density of graphite, with decreasing density.
The hot hardnesses were determined as before (for results, see FIG. 1 ). For this purpose, fresh sintered bodies were produced from the hard metal batches available. The “low carbon” variant had here achieved a density of 14.81 g/cm 3 and a magnetic saturation of from 54 to 55 Gcm 3 /g. The “high carbon” variant gave densities in the range from 14.77 to 14.79 g/m 3 and magnetic saturations in the range from 70.5 to 72.5 Gcm 3 /g. The boundary to the eta phase is below 51 Gcm 3 /g, and the boundary to carbon precipitation is about 75 Gcm 3 /g. The sintered pieces were thus free of eta phase and carbon precipitates. The two sintered batches were thus in the middle and high range, but not in the low range, for the carbon content, which would have been advantageous for a high hot hardness.
FIG. 1 shows the hot hardness curves and demonstrates that the hard metals according to the present invention with the base binder alloy based on FeNi are in the range of the hot hardness of hard metals bound using a cobalt basis despite the medium and high carbon content, have the same proportion by volume of base binder alloy and are in the lower half of the carbon window and thus have good hot hardnesses. The results obtained in this way for the hot hardness are thus determined by the nature of the base binder alloy. It should be emphasized that this effect occurs even though the starting level of the hardness is lower compared to Example 1.
It can also be seen that in the case of this base binder alloy, the properties K 1 C and hot hardness are advantageously only slightly dependent on the carbon content of the hard metal.
The room temperature hardness values in the hot hardness curve are not identical with those from the above tables of Examples 1 and 2 since they were determined by means of a different hardnesses testing apparatus, namely the hot hardness tester.
Example 3 (Comparative)
In a manner analogous to Example 2, various batches were produced from a WC (0.6 μm particle size and 7.5% of a FeCoNi alloy powder (Ampersint® MAP A6050, manufacturer: H.C. Starck GmbH, Germany, composition: Fe 40%, Co 20%, Ni 40%) as binder metal basis. The proportion by volume of the base binder alloy corresponds to that of Example 1.
The hard metals obtained, which contained neither eta phase nor carbon precipitates, had an HV30 in the range from 1626 to 1648. The K 1 C values were mostly in the range from 8.5 to 8.9 MPa m 1/2 . Only in a very narrow range at high carbon contents at the boundary to the region of carbon precipitation were values of from 9.3 to 9.5 found for the K 1 C.
The inferiority of the FeCoNi-based alloy in terms of the hot hardness has already been publicized in WO 2010/046224 (there, Example 1 and FIG. 1 ).
In summary, hard metals having a FeCoNi 40/20/40 base binder are inferior in terms of K 1 C and hot hardness to hard metals bound by means of cobalt as basis for the binder alloy.
Example 4 (Comparative)
In a manner analogous to Example 1, hard metals were produced using 7.4% by weight of a FeNi 50/50 alloy powder (Ampersint® MAP A5000, manufacturer: H.C. Starck GmbH, Germany) as base binder alloy. The proportion by volume of the base binder alloy corresponds to that in Example 1. The hard metals obtained, which were free of eta phases or carbon precipitates, had HV30 values in the range from 1619 to 1636. The K 1 C values were in the range from 8.3 to 8.6 MPa m 1/2 . FIG. 2 shows that the hot hardness values correspond to those of a corresponding hard metal with cobalt as base binder alloy.
Hard metals with a binder alloy based on FeNi 50/50 thus have at least equal hot hardnesses but display comparatively low K 1 C values, so that hard metals having such a binder basis cannot be universally used ( FIG. 3 ). Although hard metals having this base binder alloy can thus be used for turning of metals, they cannot be used for milling because of their low K 1 C value since the mechanical shock resistance is insufficient.
Example 5 (Partly Inventive—as Indicated by “*”)
In a manner analogous to Example 1, hard metals having different Fe/Ni ratios in the range from 35/65 to 0/100 were produced. In all cases, the proportion by volume of the base binder alloy corresponded to that in Example 1. The Fe:Ni ratio in the base binder alloy was varied by using FeNi 50/50 as in Example 4 (Fe:Ni ratio 1:1) and a Ni powder (manufacturer: Vale-Inco, GB, type 255) in such amounts that the desired Fe:Ni ratio was obtained and the proportion by volume of Example 1 was attained. Additional variation of the carbon content in the batches ensured that all hard metals were free of carbon precipitates and also of eta phases after sintering. All hard metals were sintered together at 1420° C. for 60 minutes.
Table 3 below summarizes the results obtained in this way:
TABLE 3
Magnetic
HV30
K1C
Density
saturation
Fe/Ni ratio
(kg/mm 2 )
(MPa m 1/2 )
(g/cm 3 )
(G cm 3 /g)
35/65*
1618
9.2
14.75
102
25/75*
1626
9.3
14.67
94.7
15/85*
1608
9.4
14.74
98.4
10/90*
1618
11.3
14.84
42.3
5/95
1541
10.7
14.79
38.2
0/100
1478
12.4
14.81
42.7
FIGS. 2 and 3 show the results of Example 5 and compare Examples 1 and 4.
It is evident that the hardness decreases only very slightly with increasing nickel contents, while the K 1 C increases slightly and at about 65% of Ni reaches the values of the comparative hard metals from Example 1. This also applies to the K 1 C, for which values above 10 have a tendency to larger relative errors. The K 1 C values were calculated from the crack lengths according to the formula of Shetty. Since large relative errors occur when reading off the crack length under the microscope in the case of very short crack lengths but short crack lengths yield high K 1 C values, the relative error in the K 1 C increases steadily with the measured value itself, as can readily been seen in the figure.
Surprisingly, however, the hardness barely decreases from 50% of Ni to unexpectedly high Ni contents of 90%. The hardness surprisingly remains virtually constant up to values of 90% of Ni, and then decreases suddenly. It can be interpolated that the required hardness level given by the relatively low hardness value of comparative Example 1 is achieved at Ni contents from up to 93%.
The combination of properties of the WCCo hard metals from Example 1 are achieved at a Fe/Ni ratio in the range from about 34/66 (corresponding to about 1:2) to 7/93 (corresponding to about 1:13); below this, the K 1 C decreases and above this, the hardness decreases very greatly and sharply.
The present invention is not limited to embodiments described herein; reference should be had to the appended claims.
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A method for producing a composite material includes providing a composition comprising at least one hardness carrier and a base binder alloy, and sintering the composition. The base binder alloy comprises from 66 to 93 wt.-% of nickel, from 7 to 34 wt.-% of iron, and from 0 to 9 wt.-% of cobalt, wherein the wt.-% proportions of the base binder alloy add up to 100 wt.-%.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to markers, and in particular to a terrestrial marker post adapted for locating buried utility lines and the like, and a method and apparatus for manufacturing same.
2. Description of the Prior Art
Marker posts are commonly used for marking the locations of various underground objects. For example, utility lines are often buried. In many locations utility lines are required to be placed underground for aesthetic reasons.
In recent years fiber-optic cable networks have been installed in many parts of the country. A common installation procedure involves trenching or boring underground and placing the fiber-optic cables within protective plastic conduit. The fiber-optic cables have many advantages for telecommunications, including the ability to efficiently transmit large amounts of data. However, the potential earnings losses associated with an inoperative fiber-optic cable can be very large, because relatively high revenues are commonly generated from their transfer of correspondingly large amounts of data for telecommunications customers.
Excavating equipment and operations pose significant threats to buried utility lines, including fiber-optic cables. Natural gas pipelines, for example, pose an explosion risk. Electrical power lines have attendant risks of damage and injuries related to electrical power. Accidentally severing a buried fiber-optic cable can subject an excavation contractor to significant liability for interrupted service.
In order to control such risks, utility companies and service providers have marked the locations of their underground lines and provided information regarding same, such as toll-free numbers, which excavators are encouraged to “call before digging”. A common pre-existing type of marker includes a length of plastic pipe with one end embedded in the ground and the other end mounting a cap. The cap can have printed thereon warning information, and can be color-coded for the type of buried utility, e.g.: blue—water; yellow—natural gas; red—electric; orange (white)—fiber-optic, etc. Such utility markers tend to be relatively effective and are widely recognized. Another advantage is that they are relatively easy to install, but unfortunately many of the prior art designs were easily removed. For example, the surrounding soil can often be loosened by manipulating the above-ground portion of a marker post. The prior art marker posts were thus susceptible to vandalism, theft, etc. A previous solution to this problem involved extending a peg through the embedded portion of the marker post and into the surrounding soil for pullout resistance. However, the pegs and their receivers represented additional components and installation steps, thus adding to the installed costs of the marker posts. Moreover, installing the pegs was sometimes overlooked whereby the marker posts were unprotected.
Heretofore there has not been available a marker post and manufacturing method with the advantages and features of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical, cross-sectional view of a marker post embodying the present invention.
FIG. 2 is an enlarged, fragmentary, cross-sectional view thereof, taken generally within circle 2 in FIG. 1 .
FIG. 3 is a further enlarged, fragmentary, cross-sectional view thereof, taken generally within circle 3 in FIG. 2 .
FIG. 4 is a perspective view of a warming tank used in the practice of the method of the present invention.
FIG. 5 a is a top plan view of a barrel holder used in the practice of the method of the present invention.
FIG. 5 b is a fragmentary, top plan view of the barrel holder, particularly showing a mandrel plug thereof advancing into the lower end of the tubular barrel.
FIG. 5 c is a fragmentary, top plan view of the barrel holder, particularly the mandrel plug fully advanced into the barrel lower end.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Introduction and Environment.
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.
Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, “up” and “down” refer to the invention as oriented in FIG. 1 . The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of a similar import.
Referring to the drawings in more detail, the reference 2 generally designates a marker post embodying the present invention. Without limitation on the generality of useful applications of the invention, the marker post 2 is shown over a buried fiber-optic cable 4 , which is run through buried plastic conduit. The marker post 2 , being hollow, is optionally adapted to receive a length of conduit 6 containing conductors 8 , which can be capped or temporarily terminated (e.g., with wire nuts 10 as shown) for future splicing in connection with a future transformer location or an expansion or extension of utility services.
II. Marker Post 2 .
The marker post 2 includes a tubular barrel 12 with a bore 14 extending between and open at upper and lower ends 16 , 18 . The tubular barrel 12 can comprise any suitable thermoplastic material, such as polyethylene, and is formed with a sidewall 20 having interior and exterior surfaces 20 a, b.
An annular flange assembly 22 is formed at the tubular barrel lower end 18 and includes an extension portion projecting radially outwardly from the tubular barrel lower end 18 . As shown in FIG. 3, in cross section the extension portion 24 curves through slightly more than 180 degrees, and displays a concave configuration. An annular return portion of the flange assembly 22 extends upwardly and radially inwardly from the extension portion 24 , and terminates at a flange assembly rim 28 . An upwardly-open, annular channel or groove 30 is formed between the tubular barrel outer surface 20 a and the return portion 26 , and is upwardly-open at an annular channel clearance 32 . The channel 30 is closed at its lower end by the flange assembly extension portion 24 . The configurations of the flange assembly 22 and the channel 30 formed thereby tend to resist pull-out of the implanted marker post 2 .
A cap 34 is provided for conveying information, which can be printed thereon and typically comprises a warning such as “WARNING BURIED FIBER OPTIC CABLE IN THIS VICINITY”, together with graphic warnings, contact information such as toll-free numbers, which can be called for additional information, etc. The cap 34 has a closed upper end 36 , which can generally be configured like a hemisphere, and an open lower end 38 . The cap 34 telescopically receives through its open lower end 38 the tubular barrel 12 adjacent to its upper end 16 . The cap 34 can comprise any suitable material, such as a suitable thermoplastic adapted to receive printing thereon by any suitable technique, such as silkscreening.
In operation, the marker post is adapted for embedding in soil to a sufficient depth (generally about 1 to 2 feet), as shown in FIG. 1 . Power augers, post hole diggers and other suitable digging tools can be used for digging a hole 40 to receive the marker post 2 . The hole 40 is preferably sized to accommodate the flange assembly 22 , i.e. slightly oversized with respect to the tubular barrel 12 . The concave configuration of the flange assembly 22 facilitates inserting the marker post 2 . Moreover, this concave configuration, with the corresponding curved cross-sectional configuration, provides considerable structural strength for the flange assembly 22 . The marker post 2 is inserted into the hole 40 to refusal, whereat a substantial portion of its length is left aboveground. The surrounding soil 42 is then backfilled around the tubular barrel 12 , and occupies the channel 30 for engagement by the flange assembly 22 whereby the marker post 2 effectively resists pullout. The upwardly-open configuration of the channel 30 tends to resist pullout throughout the embedded length of the tubular barrel 12 . Thus, even lifting the marker post 2 somewhat out of the hole 40 will not cause it to release. Rather, the configuration of the flange is likely to cause the marker post 2 to continue to resist pullout, thus hopefully discouraging its unauthorized removal.
III. Manufacturing Method and Apparatus.
Without limitation on the generality of useful methods and apparatus for manufacturing the marking post 2 , an exemplary method is described using a manufacturing apparatus 52 , as shown in FIGS. 4, 5 a , 5 b and 5 c.
FIG. 4 shows a warming tank 54 with an open-top vessel 56 mounting a grid 58 , which provides multiple barrel receivers 58 a adapted for maintaining the tubular barrels 12 in upright positions. Lower portions of the tubular barrels 12 are immersed in heat transfer liquid 60 , which is heated by a thermostat-controlled heater 62 mounted on the vessel 56 . The heat transfer liquid 60 can include glycol or some other suitable component to raise its boiling temperature. The polyethylene tubular barrels 12 soften and become pliable at about 165 degrees Fahrenheit, so the heat transfer liquid 60 temperature can be maintained in the range of approximately 185 degrees to 200 degrees Fahrenheit for effective preheating of the tubular barrels 12 to a softened, pliable temperature.
FIGS. 5 a-c show formation of the flange assembly 22 on a clamping barrel holder 64 , which includes first and second ends 66 , 68 with respective split sleeves 70 each comprising a fixed or lower half 72 and a movable or upper half 74 . Each upper sleeve half 74 is hingedly mounted on a respective lower sleeve half 72 and is raised and lowered with respect thereto between open and closed positions by a handle 75 . Latching mechanisms 76 are provided for locking the respective sleeves 70 in their closed positions.
A mandrel assembly 78 is located at the barrel holder second end 68 and includes a slide subassembly 80 slidably movable between extended and retracted positions (FIGS. 5 a and 5 c respectively) by a linear actuator, comprising a piston-and-cylinder unit 81 . Without limitation on the generality of useful linear actuators, a double-acting pneumatic piston-and-cylinder unit is shown and is adapted for connection to a compressed air source 77 through a three-way valve 79 . The valve 79 can including a lever for manual operation, a foot pedal for foot operation, a solenoid for electrical operation, etc. The linear actuator 82 is shown in its retracted position in FIG. 5 a , with a mandrel plug 82 thereof generally aligned with the barrel bore 14 and positioned in close proximity to the barrel lower end 18 .
The mandrel plug 82 is generally cylindrical with a distal end 83 chamfered at 83 a to facilitate insertion into the barrel bore 14 and a proximate end 84 mounted on a mandrel base 85 . The mandrel plug 82 has an annular, convex forming rim 86 (FIGS. 5 b , 5 c ) located at the junction between its proximate end 84 and the base 85 . The mandrel plug forming rim 86 is adapted for engaging the softened barrel lower end 18 and curving same through an angle of slightly more than 180 degrees, e.g., in the range of about 190 degrees to 220 degrees. As shown in FIG. 5 c , the barrel lower end 18 generally doubles back on itself into engagement with the split sleeve 70 , thus forming the flange assembly 22 . In this position the slide subassembly 80 and the piston-and-cylinder unit 81 driving same are in their fully-extended positions. Retracting the piston-and-cylinder unit 82 retracts the slide subassembly 80 and withdraws the mandrel plug 82 whereby the formed barrel 12 can be removed.
It is to be understood that while certain forms 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 method of manufacturing a marker post includes the steps of preheating a tubular barrel adjacent to a lower end thereof to soften same and deforming the tubular barrel lower end to form a flange assembly. The pre-softened tubular barrel is received in a barrel holder. A mandrel assembly is reciprocated into and out of engagement with the barrel lower end. The mandrel assembly reshapes the barrel lower end to form the flange assembly.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains generally to modular electrical systems used in modular wall systems, and, more particularly, relates to a distribution block for distributing electrical current to a plurality of components attached to the distribution block.
2. Description of the Related Art
Modular wall systems are used in many situations to construct temporary, or at least rearrangeable office configurations. With the proliferation of computer work stations, and the decreasing costs for obtaining and operating various office equipment including printers, scanners, fax machines and the like, the installations of such equipment have increased, and there is an ever increasing need for electrical, communication and data transmission circuits in each defined work space. Rearrangement of the work space defined by the panels, and/or rearrangement of the equipment within the work space can result in the need to relocate the various receptacles to avoid unsightly and unsafe dependence on extension cords.
To meet the need for relocatable and expandable electrical, data and communication circuitry in modular wall systems, it is known to provide a wire race in the modular wall, commonly near the bottom thereof. Plugable circuit components may include distribution, jumper and receptacle elements that can be combined and configured to achieve the desired outlet locations.
As needs have increased, it has become more common to require receptacles on both sides of the modular wall. Separate distribution components can be used, but this requires a relatively large wire race, and can result in an undesirable amount of wires or cables in the wire race. Alternatively, components can be used to service both sides of a wall panel. Unfortunately, wall panels are provided in a variety of different thicknesses, and it has been necessary to stock specialized components for each wall width if single components are to be used to service both sides of the wall. Supply costs and storage space are increased by each different wall thickness being used.
What is needed in the art is a distribution terminal block that can accommodate both sides of a modular wall, and is adjustable for walls of different thicknesses.
SUMMARY OF THE INVENTION
The present invention provides an electrical distribution block that is adjustable in width, to accommodate walls of different thickness.
The invention comprises, in one form thereof, an electrical distribution block with a first connector assembly having a first plurality of electrical branch connectors and a first bridge portion including first bridge connectors electrically connected to the first plurality of electrical branch connectors. A second connector assembly has a second plurality of branch connectors and a second bridge portion including second bridge connectors electrically connected to the second plurality of electrical branch connectors. The bridge connectors of the first bridge portion and the bridge connectors of the second bridge portion are adapted for direct electrical connection to each other along a variable length establishing a variable spacing between the first connector assembly branch connectors and the second connector assembly branch connectors.
In another form thereof, the invention provides an electrical distribution block with a first T-shaped connector assembly having first and second branch connectors extending in opposite directions relative to each other, and first bridge connectors extending perpendicular thereto. A second T-shaped connector assembly has third and fourth branch connectors extending in opposite directions relative to each other, and second bridge connectors extending perpendicular thereto. The first and second bridge connectors are adapted for telescopic engagement with each other.
In a further form thereof, the invention provides an electrical distribution block with first and second oppositely directed branch connectors; third and fourth oppositely directed branch connectors disposed in parallel, spaced relation to the first and second branch connectors; and an electrical bridge disposed between and electrically connecting the first and second branch connectors with the third and fourth branch connectors.
An advantage of the present invention is providing a distribution block that can be connected in a distribution line to accommodate several receptacles, and can be coupled with a variety of modular components.
Another advantage of the invention is providing a distribution block which is adjustable to fit in modular walls of different thickness, to provide receptacle sites along opposite wall surfaces of a modular wall panel.
A further advantage of the invention is providing a distribution block having a variety of applications, thereby reducing the number of parts required in modular electrical power distribution systems.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent, and the invention will be better understood by reference to the following description of an embodiment of the invention, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an exploded perspective view of an electrical distribution block according to the present invention;
FIG. 2 is a perspective view, partially broken away, of the distribution block of FIG. 1, shown in an assembled condition from the side opposite the side shown in FIG. 1; and
FIG. 3 is a perspective view of a modular electrical distribution system in which distribution blocks of the present invention are used.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now more specifically to the drawings, and to FIG. 1 in particular, an electrical distribution block 10 of the present invention is shown. Distribution block 10 includes a first connector assembly 12 and a second connector assembly 14 , each adapted for connection to each other to form an electrically coupled structure having four sites for connecting to other components of a modular electrical distribution system 16 , described in greater detail hereinafter, illustrated in a modular wall panel 18 shown in phantom lines in FIG. 3 . First connector assembly 12 and second connector assembly 14 are joined to each other through first and second bridge portions 20 and 22 .
First connector assembly 12 is a substantially T-shaped structure, and includes a group of first branch connectors 30 and a group of second branch connectors 32 disposed and arranged in substantially opposite direction. First and second branch connectors 30 and 32 are configured for connection to and with other components of electrical distribution system 16 to be described hereinafter.
First connector assembly 12 , and specifically first bridge portion 20 thereof, includes first bridge connectors 34 electrically coupled to first and second branch connectors 30 and 32 . Bridge connectors 34 are disposed perpendicular to first and second branch connectors 30 and 32 . As those skilled in the art will readily understand, first and second branch connectors 30 and 32 and bridge connectors 34 may be formed as a series of stacked, individual terminals A, B, C, D, E, F, G and H, each such terminal being essentially T-shaped and having ends each corresponding to one of the branch connectors 30 and 32 and bridge connector 34 . Thus, terminal A has first branch connector terminal end 30 A, second branch connector terminal end 32 A and bridge connector terminal end 34 A. The respective first and second branch connector ends 30 B- 30 H and 32 B- 32 H and bridge connectors 34 B-H are also shown. In various applications of the present invention, a distribution block 10 may include more or fewer first branch connectors 30 , second branch connectors 32 and bridge connectors 34 than as shown.
A generally T-shaped housing 36 is provided and includes first and second branch connector housings 40 and 42 surrounding first and second branch connectors 30 and 32 , respectively, and a bridge connector housing 44 surrounding bridge connectors 34 .
Second connector assembly 14 is also a substantially T-shaped structure, and includes a group of third branch connectors 50 and a group of fourth branch connectors 52 disposed and arranged in substantially opposite directions. Third and fourth branch connectors 50 and 52 also are configured for connection to and with other components of electrical system 16 to be described hereinafter.
Second connector assembly 14 , and more specifically second bridge portion 22 thereof, further includes second bridge connectors 54 electrically coupled to third and fourth branch connectors 50 and 52 . Bridge connectors 54 are disposed substantially perpendicular to third and fourth branch connectors 50 and 52 . Third and fourth branch connectors 50 and 52 and second bridge connectors 54 likewise may be formed as a series of stacked individual terminals I, J, K, L, M, N, 0 and P. Each terminal is essentially T-shaped and includes third and fourth branch connector ends 50 I-P and 52 I-P, respectively, and bridge connector ends 54 I-P. In various applications of the present invention, a distribution block 10 may include more or fewer third branch connectors 50 , fourth branch connectors 52 and second bridge connectors 54 than as shown.
A generally T-shaped housing 56 is provided for second connector assembly 14 and includes third and fourth branch connector housings 60 and 62 surrounding third and fourth branch connectors 50 and 52 , respectively, and a second bridge connector housing 64 surrounding bridge connectors 54 .
First connector assembly 12 and second connector assembly 14 are complementary halves forming distribution block 10 . First connector assembly 12 and second connector assembly 14 join to each other through first and second bridge connectors 34 and 54 and first and second bridge connector housings 44 and 64 of first and second bridge portions 20 and 22 . First bridge connectors 34 are formed as male terminals, comprising an elongated flat blade. Second bridge connectors 54 are formed as female terminals having upper and lower elements biased toward each other at the outer ends thereof. First bridge connectors 34 are received in second bridge connectors 54 and provide electrical conductivity therethrough. Electrical contact can be made anywhere along the lengths of first bridge connectors 34 . It should be understood that first and second bridge connectors 34 and 54 can be of other shapes and forms, and each may include a combination of male and female terminals.
First bridge connector housing 44 is provided sufficiently smaller in cross-section to be received in second bridge connector housing 64 . As thus configured, first and second bridge connectors 34 and 54 and first and second bridge connector housings 44 and 64 are telescopically engaged one with the other such that they can be overlappingly engaged to a greater or lesser length as desired. In doing so, first and second branch connectors 30 and 32 , which are oppositely directed relative to each other and substantially parallel to the similarly oppositely directed third and fourth branch connectors 50 and 52 , can be selectively arranged spaced a selectively greater or lesser distance from third and fourth branch connectors 50 and 52 . In this manner, connector block 10 can be adjusted to fit in modular wall panels 18 of different thickness, and can function to provide electrical service to both sides of modular wall panel 18 .
First, second, third and fourth branch connectors 30 , 32 , 50 and 52 , respectively, are each similarly configured to be electrically connected to other components of modular electrical distribution system 16 , and a plurality of distribution blocks 10 can be used in configuring electrical distribution system 16 as desired.
An example of the manner in which several distribution blocks 10 can be used is illustrated in FIG. 3 . Assuming modular wall panel 18 is a first section of a wall system, a power entry cable 70 is provided from an electrical power source (not shown) that may be an electrical breaker box or the like. With a first distribution block 10 oriented to have first and third branch connectors 30 and 50 facing toward power entry cable 70 , an end connector 72 on cable 70 can be connected to either first branch connectors 30 or third branch connectors 50 . Electrical current is thus available at second and fourth branch connectors 32 and 52 and the other of first and third branch connectors 30 or 50 that is not connected to connector 72 of cable 70 . Various combinations of receptacles 74 and jumper cables 76 having similar end connectors 72 , can be used with additional distribution blocks 10 , to configure electrical system 16 as desired, with receptacles provided in sufficient number and at convenient locations in modular wall panel 18 . By adjusting the telescopic overlap of first and second bridge connectors 34 and 54 and the telescopic overlap of first and second bridge connector housings 44 and 64 , first and second branch connectors 30 and 32 can be spaced a selected distance from third and fourth branch connectors 50 and 52 so that receptacles 74 connected on opposite sides of distribution block 10 are properly aligned with opposite faces of modular wall 18 .
Those skilled in the art will recognize the manner in which receptacles 74 and jumper cables 76 can be connected to each other and/or to one or more terminal blocks 10 to provide a series of receptacles exposed on the opposite faces of modular wall panel 18 .
The present invention provides a distribution block that is adjustable to fit within walls of different thickness. The number of different parts required for modular electrical systems in modular walls is reduced.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
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An electrical distribution block suitable for use in modular wall systems of various thicknesses. The electrical distribution block includes branch connectors spaced from each other by an electrically conductive bridge having a telescopic engagement such that a spacing between the branch connectors can be selectively controlled for use in modular walls of different thickness.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This application is a Continuation of U.S. application Ser. No. 10/851,481, filed on May 24, 2004, incorporated herein by reference in its entirety, which is an application claiming the benefit of U.S. Provisional Application Ser. No. 60/472,407, filed on May 22, 2003, the entire contents of which are incorporated by reference herein.
FIELD OF THE INVENTION
This invention pertains generally to prostacyclin analogs and methods for their use in promoting vasodilation, inhibiting platelet aggregation and thrombus formation, stimulating thrombolysis, inhibiting cell proliferation (including vascular remodeling), providing cytoprotection, preventing atherogenesis and inducing angiogenesis. Through these prostacyclin-mimetic mechanisms, the compounds of the present invention may be used in the treatment of/for: pulmonary hypertension, ischemic diseases (e.g., peripheral vascular disease, Raynaud's phenomenon, Scleroderma, myocardial ischemia, ischemic stroke, renal insufficiency), heart failure (including congestive heart failure), conditions requiring anticoagulation (e.g., post MI, post cardiac surgery), thrombotic microangiopathy, extracorporeal circulation, central retinal vein occlusion, atherosclerosis, inflammatory diseases (e.g., COPD, psoriasis), hypertension (e.g., preeclampsia), reproduction and parturition, cancer or other conditions of unregulated cell growth, cell/tissue preservation and other emerging therapeutic areas where prostacyclin treatment appears to have a beneficial role. These compounds may also demonstrate additive or synergistic benefit in combination with other cardiovascular agents (e.g., calcium channel blockers, phosphodiesterase inhibitors, endothelial antagonists, antiplatelet agents).
BACKGROUND OF THE INVENTION
Many valuable pharmacologically active compounds cannot be effectively administered orally for various reasons and are generally administered via intravenous or intramuscular routes. These routes of administration generally require intervention by a physician or other health care professional, and can entail considerable discomfort as well as potential local trauma to the patient.
One example of such a compound is treprostinil, a chemically stable analog of prostacyclin. Although treprostinil sodium (Remodulin®) is approved by the Food and Drug Administration (FDA) for subcutaneous administration, treprostinil as the free acid has an absolute oral bioavailability of less than 10%. Accordingly, there is clinical interest in providing treprostinil orally.
Thus, there is a need for a safe and effective method for increasing the systemic availability of treprostinil via administration of treprostinil or treprostinil analogs.
SUMMARY OF THE INVENTION
In one embodiment, the present invention provides a compound having structure I:
wherein,
R 1 is independently selected from the group consisting of H, substituted and unsubstituted benzyl groups, and groups wherein OR 1 are substituted or unsubstituted glycolamide esters;
R 2 and R 3 may be the same or different and are independently selected from the group consisting of H, phosphate and groups wherein OR 2 and OR 3 form esters of amino acids or proteins, with the proviso that all of R 1 , R 2 and R 3 are not H;
an enantiomer of the compound;
and pharmaceutically acceptable salts of the compound and polymorphs.
In some of these embodiments, R 1 is a substituted or unsubstituted benzyl group, such as CH 2 C 6 H 5 . In other embodiments, OR 1 is a substituted or unsubstituted glycolamide ester, R 1 is —CH 2 CONR 4 R 5 , R 4 and R 5 may be the same or different and are independently selected from the group consisting of H, OH, substituted and unsubstituted alkyl groups, —(CH 2 ) m CH 3 , —CH 2 OH, and —CH 2 (CH 2 ) n OH, with the proviso that m is 0, 1, 2, 3 or 4, and n is 0, 1, 2, 3 or 4. In certain of these embodiments one or both of R 4 and R 5 are independently selected from the group consisting of H, —OH, —CH 3 , or —CH 2 CH 2 OH. In any of the previously discussed embodiments, one or both of R 2 and R 3 can be H. In some enantiomers of the compound R 1 =R 2 =R 3 =H, or R 2 =R 3 =H and R 1 =valinyl amide.
In still further embodiments of the present compounds R 2 and R 3 are independently selected from phosphate and groups wherein OR 2 and OR 3 are esters of amino acids, dipeptides, esters of tripeptides and esters of tetrapeptides. In some compounds only one of R 2 or R 3 is a phosphate group. In other compounds R 2 and R 3 are independently selected from groups wherein OR 2 and OR 3 are esters of amino acids, such as esters of glycine or alanine. In any of the above embodiments, one of R 2 and R 3 are H. In certain of the present compounds, the oral bioavailability of the compound is greater than the oral bioavailability of treprostinil, such as at least 50% or 100% greater than the oral bioavailability of treprostinil. The above compounds can further comprise an inhibitor of p-glycoprotein transport. Any of these compounds can also further comprise a pharmaceutically acceptable excipient.
The present invention also provides a method of using the above compounds therapeutically of/for: pulmonary hypertension, ischemic diseases, heart failure, conditions requiring anticoagulation, thrombotic microangiopathy, extracorporeal circulation, central retinal vein occlusion, atherosclerosis, inflammatory diseases, hypertension, reproduction and parturition, cancer or other conditions of unregulated cell growth, cell/tissue preservation and other emerging therapeutic areas where prostacyclin treatment appears to have a beneficial role. A preferred embodiment is a method of treating pulmonary hypertension and/or peripheral vascular disease in a subject comprising orally administering a pharmaceutically effective amount of a compound of structure II:
wherein,
R 1 is independently selected from the group consisting of H, substituted and unsubstituted alkyl groups, arylalkyl groups and groups wherein OR 1 form a substituted or unsubstituted glycolamide ester;
R 2 and R 3 may be the same or different and are independently selected from the group consisting of H, phosphate and groups wherein OR 2 and OR 3 form esters of amino acids or proteins, with the proviso that all of R 1 , R 2 and R 3 are not H;
an enantiomer of the compound; and
a pharmaceutically acceptable salt or polymorph of the compound.
In some of these methods, when OR 1 forms a substituted or unsubstituted glycolamide ester, R 1 is —CH 2 CONR 4 R 5 , wherein R 4 and R 5 may be the same or different and are independently selected from the group consisting of H, OH, substituted and unsubstituted alkyl groups, —(CH 2 ) m CH 3 , —CH 2 OH, and —CH 2 (CH 2 ) n OH, with the proviso that m is 0, 1, 2, 3 or 4, and n is 0, 1, 2, 3 or 4. In other methods R 1 is a C 1 -C 4 alkyl group, such as methyl, ethyl, propyl or butyl. In the disclosed methods, R 1 can also be a substituted or unsubstituted benzyl group. In other methods, R 1 can be —CH 3 or —CH 2 C 6 H 5 . In still other methods R 4 and R 5 are the same or different and are independently selected from the group consisting of H, OH, —CH 3 , and —CH 2 CH 2 OH. In yet other methods, one or both of R 2 and R 3 are H. Alternatively, one or both of R 2 and R 3 are not H and R 2 and R 3 are independently selected from phosphate and groups wherein OR 2 and OR 3 are esters of amino acids, dipeptides, esters of tripeptides and esters of tetrapeptides. In some methods, only one of R 2 or R 3 is a phosphate group. In additional methods, R 2 and R 3 are independently selected from groups wherein OR 2 and OR 3 are esters of amino acids, such as esters of glycine or alanine. In further methods one of R 1 and R 2 is H. In some methods, enantiomers of the compound where R 1 =R 2 =R 3 =H, or R 2 =R 3 =H and R 1 =valinyl amide are used.
In various methods the oral bioavailability of the compound is greater than the oral bioavailability of treprostinil, such as at least 50% or 100% greater than the oral bioavailability of treprostinil. The present methods can also comprise administering pharmaceutically effective amount of a p-glycoprotein inhibitor, simultaneously, sequentially, or prior to administration of the compound of structure II. In some embodiments the p-glycoprotein inhibitor is administered orally or intravenously. The disclosed methods can be used to treat pulmonary hypertension.
The present invention also provides a method of increasing the oral bioavailability of treprostinil or pharmaceutically acceptable salt thereof, comprising administering a pharmaceutically effective amount of a p-glycoprotein inhibitor and orally administering a pharmaceutically effective amount of treprostinil to a subject. In certain of these embodiments the p-glycoprotein inhibitor is administered prior to or simultaneously with the treprostinil. The route of the p-glycoprotein inhibitor administration can vary, such as orally or intravenously. The present invention also provides a composition comprising treprostinil or a pharmaceutically acceptable salt thereof and a p-glycoprotein inhibitor.
The present compound can also be administered topically or transdermally.
Pharmaceutical formulations according to the present invention are provided which include any of the compounds described above in combination with a pharmaceutically acceptable carrier.
The compounds described above can also be used to treat cancer.
Further objects, features and advantages of the invention will be apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B respectively show plasma concentration versus time curves for intravenous and intraportal dosing of treprostinil diethanolamine salt in rats as described in Example 1;
FIGS. 2A , 2 B and 2 C respectively show plasma concentration versus time curves for intraduodenal, intracolonic and oral dosing of treprostinil diethanol amine salt in rats as described in Example 1;
FIG. 3 shows on a logarithmic scale the average plasma concentration versus time curves for the routes of administration described in Example 1;
FIG. 4 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following oral administration in rats of treprostinil methyl ester as described in Example 2;
FIG. 5 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following oral administration in rats of treprostinil benzyl ester as described in Example 2;
FIG. 6 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following oral administration in rats of treprostinil diglycine as described in Example 2;
FIG. 7 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following oral administration in rates of treprostinil benzyl ester (0.5 mg/kg) and treprostinil diglycine (0.5 mg/kg) as described in Example 2 compared to treprostinil (1 mg/per kg).
FIG. 8 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following intraduodenal administration of treprostinil monophosphate (ring) as described in Example 3;
FIG. 9 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following intraduodenal administration of treprostinil monovaline (ring) as described in Example 3;
FIG. 10 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following intraduodenal administration of treprostinil monoalanine (ring) as described in Example 3;
FIG. 11 is a graphical representation of the plasma concentration versus time curve for treprostinil in rat following intraduodenal administration of treprostinil monoalanine (chain) as described in Example 3; and
FIG. 12 is a graphical representation of the average plasma concentration versus time curve for each prodrug compared to treprostinil alone from Example 1, as described in Example 3. Treprostinil was dosed at 1 mg/kg whereas the prodrugs were dosed at 0.5 mg/kg.
FIGS. 13A-13D respectively show doses, administered every two hours for four doses, for either 0.05 mg per dose (total=0.2 mg), 0.125 mg per dose (total=0.5 mg), 0.25 mg per dose (total=1.0 mg), or 0.5 mg per dose (total=2.0 mg).
FIG. 14 shows pharmacokinetic profiles of UT-15C sustained release tablets and sustained release capsules, fasted and fed state.
FIG. 15 shows an X ray powder diffraction spectrum of the polymorph Form A.
FIG. 16 shows an IR spectrum of the polymorph Form A.
FIG. 17 shows a Raman spectrum of the polymorph Form A.
FIG. 18 shows thermal data of the polymorph Form A.
FIG. 19 shows moisture sorption data of the polymorph Form A.
FIG. 20 shows an X ray powder diffraction spectrum of the polymorph Form B.
FIG. 21 shows thermal data of the polymorph Form B.
FIG. 22 shows moisture sorption data of the polymorph Form B.
DETAILED DESCRIPTION OF THE INVENTION
Unless otherwise specified, “a” or “an” means “one or more”. The present invention provides compounds and methods for inducing prostacyclin-like effects in a subject or patient. The compounds provided herein can be formulated into pharmaceutical formulations and medicaments that are useful in the methods of the invention. The invention also provides for the use of the compounds in preparing medicaments and pharmaceutical formulations and for use of the compounds in treating biological conditions related to insufficient prostacyclin activity as outlined in the Field of Invention. The present invention also provides compounds and methods for the treatment of cancer and cancer related disorders.
In some embodiments, the present compounds are chemical derivatives of (+)-treprostinil, which has the following structure:
Treprostinil is a chemically stable analog of prostacyclin, and as such is a potent vasodilator and inhibitor of platelet aggregation. The sodium salt of treprostinil, (1R,2R,3aS,9aS)-[[2,3,3a,4,9,9a-Hexahydro-2-hydroxy-1-[(3S)-3-hydroxyoctyl]-1H-benz[f]inden-5-yl]oxy]acetic acid monosodium salt, is sold as a solution for injection as Remodulin® which has been approved by the Food and Drug Administration (FDA) for treatment of pulmonary hypertension. In some embodiments, the present compounds are derivatives of (−)-treprostinil, the enantiomer of (+)-treprostinil. A preferred embodiment of the present invention is the diethanolamine salt of treprostinil. The present invention further includes polymorphs of the above compounds, with two forms, A and B, being described in the examples below. Of the two forms, B is preferred. A particularly preferred embodiment of the present invention is form B of treprostinil diethanolamine.
In some embodiments, the present compounds are generally classified as prodrugs of treprostinil that convert to treprostinil after administration to a patient, such as through ingestion. In some embodiments, the prodrugs have little or no activity themselves and only show activity after being converted to treprostinil. In some embodiments, the present compounds were produced by chemically derivatizing treprostinil to make stable esters, and in some instances, the compounds were derivatized from the hydroxyl groups. Compounds of the present invention can also be provided by modifying the compounds found in U.S. Pat. Nos. 4,306,075 and 5,153,222 in like manner.
In one embodiment, the present invention provides compounds of structure I:
wherein,
R 1 is independently selected from the group consisting of H, substituted and unsubstituted benzyl groups and groups wherein OR 1 are substituted or unsubstituted glycolamide esters;
R 2 and R 3 may be the same or different and are independently selected from the group consisting of H, phosphate and groups wherein OR 2 and OR 3 form esters of amino acids or proteins, with the proviso that all of R 1 , R 2 and R 3 are not H;
enantiomers of the compound; and
pharmaceutically acceptable salts of the compound.
In some embodiments wherein OR 1 are substituted or unsubstituted glycolamide esters, R 1 is —CH 2 CONR 4 R 5 and R 4 and R 5 may be the same or different and are independently selected from the group consisting of H, OH, substituted and unsubstituted alkyl groups, —(CH 2 ) m CH 3 , —CH 2 OH, and —CH 2 (CH 2 ) n OH, with the proviso that m is 0, 1, 2, 3 or 4, and n is 0, 1, 2, 3 or 4.
One skilled in the art will also readily recognize that where members are grouped together in a common manner, such as in a Markush group or the groups described in the R of structures I and II above and below, the present invention encompasses not only the entire group listed as a whole, but each member of the group individually and all possible subgroups of the main group. Accordingly, for all purposes, the present invention encompasses not only the main group, but also the main group absent one or more of the group members. The present invention also envisages the explicit exclusion of one or more of any of the group members in the claimed invention. For example, R 1 can specifically exclude H, substituted and unsubstituted benzyl groups, or groups wherein OR 1 are substituted or unsubstituted glycolamide esters.
In some embodiments, R 1 is a substituted or unsubstituted benzyl groups, such as —CH 2 C 6 H 5 , —CH 2 C 6 H 4 NO 2 , —CH 2 C 6 H 4 OCH 3 , —CH 2 C 6 H 4 Cl, —CH 2 C 6 H 4 (NO 2 ) 2 , or —CH 2 C 6 H 4 F. The benzyl group can be ortho, meta, para, ortho/para substituted and combinations thereof. Suitable substituents on the aromatic ring include halogens (fluorine, chlorine, bromine, iodine), —NO 2 groups, —OR 16 groups wherein R 16 is H or a C 1 -C 4 alkyl group, and combinations thereof.
Alternatively, when R 1 is —CH 2 CONR 4 R 5 then R 4 and R 5 may be the same or different and are independently selected from the group consisting of H, OH, —CH 3 , and —CH 2 CH 2 OH. In these compounds where R 1 is not H, generally one or both of R 2 and R 3 are H.
In some embodiment one or both of R 2 and R 3 are H and R 1 is —CH 2 CONR 4 R 5 , and one or both of R 4 and R 5 are H, —OH, —CH 3 , —CH 2 CH 2 OH.
In compounds where one or both of R 2 and R 3 are not H, R 2 and R 3 can be independently selected from phosphate and groups wherein OR 2 and OR 3 are esters of amino acids, dipeptides, esters of tripeptides and esters of tetrapeptides. In some embodiments, only one of R 2 or R 3 is a phosphate group. In compounds where at least one of R 2 and R 3 is not H, generally R 1 is H. In additional embodiments, one of R 2 and R 3 are H and thus the compound of structure I is derivatized at only one of R 2 and R 3 . In particular compounds, R 2 is H and R 3 is defined as above. In additional embodiments, R 1 and R 3 are H and R 2 is a group wherein OR 2 is an ester of an amino acid or a dipeptide. In further embodiments, R 1 and R 2 are H and R 3 is a group wherein OR 3 is an ester of an amino acid or a dipeptide.
When one or both of the OR 2 and OR 3 groups form esters of amino acids or peptides, i.e., dipeptides, tripeptides or tetrapeptides, these can be depicted generically as —COCHR 6 NR 7 R 8 wherein R 6 is selected from the group consisting of amino acid side chains, R 7 and R 8 may be the same or different and are independently selected from the group consisting of H, and —COCHR 9 NR 10 R 11 . Generally, reference to amino acids or peptides refers to the naturally occurring, or L-isomer, of the amino acids or peptides. However, the present compounds and methods are not limited thereto and D-isomer amino acid residues can take the place of some or all of L-amino acids. In like manner, mixtures of D- and L-isomers can also be used. In the embodiments wherein the amino acid is proline, R 7 together with R 6 forms a pyrrolidine ring structure. R 6 can be any of the naturally occurring amino acid side chains, for example —CH 3 (alanine), —(CH 2 ) 3 NHCNH 2 NH (arginine), —CH 2 CONH 2 (asparagine), —CH 2 COOH (aspartic acid,), —CH 2 SH (cysteine), —(CH 2 ) 2 CONH 2 (glutamine), —(CH 2 ) 2 COOH (glutamic acid), —H (glycine), —CHCH 3 CH 2 CH 3 (isoleucine), —CH 2 CH(CH 3 ) 2 (leucine), —(CH 2 ) 4 NH 2 (lysine), —(CH 2 ) 2 SCH 3 (methionine), —CH2Ph (phenylalanine), —CH 2 OH (serine), —CHOHCH 3 (threonine), —CH(CH 3 ) 2 (valine),
—(CH 2 ) 3 NHCONH 2 (citrulline) or —(CH 2 ) 3 NH 2 (ornithine). Ph designates a phenyl group.
In the above compounds, R 7 and R 8 may be the same or different and are selected from the group consisting of H, and —COCHR 9 NR 10 R 11 , wherein R 9 is a side chain of amino acid, R 10 and R 11 may be the same or different and are selected from the group consisting of H, and —COCHR 12 NR 13 R 14 , wherein R 12 is an amino acid side chain, R 13 and R 14 may be the same or different and are independently selected from the group consisting of H, and —COCHR 15 NH 2 . One skilled in the art will realize that the peptide chains can be extended on the following scheme to the desired length and include the desired amino acid residues.
In the embodiments where either or both of OR 2 and OR 3 groups form an ester of a peptide, such as dipeptide, tripeptide, tetrapeptide, etc. the peptides can be either homopeptides, i.e., repeats of the same amino acid, such as arginyl-arginine, or heteropeptides, i.e., made up of different combinations of amino acids. Examples of heterodipeptides include alanyl-glutamine, glycyl-glutamine, lysyl-arginine, etc.
As will be understood by the skilled artisan when only one R 7 and R 8 includes a peptide bond to further amino acid, such as in the di, tri and tetrapeptides, the resulting peptide chain will be linear. When both R 7 and R 8 include a peptide bond, then the peptide can be branched.
In still other embodiments of the present compounds R 1 is H and one of R 2 or R 3 is a phosphate group or H while the other R 2 or R 3 is a group such the OR 2 or OR 3 is an ester of an amino acid, such as an ester of glycine or alanine.
Pharmaceutically acceptable salts of these compounds as well as pharmaceutical formulation of these compounds are also provided.
Generally, the compounds described herein have enhanced oral bioavailability compared to the oral bioavailability of treprostinil, either in free acid or salt form. The described compounds can have oral bioavailability that is at least 25%, 50% 100%, 200%, 400% or more compared to the oral bioavailability of treprostinil. The absolute oral bioavailability of these compounds can range between 10%, 15%, 20%, 25%, 30% and 40%, 45%, 50%, 55%, 60% or more when administered orally. For comparison, the absolute oral bioavailability of treprostinil is on the order of 10%, although treprostinil sodium has an absolute bioavailability approximating 100% when administered by subcutaneous infusion.
As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein, and in particular the bioavailability ranges described herein also encompass any and all possible subranges and combinations of subranges thereof. As only one example, a range of 20% to 40%, can be broken down into ranges of 20% to 32.5% and 32.5% to 40%, 20% to 27.5% and 27.5% to 40%, etc. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” “more than” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. In the same manner, all ratios disclosed herein also include all subratios falling within the broader ratio.
Administration of these compounds can be by any route by which the compound will be bioavailable in effective amounts including oral and parenteral routes. The compounds can be administered intravenously, topically, subcutaneously, intranasally, rectally, intramuscularly, transdermally or by other parenteral routes. When administered orally, the compounds can be administered in any convenient dosage form including, for example, capsule, tablet, liquid, suspension, and the like.
Testing has shown that that treprostinil can be irritating upon skin contact. In contrast, some of the compounds disclosed herein, generally as prodrugs of treprostinil, are not irritating to the skin. Accordingly, the present compounds are well suited for topical or transdermal administration.
When administered to a subject, the above compounds, and in particular the compounds of structure I, are prostacyclin-mimetic and are useful in treating conditions or disorders where vasodilation and/or inhibition of platelet aggregation or other disorders where prostacyclin has shown benefit, such as in treating pulmonary hypertension. Accordingly, the present invention provides methods for inducing prostacyclin-like effects in a subject comprising administering a pharmaceutically effective amount of one or more of the compounds described herein, such as those of structure I above, preferably orally, to a patient in need of such treatment. As an example, the vasodilating effects of the present compounds can be used to treat pulmonary hypertension, which result from various forms of connective tissue disease, such as lupus, scleroderma or mixed connective tissue disease. These compounds are thus useful for the treatment of pulmonary hypertension.
In another embodiment, the present invention also provides methods of promoting prostacyclin-like effect in a subject by administering a pharmaceutically effective amount of a compound of structure II:
wherein,
R 1 is independently selected from the group consisting of H, substituted and unsubstituted alkyl groups, arylalkyl groups and groups wherein OR 1 form a substituted or unsubstituted glycolamide ester;
R 2 and R 3 may be the same or different and are independently selected from the group consisting of H, phosphate and groups wherein OR 2 and OR 3 form esters of amino acids or proteins, with the proviso that all of R 1 , R 2 and R 3 are not H;
an enantiomer of the compound; and
a pharmaceutically acceptable salt of the compound.
In groups wherein OR 1 form a substituted or unsubstituted glycolamide ester, R 1 can be —CH 2 CONR 4 R 5 , wherein R 4 and R 5 may be the same or different and are independently selected from the group consisting of H, OH, substituted and unsubstituted alkyl groups, —(CH 2 ) m CH 3 , —CH 2 OH, and —CH 2 (CH 2 ) n OH, with the proviso that m is 0, 1, 2, 3 or 4, and n is 0, 1, 2, 3 or 4.
In other methods of inducing vasodilation or treating hypertension, R 1 can be a C 1 -C 4 alkyl group, such as methyl, ethyl, propyl or butyl. In other methods R 1 is a substituted or unsubstituted benzyl groups, such as —CH 2 C 6 H 5 , —CH 2 C 6 H 4 NO 2 , —CH 2 C 6 H 4 OCH 3 , —CH 2 C 6 H 4 Cl, —CH 2 C 6 H 4 (NO 2 ) 2 , or —CH 2 C 6 H 4 F, The benzyl group can be ortho, meta, para, ortho/para substituted and combinations thereof. Suitable substituents on the aromatic ring include halogens (fluorine, chlorine, bromine, iodine), —NO 2 groups, —OR 16 groups wherein R 16 is H or a C 1 -C 4 alkyl group, and combinations thereof.
Alternatively, when R 1 is —CH 2 CONR 4 R 5 then R 4 and R 5 may be the same or different and are independently selected from the group consisting of H, OH, —CH 3 , and —CH 2 CH 2 OH. In these methods, where R 1 is not H, generally one or both of R 2 and R 3 are H.
In some methods, one or both of R 2 and R 3 are H and R 1 is —CH 3 , —CH 2 C 6 H 5 . In other methods where one or both of R 2 and R 3 are H, then R 1 is —CH 2 CONR 4 R 5 , and one or both of R 4 and R 5 are H, —OH, —CH 3 , —CH 2 CH 2 OH.
In methods where one or both of R 2 and R 3 are not H, R 2 and R 3 can be independently selected from phosphate and groups wherein OR 2 and OR 3 are esters of amino acids, dipeptides, esters of tripeptides and esters of tetrapeptides. In some embodiments, only one of R 2 or R 3 is a phosphate group. In methods where at least one of R 2 and R 3 is not H, generally R 1 is H. In other methods, one of R 2 or R 3 is H and the other R 2 or R 3 is as defined elsewhere herein. In some methods, R 2 is H and R 3 is not H. In additional embodiments, R 1 and R 3 are H and R 2 is a group wherein OR 2 is an ester of an amino acid or a dipeptide. In further embodiments, R 1 and R 2 are H and R 3 is a group wherein OR 3 is an ester of an amino acid or a dipeptide.
In the methods, where one or both of the OR 2 and OR 3 groups form esters of amino acids or peptides, i.e., dipeptides, tripeptides or tetrapeptides, these can be depicted generically as —COCHR 6 NR 7 R 8 wherein R 6 is selected from the group consisting of amino acid side chains, R 7 and R 8 may be the same or different and are independently selected from the group consisting of H, and —COCHR 9 NR 10 R 11 . In the embodiments wherein the amino acid is proline, R 7 together with R 6 forms a pyrrolidine ring structure. R 6 can be any of the naturally occurring amino acid side chains, for example —CH 3 (alanine), —(CH 2 ) 3 NHCNH 2 NH (arginine), —CH 2 CONH 2 (asparagine), —CH 2 COOH (aspartic acid,), —CH 2 SH (cysteine), —(CH 2 ) 2 CONH 2 (glutamine), —(CH 2 ) 2 COOH (glutamic acid), —H (glycine), —CHCH 3 CH 2 CH 3 (isoleucine), —CH 2 CH(CH 3 ) 2 (leucine), —(CH 2 ) 4 NH 2 (lysine), —(CH 2 ) 2 SCH 3 (methionine), —CH2Ph (phenylalanine), —CH 2 OH (serine), —CHOHCH 3 (threonine), —CH(CH 3 ) 2 (valine),
—(CH 2 ) 3 NHCONH 2 (citrulline) or —(CH 2 ) 3 NH 2 (ornithine). Ph designates a phenyl group.
In the above methods, R 7 and R 8 may be the same or different and are selected from the group consisting of H, and —COCHR 9 NR 10 R 11 , wherein R 9 is a side chain of amino acid, R 10 and R 11 may be the same or different and are selected from the group consisting of H, and —COCHR 12 NR 13 R 14 , wherein R 12 is an amino acid side chain, R 13 and R 14 may be the same or different and are independently selected from the group consisting of H, and —COCHR 15 NH 2 . One skilled in the art will realize that the peptide chains can be extended on the following scheme to the desired length and include the desired amino acid residues.
In the embodiments where either or both of OR 2 and OR 3 groups form an ester of a peptide, such as dipeptide, tripeptide, tetrapeptide, etc. the peptides can be either homopeptides, i.e., repeats of the same amino residue, or heteropeptides, i.e., made up of different combinations of amino acids.
As will be understood by the skilled artisan when only one of R 7 and R 8 includes a peptide bond to further amino acid, such as in the di, tri and tetrapeptides, the resulting peptide chain will be linear. When both R 7 and R 8 include a peptide bond, then the peptide can be branched.
In still other methods R 1 is H and one of R 2 or R 3 is a phosphate group or H while the other R 2 or R 3 is a group such the OR 2 or OR 3 is an ester of an amino acid, such as an ester of glycine or alanine.
In some methods, the administered compound can have an oral bioavailability that is at least 25%, 50% 100%, 200%, 400% of the oral bioavailability of treprostinil. It is generally preferred to administer compounds that have higher absolute oral bioavailabilities, such as 15%, 20%, 25%, 30% and 40%, 45%, 50%, 55%, 60% or more when administered orally.
Treprostinil has also been discovered to inhibit metastasis of cancer cells as disclosed in U.S. patent application Ser. No. 10/006,197 filed Dec. 10, 2001 and Ser. No. 10/047,802 filed Jan. 16, 2002, both of which are hereby incorporated into this application. Accordingly, the compounds described above, and in particular those of structure I and II, can also be used in the treatment of cancer and cancer related disorders, and as such the present invention provides pharmaceutical compositions and methods for treating cancer. Suitable formulations and methods of using the present compounds can be achieved by substituting the compounds of the present invention, such as those of structure I and II and in particular prodrugs of treprostinil, for the active compounds disclosed in U.S. patent application Ser. Nos. 10/006,197 and 10/047,802 filed Jan. 16, 2002.
Synthesis of the following compounds of structure I and structure II can be achieved as follows:
Synthesis of methyl ester of Treprostinil (2) and biphosphate ester of Treprostinil
Synthesis of methyl ester of Treprostinil (2)
Methyl ester of treprostinil (2) was prepared by treating 1.087 g (2.8 mmoles) of treprostinil (1) with 50 ml of a saturated solution of dry hydrochloric acid in methanol. After 24 hours at room temperature, the methanol was evaporated to dryness and the residue was taken in 200 ml dichloromethane. The dichloromethane solution was washed with a 10% aqueous potassium carbonate solution, and then with water to a neutral pH, it was dried over sodium sulfate, filtered and the solvent was removed in vacuo affording treprostinil methyl ester (2) in 98% yield as a yellow oil. The crude methyl ester was used as such in subsequent reactions.
Synthesis of biphosphate ester of Treprostinil (4)
The procedure was adapted after Steroids, 2(6), 567-603(1963). The methyl ester of treprostinil (2) (60 mg, 0.15 mmoles) was dissolved in 2 ml dry pyridine and a pyridinium solution of the previously prepared pyridinium solution of 2-cyanoethylphosphate 1M (0.3 ml, 0.3 mmoles) (cf. Methods in Enzymology, 1971, 18(c), 54-57) were concentrated to dryness in vacuo at 40° C. Anhydrous pyridine was added and the reaction mixture was again concentrated; the operation was repeated twice in order to remove water completely. Finally the residue was dissolved in 2 ml anhydrous pyridine and 190 mg (0.9 mmoles) dicyclohexylcarbodiimide were added as a solution in 2 ml anhydrous pyridine. The reaction mixture in a closed flask was stirred magnetically for 48 hours at room temperature. 1 ml water was added and after one hour, the mixture was concentrated to a thick paste in vacuo. The reaction mixture was treated overnight at room temperature with 3 ml of a 1/9 water/methanol solution containing 35 mg sodium hydroxide. The white solid (dicyclohexylurea) formed was removed by filtration and it was washed well with water. The aqueous-methanolic solution was concentrated almost to dryness in vacuo, water was added and the solution was extracted with n-butanol (3×2 ml), then with methylene chloride (1×2 ml). The pH of the solution was adjusted to 9.0 by treatment with a sulfonic acid ion exchange resin (H+ cycle-Dowex), treatment with Dowex resin for a longer time (˜12 hours) lead to both the cleavage of the TBDMS group and the recovery of the free carboxyl group. The resin was filtered and the solution was concentrated to dryness affording the corresponding bisphosphate 4 (43 mg, yield 52%).
Synthesis of 3′-monophosphate ester of treprostinil (8) and 2-monophosphate ester of treprostinil (10)
Synthesis of monoprotected TBDMS methyl ester of treprostinil (5 and 6)
The procedure was adapted from Org. Synth., 1998, 75, 139-145. The treprostinil methyl ester (2) (305.8 mg, 0.75 mmoles) was dissolved in 15 ml anhydrous dichloromethane and the solution was cooled on an ice bath to 0° C. Imidazole (102 mg, 1.5 mmoles) and tert-butyldimethyl silyl chloride (226.2 mg, 1.5 mmoles) were added and the mixture was maintained under stirring at 0° C. for 30 minutes, then stirred overnight at room temperature. Water (25 ml) was added and the organic layer was separated. The aqueous layer was then extracted with dichloromethane (3×50 ml). The organic layers were dried over Na 2 SO 4 , the solution was filtered and the solvent was removed in vacuo affording 447 mg crude reaction product. The crude reaction product was separated by column chromatography (silica gel, 35% ethyl acetate/hexanes) affording 140 mg bis-TBDMS protected Treprostinil methyl ester, 160 mg 2-TBDMS protected treprostinil methyl ester (6) and 60 mg 3′-TBDMS protected Treprostinil methyl ester (5).
Synthesis of monophosphate ester of Treprostinil 8/10
The procedure was adapted after Steroids, 1963, 2(6), 567-603 and is the same for (8) and (10) starting from (6) and (5), respectively. The TBDMS protected methyl ester of treprostinil (6) (46 mg, 0.09 mmoles) was dissolved in 2 ml dry pyridine and a pyridinium solution of the previously prepared pyridinium solution of 2-cyanoethyiphosphate 1M (0.2 ml, 0.2 mmoles) (cf. Methods in Enzymology, 1971, 18(c), 54-57) were concentrated to dryness in vacuo at 40° C. Anhydrous pyridine was added and the reaction mixture was again concentrated; the operation was repeated twice in order to remove water completely. Finally the residue was dissolved in 2 ml anhydrous pyridine and 116 mg (0.56 mmoles) dicyclohexylcarbodiimide were added as a solution in 2 ml anhydrous pyridine. The reaction mixture in a closed flask was stirred magnetically for 48 hours at room temperature in the dark. 5 ml water were added and after one hour, the mixture was concentrated to a thick paste in vacuo. The reaction mixture was treated overnight at room temperature with 10 ml of a 1/9 water/methanol solution containing 100 mg sodium hydroxide. The white solid (dicyclohexylurea) formed was removed by filtration and it was washed well with water. The aqueous-methanolic solution was concentrated almost to dryness in vacuo, water was added and the solution was extracted with n-butanol (3×10 ml), then with methylene chloride (1×10 ml). The pH of the solution was adjusted to 9.0 by treatment with a sulfonic acid ion exchange resin (H+ cycle—Dowex); treatment with Dowex resin for a longer time (˜12 hours) lead to both the cleavage of the TBDMS group and the recovery of the free carboxyl group. The resin was filtered and the solution was concentrated to dryness affording the corresponding monophosphate 8 (33 mg, yield 68%).
Synthesis of methyl ester of treprostinil (2)
(2) (1 g; 2.56 mmol) was added to methanol (50 ml) prior saturated with gaseous hydrochloric acid and the mixture swirled to give a clear solution that was left to stand overnight at room temperature. Solvent was removed in vacuo and the residue was neutralized with a 20% potassium carbonate solution and extracted in dichloromethane. The organic layer was washed with water, dried over anhydrous magnesium sulfate and evaporated to yield the crude product (0.96 g). Purification by preparative tic (silica gel plate; eluent: 7:3 (v/v) hexane-ethyl acetate) afforded 2 (0.803; 77.5%), colorless oil.
Synthesis of Tritreprostinil diethanolamine (UT-15C)
Treprostinil acid acid is dissolved in a 1:1 molar ratio mixture of ethanol:water and diethanolamine is added and dissolved. The solution is heated and acetone is added as an antisolvent during cooling.
Synthesis of diglycil ester of treprostinil methyl ester (12)
To a magnetically stirred solution of (2) methyl ester 2 (0.268 g; 0.66 mmol) in dichloromethane (30 ml) N-carbobenzyloxyglycine p-nitrophenyl ester (0.766 g; 2.32 mmol) and 4-(dimethyamino)pyridine (250 mg; 2.05 mmol) were successively added. The resulted yellow solution was stirred at 20° C. for 24 hrs., then treated with 5% sodium hydroxide solution (20 ml) and stirring continued for 15 mm. Dichloromethane (50 ml) was added, layers separated and the organic phase washed with a 5% sodium hydroxide solution (6×20 ml), water (30 ml), 10% hydrochloric acid (2×40 ml), 5% sodium bicarbonate solution (40 ml) and dried over anhydrous sodium sulfate. Removal of the solvent afforded crude (11) (0.61 g), pale-yellow viscous oil. Purification by flash column chromatography on silica gel eluting with gradient 9/1 to 1/2 (v/v) hexane-ethyl ether afforded 0.445 g (85.3%) of 11, white crystals, m.p. 70-72° C. ‘Fl-NMR [CDCl 3 ; δ(ppm)]: 3.786 (s)(3H, COOC H 3 ), 3.875 (d)(2H) and 3.940 (d)(2H)(NH—C H 2 —COO), 4.631 (s) (2H, OC H 2 COOCH3), 4.789 (m)(1H, adjacent to OOC—CH 2 NHcbz) and 4.903 (m) (1H, adjacent to OOCCH 2 NHcbz), 5.09 (s)(4H, C 6 H 5 CH 2 O), 5.378 (m)(1H) and 5.392 (m)(1H)(NH), 7.295-7.329 (m)(10H, C 6 H 5 ). LR ESI-MS (m/z): 787.1 [M+H] + , 804.1 [M+NH4] + , 809.3 [M+Na] + , 825.2 [M+K] + , 1590.5 [2M+NH 4 ] + , 1595.6 [2M+Na]+.
Methyl ester, diglycyl ester (12)
A solution of ester (11) (0.4 g; 0.51 mmol) in methanol (30 ml) was introduced in the pressure bottle of a Parr hydrogenation apparatus, 10% palladium on charcoal (0.2 g; 0.197 mmol Pd) was added, apparatus closed, purged thrice with hydrogen and loaded with hydrogen at 50 p.s.i. Stirring was started and hydrogenation carried out for 5 hrs. at room temperature. Hydrogen has removed from the installation by vacuum suction and replaced with argon. The catalyst was filtered off through celite deposited on a fit and the filtrate concentrated in vacuo to give 0.240 g (91%) of 4, white solid m.p. 98-100° C.
Synthesis of benzyl ester of treprostinil (13)
To a stirred solution of (2) (2 g; 5.12 mmol) in anhydrous tetrahydrofuran (20 ml) benzyl bromide (0.95 ml; 7.98 mmol) and freshly distilled triethylamine (1.6 ml; 11.48 mmol) were consecutively added at room temperature and the obtained solution was refluxed with stirring for 12 hrs. A white precipitate was gradually formed. Solvent was distilled off in vacuo and the residue treated with water (30 ml). Upon extraction with methylene chloride emulsion formation occurs. The organic and aqueous layers could be separated only after treatment with 5% hydrochloric acid solution (20 ml). The organic layer was washed with water, dried on anhydrous sodium sulfate, and evaporated, the residue was further dried under reduced pressure over phosphorus pentoxide to give a yellow viscous oil (2.32 g) that was purified by preparative thin layer chromatography (silica gel plate; eluent: 1:2, v/v, hexane/ethyl ether). Yield: 81.2%.
Synthesis of bis-glycyl ester of treprostinil (15)
Benzy ester, di-cbzGly ester (14)
To a magnetically stirred solution of benzyl ester 13 (1 g; 2.08 mmol) in dichloromethane (50 ml) N-carbobenzyloxyglycine p-nitrophenyl ester (2.41 g; 7.28 mmol) and 4-(dimethyamino) pyridine (788 mg; 6.45 mmol) were added. The resulted yellow solution was stirred at 20° C. for 21 hrs., then successively washed with a 5% sodium hydroxide solution (6×45 ml), 10% hydrochloric acid (2×40 ml), 5% sodium bicarbonate solution (40 ml) and dried over anhydrous sodium sulfate. Removal of the solvent, followed by drying over phosphorus pentoxide under reduced pressure, afforded crude 14 (2.61 g), pale-yellow oil. Purification by flash column chromatography on silica gel eluting with gradient 9:1 to 1:2 (v/v) hexane-ethyl ether gave (14_(1.51 g; 84.1%) as a colorless, very viscous oil.
Diglycyl ester (15)
A solution of ester (14) (0.4 g; 0.46 mmol) in methanol (30 ml) was hydrogenated over 10% Pd/C as described for ester (12). Work-up and drying over phosphorus pentoxide in vacuo yielded 0.170 g (72.7%) of ester 15, white solid m.p. 155-158° C.
Synthesis of 3′-glycyl ester of treprostinil 19
Benzyl ester, t-butyldimethysilyl monoester (16)
A solution of tert-butyldimethylsilyl chloride (0.45 g; 2.98 mmol) in dichloromethane (8 ml) was added dropwise over 10 min., at room temperature, into a stirred solution of benzyl ester 13 (0.83 g; 1.73 mmol) and imidazole (0.33 g; 4.85 mmol) in dichloromethane (20 ml). Stirring was continued overnight then water (20 ml) was added, the mixture stirred for one hour, layers separated, organic layer dried over anhydrous sodium sulfate and concentrated in vacuo to give a slightly yellow oil (1.15 g). The crude product is a mixture of the mono-TBDMS (16) and di-TBDMS esters ( 1 H-NMR). Column chromatography on silica gel, eluting with a 9:1 (v/v) hexane-ethyl acetate mixture, readily afforded the di-ester (0.618 g) in a first fraction, and ester 16 (0.353 g; yield relative to 13: 34.4%) in subsequent fractions. Analytical tlc on silica gel of the ester 16 showed only one spot (eluent: 3:2 (v/v) hexane-ethyl ether). Consequently, under the above reaction conditions, the other possible isomer (mono-TBDMS ester at the side-chain hydroxyl) was not observed.
Another experiment in which the molar ratio tert-butyldimethylsilyl chloride: ester 13 was lowered to 1.49 (followed by flash column chromatography of the product on silica gel, eluting with gradient 9.5/0.5 to 3/1 (v/v) hexane-ethyl ether) lead to a decreased content (36.5%, as pure isolated material) of the undesired di-OTBDMS by-product. The mono-OTBDMS ester fractions (45.1%; isolated material) consisted of ester 16 (98%) and its side-chain isomer (2%) that could be distinctly separated; the latter was evidenced (tlc, NMR) only in the last of the monoester fractions.
Benzyl ester, cbz-glycyl monoester (18)
To a magnetically stirred solution of ester 16 (0.340 g; 0.57 mmol) in dichloromethane (15 ml) N-carbobenzyloxyglycine p-nitrophenyl ester (0.445 g; 1.35 mmol) and 4-(dimethyamino) pyridine (150 mg; 1.23 mmol) were successively added. The solution was stirred at 20° C. for 40 hrs. Work-up as described for esters 11 and 14 yielded a crude product (0.63 g) containing 90% 17 and 10% 18 ( 1 H-NMR). To completely remove the protective TBDMS group, this mixture was dissolved in ethanol (30 ml) and subjected to acid hydrolysis (5% HCl, 7 ml) by stirring overnight at room temperature. Solvent was then removed under reduced pressure and the residue extracted in dichloromethane (3×50 ml); the organic layer was separated, washed once with water (50 ml), dried over sodium sulfate and concentrated in vacuo to give crude ester 18 (0.51 g). Purification by flash column chromatography as for esters 11 and 14 afforded ester 18 (0.150 g; overall yield: 39.1%) as a colorless, viscous oil.
Glycyl monoester (19)
A solution of ester 18 (0.15 g; 0.22 mmol) in methanol (30 ml) was hydrogenated over 10% Pd/C as described for ester 12 and 15. Work-up and drying over phosphorus pentoxide in vacuo yielded ester 10 (0.98 g; 98.0%), white, shiny crystals m.p. 74-76° C. LR ESI-MS (m/z): 448.2 [M+H] + , 446.4 [M−H] − .
Synthesis of 3′-L-leucyl ester of treprostinil 22
Benzyl ester, t-butyldimethysilyl monoester, cbz-L-leucyl monoester (20)
To a stirred solution of ester 16 (0.38 g: 0.64 mmol) and N-carbobenzyloxy-L-leucine N-hydroxysuccinimide ester (0.37 g; 1.02 mmol) in 10 ml dichloromethane 4-(dimethyamino)pyridine (0.17 g; 1.39 mmol) was added, then stirring continued at room temperature for 2 days. The solvent was removed in vacuo and the crude product (0.9 g) subjected to flash column chromatography on silica gel eluting with 9:1 hexane-ethyl acetate; the firstly collected fraction yielded an oil (0.51 g) which, based on the its NMR spectrum and tlc, was proved to be a 2:1 mixture of ester 20 and the starting ester 16. Preparative tic on silica gel (eluent: ethyl acetate-hexane 1:4) gave pure 20, colorless oil (overall yield based on 7: 62.6%).
Benzyl ester, cbz-L-leucyl monoester (21)
De-protection of the cyclopentenyl hydroxyl in the t-butyldimethysilyl monoester 20 succeeded by treatment with diluted hydrochloric acid solution as described for 18, with the exception that a 1:5 (v/v) chloroform-ethanol mixture, instead of ethanol alone, was used to ensure homogeneity. Work-up afforded 20, colorless oil, in 87.6% yield.
L-leucyl monoesler (22)
Hydrogenolysis of the benzyl and N-carbobenzyloxy groups in 21 was carried out as for 18. Work-up afforded 22 (95.3%), white solid, m.p. 118-120° C.
Synthesis of 2-L-leucyl ester of treprostinil 25
Benzyl ester, cbz-L-Ieucyl monoesters (21, 23) and -diester (24)
To a stirred solution of ester 13 (0.53 g: 1.10 mmol) and N-carbobenzyloxy-L-leucine N-hydroxysuccinimide ester (0.76 g; 2.05 mmol) in dichloromethane (30 ml) 4-(dimethyamino) pyridine (0.29 g; 2.37 mmol) was added, then stirring continued at room temperature for 1 day. The solution was diluted with dichioromethane (40 mnl), successively washed with a 5% sodium hydroxide solution (4×25 ml), 10% hydrochloric acid (2×30 ml), 5% sodium bicarbonate solution (50 ml), dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product (0.85 g), as a viscous, yellow oil. Thin layer chromatography revealed a complex mixture in which esters 13 and 21 as well as cbz-L-leucine could be identified through the corresponding r F values, only as minor products. The crude product was flash-chromatographed through a silica gel column eluting with gradient hexane-ethyl ether. At 7:3 (v/v) hexane-ethyl ether, the first fraction gave the cbz-L-leucyl diester 24 (6% of the product subjected to chromatography) while the two subsequent fractions afforded the cbz-L-leucyl monoester 23 (54% of the crude product, as pure isolated 23; 57.6% yield, relative to 2). Purity of both compounds was verified by analytical tlc and NMR. The other isomer, cbz-L-leucyl monoester 21 constituted only about 5% of the crude product and was isolated by preparative tlc of the latter only a 3:1 23/21 mixture.
L-leucyl monoester (25)
Hydrogenolysis of 23 to the ester 25 was performed as described for compound 12 but reaction was carried out at 35 p.s.i., overnight. Work-up and drying over phosphorus pentoxide in vacuo afforded 25, white solid m. p. 153-155° C., in quantitative yield.
Synthesis of 3′-L-alanyl ester of treprostinil 30
N-Cbz-L-alanyl p-nitro phenyl ester (27)
To a stirred solution containing N-carbobenzyloxy-L-alanine (1 g; 4.48 mmol) and p-nitrophenol (1 g; 7.19 mmol) in anhydrous tetrahydrofuran (7 ml) a fine suspension of 1,3-dicyclohexylcarbodiimide (1.11 g; 5.38 mmol) in tetrahydrofuran (5 ml) was added over 30 min. Stirring was continued at room temperature for 18 hrs., glacial acetic acid (0.3 ml) added, 1,3-dicyclohexylurea filtered off and solvent removed in vacuo, at 40° C., to give a viscous, yellow-reddish oil (2.5 g). The 1 H-NMR spectrum showed a mixture consisting of N-carbobenzyloxy-Lalanine p-nitrophenyl ester (27), unreacted p-nitrophenol and a small amount of DCU, which was used as such in the next reaction step.
Benzyl ester, cbz-L-alanyl monoester (29)
A solution of 4-(dimethylamino)pyridine (0.30 g; 2.49 mmol) in dichloromethane (3 ml) was quickly dropped (over 5 min.) into a magnetically stirred solution of ester 16 (0.37 g; 0.62 mmol) and crude N-carbobenzyloxy-L-alanine p-nitrophenyl ester (0.98 g) in dichloromethane (12 ml). The mixture was stirred overnight at room temperature, then diluted with dichloromethane (50 ml), and thoroughly washed with a 5% sodium hydroxide solution (7×35 ml), 10% hydrochloric acid (3×35 ml), 5°/a sodium bicarbonate solution (50 ml), dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude ester 28 (1.1 g). The latter was dissolved in ethanol (30 ml), 5% hydrochloric acid (8 ml) and chloroform (5 ml) were added and the solution stirred overnight. Solvents were removed in vacuo, the residue taken-up in dichloromethane, washed to pH 7 with a 5% sodium hydrogencarbonate solution, dried over anhydrous sodium sulfate and the solvent evaporated affording crude 29 (1.04 g). Purification by column chromatography on silica gel, eluting with gradient hexane-ethyl ether, enabled separation of a fraction (at hexane: ethyl ether=1:1 v/v) of pure 29 as a colorless very viscous oil (0.11 g; 25.8% overall yield, based on 16).
L-alanyl monoester (30)
Removal of the benzyl and N-carbobenzyloxy groups in 29 was achieved through catalytic hydrogenation as described for 12. Ester 30 was obtained (yield: 97.2%) as a pale-yellow, partially crystallized, oil.
Synthesis of the 3′-L-valine ester of Treprostinil benzyl ester 33
Synthesis of the benzyl ester of Treprostinil 13
The benzyl ester 11 was synthesized by adapting the method described by J. C. Lee et al. in Organic Prep. and Proc. Intl., 1996, 28(4), 480-483. To a solution of 1 (620 mg, 1.6 mmoles) and cesium carbonate (782.4 mg, 2.4 mmoles) in acetonitrile (30 ml) was added benzyl bromide (0.48 ml, 4 mmoles) and the mixture was stirred at reflux for 1 hour. After cooling at room temperature, the precipitate was filtered off and the filtrate was concentrated in vacuo. The residue was dissolved in chloroform (150 ml) and washed with a 2% aqueous solution of NaHCO 3 (3×30 ml). The organic layer was washed with brine, dried on Na 2 SO 4 , filtered and the solvent was removed in vacuo to afford 750 mg of the crude benzyl ester 13 (yield 98%) as a yellow viscous oil. The crude benzyl ester 13 can be purified by column chromatography (100-0% dichioromethane(methanol) but it can also be used crude in subsequent reactions.
Synthesis of the TBDMS protected Treprostinil benzyl ester 16
The procedure for the synthesis of the TBDMS protected benzyl ester was adapted from Organic Synth., 1998, 75, 139-145. The benzyl ester 13 (679 mg, 1.4 mmoles) was dissolved in anhydrous dichloromethane (20 ml) and the solution was cooled to 0° C. on an ice bath. Imidazole (192 mg, 2.8 mmoles) and t-butyl-dimethylsilyl chloride (TBDMSC1) (420 mg, 2.8 mmoles) were added and the mixture was maintained under stirring for another half hour on the ice bath and then it was left overnight at room temperature. 40 ml water was added to the reaction mixture and the organic layer was separated. The aqueous layer was extracted with 3×50 ml dichloromethane. The combined organic layers were dried over Na 2 SO 4 , filtered and the solvent was removed in vacuo. This afforded 795 mg of material which proved to be a mixture of the desired mono TBDMS protected 5 benzyl ester with the bis-TBDMS protected benzyl ester. Pure 16 (249 mg) was obtained by column chromatography on silica gel (eluent 35% ethyl acetate/hexane).
Synthesis of N-Cbz-L-valine ester of the TBDMS protected Treprostinil benzyl ester 31
The procedure used was adapted from Tetrahedron Lett., 1978, 46, 4475-4478. A solution of NCbz-L-valine (127 mg, 0.5 mmoles), N,N-dicyclohexylcarbodiimide (DCC) (111 mg, 0.5 mmoles), compound 16 (249 mg, 0.4 mmoles) and 4-(dimethylamino)pyridine (DMAP) (6 mg, 0.05 mmoles) in anhydrous dichloromethane (15 ml) was stirred at room temperature until esterification was complete. The solution was filtered and the formed N,N-dicyclohexylurea was filtered. The filtrate was diluted with dichloromethane (80 ml) and washed with water (3×30 ml), a 5% aqueous acetic acid solution (2×30 ml) and then again with water (3×30 ml). The organic layer was dried over Na 2 SO 4 and the solvent was evaporated in vacuo affording 369 mg crude 31. Pure 31 was obtained by chromatography (silica gel, 35% ethyl acetate/hexane).
Synthesis of the 3′-N-Cbz-L-valine ester of Treprostinil benzyl ester 32
Cleavage of the TBDMS group in compound 31 was achieved using an adaptation of the procedure described in Org. Letters, 2000, 2(26), 4177-4180. The N-Cbz-L-valine ester of the TBDMS protected benzyl ester 31 (33 mg, 0.04 mmoles) was dissolved in methanol (5 ml) and tetrabutylammonium tribromide (TBATB) (2 mg, 0.004 mmoles) was added. The reaction mixture was stirred at room temperature for 24 hrs until the TBDMS deprotection was complete. The methanol was evaporated and the residue was taken in dichloromethane. The dichloromethane solution was washed with brine and then dried over Na 2 SO 4 . After filtering the drying agent the solvent was evaporated to dryness affording 30.2 mg of crude compound 32.
Synthesis of the 3′-L-valine ester of Treprostinil 33
The benzyl and benzyl carboxy groups were removed by catalytic hydrogenation at atmospheric pressure in the presence of palladium 10% wt on activated carbon. The 3′-N-Cbz-L-valine ester of benzyl ester 32 (30.2 mg, 0.04 mmoles) was dissolved in methanol (10 ml) and a catalytic amount of Pd/C was added. Under magnetic stirring the air was removed from the flask and then hydrogen was admitted. The reaction mixture was maintained under hydrogen and stirring at room temperature for 24 hrs, then the hydrogen was removed with vacuum. The reaction mixture was then filtered through a layer of celite and the solvent was removed in vacuo to afford the pure 3′-L-valine ester of Treprostinil 33 (15 mg, 0.03 mmoles).
Synthesis of 2-L-valine ester of Treprostinil 36/bis-L-valine ester of Trenrostinil 37
Synthesis of 2-L-alanine ester of Treprostinil 36′/bis-L-alanine ester of Treprostinil 37′
Synthesis of 2-N-Cbz-L-valine ester of Treprostinil benzyl ester 34 and bis-N-Cbz-L-valine ester of Treprostinil benzyl ester 35
The procedure used was adapted from Tetrahedron Lett., 1978, 46, 4475-4478. A solution of NCbz-L-valine (186 mg, 0.7 mmoles), N,N-dicyclohexylcarbodiimide (DCC) (167 mg, 0.8 mmoles), compound 13 (367 mg, 0.8 mmoles) and 4-(dimethylamino)pyridine (DMAP) (12 mg, 0.09 mmoles) in anhydrous dichloromethane (15 ml) was stirred at room temperature until esterification was complete. The solution was filtered and the formed N,N-dicyclohexylurea was filtered. The filtrate was diluted with dichloromethane (100 ml) and washed with water (3×50 ml), a 5% aqueous acetic acid solution (2×50 ml) and then again with water (3×50 ml). The organic layer was dried over Na 2 SO 4 and the solvent was evaporated in vacuo affording 556 mg crude product. The product was separated by chromatography (silica gel, 35% ethyl acetate/hexane) yielding 369.4 mg 2-valine ester 34 and 98 mg bis-valine ester 35.
Synthesis of 2 N-Cbz-L-alanine ester of Treprostinil benzyl ester 34′ and bis-N-Cbz-L-alanine ester of Treprostinil benzyl ester 35′
The procedure used was adapted from Tetrahedron Lett., 1978, 46, 4475-4478. A solution of NCbz-L-alanine (187 mg, 0.84 mmoles), N,N-dicyclohexylcarbodiimide (DCC) (175 mg, 0.85 mmoles), compound 13 (401 mg, 0.84 mmoles) and 4-(dimethylamino)pyridine (UMAP) (11.8 mg, 0.1 mmoles) in anhydrous dichloromethane (15 ml) was stirred at room temperature until esterification was complete. The solution was filtered and the formed N,N-dicyclohexylurea was filtered. The filtrate was diluted with dichloromethane (100 ml) and washed with water (3×50 ml), a 5% aqueous acetic acid solution (2×50 ml) and then again with water (3×50 ml). The organic layer was dried over Na 2 SO 4 and the solvent was evaporated in vacuo affording 516 mg crude product. The product was separated by chromatography (silica gel, 35% ethyl acetate/hexane) yielding 93.4 mg 2-alanine ester 34′ and 227 mg bis-alanine ester 35′.
Synthesis of 2-L-valine ester of Treprostinil 36/bis-L-valine ester of Treprostinil 37
The benzyl and benzyl carboxy groups were removed by catalytic hydrogenation at atmospheric pressure in the presence of palladium 10% wt on activated carbon. The 2-N-Cbz-L-valine ester of Treprostinil benzyl ester 34 (58.2 mg, 0.08 mmoles)/bis-N-Cbz-L-valine ester of Treprostinil benzyl ester 35 (55.1 mg, 0.06 mmoles) was dissolved in methanol (10 ml) and a catalytic amount of Pd/C was added. Under magnetic stirring the air was removed from the flask and hydrogen was admitted. The reaction mixture was maintained under hydrogen and stirring at room temperature for 20 hrs, then hydrogen was removed with vacuum. The reaction mixture was then filtered through a layer of celite and the solvent was removed in vacuo to afford the pure 2-L-valine ester of Treprostinil 36 (40 mg, 0.078 mmoles)/bis-L-valine ester of Treprostinil 37 (23 mg, 0.04 mmoles).
Synthesis of 2-L-alanine ester of Treprostinil 36′/bis-L-alanine ester of Treprostinil 37′
The benzyl and benzyl carboxy groups were removed by catalytic hydrogenation at atmospheric pressure in the presence of palladium 10% wt on activated carbon. The 2-N-Cbz-L-alanine ester of Treprostinil benzyl ester 34′ (87.4 mg, 0.13 mmoles)/bis-N-Cbz-L-alanine ester of Treprostinil benzyl ester 35′ (135 mg, 0.15 mmoles) was dissolved in methanol (15 ml) and a catalytic amount of Pd/C was added. Under magnetic stirring the air was removed from the flask and hydrogen was admitted. The reaction mixture was maintained under hydrogen and stirring at room temperature for 20 hrs, then hydrogen was removed with vacuum. The reaction mixture was then filtered through a layer of celite and the solvent was removed in vacuo to afford the pure 2-L-valine ester of Treprostinil 36′ (57 mg, 0.12 mmoles)/bis-L-alanine ester of Treprostinil 37′ (82 mg, 0.15 mmoles).
Synthesis of benzyl esters of treprostinil 38 a-e
a 4-NO 2 C 6 H 4 CH 2 ; b 4-(CH 3 O)C 6 H 4 CH 2 ; c 2-ClC 6 H 4 CH 2 ; d 2,4-(NO 2 ) 2 C 6 H 3 CH 2 ; e 4-FC 6 H 4 CH 2 Synthesis of the benzyl esters of treprostinil 38 a-e was performed using the procedure for the benzyl ester 13.
Enantiomers of these compounds, shown below, can be synthesized using reagents and synthons of enantiomeric chirality of the above reagents.
(−)-treprostinil can be synthesized as follows:
(a) (S)-2-methyl-CBS-oxazaborolidine, BH 3 .SMe 2 , THF, −30° C., 85%. (b) TBDMSCl, imidazole, CH 2 Cl 2 , 95%. (c) Co 2 (CO) 8 , CH 2 Cl 2 , 2 hr. r.t., then CH 3 CN, 2 hr. reflux. 98%. (d) K 2 CO 3 , Pd/C (10%), EtOH, 50 psi/24 hr. 78% (e) NaOH, EtOH, NaBH 4 . 95%. (f) BnBr, NaH, THF, 98%. (g).CH 3 OH, TsOH. 96%. (h) i. p-nitrobenzoic acid, DEAD, TPP, benzene. (i) CH 3 OH, KOH. 94%. (j) Pd/C (10%), EtOH, 50 psi/2 hr. quant. (k). Ph 2 PLi, THF. (1) i. ClCH 2 CN, K 2 CO 3 . ii, KOH, CH 3 OH, reflux. 83% (2 steps).
Briefly, the enantiomer of the commercial drug (+)-Treprostinil was synthesized using the stereoselective intramolecular Pauson Khand reaction as a key step and Mitsunobu inversion of the side-chain hydroxyl group. The absolute configuration of (−)-Treprostinil was confirmed by an X-ray structure of the L-valine amide derivative.
The following procedure was used to make (−)-treprostinil-methyl-L-valine amide: To a stirred solution of (−)-Treprostinil (391 mg, 1 mmol) and L-valine methyl ester hydrochloride (184 mg, 1.1 mmol) in DMF (10 ml) under Ar was sequentially added pyBOP reagent (1.04 g, 2 mmol), diisopropylethyl amine (0.52 ml, 3 mmol). The reaction mixture was stirred at room temperature overnight (15 hrs). Removal of the solvent in vacuo and purification by chromatography yielded white solid 12 (481 mg, 86%), which was recrystallized (10% ethyl acetate in hexane) to give suitable crystals for X-ray.
Various modifications of these synthetic schemes capable of producing additional compounds discussed herein will be readily apparent to one skilled in the art.
There are two major barriers to deliver treprostinil in the circulatory system. One of these barriers is that treprostinil undergoes a large first pass effect. Upon first circulating through the liver, about 60% of treprostinil plasma levels are metabolized, which leaves only about 40% of the absorbed dose. Also, a major barrier to oral delivery for treprostinil is that the compound is susceptible to an efflux mechanism in the gastrointestinal tract. The permeability of treprostinil has been measured across Caco-2 cell monolayers. The apical to basal transport rate was measured to be 1.39×10 6 cm/sec, which is indicative of a highly permeable compound. However, the basal to apical transport rate was 12.3×10 6 cm/sec, which suggests that treprostinil is efficiently effluxed from the serosal to lumenal side of the epithelial cell. These data suggest that treprostinil is susceptible to p-glycoprotein, a membrane bound multidrug transporter. It is believed that the p-glycoprotein efflux pump prevents certain pharmaceutical compounds from traversing the mucosal cells of the small intestine and, therefore, from being absorbed into systemic circulation.
Accordingly, the present invention provides pharmaceutical compositions comprising treprostinil, the compound of structure I or the compound of structure II, or their pharmaceutically acceptable salts and combinations thereof in combination with one or more inhibitors of p-glycoprotein. A number of known non-cytotoxic pharmacological agents have been shown to inhibit p-glycoprotein are disclosed in U.S. Pat. Nos. 6,451,815, 6,469,022, and 6,171,786.
P-glycoprotein inhibitors include water soluble forms of vitamin E, polyethylene glycol, poloxamers including Pluronic F-68, polyethylene oxide, polyoxyethylene castor oil derivatives including Cremophor EL and Cremophor RH 40, Chrysin, (+)-Taxifolin, Naringenin, Diosmin, Quercetin, cyclosporin A (also known as cyclosporine), verapamil, tamoxifen, quinidine, phenothiazines, and 9,10-dihydro-5-methoxy-9-oxo-N-[4-[2-(1,2,3,4-tetrahydro-6,7,-dimethoxy-2-isoquinolinyl)ethyl]phenyl]-4-acridinecarboxamide or a salt thereof.
Polyethylene glycols (PEGs) are liquid and solid polymers of the general formula H(OCH 2 CH 2 ) n OH, where n is greater than or equal to 4, having various average molecular weights ranging from about 200 to about 20,000. PEGs are also known as alpha-hydro-omega-hydroxypoly-(oxy-1,2-ethanediyl)polyethylene glycols. For example, PEG 200 is a polyethylene glycol wherein the average value of n is 4 and the average molecular weight is from about 190 to about 210. PEG 400 is a polyethylene glycol wherein the average value of n is between 8.2 and 9.1 and the average molecular weight is from about 380 to about 420. Likewise, PEG 600, PEG 1500 and PEG 4000 have average values of n of 12.5-13.9, 29-36 and 68-84, respectively, and average molecular weights of 570-630, 1300-1600 and 3000-3700, respectively, and PEG 1000, PEG 6000 and PEG 8000 have average molecular weights of 950-1050, 5400-6600, and 7000-9000, respectively. Polyethylene glycols of varying average molecular weight of from 200 to 20000 are well known and appreciated in the art of pharmaceutical science and are readily available.
The preferred polyethylene glycols for use in the instant invention are polyethylene glycols having an average molecular weight of from about 200 to about 20,000. The more preferred polyethylene glycols have an average molecular weight of from about 200 to about 8000. More specifically, the more preferred polyethylene glycols for use in the present invention are PEG 200, PEG 400, PEG 600, PEG 1000, PEG 1450, PEG 1500, PEG 4000, PEG 4600, and PEG 8000. The most preferred polyethylene glycols for use in the instant invention is PEG 400, PEG 1000, PEG 1450, PEG 4600 and PEG 8000.
Polysorbate 80 is an oleate ester of sorbitol and its anhydrides copolymerized with approximately 20 moles of ethylene oxide for each mole of sorbitol and sorbitol anhydrides. Polysorbate 80 is made up of sorbitan mono-9-octadecanoate poly(oxy-1,2-ethandiyl) derivatives. Polysorbate 80, also known as Tween 80, is well known and appreciated in the pharmaceutical arts and is readily available.
Water-soluble vitamin E, also known as d-alpha-tocopheryl polyethylene glycol 1000 succinate [TPGS], is a water-soluble derivative of natural-source vitamin E. TPGS may be prepared by the esterification of the acid group of crystalline d-alpha-tocopheryl acid succinate by polyethylene glycol 1000. This product is well known and appreciated in the pharmaceutical arts and is readily available. For example, a water-soluble vitamin E product is available commercially from Eastman Corporation as Vitamin E TPGS.
Naringenin is the bioflavonoid compound 2,3-dihydro-5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one and is also known as 4′,5,7-trihydroxyflavanone. Naringenin is the aglucon of naringen which is a natural product found in the fruit and rind of grapefruit. Naringenin is readily available to the public from commercial sources.
Quercetin is the bioflavonoid compound 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one and is also known as 3,3′,4′,5,7-pentahydroxyflavone. Quercetin is the aglucon of quercitrin, of rutin and of other glycosides. Quercetin is readily available to the public from commercial sources.
Diosmin is the naturally occurring flavonic glycoside compound 7-[[6-O-6-deoxy-alpha-L-mannopyranosyl)-beta-D-glucopyranosyl]oxy]-5-hydroxy-2-(3-hydroxy-4-methoxyphenyl)-4H-1-benzopyran-4-one. Diosmin can be isolated from various plant sources including citrus fruits. Diosmin is readily available to the public from commercial sources.
Chrysin is the naturally occurring compound 5,7-dihydroxy-2-phenyl-4H-1-benzopyran-4-one which can be isolated from various plant sources. Chrysin is readily available to the public from commercial sources.
Poloxamers are alpha-hydro-omega-hydroxypoly(oxyethylene)poly(oxypropylene)poly(oxyethylene) block copolymers. Poloxamers are a series of closely related block copolymers of ethylene oxide and propylene oxide conforming to the general formula HO(C 2 H 4 O) a (C 3 H 6 O) b (C 2 H 4 O) a H. For example, poloxamer 124 is a liquid with “a” being 12, “b” being 20, and having an average molecular weight of from about 2090 to about 2360; poloxamer 188 is a solid with “a” being 80, “b” being 27, and having an average molecular weight of from about 7680 to about 9510; poloxamer 237 is a solid with “a” being 64, “b” being 37, and having an average molecular weight of from about 6840 to about 8830; poloxamer 338 is a solid with “a” being 141, “b” being 44, and having an average molecular weight of from about 12700 to about 17400; and poloxamer 407 is a solid with “a” being 101, “b” being 56, and having an average molecular weight of from about 9840 to about 14600. Poloxamers are well known and appreciated in the pharmaceutical arts and are readily available commercially. For example, Pluronic F-68 is a commercially available poloxamer from BASF Corp. The preferred poloxamers for use in the present invention are those such as poloxamer 188, Pluronic F-68, and the like.
Polyoxyethylene castor oil derivatives are a series of materials obtained by reacting varying amounts of ethylene oxide with either castor oil or hydrogenated castor oil. These polyoxyethylene castor oil derivatives are well known and appreciated in the pharmaceutical arts and several different types of material are commercially available, including the Cremophors available from BASF Corporation. Polyoxyethylene castor oil derivatives are complex mixtures of various hydrophobic and hydrophilic components. For example, in polyoxyl 35 castor oil (also known as Cremophor EL), the hydrophobic constituents comprise about 83% of the total mixture, the main component being glycerol polyethylene glycol ricinoleate. Other hydrophobic constituents include fatty acid esters of polyethylene glycol along with some unchanged castor oil. The hydrophilic part of polyoxyl 35 castor oil (17%) consists of polyethylene glycols and glyceryl ethoxylates.
In polyoxyl 40 hydrogenated castor oil (Cremophor RH 40) approximately 75% of the components of the mixture are hydrophobic. These comprise mainly fatty acid esters of glycerol polyethylene glycol and fatty acid esters of polyethylene glycol. The hydrophilic portion consists of polyethylene glycols and glycerol ethoxylates. The preferred polyoxyethylene castor oil derivatives for use in the present invention are polyoxyl 35 castor oil, such as Cremophor EL, and polyoxyl 40 hydrogenated castor oil, such as Cremophor RH 40. Cremophor EL and Cremophor RH 40 are commercially available from BASF Corporation.
Polyethylene oxide is a nonionic homopolymer of ethylene oxide conforming to the general formula (OCH 2 CH 2 ) n in which n represents the average number of oxyethylene groups. Polyethylene oxides are available in various grades which are well known and appreciated by those in the pharmaceutical arts and several different types of material are commercially available. The preferred grade of polyethylene oxide is NF and the like which are commercially available.
(+)-Taxifolin is (2R-trans)-2-(3,4-dihydroxyphenyl)-2,3-dihydro-3,5,7-trihydroxy-4H-1-benzo pyran-4-one. Other common names for (+)-taxifolin are (+)-dihydroquercetin; 3,3′,4′,5,7-pentahydroxy-flavanone; diquertin; taxifoliol; and distylin. (+)-Taxifolin is well know and appreciated in the art of pharmaceutical arts and is readily available commercially.
The preferred p-glycoprotein inhibitor for use in the present invention are water soluble vitamin E, such as vitamin E TPGS, and the polyethylene glycols. Of the polyethylene glycols, the most preferred p-glycoprotein inhibitors are PEG 400, PEG 1000, PEG 1450, PEG 4600 and PEG 8000.
Administration of a p-glycoprotein inhibitor may be by any route by which the p-glycoprotein inhibitor will be bioavailable in effective amounts including oral and parenteral routes. Although oral administration is preferred, the p-glycoprotein inhibitors may also be administered intravenously, topically, subcutaneously, intranasally, rectally, intramuscularly, or by other parenteral routes. When administered orally, the p-glycoprotein inhibitor may be administered in any convenient dosage form including, for example, capsule, tablet, liquid, suspension, and the like.
Generally, an effective p-glycoprotein inhibiting amount of a p-glycoprotein inhibitor is that amount which is effective in providing inhibition of the activity of the p-glycoprotein mediated active transport system present in the gut. An effective p-glycoprotein inhibiting amount can vary between about 5 mg to about 1000 mg of p-glycoprotein inhibitor as a daily dose depending upon the particular p-glycoprotein inhibitor selected, the species of patient to be treated, the dosage regimen, and other factors which are all well within the abilities of one of ordinary skill in the medical arts to evaluate and assess. A preferred amount however will typically be from about 50 mg to about 500 mg, and a more preferred amount will typically be from about 100 mg to about 500 mg. The above amounts of a p-glycoprotein inhibitor can be administered from once to multiple times per day. Typically for oral dosing, doses will be administered on a regimen requiring one, two or three doses per day.
Where water soluble vitamin E or a polyethylene glycol is selected as the p-glycoprotein inhibitor, a preferred amount will typically be from about 5 mg to about 1000 mg, a more preferred amount will typically be from about 50 mg to about 500 mg, and a further preferred amount will typically be from about 100 mg to about 500 mg. The most preferred amount of water soluble vitamin E or a polyethylene glycol will be from about 200 mg to about 500 mg. The above amounts of water soluble vitamin E or polyethylene glycol can be administered from once to multiple times per day. Typically, doses will be administered on a regimen requiring one, two or three doses per day with one and two being preferred.
As used herein, the term “co-administration” refers to administration to a patient of both a compound that has vasodilating and/or platelet aggregation inhibiting properties, including the compounds described in U.S. Pat. Nos. 4,306,075 and 5,153,222 which include treprostinil and structures I and II described herein, and a p-glycoprotein inhibitor so that the pharmacologic effect of the p-glycoprotein inhibitor in inhibiting p-glycoprotein mediated transport in the gut is manifest at the time at which the compound is being absorbed from the gut. Of course, the compound and the p-glycoprotein inhibitor may be administered at different times or concurrently. For example, the p-glycoprotein inhibitor may be administered to the patient at a time prior to administration of the therapeutic compound so as to pre-treat the patient in preparation for dosing with the vasodilating compound. Furthermore, it may be convenient for a patient to be pre-treated with the p-glycoprotein inhibitor so as to achieve steady state levels of p-glycoprotein inhibitor prior to administration of the first dose of the therapeutic compound. It is also contemplated that the vasodilating and/or platelet aggregation inhibiting compounds and the p-glycoprotein inhibitor may be administered essentially concurrently either in separate dosage forms or in the same oral dosage form.
The present invention further provides that the vasodilating and/or platelet aggregation inhibiting compound and the p-glycoprotein inhibitor may be administered in separate dosage forms or in the same combination oral dosage form. Co-administration of the compound and the p-glycoprotein inhibitor may conveniently be accomplished by oral administration of a combination dosage form containing both the compound and the p-glycoprotein inhibitor.
Thus, an additional embodiment of the present invention is a combination pharmaceutical composition for oral administration comprising an effective vasodilating and/or platelet aggregation inhibiting amount of a compound described herein and an effective p-glycoprotein inhibiting amount of a p-glycoprotein inhibitor. This combination oral dosage form may provide for immediate release of both the vasodilating and/or platelet aggregation inhibiting compound and the p-glycoprotein inhibitor or may provide for sustained release of one or both of the vasodilating and/or platelet aggregation inhibiting compound and the p-glycoprotein inhibitor. One skilled in the art would readily be able to determine the appropriate properties of the combination dosage form so as to achieve the desired effect of co-administration of the vasodilating and/or platelet aggregation inhibiting compound and the p-glycoprotein inhibitor.
Accordingly, the present invention provides for an enhancement of the bioavailability of treprostinil, a drug of structure I or II, and pharmaceutically acceptable salts thereof by co-administration of a p-glycoprotein inhibitor. By co-administration of these compounds and a p-glycoprotein inhibitor, the total amount of the compound can be increased over that which would otherwise circulate in the blood in the absence of the p-glycoprotein inhibitor. Thus, co-administration in accordance with the present invention can cause an increase in the AUC of the present compounds over that seen with administration of the compounds alone.
Typically, bioavailability is assessed by measuring the drug concentration in the blood at various points of time after administration of the drug and then integrating the values obtained over time to yield the total amount of drug circulating in the blood. This measurement, called the Area Under the Curve (AUC), is a direct measurement of the bioavailability of the drug.
Without limiting the scope of the invention, it is believed that in some embodiments derivatizing treprostinil at the R 2 and R 3 hydroxyl groups can help overcome the barriers to oral treprostinil delivery by blocking these sites, and thus the metabolism rate may be reduced to permit the compound to bypass some of the first pass effect. Also, with an exposed amino acid, the prodrug may be actively absorbed from the dipeptide transporter system that exists in the gastrointestinal tract. Accordingly, the present invention provides compounds, such as those found in structures I and II, that reduce the first pass effect of treprostinil and/or reduce the efflux mechanism of the gastrointestinal tract.
In some embodiments of the method of treating hypertension in a subject, the subject is a mammal, and in some embodiments is a human.
Pharmaceutical formulations may include any of the compounds of any of the embodiments described above, either alone or in combination, in combination with a pharmaceutically acceptable carrier such as those described herein.
The instant invention also provides for compositions which may be prepared by mixing one or more compounds of the instant invention, or pharmaceutically acceptable salts thereof, with pharmaceutically acceptable carriers, excipients, binders, diluents or the like, to treat or ameliorate a variety of disorders related vasoconstriction and/or platelet aggregation. A therapeutically effective dose further refers to that amount of one or more compounds of the instant invention sufficient to result in amelioration of symptoms of the disorder. The pharmaceutical compositions of the instant invention can be manufactured by methods well known in the art such as conventional granulating, mixing, dissolving, encapsulating, lyophilizing, emulsifying or levigating processes, among others. The compositions can be in the form of, for example, granules, powders, tablets, capsules, syrup, suppositories, injections, emulsions, elixirs, suspensions or solutions. The instant compositions can be formulated for various routes of administration, for example, by oral administration, by transmucosal administration, by rectal administration, transdermal or subcutaneous administration as well as intrathecal, intravenous, intramuscular, intraperitoneal, intranasal, intraocular or intraventricular injection. The compound or compounds of the instant invention can also be administered by any of the above routes, for example in a local rather than a systemic fashion, such as injection as a sustained release formulation. The following dosage forms are given by way of example and should not be construed as limiting the instant invention.
For oral, buccal, and sublingual administration, powders, suspensions, granules, tablets, pills, capsules, gelcaps, and caplets are acceptable as solid dosage forms. These can be prepared, for example, by mixing one or more compounds of the instant invention, or pharmaceutically acceptable salts thereof, with at least one additive or excipient such as a starch or other additive. Suitable additives or excipients are sucrose, lactose, cellulose sugar, mannitol, maltitol, dextran, sorbitol, starch, agar, alginates, chitins, chitosans, pectins, tragacanth gum, gum arabic, gelatins, collagens, casein, albumin, synthetic or semi-synthetic polymers or glycerides, methyl cellulose, hydroxypropylmethyl-cellulose, and/or polyvinylpyrrolidone. Optionally, oral dosage forms can contain other ingredients to aid in administration, such as an inactive diluent, or lubricants such as magnesium stearate, or preservatives such as paraben or sorbic acid, or anti-oxidants such as ascorbic acid, tocopherol or cysteine, a disintegrating agent, binders, thickeners, buffers, sweeteners, flavoring agents or perfuming agents. Additionally, dyestuffs or pigments may be added for identification. Tablets may be further treated with suitable coating materials known in the art.
Additionally, tests have shown that the present compounds, including treprostinil, and in particular the compounds of structure I and II have increased bioavailability when delivered to the duodenum. Accordingly, one embodiment of the present invention involves preferential delivery of the desired compound to the duodenum as well as pharmaceutical formulations that achieve duodenal delivery. Duodenal administration can be achieved by any means known in the art. In one of these embodiments, the present compounds can be formulated in an enteric-coated dosage form. Generally, enteric-coated dosage forms are usually coated with a polymer that is not soluble at low pH, but dissolves quickly when exposed to pH conditions of 3 or above. This delivery form takes advantage of the difference in pH between the stomach, which is about 1 to 2, and the duodenum, where the pH tends to be greater than 4.
Liquid dosage forms for oral administration may be in the form of pharmaceutically acceptable emulsions, syrups, elixirs, suspensions, slurries and solutions, which may contain an inactive diluent, such as water. Pharmaceutical formulations may be prepared as liquid suspensions or solutions using a sterile liquid, such as, but not limited to, an oil, water, an alcohol, and combinations of these. Pharmaceutically suitable surfactants, suspending agents, emulsifying agents, may be added for oral or parenteral administration.
As noted above, suspensions may include oils. Such oil include, but are not limited to, peanut oil, sesame oil, cottonseed oil, corn oil and olive oil. Suspension preparation may also contain esters of fatty acids such as ethyl oleate, isopropyl myristate, fatty acid glycerides and acetylated fatty acid glycerides. Suspension formulations may include alcohols, such as, but not limited to, ethanol, isopropyl alcohol, hexadecyl alcohol, glycerol and propylene glycol. Ethers, such as but not limited to, poly(ethyleneglycol), petroleum hydrocarbons such as mineral oil and petrolatum; and water may also be used in suspension formulations.
Injectable dosage forms generally include aqueous suspensions or oil suspensions which may be prepared using a suitable dispersant or wetting agent and a suspending agent. Injectable forms may be in solution phase or in the form of a suspension, which is prepared with a solvent or diluent. Acceptable solvents or vehicles include sterilized water, Ringer's solution, or an isotonic aqueous saline solution. Alternatively, sterile oils may be employed as solvents or suspending agents. Preferably, the oil or fatty acid is non-volatile, including natural or synthetic oils, fatty acids, mono-, di- or tri-glycerides.
For injection, the pharmaceutical formulation may be a powder suitable for reconstitution with an appropriate solution as described above. Examples of these include, but are not limited to, freeze dried, rotary dried or spray dried powders, amorphous powders, granules, precipitates, or particulates. For injection, the formulations may optionally contain stabilizers, pH modifiers, surfactants, bioavailability modifiers and combinations of these. The compounds may be formulated for parenteral administration by injection such as by bolus injection or continuous infusion. A unit dosage form for injection may be in ampoules or in multi-dose containers.
Besides those representative dosage forms described above, pharmaceutically acceptable excipients and carries are generally known to those skilled in the art and are thus included in the instant invention. Such excipients and carriers are described, for example, in “Remingtons Pharmaceutical Sciences” Mack Pub. Co., New Jersey (1991), which is incorporated herein by reference.
The formulations of the invention may be designed for to be short-acting, fast-releasing, long-acting, and sustained-releasing as described below. Thus, the pharmaceutical formulations may also be formulated for controlled release or for slow release.
The instant compositions may also comprise, for example, micelles or liposomes, or some other encapsulated form, or may be administered in an extended release form to provide a prolonged storage and/or delivery effect. Therefore, the pharmaceutical formulations may be compressed into pellets or cylinders and implanted intramuscularly or subcutaneously as depot injections or as implants such as stents. Such implants may employ known inert materials such as silicones and biodegradable polymers.
Specific dosages may be adjusted depending on conditions of disease, the age, body weight, general health conditions, sex, and diet of the subject, dose intervals, administration routes, excretion rate, and combinations of drugs. Any of the above dosage forms containing effective amounts are well within the bounds of routine experimentation and therefore, well within the scope of the instant invention.
A therapeutically effective dose may vary depending upon the route of administration and dosage form. The preferred compound or compounds of the instant invention is a formulation that exhibits a high therapeutic index. The therapeutic index is the dose ratio between toxic and therapeutic effects which can be expressed as the ratio between LD 50 and ED 50 . The LD 50 is the dose lethal to 50% of the population and the ED 50 is the dose therapeutically effective in 50% of the population. The LD 50 and ED 50 are determined by standard pharmaceutical procedures in animal cell cultures or experimental animals.
A method of preparing pharmaceutical formulations includes mixing any of the above-described compounds with a pharmaceutically acceptable carrier and water or an aqueous solution.
Pharmaceutical formulations and medicaments according to the invention include any of the compounds of any of the embodiments of compound of structure I, II or pharmaceutically acceptable salts thereof described above in combination with a pharmaceutically acceptable carrier. Thus, the compounds of the invention may be used to prepare medicaments and pharmaceutical formulations. In some such embodiments, the medicaments and pharmaceutical formulations comprise any of the compounds of any of the embodiments of the compounds of structure I or pharmaceutically acceptable salts thereof. The invention also provides for the use of any of the compounds of any of the embodiments of the compounds of structure I, II or pharmaceutically acceptable salts thereof for prostacyclin-like effects. The invention also provides for the use of any of the compounds of any of the embodiments of the compounds of structure I, II or pharmaceutically acceptable salts thereof or for the treatment of pulmonary hypertension.
The invention also pertains to kits comprising one or more of the compounds of structure I or II along with instructions for use of the compounds. In another embodiment, kits having compounds with prostacyclin-like effects described herein in combination with one or more p-glycoprotein inhibitors is provided along with instructions for using the kit.
By way of illustration, a kit of the invention may include one or more tablets, capsules, caplets, gelcaps or liquid formulations containing the bioenhancer of the present invention, and one or more tablets, capsules, caplets, gelcaps or liquid formulations containing a prostacyclin-like effect compound described herein in dosage amounts within the ranges described above. Such kits may be used in hospitals, clinics, physician's offices or in patients' homes to facilitate the co-administration of the enhancing and target agents. The kits should also include as an insert printed dosing information for the co-administration of the enhancing and target agents.
The following abbreviations and definitions are used throughout this application:
Generally, reference to a certain element such as hydrogen or H is meant to include all isotopes of that element. For example, if an R group is defined to include hydrogen or H, it also includes deuterium and tritium.
As used herein, the term “p-glycoprotein inhibitor” refers to organic compounds which inhibit the activity of the p-glycoprotein mediated active transport system present in the gut. This transport system actively transports drugs which have been absorbed from the intestinal lumen and into the gut epithelium back out into the lumen. Inhibition of this p-glycoprotein mediated active transport system will cause less drug to be transported back into the lumen and will thus increase the net drug transport across the gut epithelium and will increase the amount of drug ultimately available in the blood.
The phrases “oral bioavailability” and “bioavailability upon oral administration” as used herein refer to the systemic availability (i.e., blood/plasma levels) of a given amount of drug administered orally to a patient.
The phrase “unsubstituted alkyl” refers to alkyl groups that do not contain heteroatoms. Thus the phrase includes straight chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and the like. The phrase also includes branched chain isomers of straight chain alkyl groups, including but not limited to, the following which are provided by way of example: —CH(CH 3 ) 2 , —CH(CH 3 )(CH 2 CH 3 ), —CH(CH 2 CH 3 ) 2 , —C(CH 3 ) 3 , —C(CH 2 CH 3 ) 3 , —CH 2 CH(CH 3 ) 2 , —CH 2 CH(CH 3 )(CH 2 CH 3 ), —CH 2 CH(CH 2 CH 3 ) 2 , —CH 2 C(CH 3 ) 3 , —CH 2 C(CH 2 CH 3 ) 3 , —CH(CH 3 )CH(CH 3 )(CH 2 CH 3 ), —CH 2 CH 2 CH(CH 3 ) 2 , —CH 2 CH 2 CH(CH 3 )(CH 2 CH 3 ), —CH 2 CH 2 CH(CH 2 CH 3 ) 2 , —CH 2 CH 2 C(CH 3 ) 3 , —CH 2 CH 2 C(CH 2 CH 3 ) 3 , —CH(CH 3 )CH 2 CH(CH 3 ) 2 , —CH(CH 3 )CH(CH 3 )CH(CH 3 ) 2 , —CH(CH 2 CH 3 )CH(CH 3 )CH(CH 3 )(CH 2 CH 3 ), and others. The phrase also includes cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl and such rings substituted with straight and branched chain alkyl groups as defined above. The phrase also includes polycyclic alkyl groups such as, but not limited to, adamantyl norbornyl, and bicyclo[2.2.2]octyl and such rings substituted with straight and branched chain alkyl groups as defined above. Thus, the phrase unsubstituted alkyl groups includes primary alkyl groups, secondary alkyl groups, and tertiary alkyl groups. Unsubstituted alkyl groups may be bonded to one or more carbon atom(s), oxygen atom(s), nitrogen atom(s), and/or sulfur atom(s) in the parent compound. Preferred unsubstituted alkyl groups include straight and branched chain alkyl groups and cyclic alkyl groups having 1 to 20 carbon atoms. More preferred such unsubstituted alkyl groups have from 1 to 10 carbon atoms while even more preferred such groups have from 1 to 5 carbon atoms. Most preferred unsubstituted alkyl groups include straight and branched chain alkyl groups having from 1 to 3 carbon atoms and include methyl, ethyl, propyl, and —CH(CH 3 ) 2 .
The phrase “substituted alkyl” refers to an unsubstituted alkyl group as defined above in which one or more bonds to a carbon(s) or hydrogen(s) are replaced by a bond to non-hydrogen and non-carbon atoms such as, but not limited to, a halogen atom in halides such as F, Cl, Br, and I; and oxygen atom in groups such as hydroxyl groups, alkoxy groups, aryloxy groups, and ester groups; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfone groups, sulfonyl groups, and sulfoxide groups; a nitrogen atom in groups such as amines, amides, alkylamines, dialkylamines, arylamines, alkylarylamines, diarylamines, N-oxides, imides, and enamines; a silicon atom in groups such as in trialkylsilyl groups, dialkylarylsilyl groups, alkyldiarylsilyl groups, and triarylsilyl groups; and other heteroatoms in various other groups. Substituted alkyl groups also include groups in which one or more bonds to a carbon(s) or hydrogen(s) atom is replaced by a bond to a heteroatom such as oxygen in carbonyl, carboxyl, and ester groups; nitrogen in groups such as imines, oximes, hydrazones, and nitriles. Preferred substituted alkyl groups include, among others, alkyl groups in which one or more bonds to a carbon or hydrogen atom is/are replaced by one or more bonds to fluorine atoms. One example of a substituted alkyl group is the trifluoromethyl group and other alkyl groups that contain the trifluoromethyl group. Other alkyl groups include those in which one or more bonds to a carbon or hydrogen atom is replaced by a bond to an oxygen atom such that the substituted alkyl group contains a hydroxyl, alkoxy, aryloxy group, or heterocyclyloxy group. Still other alkyl groups include alkyl groups that have an amine, alkylamine, dialkylamine, arylamine, (alkyl)(aryl)amine, diarylamine, heterocyclylamine, (alkyl)(heterocyclyl)amine, (aryl)(heterocyclyl)amine, or diheterocyclylamine group.
The phrase “unsubstituted arylalkyl” refers to unsubstituted alkyl groups as defined above in which a hydrogen or carbon bond of the unsubstituted alkyl group is replaced with a bond to an aryl group as defined above. For example, methyl (—CH 3 ) is an unsubstituted alkyl group. If a hydrogen atom of the methyl group is replaced by a bond to a phenyl group, such as if the carbon of the methyl were bonded to a carbon of benzene, then the compound is an unsubstituted arylalkyl group (i.e., a benzyl group). Thus the phrase includes, but is not limited to, groups such as benzyl, diphenylmethyl, and 1-phenylethyl (—CH(C 6 H 5 )(CH 3 )) among others.
The phrase “substituted arylalkyl” has the same meaning with respect to unsubstituted arylalkyl groups that substituted aryl groups had with respect to unsubstituted aryl groups. However, a substituted arylalkyl group also includes groups in which a carbon or hydrogen bond of the alkyl part of the group is replaced by a bond to a non-carbon or a non-hydrogen atom. Examples of substituted arylalkyl groups include, but are not limited to, —CH 2 C(═O)(C 6 H 5 ), and —CH 2 (2-methylphenyl) among others.
A “pharmaceutically acceptable salt” includes a salt with an inorganic base, organic base, inorganic acid, organic acid, or basic or acidic amino acid. As salts of inorganic bases, the invention includes, for example, alkali metals such as sodium or potassium; alkaline earth metals such as calcium and magnesium or aluminum; and ammonia. As salts of organic bases, the invention includes, for example, trimethylamine, triethylamine, pyridine, picoline, ethanolamine, diethanolamine, and triethanolamine. As salts of inorganic acids, the instant invention includes, for example, hydrochloric acid, hydroboric acid, nitric acid, sulfuric acid, and phosphoric acid. As salts of organic acids, the instant invention includes, for example, formic acid, acetic acid, trifluoroacetic acid, fumaric acid, oxalic acid, lactic acid, tartaric acid, maleic acid, citric acid, succinic acid, malic acid, methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. As salts of basic amino acids, the instant invention includes, for example, arginine, lysine and ornithine. Acidic amino acids include, for example, aspartic acid and glutamic acid.
“Treating” within the context of the instant invention, means an alleviation of symptoms associated with a biological condition, disorder, or disease, or halt of further progression or worsening of those symptoms, or prevention or prophylaxis of the disease or disorder. For example, within the context of treating patients having pulmonary hypertension, successful treatment may include a reduction direct vasodilation of pulmonary and/or systemic arterial vascular beds and inhibition of platelet aggregation. The result of this vasodilation will generally reduce right and left ventricular afterload and increased cardiac output and stroke volume. Dose-related negative inotropic and lusitropic effects can also result. The outward manifestation of these physical effects can include a decrease in the symptoms of hypertension, such as shortness of breath, and an increase in exercise capacity.
The present invention, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present invention.
EXAMPLES
Example 1
In this Example, the bioavailability of treprostinil in rats after dosing orally, intraduodenally, intracolonically and via the portal vein was compared to determine possible barriers to bioavailability. In addition to bioavailability, a number of pharmacokinetic parameters were determined.
Animal Dosing
The bioavailability of treprostinil was evaluated in Sprague-Dawley, male rats. Fifteen surgically modified rats were purchased from Hilltop Lab Animals (Scottdale, Pa.). The animals were shipped from Hilltop to Absorption Systems' West Chester University facility (West Chester, Pa.), where they were housed for at least twenty-four hours prior to being used in the study. The animals were fasted for approximately 16 hours prior to dosing. The fifteen rats used in this study were divided into five groups (I, II, III, IV and V).
The weight of the animals and the dosing regimen are presented in Table 1.
TABLE 1
Dose
Rat
Weight
Route of
Study
Volume
Dose
Group
#
(g)
Administration
Day
(mL/kg)
(mg/kg)
I
118
327
Intravenous
0
2
1
119
329
Intravenous
0
2
1
120
320
Intravenous
0
2
1
II
121
337
Intraportal Vein
0
2
1
122
319
Intraportal Vein
0
2
1
123
330
Intraportal Vein
0
2
1
III
124
329
Intraduodenal
0
2
1
125
331
Intraduodenal
0
2
1
126
324
Intraduodenal
0
2
1
IV
127
339
Intracolonic
0
2
1
128
333
Intracolonic
0
2
1
129
320
Intracolonic
0
2
1
V
130
293
Oral
0
2
1
131
323
Oral
0
2
1
132
332
Oral
0
2
1
Samples were withdrawn at the following time points.
IV and IPV: 0 (pre-dose) 2, 5, 15, 30, 60, 120, 240, 360, 480 minutes
ID, IC and Oral: 0 (pre-dose), 5, 15, 30, 60, 120, 240, 360, 480 minutes
Approximately 0.50 to 0.75 mL of whole blood was collected from the jugular vein of a cannulated rat. The blood was transferred to heparinized tubes and placed on ice until centrifuged. Following centrifugation the plasma was placed on ice until frozen at −70□C prior to shipment to Absorption Systems
Analysis of Plasma Samples
Samples were analyzed using the following methodology:
Dosing Solution Preparation
The dosing solution was prepared by combining 15.2 mg of treprostinil diethanolamine (12.0 mg of the free acid form) with 24 mL of 5% dextrose. The solution was then sonicated until dissolved for a final concentration of 0.5 mg/mL. The final pH of the dosing solution was 4.6. At the time of dosing, the dosing solution was clear and homogenous.
Standards and Sample Preparation
To determine the concentration of treprostinil in rat plasma samples, standards were prepared with rat plasma collected in heparin obtained from Lampire Biological Laboratories (Lot #021335263) to contain 1000, 300, 100, 30, 10, 3, 1 and 0.3 ng/mL of treprostinil. Plasma standards were treated identically to the plasma samples.
Plasma samples were prepared by solid phase extraction. After an extraction plate was equilibrated, 150 μL of a plasma sample was placed into the well and vacuumed through. The extraction bed was then washed with 600 μL of acetonitrile: deionized water (25:75) with 0.2% formic acid. The compound was eluted with 600 μL of 90% acetonitrile and 10% ammonium acetate. The eluates were collected and evaporated to dryness. The residue was reconstituted with 150 μL of acetonitrile: deionized water (50:50) with 0.5 μg/mL of tolbutamide (used as an internal standard).
HPLC Conditions
Column: Keystone Hypersil BDS C18 30×2 mm i.d., 3 μm.
Mobile Phase Buffer: 25 mM NH 4 OH to pH 3.5 w/85% formic acid.
Reservoir A: 10% buffer and 90% water.
Reservoir B: 10% buffer and 90% acetonitrile.
Mobile Phase Composition:
Gradient Program:
Time
Duration
Grad. Curve
% A
% B
−0.1
0.10
0
80
20
0
3.00
1.0
10
90
3.00
1.00
1.0
0
100
4.00
2.00
0
80
20
Flow Rate: 300 μL/min.
Inj. Vol.: 10 μL
Run Time: 6.0 min.
Retention Time: 2.6 min.
Mass Spectrometer
Instrument: PE SCIEX API 2000
Interface: Electrospray (“Turbo Ion Spray”)
Mode: Multiple Reaction Monitoring (MRM)
Precursor Ion
Product Ion
Treprostinil
389.2
331.2
IS
269.0
170.0
Nebulizing Gas: 25 Drying Gas: 60, 350° C. Curtain Gas: 25 Ion Spray: −5000 V Orifice: −80 V Ring: −350 V Q0: 10 V IQ1: 11 V ST: 15 V R01: 11 V IQ2: 35 V R02: 40 V IQ3: 55 V R03: 45 V CAD Gas: 4
Method Validation
Table 2 lists the average recoveries (n=6) and coefficient of variation (c.v.) for rat plasma spiked with treprostinil. All samples were compared to a standard curve prepared in 50:50 dH 2 O:acetonitrile with 0.5 μg/mL of tolbutamide to determine the percent of treprostinil recovered from the plasma.
TABLE 2 Accuracy and Precision of Method Spiked Coefficient of Concentration Percent Recovered Variation 1000 ng/mL 85.6 5.2 100 ng/mL 89.6 11.6 10 ng/mL 98.8 7.0
Pharmacokinetic Analysis
Pharmacokinetic analysis was performed on the average plasma concentration for each time point.
The data were subjected to non-compartmental analysis using the pharmacokinetic program WinNonlin v. 3.1 (2).
Results
Clinical Observations
Prior to beginning the experiments it was noted that supra-pharmacological doses of treprostinil would be needed to achieve plasma concentrations that could be analyzed with adequate sensitivity. Using the dose of 1 mg/kg some adverse effects were noted in animals dosed intravenously and via the intraportal vein.
All rats dosed intravenously displayed signs of extreme lethargy five minutes after dosing but fully recovered to normal activity thirty minutes post-dosing. In addition, fifteen minutes after dosing all three animals dosed via the portal vein exhibited signs of lethargy. One rat (#123) expired before the thirty-minute sample was drawn. The other rats fully recovered. The remaining animals did not display any adverse reactions after administration of the compound.
Sample Analysis
Average plasma concentrations for each route of administration are shown in Table 3.
TABLE 3
Average (n = 3) plasma concentrations (ng/mL)
Pre-
Time (min)
dose
2
5
15
30
60
120
240
360
480
Intravenous
0
1047.96
364.28
130.91
55.56
14.45
4.45
1.09
0.50
0.30
Intraportal Vein*
0
302.28
97.39
47.98
21.94
11.06
3.87
2.51
4.95
5.14
Intraduodenal
0
—
61.76
31.67
18.57
13.55
5.91
1.11
0.89
0.90
Intracolonic
0
—
7.46
3.43
3.52
1.48
0.64
0.36
0.06 λ
0.20 λ
Oral
0
—
4.52
2.90
3.67
2.06
4.52
1.82
0.90
0.96
*n = 2,
λ concentration falls below the limit of quantitation (LOQ) of the analytical method
The plasma concentration versus time curves for intravenous, intraportal, intraduodenal, intracolonic and oral dosing are shown in FIGS. 1 and 2 . FIG. 3 shows the average plasma concentration versus time curves for all five routes of administration. In the experiments shown in these figures, the diethanolamine salt was used. Table 4 shows the pharmacokinetic parameters determined for treprostinil. The individual bioavailabilities of each rat are found in Table 5.
TABLE 4
Average Bioavailability and Pharmacokinetic Parameters of Treprostinil in Rats
Average
Average
Volume of
CLs
Route of
AUC 480 min
C max
T max
T 1/2
Bioavailability
Distribution*
(mL · min −1 ·
Administration
(min · ng/mL)
(ng/mL)
(min)
(min)
(%) ± SD
(L · kg −1 )
kg −1 )*
Intravenous
11253.49
2120 ψ
0
94
NA
1.98
88.54
Intraportal Vein
4531.74
302
2
ND
40.3 ± 5.5
ND
ND
Intraduodenal
2712.55
62
5
ND
24.1 ± 0.5
ND
ND
Intracolonic
364.63
8
5
ND
3.2 ± 2.5
ND
ND
Oral
1036.23
5
5
ND
9.2 ± 1.4
ND
ND
*Normalized to the average weight of the rats
ND: Not determined
ψ Extrapolated Value
TABLE 5
Individual Bioavailabilities of Treprostinil in Rats
Route of
Individual AUC 480 min
Individual
Administration
Rat #
(min · ng/mL)
Bioavailability (%)
Intravenous
118
10302.85
NA
119
9981.52
NA
120
13510.65
NA
Intraportal Vein
121
4970.67
44.2
122
4093.21
36.4
123
ND
ND
Intraduodenal
124
2725.68
24.2
125
2763.60
24.6
126
2646.05
23.5
Intracolonic
127
72.63
0.7
128
395.08
3.5
129
625.20
5.6
Oral
130
998.70
8.9
131
907.60
8.1
132
1203.73
10.7
NA: Not applicable
ND: Not determined
Conclusions
Treprostinil has a terminal plasma half-life of 94 minutes. The distribution phase of treprostinil has a half-life of 10.3 minutes and over 90% of the distribution and elimination of the compound occurs by 60 minutes post-dosing. The volume of distribution (Vd=1.98 L/kg) is greater than the total body water of the rat (0.67 L/kg) indicating extensive partitioning into tissues. The systemic clearance of treprostinil (88.54 mL/min/kg) is greater than the hepatic blood flow signifying that extra-hepatic clearance mechanisms are involved in the elimination of the compound.
First pass hepatic elimination of treprostinil results in an average intraportal vein bioavailability of 40.3%. Fast but incomplete absorption is observed after intraduodenal, intracolonic and oral dosing (T max ≦5 min). By comparing the intraportal vein (40.3%) and intraduodenal bioavailability (24.1%) it appears that approximately 60% of the compound is absorbed in the intestine. The average intraduodenal bioavailibility is almost three times greater than the oral bioavailibility suggesting that degradation of treprostinil in the stomach or gastric emptying may influence the extent of systemic absorption.
Example 2
In this Example, Treprostinil concentrations were determined in male Sprague-Dawley rats following a single oral dose of the following compounds:
Experimental
Dosing Solution Preparation
All dosing vehicles were prepared less than 2 hours prior to dosing.
1. Treprostinil Methyl Ester
A solution of treprostinil methyl ester was prepared by dissolving 2.21 mg of treprostinil methyl ester with 0.85 mL of dimethylacetamide (DMA). This solution was then diluted with 7.65 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.26 mg/mL of treprostinil methyl ester equivalent to 0.25 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
2. Treprostinil Benzyl Ester
A solution of treprostinil benzyl ester was prepared by dissolving 2.58 mg of treprostinil benzyl ester with 0.84 mL of dimethylacetamide (DMA). This solution was then diluted with 7.54 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.268 mg/mL of treprostinil benzyl ester equivalent to 0.25 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
3. Treprostinil Diglycine
A solution of treprostinil diglycine was prepared by dissolving 1.86 mg of compound with 0.58 mL of dimethylacetamide (DMA). This solution was then diluted with 5.18 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.323 mg/mL of treprostinil diglycine equivalent to 0.25 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
Animal Dosing
The plasma concentrations of Treprostinil following administration of each prodrug were evaluated in male Sprague-Dawley rats. Rats were purchased from Hilltop Lab Animals (Scottdale, Pa.). The animals were shipped from Hilltop to Absorption Systems' West Chester University facility (West Chester, Pa.). They were housed for at least twenty-four hours prior to being used in the study. The animals were fasted for approximately 16 hours prior to dosing. The rats used in this study were divided into three groups (I, II and III). Groups I-III were dosed on the same day.
The weight of the animals and the dosing regimen are presented in Table 6.
TABLE 6
Study Design
Route of
Dose
Rat
Weight
Adminis-
Compound
Volume
Dose*
Group
#
(kg)
tration
Dosed
(mL/kg)
(mg/kg)
I
638
306
Oral
Treprostinil
2
0.520
639
310
Oral
methyl ester
640
319
Oral
II
641
319
Oral
Treprostinil
2
0.616
642
309
Oral
benzyl ester
643
320
Oral
III
644
318
Oral
Treprostinil
2
0.646
645
313
Oral
diglycine
646
322
Oral
*This dose of prodrug = 0.500 mg/kg of the active, Treprostinil
Animals were dosed via oral gavage. Blood samples were taken from a jugular vein cannula at the following time points:
0 (pre-dose) 5, 15, 30, 60, 120, 240, 360 and 480 minutes
The blood samples were withdrawn and placed into tubes containing 30 μL of a solution of 500 units per mL of heparin in saline, and centrifuged at 13,000 rpm for 10 minutes. Approximately 200 μL of plasma was then removed and dispensed into approperiately labeled polypropylene tubes containing 4 μL of acetic acid in order to stabilize any prodrug remaining in the samples. The plasma samples were frozen at −20° C. and were transported on ice to Absorption Systems Exton Facility. There they were stored in a −80° C. freezer pending analysis.
Analysis of Plasma Samples
Plasma samples were analyzed as described in Example 1. In brief, Treprostinil was extracted from the plasma via liquid-liquid extraction then analyzed by LC/MS/MS. The analytical validation results were reported previously in Example 1. The lower limit of quantification (LLOQ) of the analytical method was 0.01 ng/mL. Samples were not assayed for unchanged prodrug.
Acceptance Criteria for Analytical Runs
Two standard curves, with a minimum of five points per curve, and a minimum of two quality control samples (QCs) were dispersed throughout each run. Each route of administration was bracketed by a standard curve used for back-calculation. The standards and QCs must be within ±15% (20% for the LLOQ) accuracy and precision for the run to be accepted. At least 75% of all standards and QCs must pass the acceptance criteria.
Pharmacokinetic Analysis
Pharmacokinetic analysis was performed on the plasma concentration of Treprostinil for each individual rat at each time point and on the average plasma concentration for all three rats in the group for each time point. The data were subjected to non-compartmental analysis using the pharmacokinetic program WinNonLin v. 3.1 (2).
Results
Study Observations
No adverse reactions were observed following oral administration of treprostinil methyl ester, treprostinil benzyl ester or treprostinil diglycine.
Plasma Stability of Prodrugs in Acidified Rat Plasma
In order to terminate any conversion of prodrug to active after samples were withdrawn the plasma was acidified. Acetic acid (v/v) was added to each plasma sample immediately after centrifugation of the red blood cells to a concentration of 2%. In-vitro plasma stability of each prodrug was performed to insure that the compound was stable in acidified plasma. To perform this assay 2% acetic acid was added to blank rat plasma obtained from Lampire Biological. The acidified rat plasma was equilibrated at 37° C. for three minutes prior to addition of prodrug. The initial concentration of each prodrug was 1000 ng/mL. A 100 μL aliquot of plasma (n=3 per time point) was taken at 0, 60 and 120 minutes. Each aliquot was combined with 20 μL of HCl and vortexed. Liquid-liquid extraction was then performed and the concentration of Treprostinil in each sample determined. The concentration of Treprostinil at each time point in acidified rat plasma is given in Table 7. Small amounts of Treprostinil appear to be present in the neat compound sample of treprostinil ester and treprostinil diglycine. The concentration of Treprostinil remained constant throughout the course of the experiment, indicating that there was no conversion prodrug into active compound occurring in acidified plasma.
TABLE 7
Plasma Stability of Prodrugs in Acidified Dog Plasma
Treprostinil Concentration
(ng/mL) ± SD (n = 3)
Treprostinil
Treprostinil
Treprostinil
Time (min)
methyl ester
benzyl ester
diglycine
0
56.8 ± 9.3
<0.01
54.9 ± 4.3
60
55.1 ± 5.0
<0.01
51.8 ± 5.9
120
53.8 ± 1.3
<0.01
54.5 ± 0.8
Total % Treprostinil
5.7
<0.01
5.5
Average Treprostinil plasma concentrations following administration of treprostinil methyl ester, treprostinil benzyl ester or treprostinil diglycine are shown in Table 8.
TABLE 8
Treprostinil Concentrations (Average ± SD (n = 3) Plasma Concentrations (ng/mL)
Oral Dosing
Pre-
5
15
30
60
120
240
360
480
Solution
Dose
(min)
(min)
(min)
(min)
(min)
(min)
(min)
(min)
Treprostinil
0
<0.01
0.2 ± 0.0
0.3 ± 0.1
0.5 ± 0.1
1.5 ± 0.8
0.2 ± 0.7
<0.01
0.1 ± 0.1
methyl ester
Treprostinil
0
3.1 ± 2.8
1.9 ± 0.8
2.5 ± 1.5
3.2 ± 1.9
7.3 ± 4.9
1.6 ± 1.2
0.4 ± 0.40
0.6 ± 0.9
benzyl ester
Treprostinil
0
<0.01
1.1 ± 1.9
6.6 ± 10.7
0.5 ± 0.3*
40. ± 5.8
9.0 ± 13.5
2.1 ± 2.9
1.3 ± 0.8
diglycine
*Due to insufficient amount of sample collected this time point is the average of n = 2 rats.
FIGS. 4-7 contain graphical representations of the plasma concentration versus time curves for Treprostinil in rat following administration of each prodrug. Table 9 lists each figure and the information displayed.
TABLE 9 List of Figures FIG. Description 4 Oral Dose of Treprostinil methyl ester 5 Oral Dose of Treprostinil benzyl ester 6 Oral Dose of Treprostinil diglycine 7 Oral Dose of Treprostinil benzyl ester and Treprostinil diglycine Compared to Treprostinil Alone from Example 1
Pharmacokinetic Analysis
Bioavailability of the prodrug was determined relative to that of the active compound based on Example 1 in which Treprostinil was dosed to rats. The following formula was used to determine relative bioavailability (F):
Relative F =( AUC (Prodrug Dose) /Dose)/( AUC (Treprostinil Dose) /Dose)*100
Bioavailability was also determined relative to an intravenous dose of Treprostinil in rats determined in Example 1. Results are listed in Table 10.
TABLE 10
Average Relative Bioavailability and Pharmacokinetic Parameters of Treprostinil in Rats
Test
Average
Relative
Compound
Dose
AUC 0-t
C max
T max
Bioavailability
Bioavailability
Administered
(mg/kg)
(min · ng/mL)
(ng/mL)
(min)
(%) ± SD (n = 3)
(%) ± SD (n = 3)
Treprostinil
0.5
212
1.50
120
41.0 ± 16
3.8 ± 2
methyl ester
Treprostinil
0.5
1171
7.20
120
226 ± 155
20.8 ± 14
benzyl ester
Treprostinil
0.5
2242
9.04
240
433 ± 631
39.9 ± 58
diglycine
Conclusions
In this study the relative oral bioavailabilities of prodrugs of Treprostinil were determined in rats. Treprostinil methyl ester resulted in Treprostinil area under the plasma concentration versus time curves (AUCs) less than that after dosing the active compound. Prodrugs treprostinil benzyl ester and treprostinil diglycine both had Treprostinil average AUCs greater than that after dosing of the active compound. Treprostinil diglycine had the highest relative bioavailability of 433% with over 4 times more Treprostinil reaching the systemic circulation. The Cmax of 9 ng/mL of Treprostinil following administration of treprostinil diglycine occurred at 240 minutes post-dosing. The Cmax following dosing of Treprostinil is 5 ng/mL and occurs only 5 minutes post-dosing. Treprostinil benzyl ester had a relative bioavailability of 226±155% with a Cmax of 7.2 ng/mL occurring 120 minutes post-dosing. It should also be noted that the AUCs are not extrapolated to infinity.
References
1. WinNonlin User's Guide, version 3.1, 1998-1999, Pharsight Co., Mountain View, Calif. 94040.
Example 3
This example illustrates a pharmacokinetic study of treprostinil following administration of a single duodenal dose of treprostinil and various prodrugs of the present invention.
In this study, the area under the curve of Treprostinil in male Sprague-Dawley rats following a single intraduodenal dose of treprostinil monophosphate (ring), treprostinil monovaline (ring), treprostinil monoalanine (ring) or treprostinil monoalanine (chain), prodrugs of treprostinil was compared. The compounds were as follows:
having the following substituents:
Compound
R 1
R 2
R 3
treprostinil mono-
H
—PO 3 H 3
H
phosphate (ring)
treprostinil mono-
H
—COCH(CH(CH 3 ) 2 )NH 2
H
valine (ring)
treprostinil mono-
H
—COCH(CH 3 )NH 2
H
alanine (ring)
treprostinil mono-
H
H
—COCH(CH 3 )NH 2
alanine (chain)
Experimental
Dosing Solution Preparation
All dosing vehicles were prepared less than 2 hours prior to dosing.
1. Treprostinil Monophosphate (Ring)
A dosing solution of treprostinil monophosphate (ring) was prepared by dissolving 1.01 mg of treprostinil monophosphate (ring) in 0.167 mL of dimethylacetamide (DMA) until dissolved. This solution was further diluted with 1.50 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.603 mg/mL of prodrug equivalent to 0.5 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
2. Treprostinil Monovaline (Ring)
A 50 mg/mL solution of treprostinil monovaline (ring) was prepared in dimethylacetamide (DMA). A 25 μL aliquot of the 50 mg/mL stock solution was then diluted with 175 μL of DMA and 1.8 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.625 mg/mL of prodrug equivalent to 0.5 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
3. Treprostinil Monoalanine (Ring)
A solution of treprostinil monoalanine (ring) was prepared by dissolving 1.05 mg of treprostinil monoalanine (ring) in 0.178 mL of dimethylacetamide (DMA) until dissolved. This solution was further diluted with 1.60 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.590 mg/mL of treprostinil monoalanine (ring) equivalent to 0.5 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
4. Treprostinil Monoalanine (Chain)
A solution of treprostinil monoalanine (chain) was prepared by dissolving 0.83 mg of treprostinil monoalanine (chain) in 0.14 mL of dimethylacetamide (DMA) until dissolved. This solution was further diluted with 1.26 mL of PEG 400:Polysorbate 80:Water, 40:1:49. The final concentration of the dosing vehicle was 0.591 mg/mL of treprostinil monoalanine (chain) equivalent to 0.5 mg/mL of Treprostinil. The dosing vehicle was a clear solution at the time of dosing.
Animal Dosing
The plasma concentrations of Treprostinil following oral administration of each prodrug were evaluated in male Sprague-Dawley rats. Twelve rats were purchased from Hilltop Lab Animals (Scottdale, Pa.). The animals were shipped from Hilltop to Absorption Systems' West Chester University facility (West Chester, Pa.). They were housed for at least twenty-four hours prior to being used in the study. The animals were fasted for approximately 16 hours prior to dosing. The twelve rats used in this study were divided into four groups. All groups were dosed on day 1 of the study. The weight of the animals and the dosing regimen are presented in Table 11.
TABLE 11
Dose
Rat
Weight
Volume
Dose*
#
(g)
Compound
(mL/kg)
(mg/kg)
130
327
treprostinil monophosphate (ring)
1
0.603
131
321
treprostinil monophosphate (ring)
1
0.603
132
310
treprostinil monophosphate (ring)
1
0.603
133
328
treprostinil monovaline (ring)
1
0.625
134
326
treprostinil monovaline (ring)
1
0.625
135
346
treprostinil monovaline (ring)
1
0.625
136
321
treprostinil monoalanine (chain)
1
0.591
137
319
treprostinil monoalanine (chain)
1
0.591
138
330
treprostinil monoalanine (chain)
1
0.591
139
316
treprostinil monoalanine (ring)
1
0.590
140
330
treprostinil monoalanine (ring)
1
0.590
141
339
treprostinil monoalanine (ring)
1
0.590
*This dose of prodrug = 0.500 mg/kg of treprostinil
Animals were dosed via an indwelling duodenal cannula. Blood samples were takenfrom a jugular vein cannula at the following time points:0 (pre-dose) 5, 15, 30, 60, 120, 240, 360 and 480 minutes.
The blood samples were withdrawn and placed into tubes containing 30 μL of a solution of 500 units per mL of heparin in saline, and centrifuged at 13,000 rpm for 10 minutes. Approximately 200 μL of plasma was then removed and dispensed into appropriately labeled polypropylene tubes containing 4 μL of acetic acid in order to stabilize any prodrug remaining in the samples. The plasma samples were frozen at −20° C. and were transported on ice to Absorption Systems Exton Facility. There they were stored in a −80° C. freezer pending analysis.
Analysis of Plasma Samples
Plasma samples were analyzed using the methods described above. In brief, Treprostinil was extracted from the plasma via solid phase extraction then analyzed by LC/MS/MS. The lower limit of quantification (LLOQ) of the analytical method was 0.03 ng/mL.
Acceptance Criteria for Analytical Runs
Four standard curves, with a minimum of five points per curve, and a minimum of two quality control samples (QCs) at 3 concentrations were dispersed throughout each run. Each prodrug set was bracketed by a standard curve used for back-calculation. The standards and QCs must be within ±15% (20% for the LLOQ) accuracy and precision for the run to be accepted. At least 75% of all standards and QCs must pass the acceptance criteria.
Pharmacokinetic Analysis
Pharmacokinetic analysis was performed on the plasma concentration of Treprostinil for each individual rat at each time point and on the average plasma concentration for all three rats in the group for each time point.
The data were subjected to non-compartmental analysis using the pharmacokinetic program WinNonLin v. 3.1 (2).
Results
Study Observations
No adverse reactions were observed following intraduodenal administration of treprostinil monophosphate (ring), treprostinil monovaline (ring), treprostinil monoalanine (ring) or treprostinil monoalanine (chain).
Ex-Vivo Plasma Stability of Prodrugs in Acidified Rat Plasma
In order to terminate any conversion of prodrug to active after samples were withdrawn, the plasma was acidified. Acetic acid (v/v) was added to each plasma sample immediately after separation of the red blood cells to a concentration of 2%. In-vitro plasma stability of each prodrug was performed to insure that the compound was stable in acidified plasma. To perform this assay 2% acetic acid was added to blank rat plasma obtained from Lampire Biological. The acidified rat plasma was brought to room temperature for three minutes prior to addition of prodrug. The initial concentration of each prodrug was 1000 ng/mL. A 100 μL aliquot of plasma (n=3 per time point) was taken at 0, 60 and 120 minutes. Sample preparation of each plasma sample was performed as described above and the concentration of Treprostinil monitored.
Treprostinil concentrations did not increase in any of the acidified plasma samples spiked with prodrug over the two-hour period of the experiment.
Sample Analysis
Average Treprostinil plasma concentrations following administration of treprostinil monophosphate (ring), treprostinil monovaline (ring), treprostinil monoalanine (ring) or treprostinil monoalanine (chain) are shown in Table 12.
TABLE 12
AVERAGE ± SD (N = 3)
PLASMA TREPROSTINIL CONCENTRATIONS (NG/ML)
Oral Dosing
Pre-
5
15
30
60
120
240
360
480
Solution
dose
(min)
(min)
(min)
(min)
(min)
(min)
(min)
(min)
treprostinil
0
8.62 ± 3.0
6.57 ± 1.7
3.31 ± 1.2
4.31 ± 0.8
2.07 ± 0.4
0.91 ± 0.5
0.26 ± 0.08
0.3 ± 0.08
monophosphate
(ring)
treprostinil
0
0.76 ± 0.2
0.91 ± 0.7
1.52 ± 0.6
1.53 ± 0.6
1.65 ± 0.7
0.66 ± 0.1
0.15 ± 0.03
0.05 ± 0.02
monovaline (ring)
treprostinil
0
2.42 ± 0.6
2.52 ± 0.4
2.91 ± 0.6
3.25 ± 1.5
1.69 ± 0.4
0.55 ± 0.2
0.20 ± 0.1
0.22 ± 0.2
monoalanine
(ring)
treprostinil
0
9.53 ± 2.6
3.92 ± 0.6
3.83 ± 0.7
2.74 ± 0.9
0.86 ± 0.4
0.29 ± 0.2
0.08 ± 0.04
0.19 ± 0.3
monoalanine
(chain)
FIGS. 8-12 contain graphical representations of the plasma concentration versus time curves for Treprostinil in rat following administration of each prodrug. Table 13 lists each figure and the information displayed.
TABLE 13 FIG. Description 8 Intraduodenal dose of treprostinil monophosphate (ring) 9 Intraduodenal dose of treprostinil monovaline (ring) 10 Intraduodenal dose of treprostinil monoalanine (ring) 11 Intraduodenal dose of treprostinil monoalanine (chain) 12 Intraduodenal dose of each prodrug compared to treprostinil alone from Example 1
Pharmacokinetic Analysis
Bioavailability of the prodrug was determined relative to that of the active compound based on a previous study in which Treprostinil was dosed to rats. The following formula was used to determine relative bioavailability (F):
Relative F =( AUC (ProdrugDose) /Dose)/( AUC (Treprostinil Dose /Dose)*100
Absolute bioavailability was also estimated using data from an intravenous dose of Treprostinil in rats determined in Example 1. Results are listed in Table 14.
TABLE 14
List of Figures
FIG.
Description
8
Intraduodenal Dose of treprostinil monophosphate (ring)
9
Intraduodenal Dose of treprostinil monovaline (ring)
10
Intraduodenal Dose of treprostinil monoalanine (ring)
11
Intraduodenal Dose of treprostinil monoalanine (chain)
12
Intraduodenal Dose of Each Prodrug Compared to
Treprostinil Alone from Example 1
Conclusions
The relative intraduodenal bioavailabilities of four prodrugs of Treprostinil were determined in rats. All the compounds had relative intraduodenal bioavailabilities less than that of the active compound. treprostinil monophosphate (ring) and treprostinil monoalanine (ring) had the highest relative intraduodenal bioavailability at 56% and 38% respectively. The T max for treprostinil monophosphate (ring) and treprostinil monoalanine (chain) occurred 5 minutes post-dosing. treprostinil monovaline (ring) and treprostinil monoalanine (ring) had longer absorption times with T max values of 120 and 60 minutes respectively. Maximum Treprostinil concentrations were highest following treprostinil monophosphate (ring) and treprostinil monoalanine (chain) dosing. They reached approximately 9 ng/mL 5 minutes post-dosing. The bioavailabilities are much greater when dosed intraduodenally than when dosed orally as measured by treprostinil plasma levels.
References
1. WinNonlin User's Guide, version 3.1, 1998-1999, Pharsight Co., Mountain View, Calif. 94040.
Example 4
In this Example, Treprostinil concentrations will be determined in male Sprague-Dawley rats following a single oral or intraduodenal dose of the following compounds of structure II:
having the following substituents:
Cpd.
R 1
R 2
R 3
A
—CH 2 CONH 2
H
H
B
—CH 2 CON(CH 2 ) 2 OH
H
H
C
—CH 2 CON(CH 3 ) 2
H
H
D
—CH 2 CONHOH
H
H
E
—CH 2 C 6 H 4 NO 2 (p)*
H
H
F
—CH 2 C 6 H 4 OCH 3 (p)*
H
H
G
—CH 2 C 6 H 4 Cl (o)*
H
H
H
—CH 2 C 6 H 4 (NO 2 ) 2 (o, p)*
H
H
I
—CH 2 C 6 H 4 F (p)*
H
H
J
H
—PO 3 H 3
H
K
H
H
—PO 3 H 3
L
H
—COCH 2 NH 2
H
M
H
H
—COCH 2 NH 2
N
H
—COCH(CH 3 )NH 2
H
O
H
H
—COCH(CH 3 )NH 2
P
H
—COCH(CH 3 )NH 2
—COCH(CH 3 )NH 2
*o denotes ortho substitution, m denotes meta substitution and p denotes para substitution.
Examples of these compounds include:
Prodrug preparation and analysis will take place as described in Examples 1 and 2 above. Additionally, the oral bioavailability of treprostinil, treprostinil sodium and the compounds shown in Example 2 and this Example will be administered in close proximity to or simultaneously with various different p-glycoprotein inhibiting compounds at varying concentrations and tested to determine the effect of the p-glycoprotein inhibitors on the oral bioavailability of the compounds. The p-glycoprotein inhibitors will be administered both intravenously and orally.
Example 5
Clinical Studies with Treprostinil Diethanolamine
Introduction
Prior to proceeding directly into clinical studies with a sustained release (SR) solid dosage form of UT-15C (treprostinil diethanolamine), a determination of the pharmacokinetics of an oral “immediate release” solution was performed. The first clinical study (01-101) evaluated the ability of escalating doses of an oral solution of UT-15C to reach detectable levels in plasma, potential dose-plasma concentration relationship, bioavailability and the overall safety of UT-15C. Volunteers were dosed with the solutions in a manner that simulated a sustained release formulation releasing drug over approximately 8 hours.
The second clinical study (01-102) assessed the ability of two SR solid dosage form prototypes (i.e., 1. microparticulate beads in a capsule and, 2. tablet) to reach detectable levels in plasma and the potential influence of food on these plasma drug concentrations. The SR prototypes were designed to release UT-15C over approximately an 8 hour time period.
Details of the two clinical studies are described below.
Clinical Study 01-101
A Safety, Tolerability, and Pharmacokinetic Study of Multiple Escalating Doses of UT-15C (Treprostinil Diethanolamine) Administered as an Oral Solution in Healthy Adult Volunteers (Including Study of Bioavailability).
The oral solution of UT-15C was administered to 24 healthy volunteers to assess the safety and pharmacokinetic profile of UT-15C as well as its bioavailability. To mimic a SR release profile, doses were administered every two hours for four doses at either 0.05 mg per dose (total=0.2 mg), 0.125 mg per dose (total=0.5 mg), 0.25 mg per dose (total=1.0 mg), or 0.5 mg per dose (total=2.0 mg). Study endpoints included standard safety assessments (adverse events, vital signs, laboratory parameters, physical examinations, and electrocardiograms) as well as pharmacokinetic parameters.
All subjects received all four scheduled doses and completed the study in its entirety. Treprostinil plasma concentrations were detectable in all subjects following administration of an oral solution dose of UT-15C. Both AUC inf and C max increased in a linear fashion with dose for each of the four dose aliquots. The highest concentration observed in this study was 5.51 ng/mL after the third 0.25 mg solution dose aliquot of the 2.0 mg UT-15C total dose. Based on historical intravenous treprostinil sodium data, the mean absolute bioavailability values for the 0.2 mg, 0.5 mg, 1.0 mg and 2.0 mg doses of UT-15C were estimated to be 21%, 23%, 24% and 25%, respectively. The results of this study are respectively shown in FIGS. 13A-13D .
UT-15C was well tolerated by the majority of subjects at all doses given. There were no clinically significant, treatment emergent changes in hematology, clinical chemistry, urinalysis, vital signs, physical exams, and ECGs. The most frequently reported adverse events were flushing, headache, and dizziness. This safety profile with UT-15C (treprostinil diethanolamine) is consistent with the reported safety profile and product labeling of Remodulin (treprostinil sodium) and other prostacyclin analogs. Thus, changing the salt form of treprostinil did not result in any unexpected safety issues following the protocol specified dosing regimen (i.e. single dose every 2 hours for four total doses on a single day).
Clinical Study 01-102
A Safety, Tolerability, and Pharmacokinetic Study Comparing a Single Dose of a Sustained Release Capsule and Tablet Formulation of UT-15C (Treprostinil Diethanolamine) Administered to Healthy Adult Volunteers in the Fasted and Fed State
The 01-102 study was designed to evaluate and compare the safety and pharmacokinetic profiles of a (1) UT-15C SR tablet prototype and, (2) UT-15C SR capsule prototype (microparticulate beads in a capsule) in both the fasted and fed state. Each of the SR dosage forms weres designed to release UT-15C (1 mg) over an approximate 8-hour time period. Fourteen healthy adult volunteers were assigned to receive the SR tablet formulation while an additional fourteen volunteers were assigned to receive the SR capsule formulation. Subjects were randomized to receive a single dose (1 mg) of their assigned SR prototype in both the fasted and fed state. A crossover design was employed with a seven day wash-out period separating the fed/fasted states. For the fed portion of the study, subjects received a high calorie, high fat meal. Study endpoints included standard safety assessments (adverse events, vital signs, laboratory parameters, physical examinations, and electrocardiograms) as well as pharmacokinetic parameters.
All subjects administered UT-15C SR tablets and capsules had detectable treprostinil plasma concentrations. Calculations of area under the curve from zero to twenty-four hours (AUC 0-24 ) indicate that total exposure to UT-15C SR occurred in the following order: Tablet Fed>Capsule Fasted>Tablet Fasted>Capsule Fed. FIG. 14 displays the pharmacokinetic profiles of the two formulations in the fasted and fed states.
UT-15C SR tablets and capsules were tolerated by the majority of subjects. All adverse events were mild to moderate in severity and were similar to those described in Study 01-101 and in Remodulin's product labeling. Additionally, there were no treatment-emergent changes in vital signs, laboratory parameters, physical examinations, or electrocardiograms throughout the study.
These results demonstrate that detectable and potentially therapeutic drug concentrations can be obtained from a solid dosage form of UT-15C and that these concentrations can be maintained over an extended period of time through sustained release formulation technology.
Polymorphs of Treprostinil Diethanolamine
Two crystalline forms of UT-15C were identified as well as an amorphous form. The first, which is metastable, is termed Form A. The second, which is thermodynamically more stable, is Form B. Each form was characterized and interconversion studies were conducted to demonstrate which form was thermodynamically stable. Form A is made according to the methods in Table 15. Form B is made from Form A, in accordance with the procedures of Table 16.
TABLE 15
XRPD
Sample
Solvent
Conditions a
Habit/Description
Result b
ID
tetrahy-
FE
opaque white solids;
A
1440-
drofuran
morphology unknown,
72-02
birefringent
SE
glassy transparent
A (PO)
1440-
solids
72-03
SC (60° C.)
translucent, color-
A
1440-
less glassy sheets
72-16
of material, bi-
refringent
Toluene
slurry (RT),
white solids;
A + B
1440-
6 d
opaque masses of
72-01
smaller particles
toluene:
SC(60° C.)
white solids; spherical
A
1480-
IPA
clusters of fibers,
21-03
(11.4:1)
birefringent
Water
FE
opaque white solids;
A
1440-
morphology unknowm,
72-07
birefringent
SE
opaque ring of solids,
A + B
1440-
birefringent
72-08
freeze dry
white, glassy trans-
A + B
1480-
parent solids
58-02
water:
FE
opaque white solids;
A +
1440-
ethanol
morphology unknown,
11.5 pk
72-09
(1:1)
birefringent
FE
clear and oily sub-
B
1480-
stance with some
79-02
opaque solids
SE
glassy opaque ring
A
1440-
of solid
72-10
a FE = fast evaporation; SE = slow evaporation; SC = slow cool
b IS = insufficient sample; PO = preferred orientation; LC = low crystallinity; pk = peak
c. XRPD = X-ray powder diffraction
TABLE 16 XRPD Solvent Conditions Habit/Description Result Sample ID ethanol/ FE glassy appearing — b 1519- water solids of unknown 68-01 (1:1) morphology; bi- refringent 1,4-di- slurry(50° C.), white solids; B 1519- oxane 6 d opaque masses of 73-02 a material; mor- phology unknown slurry(50° C.), small grainy B 1557- 2 d solids; with 12-01 birefringence subsample of — B 1557- 1557-12-01 15-01 subsample of white solids B 1557- 1557-12-01 15-02 slurry(50° C.), — B 1557- 2 d 17-01 isopro- slurry(RT), 1 d white solids — b 1519- panol 96-03 tetrahy- slurry(RT), 1 d — — b 1519- drofuran 96-02 toluene slurry(50° C.), white solids B 1519- 6 d 73-01 a Seeds of sample # 1480-58-01 (A + B) added b Samples not analyzed
Characterization of Crystal Forms:
Form A
The initial material synthesized (termed Form A) was characterized using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetry (TG), hot stage microscopy, infrared (IR) and Raman spectroscopy, and moisture sorption. Representative XRPD of Form A is shown in FIG. 15 . The IR and Raman spectra for Form A are shown in FIGS. 16 and 17 , respectively. The thermal data for Form A are shown in FIG. 18 . The DSC thermogram shows an endotherm at 103° C. that is consistent with melting (from hot stage microscopy). The sample was observed to recrystallize to needles on cooling from the melt. The TG data shows no measurable weight loss up to 100° C., indicating that the material is not solvated. The moisture sorption data are shown graphically in FIG. 19 . Form A material shows significant weight gain (>33%) during the course of the experiment (beginning between 65 to 75% RH), indicating that the material is hygroscopic. In addition, hygroscopicity of treprostinil diethanolamine was evaluated in humidity chambers at approximately 52% RH and 68% RH. The materials were observed to gain 4.9% and 28% weight after 23 days in the ˜52% RH and ˜68% RH chambers, respectively.
Based on the above characterization data, Form A is a crystalline, anhydrous material which is hygroscopic and melts at 103° C.
Form B
Treprostinil diethanolamine Form B was made from heated slurries (50° C.) of Form A in 1,4 dioxane and toluene, as shown in Table 16. Material isolated from 1,4-dioxane was used to fully characterize Form B. A representative XRPD pattern of Form B is shown in FIG. 20 . Form A and Form B XRPD patterns are similar, however, significant differences are observed in the range of approximately 12-17° θ ( FIG. 20 ).
The thermal data for Form B are shown in FIG. 21 . The DSC thermogram (Sample ID 1557-17-01) shows a single endotherm at 107° C. that is consistent with a melting event (as determined by hotstage microscopy). The TG shows minimal weight loss up to 100° C.
The moisture sorption/desorption data for Form B are shown in FIG. 22 . There is minimal weight loss at 5% RH and the material absorbs approximately 49% water at 95% RH. Upon desorption from 95% down to 5% RH, the sample loses approximately 47%.
Form A and Form B can easily be detected in the DSC curve. Based on the above characterization data, Form B appears to be a crystalline material which melts at 107° C.
Thermodynamic Properties:
Inter-conversion experiments were carried out in order to determine the thermodynamically most stable form at various temperatures. These studies were performed in two different solvents, using Forms A and B material, and the data are summarized in Table 17. Experiments in isopropanol exhibit full conversion to Form B at ambient, 15° C., and 30° C. after 7 days, 11 days, and 1 day, respectively. Experiments in tetrahydrofuran also exhibit conversion to Form B at ambient, 15° C., and 30° C. conditions. Full conversion was obtained after 11 days at 15° C., and 1 day at 30° C. At ambient conditions, however, a minor amount of Form A remained after 7 days based on XRPD data obtained. Full conversion would likely occur upon extended slurry time. Based on these slurry inter-conversion experiments, Form B appears to be the most thermodynamically stable form. Form A and Form B appear to be related monotropically with Form B being more thermodynamically stable.
TABLE 17
Interconversion Studies of Treprostinil Diethanolamine
Experiment/
Sample
Starting
No.
Forms
Solvent
Materials
Temperature
Time
1557-
A vs. B
isopro-
solid mixture
ambient
7
days
22-01
panol
# 1557-20-01 a
1557-
A vs. B
solid mixture
15° C.
11
days
47-02
# 1557-35-01 d
1557-
A vs. B
solid mixture
30° C.
1
day
33-02
# 1557-35-01 d
1557-
A vs. B
solid mixture
50° C.
—
21-02 e
# 1557-20-01 b
1557-
A vs. B
tetrahy-
solid mixture
ambient
7
days
20-03
drofuran
# 1557-20-01 c
1557-
A vs. B
solid mixture
15° C.
11
days
47-01
# 1557-35-01 d
1557-
A vs. B
solid mixture
30° C.
1
day
33-01
# 1557-35-01 d
1557-
A vs. B
solid mixture
50° C.
—
21-01 e
# 1557-20-01 c
a saturated solution Sample ID 1557-21-03
b saturated solution Sample ID 1519-96-03
c saturated solution Sample ID 1519-96-02
d saturated solution prepared just prior to addition of solids
e samples not analyzed as solubility (at 50° C.) of treprostinil diethanolamine was very high and solutions became discolored.
All references disclosed herein are specifically incorporated by reference thereto.
While preferred embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the invention in its broader aspects as defined herein.
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This invention pertains generally to prostacyclin analogs and methods for their use in promoting vasodilation, inhibiting platelet aggregation and thrombus formation, stimulating thrombolysis, inhibiting cell proliferation (including vascular remodeling), providing cytoprotection, preventing atherogenesis and inducing angiogenesis. Generally, the compounds and methods of the present invention increase the oral bioavailability and circulating concentrations of treprostinil when administered orally. Compounds of the present invention have the following formula:
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FIELD OF THE INVENTION
[0001] The present invention relates to a process for thickening foodstuffs, in particular thickening liquid, pourable or squeezable or spoonable foodstuffs, as well as to a thickening agent and the preparation thereof.
BACKGROUND OF THE INVENTION
[0002] A broad range of thickeners is conventionally employed to achieve the desired thickness and consistency of various (liquid, pourable or squeezable) foodstuffs. Well-known in this respect are the use of starch and gellable biopolymers or gums. Examples of the latter group are gelatin, agar, carrageenans, pectins, alginates, xanthan, locust bean gum etcetera.
[0003] The application of (native) starch, however, may result in a sticky mouthfeel and/or characteristic smell or flavour of starch, which is less desirable. Also, the use of starch as a thickener may result in less heat stability of the thickened foodstuff and/or retrogradation upon cooling.
[0004] The use of native starch as a thickener without gums will generally result in a gelled consistency when cooling as a result of a network formed by the amylose when leached out from the starch granules during processing, which is undesirable for preparing pourable foodstuffs such as e.g. sauces.
[0005] The disadvantage of reduced heat stability and/or retrogradation may be overcome by the application of (chemically) modified starches, which are in many countries to be labeled as such on the packaging of the foodstuff concerned, and are as such less attractive.
[0006] The use of native starch mixed in combination with certain gums may overcome some of the disadvantages of using native starch alone: applying heat will result in amylose leaching out of the starch granules, but phase separation occurs due to the presence of the gums.
[0007] The application of gums has its disadvantages as well, ranging from a tendency to produce slimy or slightly gellified foodstuffs to non-vegetable origin (e.g. gelatin) to high costs (most gums). Additional disadvantages include reduced heat-stability for many gums similar to that of starch.
[0008] Various solutions have been proposed in the past in order to overcome the disadvantages mentioned above. A solution w.r.t. the heat stability has been proposed in WO 95/12323. Herein it is disclosed that such problems may be overcome by application of a non-pre-gelatinised starch that is present in the foodstuff as a dispersed phase in a gum.
[0009] Another attempt to overcome some of the problems as set out above is presented in JP 57/202257 (Yakult Honsha KK). Herein it is disclosed that soups, curry's, stews, sauces and the like may be thickened by the incorporation of smashed, steamed and homogenised vegetables which are rich in starch. Rich in starch is reported in this reference to mean vegetable containing about 70% or more starch in the dry vegetable, such as potato, sweet potato, taro, cassava, and pumpkin. The homogenisation is according to this reference to be carried out at pressures between 30-150 bar, with 50-80 bar being preferred. The pressures actually used are 75 and 80 bar.
SUMMARY OF THE INVENTION
[0010] Although the solutions given above may be sufficient for some applications, it has been found that for others these are not sufficient. For example, the solutions as proposed by JP 57/202257 still give rise to undesired starchy flavours. Additionally, the homogenised vegetables as disclosed in that reference lead to the formation of gelled compositions upon cooling, unless gums such as gelatins (e.g. in the form of bouillons) are also included in the application.
[0011] Hence, there was a need for a process for thickening liquid, pourable or squeezable foodproducts without the disadvantages as mentioned above, preferably independent upon temperature during manufacture or use. In other words, the so obtained thickened food products should be thickened but preferably not gelled, be free of a starchy flavor or smell, be at least reasonably stable under heating and cooling conditions, and preferably provide a thickening effect both in hot (e.g. sauces, soups) or cold (e.g. sauces, dressings, mayonnaise) applications.
[0012] Furthermore, the thickened foodstuff should preferably be free of gums from non-vegetable origin (such as gelatin). Preferably, the foodstuff so prepared should also be free of other gums or thicking biopolymers. Additionally, the thickened foodstuff should be free of any grainy or sandy texture resulting from the thickener.
[0013] It has now been found that the above can be achieved by a process for thickening a liquid, pourable or squeezable foodproduct by adding to said foodproduct a vegetable homogenate obtained by subjecting a comminuted vegetable to a homogenisation treatment, wherein the vegetable contains less then 70% starch, based on dry matter. The thickening effect can be obtained both in hot and cold preparations, and compositions can be reheated without substantial change in thickening effect.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The prior art in JP 57/202257 seems to rely on a thickening effect by liberating starch that is available in starch-rich vegetables as are exemplified therein. This still does not solve a number of the problems as set out above. For example a gum (e.g. gelatin, either added as such or in the form of a bouillon) will still be needed in order to avoid the formation of a gelled foodstuff upon cooling. This is due to the presence of starch, although now originating from starch-rich vegetables instead of a different source. The product prepared according to this reference will also result in some starchy flavour or smell being present. Also, retrogradation may occur.
[0015] In contrast to this, in the present invention the thickening effect is obtained also from homogenised vegetables, but now from vegetables which do not need to be high in starch content. In fact, the thickening effect is more or less independent upon the content of starch of the vegetable used, and in order to overcome some of the disadvantages related to the use of starch as a thickener (as set out above), the content of starch of the vegetable used is preferably low. For the person of average skill in the art, it is surprising that, when confronted with the disclosure as mentioned above, a thickening effect can achieved without much starch being present.
[0016] Without wishing to be bound by any theory, it is believed that in the present invention the tickening effect is obtained by the presence of a mixture of intact vegetable cells, cell debris, cell wall fragments, etcetera.
[0017] In the process according to this invention and as set out above it is preferred that the starch content of the vegetables used for preparing the homogenised vegetable puree is less than 50% based on the dry vegetable, more preferably even lower than 35%.
[0018] Preferred vegetables for this invention are (apart from the above mentioned requirements) vegetables of white or pale colour, e.g. parsnips, mushrooms, cauliflower, swede, and turnips. For specific foodstuffs vegetables having a green or orange color, like carrots, broccoli, may also be used. Needless to say, mixtures may also be used. Particularly preferred vegetables are plants of the genus Brassica oleracea and also roots or root-like vegetables, all preferably being low in starch.
[0019] Less suitable (following their high starch content) are the vegetables as mentioned in JP 57/202257: potato, sweet potato, taro, cassava and pumpkin. Also less suitable for the purpose of the invention are tomatoes.
[0020] In the process according to the present invention the homogenisation treatment can be effected by any homogeniser suitable for application to foodstuffs. As various types of homogenisers operate following different principles, homogenisation pressures from one type of homogeniser to another type of homogeniser cannot be compared directly. It was found in the present case that homogenisation of the vegetables is preferably carried out by a high pressure homogeniser at a pressure of 100-200 bar or any equivalent treatment (in terms of results) by a different type of homogeniser, such as an ultrasonic homogeniser. For some purposes, pressures higher than 150 bar may be preferred.
[0021] In the process according to the invention, it is preferred that prior to the homogenisation step the vegetables are cooked. Preferably, the homogenisation operation is also preceded by a comminuting (including chopping, slicing, etcetera) operation, leading e.g. to a puree. Depending e.g. on the vegetables chosen, they may be peeled and/or parts of the vegetable (e.g. leaf, stem, bruised spots) may be removed first.
[0022] It was found that the homogenised vegetable puree according to the invention shows very good (physical) stability, without substantial phase separation, thinning, syneresis over periods of up to 6 weeks or more.
[0023] It was also found that the homogenised vegetable compositions prepared according to the invention are free of sandy or grainy texture, and provide a smooth mouthfeel, both in pure form and upon usage in diluted form.
[0024] The homogenised vegetable prepared along the lines as set out above may be applied to a given foodstuff in any desired quantity, e.g. in an amount of 5 to 80% by weight, based on the final formulation. However, for obtaining the desired thickening effect for liquid, pourable or squeezable foodstuffs it may be preferred to incorporate the homogenised vegetable puree in the foodstuff in an amount of between 10 and 60%, more preferably 20-45% by weight based on the final food product. The amount also depends on the vegetable used and the desired thickness. The right amount needed can readily be determined by the person of average skill in the art.
[0025] The material according to the invention can most suitable be added to foodstuffs which need to be liquid, pourable, squeezable or spoonable, such as soups, sauces, simmer sauces, sauce base products, dressings, mayonnaise, etcetera.
[0026] The homogenised vegetable puree is suitable for application to aqueous foodstuffs, in particular suitable for thickening sauces, simmer sauces, sauce base products (which are to be diluted by an aqueous liquid prior to consumption) and the like. Also, the homogenised vegetable puree can be incorporated into emulsified foodstuffs, like mayonnaise, dressings or fat/oil-containing sauces. The thickened foodstuffs according to the invention can be consumed both cold and hot, without substantial change in thickness.
[0027] Depending upon the intended use of the thickened foodstuff it may further contain water, organic acids, oil, fat, herbs, spices, comminuted vegetables, or mixtures thereof.
[0028] In the present invention, the use of thickeners based on non-starch like biopolymers like gelatin, agar, alginate, carrageenans, xanthan, pectins and pect(in)ic substances, CMC and the like can be dispensed with. Hence, a foodstuff thickened according to this invention preferably does not contain substantial amounts of thickeners or gellable compounds from animal origin (e.g. gelatin).
[0029] The present invention further relates to a liquid, pourable or squeezable foodproduct containing 5-80% by weight (preferably 10-60%) of a vegetable puree, wherein the vegetable puree has been homogenised, and wherein the starch content of the vegetable is less than 70%, based on the or vegetable. It is preferred that the vegetable in the above has been homogenised by a high-pressure homogeniser at a pressure of 100-200 bar, or any equivalent (in terms of results obtained) homogenising treatment.
[0030] The invention further relates to the use of vegetable puree, wherein the vegetable puree has been homogenised, and wherein the starch content of the vegetable is less than 70%, based on the dry vegetable for thickening liquid, pourable or squeezable foodstuffs. It is preferred that the vegetable in the above has been homogenised by a high-pressure homogeniser at a pressure of 100-200 bar, or any equivalent (in terms of results obtained) homogenising treatment.
[0031] The invention is further exemplified by the following examples, which are to be understood as to be non-limiting.
[0032] EXAMPLES
Examples 1-7
[0033] Seven sauces have been prepared with different homogenised vegetables as thickener, homogenisation pressures of the vegetables, and amounts of homogenised vegetable, as set out in table 1.
[0034] For the eight examples various sauces were prepared, in which was present (percentage by weight):
sunflower oil 10 % modified egg-yolk 0.5% salt 0.4% sugar 0.6% homogenised vegetable see table 1 for amount water to the balance
[0035] [0035] TABLE 1 vegetable type, amount and homogenisation pressures amount of homogenised Homogenisation Example Vegetable used vegetable (wt %) pressure (bar) 1 Parsnips 45% 150 2 Parsnips 45% 200 3 Parsnips 45% 100 4 Parsnips 60% 150 5 Parsnips 45% 150 6 Carrots 75% 150 7 Broccoli 45% 150
Processing Examples 1-4
[0036] The vegetables were peeled, sliced and cooked in deionized boiling water for 15 minutes. Thereafter, they were pureed in an industrial food processor (Robocoup Juicer) with a 0.5 mm sieve.
[0037] The so-obtained vegetable purees were added to a pre-emulsion, which was prepared by mixing water, modified egg yolk, and oil in the amounts given above, after which salt and sugar were added.
[0038] The so-prepared mixture was passed through a high-pressure homogeniser (type Niro Soavi Pand lab Bench Model, at pressures indicated in table 1) to obtain the sauce (appearance: smooth and creamy)
[0039] The cold, emulsified sauce was heated to boiling, hot filled in glass jars and pasteurised.
[0040] The pasteurised samples were stored for 6 weeks (chilled), opened and reheated, which resulted in a smooth, thick, sauce having good mouthfeel and appearance.
Processing Example 5
[0041] Example 1 (45% parsnips, homogenised at 150 bar) was repeated, apart from that the pureed vegetable (and part of the water) and the rest of the sauce ingredients were passed through the high-pressure homogeniser (type Niro Soavi Pand lab Bench Model, at 150 bar) separately, and then mixed. In order to homogenise the vegetable puree, part of the water (30%) was added to the vegetable puree to be homogenised. The rest of the processing was the same. The resulting product was not distinguishable from the product from example 1.
Processing Example 6
[0042] Identical to example 1, apart from that carrots were used, in an amount of 75% (wt), and the amount of added water was less as a consequence of the increased amount of vegetable matter.
[0043] The appearance was the same as for example 1, apart from the color (being yellowish/orange for the carrots). A slight carrot taste could be detected.
Processing Example 7
[0044] Broccoli florets were cut into pieces, 2-3 cm in length and the majority of the stalk discarded. They were then treated as the parsnips in example 5. The resulting product had an appearance as the product in example 1, apart from the color (green). Mouthfeel was very much similar.
Example 8
[0045] In this example homogenised carrots have been used to thicken a tomato sauce.
[0046] Carrots were peeled, sliced and cooked in deionized boiling water for 15 minutes. The vegetables were pureed using an industrial food processor (Robocoup Juicer) with a 0.5 mm sieve. The so-obtained vegetable puree was mixed with 30% of water and passed through a high pressure homogeniser (type Niro Soavi Pand Lab Bench Model, at a pressure of 150 bar) to obtain the carrot homogenate.
[0047] Remainder of the water (see table below), tomato paste (Brix 28), oil and salt were mixed together.
[0048] The carrot homogenate was added to the tomato sauce to obtain a thick, smooth tomato sauce having the following final composition:
Ingredients % Homogenised carrot 20 tomato paste 7.3 Soybean oil 1.6 Salt 0.8 Water 70.3 100
[0049] The cold sauce was heated to boiling, hot filled in glass jars and pasteurised.
[0050] The pasteurised samples were stored for 6 weeks (chilled), opened and reheated, which resulted in a smooth, thick, tomato sauce having good mouthfeel and appearance.
Example 9
[0051] A basic sauce was prepared from homogenised parsnip-puree.
[0052] The parsnips were peeled, sliced and cooked in deionized boiling water for 15 minutes. Thereafter, they were pureed in an industrial food processor (Robocoup Juicer) with a 0.5 mm sieve.
[0053] The so-obtained parsnip puree was mixed with 30% of water and passed through a high-pressure homogeniser (type Niro Soavi Pand lab Bench Model, at 150 bar) to obtain a basic sauce (appearance: smooth, thick and non-gritty). After chilled storage for 6 weeks the physical appearance (thick, smooth, non-gritty) was not changed.
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There was a need for a process for thickening liquid, pourable or squeezable foodproducts without the disadvantages as mentioned above, preferably independent upon temperature during manufacture or use. In other words, the so obtained thickened food products should be thickened but preferably not gelled, be free of a starchy flavor or smell, be at least reasonably stable under heating and cooling conditions, and preferably provide a thickening effect both in hot (e.g. sauces, soups) or cold (e.g. sauces, dressings, mayonnaise) applications.
Furthermore, the thickened foodstuff should preferably be free of gums from non-vegetable origin (such as gelatin). Preferably, the foodstuff so prepared should also be free of other gums or thicking biopolymers. Additionally, the thickened foodstuff should be free of any grainy or sandy texture resulting from the thickener.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a Continuation of U.S. patent application Ser. No. 09/874,136, filed Jun. 5, 2001, now U.S. Pat. No. 6,350,287 B1, which is a Divisional of U.S. patent application Ser. No. 09/621,896, filed Jul. 20, 2000, now U.S. Pat. No. 6,273,919, which claims priority benefit of U.S. Provisional Patent Application No. 60/211,301, filed Jun. 13, 2000, the disclosures of which are incorporated herein by reference. In addition, U.S. patent application Ser. No. 09/621,896 is a Continuation-in-Part of U.S. patent application Ser. No. 09/402,412, filed Jan. 12, 2000, now U.S. Pat. No. 6,156,074, which application, in turn, is a §371 of PCT/US98/06811, filed Apr. 6, 1998, which, in turn, is a Continuation-in-Part of U.S. patent application Ser. No. 08/833,341, filed Apr. 4, 1997, now U.S. Pat. No. 5,888,250, the disclosures of all of which are also incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a novel glycol ether dry-cleaning solvent and a method for effecting dry-cleaning using said solvent. More particularly, the present invention relates to a glycol ether solvent that not only is comparable or superior to perchloroethylene in its attributes and benefits, and does not suffer from the serious environmental, health and occupational negatives and problems associated with the use of perchloroethylene, but which also represents an improvement over the current glycol ether solvents that are contemplated as replacements for perchloroethylene.
Perchloroethylene is the most widely used dry-cleaning solvent, and is commonly referred to (and will be referred to sometimes hereinafter) as “perc”. Perc is a chlorinated hydrocarbon-based solvent. It is the dry-cleaning solvent of choice throughout North America, Europe and Asia.
In addition to perc's use in the dry-cleaning industry, it has found extensive use as a degreasing agent in the metals industry, in the scouring/milling of wool, and in various “clean room” applications in the semiconductor and electronics industries. The industrial uses of perc are approximately ten-fold greater than its use as a solvent for dry cleaning.
While perc has been found to be an effective dry-cleaning agent because it is non-flammable, does not damage synthetic fabrics or cause shrinkage to fabrics containing naturally occurring fibers, such as wool, and has a relatively low boiling point that permits its being reclaimed and purified by means of ordinary distillation, it does present a number of other problems which present drawbacks to its use. In particular, perchloroethylene presents a number of health and environmental hazards that would militate against its continued use, provided a substitute solvent of comparable quality were available that was free of the aforementioned hazards.
Because perc is heavier than water, its disposal represents a significant environmental risk because it will sink to the bottom of an aquifer, lake, river, and the like, with possibly resultant contamination of the water supply. Additionally, perc vapors have been implicated as having a deleterious effect on the central nervous system. In addition, because it is a highly chlorinated molecule, perc has been identified as being a significant health hazard to cattle, and as a cause of skin cancer, particularly melanoma, because of the action of the chlorine in perc depleting oxygen from the ozone layer. Furthermore, and of particular import, is the fact that perc is not biodegradable and, hence, will over a period of time accumulate, presenting a significant industrial waste disposal hazard.
As the nature and seriousness of the foregoing problems become more and more manifest with the passage of time and with the completion of various research and clinical investigations into the nature of perc and its mechanisms of action, the use of alternative solvents has been sought, but none have met with any degree of commercial success since they could not match the result obtained by perc as a dry-cleaning agent.
However, at this point in time, when environmental concerns are being rigorously monitored and policed by domestic and foreign governments by means of legislation and civil and even criminal prosecution, the need for a substitute solvent for perc for dry-cleaning operations, as well as other operations, has become a matter of some degree of urgency.
A difficulty in identifying a replacement dry-cleaning solvent for perc is that it must meet so many requirements, both as to its efficacy as a dry-cleaning agent, i.e. high purity, non-shrinking with respect to about 160 types of fabric, dye-fast for non-bleeding with respect to about 900 types of dyes, a high flashpoint to render it non-flammable and non-combustible, the ability to separate from water, effective detergency, ease of distillation, simplicity of reclamation, compatibility with existing dry-cleaning equipment, and the like, as well as its being non-polluting to the water supply and the ozone layer, biodegradable, non-toxic, non-carcinogenic, and the like.
One proposed solvent substitute, namely propylene glycol monomethyl ether, which is disclosed in EP 479,146 as possessing many desirable properties, was found to be wanting in that it causes damage to weak dyes, fine yarns, and delicate fabrics, such as acetates, because of its pronounced tendency to accumulate water from the environment, and from fabrics being dry-cleaned. Water accumulation or water-miscibility is also a decided negative from another aspect in that it significantly impairs the efficiency of the dry-cleaning process because the dry-cleaning equipment is burdened with the handling of excessive quantities of water and the solvent stock is diluted and must be brought back to a correct ratio for stability reasons.
Propylene glycol tertiary-butyl ether (PTB) and propylene glycol n-butyl ether (PNB) were disclosed by WO 98/45523 as being superior alternatives to propylene glycol monomethyl ether. PTB and PNB were disclosed to possess all of the dry-cleaning attributes associated with perc and none of its drawbacks. The water-absorbing capabilities of both solvents was disclosed to be within a range effective in preventing damage to acetates and the tendency of woolen garments to shrink in water. The water absorption also lowered the solvent boiling point while raising the flashpoint. Both solvents were also disclosed to be non-pollutants of the water supply and ozone layer, biodegradable, non-toxic and non-carcinogenic. In addition, both solvents were capable of being used in existing perc dry-cleaning equipment.
Aqueous PTB and PNB dry-cleaning compositions have flashpoints within industry standards. However, there has recently been a regulatory trend toward a higher flashpoint standard. Furthermore, regulatory agencies are also considering making the standard applicable to individual components of a composition, even if the flashpoint of the overall composition meets industry standards. Accordingly, there exists a need for dry-cleaning compositions based on higher flashpoint glycol ethers.
The conventional wisdom has been, however, that higher flashpoint glycol ethers make poor dry cleaning solvents because they are too incompatible with water. While glycol ether dry-cleaning solutions containing too much water are undesirable because of the consequential shrinkage to woolens and damage to acetates, not to mention the solvent dilution, a low water content hampers the ability of the dry cleaning composition to remove water-soluble stains, which make up the bulk of stains to be removed from garments requiring dry cleaning. Thus, the need for dry-cleaning compositions based on higher flashpoint glycol ethers remains unsatisfied.
SUMMARY OF THE INVENTION
This need is met by the present invention.
In line with the foregoing, it is an object of the present invention to provide a solvent which possesses comparable, if not superior chemical and physical properties when compared to perc in dry cleaning, the cleaning of scoured and mill wool, and the dying of fabrics, while, simultaneously, protecting the environment, public health and safety from the many known negatives associated with the use of perc.
It is a further object of the present invention to provide a solvent which possesses comparable, if not superior chemical and physical properties when compared to lower flashpoint glycol ethers when used in such end-use applications.
It is a further object of the present invention to provide a dry-cleaning solvent that has a specific gravity less than that of water.
It is still a further object of the present invention to provide a dry-cleaning solvent that minimizes or eliminates the shrinkage of woolen garments, prevents or limits the bleeding of dyes, and which is able to treat acetates, silks, virgin wool and other delicate fabrics gently so as to avoid damage.
It is still another object of the present invention to provide a solvent for dry-cleaning, fabric dying and the cleaning of scoured and milled wool, the individual components of which have flashpoints within industry standards, yet at the same time has a sufficiently low boiling point to allow the solvent to be reclaimed and purified via conventional distillation processes.
It is still yet another object of the present invention to provide a dye solution containing dyes that are not water-soluble and a solvent that minimizes or eliminates the shrinkage of woolen fabrics and does not damage acetates, silks, virgin wools and other delicate fabrics, yet penetrate the fabric fiber sufficiently to form a strong dye bond to fabric fibers.
It has now been discovered that dipropylene glycol tertiary butyl ether (DPTB) has a flashpoint far above current industry standards, yet at the same time possesses a degree of solvency for water-soluble stains that is at least equivalent to, and in most cases better than, perc and the other glycol ether dry cleaning solvents presently in commercial use. Furthermore, this degree of solvency increases as water is added to DPTB up to the maximum quantity soluble in the solvent at room temperature, typically about 10% by weight of the total composition.
Therefore, according to one embodiment of the present invention, a dry-cleaning composition is provided containing dipropylene glycol tertiary-butyl ether (DPTB), water and a fabric softening agent in an amount effective to soften the fabric of garments cleaned with the dry-cleaning composition, wherein the weight ratio of DPTB to water is at least about 9:1.
DPTB absorbs water under ambient conditions to the point of saturation, some of which is bound as an azeotrope. Therefore, commercial grades of DPTB unavoidably contain some water. Preferred dry cleaning compositions according to the present invention contain about 90% by weight of DPTB and about 10% by weight of water.
The ability of DPTB to absorb water increases as the temperature of the composition increases, so that even compositions that are moisture saturated at room temperature will absorb water from garments when heated during the dry cleaning process. The dry cleaning compositions of the present invention will thus absorb water from the garments being dry cleaned. The water is then separated from the solvent by azeotropic distillation, with the recovery of essentially pure DPTB with an azeotropic level of water.
Therefore, the present invention also includes a method for dry-cleaning garments using the dry-cleaning compositions of the present invention. Methods in accordance with this embodiment of the present invention treat the garments with a composition containing dipropylene glycol tertiary-butyl ether (DPTB) and water for a period of time sufficient to effect dry-cleaning, wherein the weight ratio of DPTB to water is at least about 9:1.
The compositions of the present invention can also be used to clean, scour and mill wool. Methods in accordance with this embodiment of the present invention treat the scoured and milled wool with a composition containing dipropylene glycol tertiary-butyl ether (DPTB) and water for a period of time sufficient to effect cleaning, wherein the weight ratio of DPTB to water is at least about 9:1.
The compositions of the present invention can also be used for wool scouring and milling processes as well. In accordance with this embodiment of the present invention, a method of scouring wool is provided characterized by scouring the wool with the compositions of the present invention containing dipropylene glycol tertiary-butyl ether (DPTB) and water, wherein the weight ratio of DPTB to water is at least about 9:1. The solvent compositions of the present invention cleanly dissolve the lanolin contained in the raw wool for subsequent recovery and purification for use as an ingredient in cosmetics and other products.
According to another embodiment of the present invention, a method is provided for milling wool, characterized by milling the wool with a composition containing dipropylene glycol tertiary-butyl ether (DPTB) and water, wherein the weight ratio of DPTB to water is at least about 9:1.
The present invention further incorporates the discovery that water-insoluble dyes that are soluble in aliphatic glycol ethers are soluble in the compositions of the present invention to provide compositions that may be used to dye non-woolen fabrics with significantly improved colorfastness. The drying times of fabrics dyed with the dye compositions of the present invention significantly decreased as well, yet at the same time, a stronger bond between the dye molecules and the fabric fibers is formed.
Therefore, according to another aspect of the present invention, a composition for dyeing fabrics is provided that is a solution of a water-insoluble aliphatic glycol ether-soluble dye dissolved in a solvent containing dipropylene glycol tertiary-butyl ether (DPTB) and water, wherein the weight ratio of DPTB to water is at least about 9:1.
According to another embodiment of the present invention, a method is provided for dyeing fabric with the dye compositions of the present invention. Methods in accordance with this aspect of the present invention treat the fabric for a period of time sufficient to effect dyeing with a dye composition containing a solution of a water-insoluble aliphatic glycol ether soluble dye dissolved in a solvent containing dipropylene glycol tertiary-butyl ether (DPTB) and water, wherein the weight ratio of DPTB to water is at least about 9:1. Methods in accordance with the present invention further include the step of drying the fabric after the step of treating the fabric to effect dyeing is completed.
The compositions of the present invention were discovered to present several unexpected properties in comparison to perc and commercial glycol ether compositions. Fabrics that were cleaned or dyed, and raw wool that was milled, scoured or cleaned, with the compositions of the present invention had virtually no residual odor, unlike raw wool and fabrics processed with perc or other commercial glycol ether compositions. What odor that was detectable was pleasant. In addition, the odor of DPTB could not be “reactivated” with water, meaning that virtually no residual solvent remained in the fabric. This is in contrast to garments cleaned with perc or other commercial glycol ethers, which produce a strong solvent odor if subsequently contacted with water.
In addition, fabric that was dry-cleaned or dyed with the compositions of the present invention dryed virtually wrinkle-free with a noticeably soft hand, particularly in comparison to fabrics that were similarly treated with perc, or other commercial glycol ether compositions. Thus, fabrics cleaned or dyed with the compositions of the present invention require significantly less ironing or other processing to remove wrinkles in fabrics cleaned or dyed with perc or other glycol ethers, and at the same time feel softer. This is a significant commercial advantage for dry-cleaning establishments.
Other features of the present invention will be pointed out in the following description and claims, which disclose the principles of the invention and the best modes which are presently contemplated for carrying them out.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been found that when dipropylene glycol tertiary-butyl ether (DPTB) is used in the dry-cleaning of garments, the solvent possesses all of the attributes associated with perchloroethylene and none of its drawbacks. Furthermore, DPTB also has certain significant advantages not possessed by perchlorethylene. The DPTB compositions of the present invention are non-flammable, non-combustible, non-carcinogenic, non-toxic and, of the utmost import, biodegradable. The compositions weigh less than water, i.e., the specific gravity is less than that of water.
Advantageously, the flashpoint of DPTB is higher than that of other glycol ethers used as dry-cleaning solvents. The DPTB compositions of the present inventions have even higher flashpoints. Yet the solvent can still be reclaimed and purified via conventional distillation processes, including vacuum distallation, and despite having a higher flashpoint, the solvent is still effective in the removal of water-soluble stains.
DPTB has been discovered to be sufficiently water-compatible to absorb water from garments being dry-cleaned, so that the water component is effectively tied-up, thus avoiding the tendency of woolen garments to shrink, while simultaneously preventing damage to acetates.
It has also been determined that solutions of DPTB and water are effective in the cleaning of scoured and milled raw wool, as well as in the scouring of raw wool, which involves the pulling of oils and fatty acids, e.g. lanolin, from the wool and in the milling of yarns formed thereform. Such scouring and milling operations are conducted in dry-cleaning machinery employing otherwise conventional scouring and milling techniques.
A particular advantage of the DPTB-water solutions of the present invention in dry-cleaning is that they do not behave like a typical mixture, but rather, the behavior is the same as a single substance. This permits a better defined separation upon azeotropic distillation at a lower boiling point and also facilitates reclamation more effectively, at a level of 99% or greater, and also enhances purification using conventional distillation techniques.
Of particular note, from an economic as well as an operational standpoint, is the ability of DPTB to separate from water by azeotropic distillation. This is of particular significance in dry-cleaning because garments entering a dry-cleaning plant contain water in the form of moisture. As noted above, if water were not absorbed by DPTB, damage to woolen and acetate garments would occur. If the absorbed water could not then be separated from the DPTB by azeotropic distillation, the solvent would be diluted with free water and, thus, the dry cleaning process, and its efficiency, would be seriously compromised, as would the reclaimability of the DPTB.
Furthermore, DPTB out-performs both PTB and PNB from the perspective of having an optimum combination of elevated flashpoint and water retention. This combination prevents the bleeding of the most fugitive dyes. Yet, the degree of moisture retention has surprisingly been found to be more than adequate to complete the cleaning process, but well below levels that promote the shrinkage of woolen garments. Additionally, the limited degree of miscibility avoids dilution of the solvent stock with its dependent problems, which are not inconsiderable when one considers the need to replenish the solvent.
DPTB is a very effective dry-cleaning solvent because its detergency action breaks down solvent-soluble (water-insoluble) stain, which account for 15% of all stains found in garments and which are caused by fatty acids. The detergency of the solvent occurs by lifting the soiled area from a surface and by displacing it with surface active materials that have a greater affinity for the surface than they do for the soiled area. Yet at the same time, DPTB also deals most effectively with water-soluble stains, which account for more than 80% of stains encountered in dry-cleaning, such as, for example, stains from fruit, blood, urine, sweat, etc. Despite this affinity for water-soluble materials, DPTB has been found to be most effective in limiting the bleeding of dyes and avoiding the shrinkage of man-made polymers, such as acetates. In comparison to other glycol ethers such as PTB and PNB, the PTB exhibits an unexpectedly superior combination of detergency action toward solvent-soluble stains and affinity for water-soluble stains.
The DPTB compositions of the present invention dry at a relatively low temperature, namely, about 55° C. This is well within the drying requirements for fabrics constructed of fine yarns so as to avoid damage thereto by excessive heat.
In preparing the compositions of the present invention, DPTB is combined with an amount of water up to the maximum quantity soluble in the DPTB at room temperature. Ambient conditions may already have resulted in the DPTB being saturated with water. If not, water may be added to the DPTB to obtain the desired weight ratio of solvent and water, i.e., but never less than about 9:1. Significantly, the quantity of DPTB can be maintained at this level without damage to acetate fabrics or increased bleeding of dyes. Even if the weight ratio of solvent to water approaches 9:1, DPTB is still an effective dry-cleaning solvent. Most preferred is the use of about 90% by weight of DPTB and about 10% by weight of water, which provides the best dry-cleaning result from the perspective of the removal of both solvent-soluble and water-soluble stains, combined with the most efficient and cost-effective dry-cleaning operation.
While DPTB can quite successfully and efficiently clean garments made of all types of textile fabrics without the need for additional agents, such as detergents and fabric softeners, it may be desirable to include in the formulation one or more surfactants to enhance the detergency action of the DPTB or PNB, by means of reducing the surface tension of the composition. Exemplary surfactant include fatty alcohol polyethylene glycol ethers, linear primary alcohol ethoxylates and cyclic siloxanes. Other glycol ethers suitable for use as dry-cleaning solvents may be added as well, including PTB and PNB. Thus, dry-cleaning compositions according to the present invention may include less than 90% by weight of DPTB, provided that the weight ratio of DPTB to water remains greater than about 9:1. Compositions according to the present invention may contain as little as 50% by weight of DPTB, or even less, or any quantity between 50% and 100% by weight, i.e., 55 weight %, 60 weight %, 65 weight %, etc.
While fabric softening agents are not necessary to achieve dry cleaning, they are beneficial and serve to enhance the dry cleaning process. Thus, compositions according to the present invention may also include an effective amount of one or more fabric softening agents.
It has also been determined that the DPTB compositions of the present invention are effective solvents for water-insoluble dyes and the dyeing of fabrics. Dye compositions can be prepared by dissolving aliphatic glycol ether-soluble dyes in the DPTB compositions of the present invention. Dyes that are water-insoluble but soluble in aliphatic glycol ethers can be readily identified by those of ordinary skill in the art without undue experimentation by performing simple solubility testing. Classes of water-insoluble dyes include basic or cationic dyes, dispersed dyes and vat dyes. Dye compositions are prepared by heating an effective amount of the dye with the DPTB composition of the present invention, with mixing until the dye is completely dissolved in the DPTB composition.
Fabric dying can be conducted using conventional dyeing equipment, or by using dry-cleaning machinery. The DPTB composition of the present invention as a solvent for the dye not only functions to dissolve the dye, it also promotes the penetration of the dye into the fabric fiber to form a stronger bond between the dye molecule and the fabric fiber.
After the dyeing is completed, the fabric is dried by essentially conventional techniques. Fabrics dyed with aliphatic glycol ether-soluble dyes dissolved in the DPTB compositions of the present invention exhibit faster drying times than fabrics dyed with water-based dyes. However, the greatest advantage is that the DPTB compositions of the present invention permit the use of water-insoluble dyes to dye fabrics that are colorfast when the dyed fabrics are subsequently washed in water.
EXAMPLES
The following examples are set forth to illustrate more clearly the principles and practice of the present invention. It is to be understood, of course, that the invention is not limited to the specific examples.
EXAMPLE 1
One of the most significant properties that a dry-cleaning solvent should possess is limited fiber shrinkage to ensure that the fibers comprising the garment do not shrink excessively. Excessive shrinkage deforms the garment rendering it unsuitable for future wear. Accordingly, the dry cleaning solvent which is employed must not excessively shrink the component fibers which comprise the fabric of the garment. In contemporary usage, garments containing virgin wool and acetate, such as the lining found in men's jackets, can ill afford shrinkage beyond established norms.
A shrinkage test was conducted with respect to virgin wool by taking a series for of 4″×4″ patterned virgin wool swatches and immersing then in separate containers containing each of the solvents set forth in Table I below. Approximately 10 minutes of mechanical action was applied to ensure that the wool fibers became totally saturated. The test swatch was then removed and dried at constant temperature not exceeding 55° C. The test swatch was then compared with a control material to identify any changes in the fibers to ensure that the patterns had not changed their dimensions.
Each of the test solvents was then analyzed to identify any fiber lost. The maximum shrinkage should not exceed 2% on the first immersion test and is usually expected to be less than 0.25% in any subsequent immersion test.
TABLE I
% Shrinkage
Solvent
on 1 st Immersion
PM
2%
(Propylene glycol methyl ether)
PNP
2%
(propylene glycol n-propylether)
DPM
2%
(dipropylene glycol methyl ether)
PERC
2%
(perchloroethylene)
PTB
½%
(propylene glycol tertiary-butyl ether)
DPTB
<½%
(dipropylene glycol tertiary-butyl ether)
EXAMPLE 2
A shrinkage test conducted in Example 1 was repeated with 4″×4″ swatches of acetate fabric. The results are set forth below in Table II, wherein it is evident from an examination of the results therein, and in Table I, that dipropylene glycol tertiary-butyl ether (DPTB) mixtures resulted in the smallest percentage of shrinkage in both virgin wool and acetate fabrics, and, in fact, reduced shrinkage by about 400% or greater compared with the other solvents, including perc, when employed with virgin wool, and an even greater percentage when employed with acetate fabrics.
TABLE II
PM
3%
(propylene glycol methyl ether)
PNP
3%
(propylene glycol n-propel ether)
DPM
2-5%
(dipropylene glycol methyl ether)
PERC
2%
(Perchloroethylene)
PTB
½%
(propylene glycol tertiary-butyl ether)
DPTB
<½%
(dipropylene glycol tertiary-butyl ether)
EXAMPLE 3
The bleeding of dyestuffs is the bane of the dry cleaner's existence. The variety of dyestuffs, their differing chemical structures, the degree to which they are soluble or insoluble in the particular dry cleaning solvent employed, and the like, present manifold problems which must be met, addressed and solved before a new dry cleaning solvent can be introduced successfully.
Dye bleeding tests were conducted by taking test swatches of virgin wool, 1 inch×1 inch, and immersing them in separate containers filled with each of the azeotropic solvent mixtures indicated in Table III below. Ball bearings were added to each of the containers to increase the impact of mechanical action on the dyes in an effort to dislodge the dyes from the fabric. Increased mechanical action was applied for a period of ten minutes. Thereafter, the test swatch and the ball bearings were removed from the solvent. Colorimeter tests employing a Bausch & Lomb SPEC 20 colorimeter were conducted on the solvent remaining, which serves to indicate the relative quantity of dye removed from the test swatch. The results are set forth in Table III with respect to the various solvents tested on virgin wool swatches which have been dyed red, green, yellow, blue and purple, respectively. The greater the value, the greater the degree of dye bleeding.
TABLE III
DYE BLEEDING
Solvent
Red
Green
Yellow
Blue
Purple
PM
8
7
7
8
8
PNP
6
4
4
5
6
DPM
6
3
5
5
6
Perc
2
2
1
1
3
PTB
2
1
1
1
3
DPTB
<2
1
1
1
2
EXAMPLE 4
In similar fashion to Example 3 above, swatches of various colored acetate fabrics were tested to determine dye bleeding in the below-listed solvents. The results are set forth in Table IV below.
TABLE IV
DYE BLEEDING
Solvent
Red
Green
Yellow
Blue
Purple
PM
9
8
9
9
8
PNP
9
8
8
8
8
DPM
8
8
8
9
8
Perc
1
1
1
2
2
PTB
2
1
1
2
2
DPTB
<2
1
1
1
1
It is clearly evident from Tables III and IV that the azeotropic solvent of the present invention, namely, dipropylene glycol tertiary-butyl ether (DPTB), is far superior to PM, PNP and DPM, and is comparable to perc, as respects dye bleeding, whether the fabric employed is virgin wool or acetate. In point of fact, the solvent of the present invention was in each instance, regardless of fabric type or dye color, significantly more effective in preventing the bleeding of dyes when compared with the non-perc solvents.
EXAMPLE 5
A stain removal test was conducted with respect to cotton by taking a series of 12″×12″ test panels of cotton and applying thereto standard stain items as set forth in Table V, which were then cleaned with a perc solution containing soap. Another set of test panels similarly stained were cleaned with the DPTB composition of the present invention without soap. It will be understood by those skilled in the art that the purpose of perc is to act as a carrier for detergents, soaps, water, etc. and that most stains are typically removed by “spotting” prior to the perc dry-cleaning process. The Table V results demonstrate that the use of soaps and “spotting” is less needed with DPTB.
TABLE V
TYPE OF STAIN
PERC W/SOAP
DPTB W/O SOAP
Shoe Polish
50%
50%
Lipstick
60%
70%
Face Powder
100%
100%
Ketchup
40%
60%
Salad Dressing
70%
80%+
Animal Fat
80%
95%
Mascara
90%
90%
Mayonnaise
90%
90%
Coffee
30%
50%
Ink
30%
40%
Motor Oil
80%
75%
Syrup
80%
90%
It is evident with respect to each of the stains enumerated, which are quite typically encountered by dry cleaners, that DPTB performed as well as or better than perc, which is the most prevalent solvent employed in dry cleaning today.
As will be readily appreciated, numerous variations and combinations of the features set forth within the foregoing description and examples can be utilized without departing from the present invention. The foregoing examples are intended to be illustrative only and are not to be deemed as in any way limiting the scope of the appended claims.
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A method for dry-cleaning garments which comprises treating the garments with a mixture of dipropylene glycol tertiary-butyl ether (DPTB) and water for a period of time sufficient to effect dry-cleaning, wherein the weight ratio of DPTB to water is at least 9:1.
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BACKGROUND OF THE INVENTION
In mechanical energy production through internal combustion motors, several different engines have been developed featured by carrying out 4 basic functions or strokes: admission, compression, explosion and exhaust. This type of engine was the invention of August Otto and has been subsequently the subject of several changes. Its basic principles remaining unchanged; these gave rise to engines having 4-valves per piston, 2 sparkplugs per piston, engines with cylinders in line or in V, engines carrying out the 4 functions or strokes in two turns of the piston crankshaft, the so-called 2-stroke engine; also there are engines with pistons divided around a crankshaft, mostly used in aviation, the toric engine as well as others. The Wankel engine at one thee was considered the potential definite substitute of the traditional Otto piston engine, but due to higher fuel consumption, in relation to the traditional engine, forced the idea to be abandoned. There is also the engine that due to over-compression explodes its mixture, such as Diesel engine, and there exist other power plants that have not been proven a challenge to the Otto engine. At present, auto manufacturers and others, are looking for other options to substitute internal combustion engines, for example, electric engines.
SUMMARY OF THE INVENTION
An object of the invention is to use 4 basic strokes: admission, compression, explosion and exhaust, to manufacture a new internal combustion motor plant, characterized by its ability to produce energy within rectangular chambers inside a circular device, whereby the 4 strokes are carried out using rectangular piston blades pivoting at one end and transmitting power through the other end of the piston blades to the pinions via the connecting rods and the crankshafts. These moving pinions, that according to their movement push the rotor, actuate through a gear a fixed pinion or a fixed interior toothed-ring, allowing it to begin a new cycle once a cycle has ended.
In one embodiment of the engine having 4-piston blades, it has the ability to repeat the cycle of admission, compression, and explosion and exhaust cycle once each revolution or turn of the engine, and in the embodiment having 8-piston blades, twice each revolution or turn of the engine. That is, either the pinions traveling across an internal fixed toothed-ring or encircling a fixed pinion with the same relation, 2:1 for the 4-piston blade engine, 4:1 for the 8-piston blade engine and 6:1 for 12-piston blade engine embodiment.
The present invention further relies on a lubrication system where oil comes into through the central portion of the engine by means of a mechanical seal with holes and slots and is evacuated through seals along the periphery of the rotor.
The present invention further includes an air-cooling system, located in the sides or the rotor, provided with turbines allowing for air to pass from one side of the rotor to the other by means of chambers in the fixed portion of the stator. The lubrication system also helps in the cooling due to the hot oil evacuated from the engine passes through a radiator. The engine seals or gaskets are similar to those of the Wankel engine, these seals lowering friction both in the chambers as in the rotor.
The present invention, additionally, is provided with a reinforcing system or additional aid to piston blade displacement by explosion through polarization of the piston blades with positive or negative magnetic charges which are repel or repulsed with its stator, when piston blades are nearer the stator with the same type of positive or negative magnetic charge. The charge of the electromagnet of the stator is increased at the moment that it passes a few degrees from its maximum position through the load yielded by the alternator or dynamo, which is synchronized and distributed by means of timers, electronic panels, thus further lowering fuel consumption.
DESCRIPTION OF THE FIGURES
FIG. 1 shows a schematic side view of a rotary internal combustion engine.
FIG. 2 shows one of the curved rectangular piston blades along with the respective seals.
FIG. 3 shows a front view of a 4-piston blade rotary internal combustion engine.
FIG. 4 shows a side view of an 8-piston blade rotary internal combustion engine.
FIG. 5 shows a front view of an 8-piston blade rotary internal combustion engine.
FIG. 6 shows a front view of the rotor surface with seals.
FIG. 7 shows a side view of the rotor peripheral seal with the stator and air outlet device.
FIG. 8 shows a curved rectangular and magnetized piston blade with the same polarity as the stator.
FIG. 9 shows a schematic side view of a compressor or rotatory vacuum pump type rotary internal combustion engine where piston blades replace pistons in the traditional compressor (Otto system), and is driven by means of its shaft.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a rotary internal combustion engine 100 , where curved rectangular piston blades 200 realize the four strokes: admission 104 , compression 106 , explosion 108 and exhaust 110 . The piston blades are supported at a proximal end 112 while the distal end 114 is transported due to explosion 108 pushing a connecting rod 116 which moves a crankshaft 118 making the pinion 120 rotate, which when supported on the fixed pinion 122 rotates twice per rotation, pushing and making the rotor spin through the bearings 124 which are embedded between rotor lids (not shown), between the crankshaft 118 and the pinion 120 of each piston blade 200 ; the explosion 108 being carried out by 8 sparkplugs 126 arranged in two rows of four sparkplugs 126 . Four curved divided seals (not shown), located in each side over the periphery of the rotor 128 are supported and produce a tight seal with the stator 130 .
FIG. 2 shows a curved rectangular piston blade 200 with a cavity 202 at its base, in proportion to the compression necessary, ranging from 1:1 to 1:15. Also a system of seals is shown, including edge seals 204 , central linear seal 206 and circular seal 208 around the proximal end 112 . In this circular seal 208 and plug seal 210 there are small boxes 212 wherein the ends of edge seals 204 and central linear seals 206 enter, thus gaining a perfect seal for the fin 200 and its chamber is completely sealed in any position.
FIG. 3, along with references to FIG. 1, show how lubrication and cooling takes place. Lubrication takes place by oil 302 going into the engine through external ducts 304 . The engine has a drilled seal with a ring-shaped slot 306 allowing for oil 302 to enter into the inside of the rotor 128 through 4 drilled pipes 308 distributed one per chamber that permanently sprays oil 303 in those areas requiring lubrication and various internal ducts 310 lead pinion lubrication oil to the piston blades 200 Slots 314 located along the length of peripheral seals 312 allow for the evacuation of oil 302 , which pass across slots and ducts (not shown) with the aid of an oil pump. To enhance cooling, hot oil 302 passes through a radiator 318 . The cooling system operates through the air taken in, and sent by turbine 320 from one side of the rotor 128 to the other side, through stator cavernous body 322 where it is received at the other end by a second turbine 324 , which suctions and expels air allowing the suctioning of air, both for admission and for conditioning of the air. The rotor 128 is supported by dual-stoke rolls 326 , which function either horizontally or vertically. These cooling and lubrication systems operate both in the engine shown in FIG. 1 and FIG. 4 .
FIG. 4 shows a rotary internal combustion engine 400 having eight curved and rectangular piston blades 200 , wherein one revolution of the rotor 128 in the stator 130 , requires four revolutions of the pinions 120 inside the fixed internally-toothed ring 402 or the fixed pinion 122 , thereby requiring four turns per revolution and 2 piston blade 200 cycles per turn, that is, twice admission 104 , compression 106 , explosion 108 , exhaust 110 . This engine differs from the engine of four chambers shown in FIG. 1, in that the engine of FIG. 1 has four chambers, four connecting rods 116 , four crankshafts 118 and four pinions 120 . Also, related to the four chamber engine, the pinions 120 are supported either in the fixed internally-toothed ring 402 or in the fixed pinion 122 . The rotary internal combustion engine 400 lowers rotor 128 velocity relative to that in FIG. 1, but with increased power.
FIG. 5 shows a rotary internal combustion engine 400 in a front view having eight curved and rectangular piston blades 200 . The engines major feature is the way pinions 120 are geared in the fixed internally-toothed ring 402 with a 4:1 ratio. It is outfitted with mechanical seals 404 keeping oil 302 from coming out when entering through mechanical seals 404 and passes from pinions 120 to piston blades 200 by means of internal ducts 310 distributing and expelling oil 303 through the same systems displayed in FIG. 3 .
FIG. 6 shows a portion of the rotor surface 128 where one can see how peripheral seals 312 are arranged with longitudinal holes 328 , these seals and the transverse seals 408 are aligned at their ends by means of plug seals 210 , which have seal boxes 212 that tightly align with the seals and thus achieving a perfect seal with minimum friction.
FIG. 7 shows a cross-sectional rotor 128 and its circular seal 208 located between rotor 128 and stator 130 . This seal is provided with longitudinal slots 702 disposed along the external duct 304 , and allowing for the oil 302 to be evacuated through the expulsion cavity 704 by means of the oil pump 316 and centrifugal force.
FIG. 8 shows a fin 200 magnetized with positive and negative charges and a stator 130 having a series of independent electromagnets 802 magnetically energized, either positively or negatively for the purposes of repelling or attracting in relation to the necessary position of the fin 200 . Additionally, negative or positive charges may be concurrently activated to quickly brake the rotor 128 , all this based on the magnetic principle that same charges are repelled and contrary charges attracted.
FIG. 9 shows a compressor and/or vacuum pump type rotary internal combustion engine 900 where piston blades 200 perform two expansion cycles 902 and two contraction cycles 904 . Such piston blades 200 are transported due to torsion resulting from a power plant taking the power from the central shaft 906 , pushing the crankshafts 118 , putting into motion the connecting rods 116 due to pinion 120 motion of the crankshaft 118 which are moved through bearings 124 , which when displaced due to torsion actuates the central shaft 906 rotating the pinions 120 when supported by the fixed pinions 122 rotating twice per turn. In the entrances of expansion 902 and contraction 904 are located valves, such as check valves that allow for ingress and egress of air.
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A rotary engine having at least two piston blades that may be actuated by either internal combustion or electromagnetic actuation. The combustion engine includes piston blades having a toothed moving pinion connected to each piston blade and a toothed fixed pinion geared to the toothed moving pinions. The gear ratio of the toothed fixed pinion to the toothed moving pinions is one half the number of piston blades to one.
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BACKGROUND OF THE INVENTION
The present invention relates to apparatus for controlling the level of a liquid in a container.
In particular, the present invention relates to apparatus for controlling the level of lubricating oil in the oil pot of a motor, the invention having particular application to reactor coolant pump motors in nuclear power plants.
The reactor coolant pump motors drive the reactor coolant pumps which are part of the reactor coolant system in a nuclear power plant. The motors are typically arranged with vertical shafts. The bearing and lubrication system of a vertical motor is usually contained in two separate oil pots. An upper oil pot contains the upper guide or radial bearings and the total thrust bearing system. A lower oil pot contains the lower guide or radial bearings. Each of these oil pots is typically provided with cooling coils for carrying cooling water to dissipate the heat which is generated by the bearing systems.
The design of the oil pots is such that the oil level within the pot should be monitored during operation to ensure that the oil level is not rising above or falling below expected levels. A rising level might indicate, for example, a water leak within the cooling coils which results in water entering the pot and mixing with the oil. If such a situation were to persist, the lubricating ability of the oil would be sharply diminished and, more importantly, the oil/water mixture would overflow the pot and migrate toward the hot reactor coolant pump, where a fire would almost certainly result.
A falling level would be indicative of a leak in the oil pot system which allows oil to escape from the pot. If this situation persists, the level of the oil in the pot will drop below the level where the oil lubricates the bearings and thus result in severe damage to the bearings and possibly to the motor shaft/runner. More importantly, this condition could also result in a fire if the oil, with a flash point of 420° F. reaches the pump surfaces which may be as hot as 550° F.
Because of these very real and serious concerns, each of the two oil pots is equipped with an oil level detector which provides an alarm signal to a control room in the event of an unusual oil level condition. Some concern exists that the detector may generate a high level alarm when, in fact, the system is operating normally, i.e., there is no leakage of water into the oil pump. A major contributor to this potential problem, particularly with respect to the lower oil pot, is the expansion of the oil due to heat entering the oil pot from the reactor coolant pump. A temperature rise of 50° F. in the oil of the pot, for example, would result in a volume expansion of approximately 0.6 gallon in a 30-gallon capacity pot. This is reflected in the rise of the oil level within the pot and the detector of 0.5 in or more, and could result in a spurious high level alarm signal.
SUMMARY OF THE INVENTION
It is a general object of this invention to provide an improved oil pot arrangement for a vertical shaft pump motor which avoids the disadvantages of prior arrangements while affording additional structural and operating advantages.
An important object of this invention is the provision of oil level control apparatus for a pump motor oil pot which minimizes the effects of thermal expansion of the oil.
In connection with the foregoing object, it is another object of this invention to provide an oil level control apparatus which provides an increase in the effective surface area of the oil pot in response to an increase in the volume of the oil contained therein.
It is another object of this invention to provide an oil level control apparatus of the type set forth which minimizes the chance of spurious high level alarm signals.
In connection with the foregoing objects, it is another object of this invention to provide an oil level control apparatus of the type set forth, which is of simple and economical construction and contains no moving parts and consumes no power.
These and other objects of the invention are attained by providing apparatus for controlling the level of bearing lubricating oil in the oil pot of a nuclear reactor coolant pump motor which has a predetermined normal oil level, the apparatus comprising: container means having a surface area which is relatively large in comparison to its depth, the container means having a flat planar bottom surface disposed substantially at the normal oil level of the oil pot, and means providing liquid communication between the oil pot and the container means so as to equalize the oil levels therein, whereby an increase in the volume of the oil produces an increase in the oil level inversely proportional to the surface area of the oil in said container means.
The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.
FIG. 1 is a fragmentary elevational view, in partial section, of a reactor coolant pump motor incorporating the oil level control apparatus of the present invention;
FIG. 2 is an enlarged fragmentary view in vertical section of the lower portion of the pump motor of FIG. 1, illustrating the present invention;
FIG. 3 is a fragmentary top plan view of the portion of the pump motor illustrated in FIG. 2, with portions broken away more clearly to show the structure of the present invention;
FIG. 4 is a diagrammatic view of the lower oil pot of a prior art reactor coolant pump motor, with the oil therein at a normal level;
FIG. 5 is a view similar to FIG. 4, illustrating the oil level after thermal expansion of the oil;
FIG. 6 is a view similar to FIG. 5, and illustrating the oil level after thermal expansion of the oil with the present invention; and
FIG. 7 is a reduced fragmentary view in horizontal section, taken generally along the line 7--7 in FIG. 1, and illustrating the present invention around the entire circumference of the pump motor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 7 of the drawings, there is illustrated a reactor coolant pump motor, generally designated by the numeral 10, which is of conventional construction. The motor 10 includes a vertical shaft 11 on which is mounted a rotor core assembly (not shown) surrounded by a stator core assembly 13 which is supported between lower and upper brackets 14 and 15. The upper end of the shaft 11 carries a flywheel 16 mounted within a flywheel cover 17. The shaft 11 is provided with upper and lower annular runners 18 and 19.
The upper runner 18 extends into an annular upper oil pot 20 encircling the shaft 11 and is disposed for engagement with an up-thrust bearing 22, and down-thrust bearing 23 and an upper guide bearing 24, all disposed within the upper oil pot 20. The lower runner 19 extends downwardly into an annular lower oil pot 30 which encircles the shaft 11 and is supported on a plurality of equiangularly spaced-apart lower support webs 25, the webs 25 being interconnected by an annular support plate 26 and by cylindrical connecting webs 27 (see FIG. 7).
Referring also to FIGS. 2 and 3 of the drawings, the lower oil pot 30 includes a cylindrical outer wall 31 and a cylindrical inner wall 32, the walls 31 and 32 being interconnected by an annular bottom wall 33. Fixedly secured to the outer wall 31 at the upper edge thereof is a circular head rail 34 which supports thereon an annular seal 35, a gasket 36 being provided therebetween (see FIG. 2). The seal 35 is disposed in sealing engagement with the runner 19 of the shaft 11. Carried by the head rail 34 within the oil pot 30 is a support ring 37. A plurality of bearing shoes 38 are disposed for bearing engagement with the outer surface of the runner 19 at equiangularly spaced-apart points therearound, the bearing shoes 38 being respectively held in engagement with the runner 19 by a plurality of adjusting screws 39 carried by the support ring 37.
All of the structure described above is of conventional construction and is provided in prior art reactor coolant pump motors. The lower oil pot for such a prior art motor is disclosed diagrammatically in FIGS. 4 and 5. The oil pot 30 contains a volume of oil 40 which, at ambient temperatures, normally fills the oil pot 30 to a level 41 illustrated in FIG. 4. A plurality of cooling coils 42 carry cooling water through the oil pot 30 for cooling the oil 40 therein. The oil pot 30 communicates at a port 43 in the bottom wall 33 with a conduit 44 which connects through a valve 45 (see FIGS. 2 and 3) to one or more oil level gauges, which may include a float guide 47 and a sight gauge 49 (see FIG. 4). Both of the gauges 47 and 49 are in liquid communication with the conduit 44 so that the oil rises therein to the same level 41 as is present in the oil pot 30. The float gauge 47 carries a floating element which is disposed for magnetically operating high and low sensor switches to indicate abnormally high or low levels of the oil 40 in the oil pot 30. The sight gauge 49 typically includes a transparent window portion so that the level of oil 40 therein can be visibly observed.
The high level indication is to indicate excess fluid in the oil pot 30 which might be occasioned by a water leak within the cooling coils 42, resulting in water entering the oil pot 30 and mixing with the oil 40. Such a high level would typically trigger an alarm signal, since the dilution of the oil 40 would lessen its lubricating ability and, more importantly, as the leak continued the oil/water mixture might overflow the oil pot 30 and contact the hot reactor coolant pump, causing a fire. The low level sensor is for the purpose of indicating a falling oil level in the oil pot 30, which might be indicative of an oil leak. Such a low level would trigger an alarm signal since a continued leak would cause the oil level to drop to the point where the oil no longer lubricates the bearing shoes 38, resulting in severe damage to the bearing shoes and, possibly to the motor shaft 11 and/or runner 19. Furthermore, this condition could also result in a fire if the leaking oil were to contact the hot pump surfaces.
In this prior art arrangement, the oil 40 in the oil pot 30 tends to expand when heated. Indeed, despite the cooling effect of the cooling coils 42, the oil 40 may be heated to such an extent that it expands to a level 41a illustrated in FIG. 5, such that it will actuate the high level sensor in the float gauge 47 setting off a high level alarm. Such an alarm is spurious since it is not occasioned by excess fluid in the oil pot 30.
The present invention is designed to prevent such spurious high level signals. Thus, referring also to FIG. 6 of the drawings, the present invention includes a level control assembly, generally designated by the numeral 50, which comprises a plurality of secondary containers 51 equiangularly spaced apart around the outside of the lower oil pot 30, as is best illustrated in FIGS. 3 and 7. The secondary containers 51 are substantially identically constructed, each including a flat bottom wall 52, a pair of upstanding rectangular end walls 53, part-cylindrical outer and inner side walls 54 and 55 and a flat top wall 56 cooperating to define a substantially closed shallow container, the horizontal dimensions of which are substantially greater than its depth. A vent opening 57 is provided in the top wall 56. Each of the secondary containers 51 is arranged so that the inner surfaces 58 of the bottom walls 52 are disposed substantially horizontally and coplanar with the normal level 41 of the oil 40 in the oil pot 30. The bottom walls 52 are respectively provided with ports 59 which are in fluid communication, respectively through conduits 60, with a connecting conduit 61 (see FIG. 3), which is in turn in fluid communication with the conduit 44. Thus, the oil level in the conduits 60 and the secondary containers 51 is the same as in the lower oil pot 30.
Preferably, the secondary containers 51 are disposed in the annular space between the outer wall 31 of the lower oil pot 30 and the connecting webs 27, and respectively between adjacent ones of the lower support webs 25. The secondary containers 51 are dimensioned so as not to completely close the space between the oil pot 30 and the connecting webs 27, thereby to permit free flow of air therethrough. However, the secondary containers 51 are dimensioned so that the bottom walls 52 thereof cooperate to provide a combined surface area approximately equal to the surface area of the lower oil pot 30.
Thus, it will be appreciated that the level control assembly 50 operates substantially to increase the effective surface area of the lower oil pot 30. Accordingly, when the oil 40 undergoes thermal expansion, the oil level will increase only to a level 41b illustrated in FIG. 6, substantially lower than the level 41a in the prior art apparatus (FIG. 5), because the expanding oil must cover a substantially increased surface area provided by the secondary containers 51. Thus, it will be appreciated that with the present invention the increase in oil level as a result of a given amount of thermal expansion will be inversely proportional to the surface area of the oil in the secondary containers 51. This effectively prevents spurious high level alarm signals as a result of thermal expansion of the oil 40.
While the level control assembly 50 has been disclosed as containing six of the secondary containers 51, it will be appreciated that any desired number could be provided and, similarly, each of the secondary containers 51 could have any desired shape and size, it being necessary only that the secondary containers 51 be in liquid communication with the oil pot 30 so that the oil level is the same in both.
From the foregoing, it can be seen that there has been provided an improved apparatus for controlling the oil level in the lower oil pot of a reactor coolant pump motor, which apparatus is of simple and economical construction, having no moving parts and consuming no power. This apparatus effectively prevents spurious high oil level alarm signals in the lower oil pot of a reactor coolant pump motor.
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A reactor coolant pump motor has an annular oil pot encircling the vertical motor shaft and containing lubricating oil to a predetermined normal level. A plurality of secondary oil containers are equidistantly spaced around the perimeter of the oil pot, each secondary container having a flat planar bottom surface disposed substantially at the normal oil level of the oil pot. A plurality of conduits provide liquid communication between the bottom of the oil pot and the bottoms of the secondary containers. Each secondary container is substantially closed, but vented to atmosphere.
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FIELD OF THE INVENTION
The present invention deals generally with hygienic products and pertains more specifically to toilet accessories.
BACKGROUND OF THE INVENTION
One of the problems which inheres with the use of toilets is when males urinate into toilets. Every day many males experience difficulty ensuring that no urine is misplaced onto the floor, toilet seat, and other areas in a bathroom. This may be due to physical infirmities, entering a phase of potty-training, substance-abuse related issues, or poor concentration or energy. To date, there is no products in the marketplace which adequately address these issues.
Oftentimes, young boys who are just entering into the potty-training phase have difficulty ensuring all of their urine is deposited completely into the toilet and not on the floor, toilet seat cover, etc. Unfortunately, it may take weeks, if not months to properly train a young boy to successfully use the toilet for urination.
For older men it may be challenging to ensure that all of the urine is deposited into the toilet. Many older men suffer from poor balance, arthritic knees, body control, stamina, and other penile-related maladies. As a result, oftentimes urine is misplaced on the floor, toilet seat cover, etc.
Moreover, other men may experience similar problems due to injuries or other health related issues. Men whom are young and old with crutches, substance abuse-related problems, penile maladies, mental retardation, recent hospital patients, etc. may experience similar issues. Therefore, poor urination abilities are not necessarily confined in scope to just the young or infants. These issues may also afflict many men across the spectrum.
Therefore, what is clearly needed in the art is a device or article of manufacture designed specifically for the use of channeling or funneling urine into a toilet for males. Such a device should be lightweight, pliable, sanitary, and easy to use.
SUMMARY OF THE INVENTION
The present invention in some preferred embodiments consists of a toilet splash guard for use with toilets comprising: a generally flat, planar polyethylene shield, the shield comprising a front side and a rear side, two ends, two circular orifices, indicia, and three polyethylene bumpers, the front side faces the user, the two ends shaped as flanges shaped to correspond to the lower portion of a rim of a toilet, the circular orifices located substantially upon the upper portion of the shield, the bumpers located substantially on the lower portion of the shield, the bumpers located on the rear side of the shield, the bumpers are shaped to correspond with an upper portion of a rim of a toilet bowl, the left bumper and right bumper are shaped diagonally to correspond with the upper portion of a rim of a toilet, the center bumper substantially shaped as a rectangle.
Preferred embodiments may vary with the present invention. Although the aforementioned preferred embodiment was described with many components, the summary of the invention should not be construed to be limiting the scope of the present invention. Several of these components may be optional depending upon the circumstances.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a perspective view of a preferred embodiment of the present invention.
FIG. 2 is a planar view of a preferred embodiment of the present invention.
FIG. 3 is a planar view of a preferred embodiment of the present invention.
FIG. 4 is a perspective view of a preferred embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
According to a preferred embodiment of the present invention, a unique article of manufacture or device is used to prevent urine from being misplaced when aimed at a toilet. The present invention is used primarily for use with males. The article of manufacture or device is described in enabling detail below.
FIG. 1 illustrates a preferred embodiment of the present invention. The toilet splash guard 100 is a generally flat, planar, and bell shaped device which is pliable enough in order to fit into a toilet bowl. In its general use, the toilet splash guard 100 is placed in a similar fashion as seen in FIG. 1 . When a male urinates, the toilet splash guard 100 channels or funnels the urine into the toilet, thus eliminating unsightly urine from being misplaced throughout a bathroom. The toilet splash guard 100 can be generally described as a shield, or a urine shield.
The toilet splash guard 100 will be described herein by different regions and/or parts thereof. The toilet splash guard 100 is comprised of a left rim edge 101 , a right rim edge 102 , a left bumper 103 , a center bumper 104 , a right bumper 105 , a right hole 106 , a left hole 107 , and indicia 108 .
The toilet splash guard 100 is generally a one-piece device or article of manufacture. The only pieces or components which may be added or subtracted are the left bumper 103 , the center bumper 104 , the right bumper 105 , the left hole 107 , the right hole 106 , and the indicia 108 .
The toilet splash guard 100 in a preferred embodiment is made of a flexible, thin, low-density, plastic polyethylene. There are many reasons why polyethylene is an expedient material to comprise a preferred embodiment of the present invention. First, polyethylene is very pliable when cut into relatively thin sheets. In terms of the present invention, relatively thin shall mean a thickness of less than an inch. This is important because the present invention calls for the user to bend the toilet splash guard 100 in such a way to fit into the rim of a toilet bowl. One advantage of the present invention is the fact that the flat and planar toilet splash guard 100 may fit into almost any sized and shaped toilet bowl because the pliability of the toilet splash guard 100 enables it to conform to the rim of just about any toilet bowl. Moreover, when the toilet splash guard 100 is not in use, it may be flattened and stored in a relatively small space.
Another advantage of polyethylene as it relates to the present invention is the fact that it is a sanitary material which can withstand harsh chemicals. Generally, a user will disinfect and spray the toilet splash guard 100 in order to remove residual urine and to remove the malodorous smells associated with urine.
Yet another advantage of using polyethylene is the fact that it is soft to the touch. This is important because one of the objects of the present invention is to enable young children to use the toilet splash guard for their own personal use. Other materials may be too coarse and produce sharp and jagged edges which may create a safety issue.
Although the use of polyethylene is strongly recommended for use with the present invention, other expedient materials may also be used which incorporate the same or similar inherent characteristics mentioned above. Although the inventor is not aware of such substitute materials, it is foreseeable that such materials may be available. As such, the present invention should not be construed to be limiting in scope with respect to the types of materials which are used to comprise the present invention.
Turning now to the present invention, left rim edge 101 and right rim edge 102 are essentially flanges which are used to cooperate with the underside of a rim of a toilet bowl. These two flanges facilitate the affixation of the toilet splash guard 100 to the rim of a toilet bowl.
The left bumper 103 , the center bumper 104 , and the right bumper 105 are used to further facilitate the affixation of the toilet splash guard 100 with the toilet bowl. Whereas the flanges are positioned on the underside of a rim of a toilet bowl, the bumpers are positioned on the upper surface of the rim of a toilet bowl as illustrated in FIG. 4 . Both the left bumper 103 and the right bumper 105 are both cut at an angle as illustrated in FIG. 2 . The reason the left bumper 103 and the right bumper 105 are cut at angles is because as a user bends the toilet splash guard 100 to fit into the rim of a toilet bowl, the bumpers will necessarily contact the rim at an angle. The center bumper 104 is cut straight. The center bumper 104 appears as a box.
The left bumper 103 , the center bumper 104 , and the right bumper 105 are also made of polyethylene. Since polyethylene is not a material well adaptive for use with adhesives, the bumpers are affixed to the outside of the toilet splash guard 100 through heat welding. Essentially the bumper pieces are melted onto the toilet splash guard 100 as cut extrusions. Since the methods used to affix the bumpers onto the toilet splash guard are well known to one skilled in the art, other methods used will not be further detailed herein.
It should be pointed out here that the bumpers are only affixed to one side of the toilet splash guard 100 as illustrated in FIG. 2 . FIG. 3 illustrates the opposite side of the toilet splash guard which does not have the bumpers. For this reason, the toilet splash guard is bent or flexed by the user inwards such that the bumpers are on the outside such that it may be placed upon the upper surface of the rim of a toilet bowl.
Right hole 106 and left hole 107 are used for the purpose of handling the toilet splash guard. The holes may be thought of as handles. Although the illustrated preferred embodiment discloses the use of holes on the top of the toilet splash guard 100 , the use of holes is not specifically required by the present invention. There abound a panoply of different ways of fashioning a handle for the present invention. Therefore, the present invention should not be construed as limiting in scope with respect to the use of holes.
Indicia 108 may embody a panoply of different functions. Indicia 108 may be used as a training device in order to teach young boys in potty training to aim their urine a cartoon character or the like. Games may be incorporated challenging the young boys to aim their urine in specific areas of the toilet splash guard 100 .
In some preferred embodiments indicia 108 may embody static cling vinyl characters. However, there also abound a panoply of ways to imprint or affix indicia 108 to the toilet splash guard 100 which are well known to one skilled in the art. As such, the other methods of affixation of indicia 108 to the toilet splash guard shall not be further detailed herein.
Indicia 108 may also be used for marketing or ornamental purposes. Or, in the alternative indicia 108 may comprise aphorisms, precepts, ideas, or fanciful characters and objects. The uses and embodiments of indicia 108 are endless. However, the use of indicia 108 is not necessary for use with the present invention. In other preferred embodiments, the use of indicia 108 may not be necessary. As such, the present invention should not be construed to be limiting in this regard.
It will be apparent to the skilled artisan that there are numerous changes that may be made in embodiments described herein without departing from the spirit and scope of the invention. As such, the invention taught herein by specific examples is limited only by the scope of the claims that follow.
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A toilet splash guard for use with toilets comprising: a generally flat, planar shield, the shield comprising a front side and a rear side, two ends, at least one orifice, and at least two bumpers, the front side faces the user, the two ends shaped as flanges shaped to correspond to the lower portion of a rim of a toilet, the orifice located substantially upon the upper portion of the shield, the bumpers located substantially on the lower portion of the shield, the bumpers located on the rear side of the shield, the bumpers are shaped to correspond with an upper portion of a rim of a toilet bowl.
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BACKGROUND OF THE INVENTION
[0001] This application is based on and claims the benefit of priority from Taiwan Patent Application 100123030, filed on Jun. 30, 2011.
FIELD OF THE INVENTION
[0002] The present invention relates to wireless local area networks (WLANs), and more particularly, to prevention of unauthorized intrusion into an access point or a wireless client in a WLAN.
DESCRIPTION OF THE PRIOR ART
[0003] Early computers usually communicate with each other with a wired local area network (LAN). However, due to the wide use of mobile devices (such as mobile phones, notebook computers, and personal digital assistants (PDAs)), WLANs have evolved into one of the major ways of communication between computers. WLANs effectuate communication by means of various wireless media, such as radio signals and infrared signals.
[0004] Recent years see the rapid and across-the-board growth of portable computing. In addition to wire connection, portable computing relies heavily on a backbone network and a connected WLAN in order to access various network resources.
[0005] Among a wide variety of WLANs, IEEE 802.11 (also known as WiFi) is in wide and intensive use. IEEE 802.11b,g,n adopt an ISM (Industrial, Scientific, Medical) frequency band that ranges between 2,400 MHz and 2,483.5 MHz. The ISM frequency band is applicable to a spread spectrum system worldwide without requiring a permit.
[0006] FIG. 1 is a schematic view of WLAN authentication of IEEE 802.11 according to the prior art. To start using a wireless local area network (WLAN), a mobile device has to perform message-based communication in three stages, namely probe request 160 /probe response 164 , authentication request 167 /authentication response 172 , and association request 176 /association response 180 , in their order of occurrence in time. The three stages of message-based communication are regulated by IEEE 802.11.
[0007] In the WLAN, a wireless client typically accesses, via an access point, resources available on a backbone network. The backbone network is usually a cable network (such as Ethernet), another wireless network, or a combination thereof. When an access point enables access to the resources available on a cable network, the access point includes at least a cable network interface, a bridge function, and a wireless network interface, so as to performing traffic bridging between a wireless network and the cable network.
[0008] Due to the wide use of WLANs, network security is a concern that is becoming more important. A WLAN effectuates data transmission by means of radio waves. That is to say, any wireless client within a service area covered by an access point can send data to the access point or receive data from the access point. Conventional WLANs enhance user security by means of service set identifiers (SSID), open or shared key identity authentication, Wired Equivalent Privacy (WEP) keys, media access control (MAC), Wi-Fi Protected Access (WPA), etc.
[0009] Compared with a wired local area network, although WLANs manifest greater mobility to users, WLANs attach great importance to communication security. These features of WLANs are especially important, considering that communication security-related issues are absent from the field of wired local area networks.
[0010] For instance, in general, after locating an access point, a wireless client stores its SSID and security (such as WEP or WPA) configuration setting in the wireless configuration of the wireless client. Once the wireless client is connected to the access point again, a wireless device of the wireless client will be automatically connected to the access point.
[0011] However, if a fake access point (fake AP) or a spy access point (spy AP) is in the vicinity of the wireless client and has the same SSID and security configuration setting, or if the spy access point adjusts its wireless connection intensity, the wireless client will be likely to be automatically connected to the spy access point and have its data stolen.
[0012] For example, a hacker can create several fake and spy access points and disguise them as legal hotspots accessible to the general public. The hacker can capture a user's hotspot logging information (username, password, etc.) and other sensitive information, or access the user's shared folders as soon as the user gets connected to the fake and spy access points.
[0013] Hence, what offers a new challenge is about providing a way of maintaining high mobility of WLAN users and still preventing a fake and spy network apparatus from stealing a user's confidential data so as to attain a safe WLAN environment.
SUMMARY OF THE INVENTION
[0014] An aspect of the present invention is to provide an authentication method based on a puzzle/answer mechanism for efficiently preventing a fake network apparatus from stealing a user's confidential data so as to attain a safe WLAN environment.
[0015] Another aspect of the present invention is to provide security-enhancing technology applicable to a wireless local area network (WLAN) in blocking a fake access point/client or a spy access point/client by means of a puzzle/answer protocol, wherein its client and authentication database each have a collection of data entries for enhancing the security of connection between the client and the access point.
[0016] Yet another aspect of the present invention is to provide novel network connection authentication technology whereby each client has its own collection of data entries for communicating and negotiating with an authentication database, wherein the data entries will be deleted from the authentication database when used, so as to prevent unauthorized connection and intrusion effectively.
[0017] An embodiment of the present invention provides a network connection method for use in a wireless local area network (WLAN). The WLAN comprises a client, an access point, and an authentication database coupled to the access point, the authentication database comprising a plurality of collections of data entries. Each of the collections of data entries comprises a plurality of data entries. The network connection method comprises the steps of: receiving by the client one of the collections of data entries in the authentication database; sending a first message carrying an identification tag from the client to the access point; receiving by the access point a second message carrying a query tag, the second message being provided by the authentication database, the query tag being associated with a puzzle, the puzzle being associated with a first data entry of one of the collections of data entries, wherein a first answer to the puzzle is stored in the authentication database and comprises the first data entry; sending a third message carrying the query tag from the access point to the client, the query tag being associated with the puzzle; sending a fourth message carrying an answer tag from the client to the access point and the authentication database, the answer tag being associated with a second answer; and comparing and determining, by the authentication database, whether the first answer and the second answer match, so as to yield a comparison result.
[0018] Before the access point receives the second message, the network connection method further comprises sending a message carrying a puzzle request tag from the access point to the authentication database, so as to request the second message. After the client has sent the fourth message, the network connection method further comprises the steps of: sending a message carrying a compare tag from the access point to the authentication database, so as to compare and determine whether the first answer and the second answer match; and sending the comparison result from the authentication database to the access point.
[0019] The query tag and the answer tag are embedded in an authentication frame. The authentication frame has an authentication header. The authentication header has a frame body field that contains the query tag and the answer tag. The first message comprises a client's MAC address and a tag for authenticating a puzzle/answer protocol in use. The second message comprises a client's MAC address and an access point's MAC address. The third message comprises a client's MAC address. The fourth message comprises a client's MAC address.
[0020] Another embodiment of the present invention provides a computer program product comprising a computer executable procedure step. The computer executable procedure performs network connection in a wireless local area network (WLAN). The WLAN comprises a client, an access point, and an authentication database coupled to the access point. The computer executable procedure step comprises a procedure step for executing the aforesaid method.
[0021] Another embodiment of the present invention provides a client for accessing an access point in a wireless local area network (WLAN). The WLAN comprises the access point, an authentication database coupled to the access point and comprising a program memory for storing a procedure step for executing the aforesaid method, and a processor for executing the procedure step stored in the program memory.
[0022] Another embodiment of the present invention provides an access point accessible to a client in a wireless local area network (WLAN). The WLAN comprises a client, an authentication database coupled to the access point and comprising a program memory for storing a procedure step intended to execute the aforesaid method, and a processor for executing the procedure step stored in the program memory.
[0023] Another embodiment of the present invention provides a wireless local area network (WLAN) comprising a client, an access point, and an authentication database coupled to the access point, wherein the client, the access point, and the authentication database execute the aforesaid method.
[0024] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
[0025] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.
[0027] FIG. 1 is a schematic view of authentication of a wireless local area network (WLAN) according to the prior art;
[0028] FIG. 2 is a schematic view of a system according to a specific embodiment of the present invention;
[0029] FIG. 3 is a schematic view of authentication of a wireless local area network (W LAN) according to a specific embodiment of the present invention;
[0030] FIG. 4 is a schematic view of success of an puzzle/answer transmitted between a wireless client, an access point, and an authentication database of a recipient server according to a preferred embodiment of the present invention;
[0031] FIG. 5 is a flowchart of receiving collections of data entries from an authentication database at a client according to a preferred embodiment of the present invention;
[0032] FIG. 6 is a flowchart of a network connection in a wireless local area network according to a preferred embodiment of the present invention;
[0033] FIG. 7 is a schematic view of a flowchart based on FIG. 5 and FIG. 6 , showing that wireless clients each having separate collections of data entries for performing an enigmatic process according to a preferred embodiment of the present invention;
[0034] FIG. 8 is a flow chart of a state machine of a puzzle/answer mechanism according to a preferred embodiment of the present invention;
[0035] FIG. 9 is a schematic view of an example of the composition of an authentication frame complying with 802.11 protocol and an example of frame control fields in the authentication frame according to a preferred embodiment of the present invention;
[0036] FIG. 10 is a schematic view of communication between a client and an access point applicable to an authentication frame under 802.11 protocol according to a preferred embodiment of the present invention; and
[0037] FIG. 11 is a schematic view of how an access point authenticates the MAC address of each wireless client according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
[0039] As will be appreciated by one skilled in the art, the present invention may be embodied as a computer device, a method or a computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer-usable program code embodied in the medium.
[0040] Any combination of one or more computer usable or computer readable medium(s) may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, 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 hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. 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. 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 medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc.
[0041] Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer or server may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0042] The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, 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/acts specified in the flowchart and/or block diagram block or blocks.
[0043] These computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0044] 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 which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0045] Referring to FIG. 2 , there is shown a schematic view of a method, system, and product for use with a network connection in a wireless local area network according to a specific embodiment of the present invention. As shown in FIG. 2 , a network system 100 comprises a network 168 , a server 120 , a plurality of authorized access points 108 , and a plurality of wireless clients 104 . The wireless clients 104 are each coupled to the network 168 via a connection 170 , a wireless connection/wire connection, or both, so as to communicate with the access points 108 by, including but not limited to, a wireless means. Depending on the size and scope of an apparatus, the aforesaid devices come in different system types and different connection types. The wireless clients 104 are notebook computer systems, personal digital assistant (PDA) systems, mobile phones, smartphones, desktop computers, or other devices capable of accessing the network 168 by means of the authorized access points 108 . FIG. 2 also shows that a plurality of wireline clients 124 usually communicates with the network 168 via a wire connection. The network system 100 further comprises access points and wireless clients other than the access points 108 and the wireless clients 104 .
[0046] FIG. 2 also depicts an unauthorized fake or spy access point 106 disguised as a legal hotspot accessible to the general public. It is likely that the unauthorized fake or spy access point 106 is created by an individual or group when information technology management is kept in the dark about the unauthorized fake or spy access point 106 or gives no consent thereto. As mentioned earlier, the unauthorized fake or spy access point 106 is likely to adjust its own wireless connection intensity or have identical SSID and security configuration setting security; as a result, information related to a user is likely to be stolen as soon as the user gets connected to the access point 106 , thereby compromising the security of WLAN environment.
[0047] FIG. 3 is a schematic view of authentication of a wireless local area network according to a preferred embodiment of the present invention, wherein a frame communication process taking place between the wireless client 104 and the access point 108 is depicted. Referring to FIG. 3 , to access the wireless local area network, the wireless client 104 in an environment sends a probe request (step 212 ). Afterward, the wireless client 104 detects the access point 108 by means of a probe response received by the wireless client 104 from the at least one said access point 108 (step 216 ). After receiving the probe response, the wireless client 104 sends an enigmatic process request (step 220 ) and then waits for an enigmatic process response from the access point 108 (step 224 ). The aforesaid enigmatic process request and enigmatic process response are described in detail later. After receiving the enigmatic response, the wireless client 104 communicates with the access point 108 , using a message of authentication request (step 228 ). At this point in time, the wireless client 104 sends a password to the access point 108 for authentication and then waits for an authentication response from the access point 108 (step 232 ). After the authentication has passed, a link layer-based connection between the wireless client 104 and at least one of the access points 108 is created by means of an association request 236 and an association response 240 . Afterward, the wireless client 104 has to pass authentication of the server 120 , such as an AAA server (authentication, authorization, and accounting server), in order to gain more authority required for accessing network resources. In a preferred embodiment, the wireless client 104 sends to the access point 108 EAP-enabled information (Extensible Authentication Protocol-enable information) under Cross-border Network Extensible Authentication Protocol, and then the access point 108 sends the EAP-enabled information to the server 120 for authentication. After the authentication has passed, the server 120 sends a message to the access point 108 to inform the access point 108 of an EAP success in order to be authorized to receive and send a packet. The aforesaid probe request/probe response, authentication request/authentication response, association request/association response, authorization to access, and authorization to receive and send a packet, which take place between the wireless client 104 and the access point 108 , are governed by IEEE 802.11 or understood by persons skilled in the art and thus are not reiterated herein for the sake of brevity.
[0048] Referring to FIG. 4 , there is shown a schematic view of the process flow of success of an enigmatic puzzle/answer received by a client 104 from an authentication database of the server 120 according to a preferred embodiment of the present invention, wherein the wireless local area network comprises a client 104 , an access point 108 , and a server 120 . The server 120 has an authentication database 660 . The authentication database 660 comprises a plurality of collections of data entries 662 . Each of the collections of data entries 662 comprises a plurality of data entries 662 . First, the client 104 fetches one of the collections of data entries 662 from the authentication database 660 and sets the fetched collection of data entries 662 to a collection of data entries 666 of the client 104 ; hence, the collections of data entries 666 of the client are identical to the collections of data entries 662 of the authentication database 660 . Referring to FIG. 4 , in step 604 , the client 104 performs on the access point 108 a step of requesting connection. In step 608 , the access point 108 performs on the server 120 /authentication database 660 a step of asking an enigmatic puzzle. In step 612 , the server 120 /authentication database 660 performs on the access point 108 a step of sending an enigmatic puzzle. In step 616 , the access point 108 performs on the client 104 a step of asking an enigmatic puzzle. In step 620 , the client 104 performs on the access point 108 a step of giving an enigmatic answer. In step 624 , the access point 108 performs on the server 120 /authentication database 660 a step of requesting a server to judge an answer. In step 628 , the server 120 /authentication database 660 performs on the access point 108 a step of sending answer match and deleting an enigmatic answer from the server 120 /authentication database 660 . In step 632 , the access point 108 performs on the client 104 a step of giving pass notice and sending answer match. The aforesaid acquisition of collections of data entries and enigmatic puzzle/answer process flow are described in detail later.
[0049] FIG. 5 is a flowchart of a method whereby a client receives collections of data entries from an authentication database according to a preferred embodiment of the present invention. FIG. 6 is a flowchart of a method of network connection in a wireless local area network according to a preferred embodiment of the present invention. The wireless local area network comprises the client 104 , the access point 108 , and the server 120 . The server 120 has an authentication database 660 . The authentication database 660 comprises a plurality of collections of data entries 662 . Each of the collections of data entries 662 comprises a plurality of data entries 662 . The server 120 is an authentication server. A network management server (not shown) is also coupled to the authentication server 120 . Each of the access points 108 in the system controls the ability of the client 104 to access the Internet according to a command from the network management server. The main purpose of the authentication server 120 is to confirm the identity of the client 104 and grant access authority to the client 104 . Furthermore, the authentication server 120 stores information related to the client 104 in a database. The aforesaid technology pertaining to the authentication server and the network management server is understood by persons skilled in the art and thus are not reiterated herein for the sake of brevity.
[0050] In a preferred embodiment of the present invention, a plurality of collections of data entries 662 is a plurality of books (or dictionaries, books, and a numeric string), whereas a plurality of data entries within collections of data entries 662 are words (words, characters, word blocks, sentences, sentence blocks, and numbers) in a composite book.
[0051] Referring to FIG. 4 and FIG. 5 , in a preferred embodiment, the client 104 fetches one of the collections of data entries 662 from the authentication database 660 (step 408 ), and then the client 104 sets the fetched collection of data entries 662 to the client's collection of data entries 666 (step 412 ). Hence, the client's collections of data entries 666 are identical to the collections of data entries 662 in the authentication database 660 . The client 104 can fetch the collections of data entries 662 from the authentication database 660 in whatever ways and at any time. For example, the authentication database 660 updates data of the client 104 automatically whenever the client 104 undertakes system installation or when data in a database of the client 104 is going to be used up.
[0052] FIG. 6 is a flowchart of a communication process between the wireless client 104 and the access point 108 /server 120 , using enigmatic process requests and enigmatic process responses, in a wireless local area network according to a preferred embodiment of the present invention. In this embodiment, the network connection is effectuated by means of the system 100 in FIG. 2 .
[0053] Referring to FIG. 4 , FIG. 5 , and FIG. 6 , in step 416 , after confirming that the access point 108 has sent a beacon, the client 104 sends a probe request to the access point 108 . In step 420 , the client 104 receives a probe response from the access point 108 . In step 424 , the client 104 sends to the access point 108 a first message carrying an identification tag. In step 428 , after the client 104 has sent the first message, the access point 108 authenticates a MAC address of the client 104 .
[0054] In step 432 , the access point 108 sends to the server 120 /authentication database 660 a puzzle request message carrying a puzzle request tag. In step 436 , the access point 108 receives a second message carrying a query tag, wherein the second message is provided by the server 120 /authentication database 660 . In a preferred embodiment, the query tag is associated with a puzzle, and the puzzle is associated with a first data entry of one of the collections of data entries. A first answer to the puzzle is stored in the authentication database 660 and includes the first data entry. The puzzle comprises an index or position of the first data entry in the collections of data entries.
[0055] In step 440 , the access point 108 sends to the client 104 a third message carrying the query tag, and the query tag is associated with the puzzle. In step 444 , the client 104 sends to the access point 108 a fourth message carrying an answer tag, and the answer tag is associated with a second answer. In step 448 , the access point 108 sends to the server 120 /authentication database 660 a message carrying a compare tag to compare and determine whether the first answer and the second answer match so as to yield a comparison result. In step 452 , the server 120 /authentication database 660 determines whether the comparison result is a match.
[0056] In step 456 , if the comparison result is a match, the server 120 /authentication database 660 will send the comparison result to the access point 108 and delete the first data entry from the server 120 /authentication database 660 ; afterward, the access point 108 sends the comparison result to the client 104 to inform the client 104 of a result of an enigmatic pass, thereby connecting the client 104 and the access point 108 . Upon completion of the aforesaid handshaking, the client 104 and the access point 108 start executing a connection procedure of IEEE 802.11.
[0057] In step 460 , if the comparison result is not a match, the client and the access point will not be connected together. In a preferred embodiment, the Internet protocol address of a fake access point and a spy access point can be invalidated. For example, the client's MAC address is not found in an approval checklist, and a spy access point cannot judge the identification tag.
[0058] FIG. 7 is a flowchart based on FIG. 6 according to a preferred embodiment of the present invention, showing wireless clients 104 A, 1048 , 104 C which have independent collections of data entries 666 , 670 , 674 , respectively, wherein the independent collections of data entries 666 , 670 , 674 are provided by the server 120 to perform an enigmatic process. The independent collections of data entries are created according to the MAC address, whereas the independent collections of data entries are arranged by a system installation worker of the client 104 . Alternatively, if the data in the database of the client 104 are going to be used up, the authentication database 660 will automatically update the data of the client 104 and maintain a specific size. The way of authenticating the MAC addresses of wireless clients by the access point is further described later.
[0059] FIG. 8 is a flow chart of a state machine of a puzzle/answer mechanism according to a preferred embodiment of the present invention. Referring to FIG. 8 , each state is described below. State 1 ( 704 ): a client requests connection (assertion) and sends a connection request ( 708 ). State 2 ( 712 ): an access point makes a query (challenge) and sends the query ( 716 ), wherein, if time>N (such as three cycles) and has not sent the query, then go to state 1 ( 717 ). State 3 ( 720 ): the client gives a response, wherein, if time>N (such as three cycles) and has not sent the response, then go to state 1 ( 724 ), otherwise send a result and go to state 4 ( 733 ). State 4 ( 733 ): the access point gives pass notice, wherein, if the access point sends the result, then connection succeeds ( 740 ), wherein, if the access point does not send the result, then go to state 1 ( 736 ).
[0060] FIG. 9 is a schematic view of an example of the composition of an authentication frame complying with 802.11 protocol and an example of frame control fields in the authentication frame according to a preferred embodiment of the present invention. The authentication frame has a format specified in IEEE 802.11 and shown in FIG. 8 , and comprises the following fields: Frame Control field, Duration field, Address 1 , Address 2 , Address 3 , Sequence Control, Address 4 , Frame Body, and CRC (cyclic redundancy check). Frame Control consists of the following fields: Protocol Version, Type, Subtype, To DS, From DS, More Flag, Retry, Power Management, More Data, WEP (Wired Equivalent Privacy), and Order. The aforesaid fields comply with proper values of IEEE 802.11 specifications. In this preferred embodiment, the Type field is configured to display binary numbers: 00 (Management), 01 (Control), 10 (Data), and 11 (these configuration values denote reserved fields under 802.11 protocol, and indicate an enigmatic puzzle type in this specific embodiment.)
[0061] FIG. 10 is a schematic view of communication between a client and an access point applicable to an authentication frame under 802.11 protocol according to a preferred embodiment of the present invention, wherein the diagram illustrates authentication of the contents of a frame body. Step 904 involves declaring using an enigmatic puzzle algorithm in response to an enigmatic puzzle that requests connection. Step 908 involves asking line N's word in response to asking an enigmatic puzzle. Step 912 involves answering line N's word in response to answering an enigmatic puzzle. Step 916 involves responding that the authentication succeeds or fails in response to notifying an enigmatic result.
[0062] FIG. 11 is a schematic view of how an access point 108 authenticates the MAC address of each of the wireless clients 104 according to a preferred embodiment of the present invention. As shown in FIG. 11 , under 802.11 protocol, Address 1 is filled with target MAC address, and Address 2 is filled with source MAC address. Hence, the access point 108 authenticates each of the wireless clients 104 by means of the mechanism of the aforesaid MAC addresses.
[0063] In the preferred embodiments of the present invention, regarding enigmatic authentication communication between a client and an access point, data entries in their collections of data entries 662 are deleted immediately after being used, and thus never repeat, so as to efficiently prevent fake and spy network apparatuses from stealing a user's confidential data according to the prior art. Furthermore, each client has an authentication database conducive to enhancement of security, even though the authentication database is of small dimensions. The present invention complies with the existing 802.11 protocol and thus is easy to implement. According to the present invention, confidential data are accessible to authorized clients and access points only, thereby providing a safe WLAN environment.
[0064] A point to note is that the present invention is not restrictive of the sequence of the steps illustrated with FIG. 3 through FIG. 6 . What are illustrated with FIG. 3 through FIG. 6 are just different examples. Although a fake access point and a spy access point are illustrated with the drawings of the present invention, persons skilled in the art should be able to understand that fake clients and spy clients can be applied in the control of network security in the same way. Related details are not reiterated herein for the sake of brevity, as they are described herein when referring to the drawings of the present invention. Furthermore, clients, access points, and servers in the preferred embodiments of the present invention comply with IEEE 802.11 but are not necessarily so. In practice, various protocols are applicable to the present invention efficiently.
[0065] The foregoing preferred embodiments are provided to illustrate and disclose the technical features of the present invention, and are not intended to be restrictive of the scope of the present invention. Hence, all equivalent variations or modifications made to the foregoing embodiments without departing from the spirit embodied in the disclosure of the present invention should fall within the scope of the present invention as set forth in the appended claims.
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Disclosed is a method of network connection in a wireless local area network. The wireless local area network comprises a client, an access point, and an authentication database coupled to the access point. The authentication database comprises a plurality of collections of data entries, wherein each of the collections of data entries comprises a plurality of data entries. The network connection method comprises: passing messages containing queries relating to data entries in the authentication database and receiving responsive answer tags.
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This application is a divisional of prior U.S. patent application Ser. No. 10/299,730 filed on Nov. 19, 2002 now U.S. Pat. No. 7,986,932.
TECHNICAL FIELD OF THE INVENTION
The present invention is generally directed to communication devices, and more specifically, to a finite impulse response (FIR) filter that uses adaptive truncation and clipping in a wireless communication device.
BACKGROUND OF THE INVENTION
In conventional wireless code division multiple access (WCDMA) systems, the power of the adjacent channel could be as much as 40.7 dB higher than the in-band signal power received by the base station or mobile station. This significant difference requires that conventional baseband matched filters have a large dynamic range. Conventional fixed point finite impulse response (FIR) filters typically implement truncation and clipping scheme after the correlation block. The truncation and clipping scheme truncates a fixed number of the least significant bits from the correlator outputs and clips the signal peaks at some fixed saturation level. However, to cope with the large dynamic range of the filter input, conventional fixed point FIR filters typically use more output bits than are required in order to avoid system performance degradation. This problem is unique to fixed point FIR filters, since floating point FIR filters do not require clipping and truncation circuits.
Therefore, there is a need in the art for an improved finite impulse response (FIR) filter that is capable of processing input signals having a potentially large dynamic range without requiring the use of a large number of extra filter output bits to retain system performance. In particular, there is a need in the art for an improved FIR filter having reduced complexity that is able to process input signals having large dynamic ranges wherein size of the FIR filter outputs are optimized for the in-band signal power.
SUMMARY OF THE INVENTION
To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide an improved fixed point finite impulse response (FIR) filter. According to an advantageous embodiment of the present invention, the fixed point FIR filter comprises: 1) an input stage capable of receiving an input signal as a sequence of input samples, the input stage comprising: i) a plurality of delay elements connected in series capable of receiving and shifting N sequential input samples; ii) a plurality of multipliers, each of the multipliers capable of receiving a selected one of the N sequential input samples from the plurality of delay elements and multiplying the selected input sample by a corresponding coefficient to thereby produce an intermediate product; and iii) a summer capable of receiving and adding N intermediate products from the plurality of multipliers to thereby produce an output sum signal comprising a sequence of output sum samples; and 2) an output stage capable of truncating k least significant bits (LSBs) from each of the output sum samples, wherein k is a variable number, to thereby produce a sequence of filtered output samples.
According to one embodiment of the present invention, the output stage comprises: 1) a variable gain amplifier capable of multiplying each of the output sum samples by a variable gain factor to produce a sequence of shifted output samples, wherein a most significant bit of the each output sum sample is shifted a variable amount to a desired bit position; and 2) a feedforward gain controller capable of determining a power of the each output sum sample and, in response to the determination, adjusting the variable gain factor.
According to another embodiment of the present invention, the output stage comprises: 1) a variable gain amplifier capable of multiplying each of the output sum samples by a variable gain factor to produce a sequence of shifted output samples, wherein a most significant bit of the each output sum sample is shifted a variable amount to a desired bit position; and 2) a feedback gain controller capable of determining a power of each filtered output sample and, in response to the determination, adjusting the variable gain factor so that an optimum number of the filtered output samples are saturated.
According to still another embodiment of the present invention, the output stage comprises: 1) a variable truncation unit capable of truncating a variable number, k, of least significant bits from each of the output sum samples to thereby produce a sequence of truncated samples; and 2) a feedforward gain controller capable of controlling the variable truncation unit, wherein the feedforward gain controller determines a power of the each output sum sample and, in response to the determination, adjusts the variable number, k.
According to yet another embodiment of the present invention, the output stage comprises: 1) a variable truncation unit capable of truncating a variable number, k, of least significant bits from each of the output sum samples to thereby produce a sequence of truncated samples; and 2) a feedback gain controller capable of controlling the variable truncation unit, wherein the feedback gain controller determines a power of the each filtered output sample and, in response to the determination, adjusts the variable number, k.
According to a further embodiment of the present invention, the output stage further comprises a truncation unit capable of is receiving the sequence of shifted output samples from the variable gain amplifier and truncating a fixed number of least significant bits from each shifted output sample to thereby produce a sequence of truncated samples.
Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand is that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
FIG. 1 illustrates a wireless communication device according to an exemplary embodiment of the present invention;
FIG. 2 illustrates a finite impulse response (FIR) filter according to an exemplary embodiment of the prior art;
FIG. 3 illustrates a finite impulse response (FIR) filter according to a first exemplary embodiment of the present invention;
FIG. 4 illustrates a finite impulse response (FIR) filter according to a second exemplary embodiment of the present is invention;
FIG. 5 illustrates a finite impulse response (FIR) filter according to a third exemplary embodiment of the present invention;
FIG. 6 illustrates a finite impulse response (FIR) filter according to a fourth exemplary embodiment of the present invention;
FIG. 7A illustrates a feed-forward calculation block for adaptively determining the truncation value according to an exemplary embodiment of the present invention; and
FIG. 7B illustrates a feedback calculation block for adaptively determining the truncation value according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 through 7 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged wireless communication system.
FIG. 1 illustrates wireless communication device 100 according to an exemplary embodiment of the present invention. Wireless communication device 100 is intended to be a generic representation of any type of receiver that may contain a fixed point finite impulse response (FIR) filter using adaptive truncation according to the principles of the present invention. Thus, in one embodiment of the present invention, wireless communication device 100 shown in FIG. 1 may be a portion of a cellular telephone or a portion of a base station of a wireless network. In an alternate embodiment of the present invention, wireless communication device 100 may be part of a wireless network card in a personal computer (PC) operating in, for example, an IEEE 802.11 compatible wireless local area network (LAN). Those skilled in the art will recognize that the particular details set forth below with respect to wireless communication device 100 are by way of example only and should not be construed so as to limit the scope of the present invention.
The receive path of wireless communication device 100 comprises antenna 105 , variable gain amplifier (VGA) 110 , radio frequency (RF) filter 115 , quadrature phase shift keying (QPSK) demodulator 120 , analog-to-digital-converters 125 A and 125 B, and automatic gain control (AGC) block 130 . The receive path of wireless communication device 100 also comprises fixed point finite impulse response (FIR) filters 135 A and 135 B and demodulator block 140 .
Variable gain amplifier (VGA) 110 amplifies the incoming RF signal receive from antenna 105 by an amount determined by gain control signal receive from AGC control block 130 . RF filter 115 then filters the output of VGA 110 . According to an exemplary embodiment of the present invention, RF filter 115 may be any one of several infinite impulse response (IIR) filters that have the primary function of isolating the frequencies of interest (i.e., band selection, channel selection, low-pass filtering) and perform anti-aliasing for ADC-sampling.
QPSK demodulator 120 then demodulates the filtered RF signal to produce an intermediate frequency (IF) signal or a baseband signal. According to an exemplary embodiment of the present invention, the incoming RF signal is a quadrature phase-shift keying (QPSK) signal and the outputs of QPSK demodulator 120 are an in-phase (I) output signal and a quadrature (Q) output signal. The in-phase (I) output signal from QPSK demodulator 120 is converted from an analog signal to a digital signal by analog-to-digital converter (ADC) 125 A. The quadrature (Q) output signal from QPSK demodulator 120 is converted from an analog signal to a digital signal by analog-to-digital converter (ADC) 125 B.
The digitized I and Q output signals from ADC 125 A and ADC 125 B are fed back to AGC block 130 . AGC block 130 functions in such a manner that the total power of the in-band signals and the out-of-band adjacent channel signals are maintained at a constant level at the outputs of ADC 125 A and ADC 125 B. The power of the in-band signals at the outputs of ADC 125 A and 125 B is kept constant by AGC block 130 even if there are strong adjacent channel signals.
The outputs of ADC 125 A and ADC 125 B are filtered by fixed point FIR filter 135 A and fixed point FIR filter 135 B, respectively. FIR filter 135 A and FIR filter 135 B are matched filters, so that only the in-band signals remain at the outputs of FIR filter 135 A and FIR filter 135 B. Since the strengths of the in-band signals at the outputs of ADC 125 A and 125 B vary according to the strength of the adjacent channel signals, the power of signals at the outputs of FIR filter 135 A and FIR filter 135 B also vary.
Advantageously, since RF filter 115 is typically a 3 rd or 4 th order Butterworth filter or Chebycheshev filter that provides only about 18-24 dB attenuation at the center of the adjacent channel, fixed point FIR filter 135 A and fixed point FIR filter 135 B also act as an adjacent channel selectivity filters that provide about 40 dB attenuation at the center of the adjacent channel.
Next, demodulator 140 demodulates the in-phase baseband signal to thereby recover the symbols of the in-phase baseband signal. Similarly, demodulator 140 demodulates the quadrature baseband signal to thereby recover the symbols of the quadrature baseband signal. The recovered symbols comprise the Data Out signal at the output of demodulator 140 .
FIG. 2 illustrates fixed point finite impulse response (FIR) filter 200 according to an exemplary embodiment of the prior art. Prior art FIR filter 200 may be used in place of FIR filter 135 A and FIR filter 135 E in FIG. 1 . FIR filter 200 comprises a chain of N−1 sequential delay (D) elements, including exemplary delay (D) elements 201 , 202 , 203 , 204 and 205 . FIR filter 200 also comprises N multipliers, including exemplary multipliers 211 , 212 , 213 , 214 , 215 and 216 . FIR filter 200 also comprises summer 220 , least significant bit (LSB) truncation block 230 and saturation block 240 .
The Data In signal received from ADC 125 A or ADC 125 B comprises a sequence of r-bit digital samples. These r-bit digital samples shift sequentially through the N−1 delay elements, including exemplary delay elements 201 - 205 . The N multipliers, including exemplary multipliers 211 - 216 multiply N sequential samples of the Data In signal by the N filter coefficients c( 0 ), c( 1 ), . . . c(N−1), and c(N).
The intermediate signal at the output of summer 220 comprises a sequence of m-bit digital samples, where m is greater than r. For example, in an exemplary embodiment of the present invention, r may be 6 bits and m may be from 17 bits to 20 bits. In order to reduce the complexity of FIR filter 200 and subsequent stages of wireless communication device 100 , LSB truncation block 230 truncates (i.e., cuts off) the k least significant bits from the m-bit intermediate signal received from summer 220 . Saturation block 240 compares the (m−k)-bit truncated output from LSB truncation block 230 to a maximum threshold and a minimum threshold and outputs a p-bit output at the Data Out signal. If the (m−k)-bit truncated output from LSB truncation block 230 exceeds the maximum threshold, saturation block 230 outputs a maximum saturation value. It the (m−k)-bit truncated output from LSB truncation block 230 is less than the minimum threshold, saturation block 230 outputs a minimum saturation value.
For example, let m=17, k=8 and p=6. LSB truncation block 230 drops the nine (9) least significant bits from the 17-bit intermediate signal from summer 220 and outputs a (17-8)=9-bit value to saturation block 240 . The range of the 6-bit output (p=6) from saturation block 240 is from +31 to −32. Saturation block 240 compares each 9-bit value from LSB truncation block 230 to +31 and −32. If the 9-bit value from LSB truncation block 230 is greater than +31, saturation block 240 outputs a maximum saturation value equal to +31 (i.e., 011111 in 2s-complement). If the 9-bit value from LSB truncation block 230 is less than −32, saturation block 240 outputs a minimum saturation value equal to −31 (i.e., 111111 in 2s-complement). If the 9-bit value from LSB truncation block 230 is between +31 and −32 inclusive, saturation block 240 outputs a 6-bit value equal to the 9-bit output of LSB truncation block 230 .
However, the wide dynamic range of the m-bit output from summer 220 causes problems in the performance of wireless communication device 100 . The above-described operation of FIR filter 200 provides a quantization window having a width of p bits at bit position k. Given a signal power of m bits at the output of summer 220 and a Data Out signal of p bits, the higher the quantization window, the more rounding noise, and the lower the quantization window, the more overflow noise.
There is an optimal window position for the given power of the input signal of m bits at the output of summer 220 . However, while this optimal window position may change, conventional fixed point FIR filter designs use quantization windows that have a fixed width and a fixed bit position. This leads to performance degradation. The present invention overcomes this problem by providing an apparatus that is capable of performing adaptive truncation, wherein the value of k may be modified in order to truncate a variable number of bits from the output of summer 220 .
FIG. 3 illustrates fixed point finite impulse response (FIR) filter 135 according to a first exemplary embodiment of the present invention. FIR filter 135 represents one or both of fixed point FIR filters 135 A and 135 B in FIG. 1 . FIR filter 135 comprises a chain of N−1 sequential delay (D) elements (e.g., shift registers), including exemplary delay (D) elements 201 , 202 , 203 , 204 and 205 . FIR filter 135 also comprises N multipliers, including exemplary multipliers 211 , 212 , 213 , 214 , 215 and 216 . FIR filter 135 also comprises summer 220 , variable gain amplifier 310 , feed-forward control block 320 , least significant bit (LSB) truncation block 230 and saturation block 240 . The input stages of FIR filter 135 , up to and including summer 220 , operate identically to the input stages of FIR filter 200 and need not be discussed in detail again.
However, the m-bit output of summer 220 is multiplied by a variable amount of gain by variable gain amplifier 310 before being applied to LSB truncation block 230 . The amount of gain is controlled by feed-forward control block 320 . Feed-forward control block 320 measures the signal strength of the m-bit output of summer 220 and adjusts the gain (G) of amplifier 310 in order to keep the power of the samples entering LSB truncation block 230 in a desired target range.
For example, if a p=6 bit output (including sign bit) is desired for the Data Out signal and k=7 bits of truncation, then feed-forward control block 320 adjusts the gain of amplifier 310 (up or down), so that the most significant bits of the peaks of the samples entering LSB truncation block 230 are approximately bit positions 12 or 13 , or perhaps bit position 14 (disregarding occasional very large peaks). After the k=7 least significant bits are dropped, the peak values entering LSB truncation block 230 will have their most significant bits in bit positions 5 or 6 , or perhaps bit position 7 (not counting the sign bit). In this manner, most samples at the output of saturation block 240 make full use of the range between +31 and −32 in value without a large number of saturation values being generated.
FIG. 4 illustrates finite impulse response (FIR) filter 135 according to a second exemplary embodiment of the present invention. As in FIG. 3 , FIR filter 135 comprises a chain of N−1 sequential delay (D) elements, including exemplary delay (D) elements 201 , 202 , 203 , 204 and 205 . FIR filter 135 also comprises N multipliers, including exemplary multipliers 211 , 212 , 213 , 214 , 215 and 216 . FIR filter 135 also comprises summer 220 , variable gain amplifier 410 , feedback control block 420 , least significant bit (LSB) truncation block 230 and saturation block 240 . The input stages of FIR filter 135 , up to and including summer 220 , operate identically to the input stages of FIR filter 200 and need not be discussed in detail again.
As in the case of FIR filter 125 in FIG. 3 , the m-bit output of summer 220 is multiplied by a variable amount of gain by variable gain amplifier 410 before being applied to LSB truncation block 230 . However, the amount of gain is controlled by feedback control block 420 (rather than a feedforward controller). Feedback control block 420 , discussed below in greater detail, measures the signal strength of the p-bit output saturation block 240 to determine the number of output samples that are saturated and adjusts the gain (G) of amplifier 410 in order to keep the power of the samples entering LSB truncation block 230 in a desired target range. The desired target range reduces the number of output samples in Data Out that are saturated to an optimum level.
FIG. 5 illustrates finite impulse response (FIR) filter 135 according to a third exemplary embodiment of the present invention. As in FIGS. 3 and 4 , FIR filter 135 comprises a chain of N−1 sequential delay (D) elements, including exemplary delay (D) elements 201 , 202 , 203 , 204 and 205 . FIR filter 135 also comprises N multipliers, including exemplary multipliers 211 , 212 , 213 , 214 , 215 and 216 . FIR filter 135 further comprises summer 220 , feed-forward calculation block 520 , least significant bit (LSB) truncation block 530 and saturation block 240 . The input stages of FIR filter 135 , up to and including is summer 220 , operate identically to the input stages of FIR filter 200 and need not be discussed in detail again.
The m-bit output of summer 220 is applied directly to the input of LSB truncation block 530 (i.e., without gain amplification). However, unlike the above-described LSB truncation block 230 , LSB truncation block 530 truncates a variable number, k, of least significant bits from the m-bit output of summer 220 . The value of k is determined by feed-forward calculation block 520 . Feed-forward calculation block 520 , discussed below in greater detail, measures the signal strength of the m-bit output of summer 220 and adjusts the value of k in LSB truncation block 530 so that the power of the samples exiting LSB truncation block 530 are in a desired target range.
FIG. 6 illustrates finite impulse response (FIR) filter 135 according to a fourth exemplary embodiment of the present invention. As in FIG. 3-5 , FIR filter 135 comprises a chain of N−1 sequential delay (D) elements, including exemplary delay (D) elements 201 , 202 , 203 , 204 and 205 . FIR filter 135 also comprises N multipliers, including exemplary multipliers 211 , 212 , 213 , 214 , 215 and 216 . FIR filter 135 further comprises summer 220 , feedback calculation block 620 , least significant bit (LSB) truncation block 630 , and saturation block 240 . The input stages of FIR filter 135 , up to and including summer 220 , operate identically to the input stages of FIR filter 200 and need not be discussed in detail again.
The m-bit output of summer 220 is applied directly to the input of LSB truncation block 630 (i.e., without gain amplification). LSB truncation block 630 truncates a variable number, k, of least significant bits from the m-bit output of summer 220 . The value of k is determined by feedback calculation block 620 . Feedback calculation block 620 , discussed below in greater detail, measures the signal strength of the p-bit output saturation block 240 to determine the number of output samples that are saturated and adjusts the value of k in order to keep the power of the samples exiting LSB truncation block 630 in a desired target range. The desired target range reduces the number of output samples in Data Out that are saturated to an optimum level.
FIG. 7A illustrates feed-forward calculation block 520 for adaptively determining the truncation value, k, according to an exemplary embodiment of the present invention. Feed-forward calculation block 520 receives the m-bit outputs of summer 220 and periodically generates values of k. It is noted that feed-forward control block 320 functions in a manner that corresponds to the following description of feed-forward calculation block 520 , except that feed-forward control block 320 generates values of gain, G, that are used by amplifier 310 .
Feed-forward calculation block 520 comprises power estimation block 702 , sum and dump block 704 , filter 706 , and log 2 [X/Threshold1] block 708 . Power estimation block 702 receives the m-bit samples from summer 220 and calculates the power of the samples. Power estimation block 702 may take the absolute value or square value of the signal as the power estimate. Sum and dump block 704 receives the power estimate values from power estimation block 702 , adds consecutive groups of W power estimate values together, divides each sum by W, and outputs the results. In essence, sum and dump block 704 calculates the average value of each group of W consecutive power estimate values received from power estimation block 702 . Thus, the data rate at the output of sum and dump block 704 is 1/W the data rate at the output of power estimation block 702 .
Filter 706 then filters the average values from the output of sum and dump block 704 to reduce noise and jitter. The smoothed and filtered output of filter 706 is then applied to log 2 [X/Threshold1] block 708 . In an exemplary embodiment of the present invention, the value X represents the bit weight of the most significant bit in the output of filter 706 . For example, if the output of filter 706 is 0000010000001000 binary (1032 decimal), the 11 th bit is the most significant bit and X equals 1024. The pre-determined Threshold1 value is set so that the correct number of bits, k, are truncated from the output of filter 1024 for a target power output level.
For example, if Threshold1=64 and X=1024, then [X/Threshold1] equals 16 and the output of log 2 [X/Threshold] block 708 is k=4. If the output of summer 220 is 0001010000001000 binary (5128 decimal) and four bits are truncated from the output of summer 220 , then the input to saturation block 240 is the value 000101000000.
FIG. 7B illustrates feedback calculation block 620 for adaptively determining the truncation value according to an exemplary embodiment of the present invention. Feedback calculation block 620 receives the p-bit outputs from saturation block 240 and periodically generates values of k. It is noted that feedback control block 420 functions in a manner that corresponds to the following description of feedback calculation block 620 , except that feedback control block 420 generates values of gain, G, that are used by amplifier 410 .
Feedback calculation block 620 comprises power estimation block 752 , sum and dump block 754 , adder 756 , filter 758 , decision block 760 , and integration block 762 . Power estimation block 752 receives the p-bit samples from saturation block 240 and calculates the power of the samples. Sum and dump block 754 receives the power estimate values from power estimation block 752 , adds consecutive groups of W power estimate values together, divides each sum by W, and outputs the results. In essence, sum and dump block 754 calculates the average value of each group of W consecutive power estimate values received from power estimation block 752 . Thus, the data rate at the output of sum and dump block 754 is 1/W the data rate at the output of power estimation block 752 .
Next, adder 756 subtracts a pre-determined Threshold2 value from the power average values at the output of sum and dump block 754 . The Threshold2 value in FIG. 7B is different than the Threshold) value in block 708 in FIG. 7A . The output of adder 756 is an error value that may be equal to 0, may be greater or equal to 1, or may be less than or equal to −1. The error value from adder 756 is filtered and smoothed by filter 758 . The output of decision block 760 has only three values: +1, 0, or −1. If the filtered error value is less than +(Threshold3) and greater than −(Threshold3), then the output of decision block 760 is 0. If the filtered error value is equal to +(Threshold3) or greater, then the output of decision block 760 is +1. If the filtered error value is equal to −(Threshold3) or less, then the output of decision block 760 is −1. The Threshold3 value in decision block 760 is different than the Threshold) value in is block 708 and the Threshold2 block in adder 756 . The Threshold3 value is used to further remove jitter in output k. Thus, the output of decision block 760 is a sequence of +1, 0 and −1 values that are integrated by integration block 762 . The output of integration block 762 is the value k.
If the p-bit output power from saturation block 240 are too high (i.e., frequent saturations), then the outputs of sum and dump block 754 are consistently higher than the Threshold value on the input of adder 756 . As a result, the error values from adder 756 are consistently greater than or equal to +1 and the outputs of decision block 760 are mostly +1 values. This causes the output of integration block 762 to rise and the value of k increase. This results in a greater number of least significant bits being truncated from the output of summer 220 and the average power of the p-bit outputs of saturation block 240 decreases. Conversely, if the p-bit output values from saturation block 240 are too low, a smaller number of least significant bits are truncated from the output of summer 220 and the average power of the p-bit outputs of saturation block 240 increases.
In the embodiments illustrated above in FIGS. 3-6 , the input stage of FIR filter 135 (i.e., delay elements 201 - 205 , multipliers 211 - 216 and summer 220 ) is a direct form realization of an FIR filter. However, those skilled in the art will recognize that FIR filter 135 may be embodied as any type of FIR filter, including, for example, a transpose filter realization. Generally speaking, the input stage of any FIR filter receives input samples having a relatively small number of significant bits and generates outputs samples having a relatively large number of bits. Advantageously, adaptive truncation circuitry according to the principles of the present invention may be easily implemented with any type of FIR filter input stage.
Although the present invention has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.
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A fixed point finite impulse response (FIR) filter comprising: 1) an input stage for receiving an input signal as a sequence of input samples comprising: i) delay elements connected in series for receiving and shifting N sequential input samples; ii) multipliers, each multiplier receiving a selected one of the N sequential input samples from the delay elements and multiplying the selected input sample by a corresponding coefficient to produce an intermediate product; and iii) a summer for receiving and adding N intermediate products from the multipliers to produce an output sum signal comprising a sequence of output sum samples; and 2) an output stage for truncating k least significant bits (LSBs) from each of the output sum samples, wherein k is a variable number.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. patent application, Ser. No. 08/778,765, now U.S. Pat. No. 6,004,349, filed Jan. 6, 1997 and entitled, “Set Screw for Use with Osteosynthesis Apparatus”, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to improvements in set screws for use with apparatus for correcting orthopedic deformities and, in particular, for use in spinal osteosynthesis.
Surgically implanted spinal osteosynthesis apparatus often includes rods which are secured along at least a portion of the spine by a system of hooks, bone screws including sacral screws and pedicle screws and transverse connectors for the purpose of stabilizing and adjusting spinal alignment. In a very basic apparatus of this type, the hooks and bone screws include a spinal rod bore extending through a ring or body or head of the hook or screw. The screws are screwed into the pedicle portion of the vertebra at desired locations and a spinal rod is then extended through the spinal rod bore in each bone screw.
Where the bone screw has a rod receiving ring and the rod is to be fixed in position in the ring, a set screw is inserted in a threaded bore extending through a wall of the ring, so as to engage the rod, and is then tightened to fix the translational and rotational relationship of the rod within the ring. The rods may then be bent or shaped to maintain an adjacent portion of the spine in a desired configuration, to provide support to the spine and to exert desired corrective or stabilizing forces on the spine.
A slightly more complicated system uses transverse connectors in association with the bone screws to secure the spinal rods. The transverse connectors include an arm and a head. The head has a spinal rod bore extending therethrough. The arm of the connector is inserted through the spinal rod bore in the pedicle screw then the spinal rod may be inserted through the spinal rod bore in the transverse connectors. A threaded bore extends through the head of the connector perpendicular to the axis of the spinal rod bore. Once the rod is inserted through the bore in the transverse connectors the set screws are inserted through the threaded bores and tightened to fix the relative position of the rod within the spinal rod bore and set screws are inserted in the threaded bores and tightened to fix the position of the transverse connector with respect to the pedicle screws.
The pedicle screws and transverse connectors may be of the closed type as discussed above or of an open end type wherein the head of the screw or connector generally incorporates a U-shaped groove. Several types of open end type bone screws have been previously used. One type of such screw is shown in the U.S. Pat. No. 5,005,562 of Cotrel. The device in the Cotrel patent has threaded interior surfaces on the two upright branches that form the rod receiving channel therebetween and which receive a threaded set screw having a rod engaging point and outer ring. The set screw in Cotrel is tightened against the rod by advancing the set screw along the threads. However, this system has limitations. In particular, the ability of the set screw of Cotrel to grip and hold the rod is heavily dependent on the torque applied to the set screw during installation. Unfortunately, the torque is limited because too much torque will cause the branches to spread, thereby allowing the set screw to loosen and the implant to fail. Such failure can also occur when forces are applied to the implant during use, such as at time of muscular stress or during accidents when the back is jolted. To try to overcome this problem associated with the Cotrel device, the implant branches and set screw are increased in size to add strength and/or a retention ring is placed around the outside of the branches to reduce the likelihood of expansion. However, the strengthening adds substantial bulk to an implant and a ring adds bulk and complexity to the implant. In implants it is important to try to reduce bulk rather than add to it, as it is desirable for the implants to be as low profile as possible.
Rather than have a pair of branches joined only by a set screw or by a set screw and an exterior ring, a cap has been proposed which mates with the branches on opposite sides of the cap to prevent the branches from expanding radially outward upon application of torque to the set screw. The cap also closes off the open end of the bone screw after the rod is placed in the groove in the bone screw. The set screw is then inserted in a threaded bore in the cap and tightened to fix the position of the transverse connector with respect to a respective bone screw. A substantial torque can then be applied to the set screw while held in the surrounding threads of the cap without expanding the bone screw branches.
Various implants such as hooks, pedicle screws and transverse connectors used in the present invention may be of the closed type, as discussed above, or of an open end type, such as described above, wherein the head of the hook screw or connector generally incorporates a U-shaped groove or slot, an upper end of which may be closed off by a cap after a rod is placed in the open end so as to complete the rod bore. A threaded screw bore for the set screw typically extends through the cap.
The efficacy of the set screw is critical to the overall performance and efficiency of the osteosynthesis apparatus. The set screw must firmly secure the spinal rod or the arm of transverse connectors to prevent rotational or translational movement of the rod or arm after installation. Due to the nature of use of the set screw, it is important that the set screw be relatively small yet constructed to receive sufficiently high torque to firmly set the set screw and hold the rod. The set screw must also be easily manipulated to permit relatively rapid insertion and tightening during surgical procedures. It is also preferable that after insertion, no portion of the set screw extends beyond the threaded bore into which the set screw is inserted. The remaining portion of the set screw should be removable to facilitate disassembling of the osteosynthesis apparatus at any time. It is desirable that the set screw take advantage of physical penetration into the rod so as to improve the strength of the connection to resist axial movement of the rod relative to the set screw over that provided only by abutting friction.
Set screws have been previously developed with break-off heads or stems which break off after the set screw is inserted through a threaded bore and tightened to a preselected torque. Preferably, no portion of the set screw that remains after the head or stem breaks off extends above or beyond an outer edge of the threaded bore. However, prior art set screws normally have undesirable burrs that are left after the head breaks off that must be removed, thereby making the procedure more difficult or alternatively such burrs may lead to irritation of the patient, if not removed. Often, after installation, a set screw must be removed to reposition a rod or fix a broken apparatus. Prior art set screws have been difficult to remove after the head or stem is broken off. Consequently, it is desirable to have a set screw that can be comparatively easily removed even without a head.
It is also desirable to have a set screw that has an axially aligned tip that penetrates relatively deeply into a rod for preventing movement along or around the rod of an associated implant once tightened, but also includes structure that helps prevent rocking or translational movement of the set screw relative to the point of penetration. Rocking or movement of the screw relative to the location of penetration weakens the grip provided by the tip in the rod and the prevention of such movement substantially strengthens the juncture of the screw and the rod. The set screw tip, such as a point can only penetrate deeply into the rod if sufficient torque can be applied to the set screw to do so. In general greater torque is available due to greater bulk or due to special construction that allows greater strength without adding bulk. The latter is preferred in implants.
In general, there is still a need for an improved set screw which is quite strong in size, reliable in securing an osteosynthesis apparatus in place without burrs or high profile, is easily removable and is relatively small yet easily manipulable to facilitate its insertion and removal.
SUMMARY OF THE INVENTION
The present invention comprises an improved set screw for use in an osteosynthesis apparatus. The set screw is adapted for use in securing a rod or elongate member in a bore of a ring or head of an implant or within a channel in an open headed implant from translational or rotational motion. The ring or ringlike structure formed by an open head with a closure cap is of the type formed in the head of a hook, the head of a bone screw, the head of a connector secured to the bone screw or other type of implant to which a rod is secured. The rod is of the type including spinal rods or the rod portion of a connector which may be round, square or otherwise shaped in cross-section and which has an elongate axis.
A threaded set screw bore extends generally radially through a wall of the ring or head where the implant has a closed head or through a threaded bore in a cap used in conjunction with an “open” head, so as to normally be aligned such that a central axis of the set screw intersects with the elongate axis of the rod or member receiving bore associated with the ring or head of the closed hook, screw or connector. In some instances the axis of the set screw will be perpendicular to an axis of the rod; but in some use the axis of the set screw, while intersecting with the axis of the rod will be non-perpendicular thereto.
The set screw has a head or stem preferably having a hexagonal external cross-section, and a lower portion having a threaded outer surface. A tip is centrally formed on a lower surface of the set screw so as to be coaxially aligned with the axis of the set screw. A peripheral break notch preferably is formed between the head and the lower threaded portion of the set screw to facilitate breaking and separation of the two portions. A cylindrical bore preferably is formed in the set screw and extends through the head or stem and partially, but not completely, through the lower threaded portion.
The set screw is especially effective in conjunction with open headed implants such as bone screws. The set screw is utilized in conjunction with a cap having opposed slots which mate and lock with opposed slots on respective branches of the implant to prevent spreading or separation of the branches once the cap is in position on the head. The set screw is threadably received in an entirely surrounding bore in the cap so as to stabilize the threaded portion of the set screw while torque is applied to the set screw and as the set screw tip or point drives or penetrates into the rod. In a preferred embodiment the set screw includes a tip and a ring having a sharp lower edge that encircles the point and penetrates into the rod to further stabilize the resulting structure.
In use, after the rod is positioned in the ring or ringlike structure, the set screw is tightened or advanced in the set screw bore by a socket type wrench or other suitable driver such that the tip or point engages and bites or penetrates into the outer surface of the rod, while biasing an opposite side of the rod against a side wall of the ring so as to fix the position of the rod relative to the ring, that is, to prevent translational or rotational movement of the rod relative to the ring. Preferably, further tightening of the set screw causes the head or stem to shear off along the peripheral notch preferably without burrs and at a preselected and desired consistent torque that is sufficiently high to allow for considerable penetration of the tip or point into the rod and such that the axis of the set screw generally intersects the elongate axis of the rod or member.
In the break off head set screw, the cylindrical internal bore in the set screw includes an upper bore section and a lower bore section. The upper bore section generally extends coaxial with the head or stem of the set screw and the lower bore section extends partially through the lower threaded portion of the set screw. The upper bore section is adapted to facilitate removal of the set screw head or stem once it is sheared off.
In the break off head set screw, the set screw is adapted for use with a socket type wrench having a male member or projection extending centrally in the wrench socket that mates with the set screw internal bore. The projection has an outwardly extending biasing element thereon. The projection is sized for insertion into at least the upper bore section when the head or stem of the set screw is positioned in the socket. The biasing element biases against the internal wall of the head defining the upper section of the cylindrical bore to help grip the head. The socket type wrench applies torque to the head until a preselected torque is achieved at which time the notch directs the location or point of breakage and the head breaks from the remainder of the screw without leaving substantial burrs or the like extending above the surface of the ring.
In the break off head set screw, after sufficient torque is applied and the head or stem of the set screw is sheared off, the lower bore section is adapted to receive an easy out type tool to permit removal of the set screw lower threaded portion, if necessary. The lower bore section in some embodiments is of a smaller diameter than the upper bore section. A partial reverse starter thread, of at least one half turn, is in some instances formed inside a section of the internal wall of the bore of the set screw defining the lower bore section near an upper end thereof. The reverse thread facilitates gripping and thus starting the easy out type tool to allow the easy out type tool to be used to remove the lower portion of the screw after the head or stem has been broken off. In certain embodiments the side wall of the set screw is threaded which increases breakoff torque and which in some instances provides sufficient wall thickness for an easyout to obtain purchase in the remaining wall without the starter thread.
As noted above in a particular embodiment of the invention, the set screw is used in conjunction with a cap utilized to close an open ring or body surrounding a rod or other elongate member. Caps of this type have a pair of curved ears or slot followers that slideably are received in slots in opposite sides of branches forming the remainder of the ring at an opening to be filled by the cap. The ears slideably lock with the slots so as to prevent radially outward separation of the branches when torque is applied to the set screw or other forces are applied to the implant.
The cap has a central threaded bore to receive a set screw such that the axis of the set screw is positioned to intersect the longitudinal axis of a rod or other member surrounded by the ring. Normally, the slots and ears are aligned such that the ears of the cap can easily slide into the slots from one side, but are tapered so that the ears are trapped by the slots on the opposite side and effectively form a stop to limit movement or prevent removal of the cap from the remainder of the ring from the opposite side. The cap also has a front edge that may be rotated relatively toward the rod when the cap is pushed such that the ears thereof are as deep as possible into the slots of the remainder of the ring.
When the ears are positioned as deeply as possible in the slots and the set screw is tightened against the rod or member, the set screw tip or point penetrates into the rod and the front edge of the cap also engages and wedges against the surface of the rod. The penetration of the tip and wedging of the edge are partially opposed such that, if forces try to move the rod along the axis thereof relative to the ring after the set screw is tightened in a first direction, then such movement is opposed especially by the tip of the set screw, and if forces try to move the rod in the opposite direction such movement is opposed especially by the edge of the cap wedging more tightly and then biting into the surface of the rod.
In a second embodiment a ring having a lower sharp edge encircles the axial point of the screw and penetrates into the rod during use to help prevent movement of the set screw relative to the rod and to thereby help stabilize a set screw that is aligned perpendicularly relative to the major axis of the rod.
OBJECTS AND ADVANTAGES OF THE INVENTION
The objects and advantages of the invention include: providing a locking mechanism with set screw for use in an osteosynthesis apparatus for securing a rod or elongate member from rotational and translational movement within a bore of a securement ring or body; providing such a set screw which is relatively small, yet which can be readily manipulated; providing such a set screw which includes a head or stem which breaks off during tightening at a preselected torque after the set screw has been tightened down; to provide such a set screw which includes a peripheral break inducing and directing notch on an outer surface of the screw between the head or stem of the screw and a lower threaded portion thereof; to provide such a set screw which includes a tip or point for biting or penetrating into the rod to be secured by the set screw; to provide such a set screw incorporating means for facilitating removal of the head of the set screw after it has been broken off; to provide such a set screw which incorporates means for facilitating removal of the lower threaded portion of the set screw when desired; to provide such a set screw having a cylindrical bore extending partially therethrough; to provide such a set screw having an upper bore section extending through the head or stem of the set screw and a lower bore section extending partially through the lower threaded portion of the set screw; to provide such a set screw to be used in cooperation with a cap for completing a ring such that the cap prevents separation of opposite branches of an implant forming a portion of the ring; to provide such a set screw and cap combination wherein the point of the set screw penetrates into the rod and especially resists movement of the rod relative to the ring in a first direction and wherein the cap is rotated to have an edge that is urged to wedge and in some instances to bite into the rod under load by tightening the set screw such that the edge resists movement of the rod relative to the ring in a second direction; to provide such a set screw having a ring with a lower sharpened edge encircling an axially aligned point of the set screw and which during usage penetrates the surface of the rod that is also penetrated by the point so as to stabilize and help prevent movement of the screw relative to the rod once the screw is tightened; and to provide such a set screw which is relatively simple to manufacture and particularly well suited for its intended uses thereof.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction 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 set screw in accordance with the present invention.
FIG. 2 is a front elevational view of the set screw of the present invention;
FIG. 3 is a cross-sectional view, of the set screw, taken along line 3 — 3 of FIG. 2 .
FIG. 4 is a cross sectional view of the set screw, taken generally along line 4 — 4 of FIG. 3 .
FIG. 5 is a front elevational view on a reduced scale of the set screw showing a lower threaded portion of the set screw engaging a spinal rod secured within a spinal rod bore in a bone screw and showing a head or stem of the set screw after being broken off.
FIG. 6 is a side elevational view on a reduced scale of a bone screw secured within a vertebra and with portions broken away to show a lower threaded portion of the set screw of the present invention secured within the bone screw.
FIG. 7 is a fragmentary front elevational view of the set screw shown secured within a socket wrench with portions broken away to show detail.
FIG. 8 is a bottom plan view of the socket wrench, as shown in FIG. 7, without a set screw secured therein.
FIG. 9 is a front elevational view similar to FIG. 5 showing use of an easy out type tool to remove a lower threaded portion of the set screw of the present invention from a bone screw.
FIG. 10 is a fragmentary side elevational view of the set screw utilized in conjunction with an open ring hook and a cap for the hook showing a ring of the hook completed by the cap and the hook secured to a rod.
FIG. 11 is a fragmentary cross-sectional view of the set screw, hook and cap, taken along line 11 — 11 of FIG. 10 .
FIG. 12 is a fragmentary cross-sectional view of the screw, hook and cap, taken along line 12 — 12 of FIG. 10 .
FIG. 13 is a fragmentary side elevational view of the set screw, hook and cap, showing the cap complete but with a portion of the ring broken away to illustrate details.
FIG. 14 is a fragmentary side elevational view of the set screw, hook and cap, showing portions of the ring and cap broken away to illustrate position of the set screw and cap engaging the rod after the set screw is tightened to a torque just prior to a head of the set screw breaking therefrom.
FIG. 15 is a side elevational view of a modified set screw in accordance with the present invention.
FIG. 16 is a cross-sectional view of the modified set screw, taken along line 16 — 16 of FIG. 15 .
FIG. 17 is a bottom plan view of the modified set screw.
FIG. 18 is a side elevational view of the modified set screw partially securing a rod in an implant extension with portions broken away to show detail thereof.
FIG. 19 is a cross-sectional view of the modified set screw and extension, showing internal detail of the set screw prior to removal of a head thereof.
FIG. 20 is a front elevational view of the modified set screw and extension after removal of the head of the set screw with portions broken away to show detail thereof.
DETAILED DESCRIPTION OF THE INVENTION
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.
Referring to the drawings in more detail, the reference numeral 1 generally refers to a set screw for use in osteosynthesis apparatus and in particular for use in spinal osteosynthesis apparatus 2 . As shown in FIGS. 5 and 6, the set screw 1 is adapted for use in securing a rod 5 of the apparatus 2 relative to a rod receiving bore 6 of a head or ring 7 , from translational or rotational motion. The ring 7 is of the type formed in the head of a bone screw 10 or the head of a connector or bone hook (not shown) secured to the bone screw 10 . In the field of spinal osteosynthesis, the bone screws 10 are often referred to as sacral screws or pedicle screws. The rod 5 may be of the type including spinal rods or the arm or rod portion of a connector. The illustrated rod 5 is round; however, it is foreseen that the rod could be square to help prevent rotation in a similarly shaped bore in the bone screw 10 , or have a cross section of almost any shape. A threaded set screw receiving bore 11 extends through the ring 7 perpendicular to the axis of the rod receiving bore 6 and extends radially relative to the ring 7 for the closed hooks, screws and connectors. For open hooks, screws and connectors the angle of point of penetration on the rod may vary with respect to the axis of the rod and to the design for a closing cap thereof.
The set screw 1 , as is shown in FIGS. 1 through 4, comprises a head or stem 20 , of hexagonal external cross-section and round internal cross section, and a lower portion 22 , having a threaded outer circumferential surface 23 . The head 20 is relatively elongated to facilitate manipulation of the set screw 1 . A tip, illustrated as a point 28 , is formed on a lower surface 29 of the set screw 1 centrally thereof so as to extend outward along a central axis of rotation of the set screw 1 . The point 28 forms a point receiving notch, depression, or indentation 30 in the rod 5 . A peripheral break inducing notch 32 is formed between the head 20 and the lower threaded portion 22 of the set screw 1 on an outer surface 33 of the set screw 1 . The notch is positioned and sized to initiate breakage along the radially innermost portion thereof at this level and at a preselected torque without forming substantial burrs on the resulting upper surface of the set screw lower portion 22 .
As best seen in FIG. 3, a cylindrical bore or projection receiving bore 35 , comprising an upper bore section 36 and a lower bore section 37 is formed in the set screw 1 and extends through the head 20 and partially through the set screw lower threaded portion 22 . The upper bore section 36 generally extends coaxial with the head 20 of the screw 1 and the lower bore section 37 extends partially through the lower threaded portion 22 of the screw 1 . The lower bore section 37 is of slightly smaller diameter than the upper bore section 36 . A reverse thread 40 , of preferably at least one half turn, is formed along an internal wall 41 of the set screw 1 defining the lower bore section 37 near an upper end 42 thereof, see FIG. 3 .
A drive slot 46 is located at a top end 47 of the set screw head 20 . The slot 46 is a rectangular notch extending downward in FIG. 3 from the top end 47 with portions on diagonally opposite sides of the screw 1 . The set screw 1 is preferably driven by a hexagonal socket type wrench 49 , partially shown in FIG. 7 . The slot 46 can receive mating parts of the wrench 49 ; however, the drive slot 46 is adapted to also receive a set screw holder type tool for starting the set screw 1 into the threaded set screw bore 11 in some applications.
In use, the set screw 1 may be inserted in the set screw receiving bore 11 in the ring 7 after the bone screw 10 is inserted into a bone 50 of a patient and after a rod 5 is inserted through the rod receiving bore 6 . To secure the rod 5 in position, thereby preventing further rotational or translational movement of the rod 5 with respect to the rod receiving bore 6 , the set screw 1 is further driven through the set screw receiving bore 11 until the point 28 engages and bites into the rod 5 at depression 30 . Further driving or tightening of the set screw 1 produces a preselected torque on the head 20 and causes the head 20 of the set screw 1 to shear off along the radially innermost portion of the peripheral notch 32 , as shown in FIG. 5 . The bore 11 and the penetration of the point 28 into the depression 30 stabilizes the set screw 1 relative to the rod 5 , so that the set screw 1 is able to secure the rod 5 and prevent relative movement of the rod 5 with respect to the bone screw 10 even under substantial load.
The lower threaded portion 22 of the set screw 1 is preferably sized such that after the head 20 is sheared off, an upper surface 55 of the set screw lower portion 22 is generally flush with an upper edge or upper surface 57 of the ring 7 such that no portion of the set screw lower portion 22 extends beyond the upper surface 57 of the ring 7 . Further, after the head 20 is sheared off, the upper surface 55 of the set screw lower portion 22 is generally free from burrs or jagged edges.
The set screw 1 may also be pre-loaded into the bone screw 10 , or related structure, prior to insertion into the patient. In particular, the set screw 1 may be manually inserted in the threaded set screw receiving bore 11 of a bone screw 20 or a connector before insertion in a patient and rotated a sufficient number of turns such that the set screw 1 is secured in the set screw receiving bore 11 , but such that the point 28 does not extend substantially into the rod receiving bore 6 . The bone screw 10 , with the set screw 1 secured thereto, may then be secured into the appropriate bone 50 of a patient. After a rod 5 is inserted through the rod receiving bore 6 of the bone screw 10 . Thereafter, the set screw 1 is tightened, as discussed above.
The upper bore section 36 of the set screw 1 is adapted to facilitate removal of the set screw head 20 once it is sheared off from the lower threaded portion 22 . The set screw is adapted for use with the socket type torque wrench 49 , as shown in FIGS. 7 and 8, having a hexagonal socket 64 and a male member or projection 65 extending centrally in the socket. The projection 65 includes a resilient biasing member 66 circumferentially secured thereon. The projection 65 is sized for insertion into at least the upper bore section 36 when the set screw head 20 is positioned in the socket 64 . The resilient biasing member 66 biases against an internal wall 70 of the head 20 defining the upper bore section 36 to grip the head 20 .
The internal wall 70 has a chamfer 71 at the top end 47 of the set screw head 20 to facilitate insertion of the projection 65 into the projection receiving bore 35 in part by facilitating compression of the resilient biasing member 66 . The resilient biasing member 66 , as shown in FIGS. 7 and 8, generally comprises a split washer type spring, however it is foreseen that the biasing element 66 may be of a wide range of configurations and structures. Further other retention means for releasably securing the set screw 1 to the projection 65 may be utilized including a rubber washer, magnetic coupling means, and various structure producing an interference fit between the projection 65 and the projection receiving bore 35 .
The projection 65 may include a pair of drive projections or tabs 74 extending laterally from opposite sides of the projection 65 and adapted to mate with the drive slot 46 extending across the top end 47 of the set screw head 20 to permit an installing surgeon to drive or rotate the set screw 1 by the projection 65 .
After the head 20 has been sheared off from the set screw lower threaded portion 22 , the lower bore section 37 is adapted to receive an easy out type tool 75 to permit removal of the set screw lower portion 22 when necessary and as is shown in FIG. 9 . The reverse thread 40 facilitates starting the easy out type tool 75 by allowing the tool 75 to get an initial grasp after which it would be expected to cut further into the lower bore 37 .
The bone screws 10 and related connectors (not shown) discussed above are of a closed end variety in that the ring 7 is of one piece construction. The set screws 1 of the present invention are also adapted for use with bone screws and connectors of the open end variety (not shown). In the open end variety, the ring 7 includes a generally U-shaped groove opening along an upper end of the head or ring 7 . A saddle or cap is securable to the head 7 to close off the groove and form the rod receiving bore 6 . The set screw receiving bore 11 may be formed in the cap or another part of the head 7 .
Shown in FIGS. 10 through 14 is a modified embodiment of apparatus of the invention utilizing the set screw 1 described above.
In particular, FIGS. 10 through 14 show an elongate implant first member, here a rod 100 having a central elongate axis designated by the reference numeral A. The screw 1 is as described above and has a central axis B. The axes A and B intersect subsequent to assembly, as is shown in FIGS. 10 through 14, although at an angle that is not a right angle.
The set screw 1 is utilized in conjunction with a second member, here an implant hook 102 , having a hook body or head 103 and a hook finger portion 104 . The head 103 is somewhat U-shaped forming a central partial bore 105 surrounded by a partial ring 106 . When the apparatus is assembled, the rod 100 is cradled by the bore 105 and the partial ring 106 .
On opposite sides of the facing ends of the partial ring are curved or U-shaped slots 108 and 109 . The slots 108 and 109 are not parallel but slightly converge to the left in the view seen in FIG. 10 .
A cap 115 is located so as to complete the ring initiated by the partial ring 106 . The cap 115 has a pair of slot followers or ears 116 and 117 that are sized and shaped to be received in the slots 108 and 109 respectively. The ears 116 and 117 are parallel and do not converge and are curved to conform to the curve of the slots 108 and 109 . The lower ends 119 and 120 of each side of the cap 115 are curved and are received by simultaneously curved shoulders 122 and 123 on opposite sides with the partial ring 106 . The cap 115 is united with the partial ring 106 by inserting the ears 116 and 117 of the cap 115 into the slots 108 and 109 of the partial ring 106 from the right side as seen in FIG. 10 . The cap 115 is then partially rotated to the left (again as viewed in FIG. 10) by allowing the cap lower ends 119 and 120 to slide on the shoulders 122 and 123 respectively until the convergence of the slots 116 and 117 binds with the ears 108 and 109 so as to limit further relative movement of the cap to the left in FIG. 10 and operably function as a stop. This bound position is seen in FIGS. 10 through 14. It is foreseen that a stop can be provided by other structure and function within the concept of the invention. When the cap 115 is located so as to complete the partial ring 106 , the cap 115 prevents lateral separation of opposite branches forming the partial ring 106 when torque or lateral forces are applied thereto.
The cap 115 has a rear edge 130 and a front edge 131 . When the cap 115 is in or near the bound position, the front edge 131 engages and partially penetrates into the rod 100 , as is seen in FIG. 14, as the set screw 1 is tightened. This penetration forms a notch 135 into the rod 100 .
The cap 115 has a centrally located threaded bore 137 that receives the threaded lower portion 22 of the set screw 1 , as is seen in FIGS. 10 through 14.
As the set screw 1 is advanced in the cap bore 132 the set screw tip or point 28 advances toward and eventually engages the rod 100 . The set screw 1 is torqued until the point 28 penetrates the rod 100 so as to produce a point receiving depression or notch 139 in the rod 100 . In this manner both the point 28 and the cap front edge 130 penetrate the rod 100 . The set screw 1 also biases the rod 100 against a side wall 140 of the partial ring 106 . The surrounding nature of the cap bore 132 relative to the set screw 1 , as seen in FIG. 14, in conjunction with the penetration of the point 28 into the rod 100 and the engagement of the cap edge 131 with the rod 100 forms a very stable configuration that substantially resists movement of the rod 100 relative to the implant hook 102 even when substantial forces are applied through use or accident to cause relative movement.
As seen in FIG. 14, if forces urge the rod 100 to the left relative to the partial ring 106 , then the cap front edge 130 especially resists relative movement, and if forces urge the rod 100 to the right relative to the partial ring 106 , then the set screw point 28 especially resists relative movement. As has been discussed before the upper portion 20 of the set screw is subsequently removed by application of additional rotational force thereto until a preselected torque is achieved. In this manner the hook 102 is securely held to the rod 100 with relative good stability.
Shown in FIGS. 15 through 20 is a modified embodiment of a set screw in accordance with the present invention and generally represented by the reference numeral 200 . The set screw 200 is shown in use with an implant extension 201 to secure a rod 202 in the extension 201 .
The parts of the set screw 200 are in many ways quite similar to the parts of the set screw 1 except for size of parts relative to each other and except as noted below. Consequently, the set screw 200 will not be described in detail, but rather reference is made to the description of set screw 1 for detail not described here. The set screw 200 includes a head 205 with a central and axial bore 206 , a lower portion 207 with an exterior thread 208 and a lower axially aligned point 209 .
The main difference between the screw 1 and the screw 200 is the inclusion of a ring 215 positioned to encircle the point 209 . The ring 215 extends 360 degrees around and is radially spaced from the point 209 . A lower edge 216 of the ring 215 is sharpened and adapted to cut into the rod 202 when urged thereagainst. The point 209 preferably extends axially outward and downward further than the ring 215 so as to penetrate deeper into the rod 202 during use.
The illustrated extension 201 is a conventional extension having an elongate rod shaped member 220 fixedly attached to a ring member 221 having a central bore 222 . The bore 222 is aligned perpendicularly with respect to a major axis of the rod shaped member 220 .
The ring member 220 is two piece and includes a V-shaped portion 224 with a pair of arms or branches 225 and 226 aligned on opposite sides of the bore 222 and a closure cap 227 . The cap 227 has a threaded bore 228 adapted to threadably receive the set screw 200 , as seen in FIGS. 18 to 20 .
The branches 225 and 226 each include facing and inwardly directed flange like structures 235 which form slots 236 . Opposite sides of the cap 227 include slot followers 237 which are slideably received in respective slots 236 when the set screw 200 is in a non tightened state. The slot followers 237 are shown in the slots 236 in FIGS. 18, 19 and 20 .
In use the set screw 200 is threaded into the receiving bore 223 , such that the point 209 engages a rod 202 received in a bore 222 of the ring member 221 . As the set screw 200 is tightened the point 209 penetrates the rod 202 and forms an indentation 230 in the rod 202 , see FIG. 19 . Preferably, the point 209 penetrates substantially into the rod 206 . As the point 209 continues to penetrate the rod 206 , the edge 216 of the ring 215 engages and then also penetrates the rod 202 so as to form a groove 231 , although preferably not as deeply as the point 209 . Torque is then further applied to the set screw 200 until a desired predetermined torque is applied to the set screw 200 at which time the head 205 breaks from the remainder of the screw 200 leaving the lower body 207 in the bore 228 and the point 209 penetrated into the rod 202 . The ring 215 also partially penetrates into the rod 202 .
When the set screw 200 is fully tightened, the cap 227 is biased away from the rod 202 . This causes the slot followers 237 to snugly and tightly fit against the respective slots 236 into which they are received. This in turn secures and locks the cap 227 in position to complete a ring with the V-shaped portion 224 . This also secures the branches 225 and 226 so as to prevent the branches from separating radially outward from each other so as to loosen the set screw 200 or the connection of the rod 202 to the connector 201 when stress is placed upon the implant due to strain or accident as well as when torque is applied to the set screw 200 during installation. The combination of the cap bore 228 holding the set screw acting in conjunction with the point penetration into the rod 202 by the point 209 and the penetration of the ring 215 into the rod 202 at least at two axially spaced locations on the rod 202 on opposite sides of the point 209 , substantially stabilizes the set screw 200 relative to the rod 202 and greatly resist axial or rotational movement of rod 202 relative to the connector 201 once the set screw 200 has been fully torqued, as in FIG. 20 .
The set screw body 207 can be removed from the bore 223 in the manner described for removing the set screw lower portion 22 from the position shown in FIG. 5 .
It is foreseen that while a hook and connector have been described and illustrated in certain embodiments of the invention in conjunction with a cap, that the apparatus and method of joining an open ring that is completed with a cap with an elongate member such as a round rod, can be utilized with other devices using similar structure such as bone screws or connectors and that a first member having a non-round cross-section, such as a square cross-section, could be used.
It is noted that while the set screws of the present invention may be used in conjunction with knurled rod, knurlling causes the rod to be weakened and fail more easily. Therefore, it is normally preferable to use the set screws of the invention with smooth surface rod. The set screws of the present invention are especially effective in penetrating into and preventing relative motion between the set screw and smooth rod. In addition the set screws of the present invention can be applied with a relatively high torque because the bore in which the set screw is received is closed and completely surrounds the set screw so that it does not spread during torquing and such that the set screws of the present invention can relatively deeply penetrate into rod, especially smooth rod, and hold securely against relative movement while stabilizing the screw with respect to the rod, even when the screw is positioned in the closure cap of an open ended implant. The set screws of the present invention may also be relatively small, for example 5.5 mm. in diameter, and still provide a strong and stable positional stabilization of an associated implant relative to a rod received in the implant.
It is further noted that the stabilization system of the present invention may in some instances utilize a ring with a lower cutting edge to penetrate into a rod on diagonally opposed locations relative to the ring without including a point. Consequently, the set screw may have a tip that has a point and/or has a ring that in each case penetrates into the rod and that functions with the bore that surrounds the set screw to stabilize the structure.
It is also foreseen that in some specialized uses of the set screw that the set screw will be configured to incorporate a stabilizing structure, but that the head will not be removable, that is, broken from the remainder of the set screw upon application of torque. In such instances the head will normally be solid without an interior bore, but such a head could also include an interior bore for receiving a tool for guidance or control during installation.
It is to be understood that while certain forms 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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An improved set screw with a break off head for use in an osteosynthesis apparatus. The set screw comprising a head or stem preferably having a hexagonal external cross-section, a lower portion having a thread extending around an outer surface thereof and a shank connecting the head to the threaded lower portion. An outer diameter of the shank is equal to a minor diameter of the threaded lower portion, i.e. the outer diameter of the threaded lower portion at the base of the thread. A bore extends into the set screw from an upper surface thereof. The bore has a first bore section and a second bore section wherein the second bore section has a reduced diameter relative to the first bore section and is separated from the first bore section by an internal shoulder. The internal shoulder extends into the bore below an upper end of the thread. The first bore section is sized relative to the shank to result in shearing of the head from the lower portion upon application of a pre-selected torque on the head relative to the lower portion. The stepped down bore configuration also facilitates use of an easy out tool for removing the threaded lower portion, if necessary, from an implant in which it has been secured. The bore may include a plurality of bore sections of increasingly smaller diameter to further facilitate use of an easy out tool.
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BACKGROUND AND FIELD OF THE INVENTION
Jack-ups have been used for oil or gas well drilling, work platforms, oil or gas production platforms, and many other uses. These jack-ups usually consist of a barge shaped hull, generally triangular in plan, supported by three or more trussed legs which usually extend vertically through openings in the hull at the “corners” of the triangle, or extremities of the hull. The trussed legs are usually fitted with vertically extending toothed gear racks on the chords of the legs and the hull is usually fitted with elevating gear units, commonly referred to as “jacks”, that engage with the gear racks to raise and lower the legs when the jack-up is afloat and to raise and lower the hull when the legs have penetrated the ocean floor.
For normal operations, when putting a jack-up on an operating location, the legs are lowered to the ocean floor with the jacks, and jacking continues until soil resistance to penetration of the legs causes the hull to lift out of the water a few feet. Additional soil resistance is usually developed to simulate the largest reaction between the legs and the ocean floor that may be anticipated while at that location. This is normally done by pumping sea water into ballast compartments of the hull.
After developing this additional soil resistance, the hull is then elevated to the desired elevation, which is at least high enough to assure that the crest of the largest anticipated waves will be below the bottom of the hull.
While elevated in this operating position, jack-ups may be subjected to large forces from storm winds, waves and currents. These forces induce stresses in the hull and trussed leg members. Resistance to these storm induced stresses normally determines the strength requirements for the design of the leg members. Additionally, resistance to these storm forces usually determines the maximum leg footing reaction to the ocean floor, therefore it also determines the preload tank capacity requirements. These forces induce large interacting forces and moments between the hull and the legs of jack-ups. For jack-ups without leg-to-hull locking systems, resisting these interacting forces may control the design of the leg guide support structure and portions of the elevating gear units. For jack-ups with leg-to-hull locking systems, resisting these interacting forces usually controls the design of the leg-to-hull locking systems and their support structure on the hull.
The elevating gear units of a jack-up, commonly referred to as “jacks”, are usually mounted in housings that are located radially out from the center of each leg chord and extend vertically up from a location above the top deck of the hull. The gear units are normally mounted one above the other in the housings. Usually there are two levels of leg guides which keep the legs relatively perpendicular to the hull bottom. With this arrangement, the jacks resist all vertical interaction forces between the hull and the legs, and the jacks work together with the leg guides to resist the storm induced moment between the hull and the legs. Some jack-ups have hull-to-leg locking systems, commonly referred to as “rack chocks”, that are installed after the jack-up is elevated to the operating position. These locking systems are used to support the hull on the legs and resist the interacting forces between the hull and legs that are caused by the environmental forces.
U.S. Pat. No. 5,906,457, issued to the applicant, is illustrative.
Recently the exploration and production in deeper water locations has become increasingly important. Available existing jack-ups are often not suited to deeper water, or more sever conditions, or the combination of water depth and environmental criteria of the desired location. The large loads from storm winds, waves and currents, combined with longer leg lengths cause studies for using existing jack-ups to show that one or more of the above limiting design parameters is exceeded. The prior art solution has been to use floating rigs at greater cost.
U.S. Pat. No. 4,378,178 to Roach relates to a lightweight offshore platform structure for use at a plurality of successive sites which is adjustable in height to accommodate a range of water depths. A plurality of anchors spaced around the structure and attached to the ocean floor comprise an anchoring means and are joined to the structure via lower and upper guylines. The attachment of the lower guylines occurs below the water surface sufficiently deep so as to avoid interfering with boats and the like, whereas the upper guylines are adjustable attached the platform to stabilize the structure against storm conditions.
U.S. Pat. No. 3,515,084 to Holmes discloses a floatation unit which may be added to a conventional mat jack-up type platform to permit use of the drill platform in both shallow and deep water drilling operations. As shown in FIG. 2 , the entire apparatus is anchored to the seabed by a plurality of mooring lines, symmetrically arranged about the platform.
U.S. Pat. No. 4,797,033 to Polack shows an anchor line-stabilized system for an articulated tower system including at least three chain devices or lines having upper ends coupled to an upper portion of the tower and lower ends anchored to the sea at locations spaced about the tower. Inclinometer means are utilized to sense tilting of the tower and to operate winch means that pull on at least one chain device extending largely opposite to the direction of tilting.
U.S. Pat. No. 4,818,146 to Fontenot provides a stabilizer for an offshore wellhead and conductor comprising an annular braced secured to the conductor, the brace including a plurality of pulleys symmetrically disposed around the brace below the surface of the water. A plurality of cables is each secured at a first end of the cable to the brace, and each of the cables is journaled around one pulley and extends outwardly and downwardly from the pulleys of the brace down to the mudline. The cable is secured at its second end to an anchor pile beneath the mudline for holding the cables in a fixed position. Similar systems incorporating an annular brace as well as a plurality of anchoring cables are shown in U.S. Pat. Nos. 4,710,061 and 4,640,647 both to Blair et al. A related system of anchoring cables but lacking an annular brace is shown in U.S. Pat. No. 5,061,131 to Petty et al.
U.S. Pat. Nos. 5,906,457, 4,378,178 to Roach, U.S. Pat. No. 3,515,084 to Holmes, U.S. Pat. No. 4,797,033 to Polack, U.S. Pat. No. 4,818,146 to Fontenot, U.S. Pat. No. 4,710,061 and U.S. Pat. No. 4,640,647 both to Blair et al., and U.S. Pat. No. 5,061,131 to Petty et al. are all hereby incorporated by reference. The prior art does not provide a solution for increasing the service life, deeper water capability, or more severe environmental capacity for existing jack-up rigs.
SUMMARY OF THE INVENTION
The present invention enables existing jack-ups to be used in deeper water locations, or in locations where the storm forces are more severe than before. This invention relates to an arrangement whereby a taut mooring system is installed on a self-elevating mobile offshore platform, commonly referred to as a “jack-up”, after the hull has been elevated to an operating position above the highest anticipated wave crests. In this elevated position the hull of the jack-up is supported by trussed legs which extend vertically through openings in the hull to the ocean floor. Common jack-ups are generally triangular in plan, with a leg at each “corner” of the triangle, or each extremity of the hull. The invention extends to other configurations. The taut mooring system consists of: mooring line connections that are radially spaced in plan on the extremities or corners of the platform structure; suction pile anchors that are radially spaced around the jack-up, consistent with the radial spacing of the connection means; taut mooring lines that are radially attached between the suction piles and the connections, and a tensioning system for the mooring lines. The invention may also utilize reinforcements at the mooring line connection locations.
The present invention provides a taut mooring system that will consist of suction pile anchors, spaced radially around a jack-up, that are connected with taut mooring lines to radially spaced connections on the jack-up, that has been elevated above the sea water surface with its legs extended to the ocean floor, thereby enhancing its storm survival capabilities.
The present invention provides a taut mooring system on a jack-up that will provide resistance to some of the forces that may be applied to the jack-up by combinations of wind, wave and current, thereby increasing the severity of the environmental criteria that the jack-up is capable of resisting.
The present invention provides a taut mooring system on a jack-up, that has been elevated above the sea water surface with its legs extend to the ocean floor whereby the attached taut mooring system reduces the natural period of lateral motion of the jack-up so that the dynamic response to waves will be reduced. The reduced dynamic response will increase the environmental criteria that the jack-up is capable of resisting.
The fatigue lives of new jack-up designs will be increased by incorporating the use of a taut mooring system in the design. The taut mooring systems will reduce the natural period of lateral motions, which reduces the wave size that is likely to produce synchronous motions, resulting in fewer and lower levels of cyclic stresses which are likely to cause fatigue cracks in the critical structure of the jack-up.
The service lives of some existing jack-ups will be extended by incorporating the use of taut mooring systems to extend their fatigue lives when estimates show that the remaining fatigue lives are less than their estimated useful lives.
The safe working area of operation for existing jack-ups may be expanded by deploying a taut mooring system when it is desired to operate in areas where the anticipated magnitude of the environmental forces exceed the existing capability of the jack-up, in the unmoored condition.
The maximum operating water depth limit of existing jack-ups may be increased by the combination of lengthening the jack-ups legs and deploying a taut mooring system, when in these deeper waters. The taut mooring system will resist environmental forces to compensate for the moment increasing effects of the increased water depth. It will also reduce the natural period of harmonic motion for lateral deflections, which will compensate for the increased natural period of the unmoored jack-up, due to the increased water depth.
Incorporating the use of taut mooring systems on new jack-up designs for some of the intended areas of operation, can expand the design capabilities versus cost and increase its marketability.
New jack-ups can be designed and constructed with adequate structural strength in the hull of the jack-up to allow for the attachment of a more robust taut mooring system than may be practical as a modification to an existing jack-up. The result will be designs that are more efficient in cost versus performance than is possible with a retro-fit taut mooring system.
In embodiments of the present invention, the jack-up's elevating system can be used to tighten the mooring lines of the taut mooring system. This eliminates the need for tightening apparatus such as chain ratchets to be provided or installed. In applications where additional jacking units are provided for tensioning the taut mooring lines, the jacking units will allow for individual tautness adjustment without the need for jacking the platform on the legs. Additionally, the invention can provide a connecting means such as pin connections between the mooring jacking units and the jack-up platform so that the additional jacking capacity can be utilized to increase the variable loads when elevating the platform above the sea surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : is a schematic elevation view of one form of jack-up with trussed legs and taut mooring lines connected to the hull of the jack-up.
FIG. 2 : is a schematic plan view of the jack-up of FIG. 1 .
FIG. 3 : is a schematic elevation view of another form of jack-up with trussed legs that are triangular in plan and taut mooring lines connected to additional jacking units.
FIG. 4 : is a schematic plan view of the jack-up of FIG. 3 .
FIG. 5 : is a schematic elevation view of another form of jack-up with trussed legs that are square in plan with taut mooring lines connected to additional jacking units.
FIG. 6 : is a schematic plan view of the jack-up of FIG. 5 .
FIG. 7 : is a plan view detail of the mooring line connection for a triangular leg jack-up.
FIG. 8 : is an elevational view detail of the mooring line connection and auxiliary tensioning jack unit for a triangular leg jack-up.
FIG. 9 : is a plan view detail of the mooring line connection for a square leg jack-up.
FIG. 10 : is an elevational view detail of the mooring line connection and auxiliary tensioning jack unit for a square leg jack-up.
FIG. 11 : is an elevation of a mooring padeye connection detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the foregoing drawings, in which like parts are given like reference numerals.
FIGS. 1 and 2 illustrate, in elevation and plan respectively, one type of a self elevating mobile offshore jack-up platform 1 . The platform is provided with trussed legs 2 which extend through openings 3 in the hull 4 of the jack-up rig located at the corners or extremities of the hull. Openings 3 are further provided with upper leg guides and lower leg guides Each leg 2 is provided with a mechanism or mechanisms 5 for “jacking” or for moving the leg vertically with respect to the hull of the platform. These mechanisms 5 are commonly pinion gear drives mounted to the hull working in combination with one or more gear racks fixed to each leg 2 . A typical arrangement will have each leg 2 provided with one gear rack and a pinion gear drive at each corner or chord of the trussed leg. The gear racks are fixed to or formed as part of the leg chords. Trussed legs are typically either triangular in plan ( FIGS. 2 and 4 ) or square in plan (FIG. 6 ).
The taut mooring system of the present invention consists of: mooring line connections 6 that are radially spaced in plan on the corners or extremities of the hull 4 ; anchors 7 that are radially spaced about the jack-up, consistent with the radially spacing of the connections; taut mooring lines 8 that are radially attached between the anchors 7 and the connections 6 , and a tensioning system 9 for the mooring lines. See FIGS. 1 through 6 .
Anchors 7 can be submerged plates, driven piles or plates, or in the primary embodiment envisioned, suction piles. Mooring lines can be cables, and/or chains, either of steel, alloy or composites. In the primary embodiment envisioned the mooring lines would be Kevlar cables.
Multiple cables or single cable configurations at each leg are considered equally appropriate. Symmetry of the cable orientation is desired. As shown in FIGS. 3 and 4 , of the triangular leg jack-up, the mooring lines 8 extend radially from the leg corner 10 , and radially from the center point of the hull 11 and radially from the center point of the leg. In contrast, as shown in FIGS. 5 and 6 for square leg designs, the mooring lines 8 extend from the leg corner 10 at an angle from a line through the leg center and the leg corner 10 so that the cable or mooring line directions are all also radially extending from the center point of the hull 11 .
The present invention utilizes mooring lines 8 angled from the horizontal. FIGS. 1 , 3 , and 5 . The angle reduces line length in comparison to conventional non-taut mooring systems commonly used on floating structures and vessels. It is desirable for the mooring line 8 to be both short and taut, if forces are to be induced into the mooring lines by storm induced lateral deflections. Long lines with significant slack absorb little force as the jack-up deflects laterally when storm forces are applied to it. Lines that are angled too steeply from the horizontal induce the higher axial load on the legs. Where lines are longer the materials and cross sections of the lines might need to be made larger in order to maintain the desired spring stiffness. Cable angles steeper than the 45 degrees ( 12 at FIG. 1 ) would induce high axial load upon the jack-up legs. Cable angles that are numerically smaller such as 20 degrees might be used. The optimum angle based upon current analysis would be 30 degrees from the horizontal. FIGS. 3 and 5 , 13 .
Conventional anchors work effectively when the pulling force of the mooring lines is nearly horizontal. However, the anchors can be easily pulled loose if there is a significant upwards vertical component of the line pull. The anchor system envisioned in the present invention in its primary embodiment would use suction piles 14 . See FIGS. 1 , 3 and 5 . Suction piles are cylindrical caissons that are installed by pumping water out of the caisson, which creates a suction force that pushes the caisson into the soil. Suction piles are removed by pumping water into the caissons, which creates an expansion force that pulls them out of the soil. Suction piles are used as anchors with this invention because they have the ability to resist large vertically upward forces and because they are not only easy to install, but are also easy to remove. As a result, the same suction piles can be reused on multiple locations or alternatively, they may be rented if needed for a particular location.
When it is proposed to use a particular jack-up for operations on a specific location, a study is usually made to determine if any of the limiting design parameters will be exceeded. Some of the usual limiting design parameters are as follows:
a. Stresses in the trussed leg members b. Storm holding capacity of the elevating pinions of the jacking system c. Storm holding capacity of the leg-to-hull locking system, providing the jack-up is equipped with a locking system d. Allowable leg footing reactions to the soil e. Preload capacity f. Overturning
If a jack-up is taut moored as proposed with this invention, lateral deflections of a jack-up, caused by storm induced forces will either stretch or slacken the taut mooring lines, depending on the direction of the deflections. The stretched mooring lines will induce forces against the jack-up which will be counteractive to the forces that cause the deflections. The result will be reduced deflections that will reduce all of the limiting parameters that are outlined above. A static analysis for a jack-up that is taut moored as proposed with this invention will show that all of the usual limiting design parameters can be met for more severe environmental criteria than can be safely resisted if the jack-up were not taut moored.
In order to determine if any of these limiting design parameters will be exceeded, it is usually necessary to perform what is commonly referred to as a “static analysis”. In a static analysis of a jack-up, stresses are calculated for the combination of gravity and storm induced forces. Since the wave forces applied to the jack-up fluctuate as the waves move through the structure, the wave forces used for the static analysis are usually for a phase position that applies the maximum instantaneous overturning moment to the structure.
When it is desired to use a jack-up on locations where it is likely to respond dynamically to the waves that it may encounter, a static analysis may not be adequate to evaluate the acceptability of the jack-up. For those locations it is necessary to perform what is commonly referred to as a “dynamic analysis”. A dynamic analysis determines the magnitude of amplification of the structure's lateral deflections and stresses that are caused by the pulsating nature of the wave forces applied to the trussed legs. If the jack-up's natural period of harmonic motion for lateral deflections on a particular location is large enough for the structure to be resonant with a wave period that commonly exists with large waves, and if these large waves apply enough driving force against the jack-up's legs, then the dynamic amplification of the lateral motions and the resulting stresses in the critical structure may be substantially larger than the same waves would produce if the structure and the waves were not resonant. Providing there is reasonable probability that these resonant waves may occur while the jack-up is on that particular location, the structure must be able to safely withstand the stresses produced by the dynamic amplification.
If a jack-up being evaluated for a given location is planned to be taut moored as proposed with this invention, the magnitude of dynamic amplification will be less than for the same jack-up in the unmoored condition, because the restraints of the taut mooring system will cause the jack-up to have a smaller natural period for lateral motions than it would have if unmoored. The smaller natural period would cause the jack-up to be less synchronous to large waves Therefore, for conditions where dynamic response is likely, the usual limiting design parameters, as listed above, can be met for more severe environmental criteria than can be safely resisted if not taut moored.
When developing new jack-up designs, it is necessary to insure that the design will have an estimated fatigue life that is greater than the anticipated useful life of the jack-up. A jack-up's fatigue life is the estimated years of operation before fatigue cracking is likely to occur. Fatigue cracking is a phenomena that may occur when structures are subjected to cyclic loads that cause stresses to oscillate between tension and compression, at stress levels that are normally acceptable. Most jack-ups have an elevated condition natural period of harmonic motion that is less than the wave period for the jack-up's environmental design criteria. However, smaller waves with shorter periods may be synchronous with the jack-ups period and the oscillating forces from these waves may produce stress reversals that, after many synchronous wave cycles, could result in fatigue cracking of the critical structure of the jack-up. The critical structure for the likelihood of fatigue cracking to occur on most jack-ups is at the member connections at the nodes of the trussed legs.
Many factors affect the likelihood of fatigue cracking to occur during the operating life of a jack-up. Some of these factors are listed below:
a. The accumulated quantity of stress reversals in the critical structure of the jack-up, which is generally proportional to the time in the jack-up's life that is spent at or near the jack-up's maximum water depth, in areas of operation where synchronous waves are likely to occur b. The order of magnitude of the reversing stresses, when they occur, in the critical structure of the jack-up c. The atmospheric temperature during the time periods of the jack-up's life for which synchronous motions cause stress reversals d. The chemical composition and manufacturing procedures used for making the steel to fabricate the critical structure of the jack-up e. The welding consumables, procedures and quality control used for fabrication of the critical connections where cracking is likely to occur on the jack-up f. The structural configuration of the critical connections and the resulting stress concentrations where cracking is likely to occur on the jack-up
Since taut mooring will reduce a jack-up's elevated natural period for lateral motions, it will also reduce the wave size that is likely to produce synchronous motions. The obvious result of these smaller synchronous waves is lower magnitudes of cyclic stress reversals. In addition, stress reversals are less likely to occur for these smaller waves because stress reversals will not occur if the magnitude of cyclic stresses does not exceed the magnitude of the constant stresses resulting from the non cyclic loads. For these reasons, taut mooring systems as proposed with this invention may result in longer fatigue lives for new jack-up designs and existing jack-ups. Alternatively, the incorporation of taut mooring systems as proposed with this invention may allow for new jack-up designs and existing jack-ups to operate with longer legs in deeper waters and still have acceptable fatigue lives.
By logging a jack-up's history of operating water depths, environmental conditions and motion response to waves, an estimate can be made of the durations and magnitudes of stress reversals in the critical structure. With this information, a jack-up's remaining fatigue life can be estimated at any time. Due to abnormally frequent operation on locations where waves regularly produce cyclic stresses that will quickly shorten a jack-up's fatigue life, such estimates may show that some jack-ups will have a fatigue life that is shorter than had been originally estimated by the designer. For other jack-ups, the economically useful life may exceed both the originally estimated useful life and the design's fatigue life. Either situation may require a jack-up to be taken out of service before its economically useful life has expired. Alternatively, a jack-up may have its operational use restricted, such as a reduction in the maximum operating water depth, to insure that cyclic stress reversals will not occur. Restricted use usually means reduced profitability, which may shorten the remaining useful life.
If estimates indicate that a jack-up's remaining fatigue life will be less than its remaining economically useful life, the remaining fatigue life could be extended by using a taut mooring systems as proposed with this invention on locations where cyclic stress reversals are expected to occur. In most cases, the cost of using a taut mooring system as proposed with this invention would be far less than the lost revenues resulting from restricted use or shortened useful life.
As a result of adding a taut mooring system, as proposed with this invention, existing jack-ups will be able to operate safely on some locations that were previously considered unsafe, or they may be able to work year round on some locations where previously they were only allowed to work seasonally. In addition, primarily because of the natural period reducing effects of the proposed taut mooring system, some jack-ups will be able to have their legs extended and survive substantial storms in deeper water depths than they are capable of safely working in, if unmoored.
As described above in one embodiment of the present invention as shown in FIG. 1 the upper end 15 of the mooring line 8 is attached to the hull 4 of the jack-up. In this embodiment it is not necessary to have any additional apparatus for tensioning the mooring lines. The lines are affixed to the hull and tensioned by lifting the hull with the leg jacks 5 . Depending upon the design conditions it may be necessary to add reinforcements to the mooring line attachment locations. The disadvantage with this method is that it may be difficult to secure the lines such that they will have equal tautness.
Future new designs may be developed with plans for attaching more robust taut mooring systems than may be practical for existing jack-ups. For the use of taut mooring systems on floating structures, it is necessary to have a means to tighten the mooring lines, such as chain ratchets. Although these tightening means may be used for tightening the mooring lines on a jack-up, they are not necessary. For a jack-up, the mooring lines could be secured to the jack-up with equal slack in each line, then the jack-up could be elevated on its legs a short distance with the jacking system, using its existing capabilities just enough to provide the desired tautness to the mooring lines. Gages or other monitors can be provided to track the tension developed in each mooring line. The disadvantage with this method is that it may be difficult to secure the lines such that they will have equal tautness.
A further improvement taught by the present invention is a method and apparatus for securing the mooring lines to the jack-up is to attach the mooring lines to additional jacking units that climb leg chords that have been selected for mooring. As shown in FIGS. 8 and 10 an additional benefit of using separate jacking units 16 to secure the mooring lines 8 to the legs 2 is that these additional jacking units 16 can be connected with pins 17 or by other connections to the top of the existing jack units 5 during location moves to provide additional elevating capacity. These additional jacking units or mooring jacks 16 will be located above and could be either independent of or severable from the hull 4 and standard leg jacks 5 or otherwise linked to the hull by chains, cables or other attachments. See FIGS. 3 and 5 , and see also FIGS. 8 and 10 . The mooring jack units would likely be of the same design as the existing elevating gear units. It is contemplated in the present invention that the mooring jacking unit 16 would be comprised of one or more climbing pinions 18 each with gear trains and motors mounted in a frame 19 with leg cord guides above and below the gear units. Mooring lines 8 will be attached to the mooring jacks 16 by a suitable connection that will be aligned with the centroid of the leg chord to avoid applying torsion to the leg chords with the mooring forces. As shown in FIGS. 7 , 8 , 9 , 10 and 11 . Mooring pad-eyes 20 are welded onto the mooring jacks 16 or mooring jack frame 19 . The mooring pad-eye 20 is provided with an apature for receiving a pinned shackle 21 for connection to the mooring line 8 . As described before, the mooring line 8 can be a chain, cable or other synthetic or composite line. In the embodiment that does not use the additional or auxiliary mooring jacks 16 a similar mooring pad-eye 20 would be fixed to or mounted to the hull 4 of the jack-up. As previously described in this embodiment the standard leg jacks 5 would be utilized for tensioning and making taut the mooring lines 8 .
The mooring lines would be attached to the mooring jacking units before the platform is elevated to the desired wave clearance. With the mooring jacks positioned just above the jack-up's upper guides, the mooring lines would be connected with slack such that the mooring lines would become taut when the jacking units are raised to a position that would locate them a short distance above the jack-ups upper guides after the jack-up is at the desired elevation for operations. The mooring jacking units would then be powered to climb the leg chords to tighten the mooring lines. The tautness of the mooring lines would be individually equalized by jacking each mooring jacking unit until its attached mooring line is taut. With the use of additional mooring jacks, the desired tautness could be readjusted at any time without the need for jacking the platform on the legs.
An additional benefit of using jacking units to secure the mooring lines to the legs is that these jacking units can be connected with pins or other means to the top of the existing jacking units during location moves to provide additional elevating capacity. The additional elevating capacity would result in an increase in variable loads when jacking the platform above the sea surface. This is highly desirable for existing jack-ups because most have had their variable loads reduced due to weight increases caused by modifications and machinery upgrades.
If so planned, the analysis for the new design would include taut moored conditions and the taut mooring attachment structure would be a part of the initial design.
It should be apparent that many changes may be made in the various parts of the invention without departing from the spirit and scope of the invention and the detailed embodiments are not to be considered limiting but have been shown by illustration only.
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A taut mooring system for use on a mobile offshore jack-up platform while it is in an elevated operating condition. The elevated operating condition is with the hull jacked up a safe distance above the highest anticipated wave crests, on vertically movable legs which extend to the ocean floor. The mooring system consists of: radially spaced mooring line attachment means on the structure of the platform; suction piles that are radially spaced around the platform, consistent with the radial spacing of the mooring line attachment means; and taut mooring lines which radially connect the suction piles to the attachment means. The flexibility of the taut mooring system provides the ability to coact with the platform's free standing storm resistance capabilities, yielding enhanced capabilities that will enable the platform to safely resist storm induced forces that the platform would not normally be capable of withstanding, and to enable the platform to be used with longer legs in deeper water.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates generally to drain opening devices, and specifically to the use of compressed air to push obstructions from clogged drains.
BACKGROUND OF THE INVENTION
[0002] Water drains typically get clogged due to materials becoming lodged in traps, joints, and other locations. Typically the material causing the blockage or clogging can be freed by applying hydraulic pressure, liquid or gaseous, on the upper region of the drain. Numerous devices available for applying pressure to the blockage, yet they are all deficient in one manner or another.
[0003] Devices commonly referred to as “plungers” comprise a force cup with a handle attached thereto. The force cup is brought into contact with the drain entrance and pushed down by the handle, thereby forcing water to engage the clog with hydraulic pressure and push it down the drain and ultimately out of the way. A force cup device typically does not have sufficient volume to apply sustained and increasing pressure so as to be effective against the blockage material.
[0004] The combination of low and unsustained pressure exerted by force cup devices, and the required reciprocating motion of the plunging action of plungers using force cups, which causes splashing and messy loss of water from the immediate vicinity of a clogged drain, has led to the development of other types of devices. For example, piston devices comprising a piston slidably received within a circular cylinder are an improvement over force cup devices. The piston devices typically comprise a fixed tube with a piston that transits therein to apply pressure at the exit end of the tube. These devices are often adequate for unclogging drains. yet they require many parts and multiple seals thereby increasing the cost of manufacture and the susceptibility of failure during use. Each piston must have a seal between the piston and the cylinder it slides in so as to be effective. The piston must also be sealed to the push rod. Such devices, while functional, have yet to receive widespread acceptance over the simple force cup plunger alone.
[0005] There has been a long felt need in the realm of the plumbing arts for a device suitable for removing blockages from drains in a way that is economical to manufacture, sell, and use, and which is reliable, efficient, and sanitary.
SUMMARY OF THE INVENTION
[0006] According to the present invention there is disclosed a drain clearing apparatus comprising a drain engaging element adapted to be mounted to a drain; a hollow shaft, attached at one end to the drain engaging element; an air hose connector attached to the hollow shaft at an opposite end from the drain engaging element; and a flexible air hose having an air hose connector for conveying compressed air from a compressed air source. The drain clearing apparatus also has a drain engaging opening adapted to the drain engaging element so as to make an airtight connection with the opening of the drain. The drain clearing apparatus includes the feature of having the hollow shaft attached to the drain engaging element by a threaded coupling, and it uses a force cup at the drain engaging element. The hollow shaft of the drain clearing apparatus is rigid and is able to transmit axial force and to contain compressed air within itself, and the air hose connector on the hollow shaft couples with an air hose that connected to a compressed air source, the air source being an air compressor, and the air line connector is a quick connect connector.
[0007] According to the present invention there is disclosed a method for clearing blockage from a drain comprising the steps of providing a drain engaging element adapted to be mounted to a drain; attaching a hollow shaft at one end of the drain engaging element; affixing an air hose connector to an end of the hollow shaft at an end opposite from the drain engaging element; attaching a flexible air hose, having an air hose connector, to the air hose connector affixed to the hollow shaft; placing a drain engaging element in airtight contact with a drain; and directing a flow of compressed air through the flexible hose, air hose connector, and hollow shaft to the drain engaging element. The method includes the further step of adapting a drain engaging opening to the drain engaging element, and attaching the drain engaging element to the hollow shaft by a threaded coupling. The method includes the steps of using a force cup as the drain engaging element and making the hollow shaft sufficiently rigid to transmit axially directed force and sufficiently rigid to contain high pressure air within itself. The method including connecting a source of compressed air to the flexible air hose and turning on the source of compressed air, and using a portable air compressor as the source of compressed air. The final steps of the method include using a quick connect connector as the air line connector and sealing the sealing the drain engaging element upon the blocked drain and directing the compressed air to push the blockage from the drain.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description taken in conjunction with the accompanying figures (FIGS.). The figures are intended to be illustrative, not limiting. Certain elements in some of the figures may be omitted, or illustrated not-to-scale, for illustrative clarity. The cross-sectional views may be in the form of “slices”, or “near-sighted” cross-sectional views, omitting certain background lines which would otherwise be visible in a “true” cross-sectional view, for illustrative clarity.
[0009] FIG. 1 is an oblique view of the invention showing the main parts.
[0010] FIG. 2 is an orthogonal partial cutaway view of the main part of the invention, showing internal details.
[0011] FIG. 3A is a cross sectional exemplary view of the invention in use against a drain blockage in a toilet bowl.
[0012] FIG. 3B is a cross sectional exemplary view of the invention in use against a drain blockage in a water basin.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] In the description that follows, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by those skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. Well-known processing steps are generally not described in detail in order to avoid unnecessarily obfuscating the description of the present invention.
[0014] In the description that follows, exemplary dimensions may be presented for an illustrative embodiment of the invention. The dimensions should not be interpreted as limiting. They are included to provide a sense of proportion. Generally speaking, it is the relationship between various elements, where they are located, their contrasting compositions, and sometimes their relative sizes that is of significance.
[0015] In the drawings accompanying the description that follows, often both reference numerals and legends (labels, text descriptions) will be used to identify elements. If legends are provided, they are intended merely as an aid to the reader, and should not in any way be interpreted as limiting.
[0016] Referring now to FIG. 1 , the main elements of a drain clearing apparatus 10 are shown in oblique view. The drain clearing apparatus 10 includes a force cup 14 made of flexible and pliable material such as natural or synthetic rubber, a rigid handle portion 16 that is hollow, a quick connector 20 consisting of a male portion 20 a and a female portion 20 b, another quick connector 30 , and a flexible tube portion 24 that connects to a light weight, portable air compressor 26 . The air compressor 26 is not part of the invention, but the inventor envisions that the invention 10 itself, when purchased, might be supplied with an air compressor ideally matched to the drain clearing apparatus 10 and its operation.
[0017] FIG. 2 shows the drain clearing apparatus 10 of the present invention in partial cutaway, orthogonal view. The force cup portion 14 is made of flexible polymeric material such as rubber. Force cup 14 consists of two main parts, an upper plenum chamber 15 and a lower invertible cup 13 having a circumferential orifice 12 . The function and operation of the invertible cup portion 13 will be described hereinbelow. Also shown in FIG. 2 is the rigid handle portion 16 , which is connected by a threaded coupling 23 to the force cup 14 , or by any other suitable means. The rigid handle 16 is circularly cylindrical in cross-section and contains therein, an axially centered, inner passageway 17 communicating between the upper plenum portion 15 of the force cup 14 and the rigid handle's uppermost end 18 , which has attached thereto the male portion 20 a of a quick connect coupling 20 of the sort commonly used for conveying fluids, both liquid and gaseous, from one conduit to another. In the present case, the male portion 20 a of a quick connect coupling 20 is connected to the flexible compressed-air conveying hose 24 , by means of the female portion 20 b of the quick connect coupling, so that the flexible compressed-air conveying hose 24 is connected to the rigid handle 16 . The male portion 20 a of the quick connect coupling 20 is attached to the rigid handle portion 16 by reliably air-tight means (not shown) such as screw threading, adhesive bonding, polymer welding, or any other of many conceivable techniques, the net result being that the communicating passageway 17 is continuous from the mouth 19 of the male coupling portion 20 a to the lower end 11 of the rigid handle 16 inside the plenum 15 . The function of the passageway 17 is to communicate pressurized air from the flexible hose 24 , by means of the quick connect coupling 20 when its two components 20 a 20 b are engaged, to the force cup 14 . While the quick connect coupling 20 has the male portion 20 a connected to the handle 16 and the female portion 20 b connected to the hose 24 , it is within the terms of the present invention to mount the male portion 20 a to the hose 24 and the female portion 20 b to the handle 16 .
[0018] At distal end 28 of the flexible hose 24 , there is disposed a second quick connect coupling 30 wherein the male portion 30 a is secured to the flexible hose 24 to engage with a corresponding female quick coupling portion (not shown) that is affixed to an outlet port of the portable air compressor 22 , as shown in FIG. 1 . Compressed air, denoted by the arrow 34 located at the end 11 of the air-conveying passageway 17 inside the rigid handle 16 , moves from the compressor 26 by way of the flexible tube 24 , and quick connects 20 and 30 , to the plenum chamber 15 of the force cup 14 .
[0019] During use of the drain clearing apparatus 10 , the compressed-air conveying flexible hose 24 is connected at one end by means of the quick connect coupling 30 to an air compressor 26 , and at its other end 21 to the rigid handle 16 by means of the quick connect coupling 20 . As will be shown in detail hereinbelow, the user of the drain clearing apparatus 10 causes the force cup portion 14 of the invention to be brought into air tight contact with the region adjacent the drain of a toilet or water basin wherein the outflow of water is obstructed by a blockage. The user exerts axially directed force upon the rigid handle 16 so as to compress the flexible force cup 14 against a surface that is immediately adjacent to and surrounding the drainage passageway so as to bring about an air tight seal against the loss of fluid or gaseous pressure inside the force cup 14 which is intended to work against the object or material that is obstructive of the flow inside of said drain. The air compressor 26 is then turned on so that air pressure and air volume are brought to bear against the blockage material and against any water that is disposed upstream of said blockage material, thereby pushing said blockage to a wider part of the drain.
[0020] The unique operation of the drain clearing apparatus 10 becomes more specifically evident in the orthogonal cross sectional illustrations of FIGS. 3A and 3B . FIG. 3A shows in cross sectional schematic view a toilet bowl 40 having an outflow drain segment 42 , containing therein water 44 that is blocked from outflow by an obstruction 46 . The invertible flexible cup portion 13 of the force cup 14 is shown engaging the walls 41 of the neck 43 of the toilet drain 42 , thereby creating a seal against the outflow of fluid pressure, water or air, from inside of the force cup. Arrow 47 , shown located within the plenum 15 of the force cup 14 . As compressed air 47 enters the volume defined by the inside of the plenum 15 and the region 48 above the water surface 45 , the pressure of the air is transmitted by those processes that are well-known among those who are skilled in the hydraulic arts such that a net force F is conveyed to the blockage obstruction 46 . The final result is that the force F pushes the blocking obstruction 46 out of contact with the walls 41 of the outflow drain 42 , and thence to a wider part of the drain, thereby affecting the desired result, which is removal of the obstruction from the water drain of the toilet bowl 40 .
[0021] FIG. 3B shows the operation of the drain clearing apparatus 10 in relation a water basin 50 , shown in schematic cross sectional view. The drain portion 52 of the basin 50 is shown with an obstructing mass 56 disposed within the drain so as to block the passage of trapped water 54 . In the view shown in FIG. 3B , the invertible flexible cup 13 of the force cup 14 is shown inverted to a position inside of the plenum 15 . In this way, when the user of the invention pushes the force cup 14 , the invertible cup 13 gets creates a seal against the flat surface 51 that surrounds the drain region 52 of the basin 50 . The sealing effect of the invertible cup 13 against basin surface 51 prevents the flow of fluids, liquid or gaseous, from within the volume that is defined by the inside of the plenum 15 and the volume 58 inside the drain and above surface 55 of the trapped water 54 . Thus, as incoming compressed air, which is indicated by arrow 57 , fills the volume 58 , the hydraulic pressure, or pneumatic pressure, of the air is transmitted by those processes that are well-known to those who are skilled in the hydraulic arts such that a net force F′ is conveyed to the blockage obstruction 56 . The final result is that the blocking obstruction 56 is pushed downward along the walls 53 of the outflow drain 52 to a wider portion thereof, thereby ultimately affecting the desired result, which is removal of the blockage 56 from the water drain 52 of the basin 50 .
[0022] Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, certain equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described components (assemblies, devices, etc.) the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiments of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several embodiments, such feature may be combined with one or more features of the other embodiments as may be desired and advantageous for any given or particular application.
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A drain cleaning device that uses compressed air to clear obstructions in the drain pipes of water basins, toilets and the like. The drain cleaning device consists mainly of a force cup, a handle, flexible pipes for conveying compressed air, and quick connect couplings.
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This is a division, of application Ser. No. 08/085,844, filed on Jun. 30, 1993 now abandoned.
FIELD OF INVENTION
This invention relates to a material which exhibits both hydrophobic and hydrophilic characteristics, defined herein as a "biphasic" material. More particularly, the invention relates to a biphasic material in the form of a flat or tubular membrane, hereinafter referred to as a biphasic membrane. The invention is also concerned with a catheter containing multi-parameter sensors, herein designated a multi-parameter catheter, having an outer wall at least part of which is made from a biphasic membrane; an apparatus comprising such a catheter in combination with a device for introducing the catheter into a patient's blood vessel and a vacuum rig apparatus for introducing a liquid into a desired space.
BACKGROUND OF THE INVENTION
Invasive sensors for determining the concentration of various analytes in body fluids, particularly the concentration of gasses such as oxygen and carbon dioxide in blood, have been proposed in the art.
U.S. Pat. No. 3,905,888 discloses an electrochemical sensor for determining the oxygen partial pressure in a biological medium comprising a flexible plastic tube which is permeable to oxygen and houses a pair of electrodes surrounded by an electrolyte.
Sensors for the determination of pH and pCO 2 normally comprise one or more optical fibers in association with a suitable indicator for the parameter under investigation.
U.S. Pat. No. 4,200,110 discloses a fiber optic probe which includes an ion permeable membrane envelope which encloses the end of a pair of optical fibers. The operation of the probe depends upon the optical detection of a change in color of a pH sensitive dye. U.S. Pat. No. 4,943,364 discloses a fiber-optic probe for measuring the partial pressure of carbon dioxide in a medium comprising a hydrolyzed dye/gel polymer in contact with a bicarbonate solution enveloped in a membrane covering the distal end of the fiber.
U.S. Reissue Pat. No. 31,879 discloses a method for measuring the concentration of an analyte in a sample which involves measuring a change in the color characterization of a fluorescent indicator attached to an optical fiber, without or with a gas-permeable membrane.
Commonly assigned U.S. Pat. No. 4,889,407 discloses an optical waveguide sensor for determining an analyte in a medium, which sensor comprises an optical waveguide having a plurality of cells arranged in an array which substantially covers the cross-sectional area of the waveguide, each of said cells containing an indicator sensitive to said analyte.
When a probe, such as one of those disclosed in the above prior art, is used invasively, it is usually introduced into a body lumen, for example a blood vessel, with the aid of an introducer and, to protect the probe itself, avoid contamination, maintain sterility and also facilitate introduction, the probe is usually accommodated within an elongated tubular catheter.
The prior art patents mentioned above disclose sensors adapted to determine a single analyte. However, there is a need in the art for a single device which is capable of determining and monitoring a number of blood parameters, for example, pH, pO 2 , pCO 2 and temperature, and which has a small enough diameter to be inserted into a blood vessel.
U.S. Pat. No. 4,727,730 discloses a blood pressure monitoring apparatus comprising a single fiber probe that interrogates three dye wells each using a fluorescent dye. Blood pressure is monitored with the aid of a diffraction grating.
U.S. Pat. No. 4,854,321 discloses a single probe having multiple dye wells for monitoring blood gases.
U.S. Pat. No. 4,279,795 discloses a hydrophilic-hydrophobic graft copolymer formed by the copolymerization of a free radical polymerizable vinyl monomer capable of forming a hydrophilic polymer and a hydrophobic macromolecular compound.
By using a biphasic membrane as described and claimed herein, it is possible to incorporate sensors for the determination and monitoring of pH, pO 2 , pCO 2 and temperature in a single multi parameter catheter which is narrow enough to be inserted safely into a patient's blood vessel.
Since it is important to avoid contamination and direct operator contact when introducing the catheter into a patient's blood vessel, the invention also provides a device, or introducer, for said introduction.
U.S. Pat. No. 4,906,232 discloses an intravascular delivery device comprising seal means, a delivery assembly having an inner sleeve and stop means.
U.S. Pat. No. 4,960,412 discloses a valve assembly for a catheter introducer.
It has now been found that optimum results are obtained from a multi-parameter catheter if at least part of the tubular wall or outer sheath of the catheter is made from a biphasic membrane as disclosed herein.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a biphasic material comprising a layer of microporous hydrophobic substance having micropores which are filled with a hydrophilic substance which when hydrated forms a gel and allows the passage of water-bound ions.
In a preferred embodiment, the layer of microporous hydrophobic substance is a membrane made from a hydrophobic polymer, for example polyethylene, which may be flat or tubular. The substance allows the passage of gasses but, because of its hydrophobicity, the passage of liquid water bound molecules or ions is not possible. Since hydrogen ions require liquid water molecules for transport, the membrane is also impermeable to hydrogen ions. To make the microporous membrane permeable to hydrogen ions, the micropores, a typical size for which is 0.1 micron, are filled with a hydrophilic substance, for example a polyacrylamide, which when hydrated forms a gel and allows the passage of water-bound ions. Thus the membrane is biphasic, i.e. both hydrophobic and hydrophilic.
Due to their high water content, many hydrogels are inherently biocompatable. Also, a hydrogel provides a medium which is permeable to low molecular weight molecules, ions, and gases; although it inhibits the transfer of high molecular weight blood components, which would interfere with the performance of sensors. This combination of properties make a hydrogel satisfactory for use in invasive sensors, particularly pH sensors. However, in general, hydrogels are mechanically weak. This latter disadvantage is overcome by the present invention wherein a preferred hydrogel is incorporated into a microporous layer of substance having the desired mechanical strength to be used as the outer sheath or wall of an invasive catheter. The hydrogel fills the micropores of the microporous layer.
The preferred substance for the microporous layer is high density polyethylene, which is a hydrophobic substance. Another substance which may be used for the microporous layer is polypropylene.
A preferred use for the biphasic membrane of the present invention is as the outer wall of a catheter containing multi-parameter sensors as described hereinafter.
Accordingly, the invention also provides a multi-parameter catheter for the in vivo determination of multiple parameters in a patient's blood comprising an elongated tube with a distal hollow chamber terminating in a distal end, the wall of said chamber being defined at least in part by a biphasic membrane made from a layer of microporous hydrophobic substance having micropores which are filled with a hydrophilic substance which when hydrated forms a gel which allows the passage of water-bound ions and said chamber containing a plurality of sensors mounted sequentially from said distal end within a hydrophilic medium.
In a preferred embodiment of the catheter the sequentially mounted sensors comprise, in sequence from the distal end of the chamber, an optical fiber Ph sensor, an optical fiber pCO 2 sensor, a thermocouple temperature sensor and a pO 2 sensor. The pO 2 sensor may be an electrochemical pO 2 sensor as described herein or a fluorescent pO 2 sensor.
Preferably the biphasic membrane is a microporous polyethylene tube having micropores which are filled with a polyacrylamide hydrogel, the hydrophilic medium within which the sensors are mounted is a polyacrylamide hydrogel and the distal end of the chamber is sealed by a solid plug made from a thermoplastic polymer.
The invention also provides an apparatus for the in vivo, determination of multiple parameters in a patient's blood comprising, in combination, a catheter as described above and a device for introducing the catheter into a patient's blood vessel, which device comprises a first elongated flexible hollow tube having a distal end, a proximal end and a distal portion terminating in said distal end, a second elongated extension tube concentrically mounted within the distal portion of the first tube for telescopic extension beyond the distal end of the first tube and retraction within the first tube, so that when the second tube is fully extended it completely envelopes the catheter and when it is retracted the catheter is exposed, the device also including locking means for locking the second tube in the extended or retracted position as desired, and means for introducing a sterile liquid within said second tube to surround the catheter when it is within the tube.
In the above apparatus the introducer device preferably has a connector at the proximal end thereof, which connector is attached to leads from each sensor of the catheter. The connector is adapted to form a junction with another connector attached to a suitable monitor for monitoring the parameters under investigation by the sensors. Preferably the junction formed by the connectors is protected by a barrier as described and claimed in commonly assigned U.S. Pat. No. 5,230,031.
The invention further provides a vacuum rig apparatus for introducing a liquid into a space defined by a shaped article, which apparatus comprises a series of interconnected vessels attached through a port to a vacuum line, the vessels comprising a first vessel connected to a second vessel, which second vessel is adapted to hold said shaped article and is a hollow tube with a proximal end and a distal end, said distal end being integral with a "U" shaped tube having an open distal end which projects into a space defined by a third vessel which is a reservoir for liquid and has a distal end with a first port and a second port, said first port providing a drain adapted to be plugged or opened as desired and said second port connected to a fourth vessel having first and second sealable ports and a third port for connecting the apparatus to a vacuum line and a tubular conduit connecting the second vessel, from a port adjacent the proximal end thereof, to the fourth vessel, so that said conduit, second vessel, "U" shaped tube, third vessel and fourth vessel form a closed circuit, the apparatus being tiltable about a point midway along the second vessel so that liquid in the reservoir initially at a level below the end of the "U" shaped tube flows into and along the "U" shaped tube into the second vessel to surround the shaped article and fill the space therein when a vacuum is applied to the apparatus.
Preferably, the connection between the first vessel and the second vessel is a tubular conduit which provides a releasable fluid-tight connection from a port in the first vessel to a port at the proximal end of the second vessel.
The vessels of the vacuum rig apparatus have transparent walls which may be made of glass or a transparent plastic.
In a preferred embodiment of the apparatus the tubular second vessel is perpendicular to the third vessel which also is preferably tubular in shape; and the tubular conduit connecting the second vessel to the fourth vessel is preferably diagonal with respect to the third vessel.
The vacuum rig apparatus may be used for filling a chamber of a multi-parameter catheter with a hydrophilic medium in which case the "shaped article" is the tubular chamber which houses the sensors of the catheter and the space defined thereby is the space surrounding the sensors, and the liquid in the reservoir is a hydrogel-forming liquid. The apparatus also may be used for filling the cells in an optical fiber pH sensor or pCO 2 sensor; and for introducing the electrolyte into an electrochemical pO 2 sensor.
The vacuum rig apparatus additionally may be used to introduce a hydrophilic substance into the micropores of a microporous substrate to form a biphasic membrane according to the invention.
Accordingly the invention still further provides a method for introducing a liquid into a space defined by a shaped article which comprises placing the shaped article in a vessel which is part of a vacuum rig apparatus comprising a liquid reservoir perpendicular to the vessel, introducing liquid into the reservoir, applying a vacuum to the vessel to evacuate gas from the space, tilting the apparatus so that liquid from the reservoir enters the vessel and fills the space.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more particularly described with reference to preferred embodiments illustrated in the accompanying drawings, in which:
FIG. 1 is a schematic side view, partly in cross-section, of a multi-parameter catheter having an outer sheath embodying a biphasic membrane made from the biphasic material according to the invention;
FIG. 2 is an enlarged side view of a pH sensor included in the catheter of FIG. 1;
FIG. 3 is an enlarged side view of a pCO 2 sensor included in the catheter of FIG. 1;
FIG. 4 is an enlarged side view of an electrochemical pO 2 sensor included in the catheter of FIG, 1;
FIG. 5 is an enlarged side view of a thermocouple included in the catheter of FIG. 1;
FIG. 6 is a schematic side view of a preferred device for introducing a catheter of FIG. 1 into a patient's blood vessel.
FIGS. 6A, 6B, 6C, 6D are enlarged views of the device of FIG. 6 showing the features thereof in more detail;
FIG. 7 is a schematic panoramic view of a vacuum rig apparatus; and
FIG. 8 is a view of part of the vacuum rig apparatus in the tilted position.
DETAILED DESCRIPTION OF THE INVENTION
A particularly preferred embodiment which utilizes a biphasic membrane according to the present invention is a system for determining certain parameters in the blood of a patient. The parameters are determined by various sensor devices incorporated in a single catheter which is adapted to be inserted into the bloodstream of the patient and, for convenience, the system is designated herein as a multi-parameter catheter system. The biphasic membrane of the invention is used to form at least a part of the tubular wall or outer sheath which envelopes the sensors in the catheter. A device for introducing the catheter into a patient's blood vessel is also described.
Commonly assigned U.S. Pat. No. 4,889,407, acknowledged above, describes and claims an optical waveguide sensor for determining an analyte in a medium, for example, blood, which sensor comprises an optical waveguide, preferably an optical fiber, having a portion to be brought into contact with said medium, said portion having a plurality of cells arranged in an array which substantially covers the cross-sectional area of the fiber, each of the cells containing an indicator sensitive to the analyte. This sensor is particularly suitable for the determination of pH and pCO 2 in blood, and, preferably, a sensor as described and claimed in U.S. Pat. No. 4,889,407 is incorporated in the multi parameter catheter system utilizing the biphasic membrane of the present invention.
FIG. 1 of the accompanying drawings illustrates a multi-parameter catheter 1 comprising a hollow tube defined by a distal portion sheath 2 terminating in a distal end 3 which is sealed by a thermoplastic polymer plug 4 to form a closed chamber 5. The preferred method for sealing the tube with a thermoplastic polymer plug and the resulting tubular assembly is described and claimed in commonly assigned U.S. patent application Ser. No. 887,993 (U.S. Pat. No. 5,280,130). The proximal portion wall 6 of the tube is made from solid non-porous polymeric tubing, for example, polyethylene tubing, and the distal end thereof forms a butt-joint with the sheath 2.
The sheath 2 is a biphasic membrane comprising a layer of a microporous hydrophobic substance the micropores of which are filled with a hydrophilic hydrogel. Also, since the sheath portion of the catheter will be in contact with body fluids, particularly blood, when the catheter is in use, preferably heparin is covalently bound to the outer surface thereof to prevent blood clots.
Preferably the microporous substance is a high density polyethylene and the sheath is a microporous polyethylene hollow fiber (MPHF) with an internal diameter of from about 425 to 475 microns, a maximum external diameter of about 500 microns, and a porosity of about 40%. The preferred hydrophilic substance which fills the micropores of the MPHF is a polyacrylamide hydrogel. The method of filling the micropores with the hydrogel is described hereinafter.
Mounted within the tube, in sequence from the distal end are four sensors, a pH sensor 7, a pCO 2 sensor 8, a temperature sensor 9, and a pO 2 sensor 10. The sensors are mounted in the desired staggered relationship primarily to reduce the diameter of the catheter. This is because the distal end or tip of each sensor is flared, even though the flare is not immediately apparent at the scale shown in the drawings, and adjacent side-by-side alignment would result in an unacceptable increase in diameter at the tips of the sensors. Also, in the case of the pH and pCO 2 sensors, it is desirable to stagger the positioning of the cells in the optical fibers to avoid possible interference of signals.
The preferred staggered sequence of sensors is illustrated in FIG. 1; but other sequences are also possible for operable sensors.
Within the chamber 5 the sensors are surrounded by a hydrophilic medium, preferably a polyacrylate hydrogel containing phenol red indicator. A similar polyacrylate/phenol red hydrogel is impregnated into the cells of the pH sensor.
If desired the sensors may be secured within the catheter by an adhesive plug (not shown).
To reduce interference or noise from extraneous radiation the proximal portion of the catheter is back-filled with a radiation-opaque coating 12, for example of carbon black, the distal end of the opaque coating being adjacent to the distal end of the solid polyethylene tubing 6. Preferably, the catheter is coated by applying a suspension of carbon black in silicone, previously de-gassed, through a syringe in a manner known in the art. The coating is cured by heating in an oven at 40° C. for about 2 hours. Curing is conducted at the sensor end first to prevent tracking of carbon black into the sensors. Alternatively, the coating may be an UV-curing silicone rubber containing carbon black and the curing is conducted at a suitable UV intensity.
The portion of the catheter proximal to the portion containing the sensors has an outer sheath of polyethylene tubing 13.
The individual sensors are illustrated in more detail in the enlarged views of FIG. 2-5.
FIG. 2 illustrates a preferred pH sensor 7 which comprises an optical fiber 14 having a helical array of cells 15 which substantially covers the cross-sectional area of the fiber. The number of cells in the array may vary up to any desired maximum. Preferably the pH sensor of the invention contains five cells. Each of the cells contains a pH sensitive indicator, preferably phenol red in a gel. The filling of the cells is accomplished by use of a vacuum rig apparatus as described herein. This type of sensor is described and claimed in U.S. Pat. No. 4,899,407. Optical radiation transmitted along the fiber is reflected by a mirror 16 embedded close to the distal end 17 of the fiber and the emitted signal is returned along the fiber and through the indicator-containing cells to an appropriate monitor which interprets the signal to give an indication of the pH of the medium around the distal portion of the catheter. An optical fiber sensor having an embedded mirror is described and claimed in commonly assigned U.S. patent application Ser. No. 887,457 (U.S. Pat. No. 5,257,338).
FIG. 3 illustrates a preferred pCO 2 sensor 8 which comprises an optical fiber 18 having an array of cells 19 which substantially covers the cross-sectional area of the fiber and a mirror 20 embedded close to the distal end 21. These features are similar to those in the pH sensor described above. However, the preferred number of cells in the pCO 2 sensor is three and each of these cells is filled with an appropriate indicator, preferably phenol red, in a solution which is a source of bicarbonate ions. Preferably the solution is sodium carbonate which is convened to the bicarbonate after incubation. The sensor is enveloped by a tubular membrane 22 of carbon dioxide-permeable polymer, preferably polyethylene.
FIG. 4 illustrates an electrochemical pO 2 sensor 10 comprising two elongate insulated conductors 23, 24, each having a stripped distal portion, the exposed metal of which provides an active surface forming an anode 25 and cathode 26, respectively. Preferably the anode has a longer active surface than the cathode. In the embodiment illustrated in FIG. 4 the insulated conductor forming the anode is folded into a "U" shape 27 such that the distal end surface of the anode faces the distal end surface of the cathode. The advantage of this configuration is that it reduces or eliminates the consumption of uninsulated metal from the active surface of the electrodes other than the distal end thereof, which was a problem frequently encountered in prior art electrochemical cells. An electrochemical pO 2 sensor such as that illustrated in FIG. 4 is described and claimed in commonly assigned U.S. patent application Ser. No. 07/887,615 (U.S. Pat. No. 5,262,037). An alternative embodiment (not illustrated) which overcomes the above described problem is an electrochemical cell in which the electrodes are aligned in substantially parallel relationship alongside each other, again with the active surface of the anode being longer than the active surface of the cathode, and wherein the insulated portion of the conductor is covered or coated with an additional layer of insulation. This double insulation prevents short-circuiting caused by pinholes or other defects in the original (single layer)insulation.
In the preferred embodiment the anode and cathode are made of silver wire. Other conductors, such as platinum may be used.
The anode and cathode are contained within a compartment 28 defined by an oxygen gas permeable membrane 29 that permits oxygen to diffuse therethrough. The distal end of the compartment is sealed with a plug 30 made from a thermoplastic polymer. The gap 31 between the anode and the cathode, as well as the rest of the compartment surrounding the electrodes, is filled with an electrolyte, for example a buffered potassium chloride aqueous solution. The electrochemical cell formed by the anode, cathode and electrolyte is an oxygen sensor whereby concentration of oxygen in the surrounding medium, for example, blood, is measured by changes in electric current flow across the gap 31. The current is generated from a source (not shown) connected across the proximal ends of the conductors and changes are measured by a current measuring device in circuit with the source.
FIG. 5 illustrates a temperature sensor 9 which comprises a thermocouple formed from the stripped distal portion 32 of two insulated metal wires 33, 34. The distal ends of the wires are welded together to form a welded tip. Preferably the wires are 0.05 mm. copper wire and 0.05 mm. copper/nickel alloy wire and both wires are insulated with a polyurethane coating 36. The stripped portion of the wires is enveloped by a plastic sleeve 37. The thermocouple temperature sensor is a conventional device in the art.
The multi-parameter catheter described above and illustrated in FIG. 1 of the drawings is adapted to be introduced into a blood vessel of a patient, through a cannula previously inserted in the vessel, with the aid of an introducer device such as that illustrated in FIG. 6 of the drawings.
FIG. 6 schematically illustrates an apparatus comprising the combination of a catheter 1 and an introducer device 60. The introducer comprises a first elongated flexible hollow tube 61 having a distal end 62 and a proximal end 63, and a second elongated extension tube 64. The second tube has an outer diameter the same as or slightly less than the inner diameter of the first tube, and the second tube is concentrically mounted within a distal portion of the first tube so that it may be telescopically extended beyond the distal end of the first tube or retracted within the distal portion of the first tube. The various positions of the extension tube relative to the catheter are illustrated in FIGS. 6A-6D.
The introducer also comprises, at its distal end, a male luer noble 65 associated with a rotatable locking collar 66. The luer is adapted to connect the distal end of the introducer to a tonometer (not shown) in which the sensor-containing distal portion of the catheter is stored and calibrated prior to use. The introducer is locked to the tonometer by tightening the collar 66 and released from the tonometer by loosening the collar.
The introducer further comprises a slidable wing 67 mounted on the extension tube. The slidable wing enables the device to be securely attached to the body of the patient, preferably by taping, after the catheter is properly introduced into a blood vessel. A similar wing 68, which may be fixed or slidable, is mounted on the first tube for a similar purpose.
Located along the second tube and concentrically fixed thereto is a Y junction 69 having an angled port or outwardly extending arm 70 which terminates in an obturator 71. The obturator is adapted to be connected to a source from which sterile liquid may be introduced into the second tube to surround the catheter when it is within the tube. Sterile liquid is introduced to flush the system and remove air bubbles. Also, the angled port may be used for taking blood samples or monitoring blood pressure. Thus the extension tube and the associated Y junction make it easier to access the proximal portion of the catheter away from the site of insertion. A cannula protects the site of entry of the catheter into a blood vessel, usually the radial or femoral artery. A clamp nut 72 which threadably tightens the Y junction about the second tube through an O-ring 73 (see FIG. 6D) also acts as a locking means for locking the second tube relative to the first tube. The clamp nut has to be loosened to enable the second tube to be moved telescopically with respect to the first tube.
When the second tube is in a fully extended or partially extended position relative to the first tube, as indicated, for example, in FIG. 6, and FIGS. 6A, 6B and 6D, a portion 74 of the second tube between the clamp nut and the distal end 62 of the first tube is exposed and this exposed portion preferably has gradations, preferably in cm., to enable the operator to determine the depth of penetration when the catheter is inserted in a patient's blood vessel. Also located on the exposed portion of the second tube is a removable stop 75 which facilitates positioning of the catheter when it is inserted in a patient's radial artery. As shown in the cross-sectional view of FIG. 6D, leads 76 from the sensors in the catheter, both optical fibers and metal conductors, are connected to terminals 77, i.e. sockets and ferrules, in a connector 78. The junction formed by the connector 78 and a cooperating connector (not shown) leading to a monitor for determining the parameters under investigation by the sensors is described in U.S. Pat. No. 5,230,031.
FIG. 6 and FIG. 6D show the relative positions of the introducer 64 and the catheter 1 when the catheter is still in the tonometer (not shown). The catheter is maintained in a sterile environment in the tonometer, which is packaged in a sterile package, such as that described in U.S. patent application Ser. No. 07/888,569 (U.S. Pat. No. 5,246,109), prior to use. When the catheter is to be used it is first calibrated while being retained in the tonometer. After calibration the collar 66 and the clamp nut are loosened so that the tonometer may be removed and the second tube be extended forward to envelop the distal portion of the catheter at the position illustrated in FIG. 6A. Sterile liquid introduced through obturator 71 and line 70 flushes out tonometer solution, removes air bubbles, maintains a sterile environment around the catheter and prevents contamination from atmospheric contaminants. Also, immediately prior to use heparinized saline solution is introduced to prevent clot formation. The apparatus may be locked in this position with the catheter retracted inside the introducer by tightening the clamp nut 72. When the catheter is to be introduced into a patient's blood vessel, the nozzle is placed within a cannula, previously inserted into the blood vessel, the clamp nut is loosened and the second tube is retracted back into the first tube thereby allowing the catheter to be threaded into the cannula. When the removable stop 75 is placed at a predetermined distance along the second tube and the catheter is inserted to a depth so that the stop rests against the distal end of the first tube as shown in FIG. 6B this is typically the proper depth for the radial artery position. When the stop is removed and the second tube is retracted so that the end of the clamp nut comes to rest against the distal end of the first tube, as shown in FIG. 6C, this is typically the femoral artery position. Alternatively, since patients are of different sizes the operator may determine the proper depth of insertion by using the gradations 74 on the second tube. When the catheter is inserted to the proper position, the clamp nut is tightened, thus locking the catheter, second tube and first tube and the apparatus is strapped to the arm or leg of the patient with the aid of the wings 67, 68.
In summary, the apparatus comprising the combination of catheter and introducer facilitates the introduction of the catheter into a blood vessel through a cannula whilst minimizing contamination by physical contact. The main parts of the introducer are:
(i) The extension tube (second tube) which allows the fixing of various clinical tubing fittings to be distal from the site of cannulation.
(ii) The Y junction compression fitting which allows reversible hermetic sealing around the catheter. The Y junction also allows the attachment of pressure lines, blood sampling lines and other accessories.
(iii) The concentric first and second tubes allow the advancement of the catheter by sliding of the second tube attached to the catheter relative to the first whilst keeping the catheter completely covered. Thus, when in the advanced position, no portion of the catheter in contact with body fluids can have been contaminated by physical contact with outside contaminants.
The multi-parameter catheter included in the apparatus has the various features and components described above. In particular, at least a part of the outer wall or sheath of the catheter is defined by a biphasic membrane according to the invention, the space surrounding the sensors within the catheter is filled with a hydrophilic medium, and the cells in the optical fiber sensors are filled with an indicator-containing medium. Filling of the micropores of the biphasic membrane and the other filling operations described herein are achieved with the aid of a vacuum rig apparatus as illustrated in FIGS. 7 and 8 of the drawings.
The apparatus illustrated in FIG. 7 comprises a first vessel 80, which in the preferred embodiment is a spherical bottle, made of glass or transparent plastic, having an exit port 81 enabling it to be connected to a second vessel 82. In the preferred embodiment the connection between the first vessel and the second vessel is a tubular conduit 83 having an arc-shaped profile and tapered ends 84, 85 which make a fluid-tight connection with a female port 81 in the first vessel and a female port 86 in the second vessel, respectively. The second vessel is a hollow tube having a proximal end terminating in the port 86 and a distal end 87 which is integral with a "U" shaped tube 88 having an open distal end 89 which projects into a space defined by a third vessel 90. In the preferred embodiment the third vessel is substantially tubular in shape and the tube is perpendicular to the tubular second vessel. The tubular third vessel is a reservoir for liquid and when the apparatus is used as described hereinafter liquid 91 is introduced into the reservoir up to a level just below the distal end 89 of the "U" tube. The distal end of the reservoir has a first port 92 which acts as a drain and is sealed with a liquid-tight plug 93 when the apparatus is in use. The reservoir also has a second port 94 through which it is connected to a fourth vessel 95. The fourth vessel has a first port 96 which acts as an additional drain and may be sealed with a plug 97; a second port 98 through which liquid is introduced into the apparatus and which is sealed with a plug 99; and a third port 100 which is adapted to be connected to a vacuum line 101 through which a vacuum may be pulled on the apparatus. A hook shaped trap 102 is located at the lower end of the entry port 98. This trap prevents liquid from being sucked back into the vacuum line when a vacuum is pulled. A tubular conduit 103 connects the second vessel to the fourth vessel and acts as a vent when a vacuum is pulled on the apparatus.
The vacuum rig apparatus is used for introducing a liquid into a space defined by a shaped article. Shaped articles of particular interest herein, all of which may be filled with the desired liquid medium by the vacuum rig apparatus of the invention, are the optical fiber pH and pCO 2 sensors (where the liquid medium is a solution of gel and indicator), and the electrochemical pO 2 sensor (where the liquid medium is an electrolyte solution), used in the multi-parameter catheter described herein, the catheter itself and the biphasic membrane of the invention. For the purpose of illustration the operation of the vacuum rig apparatus will be described with reference to microporous hollow fiber (MPHF) used to form the biphasic membrane of the invention. A bundle of MPHF, for example microporous polyethylene having a porosity of 40%, is placed in the first vessel 80 of the apparatus in the upright position as shown in FIG. 7 so that the distal end 2 containing the micropores to be filled with liquid extend into and are suspended within the second vessel 82, as shown in FIG. 8. The ports 92 and 96 are sealed with plugs 93 and 97, respectively, and the reservoir 90 is filled, through port 98, with the desired liquid 91, for example, a gelling solution containing polyacrylamide, indicator and gelling agent, up to a level just below the distal end 89 of the "U" tube. The entry port 98 is then sealed with plug 99 and, with the apparatus still in the upright position, a vacuum is pulled on the apparatus through line 101 and port 100. The vacuum is maintained until the liquid is fully degassed and the micropores in the MPHF are evacuated, usually about 15-20 minutes. The rig is then tilted to the position shown in FIG. 8 whereupon the liquid 91 from the reservoir enters the distal end 89 of the "U" tube and runs down the tube 88 and into the second vessel 82 where it surrounds the fibers and diffuses into the evacuated micropores, thus providing a hydrophilic infrastructure within a hydrophobic matrix.
The following working example illustrates in more detail the preparation of hydrophilic gel filled porous fibers according to the invention.
EXAMPLE
(A) Vacuum Filling Ethanol/Water
A 60/40 v/v solution of ethanol and ultra high purity (UHP) water was prepared by mixing 60 ml. of ethanol and 40 ml. of water in a 100 ml. measuring cylinder. The solution was poured into the reservoir of a vacuum rig as described herein. A bundle of sensors (about 50), bound with polytetrafluoroethylene (PTFE)tape was loaded into the vacuum rig so that the distal ends of the sensors extended into the sensor-holding vessel 82. The entry port of the vacuum rig was sealed and the vacuum line connected to the vacuum port. The vacuum line was opened, while ensuring that the needle valve inlet was closed, and a vacuum was pulled until a vacuum of 0-10 mbar was reached. The vacuum was held on the solution until the liquid was fully degassed, about 15-20 minutes.
The vacuum rig was then tilted (FIG. 8) so that the solution poured into the sensor-holding vessel and fully covered the complete length of the MPHF on all the sensors plus about 10-20 min. above the butt-joint between the tubing 6 and the sheath 2 (FIG. 1). The rig was then returned to the upright position and the sensors immersed in ethanol for a further 5 minutes. The vacuum line was closed, the inlet valve fully opened and the interior of the rig allowed to reach atmospheric pressure.
(B) Gelling Solution (Diffusion Fill)
Because of the hazardous nature of the solution used in this step the handler should wear protective clothing, including gloves, goggles and face mask.
A 250 ml. flask is filled with a gelling solution comprising 15% w/w acrylamide monomer, 2.65% w/w methylene bisacrylamide cross-linking agent, 7.65% w/w ammonium persulphate initiator, and 12% w/w indicator (for example, phenol red) in a phosphate buffered aqueous solution adjusted to pH 3 with hydrochloric acid, and the solution was stirred with an ultrasonic stirrer. The sensors, treated in step (A) above were now transferred from the vacuum rig. Since the ethanol/water mixture is volatile and the sensors can dry out very quickly, the sensors were transferred to a vessel containing UHP water. The sensors were immersed in the gelling solution such that the full length of the MPHF was submerged, and the sensors were held in the gelling solution for two hours.
(C) Set Gel
Again protective clothing should be worn by the handler.
A heated water bath was switched on until the temperature reached 40°±1° C., the temperature being checked with a thermometer. A number of test tubes were filled with a solution of TMED (N,N,N',N'-tetramethylethylene diamine), and placed in holders in the water bath.
The sensors were removed individually from the gelling solution and each sensor was dipped into an individual test tube containing TMED solution for four minutes, ensuring that the MPHF portion of the sensor was fully immersed in the TMED solution. Each of the sensors was then removed from the TMED solution and transferred directly into an acid conditioning solution of about 17% w/v sodium dihydrogen orthophosphate at a pH of 4.5 and held in the solution for about 30 minutes. When all of the gelled portions of the sensors were a solid yellow color they were ready for transfer to the cure bath.
(D) Curing
The sensors were removed individually from the acid conditioning solution. A hanger was attached to the tip of each sensor and the sensors were racked with the MPHF portion fully submerged in the tonemeter solution, i.e. a 12 mMolar solution of sodium carbonate and sodium sulphate. During this operation the circulation system is run constantly to ensure that there was no microbiological contamination of the cure bath.
The temperature of the cure bath was set to 50°-55° C. and maintained at this temperature for not less than 2 hours.
The cured sensor was mounted in a tonometer which was then sealed in a package where it was sterilized and stored until required for use.
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A vacuum rig apparatus for introducing a liquid into a space defined by a shaped article, which apparatus comprises a series of interconnected vessels attached through a port to a vacuum line, wherein one of the vessels is adapted to hold the shaped article and the apparatus is tiltable about a point midway along the vessel so that liquid from a reservoir flows into the vessel to surround the shaped article and fill the space therein when a vacuum is applied to the apparatus.
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FIELD OF THE INVENTION AND RELATED ART STATEMENT
1. Field of the Invention
The present invention relates generally to a circuit breaker, and more particularly to a circuit breaker having an over-current tripping device.
2. Description of the Related Art
A circuit breaker in the prior art is disclosed in the Japanese Published Unexamined Patent Application Sho 60-32211 or Japanese Utility Model Sho 55-29931, for example. In these prior art, when an over-current flows in distribution lines of an electric power by accident of an electrical equipment which is connected to the distribution lines or the distribution lines itself, the over-current is detected by a current transformer which is mounted on the distribution lines. The detected signal of the current transformer is inputted to a processing circuit, and when the current exceeds a predetermined value of the current, an output signal is issued and is applied to a timer circuit. The timer circuit outputs an output signal after a predetermined time period. The output signal is applied to the gate of a thyristor, and an over-current tripping coil is excited by turn-ON of the thyristor, and thereby contacts of the circuit breaker are opened.
A circuit block diagram of a conventional general circuit breaker is shown in FIG.4. Referring to FIG.4, a current transformer 21 is mounted on an alternating current distribution line 11. An output signal of the current transformer 21 is rectified by a full-wave rectifier 30. A voltage regulating circuit 500 is connected across a positive output terminal 31 and a negative output terminal 32 of the rectifier 30 through a resistor 40 for detecting a current flowing the voltage regulating circuit 500. The voltage regulating circuit 500 is provided with a center terminal 5c which is grounded. Therefore, the voltage regulating circuit 500 outputs a positive voltage +V at a terminal 5a and a negative voltage -V at a terminal 5d with respect to the center terminal 5c. A differential amplifier 60 is composed of an operational amplifier 63 and resistors 64, 65, 66 and 67. A voltage across both the terminals of the resistor 40 is converted to a signal which is produced across the ground and the output terminal of the differential amplifier 60.
A timer circuit 70 is composed of a long time-lag tripping circuit 170, a peak value converting circuit 210, an effective value converting circuit 211, a short time-lag tripping circuit 220 and an instant tripping circuit 230. The output signal of the operational amplifier 63 is applied to the peak value converting circuit 210, the effective value converting circuit 211 and the instant tripping circuit 230. The output signal of the peak value converting circuit 210 is applied to the short time-lag tripping circuit 220, and the output signal of the effective value converting circuit 211 is applied to the long time-lag tripping circuit 170. The respective output terminals of the long time-lag tripping circuit 170, the short time-lag tripping circuit 220 and the instant tripping circuit 230 are connected together, and are coupled to a terminal 70a of a switch 55. The other terminal of the switch 55 is coupled to a coil of a switch 120. A tripping coil 80 is coupled to a coil of a switch terminal 31 of the rectifier 30 and one terminal 80A of the switch 120. The other terminal 80b of the switch 120 is coupled to the negative terminal 5d of the voltage regulating circuit 500. A shut-off mechanism 100 is driven by the tripping coil 80 which is activated by a close of the switch 120, and a contact 201 is opened by the shut-off mechanism 100.
An operation inhibiting circuit 50 is connected across the positive output terminal 5a and the negative output terminal 5d of the voltage regulating circuit 500, when the output voltage of the voltage regulating circuit 500 is lower than a predetermined value, the switch 55 is opened to inhibit operation of the shut-off mechanism 100.
A voltage which is induced in the current transformer 21 by an alternating current flowing through the distribution line 11 is rectified by the full wave rectifier 30. The output current of the rectifier 30 flows the voltage regulating circuit 500 and the resistor 40, and a constant DC voltage is issued from the voltage regulating circuit 500. Thus, the full wave rectified current corresponding to the current 1a of the distribution line 11 flows through the voltage regulating circuit 500 and the resistor 40. The positive voltage +V and the negative voltage -V are issued from the respective terminals 5a and 5d of the voltage regulating circuit 40 with respect to the grounded center terminal 5c. The electric power for the differential amplifier 60 is supplied by the voltage regulating circuit 500, and a voltage Vin across both the terminals of the resistor 40 are inputted to the respective input terminals of the differential amplifier 60 through the resistors 64 and 66, respectively.
The output signal of the differential amplifier 60 is applied to the instant tripping circuit 230 and also to the short time-lag tripping circuit 220 through the peak value converting circuit 210, and also to the effective value converting circuit 211.
An output voltage Ex of the effective value converting circuit 211 is applied to the long time-lag tripping circuit 170.
In the above-mentioned timer circuit 70, as shown in FIG. 6, the instant tripping circuit 230 activates the shutoff mechanism 100 with a short time lag of 20 msec when a large current which is larger than a current I H flows. The short time-lag tripping circuit 220 activates the shutoff mechanism 100 with a time lag of 100 msec when a current which is lower than the current I H but is higher than a current I M flows. The long time-lag tripping circuit 170 activates the shutoff mechanism 100 with a time lag of 100 sec when a current I L which is lower than the current I M but is higher than a rated current I L flows.
FIG. 5 is the circuit block diagram of the long time-lag tripping circuit 170 in the conventional circuit breaker. The output voltage Ex is inputted to a comparator 35 of the long time-lag tripping circuit 170. When the output voltage Ex is equal to a reference voltage Ey of a reference voltage setting circuit 37, a switch 36 which is operated by the output of the comparator 35 is opened, and electric charge into a capacitor 38 is started.
For instance, when the current flowing the distribution line 11 is 200 amperes, if the output voltage Ex is 0.5 V, the reference voltage Ey of the reference voltage setting circuit 37 is set to 0.6 V. Then, when the output voltage Ex of the effective value converting circuit reaches 0.6 V, the switch 36 of the comparator 35 is opened, and electric charge to the capacitor 38 is started. In the above mentioned case, the current flowing the distribution lines is estimated to 240 amperes.
On the other hand, the output voltage Ex is applied to a voltage-current converting circuit 44 and is converted to a current Ib.
In the voltage-current converting circuit 44, the current Ib is in proportion to the square of the output voltage Ex. For example, when the voltage Ex is 0.5 V, the current Ib is 1 μA, and when the voltage Ex is 1 V, the current Ib becomes 4 μA.
When the voltage e1 of the capacitor 38 exceeds a reference voltage E2 of a reference voltage setting circuit 42 for setting a time period in long time-lag tripping operation, an output signal is issued from the comparator 41. The time period is 100 sec when the current I of the distribution line 11 is two times of the rated current, for example as shown in FIG.6.
For example, in case that a current of 80% of the rated current flows continuously, the circuit breaker is not tripped. However, the wires of the distribution lines are heated by the current. In the above mentioned state, when the current is increased to two times of the rated current, as mentioned above, the circuit breaker is tripped after 100 seconds. Whereas, the wires are considerably heated by the continuous current of 80% of the rated current, and the wires are further heated in high temperature by the current of two times of the rated current during the additional time period of 100 seconds. Thus the wire is liable to be damaged by unexpected temperature rise.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a circuit breaker wherein a time lag in a long time-lag tripping operation of a tripping device is shortened in case that a current which is substantially equal to a rated current flows during a long time period prior to increase of the current above the rated current.
The circuit breaker in accordance with the present invention comprises:
a first switch for opening or closing an distribution line,
a current transformer for detecting a current of the distribution line,
a rectifier for rectifying a detected signal of the current transformer,
a voltage regulating circuit connected across a positive terminal and a negative terminal of the rectifier,
detecting means for detecting an output current of the rectifier,
a differential amplifier for amplifying the output of the detecting means,
a timer circuit for producing a time lag corresponding to the current of the distribution line,
a second switch to be operated by an output of the timer circuit,
a tripping coil connected to the second switch for driving the first switch, wherein
the timer circuit comprises:
a first reference voltage setting circuit for issuing a first reference voltage for setting the rated current,
a second reference voltage setting circuit for issuing a second reference voltage which is lower than the first reference voltage,
a first comparator for comparing an output voltage of the differential amplifier with the first reference voltage,
a second comparator for comparing the output voltage of the differential amplifier with the second reference voltage,
a voltage-current convertor for converting the output voltage of the differential amplifier to a current,
a capacitor for charging the current from the voltage-current convertor,
a current leaking means connected in parallel to the capacitor,
a third switch connected in parallel to the capacitor and to be opened by an output of the first comparator,
a fourth switch connected in parallel to the capacitor and to be opened by an output of the second capacitor,
a third reference voltage setting circuit for issuing a reference voltage for setting a time lag in a long time-lag tripping operation, and
a third comparator for comparing a terminal voltage of the capacitor with the reference voltage of the reference voltage setting circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit block diagram of an embodiment of a circuit breaker in accordance with the present invention;
FIG. 2 is a circuit block diagram of a long timelag tripping circuit in the embodiment;
FIG. 3 is a graph showing operation of the embodiment;
FIG. 4 is the circuit block diagram of the conventional circuit breaker;
FIG. 5 is the circuit block diagram of the long time-lag tripping circuit in the conventional circuit breaker;
FIG. 6 is the graph showing operation of the conventional circuit breaker.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A block diagram of an embodiment of the circuit breaker in accordance with the present invention is shown in FIG. 1. Referring to FIG. 1, a current transformer 21 is mounted on an alternating current distribution line 11. An output signal of the current transformer 21 is rectified by a full-wave rectifier 30. A voltage regulating circuit 500 is connected across a positive output terminal 31 and a negative output terminal 32 of the rectifier 30 through a resistor 40 for detecting a current flowing the voltage regulating circuit 500. The voltage regulating circuit 500 is provided with a center terminal 5c, which is grounded. Therefore, the voltage regulating circuit 500 outputs a positive voltage +V at a terminal 5a and a negative voltage -V at a terminal 5d with respect to the center terminal 5c. A differential amplifier 60 is composed of an operational amplifier 63 and resistors 64, 65, 66 and 67. A voltage across both the terminals of the resistor 40 is converted to a signal which is produced across the ground and the output terminal of the differential amplifier 60.
A timer circuit 77 is composed of a long time-lag tripping circuit 270, a peak value converting circuit 210, an effective value converting circuit 211, a short time-lag tripping circuit 220 and an instant tripping circuit 230. The output signal of the operational amplifier 63 is applied to the peak value converting circuit 210, the effective value converting circuit 211 and the instant tripping circuit 230. The output signal of the peak value converting circuit 210 is applied to the short time-lag tripping circuit 220, and the output signal of the effective value converting circuit 211 is applied to the long time-lag tripping circuit 270. The respective output terminals of the long time-lag tripping circuit 270, the short time-lag tripping circuit 220 and the instant tripping circuit 230 are connected together, and are coupled to a terminal 70a of a switch 55. The other terminal of the switch 55 is coupled to a coil of a switch 120. A tripping coil 80 is connected between the positive terminal 31 of the rectifier 30 and one terminal 80A of a switch 120. The other terminal 80b of the switch 120 is coupled to the negative terminal 5d of the voltage regulating circuit 500. A shut-off mechanism 100 is driven by the tripping coil 80 which is activated by close of the switch 120, and a contact 201 is opened by the shut-off mechanism 100.
An operation inhibiting circuit 50 is connected across the positive output terminal 5a and the negative output terminal 5d of the voltage regulating circuit 500. When the output voltage of the voltage regulating circuit 500 is lower than a predetermined value, the switch 55 is opened to inhibit operation of the shut-off mechanism 100.
FIG. 2 is a circuit block diagram of the long time-lag tripping circuit 270. Referring to FIG. 2, an output voltage Ex of the effective value converting circuit 211 is applied to the respective input terminals 35c and 35d of comparators 35a and 35b. A switch 36a is operated by the output of the comparator 35a, and a switch 36b is operated by the comparator 36b. A reference voltage Ey of a reference voltage setting circuit 37a is applied to an input terminal 35e of the comparator 35a. A voltage Ez which is a voltage made by diving by the reference voltage Ey 48 and 49, is applied to an input terminal 35f of the comparator 35b. Each one terminal of the switches 36a and 36b is connected together and is coupled to an input terminal E1 of the comparator 41. The other terminal of the switch 36a is grounded through a bias power source 45. The bias power source 45 is composed of a battery 47 which is grounded at its negative terminal and an oppositely poled diode 46 which is coupled by its cathode to the positive terminal of the battery 47. The other terminal of the switch 36b is grounded. A capacitor 38 and a resistor 39 are connected between the input terminal E1 of the comparator 41 and the ground. A voltage-current conversion circuit 44 is connected between the input terminal 35c of the comparator 35a and the input terminal E1 of the comparator 41. A reference voltage power source 42 for setting a long time-lag is coupled to an input terminal E2 of the comparator 41.
Operation of the embodiment is elucidated hereafter.
A voltage which in induced in the current transformer 21 by an alternating current flowing the distribution line 11 is rectified by the full wave rectifier 30. The output current of the rectifier 30 flows the voltage regulating circuit 500 and the resistor 40, and a constant DC voltage is issued from the voltage regulating circuit 500. Thus, the full wave rectified current corresponding to the current 1a of the distribution line 11 flows the voltage regulating circuit 500 and the resistor 40. The positive voltage +V and the negative -V are issued from the respective terminals 5a and 5d of the voltage regulating circuit 40 with respect to the grounded center terminal 5c. The electric power for the differential amplifier 60 is supplied by the voltage regulating circuit 500, and a voltage Vin across both the terminals of the resistor 40 are inputted to the respective input terminals of the differential amplifier 60 through the resistors 64 and 66, respectively. A gain A of the differential amplifier 60 is given by
A=Vout/Vin=Rout/Rin.
The output signal of the differential amplifier 60 is applied to the instant tripping circuit 230, and through the peak value converting circuit 210 to the short time-lag tripping circuit 220 and through the effective value converting circuit 211 to the long time-lag tripping circuit 270.
FIG. 3 is a graph showing operation of the circuit breaker in accordance with the present invention. Referring to FIG. 3, when a current flowing in the distribution line 11 exceeds the current I H , a voltage Vin corresponding to the current of the voltage regulating circuit 500 increases and an output voltage Vout of the differential amplifier 60 significantly increases. Consequently, the instant tripping circuit 230 is immediately activated, and the switch 120 is closed within 20 milliseconds. The current range which is larger than the current I H is named "current range of instant tripping".
When the current of the distribution line 11 is smaller than the current I H but is larger than a current I M as shown in FIG. 3, the short time-lag tripping circuit 220 is activated, and the switch 120 is closed within 100 milliseconds. The current range between the current I M and I H is "current range of short time-lag tripping".
When the current of the distribution line 11 is smaller than the current I M but is larger than a current I L shown in FIG. 3, the long time-lag tripping circuit 270 is activated as shown hereafter. Referring to FIG. 2, the output voltage Ex from the effective value converting circuit 211 is inputted to the comparators 35a and 35b. When the output voltage Ex reaches a reference voltage Ez of the reference voltage setting circuit 37b, the switch 36b is opened by the output of the comparator 35b. Then, the capacitor 38 is charged by the output current Ib of the voltage-current converting circuit 44. In this time, since the switch 36a is closed, the terminal voltage E1 of the capacitor 38 does not exceed the voltage E1 of the power source circuit 45. Since the voltage E1 of the power source circuit 45 is lower than the output voltage E2 of the reference voltage setting circuit 42, the output terminal of the comparator 41 remains low level.
When the current Ia of the distribution line 11 is 200 A which is a rated current of the circuit breaker, for example, the output voltage Ex of the effective value converting circuit 211 is set to 0.5 V, and the reference voltage Ey and Ez of the reference voltage setting circuit 37a and 37b are set to 0.6 V and 0.4 V, respectively. In this case, when the output voltage Ex of the effective value converting circuit 211 reaches 0.4 V, the switch 36b of the comparator 35b is opened and charge to the capacitor 38 is started.
In the above-mentioned condition, when the current Ia flowing the distribution line 11 is 160 A, which is 80% of the rated current 200 A, the distribution line 11 is gradually heated. However, the distribution line 11 is not damaged by heating since the current is lower than the rated current of the circuit breaker. The output voltage Ex is 0.4 V (80% of 0.5 V), and the switch 36b of the comparator 35b is opened. Therefore, the capacitor 38 is charged by the output of the voltage-current converting circuit 44.
Subsequently, when the current Ia of the distribution line 11 is increased to 400 A which is double as large as the rated current 200 A, for instance, the output voltage Ex of the effective value converting circuit 211 becomes 1 V, and exceeds the reference voltages Ey and Ez. Consequently, the switch 36a is opened. The output current Ib of the voltage-current converting circuit 44 flows in the capacitor 38 because of open state of the switch 36a. Since the capacitor 38 is already charged until the voltage E1 of the power source circuit 45, the capacitor 38 is further charged so that the terminal voltage of the capacitor 38 reaches the output voltage Ex from the voltage E1. When the voltage E1 of the capacitor 38 exceeds the voltage E2 of the reference voltage setting circuit 42, the output signal of the comparator 41 turns to high level, and the switch 120 is closed. Consequently, the tripping coil 80 is activated, and the contact 201 is opened through the shut-off mechanism 100.
As mentioned above, when the current of the distribution line 11 is increased to 200% of the rated current from 80% of the rated current, the voltage E1 of the capacitor 38 is already retained to the voltage E1 which is equal to the voltage of the power source circuit 45. Therefore, a time period wherein the voltage E1 exceeds the reference voltage E2 of the reference voltage setting circuit 42 is shortened as a result, the time-lag in the long time-lag tripping operation is also shortened as shown by a dotted line in the graph of FIG. 3.
On the other hand, when the current 1a of the distribution line 11 is rapidly increased to a valuse twice as large as the rated current from a comparatively low current, both the switches 36a and 36b are simultaneously opened. Since the voltage E1 of the capacitor 38 is retained to zero until opening of the switches 36a and 36b, a long charging time is required. Therefore, the circuit breaker is operated by the long time-lag operation which is similar to the operation as shown in FIG. 6 as shown by the solid line in the graph of FIG. 3. In above-mentioned case, the distribution line 11 is not heated by the low current prior to increase of the current. On the contrary, in case that the current of 80% of the rated current has been flowing before increase of a double of the rated current and hence the distribution line 11 has been considerably heated, the time lag of the long time-lag tripping operation is shortened in comparison with state which is not heated, and thereby unexpected trouble is effectively prevented.
In case that the current 1a of the distribution line 11 is comparatively small such as 10%-20% of the rated current, the output voltage of the voltage regulating circuit 500 is low and operation of the timer circuit 70 is liable to be unstable. In order to prevent mal-operation of the timer circuit 77 in the abovementioned state, the switch 55 of the operation inhibiting circuit 50 is opened, and thereby closing operation of the switch 120 is blocked.
In the embodiment, the effective value converting circuit 211 can be replaced by the peak value converting circuit 210.
Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been changed in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.
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When a current of a distribution line is increased to about two times of a rated current of a circuit breaker, the circuit breaker is operated to open the distribution line with a comparatively long time lag such as 100 seconds by a long time-lag tripping circuit of the circuit breaker, on the other hand, in case that a current of 80-90% of the rated current have continuously flowed before the current is increased as mentioned above, the time lag which is set in the long time-lag tripping circuit is shortened.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. Provisional Application Ser. No. 60/215,146, filed Jun. 30, 2000, for a Combination Lampshade, and claims the benefit of said filing date.
BACKGROUND OF THE INVENTION
This invention relates to lampshades generally, and, more specifically, to a combination lampshade device primarily directed to providing interchangeable outwardly appearing lampshades over a base which may be independently utilized as a lampshade, without the use of any affixing means, beyond the shape of the individual elements.
The concept of a cover for an existing lampshade, either for protection, or for varying the outward appearance, only, is generally known. U.S. Pat. No. 5,746,506, issued to Dunbar, provides a removable lampshade cover which is secured to an existing lampshade, at its top and/or at its bottom, by elastic band fastening means. U.S. Pat. No. 5,662,412, to Glendmyer, discloses a removable cover for an existing lampshade by utilization of VELCRO fasteners affixed both to the cover material and to the existing lampshade. U.S. Pat. No. 5,532,912, to Bendit, discloses a lampshade dressing kit for receiving fabric over an existing lampshade frame by clamping strips to the upper and lower rims of the existing lampshade frame where said strips are utilized to hold the added material in place. U.S. Pat. No. 5,211,474, to Leitner et al, discloses a do-it-yourself lampshade kit for preparing and affixing material to a base lampshade utilizing adhesive means. U.S. Pat. No. 5,193,902, issued to Hyland et al, discloses a universal foldable lampshade of pleated material which may be reduced in circumference at its upper end and held in place primarily by a strip of double-sided adhesive tape. U.S. Pat. No. 4,731,715, to Anderson, discloses a lampshade cover utilizing a drawstring and/or elastic band to hold the same in place. U.S. Pat. No. 4,646,216, to Chong et al, discloses a pleated lampshade cover and method which utilizes one or more circumferential elastic bands to hold the cover in position.
While all of the referenced prior art relates, in some respects, to covering an existing lampshade, or lampshade frame, with different material, or a different “appearance,” all of said applications are directed to separate and distinct fastening “means” such as adhesive, drawstring, or elastic bands to hold the cover in place. Further, the applications shown in the prior art, as an example, the Glendmyer patent, require a modification to the base shade, which renders the base shade unacceptable for use standing alone without the cover, or, as in the case of the Dunbar patent, or the Anderson patent, utilize fastening means beyond the shape of the cover, which present, when in place, a different shape, or overall “feel” than that provided by the base standing alone. The referenced prior art is not directed to a combination lampshade assembly which may be used as a complete assembly combination or may be utilized in conjunction with existing lampshade assemblies, which allows, at the user's option, the existing base shade to be utilized alone without visible modification or in combination with one or more outer shells, which do not change the outer shape of the overall assembly from the outer shape of the base lampshade assembly, and which one or more outer shells may be held in place solely by the “fit” of each successive outer shade over the base shade, or any succeeding outer shade, by the force of gravity, and without additional fastening means.
Neither does the known prior art address the present invention's feature of providing a combination outer shade utilizing one or more translucent inner shades, and one or more outer shades having “cut-out” areas, thereby providing the ability to provide, not only a variety of external surface appearances, but, within those appearances, an infinite variety of visible lighted designs and a virtual unlimited supply of translucent colors.
Accordingly, a need exists for a combination lampshade which does not require any modification to the base lampshade assembly which would prevent it from being utilized alone, in an aesthetically pleasing manner, and which will permit interchangeable variations of the outer appearance of the entire assembly while maintaining the appearance of a single shade.
Further, a need additionally exists for a lampshade assembly, as mentioned above, in which the external component or cover may be interchanged without application and/or adjustment of any other fastening means, and which can be immediately returned to the original application without removal of any fastening means.
SUMMARY OF THE INVENTION
This invention is directed to the provision of a lampshade assembly device, which is essentially a combination lampshade having a base lampshade element, which is, essentially, a standard lampshade, which combination lampshade does not require any modification to the base lampshade assembly which would prevent it from being utilized alone. It is further directed to a combination lampshade which, in combination with the base lampshade, provides a lampshade cover element, which may be of one, or two, separate elements, which lampshade cover or shade may be included in any number of interchangeable variations. The invention, in its base form, constitutes a combination lampshade which includes a standard base lampshade having a uniform outer surface, an upper opening and a lower opening, with a differentiation in surface area of the openings whereas the diameter of the base lampshade increases from top to bottom.
An outer lampshade cover, of a rigid material sufficient to allow it to stand alone, is provided. The cover rigid cover lampshade may be provided in multiple units, all interchangeable. It is configured so that it is slightly larger than the base lampshade, but uniformly configured to match it so that it may be placed over the base lampshade and, in such placement, the outer diameter of the base lampshade and the inner diameter of the cover lampshade correspond in a male-female relationship with the top opening and bottom opening of the base lampshade and of the cover lampshade defining areas, for the top and the bottom, which are substantially in the same horizontal plane, with the outer surface of the base lampshade contacting the inner surface of the cover lampshade across their respective general surface areas. The cover lampshade is held in place, gravitationally, by such contact and, when properly configured, covers the outer surface of the base lampshade.
According to a further feature of the invention, the base lampshade may be constructed of an opaque, transparent or translucent material and the cover lampshade may be configured so as to provide cut-out areas whereby light from the lamp, through the opaque base shade, may project defined images through the outer cover lampshade, when the inner shade is transparent or translucent.
According to a further feature of the invention, the cover lampshade element may be provided in two parts, with each part being available in multiple interchangeable variations. In this feature of the invention, an inner shade element is provided which may be of rigid or non-rigid material, with its shape generally conforming to the outer shape of the base lampshade. This inner cover shade is constructed of opaque, translucent or transparent material. A second or outer cover shade is provided having cut-out areas in it so that, when used in combination with a translucent or transparent base shade material, light from the lamp may be projected through the base shade, further through the inner shade, and through cut-outs on the rigid outer shade, to provide lighted defined images of varying shapes and/or colors or levels of intensity depending upon the combination of inner and outer shades chosen. For example, a translucent inner shade may be of different degrees of translucency, or of different colors. One outer shade may be used with a variety of inner shades, or, the variations may be combined in any desired combination. As stated, the lamp can always be utilized with simply a single outer shade, or with only the base lampshade assembly.
The outer shade element may, of course, be constructed of an opaque material without cut-outs, simply to provide a variation in that manner as well.
The base lampshade element, in all applications, provides a means, normally standard for such lampshades, for affixing the same to the lamp itself.
The above and additional features of the invention may be considered and will become apparent in conjunction with the drawings, in particular, and the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an assembled combination lampshade, according to the invention, as mounted on a lamp;
FIG. 2 is an exploded perspective view of a combination lampshade showing a standard base shade assembly and one interchangeable outer shade, as mounted on a lamp;
FIG. 3 is a perspective view of an interchangeable cover shade defining cut-out areas;
FIG. 4 is a perspective view of an embodiment of the invention, assembled, including two interchangeable cover shades utilized together, with the first outer shade of an opaque material and the second outer shade defining cut-out areas;
FIG. 5 is an exploded perspective view of the invention showing a two part outer shade used in combination with the base shade, with the first portion of the outer shade being opaque and the second portion of the outer shade defining cut-out areas;
FIG. 6 is a perspective view of a combination lampshade in the form of a four-sided truncated pyramid structure, mounted on a lamp;
FIG. 7 is a perspective view of a combination lampshade in the form of a truncated three-sided triangular combination as mounted on a lamp;
FIG. 8 is a cross-sectional view taken on line 5 — 5 of FIGS. 1 and 4;
FIG. 9 is a side view of a combination lampshade comprising a disassembled base shade assembly and outer shade combination;
FIG. 10 is a top view of a combination lampshade comprising a disassembled base shade assembly and outer shade combination;
FIG. 11 is a bottom view of a combination lampshade comprising a disassembled base shade assembly and outer shade combination;
FIG. 12 is a side view of a combination lampshade, disassembled, showing a base shade assembly, a first opaque outer shade and a second outer shade defining cut-out areas;
FIG. 13 is a top view of a combination lampshade, disassembled, showing a base shade assembly, a first opaque outer shade and a second outer shade defining cut-out areas;
FIG. 14 is a bottom view of a combination lampshade, disassembled, showing a base shade assembly, a first opaque outer shade and a second outer shade defining cut-out areas;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Throughout the following detailed description, like numerals are used to reference the same element of the present invention, although the same may be shown in more than one figure thereof.
The invention combination lampshade 10 , broadly considered, includes a base lampshade assembly 11 , which is essentially a standard lampshade, with an upper opening 12 and a lower opening 13 , the exterior surface 14 of base lampshade assembly is a generally uniform closed surface 14 running between the upper opening 12 and lower opening 13 , with a corresponding closed inner surface 15 . The upper opening 12 defines a surface area A and the lower opening 13 defines a surface area B. The uniform closed surface 14 runs from the upper opening 12 to the lower opening 13 . Area B is larger than area A, thence the diameter C of the closed uniform surface 14 surrounding area B is greater than the diameter D of the closed uniform surface 14 surrounding area A. The closed uniform surface 14 presents a truncated outer appearance which runs generally uniformly at an increasing diameter from the upper opening 12 to the lower opening 13 .
The base assembly 11 is affixed to a lamp 20 by a standard bracket 16 or other means as may be generally known and available.
The invention 10 further includes a rigid outer lampshade assembly 30 . In the preferred embodiment of the invention, this rigid outer lampshade assembly 30 is constructed of material of sufficient rigidly to allow it to stand alone and maintain its structural integrity.
The rigid outer lampshade assembly 30 , similarly to the base lampshade assembly 11 , has an upper opening 31 and a lower opening 32 , defining, respectively, surface areas AA and BB. Assembly 30 , likewise, has a closed exterior surface 33 encircling and running between the upper opening 31 and lower opening 32 . Surface area AA is smaller than surface area BB in substantially the same ratio as surface area A is smaller than surface area B in base lampshade assembly 11 . The rigid outer lampshade assembly 30 also has a closed interior surface 34 which corresponds to the closed exterior or outer surface 33 . Both interior surface 34 and exterior surface 33 are truncated in the same manner as the outer surface 14 and inner surface 15 of base lampshade assembly 11 .
The outer lampshade assembly 30 is sized and configured so that the outer closed surface 14 of base assembly 11 fits removably within the closed interior surface 34 of the rigid outer lampshade assembly 30 in a male-female relationship as shown in FIGS. 1 and 2. When in place in said male-female relationship, the closed outer surface 14 of base assembly 11 and the closed inner surface 34 of outer assembly 30 contact each across the areas of their respective surfaces, the respective surface areas A and AA are substantially within the same horizontal plane, the respective surface areas B and BB are substantially within the same horizontal plan, and the outer assembly 30 completely covers the closed outer surface of the base assembly 11 , with the outer assembly 30 being held in place, gravitationally, by circumferential contact with the base assembly 11 .
The rigid outer lampshade assembly 30 may be provided in one or more interchangeable assemblies constructed of different materials or colors, and may be opaque or translucent.
In the preferred embodiment of the invention, the base lampshade assembly 11 may also function alone as a lampshade if the outer assembly 30 is removed.
In a variation of the preferred embodiment, the closed outer surface 14 of the base lampshade assembly 11 may be alternately constructed of opaque, translucent, or transparent material. The outer closed surface 33 and corresponding inner closed surface 34 may also define one or more apertures 35 in the shape of desired designs. When the outer surface 14 of the base assembly 11 is opaque, and outer assembly 30 is in place, the design of the aperture(s) 35 may be apparent because of color or material variation. When said outer surface 14 is transparent, said aperture(s) 35 may be visible by radiated light or lack of color, and when said outer surface 14 is translucent, said aperture(s) 35 may be visible because of any combination of these factors. When outer assembly 30 is provided in interchangeable units, as previously described, such units may vary on their outer surface 33 and inner surface 34 in color, material, and/or in design, number and combination of apertures 35 provided.
In another variation of the preferred embodiment, the outer shade assembly 30 may be provided where such assembly 30 has a first cover shade or member 40 having an upper opening 41 a lower opening 42 , an upper defined surface area AAA and lower defined surface area BBB, as well as a closed outer surface 43 and corresponding closed inner surface 44 , in the manner as generally described above for a single unit outer lampshade assembly 30 . In addition, such first cover shade or member 40 may not necessarily be of rigid material, but is sized and configured to fit over the outer surface 14 of the base assembly 11 in a male-female relationship. Said member 40 may be of opaque, transparent or translucent material, and may be of varying degrees of translucence and/or varying colors.
In this variation of the preferred embodiment, as demonstrated in FIGS. 5, 12 , 13 and 14 , assembly 30 has a second cover shade or member 50 , generally comprised of the same elements as such assembly 30 has in the initial preferred embodiment. Said second member 50 is constructed of a rigid material sufficient to allow it to stand alone and maintain its structural integrity; it has an upper opening 51 , and lower opening 52 , defining surface areas corresponding substantially to surface areas AA and BB in the initial preferred embodiment. Second member 50 likewise, has a closed exterior surface 53 encircling and running between the upper opening 51 and lower opening 52 . The defined surface area corresponding to AA is smaller than that corresponding to BB in substantially the same ratio as surface area A is smaller than surface area B in the base assembly 11 . Second member 50 also has a closed interior surface 54 which corresponds to the closed exterior or outer surface 53 . Both interior surface 54 and outer surface 53 are truncated in the same manner as provided for base lampshade assembly 11 , and first member 40 .
First member 40 and second member 50 are respectively sized and configured so that the outer closed outer surface 14 of base assembly 11 fits removably within the interior or inner surface 44 of the first element 40 in a male-female relationship as shown in FIGS. 5 and 12, and the closed outer surface 43 of first element 40 fits removably within the closed interior surface 54 of the second element 50 , in a like male-female relationship, as likewise shown in said FIGS. 5 and 12. When in place, the closed surface 14 and closed inner surface 44 , the closed outer surface 43 and closed inner surface 54 , respectively, contact each other across their respective surfaces, with the respective surface areas A, AA and AAA substantially within the same horizontal plane, and the respective surface areas B, BB and BBB substantially within the same horizontal plane. The second element 50 completely covers first element 40 and base assembly 11 , with the outer assembly 30 , in its entirety, being held in place, gravitationally, by circumferential contact with the base assembly 11 , by the first member 40 , and like circumferential contact between first member 40 and second member 50 . In this variation of the preferred embodiment, the second element 50 of assembly 30 may be constructed alternatively of opaque or translucent material and may contain apertures 35 of type and combination as previously described for outer assembly 30 . Any combination of one or more each interchangeable first elements 40 and second elements 50 may be provided.
WHEREAS, a preferred embodiment of the invention has been illustrated and described in detail, it will be apparent that further and various changes may be made in the disclosed embodiment without departing from the spirit of the invention.
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The invention is directed to a combination lampshade assembly. The assembly consists of a base lampshade with a closed outer surface, with an upper opening and lower opening and a generally uniform closed surface area between them. The base lampshade assembly has no visible connecting devices or means which would differentiate it from the outward appearance of a standard lampshade. The base lampshade may be of opaque, transparent or translucent material. A rigid outer lampshade assembly is configured to fit over the standard lampshade base assembly and is held in place gravitationally by contact between the base assembly and the outer assembly. The outer assembly may be in two interchangeable pieces, with an inner sheath, and an outer cover with cut-out designs on its surface.
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BACKGROUND
1. Field of Invention
This invention relates to the methods and apparatus for remotely controlling a telephone's ringer and providing alternative signaling methods.
2. Description of Prior Art
When a telephone call comes in, the telephone rings. This ring takes place if the intended recipient of the call is asleep or otherwise doesn't want to be interrupted by a telephone call. Many telephones have the ability to control their ringer. There are often two controls for the ringer, volume and on/off Some telephones have their own distinctive ring and some allow the owner to select the style of ring. This allows differentiation between multiple lines that may ring to a single telephone.
Some telephones use other techniques to signal an incoming telephone call. One such technique is the telephone that blinks a light instead of causing an audible ring.
There have been some improvements that allow a specific telephone to be silent for a specific period of time. But there is no system for silencing a plurality of telephone ringers from one location. Nor is there any system currently for directing the telephone's ring to an alternate (inaudible) signaling device upon demand.
The present invention adds remote control capabilities to the basic ringer control. The ability to remotely silence a telephone's ringer will allow someone to prevent another from being awakened or disturbed by an incoming call.
The following existing patents seem to most closely relate to the present invention:
U.S. Pat. No. 4,893,329 describes a centralized telephone ring deferral device which operates between a telephone line and all telephones connected to the line. The device is not dedicated to any specific telephone, but governs operation of all telephones. The device can even be implemented in a telephone company's central office. While this patent generally covers the subject matter of the present invention, it is a more complicated and expensive implementation that requires keeping the time of day, adding a deferral period to the time of day and transmitting a message to a caller telling when the deferral period will end. Further, it does not allow the user to individually select which telephones should ring and which should not. Unlike the present invention, the device disclosed in this patent actually answers the telephone call.
U.S. Pat. No. 4,405,839 describes a timed telephone ring silencer device that is connected to a telephone and silences that telephone's ringer for a specific period of time.
U.S. Pat. No. 4,409,439 describes a device that uses its own chimes to signal incoming telephone calls. The device may also be set to silence the first few rings or all rings after a specified number. It may be silenced during specified intervals.
U.S. Pat. No. 4,459,435 describes a device that uses its own annunciator to announce incoming telephone calls as well as an ability to silence the ringer for a given number of rings.
U.S. Pat. No. 4,480,154 describes a device that automatically silences a telephone's ringer, based on a 24 hour clock and/or an alarm clock. The device is not remotely controlled and does not employ the use of alternative signaling devices.
U.S. Pat. No. 5,191,607 describes a device that mutes the ring on a telephone connected to a control console center capable of receiving at least two telephone calls. This allows operators to concentrate on the telephone call they are on, without the disturbance of additional telephone lines ringing. The device provides for an automatic switch back to normal operation after a set period of time, or upon call termination.
U.S. Pat. No. 5,388,150 describes an automatic incoming telephone call identification and disposition system which uses a database of telephone numbers and a calendar to route incoming calls based on who is calling and when they are calling. While the system includes ring suppress, it requires significant hardware and databases to implement. The disclosed device works on a call-by-call basis and is used to ring different extensions (or answering machines or faxes) based on the identity of the caller and the information contained in the disposition calendar. The device requires replacement of existing telephone equipment or rewiring of existing premise wiring.
There is currently no system for remotely controlling a telephone's ringer or signaling other remote devices that a telephone call is coming in.
OBJECTS AND ADVANTAGES
The present invention relates generally to controlling a telephone's ringer from a remote location, signaling alternative alert means, and providing alternative means for signaling certain events. The controller may silence the telephone's ringer, cause the telephone to ring in a distinctive manner, and/or cause another device to ring or otherwise signal an alert. The advantage is that the ringers on existing telephones may be silenced remotely, thereby preventing telephonic interruptions. Additionally, alternative ringing means can be provided to signal incoming telephone calls or other events. The present invention can easily be inserted by simply plugging it in between an existing telephone and the telephone line. The present invention may be operated remotely, adding to its usefulness and will not affect the operation of existing telephone answering devices or other devices connected to a telephone line.
The present invention is particularly useful when someone has fallen asleep near a telephone or is having a meeting near a telephone. From a remote location, the ringer on that telephone may be silenced so that if a call comes in the telephone will not ring.
In addition, it would be very useful to suppress the ringer on one or more telephones and cause some other device to signal an incoming call.
Further, the present invention can be used to cause the telephone, or other devices, to ring in a distinctive manner to signal some other event, such as a doorbell press.
The present invention may signal other remote devices, such as a local pager, which may be equipped with audible and/or inaudible signaling modes. This replaces the "broadcast" ring with a "narrowcast" ring. This allows a person to move around an office and have that person's private phone line alert him/her to an incoming phone call. After notification of an incoming call, the person may go to the closest phone and direct the call to ring at that extension in order to get the call. The ability to silence the ringer on all phones and use an alternate signaling device in a silent mode allows a person to move freely around a house without fear of missing calls or having those calls wake others who are sleeping.
The ability to remotely shut off audible ringers and to signal other devices provides a completely silent notification of an incoming call. This signaling method can be used for other events, such as a doorbell press.
SUMMARY OF THE INVENTION
It is the intention of the present invention to provide a simple method of silencing the ring of specific extension telephone(s) from a remote location. The present invention can use existing telephone equipment and wiring.
As an enhancement to the basic system, it is also the intention of the present invention to allow for the ringing of a telephone with a distinctive ring to signal an event other than an incoming telephone call.
As a further enhancement to the basic system the present invention can signal an alternate signaling device, providing audible and/or inaudible signaling.
In accordance with these intentions, the present invention would be inserted between the telephone and the telephone line. It would block the ring of the telephone when in the "Ring Block" mode and allow the telephone to ring normally in the "Ring Pass-Through" mode. The present invention may be switched between the "Ring Block" and "Ring Pass-Through" modes remotely or locally. In either ring modes, the present invention can also signal other devices, or not, depending on its mode. It can also generate distinct rings to signal other events.
A more complete understanding of the invention may be obtained from the detailed description that follows taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Features, aspects and advantages of the invention will be more fully understood when considered with respect to the following detailed description, appended claims and accompanying drawings where:
FIG. 1 is a system overview of the present invention;
FIG. 2 is a diagrammatic representation of the components of the present invention;
FIG. 3 is an usage logic diagram of the present invention;
FIG. 4 is a connection diagram showing the connection of the present invention;
FIG. 5 is an operation logic diagram of the present invention;
FIG. 6 is a diagrammatic representation of the connection of an alternate ring generator;
FIG. 7 is a connection diagram showing connections of multiple ring controllers.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following preferred embodiment is an example of the application of the present invention, but is not intended to limit in any way the claims made herein.
In the preferred embodiment, there will be one or more Ring Controllers (FIG. 1. item 110). A standard telephone line (FIG. 1, item 120) is connected to the Ring Controller and to any other Alternate Signaling Devices (FIG. 1, item 150). The Ring Controller is connected to a standard telephone (FIG. 1, item 100) and any other Alternate Ring Devices (FIG. 1, item 130). Alternate Events (FIG. 1, item 140) may also signal the Ring Controller. The Telephone Line may also signal Alternate Signaling Devices (FIG. 1, item 150).
The system is comprised of one major component (FIG. 2, item 220) in addition to other components normally required to operate a telephone system (telephone (FIG. 2, item 230) and telephone line (FIG. 2, item 210)) and optional other components (alternate ring transmitter (FIG. 2, item 240), alternate ring receiver (FIG. 2, item 250), remote control device(s) (FIG. 2, item 260) and alternate event(s) (FIG. 2, item 270)). The Ring Controller (FIG. 2, item 220) is comprised of several logical components (FIG. 2, items 221-228). When the Ring Controller (FIG. 2, item 220) senses off hook (FIG. 2, item 221) or DTMF signals (FIG. 2, item 222) from any telephone connected to the telephone line that the Ring Controller is connected to, that information is passed to the Ring Controller on/off logic (FIG. 2, item 227). Additionally, a portable remote control (FIG. 2, item 260) can provide commands to the Ring Controller on/off logic via the Remote Control Code Detect (FIG. 2, item 226). The Ring Controller on/off logic controls the Ring Blocker (FIG. 2, item 224) which takes input from the telephone line Ring detect (FIG. 2, item 223) and Distinctive Ring Generator (FIG. 2, item 228) and channels it to the Local Telephone Device (FIG. 2, item 230) or blocks the ring. The Ring Blocker also controls an optional Mode Indicator (FIG. 2, item 225) which indicates the mode the Ring Controller is in.
FIG. 3 shows the usage logic diagram indicating which actions are taken depending on which mode the Ring Controller is in. The event Telephone Ring (FIG. 3, item 310) is passed to the Ring Mode (FIG. 3, item 330) and to the optional Alternate Device Mode (FIG. 3, item 340). If the Ring Mode is set to Pass-Through (FIG. 3, item 332), then the telephone rings (FIG. 3, item 334). If the Ring Mode is set to Ring Block (FIG. 3, item 336), then the telephone doesn't ring (FIG. 3, item 338). If the Alternate Device Mode is set to None (FIG. 3, item 342), there is No Other Action taken (FIG. 3, item 344). If the Alternate Device Mode is set to Signal Other Device (FIG. 3, item 346), then an Alternate Device is Alerted (FIG. 3, item 348). An Other Event (FIG. 3, item 320) passing through an Alternate Ring Generator (FIG. 3, item 325), if necessary, may also trigger the Ring Mode and Alternate Device Mode actions.
Prior to application of the Ring Controller, each telephone is connected directly to a telephone line, or other means serving the purpose of a telephone line (cable television, microwave transmission, satellite transmission, radio frequency transmission or other means, (FIG. 4, items 410 and 420). After application of the Ring Controller (FIG. 4, item 430), the telephone line (FIG. 4, item 420), passes through the Ring Controller prior to being connected to the telephone (FIG. 4, item 410). Similar insertions of the Ring Controller can be made on all extension telephones that are to be controlled (FIG. 7, items 720, 750 and 780) but not on those not to be controlled or other devices not to be controlled (such as a telephone answering device (FIG. 7, item 790)). Telephones not directly connected to the Ring Controller (FIG. 7, item 795) may still control other telephones via their Ring Controllers.
To activate the Ring Controller, a person lifts the handset from any extension phone, presses any button on the keypad and then replaces the handset (FIG. 5, item 510). (Alternatively, the Ring Block command can be issued by a portable remote control device or a local pager base station.) This sets all Ring Controllers into their Ring Block mode (FIG. 5, item 520). The Ring Controller connected to that extension phone (if there is one) would make an audible tone to indicate that all Ring Controllers have been set to the Ring Block mode and all Ring Controllers could turn on a light or otherwise silently signal that they are in the Ring Block mode. To turn on the ringer on any phone equipped with the Ring Controller, the person lifts and resets the handset of that phone (FIG. 5, item 550). This does not effect any other extension telephone. It merely places that Ring Controller in the Ring Pass-Through mode, makes an audible tone and turns off the Ring Block mode indicator light (or other silent signal).
Each Ring Controller would have its own automatic reset circuitry and would automatically return that Ring Controller to the Ring Pass-Through mode (FIG. 5, item 540) after the expiration of a given time (FIG. 5, item 530). No audible tone would be generated to signal that the Ring Controller has returned to the Ring Pass-Through mode, but the light or other silent indicator would be turned off.
Upon sensing its unique address, that Ring Controller would take the requested action (either return to the Ring Pass-Through mode (FIG. 5, item 580) or go into the Ring Block mode (FIG. 5, item 560)). Upon sensing an "all reset" command, all Ring Controllers would return to the Ring Pass-Through mode (FIG. 5, item 570).
An alternate signaling device may also be incorporated into the system by inserting that device (or its transmitter) between the telephone line and the Ring Controller. A local pager base station can be inserted as the Alternate Signaling Device (FIG. 6, item 660) to alert a pager(s) that a phone call is coming in. The pager can be set in either the audible or inaudible (vibrator) mode, depending on the wishes of the wearer.
Alternate events (FIG. 6, item 630), such as a doorbell push, can be routed into an alternate ring generator (FIG. 6, item 620) for ringing telephones (FIG. 6, item 690) with a distinctive ring. Distinctive alerts can be issued to signal that the alternate event has occurred. The alternate signaling device (FIG. 6, item 660) can also be used to signal an alternate ringer (FIG. 6, item 650) upon the occurrence of a ring on a Telephone Line (FIG. 6, item 680) or an alternate event (FIG. 6, item 630).
The alternate ring generator (FIG. 6, item 620) can be used to control the Ring Controller(s) (FIG. 6, item 670) by sending a control instruction when the alternate signaling device is activated causing the Ring Controller(s) to go into the Ring Block mode. Upon its deactivation, the alternate ring generator 620 can send a control instruction to the Ring Controller(s) restoring them to the Ring Pass-Through mode.
Multiple Ring Controllers can be installed in a single residence or office. Each telephone to be controlled (FIG. 7, items 710, 740, 770) is connected to its own Ring Controller (FIG. 7, items 720, 750, 780) and then to a Telephone Line (FIG. 7, item 730). Since a Telephone Answering Device (FIG. 7, item 790) will probably not be subjected to the ring suppression of the Ring Controller, it is connected directly to the telephone line. Similarly, if there is a telephone(s) (FIG. 7, item 795) that is not to be subjected to the ring suppression of the Ring Controller, it is connected directly to the telephone line.
The present invention is not to be limited to the specific embodiments which are shown or described above and which are merely illustrative. Various and numerous other arrangements may be devised by one skilled in the art without departing from the spirit and scope of this invention.
The scope of the invention is defined in the following claims.
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A device (FIG. 1, item 110), which may be remotely controlled, inserted between a telephone (FIG. 1, item 100) and a telephone line (FIG. 1, item 120) that controls the telephone's ringer to silence it or not, to cause it to ring in a different manner to signal an event other than an incoming telephone call (FIG. 1, item 140), and/or to signal another device (FIG. 1, item 130) to indicate an incoming call.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of provisional patent application No. 61/176,152, filed on May 7, 2009, which is incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC AND AN INCORPORATION BY REFERENCE OF THE MATERIAL ON THE COMPACT DISC
[0003] None.
BACKGROUND OF THE INVENTION
[0004] (1) Field of the Invention
[0005] This invention relates generally to the production of fuels, chemicals, and soil amendments from biomass by means of thermolysis. More specifically, the invention relates to the acid-catalyzed thermolysis of algae.
[0006] (2) Description of the Related Art
[0007] The depletion of economically accessible petroleum and impending climate changes that follow from the accumulation of anthropogenic carbon dioxide in the atmosphere and the oceans, have motivated the search for carbon-neutral fuels that can be produced economically and domestically. Biomass, which derives its energy content from sunlight, and whose carbon comes from already oxidized carbon, promises to be a renewable feedstock from which to produce liquid fuels that can substitute for fuels derived currently from petroleum.
[0008] Aquatic microalgae are widely distributed organisms that accumulate carbon dioxide and nutrients from their environment into a material, algal biomass, which can be harvested (separated from the water). Algal biomass grows more rapidly than do terrestrial plants, as evidenced by much higher areal productivities. It has long been thought that algae, which can grow very rapidly compared to terrestrial plants, might be a suitable source of biomass from which to produce liquid fuels.
[0009] A much discussed route to convert algal biomass into liquid fuels is to extract lipids (plant fats), and to convert them into either biodiesel through transesterification with a light alcohol, or to hydrotreat the lipids to make what is termed “green” diesel. This route (oil extraction) leaves behind a large amount of protein and carbohydrate. In principle, that material can be employed as an animal feed, but comparison of the flows of mass to the fuel market with those to the feed market suggest that the feed market would be rapidly saturated once algae were converted routinely to renewable fuel by that process, generating a disposal problem rather than an economic opportunity. Moreover, each of those processes typically convert only a small (and, to date, uneconomic) fraction of the heating value of the algae into the heating value of the produced fuels—either because the target fraction (e.g. the lipids) is present at low concentration in the algae, or because the conversion process itself is not energy efficient, or both.
[0010] A second route, steam reforming, produces synthesis gas that can be converted, for example, by the Fischer Tropsch reaction, into fuel range hydrocarbons. However, this route requires an investment in energy (both the steam reforming reaction and the Fischer-Tropsch reactions are typically carried out at high pressure), and is not very carbon efficient because some of the input carbon is diverted back to carbon dioxide or light hydrocarbons, which are frequently disposed by flaring.
[0011] A third route, hydrothermal processing, produces a high yield of liquid hydrocarbon products, but also a large quantity of hydrocarbon-laden water that can present a disposal cost, and a dilution of some of the desired products.
[0012] A fourth route, pyrolysis, is very general but has previously been carried out at high temperatures that exacerbate the corrosivity of the products and necessitates the use of expensive, refractory reactors.
[0013] Other processes have also been explored, but none has yet offered compelling financial economics or attractive carbon efficiencies, despite research campaigns that seem to recrudesce about every thirty years. What is needed in the art is that the algal biomass-derived feed stocks be amenable to further refining together with conventional fuel feed stocks to take advantage of the existing capital investment in petroleum refining, and to make the algal biomass-derived fuel fungible with conventional petroleum-derived fuels. It is further desirable that any solid residuum from the production of the algal biomass-derived, liquid fuel feedstock also have economic value, for example as a solid fuel or as a soil amendment where minerals and heteroatoms (e.g., N, P) can be returned to the biosphere, albeit possibly in a different venue from which they came.
BRIEF SUMMARY OF THE INVENTION
[0014] A thermolysis process for treating algal biomass, consisting substantially of dried algal cells, in which the algal biomass is heated from ambient to 460° C. in a flowing stream that contains one or more of carbon dioxide, acetic acid or other organic acids and that produces a condensable hydrocarbon product whose mass yield is greater than the dry, ash-free mass fraction of lipids in the starting algal biomass and whose higher enthalpy of combustion exceeds 25 MJ/kg plus a char, and a hydrocarbon-laden gaseous product.
[0015] Another feature of the method of the present invention is heating the previously dried, algal biomass in a readily available, waste acid gas, such as flue gas that is rich in carbon dioxide, or to intimately mix the algal biomass with a solid acid, such as a protonated, large pore zeolite, and then heating the mixture in a non-oxidizing sweep gas.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 shows a temperature profile, illustrated by a solid curve, employed in TGA/GC/MS experiments detailed in Examples 1 and 2, discussed below.
[0017] FIG. 2 shows chromatograms obtained at the sequence of the indicated sample temperatures (100° C., 290° C., 460° C.) in Example 1 during the thermolysis of a sample of algal biomass heated along the ramp shown in FIG. 1 in a flowing stream consisting of 66.7 mol % CO 2 and 33.3 mol % N 2 .
[0018] FIG. 3 shows an expanded view of a chromatogram obtained in Example 1 of the gas stream produced during the TGA/GC-MS experiment, sampled at 50° C.
[0019] FIG. 4 compares the expanded chromatograms obtained in Example 1 at 100° C. during the thermolysis of a sample of algal biomass heated along the temperature trajectory shown in FIG. 1 in a flowing stream consisting either of pure N 2 , as illustrated by a light weight curve or of 66.7 mol % CO 2 and 33.3 mol % N 2 , as illustrated by a heavy weight curve.
[0020] FIG. 5 shows chromatograms obtained in Example 1 at the indicated sequence of sample temperatures (100° C., 290° C. and 560° C.) during the thermolysis of a sample of algal biomass intimately mixed with H-ZSM-5 heated according to the temperature ramp shown in FIG. 1 in a flowing stream consisting of 66.7 mol % CO 2 and 33.3 mol % N 2 . The effluent stream from the sample was analyzed with the aid of a GC/MS at the end of the soak periods or when the temperature first reached the indicated value during the ramp periods.
[0021] FIG. 6 compares chromatograms obtained in Example 2 at 50° C. heated according to the temperature trajectory shown in FIG. 1 during the thermolysis in a flowing stream consisting of 66.7 mol % CO 2 and 33.3 mol % N 2 of a sample of algal biomass, as illustrated by a heavy curve, and another sample that had been previously, intimately mixed with H-ZSM-5, as illustrated by a light curve.
[0022] FIG. 7 is a schematic diagram of a process in which the thermolysis of algal biomass is integrated with the flue gas and waste heat from an industrial process.
[0023] FIG. 8 shows the temperature trajectory followed and the evolution of thermolysis products from the experiment described in Example 3, discussed below.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The process of the present invention includes thermolysis that can be carried out at temperatures less than 460° C. when assisted by the presence of carbon dioxide or a solid acid catalyst. In one advantageous embodiment, dry biomass consisting substantially of algal cells is contacted in the absence of additional catalysts with a stream of hot gas containing carbon dioxide. In another advantageous embodiment, dry biomass is intimately mixed with a solid acid catalyst, such as H-ZSM-5, for example, and then contacted with a stream of hot gas. The hot gas may be carbon dioxide, diluted carbon dioxide, or any other suitable hot gas. The different advantageous embodiments provide a process that evolves thermolysis products at temperatures below 100° C. and even as low as 50° C. in the presence of a solid acid catalyst. As will be seen from the examples below, the thermolysis products span compositions that are different from those seen in the pyrolysis of cellulosic biomass. The high heating value of the oily product is an advantageous result in view of much lower values typically found for pyrolysis products from cellulose (Table 1).
[0000]
TABLE 1
Comparison of the specific heating values of
petrofuels and some biofuels:
Material
HHV/MJ kg −1
Algae derived thermolysis-oil c
36
Crude petroleum
45-48
Jet fuel (minimum)
43
Refined biodiesel
38
Wood-derived py-oil
~20
[0025] Because both CO 2 -assisted and solid acid-catalyzed thermolysis of algal biomass occur at comparatively low temperatures, a process deploying either embodiment can be integrated with an industrial facility to employ heat that would otherwise be wasted and/or deoxygenated flue gas from a combustion process that would otherwise be vented. A schematic of a process flow is shown in FIG. 7 . Algae are grown in helioreactors ( 738 ), harvested continuously via flocculation ( 734 ) and pressed to remove bulk water ( 736 ). The partially dried algae are conveyed to a drying kiln ( 730 ) that can be heated using hot flue gas from the industrial partner. The temperature and flow rate of the flue gas is lowered by mixing a stream of gas from the flue ( 724 ), throttled by valve ( 728 ) and mixing the hot gas with ambient air whose inlet flow rate is controlled by the air mixing valve ( 732 ). The gases are drawn by the action of the induction fan ( 718 ) through the drying kiln and through the particle separator ( 720 ) and then a cooled in heat exchanger 722 . The now dry algae are conveyed to Kiln 710 where they are treated with hot, gas that has been deoxygenated by reaction with thermolysis char in kiln ( 714 ) and cooled in heat exchanger ( 712 ). The treated char is accumulated in storage vessel ( 716 ). The volatile products of thermolysis are condensed by passage through heat exchanger ( 702 ) and the condensibles are collected in storage vessel ( 704 ). The char is collected in vessel 706 before it is transferred to the inlet of the deoxygenation kiln ( 704 ). The hot thermolysis gas and the volatile products are transported through the kilns and heat exchangers by means of the induction fan ( 708 ), which also transports the noncondensable products of thermolysis to a flare ( 726 ) where they can be safely combusted. Because this process reuses heat from the industrial partner, there could be an allowance for the carbon dioxide that would have been produced had, instead, a carbon-based fuel been combusted to supply that heat.
Example 1
[0026] A small quantity of unwashed algal biomass, about 30 mg was placed in the pan of a thermal gravimetric balance. The gas outlet of the TGA was connected via heat-traced stainless steel tubing to a 6-port sampling valve mounted on the inlet to an HP5890 gas chromatograph equipped with a capillary column and an HP mass selective detector. Either N 2 or a mixture of 66.7 mol % CO 2 plus 33.3% N 2 was flowed through the heated chamber at about 100 ml/min. The sample was then heated according to the trajectory shown in FIG. 1 . When the sample had been heated to the temperatures indicated in FIG. 2 , constant volume samples of the effluent stream were injected into the GC/Ms through the approximately 1 ml loop attached to the 6-port sampling valve. The identity of the eluted compounds was determined by comparing the cracking pattern of the mass spectrogram of each peak against spectra drawn from the library of the instrument.
[0027] FIG. 1 depicts the weight losses in Example 1 by a sample of algae heated in either pure nitrogen, as illustrated by a short dashed curve or in a mixture consisting of 66.7% CO 2 and 33.7% N 2 , as illustrated by a long dashed curve. As indicated in FIG. 1 , the sample heated in the gas stream that contained carbon dioxide lost more weight than did the sample heated in the stream containing only dinitrogen. Buoyancy effects are suppressed in this presentation of the data because we normalized the initial weights of the samples (also measured in the reaction gases) to 100%.
[0028] The effluent stream obtained in Example 1 from the sample was analyzed with the aid of a GC/MS at the end of the soak periods or when the temperature first reached the indicated value during the ramp periods.
[0029] At the end of the first 50° C. soak period, the gas stream consisted of the compounds listed in Table 2, which eluted through the GC at times and in amounts illustrated in FIG. 3 . In particular, four compounds, which appeared at this low temperature at significantly greater abundance when the sweep gas contained CO 2 than when the sweep gas was pure N 2 , include indole, methylindole, trimethyl-bicyclo[3.1.1]heptanes, and propylcyclohexanol.
[0030] In Table 2, shown below, are compounds identified in the GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 —F30 ml/min N 2 flow gas sampled at 50° C. In FIG. 3 , the numbers labeling the peaks correspond to the compounds listed in Table 2, depicted below.
[0000]
Peak #
RT/min
Compounds
Formula
301
4.681 to 4.754
Pyrrolidinedione
C 4 H 5 NO 2
302
5.177 to 5.236
Butenoic acid, ethyl ester
C 6 H 10 O 2
303
5.604 to 5.691
Indole
C 8 H 7 N
304
6.041 to 6.119
Methyl-1H-Indole
C 9 H 9 N
305
7.806 to 7.833
TrimethylBicyclo[3.1.1]heptane,
C 10 H 18
306
7.961 to 7.997
Propylcyclohexanol
C 9 H 18 O
[0031] Identifications of the compounds represented by peaks in the chromatographic analysis of the TGA effluent for this sample at successive temperatures along the trajectory shown in FIG. 1 are presented in Tables 3-9.
[0032] Table 3, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2 flow gas sampled at 100° C. Entries in italics (Peaks 407-410) describe compounds that did not appear at 50° C. In FIG. 4 , the numbers labeling the peaks correspond to the compounds listed in Table 3, depicted below.
[0000]
Peak #
RT/min
Compounds
Formula
401
4.681 to 4.754
2,5-Pyrrolidinedione
C 4 H 5 NO 2
402
5.177 to 5.236
2-Butenoic acid, ethyl ester
C 6 H 10 O 2
403
5.604 to 5.691
Indole
C 8 H 7 N
403
6.041 to 6.119
Methyl-1H-Indole
C 9 H 9 N
405
7.806 to 7.833
trimethyl-bicyclo[3.1.1]heptane
C 10 H 18
406
7.961 to 7.997
2-Propylcyclohexanol
C 9 H 18 O
407
4.789 to 4.844
1,2,4-Triazine-3,5(2H,4H)-dione
C
3
H
3
N
3
O
2
408
6.491 to 6.532
2,4,6-trimethyl-Benzonitrile,
C
10
H
11
N
409
6.536 to 6.563
2,7-dimethyl-Indolizine,
C
10
H
11
N
410
7.955 to 8.001
3,7,11,15-Tetramethyl-2-hexadecen-1-ol
C
20
H
40
O
[0033] Table 4, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2 flow gas sampled at 200° C. Entries in italics (Peaks 11-12) describe compounds that did not appear at 100° C.
[0000]
Peak #
RT/min
Compounds
Formula
1
4.681 to 4.754
2,5-Pyrrolidinedione
C 4 H 5 NO 2
2
5.177 to 5.236
2-Butenoic acid, ethyl ester, (E)-
C 6 H 10 O 2
3
5.604 to 5.691
Indole
C 8 H 7 N
4
6.041 to 6.119
Methyl-1H-Indole
C 9 H 9 N
5
7.806 to 7.833
trimethyl-,Bicyclo[3.1.1]heptane
C 10 H 18
6
7.961 to 7.997
2-Propylcyclohexanol
C 9 H 18 O
7
4.789 to 4.844
1,2,4-Triazine-3,5(2H,4H)-dione
C 3 H 3 N 3 O 2
8
6.491 to 6.532
2,4,6-trimethyl-Benzonitrile,
C 10 H 11 N
9
6.536 to 6.563
Indolizine, 2,7-dimethyl-
C 10 H 11 N
10
7.955 to 8.001
3,7,11,15-Tetramethyl-2-
C 20 H 40 O
hexadecen-1-ol
11
5.037 to 5.142
Dodecane
C
12
H
26
12
5.933 to 5.979
1,2-dihydro-1,1,6-trimethyl
C
13
H
16
Naphthalene
[0034] Table 5, shown below, is a GC/MS chromatogram of the TGA effluent from a sample of algal biomass treated in 60 ml/min CO 2 +30 ml/min N 2 flow gas sampled at 290° C. Entries in italics (Peaks 13-15) describe compounds that did not appear at 200° C.
[0000]
Retention
Peak #
Time/min
Compounds
Formula
1
4.681 to 4.754
2,5-Pyrrolidinedione
C 4 H 5 NO 2
2
5.177 to 5.236
2-Butenoic acid, ethyl ester, (E)-
C 6 H 10 O 2
3
5.604 to 5.691
Indole
C 8 H 7 N
4
6.041 to 6.119
Methyl-1H-Indole
C 9 H 9 N
5
7.806 to 7.833
2,6,6-trimethyl-bicyclo[3.1.1]heptane,,
C 10 H 18
6
7.961 to 7.997
2-Propylcyclohexanol
C 9 H 18 O
7
4.789 to 4.844
1,2,4-Triazine-3,5(2H,4H)-dione
C 3 H 3 N 3 O 2
8
6.491 to 6.532
Benzonitrile, 2,4,6-trimethyl-
C 10 H 11 N
9
6.536 to 6.563
Indolizine, 2,7-dimethyl-
C 10 H 11 N
10
7.955 to 8.001
3,7,11,15-Tetramethyl-2-hexadecen-1-ol
C 20 H 40 O
11
5.037 to 5.142
Dodecane
C 12 H 26
12
5.933 to 5.979
Naphthalene, 1,2-dihydro-1,1,6-trimethyl
C 13 H 16
13
6.064 to 6.109
1H-Indole, 3-methyl-
C
9
H
9
N
14
6.310 to 6.341
Dodecane
C
12
H
26
15
7.274 to 7.324
Dodecane
C
12
H
26
[0035] Table 6, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2 flow gas sampled at 460° C. Entries in italics (Peaks 13, 16-38) describe compounds that did not appear at 290° C.
[0000]
Peak #
RT/min
Compounds
Formula
3
5.604 to 5.691
Indole
C 8 H 7 N
5
7.806 to 7.833
2,6,6-trimethyl-
C 10 H 18
Bicyclo[3.1.1]heptane
6
7.961 to 7.997
2-Propylcyclohexanol
C 9 H 18 O
13
6.064 to 6.109
3-methyl-1H-Indole
C 9 H 9 N
16
1.383 to 1.501
Pentane
C
5
H
12
17
2.515 to 2.606
Toluene
C
7
H
8
18
2.656 to 2.707
Cyclooctane
C
8
H
16
19
2.711 to 2.797
2,4-dimethyl-Heptane
C
9
H
20
20
4.417 to 4.485
3-methyl-Phenol,
C
7
H
8
O
21
4.517 to 4.567
Cyclododecane
C
12
H
24
22
4.567 to 4.617
Dodecane
C
12
H
26
23
5.049 to 5.085
1-methyl-2-octyl-
C
12
H
24
Cyclopropane
24
5.085 to 5.122
Dodecane
C
12
H
26
25
5.536 to 5.568
1-Tridecene
C
13
H
26
26
5.581 to 5.604
Dodecane
C
12
H
26
27
5.827 to 5.863
4-Decene
C
10
H
20
28
6.004 to 6.032
2-Tetradecene
C
14
H
28
29
6.036 to 6.063
Dodecane
C
12
H
26
30
5.931 to 5.963
Dodecane
C
12
H
26
31
6.291 to 6.314
Dodecane
C
12
H
26
32
6.314 to 6.341
Dodecane
C
12
H
26
33
6.441 to 6.468
1-Pentadecene
C
15
H
30
34
6.473 to 6.500
Dodecane
C
12
H
26
35
6.859 to 6.882
1-Hexadecene
C
16
H
32
36
6.882 to 6.909
Dodecane
C
12
H
26
37
7.273 to 7.371
Dodecane
C
12
H
26
38
7.401 to 7.428
Z-5-Nonadecene
C
19
H
38
[0036] Table 7, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2 flow gas sampled when cooled to 350° C. Entries in italics (Peaks 39-46) describe compounds that did not appear at 460° C.
[0000]
Peak #
RT/min
Compounds
Formula
3
5.621 to 5.661
Indole
C 8 H 7 N
13
6.064 to 6.109
3-methyl-1H-Indole
C 9 H 9 N
33
6.445 to 6.463
1-Pentadecene
C 15 H 30
34
6.472 to 6.495
Dodecane
C 12 H 26
35
6.850 to 6.882
1-Hexadecene
C 16 H 32
36
6.882 to 6.909
Dodecane
C 12 H 26
37
7.273 to 7.371
Dodecane
C 12 H 26
38
7.401 to 7.428
Z-5-Nonadecene
C 19 H 38
39
3.852 to 3.980
Phenol
C
6
H
6
O
40
4.303 to 4.380
2-methyl-Phenol
C
7
H
8
O
41
4.407 to 4.526
4-methyl-Phenol
C
7
H
8
O
42
4.685 to 4.730
2,5-Pyrrolidinedione
C
4
H
5
NO
2
43
4.835 to 4.885
2,4-dimethyl-Phenol
C
8
H
10
O
44
4.903 to 4.971
4-ethyl-Phenol
C
8
H
10
O
45
7.250 to 7.273
3-Heptadecene, (Z)-
C
17
H
34
46
7.396 to 7.437
3,7,11-trimethyl-1-
C
15
H
32
O
Dodecanol
Example 2
[0037] Algal biomass was comminuated with a commercial sample of H-ZSM-5 powder. A small quantity of that mixture or the algal biomass alone, about 30 mg in each case, was placed in the pan of a thermal gravimetric balance. The gas outlet of the TGA was connected via heat-traced stainless steel tubing to a 6-port sampling valve of an HP5890 gas chromatograph equipped with a capillary column and an HP mass selective detector. The samples were heated according to the temperature trajectory shown in FIG. 1 while contacted with a 90 ml/min flow of N 2 . When the sample had been heated to 50° C., 100° C., 200° C., 290° C. and 460° C., constant volume samples of the effluent stream were injected into the GC/Ms through an approximately 1 ml loop attached to the 6-port sampling valve. The full chromatograms are shown in FIG. 5 at the indicated temperatures. The identity of the eluted compounds was determined by comparing the cracking pattern of the mass spectrogram of each peak against spectra drawn from the library of the instrument.
[0038] At the end of the first 50° C. soak period, the gas stream consisted of the compounds listed in Table 8. All twelve of the peaks listed in Table 8 appeared at this low temperature only when the sample contained the acid catalyst, in this example.
[0039] In Table 8, shown below, are compounds identified in the GC/MS chromatogram shown in FIG. 6 of the TGA effluent in Example 2 from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 50° C. In FIG. 6 , the numbers labeling the peaks correspond to the compounds listed in Table 8, depicted below.
[0000]
Peak #:
RT (min)
Compounds
Formula
601
4.345 to 4.545
Phenol, 4-methyl-
C 7 H 8 O
602
4.691 to 4.754
2,5-Pyrrolidinedione
C 4 H 5 NO 2
603
4.841 to 4.895
2,4-dimethyl-Phenol
C 8 H 10 O
604
4.900 to 4.973
4-ethyl-Phenol
C 8 H 10 O
605
5.623 to 5.664
Indole
C 8 H 7 N
606
6.064 to 6.105
4-methyl-1H-Indole,
C 9 H 9 N
607
6.856 to 6.883
Cyclohexadecane
C 16 H 32
608
6.883 to 6.956
Dodecane
C 12 H 26
609
7.081 to 7.115
Dodecane
C 12 H 26
610
7.256 to 7.279
3-Heptadecene, (Z)-
C 17 H 34
611
7.279 to 7.306
Dodecane
C 12 H 26
612
7.816 to 7.838
Phytol
C 20 H 40 O
[0040] Table 9, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 100° C. Lines in italics (Peaks 13-14) describe compounds that did not appear at 50° C.
[0000]
Peak
RT (min)
Compounds
Formula
1
4.345 to 4.545
Phenol, 4-methyl-
C 7 H 8 O
2
4.691 to 4.754
2,5-Pyrrolidinedione
C 4 H 5 NO 2
3
4.841 to 4.895
Phenol, 2,4-dimethyl-
C 8 H 10 O
4
4.900 to 4.973
Phenol, 4-ethyl-
C 8 H 10 O
5
5.623 to 5.664
Indole
C 8 H 7 N
6
6.064 to 6.105
1H-Indole, 4-methyl-
C 9 H 9 N
7
6.856 to 6.883
Cyclohexadecane
C 16 H 32
8
6.883 to 6.956
Dodecane
C 12 H 26
9
7.081 to 7.115
Dodecane
C 12 H 26
10
7.256 to 7.279
3-Heptadecene, (Z)-
C 17 H 34
11
7.279 to 7.306
Dodecane
C 12 H 26
12
7.816 to 7.838
Phytol
C 20 H 40 O
13
7.392 to 7.433
1-Heptene, 2-isohexyl-
C
14
H
28
6-methyl-
14
7.956 to 7.988
3,7,11,15-Tetramethyl-2-
C
20
H
40
O
hexadecen-1-ol
[0041] Table 10, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algae and algae+zeolite samples treated in 90 ml/min of N 2 , sampled at 200° C. Lines in italics (Peaks 15-19) describe compounds that did not appear at 100° C.
[0000]
Peak
Retention
#:
Time (min)
Compounds
Formula
1
4.345 to 4.545
Phenol, 4-methyl-
C 7 H 8 O
2
4.691 to 4.754
2,5-Pyrrolidinedione
C 4 H 5 NO 2
3
4.841 to 4.895
Phenol, 2,4-dimethyl-
C 8 H 10 O
4
4.900 to 4.973
Phenol, 4-ethyl-
C 8 H 10 O
5
5.623 to 5.664
Indole
C 8 H 7 N
6
6.064 to 6.105
1H-Indole, 4-methyl-
C 9 H 9 N
7
6.856 to 6.883
Cyclohexadecane
C 16 H 32
8
6.883 to 6.956
Dodecane
C 12 H 26
9
7.081 to 7.115
Dodecane
C 12 H 26
10
7.256 to 7.279
3-Heptadecene, (Z)-
C 17 H 34
11
7.279 to 7.306
Dodecane
C 12 H 26
12
7.816 to 7.838
Phytol
C 20 H 40 O
13
7.392 to 7.433
1-Heptene, 2-isohexyl-6-methyl-
C 14 H 28
14
7.956 to 7.988
3,7,11,15-Tetramethyl-2-
C 20 H 40 O
hexadecen-1-ol
15
5.182 to 5.218
1,4:3,6-Dianhydro-.alpha.-d-
C6H8O4
glucopyranose
16
5.241 to 5.273
Phenol, 2-ethyl-6-methyl-
C9H12O
17
5.296 to 5.332
Benzene, 1-ethyl-4-methoxy-
C9H12O
18
7.606 to 7.652
1-Octadecene
C18H36
19
7.652 to 7.697
Dodecane
C
12
H
26
[0042] Table 11, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 290° C. Lines in italics (Peaks 20-29) describe compounds that did not appear at 200° C.
[0000]
Peak
RT (min)
Compounds
Formula
1
4.419 to 4.519
Phenol, 4-methyl-
C 7 H 8 O
2
4.664 to 4.746
2,5-Pyrrolidinedione
C 4 H 5 NO 2
3
4.841 to 4.895
Phenol, 2,4-dimethyl-
C 8 H 10 O
4
4.900 to 4.973
Phenol, 4-ethyl-
C 8 H 10 O
5
5.623 to 5.664
Indole
C 8 H 7 N
6
6.064 to 6.105
1H-Indole, 4-methyl-
C 9 H 9 N
8
6.883 to 6.907
Dodecane
C 12 H 26
9
7.081 to 7.115
Dodecane
C 12 H 26
10
7.256 to 7.279
3-Heptadecene, (Z)-
C 17 H 34
11
7.279 to 7.306
Dodecane
C 12 H 26
12
7.816 to 7.838
Phytol
C 20 H 40 O
13
7.392 to 7.433
1-Heptene, 2-isohexyl-6-methyl-
C 14 H 28
14
7.956 to 7.988
3,7,11,15-Tetramethyl-2-hexadecen-1-ol
C 20 H 40 O
15
5.182 to 5.218
1,4:3,6-Dianhydro-.alpha.-d-glucopyranose
C 6 H 8 O 4
16
5.237 to 5.269
Phenol, 2-ethyl-6-methyl-
C 9 H 12 O
17
5.296 to 5.332
Benzene, 1-ethyl-4-methoxy-
C 9 H 12 O
18
7.606 to 7.652
1-Octadecene
C 18 H 36
19
7.652 to 7.697
Dodecane
C 12 H 26
20
1.585 to 2.190
Acetic acid
C
2
H
4
O
2
21
2.435 to 2.499
Pyridine
C
5
H
5
N
Pyrrole
C
4
H
5
N
22
2.513 to 2.563
Toluene
C
7
H
8
23
2.631 to 2.708
Propanoic acid, 2-oxo-, methyl ester
C
4
H
6
O
3
24
4.746 to 4.773
Benzene, (2-methyl-1-propenyl)-
C
10
H
12
25
5.933 to 5.979
Naphthalene, 1,2-dihydro-1,1,6-trimethyl
C
13
H
16
26
6.493 to 6.520
Ethaneperoxoic acid, 1-cyano-1-(2-methyl
C
12
H
13
NO
3
27
6.529 to 6.570
1H-Indole, 2,5-dimethyl-
C
10
H
11
N
28
6.857 to 6.884
3-Hexadecene, (Z)-
C
16
H
32
7-Hexadecene, (Z)-
C
16
H
32
29
7.207-7.230
3-Heptadecene, (Z)-
C
17
H
34
[0043] Table 12, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algae and algae+zeolite samples treated in 90 ml/min of N 2 , sampled at 460° C. Entries in italics (Peaks 30-44) describe compounds that did not appear at 390° C.
[0000]
Peak
RT (min)
Compounds
Formula
1
4.419 to 4.519
Phenol, 4-methyl-
C 7 H 8 O
5
5.623 to 5.664
Indole
C 8 H 7 N
6
6.064 to 6.105
1H-Indole, 4-methyl-
C 9 H 9 N
10
7.253 to 7.275
3-Heptadecene, (Z)-
C17H34
11
7.279 to 7.306
Dodecane
C 12 H 26
12
7.816 to 7.838
Phytol
C 20 H 40 O
14
7.956 to 7.988
3,7,11,15-Tetramethyl-2-
C 20 H 40 O
hexadecen-1-ol
18
7.606 to 7.652
1-Octadecene
C 18 H 36
19
7.652 to 7.697
Dodecane
C 12 H 26
22
2.499 to 2.581
Toluene
C 7 H 8
30
1.908 to 1.999
Benzene
C
6
H
6
31
3.141 to 3.181
Ethylbenzene
C
8
H
10
32
3.186 to 3.241
p-Xylene
C
8
H
10
33
3.341 to 3.400
Styrene
C
8
H
8
Xylene
C
8
H
10
34
3.796 to 3.832
Benzene, 1-ethyl-2-methyl-
C
9
H
12
35
3.987 to 4.023
Benzene, 1,3,5-trimethyl-
C
9
H
12
36
4.319 to 4.355
Benzene, 1-propynyl-
C
9
H
8
37
4.787 to 4.887
Benzyl nitrile
C
8
H
7
N
38
4.901 to 4.937
Benzene, (1-methyl-2-
C
10
H
10
cyclopropen-1-yl)-
39
4.937 to 4.969
2-Methylindene
C
10
H
10
40
5.078 to 5.110
Dodecane
C
12
H
26
41
5.110 to 5.160
Naphthalene
C
10
H
8
42
5.656 to 5.711
Naphthalene, 2-methyl-
C
11
H
10
43
6.311 to 6.343
Dodecane
C
12
H
26
44
6.470 to 6.493
Dodecane
C
12
H
26
[0044] Table 13, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 350° C. Entries in italics (Peaks 46-51) described compounds that did not appear at 460° C.
[0000]
Peak
RT (min)
Compounds
Formula
1
4.419 to 4.519
Phenol, 4-methyl-
C 7 H 8 O
2
4.664 to 4.746
2,5-Pyrrolidinedione
C 4 H 5 NO 2
3
4.841 to 4.895
Phenol, 2,4-dimethyl-
C 8 H 10 O
4
4.900 to 4.973
Phenol, 4-ethyl-
C 8 H 10 O
5
5.623 to 5.664
Indole
C 8 H 7 N
6
6.064 to 6.105
1H-Indole, 4-methyl-
C 9 H 9 N
10
7.253 to 7.275
3-Heptadecene, (Z)-
C 17 H 34
11
7.279 to 7.306
Dodecane
C 12 H 26
12
7.816 to 7.838
Phytol
C 20 H 40 O
13
7.392 to 7.433
1-Heptene, 2-isohexyl-6-methyl-
C 14 H 28
14
7.956 to 7.988
3,7,11,15-Tetramethyl-2-hexadecen-1-ol
C 20 H 40 O
41
5.110 to 5.160
Naphthalene
C 10 H 8
42
5.656 to 5.711
Naphthalene, 2-methyl-
C 11 H 10
45
3.852 to 3.984
Phenol
C 6 H 6 O
46
5.184 to 5.239
1,4:3,6-Dianhydro-.alpha.-d-glucopyranos
C
6
H
8
O
4
Benzofuran, 2,3-dihydro-
C
8
H
8
O
47
5.339 to 5.398
Benzenepropanenitrile
C
9
H
9
N
48
6.126 to 6.158
Amobarbital
C
11
H
18
N
2
O
3
49
6.176 to 6.212
Pentobarbital
C
11
H
18
N
2
O
3
50
6.444 to 6.467
1-Pentadecene
C
15
H
30
51
6.472 to 6.499
Dodecane
C
12
H
26
Example 3
[0045] A preparatory scale reactor constructed from a vertical alumina tube (7 cm OD) placed in the center of an electrically heated tube furnace was loaded with approximately 200 g of algal biomass and then connected to a gas cylinder. The gas cylinder permitted the interior of the vertical alumina tube to be swept with carbon dioxide that had bubbled at ambient temperature through an aqueous solution of 5% acetic acid and then in to the reactor tube at a flow rate of 0.2 standard L/min. The effluent from the reactor was directed into a glass receiver whose outside walls were cooled in an ice bath. The temperature of the reactor tube was ramped to 400° C., as shown in FIG. 8 , and maintained at that temperature for 100 minutes, with CO 2 flowing at 45 ml/min. Approximately 100 ml of oily/waxy material was collected, from which was estimated a mass yield of 27 wt % in the oil fraction. During the heating, the nature of the effluent from the heated tube changed as indicated in Table 14.
[0046] Table 14, shown below, shows changes in the character of the effluent from the preparatory scale reactor as the reaction temperature increases.
[0000]
Marker shown
in FIG. 8
Character of the reactor effluent stream
802
Smoke starts to appear
804
Smoke stops evolving
806
Clear liquid commences to collect in the chilled receiver
vessel.
808
White smoke appears in the receiver and flows out of the
receiver
810
Yellow smoke starts to fill the receiver and a yellow wax
collects on the sides of the receiver
812
An orange liquid starts to collect in the receiver as a
dense vapor
814
A thick, dark brown tar collects in the rceiver
[0047] Analysis of the initial algal biomass showed a lipid content of 3.5%. Subsequently, the enthalpy of combustion of the oil/wax was measured in a bomb calorimeter and found to be 36 MJ/kg, with a sulfur content of 0.22%.
[0048] There are many advantages to the method of the present invention. This invention is directed at obtaining feed stocks from which to prepare liquid fuels from a renewable source, such as algal biomass that grows rapidly, with little impact on available water or food resources.
[0049] The different advantageous embodiments provide a process that converts biomass, consisting substantially of whole, dry algae cells, into an oily material that exhibits a heating value approximating that of petroleum, along with a solid carbonaceous char, a hydrocarbon-laden gas stream, and an aqueous stream that contains polar organic compounds.
[0050] In an advantageous embodiment, the algal biomass can be processed into the feedstock with a net decrease in carbon dioxide emissions, for example by using carbon dioxide and heat from an existing process that would otherwise be wasted. The process of the present invention converts a broad range of microalgae and the co-harvested micro-organisms, referred to as algal biomass, into three products: a hydrocarbon-laden gas, a carbonaceous char, a new oily material that exhibits many of the characteristics of crude petroleum, and an aqueous stream that dissolves polar compounds. The process produces significant quantities of oily product from algal biomass that does not contain high concentrations of lipids. Therefore, the process can be applied even to algal biomass that has not been selected or nurtured to generate lipids.
[0051] The thermolysis produces a range of products that commence to evolve at unexpectedly low temperatures—as low as 50° C., i.e., hundreds of degrees lower than the temperatures at which cellulosic biomass must be heated to produce pyrolysis oils. The temperature range of the thermolysis of the algal biomass is low enough that the process can be carried out using waste heat generated by other industrial processes, for example cement manufacturing. The low temperature processing confers an economic advantage and offers a possible route to so-called carbon credits for the partner industry. Moreover, the oily material derived from the algae has an unexpectedly high enthalpy of combustion—around 36 MJ/kg, which approaches the heating value of petroleum (ca. 44 MJ/kg) and is about twice as large as the heating value of pyrolysis oils derived from cellulosic biomass (ca. 20 MJ/kg).
[0052] In addition, the algal biomass-derived oily material can constitute more than 15 wt % of the original, ash-free, dry weight of the algae, even for starting material that contains less than 5 wt % lipids. Finally, the composition of the algal biomass-derived oily material suggests that it would be amenable to subsequent processing along side conventional petroleum-derived gas oil, unlike pyrolysis oils derived from cellulosic biomass. For example, the elemental analyses performed, and the heating value mentioned above, provide an inference that the oily material from the described thermolysis of algal biomass presents fewer oxygen-containing components than does cellulose-derived pyrolysis oil, along with a concentration of sulfur that is low enough to be considered for blending into low sulfur feed stocks, yet high enough to maintain the activity of conventional hydroprocessing catalysts.
[0053] These conventional hydroprocessing catalysts can be used in conventional refinery processes to hydro-upgrade the oily material, for example to remove nitrogen, metals, and oxygen heteroatoms.
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A thermolysis process for treating algal biomass, consisting substantially of dried algal cells, in which the algal biomass is heated from ambient to 460° C. in a flowing stream that contains one or more of carbon dioxide, acetic acid or other organic acids and that produces a condensable hydrocarbon product whose mass yield is greater than the dry, ash-free mass fraction of lipids in the starting algal biomass and whose higher enthalpy of combustion exceeds 25 MJ/kg plus a char, and a hydrocarbon-laden gaseous product.
In another feature, the present invention includes heating the previously dried, algal biomass in a readily available, waste acid gas, such as flue gas that is rich in carbon dioxide, or to intimately mix the algal biomass with a solid acid, such as a protonated, large pore zeolite, and then heating the mixture in a non-oxidizing sweep gas.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to commonly assigned U.S. patent applications entitled “Optical Distortion Compensation Apparatuses, Methods, and Systems”, Docket No. 981104OD and “Optical Upconverter Apparatuses, Methods, and Systems”, Docket No. 981104OU, which are filed concurrently herewith and are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] The present invention is directed generally to the transmission of information in communication systems. More particularly, the invention relates to transmitting information via optical signals in optical transmission systems and transmitters for use therein.
[0004] The development of digital technology provided resources to store and process vast amounts of information. While this development greatly increased information processing capabilities, it was soon recognized that in order to make effective use of information resources, it was necessary to interconnect and allow communication between information resources. Efficient access to information resources requires the continued development of information transmission systems to facilitate the sharing of information between resources.
[0005] The continued advances in information storage and processing technology has fueled a corresponding advance in information transmission technology. Information transmission technology is directed toward providing high speed, high capacity connections between information resources. One effort to achieve higher transmission capacities has focused on the development of optical transmission systems for use in conjunction with high speed electronic transmission systems. Optical transmission systems employ optical fiber networks to provide high capacity, low error rate transmission of information over long distances at a relatively low cost.
[0006] The transmission of information over fiber optic networks is performed by imparting the information in some manner to a lightwave carrier by varying the characteristics of the lightwave. The lightwave is launched into the optical fiber in the network to a receiver at a destination for the information. At the receiver, a photodetector is used to detect the lightwave variations and convert the information carried by the variations into electrical form.
[0007] In most optical transmission systems, the information is imparted by using the information data stream to either modulate a lightwave source to produce a modulated lightwave or to modulate the lightwave after it is emitted from the light source. The former modulation technique is known as “direct modulation”, whereas the latter is known as “external modulation”, i.e., external to the lightwave source. External modulation is more often used for higher speed transmission systems, because the high speed direct modulation of a source often causes undesirable variations in the wavelength of the source. The wavelength variations, known as chirp, can result in transmission and detection errors in an optical system.
[0008] Data streams can be modulated onto the lightwave using a number of different schemes. The two most common schemes are return to zero (RZ) and non-return to zero (NRZ). In RZ modulation, the modulation of each bit of information begins and ends at the same modulation level, i.e., zero, as shown in FIG. 1( a ). In NRZ schemes, the modulation level is not returned to a base modulation level, i.e., zero, at the end of a bit, but is directly adjusted to a level necessary to modulate the next information bit as shown in FIG. 1( b ). Other modulation schemes, such as duobinary and PSK, encode the data in a waveform, such as in FIG. 1( c ), prior to modulation onto a carrier.
[0009] In many systems, the information data stream is modulated onto the lightwave at a carrier wavelength, λ c , (FIG. 2( a )) to produce an optical signal carrying data at the carrier wavelength, similar to that shown in FIG. 2( b ). The modulation of the carrier wavelength also produces symmetric lobes, or sidebands, that broaden the overall bandwidth of the optical signal. The bandwidth of an optical signal determines how closely spaced successive optical signals can be spaced within a range of wavelengths.
[0010] Alternatively, the information can be modulated onto a wavelength proximate to the carrier wavelength using subcarrier modulation (“SCM”). SCM techniques, such as those described in U.S. Pat. Nos. 4,989,200, 5,432,632, and 5,596,436, generally produce a modulated optical signal in the form of two mirror image sidebands at wavelengths symmetrically disposed around the carrier wavelength. Generally, only one of the mirror images is required to carry the signal and the other image is a source of signal noise that also consumes wavelength bandwidth that would normally be available to carry information. Similarly, the carrier wavelength, which does not carry the information, can be a source of noise that interferes with the subcarrier signal. Modified SCM techniques have been developed to eliminate one of the mirror images and the carrier wavelength, such as described in U.S. Pat. Nos. 5,101,450 and 5,301,058.
[0011] Initially, single wavelength lightwave carriers were spatially separated by placing each carrier on a different fiber to provide space division multiplexing (“SDM”) of the information in optical systems. As the demand for capacity grew, increasing numbers of information data streams were spaced in time, or time division multiplexed (“TDM”), on the single wavelength carrier in the SDM system as a means to provide additional capacity. The continued growth in transmission capacity has spawned the transmission of multiple wavelength carriers on a single fiber using wavelength division multiplexing (“WDM”). In WDM systems, further increases in transmission capacity can be achieved not only by increasing the transmission rate of the information via each wavelength, but also by increasing the number of wavelengths, or channel count, in the system.
[0012] There are two general options for increasing the channel count in WDM systems. The first option is to widen the transmission bandwidth to add more channels at current channel spacings. The second option is to decrease the spacing between the channels to provide a greater number of channels within a given transmission bandwidth. The first option currently provides only limited benefit, because most optical systems use erbium doped fiber amplifiers (“EDFAs”) to amplify the optical signal during transmission. EDFAs have a limited bandwidth of operation and suffer from non-linear amplifier characteristics within the bandwidth. Difficulties with the second option include controlling optical sources that are closely spaced to prevent interference from wavelength drift and nonlinear interactions between the signals.
[0013] A further difficulty in WDM systems is that chromatic dispersion, which results from differences in the speed at which different wavelengths travel in optical fiber, can also degrade the optical signal. Chromatic dispersion is generally controlled in a system using one or more of three techniques. One technique to offset the dispersion of the different wavelengths in the transmission fiber through the use of optical components such as Bragg gratings or arrayed waveguides that vary the relative optical paths of the wavelengths. Another technique is intersperse different types of fibers that have opposite dispersion characteristics to that of the transmission fiber. A third technique is to attempt to offset the dispersion by prechirping the frequency or modulating the phase of the laser or lightwave in addition to modulating the data onto the lightwave. For example, see U.S. Pat. Nos. 5,555,118, 5,778,128, 5,781,673 or 5,787,211. These techniques require that additional components be added to the system and/or the use of specialty optical fiber that has to be specifically tailored to each length of transmission fiber in the system.
[0014] New fiber designs have been developed that substantially reduce the chromatic dispersion of WDM signals during transmission in the 1550 nm wavelength range. However, the decreased dispersion of the optical signal allows for increased nonlinear interaction, such as four wave mixing, to occur between the wavelengths that increases signal degradation. The effect of lower dispersion on nonlinear signal degradation becomes more pronounced at increased bit transmission rates.
[0015] The many difficulties associated with increasing the number of wavelength channels in WDM systems, as well as increasing the transmission bit rate have slowed the continued advance in communications transmission capacity. In view of these difficulties, there is a clear need for transmission techniques and systems that provide for higher capacity, longer distance optical communication systems.
BRIEF SUMMARY OF THE INVENTION
[0016] Apparatuses and methods of the present invention address the above need by providing optical communication systems that include transmitters that can provide for pluralities of information carrying wavelengths per optical transmission source, dispersion compensation, and/or nonlinear management in the system. In an embodiment, the information data stream is electrically distorted to compensate for chromatic dispersion of a lightwave/optical signal during transmission. The electrical distortion can be used to compensate for negative or positive dispersion in varying amounts depending upon the characteristics of the optical fiber in the network and to some extent offset nonlinear interactions that produce distortion of the optical signal Electrical distortion can be specifically tailored to each wavelength and bit rate used in the optical system.
[0017] Electrical dispersion compensation can be used in conjunction with other methods, such as dispersion compensating fiber or time delay components to control the level of dispersion at various points in the network. The amount of dispersion in the system can be controlled to provide a substantially predetermined value of net dispersion, e.g., zero, at the end of a link, to provide an average value over the link, and/or to minimize the absolute dispersion at any point in the link.
[0018] Electrical distortion compensation can be used with RZ, NRZ, ASK, PSK, and duobinary formats, as well as other modulation formats and baseband and subcarrier modulation techniques. In addition, the amount of electronic distortion applied to a signal can be controlled via a feedback loop from a receiver in the system to allow fine tuning of the compensation. In this manner, changes in the network performance with time can be accommodated.
[0019] In an embodiment, an information data stream is modulated on to an electrical carrier, such radio frequency (“RF”) or microwave carrier, frequency ν e . The modulated electrical carrier is upconverted on to a lightwave carrier having a wavelength λ 0 and frequency ν o produced by the optical transmission source to produce an information carrying lightwave at wavelength λ 1 and frequency ν o±e . The upconverter can be used to simultaneously upconvert a plurality of electrical frequencies onto different subcarrier lightwaves. In an embodiment, the information is modulated onto the electrical carrier in duobinary format, which provides for more narrow subcarrier bandwidths.
[0020] In an embodiment, the lightwave carrier from the optical source is split into a plurality of split lightwave carriers, each of which has one or more data streams upconverted or modulated onto it. The subcarrier lightwave optical signals generated from the split lightwave optical carriers are then recombined into the optical signal for transmission. The split lightwave carrier overcomes the problem of maintaining close wavelength spacing between multiple carriers in an operating system by employing a common optical source. The optical source providing the lightwave carrier may include one or more lasers or other optical sources.
[0021] The split lightwave carrier also provides a method of placing multiple information carrying wavelengths near the lightwave carrier without having to upconvert or modulate more than one data stream at a time onto a lightwave carrier. The upconverted lightwaves can be at wavelengths that are greater and/or less than the carrier wavelength and symmetrically or asymmetrically positioned relative to the carrier wavelength. In addition, subcarriers can be simultaneously unconverted onto the same lightwave, at least one subcarrier with a higher frequency and at least one subcarrier with a lower frequency than the carrier frequency.
[0022] The upconversion of the modulated electrical carrier can be performed using double or single sideband upconverters with or without suppression of the carrier wavelength λ o . However, the reduction or elimination of the carrier wavelength λ o and any mirror image sideband will eliminate unwanted signals which could interfere with the upconverted signal.
[0023] In an embodiment, a two sided, single sideband upconverter is provided to modulate multiple information data streams onto both longer and shorter wavelengths. In those embodiments, one upconverter can be used to upconvert data on equally or differently spaced subcarriers relative to the carrier wavelength.
[0024] In an embodiment, the polarization of adjacent lightwave carriers is controlled to decrease the nonlinear interactions of the signals. For example, adjacent wavelength signal can be orthogonally polarized to decrease the extent of four wave mixing that occurs between the signals during transmission. In addition, the wavelength spacing between neighboring upconverted signals can be selected to lessen non-linear interaction effects.
[0025] Accordingly, the present invention addresses the aforementioned problems with providing increasing the number of channels and the transmission performance of optical systems. These advantages and others will become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings wherein like members bear like reference numerals and wherein:
[0027] FIGS. 1 ( a - c ) show a typical baseband return to zero (“RZ”) and non-return to zero (“NRZ”) data signal;
[0028] FIGS. 2 ( a - c ) show the intensity versus wavelength plots for an unmodulated optical carrier, modulated carrier, and modulated subcarriers of the carrier;
[0029] FIGS. 3 - 4 show embodiments of the system of the present invention; and,
[0030] [0030]FIG. 5 shows an embodiment of a transmitter of the present invention;
[0031] FIGS. 6 ( a & b ) show transmission & reception time versus wavelength curves;
[0032] FIGS. 7 ( a - c ) show embodiments of signal distorters of the present invention
[0033] FIGS. 8 - 11 show embodiments of transmitters of the present invention
[0034] [0034]FIG. 12 shows an embodiment of transmitters of the invention;
[0035] [0035]FIG. 13 shows an embodiment of upconverters of the present invention;
[0036] FIGS. 14 - 16 show embodiments of transmitters of the present invention; and,
[0037] [0037]FIG. 17 shows a polarizing element of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The operation of optical systems 10 of the present invention will be described generally with reference to the drawings for the purpose of illustrating present embodiments only and not for purposes of limiting the same. As shown in FIG. 3, the system 10 includes an optical transmitter 12 configured to transmit information, i.e., data, etc., via one or more information carrying optical wavelengths λ 1 to an optical receiver 14 through one or more segments of optical fiber 16 j . The system 10 may also include one or more dispersion compensating components 18 and feedback controllers 20 , as well as other optical components such as optical amplifier 22 , add/drop devices 24 , and the like.
[0039] As shown in FIG. 4, the system 10 can be embodied as a network including a plurality of transmitters 12 and receivers 14 in optical communication through one or more optical switches 26 , combiners 28 , and/or distributors 30 . For example, optical and digital cross connect switches and routers, multiplexers, splitters, and demultiplexers can be employed in the system 10 . The transmitters 12 and receivers 14 can interface directly with electrical transmission systems or via electrical switches or interfaces to other optical systems that operate using the same or different wavelengths.
[0040] In an embodiment, the transmitter 12 is configured to electrically distort an electrical signal carrying data to compensate for chromatic dispersion that occurs as an optical signal Λ o carrying the data is transmitted through the optical fiber 16 1 . The electronic data signal Λ E can be in a baseband Λ B (i.e., binary, direct current), coded Λ c , or a modulated electrical carrier Λ e format.
[0041] In an embodiment of the transmitter 12 shown in FIG. 5, an electronic signal distorter 32 is configured to produce a distorted electrical signal Λ ED . A distorted optical signal Λ OD is produced using an electrical to optical converter 33 to impart the the electrical signal Λ ED onto an optical carrier lightwave Λ O . The electrical to optical conversion can be performed by upconverting the electrical signal Λ ED onto a subcarrier lightwave of an optical carrier lightwave Λ o provided by an optical source 34 . Alternatively, the conversion of electrical signal Λ ED can be performed by directly modulating the optical source 34 or externally modulating the optical carrier lightwave Λ o to produce the optical data signal at the carrier frequency. One or more signal lasers, or other appropriate optical sources as may be known in the art, can be used as the optical source 34 .
[0042] The distortion of the electronic data signal is generally in the form of an electronically induced time delay that varies as a function of the optical wavelength λ i in the optical signal Λ O . The group delay can be used to provide varying amounts of dispersion compensation for each wavelength and for each bit rate in the system 10 . The time delay characteristics can be controlled to provide linear and nonlinear, as well as positive, negative, and varying delay profiles with respect to the wavelength of the signal.
[0043] [0043]FIG. 6( a ) shows an example of a typical relative time delay at the receiver versus wavelength plot for an optical signal being transmitted with zero dispersion at a transmission time t t . Dispersion of the signal during transmission results in the different wavelengths in the signal reaching the receiver 14 at different time during a reception time interval, Δt r . The time delay in signal reception is one source of signal distortion that degrades system performance. In the present invention, distorted optical signals can be produced by introducing distortion as a group delay function of frequency, which results in the signal being transmitted over a transmission time interval Δt t . The electronic distortion is offset by dispersion in the transmission path resulting in the different frequencies reaching the receiver 14 at the same reception time t r (FIG. 6( b )), or over a reception time interval of choice (FIG. 6( c )).
[0044] One skilled in the art will appreciate that in the present invention the distortion profile of the electronic data signal can be varied as desired to control the shape of optical signal at the receiver 14 . For example, given the interrelation of chromatic dispersion and nonlinear interactions, the electrical distortion characteristics can be shaped to minimize the total distortion at the receiver 14 as opposed to minimizing only the chromatic dispersion. In addition, electronic dispersion compensation can be used in conjunction with dispersion compensating elements 18 , such as negative dispersion slope fiber, grating-based elements, etc. as are known in the art.
[0045] FIGS. 7 ( a - c ) show embodiments of signal distorter 32 of the present invention. In FIG. 7( a ),the distorter 32 includes one or more serial electrical circulators 36 having an input to an input port 1 that circulates the electrical signal to an equalizer port 2 . A resonator 38 can be connected to port 2 to serve as an all-pass transmission filter that reflects all incident power in a frequency dependent manner back to the port 2 , thereby distorting signal. The distorted electrical signal Λ ED exits an output port 3 of the circulator 36 from which it can be passed into another distortion element or exit the signal distorter 32 .
[0046] An example of resonators 38 , which are suitable for use in the present invention are impedence resonators following the general equation:
Z ( s )= sL+ 1/( sC )
L=RQ /(2π f 0 )
C= 1/(4π 2 f 0 2 L )
H ( s )=( Z ( s )− R )/( Z ( s )+ R )
D (ω)=− d/dω ( arg ( H ( jω ))),
[0047] where
Z = impedance C = capacitance D (ω) = group delay L = inductance f 0 = frequency H (s) = equalizer R = resistance Q = Q factor Transfer function
[0048] One skilled in the art will appreciate that the circulator/resonator embodiments shown in FIG. 7( a ) can be cascaded to provide desired group delay characteristics and that other networks may be used in the present invention. For example, in FIG. 7( b ), the signal distorter 32 includes one or more electrical loop couplers 35 configured to introduce the desired group delay into the electical carrier signal Λ e . Various configurations of loop couplers suitable to achieve the desired group delay can be used in the distorter 32 . FIG. 7( c ) shows an embodiment of the signal distorter 32 for distorting the baseband signal Λ B . The distorter 32 is used to separate the baseband signal λ B into I and Q components by configuring the inductors 37 and capacitors 39 to approximate the following general transfer function over the frequency range of interest:
| H I ( jω )| 2 +|H Q ( j ω)| 2 =constant.
[0049] The amount of dispersion in optical fiber 16 i is generally well documented as a function of fiber length and optical wavelength. For example, transmission fiber can typically be in the range of 15-20 ps/nm/km in the 1550 nm wavelength range. Thus, the amount of distortion necessary to produce a desired dispersion profile at a point in the optical transmission system can be calculated and adjusted as may be necessary in the system 10 . In addition, the shape of the distortion profile can be tailored to be linear or nonlinear functions of frequency to compensate for the interrelation of chromatic dispersion and nonlinear interactions.
[0050] [0050]FIG. 8 shows an embodiment of the transmitter 12 in which an electrical modulator 40 is used to modulate the baseband electric signal Λ B onto an electrical carrier at a frequency ν e from an electrical carrier source 42 . The modulator 40 can be a double balanced mixer as is known in the art. The electrical carrier signal ν e will be of the general form A(sin(ω+φ) and the baseband signal Λ E of the form V(t) resulting in an output signal of the general form kV(t)A(sin(ω+φ+φ 1 ). Thus, if the mean of the baseband signal is zero, the carrier frequency will be suppressed. Likewise, if V(t) has essentially two state ±a, the output will be in PSK format.
[0051] The electrical carrier frequency can be any suitable frequency for the data rate being transmitted, for example, RF or microwave carriers. The signal distorter 32 receives the modulated electrical carrier signal Λ e at frequency ν e and provides the distorted electrical carrier signal Λ eD . An upconverter 44 combines the distorted modulated electrical carrier at ν e with an optical lightwave carrier at a central wavelength λ o (frequency ν o ) supplied by an optical source 34 . The resulting distorted optical signal Λ OD has a frequency ν o ±ν e (“ν o±e ” ) and central wavelength at ν o±e , which is equal to c/(ν o ±ν e ), where c is the speed of light.
[0052] In embodiments shown in FIGS. 8 ( b ) and 9 , the baseband electrical signal Λ B is provided to the signal distorter 32 , which is configured to separate the signal Λ B into in-phase (“I”) and quadrature (“IQ”) components and distort the signal. The IQ components of the distorted electrical signal Λ BD are provided to an IQ modulator 46 . In the FIG. 8( b ) embodiments, the I and Q components are modulated onto the electrical carrier ν e which is upconverted onto the optical carrier ν o to produce the distorted optical signal Λ OD at the central wavelength at λ o±e . In FIG. 9 embodiments, the I and Q components are modulated onto the optical carrier having a central wavelength λ o and frequency ν o to provide the distorted optical signal Λ OD having the same central wavelength at λ o .
[0053] Conversely in FIG. 10, the baseband signal Λ B is modulated onto a portion of the electrical carrier ν e , which is passed through the signal distorter 32 to produce the distorted electrical signal Λ eD . Another portion of the electrical carrier ν e is provided as input along with the distorted electrical signal Λ eD to an IQ demodulator 48 , which separates the distorted electrical signal Λ eD into its IQ components. The IQ components of the electronic signal are provided to the IQ modulator 46 which modulates the data onto the optical carrier at the central wavelength λ o and frequency ν o provided by the optical source 34 .
[0054] In the transmitter 12 of FIG. 11, the electrical baseband signal Λ B can be encoded along with a clock signal Λ CLK using a data encoder 50 to provide an encoded data signal Λ C . The encoded data signal Λ C may be further passed through a filter 52 , such as a low pass filter, to shape the signal before being passed to the signal distorter 32 . In the transmitter 12 of FIG. 11, the IQ modulator 46 can be used to modulate the distorted electrical signal onto the electrical carrier frequency ν e . The electrical carrier can be amplified using an electrical amplifier 54 , split through electrical coupler 56 , and upconverted onto the optical carrier to produce the distorted optical signal Λ OD having its center wavelength at Λ o±e . One of the controllers 20 in the system 10 can be used to provide feedback control of the upconverter 44 , as well as the other components such as the amplifier 54 .
[0055] In embodiments of FIG. 11, the electrical coupler 56 is used to split the signal from each input path between two output paths and impart a phase shift, i.e. 90° in a 2×2 3 dB coupler, between signals on the respective output paths. The phase shift between the two output paths depends upon which input path the signal was introduced. Thus, the frequency of the resulting distorted optical signal Λ OD will be either ν o+e =ν o +ν e or ν o−e =ν o −ν e depending upon which input of the coupler 56 the electrical signals are introduced.
[0056] Data encoding techniques, such as duobinary, QPSK, and others, are useful to decrease the bandwidth of the resulting optical signal. These formats can also affect the extent of distortions that arise from signal dispersion and non-linear interaction between the signals. The detection of duobinary and other differential PSK-type signals using direct detection can be enhanced using an optical filter 58 before the receiver 14 in the optical system 10 . The optical filter 58 can be matched, i.e., comparably shaped, to the received optical spectrum of the signal, which can be controlled in the present invention using the electrical filter 52 . The optical filter 58 can be a Fabry-Perot filter or other appropriate filter as may be known in the art. The electrical filter 52 can be design to account for and match the properties of the optical filter 58 so as to minimize the bandwidth of the optical signal. It will be appreciated that the electrical filter 52 can be positioned at different locations within the transmitter 12 and modified accordingly.
[0057] In another aspect of the invention shown in FIG. 12, the transmitter 12 of the present invention can be used to simultaneously upconvert a plurality of electrical signals Λ En onto one optical carrier. A plurality of baseband electrical signals Λ B1 −Λ Bn are modulated onto a corresponding plurality on electrical carriers provided by sources 42 1 - 42 n to provide modulated electrical carriers. Signal distorters 32 can be provided to distort either the baseband signal or the modulated electrical carrier, if dispersion compensation is desired. The modulated electrical carriers are passed through the electrical coupler 56 , which divides the electrical signals between the two output paths leading to the upconverter 44 .
[0058] Numerous combinations of electrical carriers can be upconverted using the transmitter configuration of FIG. 12. For example, electrical sources 42 1 through 42 n can provide the same or different electrical carrier frequencies and depending upon how the carriers are coupled into the upconverter 44 . If more than two electrical carriers are to be unconverted using the same upconverter 44 , the additional carriers can be combined, or multiplexed, onto the appropriate coupler input. The resulting optical signal can be produced at longer or shorter wavelengths than the optical carrier wavelength λ o as previously discussed. In addition, it may also be possible to use one or more electrical subcarriers to carry additional data along with, or in lieu of, data on the electrical carrier frequency depending upon the electrical subcarrier frequency spacings.
[0059] The upconverter 44 in embodiments of FIGS. 12 and 13 is configured to upconvert the electrical signal onto a single sideband subcarrier frequency, either ν o+e or ν o−e , while suppressing the mirror image sideband subcarrier frequency. The upconverter can be operated without or with carrier wavelength suppression, although carrier suppression eliminates unwanted signals that could produce signal interference.
[0060] [0060]FIG. 14 shows an embodiment of the single side band suppressed carrier upconverter 44 suitable for use in the present invention. Other suitable single side band embodiments include those described by Olshansky in U.S. Pat. Nos. 5,101,450 and 5,301,058, which are incorporated herein by reference. As shown in FIG. 14, the optical carrier lightwave at frequency ν o is split using an optical splitter 60 into two respective optical paths, 62 1 and 62 2 , which are further split into optical paths 62 1′ and 62 1″ . The split lightwaves in optical paths 62 1 are passed between first upconverter input electrode 64 1 and a pair of ground electrodes 66 . Likewise, the split lightwaves in optical paths 62 2 are passed between second upconverter input electrode 64 2 and a pair of ground electrodes 66 . Electrical input signals v 1 and v 2 are provided to the upconverter respective input electrodes 64 1 and 64 2 via first and second inputs, 68 1 and 68 2 , respectively. The input signals v 1 and v 2 are upconverted onto the respective split lightwaves passing between the electrodes and combined in cascaded optical combiners 70 to produce the upconverted optical signal Λ o .
[0061] In an embodiment, LiNbO 3 is used to form the optical paths 62 1′ and 62 i″ , which can be used to produce linearly polarized optical signals. In addition, bias electrodes can be provided in optical paths 62 1′ and 62 1″ and/or 62 1 after passing through the input electrodes 64 1 and 64 2 . The bias electrodes can be used to trim the phase difference of the optical signals upconverted onto the subcarrier lightwaves in each path before the signals are combined.
[0062] The electrical input signals v 1 and v 2 introduced to the upconverter 44 carrying the same electrical data signal, except that the data signals have a relative phase shift between the first and second inputs, 68 1 and 68 2 , according to the relation: v 1 =v 2 ±phase shift. The sign of the phase shift determines whether the electrical data signal will be upconverted onto lightwave subcarriers that are greater or less than the carrier frequency of the lightwave. Thus, the upconverter 44 can be configured to receive and simultaneously upconvert electrical signals at the same or different electrical frequencies onto different subcarrier lightwave frequencies of the same lightwave by introducing the appropriate phase shift between the electrical input signals. For example, in embodiments of FIGS. 12 and 13, 3 dB electrical couplers 56 provide a ±90° phase shift, which allows electrical signals to be upconverted onto optical frequencies that are greater or less than the carrier frequency. One skilled in the art will appreciate that other techniques for imparting the phase shift are suitable within the scope of the invention.
[0063] The transmitter 12 shown FIG. 13 provides a configuration that can be used to symmetrically place two different optical signals around the central wavelength λ o of the optical carrier. The electrical carrier 42 supplies the electrical carrier ν e that is split into two paths, each of which is modulated using a corresponding modulator 36 1 or 36 2 with electrical baseband signals Λ B1 and Λ B2 , respectively. The two signals are passed through the electrical coupler 56 which splits and couples the signals from each of the two coupler input paths to each of the two output paths. The coupler 56 introduces a 90° phase shift into the coupled portion of the signal, shown as Λ e1 P and Λ e2 P on FIGS. 12 and 13, to produce upconverter input signals v 1 and v 2 . For example in FIG. 13, v 1 includes Λ e1 P and Λ e2 , whereas v 2 includes Λ e1 and Λ e2 P . . . The opposite phase shifts of v 1 and v 2 results in one of the two electrical signals being upconverted onto an optical subcarrier frequency ν o+e and the other electrical signal is upconverted onto the optical subcarrier frequency ν o−e , symmetric to the optical carrier frequency ν o . A skilled artisan will recognize that distorted and undistorted optical signals can be produced using the embodiment of FIG. 13 and similar embodiments.
[0064] An embodiment of the transmitter 12 , shown in FIG. 15, can be also used to provide control over proximate optical wavelengths by upconverting one or more electrical frequencies onto a plurality of optical carriers provided by the common optical source 34 . The optical carrier lightwave is split using the optical splitter 60 into split lightwaves carried on a plurality of optical paths 62 1 - 62 n . A corresponding plurality of the upconverters 44 1−n are disposed along the optical paths. A plurality of electrical baseband signal Λ B1 -Λ n are correspondingly modulated onto electrical carrier ν e1 -ν en via modulators 40 1−n . The electrical carrier signals Λ e1 -Λ en are provided to the upconverters 44 1−n and converted to subcarrier lightwave optical signals Λ o1 -Λ on at frequencies ν oe1 -ν oen and combined using an optical combiner or multiplexer 68 . When only one electrical signal is upconverted onto a split lightwave optical carrier in a path 62 1 , single or double sideband upconverters, with or without carrier suppression, can be used in the invention. Optical filters 58 can be employed to remove any undesired remnant carrier wavelengths or mirror image sidebands that are output from the particular modulator used in the transmitter 12 .
[0065] [0065]FIG. 16 shows an embodiment of the transmitter 12 that is configured to transmit four optical signals using a single optical source 34 , such as a laser 72 , emitting the optical carrier at a central wavelength λ o and frequency ν o . The baseband electrical signal Λ B1 -Λ B4 are provided as input to corresponding data encoders 50 1-4 from an electrical transmission path or from the optical receiver 14 in a short or long reach optical system. The encoded electrical signal is passed through the shaping filter 52 1-4 to respective electrical modulators 40 . Encoded electrical signals Λ C1 -Λ C2 and Λ C3 -Λ C4 are modulated onto the electrical carrier at frequency ν e1 and ν e2 , respectively. The modulated electrical signals Λ e11 -Λ e24 are passed through respective signal distorters 32 1-4 and electrical amplifiers 54 1-4 to provide amplified distorted electrical signals Λ e11D -Λ e24D . Electrical signals Λ e11D and Λ e23D can be routed through electrical coupler 56 1 to upconverter 44 1 . Likewise, electrical signals Λ e12D and Λ e24D can be routed through electrical coupler 54 2 to upconverter 44 2 . The upconverted optical signals Λ oe1D -Λ oe4D are combined in the combiner 62 prior to transmission. The interleaving of the electrical frequencies being upconverted allows for the use of optical filters 58 , with either single or double sideband modulators, to remove any unwanted sidebands or carrier wavelengths from the optical signals Λ oe1D -Λ oe4D . Transmitters 12 of the present invention can also be used to modulate data onto the lightwave carrier wavelength, in addition to upconverting electrical frequency onto the lightwave.
[0066] In the present invention, transmitters 12 configured to provide multiple optical signals, can be further configured to impart opposite polarization to pairs of optical signals being generated by upconverting the electrical signals. For example, the optical combiner 62 in embodiments such as those shown in FIGS. 15 and 16 can be a polarizing component, such as a polarizing beam splitter/combiner. The orthogonal polarization of adjacent signals will reduce or eliminate nonlinear interaction between the signals, thereby providing for more closely spaced signal wavelengths and high power signals.
[0067] Alternatively, as shown in FIG. 17, a separate polarizing element 74 can be included in the combiner 62 . An embodiment of the polarizing element 74 can includes two oppositely configured polarizing beam splitters 76 connected in series by two parallel paths 78 that produce a differential travel time between the splitters 76 . The first beam splitter 76 splits the optical signal into two equal amplitude polarization components. The second beam splitter 76 is used to recombine the two polarization components. The time differential introduced by the parallel paths 78 can be established and/or controlled to introduce differences in the polarization of the channels. For example, optical signals having sufficiently narrow bandwidths can be introduced to the first beam splitter 76 at a 45° polarization angle to allow optical signal power to propagate equally in both paths 78 . The resulting combined signals emerging from the second splitter 76 would be orthogonal if the time differential were equal to 1/(2*frequency difference between the signals). Similarly, polarization maintaining fiber can be used in lieu of the splitters 76 and parallel path 78 to introduce the time differential between the polarization components of a linearly polarized optical signal.
[0068] It will be appreciated that the present invention provides for optical systems having increasing the number of channels and the transmission performance of optical systems. Those of ordinary skill in the art will further appreciate that numerous modifications and variations that can be made to specific aspects of the present invention without departing from the scope of the present invention. It is intended that the foregoing specification and the following claims cover such modifications and variations.
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Apparatuses, methods, and systems are disclosed for controlling optical signal wavelength spacing by providing for simultaneous upconversion of a plurality of electrical signal on subcarrier frequencies of an optical carrier frequency with or without modulation of an electrical data signal onto the optical carrier frequency. The optical carrier lightwave is split into a plurality of split lightwaves upon which one or more electrical frequencies carrying information can be upconverted onto optical subcarriers of the lightwave carrier frequency. The relative spacings of the optical subcarrier lightwaves will thus be unaffected by variation in the carrier frequency. The optical subcarrier lightwaves can then be recombined to form the optical data signal carrying the plurality of information carried by the electrical frequencies.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a boiler and more particularly to a double-tube type waste heat boiler.
(2) Description of the Prior Art
Heretofore, from the standpoint of savings and recycling use of thermal energies, waste heat boilers have been put in use. With increasing interest in preservation and saving provoked by natural resources of late, there has been added the significance of waste heat boilers to cope with such circumstances and accordingly, it is so expected that the demands for large-sized, high-temperature and high-pressure designs of such waste heat boilers will become even greater hereafter. There are known general technical difficulties in the designs and constructions of waste heat boilers, among which the most common yet significant problems are such that tubings and tube sheets of the boilers subjected to hot gases are heated to high temperatures, thus inevitably resulting in the loss of strength thereof, and that stresses are produced due to differential thermal expansion from uneven temperature distribution in the metal parts organizing the boiler, i.e., a boiler drum, boiler tubes and tube sheets. In the attempt to meet such problems, as the boilers are recently designed to be larger and for use at high temperatures, reconsideration as to boiler design and construction, selection of suitable materials, increase in the material weight, troublesome and complex installation and inspection, etc., which would undoubtedly lead to increased costs and expenses in the manufacture, inspection and maintenance thereof must be considered. There are a variety of designs and constructions of waste heat boilers, among which the most typical one is such that there is provided a steel cylindrical shell or drum, having two tube sheets or plates with a plurality of openings welded or otherwise connected in an opposed relation with both ends of the boiler, and having a plurality of tubes within the boiler drum securely connected at each opening of the tube plate, respectively, wherein water is supplied from one end to the other of the boiler drum and high temperature waste gases are fed externally from one end tube plate through the plurality of tubes within the drum so as to provide heat to water within the drum and thus generate water vapor to be taken out from the other end of the drum and thereafter, the waste gases are directed outwardly from the opposite end tube plate to be discharged to a following processing step.
Now, referring to FIG. 3, a fragmentary cross-sectional view shows the conventional waste heat boiler in use and same is typically constructed in such a manner that there is a tube plate 21 connected at end of a boiler drum 20, the tube plate 21 having a plurality of tubes 22 rigidly connected thereto. There is provided a vacancy or space 24 defined by a channel 14 lined with an insulating or refractory material 15 on the exterior surface of the tube plate 21 as shown, into which high temperature waste gases are introduced and through the plurality of tubes 22 so as to be heated by transfer water within the drum 20, thereby generating water vapor. In such a construction, since the tubes 22 are subjected to high temperature gases while the boiler drum 20 is subjected to cold water, there is naturally a substantial difference in amounts of expansion between the drum 20 and the tubes 22 and as a result of such differential expansions, there occur substantial stresses at and near the connections between the plate 21 and the tubes 22 and the junction 23 between the plate 21 and the drum 20. It is noted that when there is a great difference in temperatures of the waste gases and water, or when the drum 20 or the tubes 21, having a substantial thickness, are under high water pressure, or when a waste heat boiler is of a large size, large amount of stress increases to such an extent that same eventually becomes an obstacle to the design thereof. In the case where it is of a high-pressure design, there is further stress from the increased inner pressure in addition to the stresses caused by the thermal expansion mentioned above and thus particularly resulting in further total stress at and near the junction part 23. Consequently, there is induced complexity in the configurational and structural designs of and around the junction part 23, which further makes it necessary to severely analyze possible fatigues of the material therearound, thus bringing technical difficulties in the selection of material to be used as well as in such field operations as manufacturing inspection, repairing, and so on, thus resulting in eventual increased costs and expenses of manufacture and maintenance of the boilers. Also, the tube plate 21 is designed to face high temperature gases through the refractory material 15, but still heated to a substantially high temperature on the face thereof and therefore, it would be likely lose its strength. Consequently, it is generally necessary to design the tube plate to be substantially thick, however, such a thick tube plate would necessarily bring reduced efficiency in cooling which would be effected by water behind this thick plate, thereby possibly causing the temperature of the tube plate to be further higher. For the practical design of a boiler, it is therefore essential to resolve all such technical problems.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide an improved double-tube type waste heat boiler that can solve the problems as encountered in the conventional boilers as stated above, that provides a unique construction to substantially save material to be used and is easy to assemble and install.
It is another object of the invention to provide an improved waste heat boiler having a heat exchanging section of a tubular construction that does not require a thick boiler drum. It is a further object of the invention to provide an improved waste heat boiler having less heat stresses in construction, making it possible to use relatively thin material for the design of the tube plates thereof.
A better understanding of the principles and advantages, together with the above and further objects of the present invention may be had after consideration of the detailed description of the invention with reference to the accompanying drawings, in which like parts are designated with like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing;
FIG. 1 is a longitudinal cross-sectional view showing a waste heat boiler according to the present invention;
FIGS. 2(a) through 2(e') are schematic illustrations showing, in fragmentary cross-section, a variety of junctions between the boiler tubes and the tube plate of the waste heat boiler of this invention by way of a preferred embodiment thereof; and
FIG. 3 is a cross-sectional view showing a part of a waste heat boiler of typically conventional construction.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail by way of examples, yet not restrictive thereto, in conjunction with the accompanying drawings.
Firstly, referring to FIG. 1, there is generally shown in a longitudinal cross-section the improved waste heat boiler of this invention, wherein there is provided a gas inlet channel 14 having an inlet for supply of hot gases 1, and the gas channel is lined with a refractory material 15, as necessary. More particularly, one end of each of a plurality of inner tubes or inner tube group 5 for introducing high temperature waste gases thereinto opens at the end wall surface of the gas inlet channel 14 through a tube ferrule 9, while the other end thereof opens at a tube plate 11a on the end wall of a waste gas outlet channel 16 through an annular-shaped gap therewith. There is disposed a water chamber 18 surrounded by tube plates 10, 10a and near the inlet channel 14, a plurality of outer tubes or outer tube group 6 extending in closely fitted relation through the tube plate 10. The outer tube group 6 extends through the tube plate 10a through annular gaps therewith. Also, there are a plurality of outermost tubes 7 extending around the outer circumferences of the outer tubes on the inlet channel side and through annular gaps therewith, the annular gaps opening to the water chamber 18 through the tube plate 10a. The free ends of the outermost tubes 7 and the inner tubes 5 are hermetically connected with a plurality of caps 7a of semi-torus or semi-doughnut shape, respectively. There is provided a water passage or gap between the end of each outer tube 6 on the side of the inlet channel 14 and the interior surface of each cap 7a stated above. A water inlet 3 is provided at the top of the water chamber 18. On the other hand, there is provided a gas outlet 2 in the gas outlet channel 16 and there is also provided a water vapor chamber 19 between the tube plate 11a on the end surface of the channel and another tube plate 11 disposed outwardly in parallel relationship therewith. Likewise, there is an annular gap between each of an outermost tube 8 and the inner tubes 5, respectively, each of the outermost tubes 8 extending through the opening in the tube plate 11a in dual concentric relation with each of the inner tubes 5. The above mentioned annular gap is hermetically connected with a semi-torus-shaped cap 8a between the ends of the inner tube 5 and the outermost tube 8. Also, in the tube plate 11, the inner tube 5 extends through an annular gap therearound, the circumference of the opening of the tube plate 11 through which the inner tube 5 extends being connected sealingly to the end of the outer tube 6. There is provided a water vapor outlet 4 in the water vapor chamber 19. In the inside of the water chamber 18 and the water vapor chamber 19, a plurality of stays 12 are provided tying across the both tube plates thereof together, respectively. Also in the annular gaps defined between the inner tubes 5 and the outer tubes there are inserted a plurality of spacers 17, respectively.
Now, the operation as featured in the present invention will be described as to the embodiment thereof as shown in FIG. 1. Hot waste gases fed into the inlet channel 14 through the gas inlet 1 are directed into the inner tube group 5 through the tube ferrules 9 so as to exchange heat while passing therethrough, thereafter entering into the gas outlet channel 16 to be discharged from the outlet 2. Concurrently, water is directed into the water chamber 18 through the water inlet 3 so as to fill up with the chamber, and then introduced into the annular gaps between each of the outermost tubes 7 and the outer tubes 6, passing through the semi-torus gaps between the caps 7a and the ends of the outer tubes 6 into the annular gaps between the outer tubes 6 and the inner tubes 5, where the water is heated with the hot waste gases passing through the inner tubes 5, thus becoming water vapor. Thus-produced water vapor and hot water are now directed to enter the vapor chamber 19 and eventually be discharged out of the vapor outlet 4. By virtue of such advantageous construction of this invention in that the high temperature inner tubes and the relatively low temperature outermost tube 7 are connected operatively with the caps 7a on the side of the inlet channel 14, thermal expansion from the temperature difference existing in both tubes 5 and 7 may effectively be absorbed by function of these caps 7a. On the other hand, the caps 8a on the side of the outlet channel 16 function in a like manner to absorb the thermal expansion occurring there, so that there is observed less stress to be caused by the differential thermal expansion from the temperature differences in each of the tube plates 10, 10a, 11 and 11a from that of the inner tubes 5. These caps 7a and 8a may be designed selectively in consideration of the operating temperatures of hot gases and water, and the thermal expansion involved in use, as will be described further later. While the temperature of the tube plate on the gas inlet side is observed to be so high due to contact with hot waste gases in conventional designs and constructions of waste heat boilers, the tube plate 10a according to this invention is advantageously kept away from direct contact with the hot waste gases, thus resulting in a relatively small temperature rise of the tube plate and therefore, it is not necessary to consider any substantial strength loss caused by a considerable temperature rise during the operation of the tube plate 10a in the determination of a thickness thereof.
Incidentally, according to the typical conventional design of a waste heat boiler, as typically shown in FIG. 3, it is noted that there exists the junction part between the high temperature gas tubes and the tube plate on the gas inlet side where there are low-temperature and high-pressure water and high-temperature and low-pressure gases. In contrast, according to the advantageous construction of the present invention, each of the tube plates of the boiler is effectively designed not to directly contact the hot gases and the hot gas tubes 5 and further, each of these is positively reinforced by way of stays as shown in FIG. 1. Consequently, it is now practicable to have relatively thin tube plates made available for use under high pressure and concurrently, to have an appreciable extent of savings in manpower and materials required in the manufacture of a waste heat boiler. The near end area of the tube 5 in which the hot gases pass is cooled off by constantly flowing cold water and this area is thin in thickness so that it has an efficient cooling effect. Further, it is flexible enough to absorb thermal stress existing there. Also, this area has no stagnancy since there is a relatively high flow rate of water, thus providing a cleaning effect by the stream of water, which high flow rate of water advantageously effects the prevention of scales from depositing therearound which is quite undesirable yet inevitable in waste heat boilers. With such tubular construction in the heat exchanging section of this boiler, it is not necessary to provide a very thick boiler drum construction as in the conventional waste heat boilers and consequently, there is provided no junction part of the drum and tube plates which has contingently presented troubles from thermal stresses existing thereabout, thereby relieving this particular area from the generation of questioned stresses and contributing substantially to the materialization of a light-weight boiler. For affording a high inner pressure in use, there are provided a series of stays 12 with an effect of reducing a design thickness of the tube plate. Also, the provision of spacers 17 between the inner and outer tubes effects the prevention of vibration and/or eccentricity of these tubes with each other during the operation.
Next, some typical examples of the junction part between the individual tube and the tube plate according to this invention will now be described as follows. Firstly, referring to FIGS. 2(a) and 2(b), there are shown an embodiment such that the tube plate 13 on the hot gas supply side is lined with an insulating or refractory material for the purpose of keeping the temperature of the tube plate 13 at a relatively low level. More particularly, FIG. 2(a) shows a construction where there is provided the outermost tube 7 extending completely through the refractory material layer to the surface thereof, FIG. 2(b) showing one wherein the outermost tube 7 terminates at the surface of the tube plate with the ferrule 9 extending between the inner surface of the refractory material layer and partly the entrance end of the tube 5 as shown in an attempt to effect a smooth flow of hot gases and to prevent possible damage of the castable refractory material caused by errosion. Also, in the design shown in FIG. 2(b), it is further advantageous that the tube end may be kept at a relatively low temperature by the provision of refractory material in comparison with the case of FIG. 2(a). Next are still other embodiments of the invention shown in FIGS. 2(c) and 2(d) wherein the tube plate 13 is omitted in construction, and this feature may be applied particularly in the case that the temperature of hot gases is relatively low, or at a gas outlet section and the like. Moreover, according to the constructions shown in FIGS. 2(a), 2(b) and 2(c), there is provided the cap 7a or 8a joining the outermost tube 7 or 8 and the inner tube 5, respectively, serving as a flexible joint that can effectively absorb a thermal expansion to exist in the outer tube 6 and the inner tube 5. On the other hand, FIGS. 2(e) and 2(e') illustrate further constructions such that there are provided outermost tubes 7 or 8 and caps 7a or 8a having a regular hexagonal shape in cross-section, respectively, in an attempt that they may be arranged snugly adjacent to each other free from any gaps therebetween, so that they can be accommodated in the highest number within a given area, accordingly. That is, these parts are formed with tubes 7c, 8c of a honeycomb structure. This specific structure can readily be formed by arranging and welding constituent elements to be hexagonal in cross-sectional shape. For the connection of the inner tube 5 to the hexagonal outermost tube 7c or 8c, there is provided a cap 7d or 8d having a hexagonal cross-sectional shape at its opening base and this cap may be welded in position to surround the ends of these tubes. These caps 7d, 8d serve as a flexible joint like those 7a, 8a described in conjunction with the foregoing embodiment. It is also possible to provide the refractory material and/or tube ferrules in the like manner as in the embodiment shown in FIG. 2(b).
As fully stated hereinbefore, there are a variety of structures of stream distribution and collection at the junction parts between the tubes and tube plate and therefore, it is now practicable to combine at choice such variations in the determination of an optimal structure under a given design condition.
Needless to mention, the improved construction of a waste heat boiler according to this invention can be applied satisfactorily to a general heat exchanger other than the application as described herein by way of preferred embodiments thereof.
While the present invention has been described in detail by way of specific preferred embodiments thereof, it is obvious to those skilled in the art that many other modifications and variations may be made without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention is not restricted to such variations, but is covered only by the appended claims.
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A waste heat boiler which comprises a water chamber and a water vapor chamber, both surrounded by an opposed pair of tube plates, respectively, and a plurality of double tubes extending across the two chambers. The inner tubes within the double tubes are adapted to pass hot waste gases therethrough, while annular spaces defined between the inner and outer tubes within the double tubes are for directing water to be heated therethrough. At least one end area of the double tubes is of triplicate structure so that thermal stresses generated from thermal expansion of the tube elements may be absorbed effectively.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of coiled tubing in a well, and more particularly, to a tapered connector for joining lengths of coiled tubing with differing outside diameters.
2. Description of the Prior Art
After a well has been completed to produce oil or gas, it is necessary to periodically service the well. There are many occasions where the service procedure is carried out using coiled tubing. Such tubing is inserted into the wellhead through a lubricator assembly or stuffing box. Typically, this is necessary because there is a pressure differential at the surface of the well and the atmosphere, which may have been naturally or artificially created, that serves to produce oil or gas or a mixture thereof from the pressurized well. The tubing is inserted by an injector which generally incorporates a tubing guide, or gooseneck, and a plurality of gripper blocks for engaging the tubing and moving it through the injector. One such injector apparatus is shown in U. S. Pat. No. 5,553,668, assigned to the assignee of the present invention.
The tubing is relatively flexible and can therefore be cyclically coiled onto and off of a spool, or reel, by the injector which often acts in concert with a windlass and a power supply which drives the spool or reel. In the injector, the gripper blocks are attached to movable gripper chains. The gripper blocks sequentially grip the coiled tubing that is positioned therebetween. When the gripper chains are in motion, each chain has a gripper block that is coming in contact with the coiled tubing as another gripper block on the same gripper chain is breaking contact with the coiled tubing. This continues in an endless fashion as the gripper chains are driven to force the tubing into or out of the wellbore, depending on the direction in which the drive sprockets are rotated.
In the past, such coiled tubing has had a constant cross section. However, maintaining a constant diameter for the tubing can present some problems under certain circumstances. For example, it may be desirable to reduce the weight of the string, and this cannot be done if the string has a constant diameter. Further, a larger string causes more drag in the wellbore, particularly when the strings are being used in a horizontal or other deviated portion of the well. There is a need, therefore, for a tubing string with different sized portions. The present invention provides a solution to this problem by providing a string having a tapered connection therein between two lengths of tubing having differing diameters. This is accomplished by providing a tapered connector which provides an elongated tapering tubing string portion which is connected at opposite ends thereof to a larger tubing portion and a smaller tubing portion.
For example, a larger outside diameter tubing at the top of the string and a smaller outside diameter tubing at the bottom allow the coiled tubing string to be designed for longer lengths by reducing the hanging weight of the string and also reduces the percent of yield load on the larger diameter portion compared to a string having a single outside diameter.
The present invention also provides for use of a smaller outside diameter portion in a horizontal or deviated well formation, thus reducing the drag of the tubing while still having the larger diameter portion at the top of the string to push the string further into the well because of the decreased buckling of the large portion.
Another problem with constant diameter tubing relates to the key issue of pressure drop therethrough. If the wellbore size at the treatment area is small, then previously a small diameter length of tubing had to be used. The smaller diameter tubing could present significant pressure drop problems. The present invention solves this by allowing the use of larger outside diameter tubing close to the treatment zone with a smaller portion actually at the treatment zone.
All of these embodiments are possible due to the V-shaped groove design of the gripper blocks in the Halliburton injector system which allows tubing of varying outside diameters to be engaged by the same blocks.
SUMMARY OF THE INVENTION
The apparatus of the present invention utilizes one or more tapered connectors in a tubing string for use in servicing a well. Thus, the invention provides a tubing string for use with a tubing injector for injecting tubing into a wellbore wherein the string comprises at least a first tubular portion having a first tubing outside diameter, a second tubular portion having a second tubing outside diameter which is different than the first tubing outside diameter, and a tapered portion disposed between the first and second tubing portions. The tapered portion comprises a first end having a first end outside diameter substantially equal to the first tubing outside diameter and a second end having a second end outside diameter substantially equal to the second tubing outside diameter. The tapered portion is preferably substantially conical.
The tapered portion may be connected to the first and second tubing portions by a variety of means. For example, it can be crimped, swaged, screwed or welded to the connection. A first connector may be used interconnecting the first tubing portion and the first end of the tapered portion, and a second connector may be used interconnecting the second tubing portion and the second end of the tapered portion. These first and second connectors may be integrally formed with the tapered portion. Multiple tapered portions with connectors may be utilized in a tubing string to connect differing diameter tubings into a string for servicing a well.
In the preferred embodiment, the first and second connectors are substantially cylindrical. The first connector has a first connector outside diameter substantially equal to the first tubing outside diameter, and the second connector has a second connector outside diameter substantially equal to the second tubing outside diameter.
The present invention also includes a method of running tubing in a wellbore comprising the steps of (a) providing a tubing string having an outer surface with a plurality of outside diameters, and (b) injecting this tubing string into the wellbore. Step (a) comprises providing the tubing string with a tapered connector between adjacent tubing portions having different outside diameters. Step (b) comprises passing the tapered connector through a tubing injector for injecting the tubing into the wellbore. This injector is provided with a plurality of gripper blocks therein adapted for engaging and gripping the tapered connector and the different outside diameters of the tubing string as the tubing string is injected into the wellbore.
Stated in another way, the invention includes a method of running tubing into a wellbore comprising the steps of (a) positioning a tubing injector adjacent to a wellhead at an upper end of a wellbore, (b) positioning a tubing string through the injector, the tubing string being provided with an outer surface having more than one outside diameter, and (c) actuating the tubing injector for injecting the tubing string in the wellbore. Step (c) may include passing a tubing connector therethrough which interconnects the portions of the tubing string having different outside diameters.
Numerous objects and advantages of the invention will become apparent with the following detailed description of the preferred embodiment is read in conjunction with the drawings illustrating such embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows the tubing connector of the present invention interconnecting two portions of a tubing string having different outside diameters as the tubing string is passed through a tubing injector into a well.
FIG. 2 shows a detail of the engagement of gripper blocks in the tubing injector with the tubing string.
FIG. 3 is a cross section taken along lines 3 — 3 in FIG. 2 .
FIG. 4 is a longitudinal cross section of the tubing connector portion of the tubing string.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and more particularly to FIGS. 1 and 2, the tubing connector of the present invention is shown and generally designated by the numeral 10 . Connector 10 interconnects a first tubing section or portion 12 and a second tubing section or portion 14 . First tubing section 12 , second tubing section 14 and tubing connector 10 may all be said to form portions of a tubing string 16 .
Typically, tubing string 16 is supplied on a large drum or reel 18 and is typically several thousand feet in length. Tubing string 16 is in a relaxed but coiled state when supplied from drum 18 . Tubing string 16 is typically spooled from the drum 18 supported on a truck (not shown) for mobile operations.
An injector apparatus 20 is mounted above a wellhead 22 adjacent to a ground surface 23 on a superstructure 24 . Extending upwardly and away from superstructure 24 is a guide framework 26 having a plurality of pairs of guide rollers 28 and 30 rotatably mounted thereon.
Tubing string 16 is supplied from drum 18 and is run between rollers 28 and 30 . As tubing string 16 is unspooled from drum 18 , generally it will pass adjacent to a measuring device, such as wheel 32 . Alternatively, the measuring device may be incorporated in injector 20 , such as described in U.S. Pat. No. 5,234,053 to Connell, assigned to the assignee of the present invention.
Rollers 28 and 30 define a pathway for tubing string 16 so that the curvature of the tubing is slowly straightened as it enters injector 20 . There is enough play in rollers 28 and 30 to accommodate different-sized tubing diameters. As will be understood, tubing string 16 is preferably formed of a material which is sufficiently flexible and ductile that it can be curved for storage on drum 18 and later straightened. While the material is flexible and ductile, and will accept bending around a radius of curvature, it runs the risk of being pinched or suffering from fatigue failure should the curvature be severe. Rollers 28 and 30 are spaced such that straightening of the tube is accomplished so that the tubing is inserted into the well without kinks or undue bending.
Referring now to FIGS. 2 and 3, the details of the interaction between tubing string 16 and injector 20 will be discussed. Inside superstructure 24 , a pair of gripper chains 34 and 35 are driven by a corresponding pair of gripper chain drive sprockets 36 and 37 , respectively. Gripper chain drive sprockets 36 and 37 are mounted on drive shafts 38 and 39 , respectively and driven thereby by a prime mover (not shown) in a manner known in the art. The lower portion of gripper chains 34 and 35 are supported by gripper chain idler sprockets 40 and 41 , respectively mounted on idler shafts 42 and 43 .
Gripper chains 34 and 35 are of a kind known in the art, and each has a plurality of outwardly facing tubing gripper blocks 44 thereon. As best seen in FIG. 3, each gripper block 44 has a V-shaped groove 46 defined on the outer face thereof. The V-shape of groove 46 allows the blocks to automatically adjust for different diameters on tubing string 16 . That is, a larger outer surface 48 on tubing string 16 will be positioned further outwardly in groove 46 than a smaller diameter portion. Drive sprockets 36 and 37 and idler sprockets 40 and 41 are biased toward tubing string 16 in a manner known in the art so that gripper chains 34 and 35 generally conform to the outer surface of tubing string 16 . As seen in FIG. 2, when tapered connector 10 passes through injector 20 , gripper blocks 44 will grip along tapered outer surface 48 thereof. Gripper chains 34 and 35 are rotated in opposite directions so that the gripper blocks 44 on both which engage tubing string 16 move downwardly to force the tubing string into the well. This can be reversed to pull tubing string 16 out of the well. The V-shaped grooved surface of gripper blocks 44 in the Halliburton injector allow the differing outer surfaces of tubing string 16 to be substantially simultaneously engaged.
Referring now to FIG. 4, a cross section of the portion of tubing string 16 which includes tapered connector 10 is shown. Connector 10 is substantially conical in the preferred embodiment. Preferably, the maximum outer diameter 50 of tapered connector 10 is substantially the same as outside diameter 52 of first tubing section 12 . Similarly, the minimum outside diameter 54 of connector 10 is substantially the same as outside diameter 56 of second tubing section 14 . The upper end of tubing connector 10 is connected to first tubing section 12 by a first connector section 58 , and the lower end of tapered connector 10 is attached to second tubing section 14 by a second connector section 60 . In the illustrated embodiment, first and second tubing sections 12 and 14 and tapered connector 10 are metal, and first and second connector sections 58 and 60 are characterized by welded portions between tapered connection 10 and first and second tubing sections 12 and 14 , respectively.
Alternatively, tapered connector 10 can have an internal nose that is integral thereto at each end. The noses are inserted into first and second tubing sections 12 and 14 . The tubing sections then can be crimped or swaged onto the tapered connector. In still another embodiment, the tapered connector can be threadingly engaged with the first and second tubing sections 12 and 14 . Tapered connector 10 and first and second tubing sections 12 and 14 may be made of a non-metallic composite material.
In any of the embodiments of tapered connector 10 , the key feature is that the outer surface of tubing string 16 be relatively smooth so that tapered connector 10 provides a substantially even and gradual transition between first tubing section 12 and second tubing section 14 . In this way, tubing connector 10 will pass smoothly through injector 20 and be substantially uninterruptedly engaged by gripper blocks 44 so that tubing string 16 is injected into the well.
If desired, multiple tubing sections having different diameters can be connected as described hereinafter to produce a tubing string for treating a well. For example, a larger outside diameter tubing at the top of a string may be connected to a smaller outside diameter tubing which in turn is connected to a yet smaller outside diameter tubing by multiple tapered connectors to reduce the hanging weight of the string and thereby reduce the yield loading on the tubing string upper sections.
It will be seen, therefore, that the tapered connector for a tubing string of the present invention is well adapted to carry out the ends and advantages mentioned as well as those inherent therein. While a presently preferred embodiment has been shown for the purposes of this disclosure, numerous changes in the arrangement and construction of parts may be made by those skilled in the art. All such changes are encompassed within the scope and spirit of the appended claims.
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A tapered connector for a tubing string. The present invention includes a tapered connector used in interconnecting sections of the tubing string having differing outside diameters. The connector is preferably conical and fixedly attached to the tubing portions in various ways, such as welding. The tubing string can be injected into a well by using a tubing injector with gripper blocks having a V-shaped groove defined therein adapted for engaging the different diameter tubing sections and the tapered connector and methods of injecting are also disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the wet chemical etching of holes and grooves in semiconductors using a maskless etchant with substantially zero dark etch rate and a light induced etch rate which is easily controllable. As an example, in InP crystal is etched by H 3 PO 4 under illumination by 5145 Angstroms light, and has a substantially zero dark etch rate.
2. Description of the Prior Art
Heretofore wet chemical etching of semiconductors has utilized methods which require the deposit of a mask. The mask has openings which permit the etchant to contact the surface at only those locations where it is desired for etching to occur. A problem not solved in the prior art is the maskless etching of semiconductor crystals.
A review of etching techniques for GaInAsP/InP structures is given by Coldren et. al. in their article "Etched Mirror and Groove-Coupled GaInAsP/InP Laser Devices for Integrated Optics", published in IEEE Journal of Quantum Electronics, Vol. QE-18, pp. 1679-1688, October 1982, which article gives 39 references, all of which are herein referred to for background information.
The use of photoelectrochemical etching has been found to give good light to dark etch ratios, but requires the application of an electric potential in order to remove the etched material, as discussed by Ostermayer et. al. in their article "Photoelectrochemical Etching of P-GaAs" Published in Applied Physics Letters, Vol. 39, pp. 76-78, July 1981.
Haynes et. al. in their article "Laser-Photoinduced Etching of Semiconductors and Metals", published in Applied Physics Letters, Vol. 37, p. 344, August 1980, used etch solutions of bromine and iodine as active species, dissolved in aqueous solutions containing high concentrations of various corresponding alkali halide salts, specifically NaBr, KBr, CsBR, or NaI, KI, CsI. Laser wavelengths of 4131 Angstroms, 5208 Angstroms, and 6328 Angstroms were used to enhance etching.
In the article by von Gutfeld et al., "Laser Enhanced Etching in KoH", published in Applied Physics Letters, Vol. 40, p. 352, February 1982, etching of Si and several ceramic materials submerged in aqueous KOH solution was enhanced by laser illumination. They suggest three important factors in the etching process; (1) direct removal of material through melting; (2) increase in the effective surface area in contact with the etchant; and (3) the local temperature increase which promotes the thermally activated kinetics of etching.
Osgood et. al in their article "Localized Laser Etching of Compound Semiconductors in Aqueous Solution", published in Applied Physics Letters, Vol. 40, p. 391, March 1982, used a variety of etchants for various crystals, for example: GaAs (Cr-doped, semi-insulating) in aqueous H 2 SO 4 ; GaAs (n-type) in aqueous KOH; CdS (undoped) in aqueous H 2 SO 4 and H 2 O 2 ; and InP (Fe-doped semi-insulating) in aqueous HCl and HNO 3 . They observed that for photon energies below the bandgap of GaAs, there was no light-induced increase in etching rate for GaAs.
SUMMARY OF THE INVENTION
The problem of providing for semiconductors a wet chemical etch which does not require a mask capable of withstanding the etch has been solved in accordance with the present invention. A light beam is focused to a desired spot size upon the crystal to be etched, for example InP, while the crystal is in contact with a liquid etch solution, for example 10% aqueous H 3 PO 4 , and etching proceeds during illumination and stops in the absence of illumination. The light may, alternatively, be projected in a pattern upon the surface of the crystal and etching proceeds at the brightly illuminated portions of the pattern.
Other and further aspects of the present invention will become apparent during the course of the following description and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, in which like numerals represent like parts in the several views:
FIG. 1 is a side view showing the light-induced etching apparatus;
FIG. 2 is a front view of a crystal during etching;
FIG. 3 is a side view showing the apparatus used to measure the dark etch rate;
FIG. 4 is a side view showing a dark etch rate;
FIG. 5 is a side view of an etched groove which was exposed by cleaving;
FIG. 6 is a top view of discontinuous groove etched in pure water;
FIG. 7 is a front view of an etched groove showing gas bubble formation;
FIG. 8 is a graph showing "optimum power" plotted versus scan rate;
FIG. 9 is a semilog graph showing etch rate vs. light power;
FIG. 10 is a top view showing an illumination pattern produced upon a crystal surface by interference;
FIG. 11 is a side view showing a sample being etched into a thin cross section by a broad light beam;
FIG. 12 is a profile of a sample etched by a broad light beam as shown in FIG. 11;
FIG. 13 is an isometric view of a series of parallel etched grooves;
FIG. 14 is a side view showing flow patterns in etchant solution;
FIG. 15 is a side view showing flow patterns in etchant solution; and
FIG. 16 is a side view of a mask which is imaged onto a sample by a lens.
DESCRIPTION OF THE PREFERRED EMBODIMENT
EXAMPLE 1
Referring to FIG. 1 there is shown a side view of a light-induced etching apparatus 50. Laser 52 produces light beam 52 which first passes through optical isolator 56 and becomes optical beam 60 upon emerging therefrom. Optical beam 60 is focused by lens 62 to a small spot 64. Sample 66 is located at the focal plane of lens 62. Sample 66 is surrounded by container 70 which holds etchant solution 72. Mount and scanning apparatus 74 supports container 70 and sample 66, and provides linear scanning in the direction perpendicular to the plane of FIG. 1. Light beam 60 is focused to spot 64 at the surface of sample 66. Light beam 60 is partly absorbed by sample 66 at spot 64, and is partly reflected as light beam 80. Reflected light beam 80 is substantially prevented from entering laser 52 by optical isolator 56.
During the process of adjusting the optics it is convenient to remove optical isolator 56, tune the laser intensity down to just below its threshold for lasing, and then adjusting the angular orientation of sample 66 so that light beam 80 reflects into laser 52; this additional feedback is sufficient to initiate lasing. When the laser begins to lase as a result of adjusting the orientation of sample 66, then the exposed plane of sample 66 is oriented perpendicular to laser beam 80.
The sample is then adjusted to lie at the focal spot of laser beam 60 as focused by lens 62 by observing the threshold for lasing. The sample is located at the focus when the threshold for lasing has a minimum value as the sample is moved along the laser beam.
By translating container 70 in the plane perpendicular to the plane of FIG. 1, spot 64 sweeps out a line on sample 66 as is shown in front view in FIG. 2. Solid lines 86 show the edges of a groove etched into sample 66. Dashed lines 88 show the track which light beam spot 64, reference numeral 90 in front view, will sweep out. Arrow 92 shows the direction of motion of sample 66. Laser beam 54 remains stationary as sample 66 moves in the focal plane of lens 62. Alternatively, sample 66 may remain stationary as laser beam 54 is moved with respect to sample 66.
Referring to FIG. 3, a sample 96 is shown in position in etchant 72 for the purpose of measuring the dark etch rate. FIG. 4 shows an edge view of a sample which experienced a dark etch rate. Sample 96 is submerged to line 100 for a fixed time. The volume of material 102 removed from one face during the submerged time gives the dark etch rate. Alternatively, the dark etch rate may be measured by the depth of step 101 as a measure of the volume of material removed during the submerged time.
A light beam spot size may be specified by the parameter w o for a light beam which has a substantially Gaussian intensity profile. The following formula is fitted to the light beam intensity profile:
I(r)=I.sub.o e.sup.-2r.spsp.2.sup./w.sbsp.o.spsp.2
In the equation, I o is the intensity at the center of the light beam, r is the radius at which the intensity is evaluated (measured from the center of the light beam), and w o is a parameter which gives the spot size. The parameter w o will be referred to as the light beam "spot size" in this patent.
The depth of a depression or of a surface irregularity may be measured by a method referred to as "alpha stepped". The method uses, for example, a probe which touches the surface and which registers the depth of a surface irregularity on a dial. Equipment manufactured for alpha stepped measurements includes, for example, Alpha Step Model 10-00020 made by Tencor Instruments, Inc. The alpha stepped method is of sufficient sensitivity that surface features of 0.5 micron may be readily measured.
EXAMPLE 2
Continuous wave argon laser light at 5145 Angstroms was used to induce rapid localized etching of InP samples immersed in aqueous solutions of phosphoric acid. No etching of the samples was observed in the absence of the light. Typically the etchant was a (1:9) solution of concentrated H 3 PO 4 in deionized water. As an example of the etch rates attained, 100 μm diameter holes were etched through 250 μm thick samples in 30 sec. using 2W of light focused on the sample to a spot diameter of about 20 μm.
Grooves were etched in a planar face of the samples. Typical grooves obtained with 700 mW of light focused to a 20 μm diameter spot and using a scan rate of 40 μm/sec measured 15 μm wide and 15 μm deep. The grooves have rounded bottoms and steeply sloping walls. For a given scan rate there is a small range of "optimum powers" which yield continuous, straight, smooth grooves. For powers slightly above or below this power range the grooves that result are discontinuous, irregular in width and depth, and not straight. The optimum powers and volumetric etch rates for semi-insulating, undoped (slightly n-type), and heavily n-type samples are similar. The optimum powers are lower and the etch rates are faster for p-type material. Luminescence studies of the samples after etching indicate that the etching process causes little damage to the surrounding material.
Referring to FIG. 5 there is shown a profile of a typical groove etched as described hereinabove. The profile as obtained by cleaving the crystal along a plane substantially perpendicular to the groove and photographing the groove through a microscope. Sides 110, 112 are smooth and sloping and do not follow any particular crystal plane. Bottom 114 is rounded. Surface 116 is substantially free of debris. Width W 120 and depth d 122 are controlled by the light power, the scan speed at which the crystal is moved, the light spot size, and the constituents and concentration of the etchant.
Referring to FIG. 6, there is shown a series of discontinuous holes 130 rather than a smooth uniform groove. Such discontinuous holes may be etched if the light power is too great, if the light power is too little, if the etchant is pure water rather than a solution of H 3 PO 4 , or by other combinations of reaction conditions. Depths of discontinuous holes may be as much as 50 to 100 microns rather than grooves of depths of 10 to 20 microns.
Referring to FIG. 7, there is shown a bubble 134 of gas which forms when excessive light power is used. The bubbles 134 forms in the vicinity of the focal spot 64. The bubble 134 deflects the light beam from focal spot 64, thereby leading to discontinuous etching rather than etching of a smooth groove.
A number of light intensity conditions and etchant concentration conditions have been studied.
EXAMPLE 3
Etch Hole, no scanning of Sample
Light power 1W
Lens 10 cm focal length
Methanol etchant
Good holes produced. However, piles of material piled up on the surface near the hole.
EXAMPLE 4
Light power 3W
Lens focal length 10 cm
Sample thickness 200 micron
Light spot size: focal spot ≃50 micron
Etchant 10% H 3 PO 4 in H 2 O
A hole of diameter approximately 250 microns was produced in several minutes. The sample may not have been located in the focal plane of the lens.
EXAMPLE 5
Light power 2W
Lens 4.3 cm focal length
Light spot size w o ≃8 micron
Etchant 10% H 2 SO 4 in H 2 O
A hole formed in 90 sec. and was completely etched after 120 sec. The sample may not be in the plane of the lens.
In Example 6 through Example 8 the etchant is 10% H 3 PO 4 in water.
EXAMPLE 6
Light power 1W
Lens 4.25 cm focal length
Some etching of the sample occurred but after 5 min. there was not a hole through the 200 micron-thick sample.
EXAMPLE 7
Light power 2W
Lens 4.25 cm focal length
Focal spot ≈5 micron
Light begins to break through 200 micron-thick sample within 25 sec. and is fully through at 30 sec. The hole is quite clean and the alpha step measurement confirms. The hole diameter is 250 micron. The hole on the rear surface is smaller and is oblong shaped.
EXAMPLE 8
Light power 1.5W
Lens 4.25 cm focal length
Spot focal size w o ≃5 microns
The light breaks through the sample in 45 sec. and full transmission occurs in 50 sec. Hole diameter is 100 to 125 microns, and is smaller on rear surface. The surrounding area is smooth.
Table 1, as follows, gives Example 9 through Example 42. Accurate measurements of the laser beam used in the example given in Table 1 are: (a) the spot size incident onto the 4.25 cm focal length lens is w o =1.1 mm; (b) the focal spot size in air of the above-mentioned 4.25 cm focal length lens is w o =9 micron. Note that 2w o =18 micron and the groove width for Example 23 is 20 micron. Thus, grooves can be etched with widths of approximately the spot size, 2w o . An undoped InP crystal was used. Optical isolator 56 shown in FIG. 1 was not installed.
The sample was scanned to etch grooves. The following etch conditions apply to the examples given in Table 1.
Etchant 10% H 3 PO 4 in H 2 O
Lens 4.25 cm focal length adjust focus accurately
focal spot size w o =9 micron
TABLE 1__________________________________________________________________________ Scan Light Description of GroovesGood Speed Power Depth WidthExampleGroove mm/sec. Watt Microns Microns Comments__________________________________________________________________________ 9 1 2 3.5 -- rough edges10 2 2 ≃1 -- discontinuous holes11 4 2 43 smooth grooveX 0.4 2 312 1 4 2.5 -- discontinuous holes13 2 4 1.75 -- discontinuous holes14 4 4 -- discontinuous holes15 0.4 4 3.8 -- groove with jagged and broken sides16 0.2 2 20 -- jagged sides17 0.2 1.5 5.0 35 smooth groove18 X 0.2 1.4 over 8 smooth sides19 0.1 1.4 X -- grooves broken up by bubbles clinging to sample20 0.2 1.0 X -- grooves broken up by bubbles clinging to sample21 X 0.1 1.0 7 25 smooth straight sides22 0.04 0.5 <1.0 no groove shows on S.E.M.23 X 0.04 0.75 10 20 vertical smooth walls, the best groove through this example.24 X 0.4 2.4 15 50 smooth sides25 X 0.4 2.0 11 45 smooth sides26 X 0.4 3.0 7 65 smooth sides27 1 4.4 -- shallow28 1 3.9 -- shallow29 0.02 0.5 -- very shallow30 0.02 0.6 -- very shallow31 0.02 0.7 -- very shallow32 0.68 3 --33 0.68 3.535 0.68 2.536 0.68 337 0.68 2.538 0.04 0.75 not 20 uniform39 X 0.04 0.8 15 2340 X 0.04 0.78 15 2041 X 0.04 0.78 15 2042 X 0.04 0.78 15 22.5__________________________________________________________________________
An optical isolator 56 shown in FIG. 1 was installed in the laser beam to avoid reflections from the sample causing gain fluctuations in laser 52. However, as mentioned hereinabove, observation of laser gain fluctuations was used to adjust the sample into the focal spot. In Table 2 are presented Examples 43 through 51, and the parameters are:
Etchant 10% H 3 PO 4 in H 2 O
Lens 4.25 cm focal length
Spot size in focal plane w o =9 micron
Optical isolator installed
TABLE 2______________________________________ Description Scan Light of Groove Good Speed Power Width DepthExample Groove mm/sec Watt Micron Micron______________________________________43 0.4 No good results found for power 1.25 W through 2.5 Watt44 X 0.2 1.25 25 845 X 0.2 1.5 30 1246 X 0.1 1.0 21 847 X 0.1 1.2 20 1448 X 0.04 0.6 12 849 X 0.04 0.6 15 10-1550 X 0.04 0.7 14 1051 X 0.04 0.75 16 15______________________________________
For powers less than the smallest for each scan speed given in Table 2, the grooves tend to be discontinuous and the width and depth vary erratically.
A trend may be recognized from the foregoing examples through the definition of a quantity called "optimum power". Optimum power is defined as the least light beam power which gives continuous "good" grooves of substantially constant depth. The optimum power is the minimum power for etching good grooves. Referring to FIG. 8, there is shown a graph of "optimum power" defined hereinabove plotted along the vertical axis 140 versus scan rate plotted along the horizontal axis 142. The data points 144 for a beam width parameter w o =9 micron are shown as solid points, and a data point 146 for w o =approximately 2 microns is shown as an open circle.
Grooves etched with the same conditions as shown in Table 2 but with a light spot size of approximately 2.0 micron are given in Table 3.
TABLE 3______________________________________ Description Scan Light of Groove Good Speed Power Width DepthExample Groove mm/sec Watt Micron Micron______________________________________52 * .04 1 10 1053 * .04 1.2 12.5 16______________________________________
EXAMPLE 54
Grooves etched as in Example 52 are excellent. Using the conditions of Example 52, 5 grooves of less than 10 microns width and separated by 25 microns were etched with a scan speed of 0.04 mm/sec and light power of 1 Watt.
EXAMPLE 55
Shallow depressions are etched with light power of 40 milliwatt. Such depressions may be etched during adjustment of the sample and the laser before beginning an etch run.
EXAMPLE 56
Flourescence of InP surfaces is used as an indication of surface quality. Samples before etching have a good flourescence. Samples after etching have poor flouresence. However, flourescence may be restored to etched samples by treating them as follows: (a) submerged for 2 to 3 minutes in buffered HF; (b) submerged for 2 minutes in 2:1 glacial acetic acid: 30% H 2 O 2 . Restoration of flourescence by the above treatment indicates that the surface is oxidized during etching, and the oxide layer suppresses flourescence.
EXAMPLE 57
Etching in pure deionized water using the laser beam with w o =9 microns was attempted. The etch produces a series of strung together deep holes. The smoothest line of holes is produced with a scan rate by 0.04 mm/sec and with a laser power of 0.7 Watt. The holes resemble a periodic structure seen in the good grooves produced with H 3 PO 4 etchant.
EXAMPLE 58
An etchant concentration of 20% H 3 PO 4 gives an optimum scan rate of 0.04 mm/sec with a light power of 0.7 Watt. Grooves are shallower but smoother than those produced with 10% H 3 PO 4 . A conclusion is that optimum scan rate is independent of concentration of H 3 PO 4 . Thus the concentration of H 3 PO 4 may be chosen to produce the shape of groove which is desired.
EXAMPLE 59
The dark etch rate of InP in a 10% H 3 PO 4 aqueous solution was measured as shown in FIG. 3. Sample 96 was suspended in the etchant for 76 minutes. Removed material 102, as shown in FIG. 4, provides a step at location 100 which was at the surface of the etchant. The sample was alpha stepped in order to measure the step at location 100. No step was observed. The measurement technique was sensitive to a step of 0.5 micron which would show very clearly. The step was much less than 0.5 micron. The dark etch rate may be estimated as less than: ##EQU1##
The etch rate for hole etching can be estimated from the data: 30 seconds are required to go through a 250 micron sample.
Etch Rate=250 micron/30 sec=8 micron/sec The light induced enhancement is therefore 8×10 4 .
The etch rate for groove etching can be estimated from the following data: light power 1 Watt; groove 20 micron wide; groove 10 micron deep; scan speed 0.1 mm/sec=100 micron/sec; ##EQU2## The light induced enhancement is therefore 5×10 5 .
EXAMPLE 60
Referring to FIG. 9, there is shown a graph of logarithm of the etch rate plotted along vertical axis 150 versus laser power plotted along horizontal axis 152. The graph is plotted on semilogarithmic paper. The data points 154 fall very close to straight line 156 which was drawn to connect the points. The proximity of data points 154 to a straight line as shown in FIG. 9 is an indication that the etch rate is an exponential function of light power.
A theory which predicts an exponential dependence of a chemical reaction rate is the theory that the controlling independent variable is temperature. Since the light power affects the temperature of the sample by which it is absorbed, the graph shown in FIG. 9 supports the theory that the enhancement of etch rate by the light beam is due to a temperature rise of the sample. In addition to a temperature rise of the sample, excitation of electrons and holes in the sample may increase the chemical reactivity of the sample.
The method of light enhanced etching using an etchant with a low dark etch rate is expected to work on compounds containing In and P such as GaInAsP and other quaternaries, and also compounds such as GaAs, GaAlAs, and InGaAlAs. Also semi-insulating InP with doping of Fe or Mn or other similar acceptor materials is expected to exhibit light enhanced etching. Localized heating of the crystal by the light beam is believed to account for the dominant mechanisms involved in the enhancement of etching by light. Therefore light which is absorbed by similar materials will have a similar effect of enhancing their etching.
EXAMPLE 61
Referring to FIG. 10, there are shown two light beams 160, 162 which converge at the surface of a sample 159 to be etched. The light beams 160, 162 interfere and produce bright fringes, two of which are shown, 164, 166. At locations where the bright fringes 164, 166 illuminate sample 159, etching of sample 159 is enhanced and produces grooves 170, 172. The fringe spacing d 174 should be kept larger than the heat diffusion length of the sample as it is submerged in the etchant solution.
EXAMPLE 62
A thin sample for transmission electron microscopy may be made using light enhanced etching. Referring to FIG. 11, there is shown a light beam 180 with an approximately Gaussian intensity profile. The laser beam is spread out to a w o of approximately 0.5 cm. Light beam 180 illuminates sample 182 and thereby enhances its etching. Because light beam 180 is of greatest intensity at its center, the etching of sample 182 proceeds most rapidly near its center 184. A photodiode 186 may be used to monitor penetration by light beam 180 through sample 182. In one mode of operation, etching may be allowed to proceed until the light beam 180 penetrates sample 182, and then may be halted by turning off light beam 180 when photodiode 186 senses light penetration of sample 182. This mode of operation would produce a sample with a small hole and with very thin edges surrounding the hole. Such thin edges make an ideal target for a transmission electron microsope.
EXAMPLE 63
A typical depression etched by a broadened Gaussian profile light beam is shown in FIG. 12. The profile is seen to have smooth sides 191. Also the profile has a width 193 corresponding to the width of the light beam. For example, width 193 may be a few millimeters.
EXAMPLE 64
Referring to FIG. 13, there is shown an isometric view of a series of parallel grooves 200 etched in a crystal of InP 202. Grooves 200 have a width 204 and a depth 206. Control of the etching process is illustrated by the ends 208, 210 of the grooves. Etching stops when the light beam 54 is turned off.
EXAMPLE 65
Selective etching of materials with different bandgap energies is accomplished by tuning the laser photon energy. Etching of a layer of material with a smaller bandgap energy while selectively not etching another material with a higher bandgap energy is done by tuning the laser photon energy between the two bandgaps. Then absorption occurs and etching proceeds in the lower bandgap material. Etching does not proceed in the wider bandgap material because very little light absorption occurs due to the wider bandgap.
For example, the bandgap of InP is around 1.0 micron photons, whereas that of InGaAsP is around 1.3 micron photons, and therefore light of the correct wavelength is absorbed by the InGaAsP and not the InP. Thus with the proper etchant solution the InGaAsP may be selectively etched.
Alternatively an etch can be selective if two materials have quite different threshold intensities, or if absorption is nonlinear, or if they have very different nonlinearities.
EXAMPLE 66
A 10% HCl in H 2 O solution was used as an etchant for InP. The scan rate was 0.04 mm/sec and light power of 0.75 Watt. A very nice groove of 14 microns wide by 10 microns deep was produced.
Conditions of scan speed of 0.1 mm/sec with light power of 1.0, 1.25, or 1.5 Watt did not give good etching.
EXAMPLE 67A
A sample of n-doped InP, doped with sulfur at a concentration of n≃5 10 18 cm -3 , was etched. The conditions of 10% aqueous H 3 PO 4 , a scan rate of 0.04 mm/sec, and a light power of 0.75 Watt provided excellent etching results. A groove of 15-16 microns width and 18 microns depth was etched.
Additional examples of etching of n-doped InP with doping of sulphur at a concentration of n≃5×10 18 cm -3 are given in Table 4.
TABLE 4______________________________________n-type InP sulfur doped n ≃ 5-10.sup.18 cm.sup.3, 10%H.sub.3 PO.sub.4 Description of Groove Scan EtchEx- Speed Light Rateam- Quality of mm/ Power Width Depth Micron.sup.3 /ple Groove sec Watt Micron Micron sec______________________________________67 good-smooth .04 .8 19 20 15.2 × 10.sup.368 good-smooth .04 .8 19 19 14.4 × 10.sup.369 good-smooth .04 .75 18 16 11.5 × 10.sup.370 good-smooth .1 1.0 24 12 28.8 × 10.sup.371 good-smooth .1 0.9 21 8 16.8 × 10.sup.3______________________________________
The results given in Examples 67 through 71 do not differ greatly from the results obtained with undoped InP.
Etching of p-doped InP, doped with zinc at a concentration of p≃2×10 18 cm -3 using 10% H 3 PO 4 was done. Table 5 gives examples of conditions which gave etched grooves.
TABLE 5______________________________________p-doped InP doped with zinc, p≅2 × 10.sup.18 cm.sup.310% H.sub.3 PO.sub.4 Description Scan Light of Groove Quality of Speed Power Width DepthExample Groove mm/sec Watt Micron Micron______________________________________72 good but .04 0.8 -- -- not optimum72 continuous & .04 0.7 19 15 straight73 continuous & .04 0.6 19 13 straight74 good .04 .65 19 1375 good .04 .6 19 1376 best .04 .5 16 1277 best .04 .4 15 778 good but .1 1.2 -- -- not optimum79 good but .1 1.0 -- -- not optimum80 best .1 .8 22 1481 best .1 .7 19 10______________________________________
EXAMPLE 82
Care must be exercised in placing a sample to be etched within an etchant container. Flow within the solution may impinge on the inner surface of the container. Flow turbulence generated by currents impinging upon the inner surface of the container may disturb the light beam focus, may wash against the sample surface where they deposit material or etch away the surface, or may otherwise interfere with the etching process. Referring to FIG. 14 and FIG. 15, there are shown flows in an incorrect and correct placement, respectively. In FIG. 14 the sample 220 is too close to wall 222 of container 224, and flow 226 strikes wall 222 causing turbulence in etchant solution 228.
In FIG. 15 sample 220 is further away from wall 222 and so flow 226 does not cause turbulence and does not disturb light beam 230. Flow 226 also does not deposit material or cause unwanted etching of other parts of sample 220.
EXAMPLE 83
A light beam may illuminate a mask, and an image of the mask may be focused upon a sample to be etched. The mask is not in contact with the sample, and is not immersed in the etchant. Referring to FIG. 16, there is shown a light beam 240 which illuminates an opaque mask 242 which has a transparent pattern, for example transparent locations 224A, 244B, 244C, and 244D. Light passing through transparent openings is focused by lens 246 onto sample 248. For example, transparent location 244A is focused to location 250A where it illuminates sample 248. Also, for example, transparent locatio 244D is focused by lens 246 to location 250D on sample 248 where sample 248 is illuminated. Sample 248 is immersed in etchant solution 252 which is held in container 254. Etching proceeds rapidly at illuminated regions of sample 248, for example location 250A and location 250D. The pattern of mask 242 may thereby be etched into sample 248 as a pattern of grooves.
Semi-insulating InP doped with Fe was etched using an etchant of 10% H 3 PO 4 in water. A lens of focal length 4.25 cm with a light spot size w o =9 microns was used. Good grooves were etched with the conditions of light intensity and scan rate given in Table 6.
TABLE 6______________________________________Semi-insulating Fe doped InPetchant 10% H.sub.3 PO.sub.4 in waterlight spot size .sup.3 w.sub.o = 9 micron Description Scan Light of Groove Quality of Speed Power Width DepthExample Groove mm/sec Watt Micron Micron______________________________________84 good but .04 .6 16 10 depth varies somewhat85 best, constant .04 .7 18 16 depth86 good .04 .8 20 20______________________________________ The following materials are suitable for etching in aqueous H.sub.3 PO.sub.4 under the influence of illumination by light while in contact with the H.sub.3 PO.sub.4 solution: undoped InP, p-doped InP, n-doped InP, Fe-doped semi-insulating InP, compensated doped InP, alloys of InP and As, alloys of InP and GaAs, and alloys of InGaAlAs.
It is to be understood that the above-described embodiments are simply illustrative of the principles of the invention. Various other modifications and changes may be made by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.
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A method of etching a semiconductor crystal is given. The crystal includes elements selected from one of the groups: (a) indium and phosphorus; (b) gallium and arsenic; (c) aluminum and arsenic. The method comprises the steps of placing the crystal in an aqueous solution of H 3 PO 4 or HCl, and while the crystal is in contact with the solution illuminating predetermined regions of the crystal with light so that etching proceeds at the illuminated predetermined regions much more rapidly than at nonilluminated regions of the crystal. The method also includes focusing the light to a small spot on the crystal and moving the spot on the crystal so that a groove is etched in the crystal.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a device for personal cleaning and, more particularly, to a device for removing undesired matter from a user's tongue and, even more particularly, the invention relates to a tongue-treating device for removing plaque and debris from the tongue in order to prevent halitosis and for applying a treating substance onto the tongue.
BACKGROUND OF THE INVENTION
[0002] Halitosis is a concern for many people affected of this disorder that is chronic or pathological disorder stemming from non-oral sources as well as oral sources. Studies have shown that about 85% patients suffering from halitosis have an oral condition as the source. Measures of oral malodor suggest that it is caused mainly by tongue coating as the result of anaerobic sulfur producing bacteria, which normally live within the tongue. This bacteria is supposed to be there because they assist digestion by breaking down proteins found in specific foods, mucus, blood, and death cells. Under certain conditions, they start to break down the proteins found in those specific foods.
[0003] Tongue coating comprises desquamated epithelial cells, blood cells, bacteria and mucus. The morphology of the dorsal surface of the tongue is very irregular with the presence of multiple fissures and filiform and fungiform papillae. These fissures and crypts may create a unique ecological site were microorganisms are well-protected from the flushing action of the saliva and where oxygen levels are low enhancing the growth of anaerobic bacteria. Saliva from nearby glands drips down on the posterior region of the tongue, which is full of irregularities. The bacteria on the tongue are also a potential contributor to periodontal disease and other oral health problems. This coating on the tongue also causes a loss of taste since it dulls the taste receptors. Furthermore, since the human tongue has numerous protuberances, e.g., papillae, which convey to the brain the senses of taste and touch, the tongue can easily become a breeding ground for microorganisms such as bacteria, as well as a repository for food debris, volatile sulfur compounds (which are a major cause of halitosis) and dead cells. Over time, some of the collected material becomes a soft plaque which is another cause of bad breath. This soft plaque is known to attack the teeth and gums.
[0004] Still further, the anaerobic bacteria break down specific components of the coating of the tongue creating certain gases or volatile sulfur compounds (VSCs). These VSCs have been implicated as a major contributing factor to halitosis. Consequently, the removal of the tongue coating reduces VSCs production and longer lasting reductions in VSC levels are followed after tongue scraping. Methods that involved cleansing of the dorsoposterior surface of the tongue caused the most pronounced reductions of halitosis.
[0005] Tests have shown that daily scraping to reduce the amount of coating on the tongue eliminates much of the undesirable bacteria and sulfur compounds, thus significantly inhibiting plaque formation on the teeth in the long term, and substantially reducing halitosis in the short term. However, the surface cells of the tongue are sensitive to injury. Therefore, the removal of the bacteria and waste material should be performed in a manner which respects the sensitivity of the tongue.
[0006] While the inventor is aware of several devices that can be used to scrape the tongue, the inventor is not aware of any tongue scraping device that will not only scrape the tongue in a manner which respects the sensitivity of the tongue but will also provide a means for cleansing and disinfecting the tongue.
SUMMARY OF THE INVENTION
[0007] The above-discussed disadvantages of the prior art are overcome by a tongue cleaning device that includes a sponge-like tip that is fluidically connected to a refillable reservoir that will contain mouthwash or the like. A scraper is located adjacent to the tip and a check valve in the reservoir prevents fluid from flowing away from the tip in the event the orientation of the device is suddenly changed.
[0008] Using the tongue cleaning device embodying the present invention will permit a user to clean his or her tongue, especially in the back, using a soft sponge that can be coated with liquid that will not only clean the tongue but will serve as a mouthwash. Once the sponge cleaning is completed, the user can simply flip the device over and scrape off the tongue.
[0009] Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0010] The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.
[0011] FIG. 1 is a front elevational view of a tongue cleaning device embodying the present invention.
[0012] FIG. 2 is a rear elevational view of the tongue cleaning device shown in FIG. 1 .
[0013] FIG. 3 is a side elevational view of the tongue cleaning device shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to the figures, it can be understood that the present invention is embodied in a tongue cleaning device 10 which will permit the cleaning and scraping of a user's tongue as well as the dispensing of liquid such as mouthwash which will further enhance the cleaning function. Device 10 comprises a handle 12 which has a first end 14 which is a forward end when the handle is in use, a second end 16 which is a rear end when the handle is in use and a longitudinal axis 18 which extends between first end 14 and second end 16 of the handle.
[0015] Handle 12 is hollow and has a fluid-accommodating chamber 20 defined therein. Liquid, such as mouthwash or the like is contained in chamber 20 . Screw threads 22 are located adjacent to second end 16 . The first and second ends of the handle are open to the chamber so fluid can be placed in the chamber and can flow out of the chamber as will be understood from the teaching of this disclosure. The chamber is re-fillable via the second end of the handle. Handle 12 further includes a first surface 30 and a second surface 32 . Handle 12 is elongate and is in the shape of a toothbrush handle in the form shown in the figures.
[0016] A one-way check valve 40 is located in fluid-accommodating chamber 20 near first end 14 of the handle. The check valve is oriented in the handle to permit fluid located in the fluid-accommodating chamber to flow in direction 42 toward the first end of the handle and to prevent fluid located in the fluid-accommodating chamber from flowing in direction 44 from first end 14 toward the second end of the handle.
[0017] A base 50 is threadably mounted on the handle at the second end of the handle and closes the fluid-accommodating chamber at the second end of the handle when the base is in place on the handle. The base can be used to stand device 10 in an upright orientation as shown in the figures. This will enable the device to be stored and used in an efficient manner.
[0018] A tongue scraper element 60 is located on second surface 32 of the handle adjacent to first end 14 of the handle. The tongue scraper is used in the manner known to those skilled in the art to scrape the user's tongue, especially near the back of the tongue. A sponge-mounting bracket 64 is mounted on first surface 30 of the handle adjacent to first end 14 . Further sponge mounting elements, such as brackets 66 , are also located on the handle.
[0019] A fluid port 70 is defined through first surface 30 of the handle and through sponge-mounting bracket 64 . Fluid port 70 is in fluid communication with fluid-accommodating chamber 20 via check valve 40 . Fluid in chamber 20 will flow in direction 42 toward port 70 but will not flow in direction 42 away from port 70 so that if the device is tipped during use, fluid will not flow away from port 70 .
[0020] A fluid-dispensing sponge 80 is releasably mounted on first surface 30 of the handle by sponge-mounting bracket 64 and brackets 66 . The sponge is in fluid communication with fluid-accommodating chamber 20 via fluid port 70 . The sponge is replaceably mounted on the handle so it can be used and then replaced as often as necessary.
[0021] Use of device 10 can be understood from the teaching of the foregoing disclosure and thus will only be briefly discussed. A user stores device 10 on the base 50 with fluid in chamber 20 . The device is used by washing a user's tongue with the sponge which will also apply fluid to the tongue. The device can also be used to scrape the user's tongue by scraping scraper 60 over the tongue. Fluid can be replaced in chamber 20 as needed.
[0022] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.
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A tongue cleaning device includes a sponge-like tip that is fluidically connected to a refillable reservoir that will contain mouthwash or the like. A scraper is located adjacent to the tip and a check valve in the reservoir prevents fluid from flowing away from the tip in the event the orientation of the device is suddenly changed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to Provisional Application Ser. No. 60/714,473 for “Drainage System and Method Using Mount Reduction Techniques” filed on Sep. 6, 2005 and is a continuation-in part of both patent application Ser. No. 10/702,857 filed on Nov. 6, 2003 and application Ser. No. 10/994,809 filed on Nov. 22, 2004 both now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to underground drainfield systems and methods for treating, filtering, cleaning, discharging and recycling septic tank effluent or drainfield water in difficult soil conditions that historically have required an above ground mound system or an intermittent sand filter.
2. The Prior Art
In the United States, a growing number of households rely upon a septic system rather than centralized wastewater treatment facilities. In fact, approximately one fourth of households in the United States use a septic system to treat, filter, clean and disburse wastewater. A typical septic system consists of a septic tank, a distribution/filtration box and some form of an underground disposal field. Several types of underground disposal fields have been developed and are known in the art. The most common type is a drainfield, also known as a leach field or absorption field. There have been several variations of drainfields, including mound systems, sand filters and dig outs.
Once sewage undergoes treatment in a septic tank, the resulting effluent is transported to the drainfield. This is accomplished by either gravity or through a mechanical pump, with the goal of uniformly discharging effluent below ground into the soil for final treatment and disposal. Another goal of the drainfield is to naturally filter the post-septic tank effluent to remove any remaining pathogens, bacteria, or biomass prior to flowing into the ground water. Sizing of a drainfield depends upon several factors including the area of the property, the number of individuals in the household, water usage habits of the household, on-site soil conditions, and government regulations. One typical form of a drainfield comprises a collection of multiple parallel-perforated pipes connected by one or more distribution pipes that allow distribution of effluent into the surrounding ground soil for filtration.
Historically, construction of a drainfield has been expensive, time consuming and inconvenient. Construction usually begins with the excavation of a large rectangular cross section of land by digging multiple trenches at least three feet deep to lay the necessary perforated pipes. These trenches are usually less than 100 feet long, and dug to create an essentially flat bottom. In one prior art drainfield construction, each trench is first filled with a layer of gravel. Next, a perforated pipe is placed in the trench, with an additional six-inch layer of gravel added to surround the perforated pipe. A geotextile fabric or a similar product is placed over the approximately two feet of gravel. Finally, a covering layer of backfill soil is added. This entire process requires transport of large amounts of gravel, backfill soil and piping from a distribution center to the drainfield site. The steps of digging trenches, creating a network of piping and laying different layers of filtering media requires specialized equipment, multiple experienced workers, time, and large amounts of natural resources.
In many areas of the country, unique soil conditions require a modified drainfield known as a mound or raised drainfield. In areas with high groundwater, shallow soil over impermeable soil or slowly permeable soil, a mound must be created above ground to allow proper distribution and filtration of post-septic effluent. However, above ground mounds often require a mechanical pump to raise effluent from the septic tank above ground to the mound. Second, mounds require transport of additional natural resources to the site. Third, mounds are typically unsightly and greatly reduce the use of the land. Lastly, mounds require a relatively larger area than conventional drainfields and also require routine monitoring and maintenance.
For areas with high ground water or impervious soil, one alternative for a mound or raised drainfield is an intermittent sand filter. An intermittent sand filter is a water impermeable basin placed in the ground containing a network of perforated pipes located in a sand bed. The water impermeable basin is first filled with a layer of aggregate, most commonly pea gravel. Next, a second layer of medium grade clean sand is added to the basin to create the sand bed. A network of perforated pipes is placed on top of the sand bed. A second layer of aggregate is then added to the basin. A larger perforated outflow pipe is typically placed within the basin for collection of filtered effluent that then enters the drainfield.
Although intermittent sand filters reduce the need for a mound, improve the appearance of the underground disposal field and allow for better use of the ground, there are several disadvantages. First, intermittent sand filters require transporting large volumes of heavy sand to the drainfield site, which can be very costly. Second, intermittent sand filters require very large cross sections to be effective. For example, a typical two-bedroom home would require a sand filter nineteen by nineteen feet in cross section. Thus, these systems can only work with large acreage households. Third, most intermittent sand filters require a mechanical pump, which results in greater energy and maintenance costs.
Apart from intermittent sand filters and mound systems, a third type of drainfield called a “dig out” has also been used in the art. With a dig out, a large cross sectional area of the soil near the septic tank is excavated to remove poor soil. Good quality soil is then transported to the site through one or more commercial vehicles. The good soil is then evenly deposited within the excavated area. A network of perforated piping is assembled and placed on top of the newly deposited soil, which is connected to either a distribution box or directly to the septic tank. Backfill soil is then added over the network of perforated piping. While this method of creating a drainfield has some benefits with respect to an intermittent sand filter, the overall costs, manpower and natural resources required to create a dig out system are significantly greater.
There exists a need for an alternative to intermittent sand filters and mound drainfields for efficient treatment, filtration, and distribution of effluent. In addition, there is a need for a filter media that is light weight, portable, inexpensive and allows for increased filtration to decrease the cross sectional size of these systems. Finally, there is a need for such systems to be modular for easy transport to the drainfield site, to allow improved fabrication of these systems, for further reduction in overall costs.
SUMMARY OF THE INVENTION
This invention is directed to a system and method for treating, filtering, disbursing, discharging and recycling effluent, or any form of wastewater, in difficult soil conditions that historically required either an unpleasant mound or an intermittent sand filter.
The present invention comprises a filtration system that includes a sub-system referred to herein as the Mound Reduction Filter Unit (“the MRFU”) and the associated method as the “Mound Reduction Filter Method” (“the MRFM”). In one embodiment, the MRFU is located downstream from a septic tank and is connected to the tank either directly or through an intermediate distribution/filtration sub-system. Aided by gravity, post-septic effluent leaves the septic tank and preferably travels to a distribution sub-system where it is filtered for any remaining sludge, particulates, residue or biomass. Within this post-filtration chamber, effluent is treated for removal of bacteria and pathogens. The effluent then leaves the distribution unit through a second pipeline into the MRFU. Within the MRFU, one or more perforated pipes uniformly distributes the effluent through the MRFU for additional treatment and filtration of any remaining pathogens, bacteria or human waste. In a preferred embodiment, the cleansed effluent then leaves the MRFU through either a slotted linear grate or a series of screened portals into a discharge pipe and then flows to a drainfield reserve.
The MRFU comprises a watertight basin that is preferably rectangular, but can be of any shape that provides a sufficient volume of effluent filtration and treatment. The MRFU is made of any resilient material, preferably a lightweight plastic and comprises a bottom, connected sidewalls, and a removable top. The removable top preferably includes a geotextile fabric. Connected at each corner of the bottom side of the removable top are metallic members to permit the MRFU to be opened for maintenance or inspection.
The MRFU is filled with filter media that can be any combination of aggregate, soil, sand, gravel, rock, beaded material, or the like. The preferred filter media is variable sized expanded polystyrene (E.P.S.) beads having a diameter on the order of one-eighth inch or less.
The MRFU is sized to allow easy transport to a drainfield site via a commercial vehicle. Using a modular construction, several MRFUs can be attached together in parallel or in series depending upon the size and site conditions of the installation.
A drainage unit it positioned below the MRFU and functions to transport post-MRFU filtered effluent to the drainfield reserve. The drainage unit comprises two components, a discharge pipe and a culvert. Preferably, the discharge pipe is fabricated from high-density polyethylene (H.D.P.E) or a similar material.
Several forms of the culvert are suitable; for example, a rectangular slotted culvert that connects through a slot in the MRFU can be used. Such an arrangement is taught in co-pending application Ser. No. 10/702,857. The slotted portion prevents filter media from escaping the MRFU during effluent transport through the discharge pipe and can be of any known type of grate or a mesh. The top side of the slotted culvert is fitted with the bottom of the MRFU, allowing filtered effluent to flow downward into the discharge pipe.
In a second embodiment, one or more grated portals form a linear relationship along the top shaft of the discharge pipe and permit passage of the filtered effluent from the bottom of the MRFU into the discharge pipe while retaining the filter media in the MRFU. These portals are preferably positioned equidistantly along the shaft and in one example are attached on top of a single discharge pipe. Alternatively, a series of component members are attached to linear tubing portions, allowing the use of standard industry H.D.P.E. tubing. These members are either a ninety degree elbow (the initial portion) or a “tee” shaped portion (along the shaft) above which is a grated portal structure. The interface between the drainage unit and MRFU is preferably watertight.
From this grated culvert or series of portals, effluent flows downward from the MRFU into the discharge pipe. In another arrangement, the discharge pipe contains a filter media, such as expanded polystyrene (E.P.S.) beads, allowing additional treatment and filtration of effluent. The discharge pipe underneath the MRFU is preferably linear and longer than the total length of the MRFU with a portion of the discharge pipe extending beyond the MRFU in a direction opposite the inlet to the MRFU. The extending portion of the discharge pipe preferably comprises two generally ninety-degree turns, creating an “S”-shaped flow path. To ensure proper flow of effluent via gravity, the end of the “S” shaped portion of the discharge pipe is below the inlet entering the MRFU. This shape should allow flow from the discharge pipe into the drainfield reserve, without need for a mechanical pump.
The end portion of the “S” shaped portion of the discharge pipe is connected to one or more reservoir retention chambers, forming a drainfield reserve. These retention chambers are preferably elongated mesh tubes filled with a filter media such as expanded polystyrene aggregate (E.P.S.). A perforated pipe can be placed within the elongated mesh tubes to permit flow to be directed from the discharge pipe throughout the filter media. These elongated mesh tubes are positioned in a generally downward direction from the MRFU allowing gravity to transport effluent along the drainfield reserve. From the drainfield reserve, the effluent then enters the ground water.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention, as well as alternative embodiments, are described by way of example with reference to the accompanying drawings in which:
FIG. 1 is a cross sectional schematic view of a septic system according to this invention.
FIG. 2 is a top schematic view of the septic system shown in FIG. 1 .
FIG. 3 is a top schematic view showing a septic system that includes three parallel Mound Reduction Filter Units (MRFUs), with accompanying drainage units and drainfield reserves.
FIG. 4 is a perspective view of the Mound Reduction Filter Unit (MRFU) and drainage unit sub-systems of the present invention.
FIG. 5 is a perspective view of the drainage unit sub-system.
FIG. 6 is a perspective view of an alternative embodiment of the drainage unit shown in FIG. 5 .
FIG. 7 and FIG. 8 are cross-sectional side views of alternative embodiments MRFU-drainage unit constructions.
DETAILED DESCRIPTION
The present invention will now be described with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments shown in the drawings and described in this specification. Rather, these illustrated embodiments are intended to convey the scope of the invention to those skilled in the art.
The invention set forth herein provides improved filtration for any effluent or drainage setting, and is not limited to distributing and filtering post-septic tank effluent. For example, the invention can be applied to watershed runoff, collection of rainwater along roads and use in small commercial sites for non-toxic water disposal. Other related uses will be clear to those skilled in the art. However, FIGS. 1 through 8 illustrate the present invention embodied in a septic system for filtering sewage from a septic tank and, for purposes of illustration includes (i) a combination distribution and filtration sub-system for removing biomass and bacteria, (ii) a sub-system that functions as an alternative to drainfields described herein as a Mount Reduction Filter Unit (“MRFU”), (iii) a drainage unit for collection and transport of post-MRFU effluent, and (iv) a drainfield reserve for final distribution of cleansed effluent into the soil and ground water.
FIGS. 1 , 2 4 and 5 illustrate a preferred embodiment 10 of a filtration system according to this invention. Wastewater flows from a household 12 to a conventional septic tank 14 through a distribution pipe 16 below ground. Within the septic tank 14 , the suspended solids within the wastewater separate according to their density, with heavier solids resting at the tank bottom and lighter solids floating on the surface. Cultures of bacteria are deposited into the septic tank 14 that decompose the solids and other suspensions. Wastewater is usually deposited from the household 12 into the septic tank 14 in periodic intervals throughout the day, most typically in the morning, in the late afternoon and in the evening. Within the period of wastewater deposits, there is a retention time sufficient to allow the cultures to decompose the solids and other suspensions. After this retention time, a subsequent wastewater deposit pushes post-septic effluent from the septic tank 14 into a distribution/filtration sub-system 18 through a post-septic distribution conduit 20 .
The distribution/filtration sub-system 18 is preferably rectangular, but could be of any shape known in the art that allows for proper filtration and distribution of effluent. The sub-system 18 preferably comprises three sections: a pre-filtration chamber 22 , a filter 24 , and a post-filtration chamber 26 . Preferably contained within the post-filtration chamber 26 are chlorine tablets 28 .
The distribution/filtration sub-system 18 may be fabricated in accordance with the teachings of U.S. Pat. No. 6,277,280, the disclosure of which is incorporated herein by reference.
Effluent into the pre-filtration chamber 22 is then separated by the filter 24 . The filter can be a screen, multiple slits throughout the surface of a plane, a perforated grate or a resilient mesh bag filled with expanded polystyrene (E.P.S). Any residual sludge remains in the pre-filtration chamber 22 . The post-filtered effluent then contacts the chlorine tablets 28 for removal of bacteria and further decomposition of any remaining suspensions. During retention times when there is no incoming wastewater into the system, the concentration gradient between the super-chlorinated post-filtered effluent in chamber 26 and the incoming pre-filtered septic effluent causes dissolved chlorine to move across the filter 24 and into the pre-filtration chamber 22 . This further destroys remaining bacteria in the sludge and supports further decomposition of remaining biomass in the sub-system 18 . In the event that the filter 24 becomes clogged due to accumulated sludge, the top of the sub-system 18 can be removed, and the filter can be easily replaced or the sludge can be pumped from chamber 22 .
The effluent out of sub-system 18 flows through a post-filtration conduit 30 into a Mount Reduction Filter Unit (MRFU) sub-system, referred to generally with reference numeral 32 . The MRFU 32 is a basin having a bottom 34 , four connected walls including end walls 36 , 38 , side walls 37 , 39 and a removable top 40 . The removable top 40 may include means allowing the MRFU 32 to be opened for maintenance or inspection. The conduit 30 is a distance below distribution conduit 20 , allowing effluent to flow through the system 10 without the need for a pump.
Effluent from the sub-system 18 flows into the MRFU 32 through an effluent distribution pipe 42 . The distribution pipe 42 can be a single perforated pipe or a network of perforated pipes. Within the MRFU 32 , filter media 44 permits further cleansing of post-filtered effluent from the sub-system 18 . Along the bottom 34 of the MRFU 32 there is one or more slits or openings to allow post-MRFU cleansed effluent to exit the MRFU 34 via a drainage unit as described in greater detail below.
FIGS. 2 through 6 better illustrate the MRFU 32 , its internal components and potential arrangements of multiple modular units. The MRFU 32 is preferably rectangular, but can be of any size or shape that provides a sufficient volume to permit complete cleansing and filtration of the effluent from the sub-system 18 . While the sizing of the MRFU 32 can vary, the preferred shape is sufficient to permit the unit to be transported via a flat bed truck or similar commercial vehicle, allowing for uniform fabrication of the MRFU 32 to reduce construction and installation costs. The MRFU 32 can be constructed of any material that permits the unit to be waterproof. Preferred materials for the MRFU 32 include plastic, lined concrete, corrugated material, PVC or any other known water impervious material. Depending upon the size of the household or the household's generation of wastewater, more than one MRFU 32 can be used. As an example, a parallel arrangement of three units 32 is illustrated in FIG. 3 . However, the invention also contemplates multiple modular units placed in series or both parallel and in series, depending upon either or both the treatment demands or acreage space constraints.
The internal construction of the MRFU unit 32 is illustrated in greater detail in FIG. 4 , where the walls, top and bottom of the MRFU 32 are shown by dotted lines. The filter media 44 can be any suitable material including but not limited to sand, pea gravel, soil or rock. However, as described above, the preferred filter media 44 for the MRFU 32 is variable sized expanded polystyrene (E.P.S) beads that are one-eighth inch or less in diameter. There may be one or more different layers of filter media within the MRFU 32 . By way of example, three separate layers of filter media 44 are shown in FIG. 4 , including a top layer of lightweight large polymer aggregate 46 , an intermediate layer of expanded polystyrene 48 , and a lower layer of heavy small-sized polymer aggregate 50 . One advantage of using expanded polystyrene beads 48 is that some particulates in the effluent may have a static charge.
Attention is now directed to FIGS. 1-4 . Positioned through the MRFU 32 , is an effluent distribution network that connects effluent flow to the MRFU 32 from either a sub-system 18 or directly from the septic tank 14 . In one arrangement the effluent distribution network includes a central pipe 42 coupled with a series of evenly spaced lateral perforated pipes coupled to the central pipe 42 . Other shapes and arrangements for the effluent distribution network can be envisioned by those skilled in the art. As shown by flow arrows in FIG. 4 , the effluent flows into the effluent distribution network through the pipes 42 , 43 and then downward throughout the filter media and into the drainage unit, referred to generally in FIG. 4 with reference numeral 60 .
FIG. 5 shows one embodiment of the drainage unit 60 , which includes a discharge pipe 62 and a generally rectangular grated culvert 64 . The discharge pipe 62 is preferably rigid and made of high-density polyethylene (H.D.P.E.); however, alternative materials include sheet metal, corrugated material, PVC, lined concrete or any similar material known in the art. The rectangular grated culvert 64 is attached via a watertight seal 66 on top of the rigid discharge pipe 62 , and functions as a drain to filter and direct the flow of effluent from the MRFU 32 . The grated culvert 64 has a preferably grated or mesh top 68 , four enclosing side walls 70 , and an open bottom 72 that forms a watertight seal with the top of the discharge pipe 62 . The grated culvert 64 is preferably made of the same material as the discharge pipe 62 .
As shown in FIGS. 1 , 2 , and 5 , an “S” shaped unit 74 located at the distal end 63 of the discharge pipe 62 is connected to one or more reservoir retention chambers 76 each of which is coupled with a drainfield reserve 78 . The “S” shaped unit 74 may, for example, comprise of two generally 90 degree turns in the discharge pipe 62 . The “S” shaped unit 74 is positioned below the conduit 30 to allow flow out of the discharge pipe 62 via gravity. The distal end of each “S” shaped unit 74 is then connected to at least one reservoir retention chambers 76 . In a preferred embodiment, each retention chambers 76 comprises a mesh bag filled with expanded polystyrene beads. However, the material within the retention chamber 76 can be any polymer aggregate, pea gravel, rock or related material known in the art. Further, a perforated pipe can be added to the retention chamber 76 for distribution of effluent to a drainfield reserve area adjacent each retention chamber 76 .
FIG. 6 illustrates an alternative embodiment for the connection between the bottom 34 of the MRFU 32 and the drainage unit 60 . In this arrangement, the bottom of the MRFU 32 includes two downwardly extending sidewalls 33 , 35 . The sidewalls are preferably integrally formed with the MRFU 32 . The sidewalls 33 , 35 connect directly with opening 72 in the discharge pipe 62 .
FIG. 7 shows an additional embodiment for the drainage unit. In this alternative arrangement, the drainage unit 80 includes multiple passageways 84 positioned in series along the discharge pipe 82 . One preferred form of such a passageway 84 or system of passages with grates 86 therein. However, one of ordinary skill in the art can envision alternative passageways 84 or shapes for such grated portals. For example, the passageways 84 could be circular, elliptical, square, or any known shape that allows a sufficient cross-sectional area and flow path for transport of effluent to enter the discharge pipe 82 .
While the portals may be attached to a single length of discharge pipe as shown in FIG. 7 , the drainage unit can be constructed of multiple components for assembly on-site, and to further reduce costs, by using commercially available H.D.P.E corrugated tubing.
Such an arrangement is shown in FIG. 8 and described next.
There are three main components in the embodiment of FIG. 8 : (i) a ninety-degree initial member 90 that includes a portal 92 having a grate 94 on the top of the initial member 90 ; (ii) tee shaped secondary members 96 that includes a portal 98 on the top of that member, and portions of HDPE corrugated tubing 98 to connect between these members. Located at the distal end of this multi-component drainage unit is a generally “S” shaped fixture that includes a first ninety-degree “S” portion 100 and a second ninety-degree “S” portion 102 . Between these two portions is a portion of HDPE corrugated tubing 104 . Positioned before the second ninety-degree “S” portion is a final screen 106 to shield any excess particulates, suspensions, or escaped filter media from entering the drainfield reserve 76 . The connections between these multi-component parts, the MRFU 32 , and the reservoir retention chamber 76 should be generally watertight.
Also shown in FIG. 8 is an additional component to the drainfield reserve 76 known as a trough 108 which is an additional tubular mesh bag filled with variable sized polystyrene beads 110 and is positioned just below the reservoir retention chamber 76 at the point where the end of the second ninety-degree “S” portion connects with the beginning of the reservoir retention chamber 76 . The trough 108 assists in distributing post-filtered discharge across the width of the drainfield reserve, as well as prove a buffer or barrier to prevent post-filtered discharge to exist the system mainly at the initial portion of the reservoir retention chamber 76 .
From the description of the underground disposal system set forth above, one of ordinary skill can easily envision several methods for using this apparatus for filtering, treating, distributing and cleansing effluent for introduction into the ground soil.
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An underground system for distributing and filtering post-septic effluent includes an underground watertight basin containing a filter and conduit connecting a septic tank with the watertight basin for transporting the post-septic effluent into the watertight basin. A discharge pipe connected to the watertight basin transports filtered effluent from the watertight basin into a drainfield reserve for introduction into surrounding natural ground soil.
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DESCRIPTION
The invention relates to esters of 1,4-dihydro-2,6-dimethyl-3-(alkoxycarbonyl or alkoxyalkoxycarbonyl)-4-(substituted phenyl)-pyridine-5-carboxylic acid, to their stereochemical isomers and pharmaceutically acceptable salts, to processes for their production and to pharmaceutical compositions containing them.
The invention provides esters of 1,4-dihydro-2,6-dimethyl-3-(alkoxycarbonyl or alkoxyalkoxycarbonyl)-4-(substituted phenyl)-pyridine-5-carboxylic acid, the esters having the general formula I ##STR2## wherein Ar represents a 3-nitrophenyl or 2,3-dichlorophenyl group,
A represents a straight chain or branched chain alkylene group having from 2 to 6 carbon atoms,
R represents a straight chain or branched chain alkyl group having from 1 to 6 carbon atoms, optionally mono-substituted by an alkoxy group having from 1 to 6 carbon atoms, and
R 1 represents an alkyl group having from 1 to 4 carbon atoms,
and further provides pharmaceutically acceptable acid addition salts of such esters.
The invention further provides a process for the preparation of the esters of the general formula I, the process comprising condensing a compound of the general formula II
Ar--CHO (II)
wherein Ar is as above defined with a compound of the general formula III
CH.sub.3 COCH.sub.2 COOA.sub.1 (III)
wherein A 1 represents one of (a) a group R as above defined, (b) a group of the general formula IV ##STR3## wherein A and R 1 are as above defined and (c) a group readily convertible to the group defined in (b) reacting the condensate with a compound of the general formula V ##STR4## wherein if A 1 represents the group defined in (a) then A 2 represents either of the groups defined in (b) and (c) and if A 1 represents either of the groups defined in (b) and (c) then A 2 represents the group defined in (a) to give a compound of the general formula (VI) ##STR5## wherein A 1 , A 2 and Ar are as above defined, and if one of the groups A 1 and A 2 represents a group defined in (c) then converting that one of A 1 and A 2 to a group defined in (b).
It will be understood that various synthetic routes are encompassed within the above process. The reaction scheme below, wherein X represents a halogen atom and the other variables are as above defined, illustrates some of these.
For example, the esters I may be prepared by condensing a haloalkyl acetoacetate IIIa (III: A 1 =AX) with an aldehyde II, reacting the condensate with an alkyl or alkoxyalkyl 3-aminocrotonate Va (V: A 2 =R), and converting the group AX of the resultant pyridine derivative VIa (VI: A 2 =R, A 1 =AX) to a group IV by reacting with 4-cyano-4-(3,4-dimethoxyphenyl)-5-methyl-hexylamine or a derivative thereof (VII).
Alternatively the group IV may be introduced into the compound III before ring formation. These routes start from compound IIIb ##STR6## This is available from the amine VII by conventional alkylation to introduce a hydroxyalkyl group HO-A (compound VIII), and the reaction of the alkylated amine with diketene. In one route, compound IIIb is condensed with an aldehyde II and the product is reacted with a 3-aminocrotonate Va. ##STR7##
The above process includes a synthesis of the pyridine ring. If a pyridine derivative VIa is already available it is only necessary to condense it with an amine VII. This condensation is itself within the scope of the invention. When X represents a chlorine atom, it is preferably carried out in toluene or xylene under reflux, whereas when X represents a bromine atom it may be carried out in dimethylformamide at lower temperature.
The esters I obtained may be purified according to methods known per se. The pharmaceutically acceptable salts according to the invention may be prepared from the bases in a conventional manner. Preferred pharmaceutically acceptable acid addition salts are those of hydrochloric, sulphuric, maleic, succinic, citric, methanesulphonic and toluenesulphonic acids. Their stereoisomers may be separated in a conventional manner.
The esters I and their salts according to the invention possess a valuable antihypertensive activity and are also effective against coronary heart diseases. Accordingly, the invention also provides a pharmaceutical composition comprising an ester of the general formula I as above defined or a pharmaceutically acceptable salt thereof in admixture with a pharmaceutically acceptable diluent or carrier.
The LD 50 of the compounds according to the invention was determined in the mouse per os, according to the method described by C. S. Weil (Biometrics, 8, 249, 1952).
The antihypertensive activity of the esters according to the invention was evaluated in male hypertensive rats (SHR, Wister-Kyoto strain, 15-25 weeks old). The determination of blood pressure was performed by an indirect method (M. Gerald et al., Arzneim, Forsch., 18, 1825, 1968). The animals were prewarmed in a heating chamber at a temperature of from 35° to 37° C. for a period of 15 minutes before pressure determination. The compounds tested by oral route were dissolved or suspended in a 0.5% methylcellulose solution. Controls were given only the vehicle. Systolic blood pressure and heart rate were measured 1, 3, 5 and 7 hours after drug administration by means of a tail-cuff and a pulse transducer.
Coronary dilating activity was evaluated in anesthetized normotensive rats (weighing about 500 g), as the ability to antagonize methacholine induced coronary spasm. Rats were instrumented for methacholine infusion into the coronary ostium, while spastic activity was detected as ST segment elevation in D 2 ECG recording (K. Sakai et al., J. Pharm. Meth., 5, 325, 1981). The compounds tested by i.v. infusion were dissolved in water:dimethylformamide (9:1 by volume). Activity was detected as normalization of ECG tracing after compounds administration during methacholine infusion.
The results of the tests, given in the Table below, show that the esters are of low toxicity, possess valuable antihypertensive activities and can also be considered effective against coronary hear diseases.
TABLE______________________________________ ED.sub.25 LD.sub.50 SHR ED.sub.50 mg/kg os ivCompound os mg/kg mg/kg______________________________________2245 278 6.8 0.3012392 3000 14.9 --2404 3000 17.8 --______________________________________ ED.sub.25 = antihypertensive activity mg/kg ED.sub.50 = coronary dilating activity mg/kg -- = not tested
The invention is illustrated by the following Examples.
EXAMPLE 1
Methyl 2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-ethyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-pyridine-3,5-dicarboxylate
A solution comprising 3.94 g of methyl 2-chloroethyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-pyridine-3,5-dicarboxylate and 5.78 g of 4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethylhexylamine in 12 ml of xylene was refluxed under stirring for 7 hours. At the end of the reaction, the mixture was diluted with ethyl acetate and the solutin wax extracted with dilute hydrochloric acid in order to remove the unreacted amine. The organic solution was dried, the solvent was evaporated off under vacuum, and the residue was washed with diethyl ether, treated with dilute aqueous sodium hydroxide solution and extracted with diethyl ether:ethyl acetate (4:1 by volume). The extract was dried and the solvents were evaporated off under vacuum. The crude product thus obtained was purified by silica gel chromatography, using chloroform as eluent with increasing amounts of ethyl acetate. Pure fractions were collected and evaporated to dryness. The residue was dissolved in methanol, filtered through charcoal, treated with ethanolic hydrogen chloride and evaporated to dryness under vacuum. The residue was washed with warm diethyl ether:acetone mixtures (49:1 and then 24:1 by volume). 2.32 g of the hydrochloride of the title compound (2245) were obtained.
Mp 97°-103° C. (Kofler).
EXAMPLE 2
2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethanol
A solution of 18.9 g of 4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamine and 4.5 g of propylene oxide in 40 ml of methanol was allowed to stand for 24 hours at 20° C. A further 0.75 g of propylene oxide was then added, and after 24 hours at 20° C. the solution was refluxed for 1 hour and then evaporated to dryness in vacuo. The oil thus obtained was purified by silica gel chromatography using chloroform containing increasing amounts of methanol as eluent. The unitary TLC fractions (chloroform:methanol:5N methanolic ammonia 95:5:0.5 by volume) were evaporated to dryness to give 18.78 g of the title compound as an oil.
EXAMPLE 3
2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethyl acetoacetate
2.7 ml of diketene was added, over 10 minutes, to a solution of 11.36 g of the compound prepared in Example 2 in 10 ml of toluene at 80° C. When the exothermic reaction was over, the reaction mixture was heated for 2 hours at 80° C. and, after cooling, it was evaporated to dryness in vacuo. The oily residue was then purified by silica gel column chromatography using ehtyl acetate containing decreasing amounts of petroleum ether as eluent. The unitary TLC fractions (chloroform:methanol 95:5 by volume) were evaporated to dryness in vacuo to give 11.61 g of the title compound as an oil.
EXAMPLE 4
2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethyl α-acetyl-3-nitrocinnamate hydrochloride
A solution of 7.80 g of the compound prepared in Example 3 and 3.26 g of 3-nitrobenzaldehyde in 25 ml of chloroform was saturated with hydrogen chloride at 0° C. After 24 hours at 20° C., the reaction mixture was evaporated to dryness in vacuo and the oil residue was solidified by treatment with diethyl ether. The solid thus obtained was washed with diethyl ether:ethyl acetate 95:5 by volume (6×30 ml) until no trace of 3-nitrobenzaldehyde could be discovered.
8.70 g of the title compound, melting at 75°-100° C., were obtained, as an E-Z isometric mixture, which was used as such for further reactions.
EXAMPLE 5
2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethyl α-acetyl-2,3-dichlorocinnamate hydrochloride
Operating as described in Example 4, but employing 2,3-dichlorobenzaldehyde instead of 3-nitrobenzaldehyde, the title compound was obtained as a brown oil. The compound was an E-Z isometric mixture and was used as such for further reactions.
EXAMPLE 6
Isopropyl 2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-pyridine-3,5-dicarboxylate
A solution of 1.38 g of the compound prepared in Example 4 and 0.33 g of ispropyl 3-aminocrotonate in 4 ml of isopropanol was refluxed for 2.5 hours. After cooling, the mixture was evaporated to dryness in vacuo and the residue was dissolved in dichloromethane and washed with an aqueous solution of sodium bicarbonate. The organic phase was dried and evaporated in vacuo to dryness. The residue was purified by flash chromatography on silica gel using petroleum ether containing increasing amounts of acetone as eluent. The unitary TLC fractions (petroleum ether:acetone 7:3 by volume) were evaporated to dryness. The residue was dissolved in diethyl ether and acidified with hydrogen chloride in diethyl ether to give a solid which was collected, washed with diethyl ether and dried. 0.87 g of the hydrochloride hemihydrate of the title compound (2432) melting at 90°-105° C., was obtained.
EXAMPLE 7
Isobutyl 2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethyl 1,4-dihydro-2,6-dimethyl-4-(2,3-dichlorophenyl)-pyridine-3,5-dicarboxylate
Operating as described in Example 6, but starting from isobutyl 3-aminocrotonate and the compound prepared in Example 5, the hydrochloride hydrate of the title compound (2392), melting at 120°-123.5° C., was obtained.
EXAMPLE 8
2-Propoxy-ethyl 2-[4-cyano-4-(3,4-dimethoxyphenyl)-5,N-dimethyl-hexylamino]-1-methylethyl 1,4-dihydro-2,6-dimethyl-4-(2,3-dichlorophenyl)-pyridine-3,5-dicarboxylate
Operating as described in Example 6, but starting from 2-propoxy-ethyl 3-aminocrotonate and the compound prepared in Example 5, the hydrochloride hydrate of the title compound (2404), melting at 102°-105° C., was obtained.
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##STR1## Esters I (Ar=3-nitrophenyl or 2,3-dichlorophenyl, A=C 2 -C 6 alkylene, R=C 1 -C 6 alkyl optionally C 1 -C 6 alkoxy monosubstituted, R 1 =C 1 -C 4 alkyl) have antihypertensive activity and are effective against coronary heart diseases. They are prepared starting from the aldehyde ArCHO and esters of acetoacetic acid and 3-aminocrotonic acid. Pharmaceutical preparations containing them are also described.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from U.S. provisional patent application No. 60/298,911, filed Jun. 19, 2001.
FIELD
[0002] The field of the present application is micropipettes and microarrays.
BACKGROUND
[0003] A “microarray” is a device that is used in biotechnology and other science research. A microarray can be made by putting a large number of tiny samples on a microscope slide (usually made of glass, nylon, plastic, metal, etc.). In a “cytology microarray,” the samples are typically individual cells or groups of cells (or disrupted tissue) in a solution such as water and alcohol. In a “tissue microarray,” the samples are typically whole tissue (as opposed to the substantially free-floating cells in a cytology microarray). In order to examine the samples in microarray closely, the microarrays are typically stained with special dyes, and/or probed with DNA, proteins or antibodies (or other probes). The microarrays are then examined under a microscope or in a specialized kind of computerized microscope called an image cytometer. This can determine the makeup or identity of the cells or tissues under review. This can be helpful for a variety of medical purposes, such as identifying or diagnosing diseases.
[0004] Tissue microarrays are sometimes advantageous because they keep the cells in their original tissue structure, and thus keep them in their original relationship with each other. However, tissue microarrays can be difficult to create and to assay because they can suffer from problems, known as “artifacts.” For example, when the cells are cut into thin sections, individual cells may be cut in half and thus important information can be lost. When the tissue is cut in thick sections it can be difficult to see the cells, and determine where one cell ends and another begins, because the cells overlap. Further, the tissue sections for one microarray are never precisely the same as the tissue sections for the next microarray because the microarrays are cut from different layers of the tissue. As a loose analogy, this is similar to a loaf of sliced bread. Each slice is a little bit different from the previous slice, and sometimes, in just one slice, the bread changes from middle pieces to an end piece, or even to nothing at all (once the loaf is finished). The same kind of thing happens with the individual cells in the tissue microarrays; the cells in one slice are not the same as the cells in the next slice. Tissue microarrays are also typically expensive to create.
[0005] Cytology microarrays, where the cells have been separated from each other and suspended in a suitable liquid, can be advantageous because they can be less expensive to make, and typically the cells can be put down on the slides in a “monolayer,” which means in a single layer so that there is little overlap of one cell and the next. However, making such cytology microarrays can also be expensive and difficult, for example because of inconsistent dispensing of the micro-volumes of liquid used for the cytology microarrays.
[0006] Accordingly, there is gone unmet a need for inexpensive and simple methods and devices for making cytology microarrays. The present systems and methods provide these and other advantages.
SUMMARY
[0007] The microvolume liquid dispensers disclosed herein provide simple and inexpensive approaches to making cytology microarrays. Briefly, the tips comprise an outer sleeve, typically shaped like a funnel, that holds a needle or pin. The pin moves back and forth inside the sleeve, or reciprocates. The tip of the pin slightly extends beyond the distal opening of the outer sleeve in one position, and is retracted in another position. When the pin is in the extended, or distal, position the shoulders of the pin contact the inner surfaces of the sleeve and block the cytology liquid from flowing through the opening. Thus the pin and sleeve cooperate to form a reservoir behind the blockage. When the pin is pushed up into the sleeve by touching the tip to a glass slide or other substrate, a passage is formed between the outer surface of the pin and the inner surface of the sleeve. The liquid in the reservoir then flows through the passage and onto the slide. Removing the tip from the substrate moves the pin back to its original position, re-forming the reservoir and leaving a precise droplet of liquid—a predetermined microvolume amount of the liquid—on the slide.
[0008] The size and shape of the pin and sleeve can be cooperatively configured in any desired shape so that a precise amount of liquid flows from the reservoir when the tip is contacted with the substrate. Although a wide variety of additional attachments, such as springs or other biasing members, automated motion detectors, etc., can be provided and added, it is an advantage of the present tips that they do not need such attachments; they can be nothing more than routine plastic micropipette tips and simple metal needles (any other desired material can be used for either the sleeve or the pin), and the device can, if desired, be operated solely via manual operation and the effects of gravity.
[0009] In one aspect, the present disclosure provides a microvolume liquid dispenser comprising a body, an outer sleeve extending from the body, and a reciprocating pin located within the outer sleeve. The outer sleeve comprises a distal opening and the pin reciprocates relative to the sleeve between a distal position wherein a distal tip of the pin extends beyond the distal opening and a proximal position. The outer sleeve and the reciprocating pin can be configured to cooperatively form a reservoir when the pin can be in the distal position and configured to cooperatively dispense, through a passage formed between a side of the distal opening and the pin, a predetermined microvolume amount of liquid from the reservoir when the pin moves in a cycle from the distal position to the proximal position then returns to the distal position.
[0010] In some embodiments, wherein the dispenser can be a hand-held dispenser and the body comprises a handle, or the dispenser can be stationary and the body can be attached to a frame sized to fit on a substantially flat surface. (Unless expressly stated otherwise or clear from the context, all embodiments, aspects, features, etc., can be mixed and matched, combined and permuted in any desired manner.) The sleeve and pin can be configured to cooperatively dispense a volume per cycle that is suitable for a cytology microarray, and the passage can be sized to substantially avoid clogging by cells. The sleeve and pin can be configured such that the predetermined microvolume amount can be from about 0.05 μl to 0.5 μl per cycle, or otherwise as desired. The dispenser can further comprise a biasing element operably connected to at least one of the body and the outer sleeve and configured to urge the pin toward the distal position.
[0011] In another aspect, the present disclosure provides a microvolume liquid dispenser tip comprising an outer sleeve and a reciprocating pin located within the outer sleeve, configured to cooperatively interact as discussed above. The inner surface of the sleeve, and the sleeve itself, can be substantially frustoconical and the outer surface of the pin can be correspondingly substantially frustoconical. The substantially frustoconical shape of the pin can comprise a concave curve near the distal tip. The distal opening of the sleeve can have a diameter from about 0.5 mm to 1.5 mm. The tip can be one of an array of the microvolume liquid dispenser tips, which array can be configured and sized to make a cytology microarray.
[0012] In a further aspect, the present disclosure provides a cytology microarray maker comprising a frame operably connected to a body holding an array of microvolume liquid dispenser tips, at least two stages sized to support cytology microarrays, at least one upright member operably attached to the body to move the body and the array of tips substantially normal to the stages between at least an extended position wherein the tips contact a cytology microarray substrate located on the stage and a retracted position wherein the tips do not contact the cytology microarray substrate, and at least one axial member disposed along the frame and operably connected to the upright members to provide a track along which the upright members, the body and the array of tips can be movable along the track between the first and the second stage.
[0013] The microvolume liquid dispenser tips can be configured as discussed elsewhere herein or can be other configurations, and the maker can further comprise at least a third stage. The maker can be stationary and the frame can be sized to fit on a substantially flat surface or other surface as desired. The at least one axial member can comprise two rails extending along the frame, either separately from or as a part of the frame. The upright members can comprise two substantially planar elements slidably connected to the two rails and situated on either side of the stages, the substantially planar elements comprising corresponding elongated axial channels configured to slidably receive projections extending from the body. At least one of the frame and the upright members can be operably connected to body biasing element urging the body away from the stages.
[0014] The stages can be substantially planar stands and can further comprise at least x-axis and y-axis adjustment mechanisms configured to adjust positions of the stages relative to at least one of the frame and each other. The body can comprise a plurality of floating channels each sized to releasably hold one tip. The maker (as with other devices and systems herein) can be substantially automated or substantially manually operated.
[0015] The present disclosure also provides methods of dispensing a microvolume of liquid. The methods can comprise, a) providing a microvolume liquid dispenser tip as discussed herein; b) transiently contacting the distal tip and distal opening with a substrate thereby causing the pin to cycle; and, c) during the cycle, dispensing the liquid to the substrate. The sleeve and pin can be configured to cooperatively dispense a volume per cycle that is suitable for a cytology microarray. The tip can be one of an array of the tips, and the methods can comprise substantially simultaneously transiently contacting the array of tips with a cytology microarray platform, thereby causing the pin to cycle, and thereby forming the cytology microarray on the platform.
[0016] The methods can also comprise, before providing the tip containing the liquid, loading the liquid into the tip by placing the tip into a source of the liquid and suctioning up the liquid using capillary action. The tip can also be loaded by loading the liquid into the tip through a proximal opening located at a proximal area of the tip, or otherwise as desired.
[0017] The present disclosure further provides methods of making a cytology microarray comprising: a) providing a cytology microarray maker as discussed herein; b) loading the array of tips with liquid cytological specimens by transiently moving the array of tips into the liquid cytological specimens and suctioning up the liquid cytological specimens using capillary action; c) moving the array of tips along the axial member to the second stage; and, d) making the cytology array by transiently contacting the array of tips with the cytology microarray substrate. If desired, the microvolume liquid dispenser tips can comprise an outer sleeve and a reciprocating pin as discussed herein. The frame can further comprise a third stage, and the methods can comprise moving the array of tips along the axial member to the third stage; then making a second cytology array. The second cytology array can be made without reloading the tips.
[0018] The methods can comprise sliding the upright members along the two rails between the cytology microarray template and substrate, and then pushing the array downwardly (for example by pushing down on the array itself or on the body) to contact the cytology microarray template and substrate, respectively. The methods can also comprise adjusting the stages on at least one of an x-axis and a y-axis. Where the body comprises a plurality of floating channels each sized to releasably hold one tip, the methods can comprise placing the tips in the body to create the array of tips and removing the tips from the body after making the cytology array. The methods can also comprise removing the cytology array template and the cytology array from the stages then placing new cytology array substrates on the stages and making additional cytology arrays. The additional cytology arrays can be made without reloading the tips.
[0019] The present disclosure still further provides tip means for microvolume liquid dispensing comprising: a) an outer sleeve means for holding the liquid, b) a reciprocating pin means located within the outer sleeve for cooperatively dispensing, through a passage formed between a side of the outer sleeve means and the pin means, a predetermined microvolume amount of liquid when the pin moves in a cycle from a distal position to a proximal position then returns to a distal position. A means for making cytology microarrays can comprise: a) a frame means for holding a body means, b) the body means for holding an array of tips means for dispensing a microvolume of liquid, c) at least two stage means for supporting cytology microarrays, d) at least two upright member means operably attached to the body for moving the body means substantially normal to the stage means, and e) at least one axial member means disposed along the frame and operably connected to the upright members for moving the upright member means between the two stage means.
[0020] A methods of dispensing a microvolume of liquid can comprise the steps of: a) a step of providing a microvolume liquid dispenser tip means, as discussed herein, containing the liquid; b) transiently contacting the distal tip and distal opening with a substrate thereby causing the pin to cycle; and, c) during the cycle, dispensing the liquid onto the substrate. The sleeve means and pin means can be configured for cooperatively dispensing a volume per cycle that can be suitable for a cytology microarray, and the methods comprise the step of dispensing a spot of cell-containing liquid sized for the cytology microarray.
[0021] These and other aspects, features and embodiments are set forth within this application, including the following Detailed Description and attached drawings. In addition, various references are set forth herein, including in the Cross-Reference To Related Applications, that discuss in more detail certain systems, apparatus, methods and other information; all such references are incorporated herein by reference in their entirety and for all their teachings and disclosures, regardless of where the references may appear in this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 depicts schematically a microvolume liquid dispenser tip transiently contacting a cytology microarray substrate and dispensing a desired, predetermined microvolume amount of liquid.
[0023] [0023]FIG. 2 depicts schematically a microvolume liquid dispenser tip configured to dispense a smaller spot of liquid than the tip in FIG. 1.
[0024] [0024]FIG. 3 depicts schematically a microvolume liquid dispenser tip configured to dispense a larger spot of liquid than the tip in FIG. 1.
[0025] [0025]FIG. 4 depicts a hand-held micropipette comprising a microvolume liquid dispenser tip as discussed herein.
[0026] [0026]FIG. 5 depicts a schematically an elevated perspective view of various elements of a cytology microarray maker as discussed herein.
[0027] [0027]FIG. 6 depicts a front-side view of a cytology microarray maker.
[0028] [0028]FIG. 7 depicts a schematically an exploded, elevated perspective view of a tabletop suitable for use with the cytology microarray maker of FIG. 5.
[0029] [0029]FIG. 8 depicts a hand spotted cytology microarray with large spots, made using a funnel without a reciprocating pin.
[0030] [0030]FIG. 9 depicts a hand spotted cytology microarray with large spots, made using a funnel without a reciprocating pin.
[0031] [0031]FIG. 10 depicts a hand spotted cytology microarray with medium spots, made using a microvolume dispensing tip as discussed herein.
[0032] [0032]FIG. 11 depicts a hand spotted cytology microarray with small spots, made using a microvolume dispensing tip as discussed herein.
[0033] [0033]FIG. 12 depicts photomicrographs at different magnifications of a single spot from the cytology microarray of FIG. 8.
[0034] [0034]FIG. 13 depicts photomicrographs at different magnifications of a single spot from the cytology microarray of FIG. 11.
[0035] [0035]FIG. 14 depicts photomicrographs at different magnifications of a single spot from a cytology microarray with small spots made using a microvolume dispensing tip as discussed herein.
[0036] [0036]FIG. 15 depicts screen shots collected by an automated image cytometer for spots created using a funnel without a reciprocating pin.
[0037] [0037]FIG. 16 depicts screen shots of images collected by an automated image cytometer for spots made using a microvolume dispensing tip as discussed herein.
[0038] [0038]FIG. 17 provides graphs demonstrating spot sized in comparison to spot makers comprising a funnel only or comprising a funnel and needle and at different concentrations of cell concentration.
[0039] [0039]FIG. 18 depicts graphs indicating the effect of different alcohol and cellular concentration on spot size and liquid flow through the tips.
DETAILED DESCRIPTION
[0040] High throughput genomic screening methodologies generate very large amounts of genetic, gene expression, and protein content information, and can be mined to determine possible markers (e.g., DNA sequence, mRNA, protein and antibodies to same) for a wide variety of clinical conditions (e.g., disease state, environmental induced damage, infection, or genetic susceptibility markers). Many of these markers can be evaluated, tested, verified and utilized on cellular material such as tissue sections, cytological preparations or extracted cellular components. It is generally accepted that many more markers will be suggested than will eventually be found to be clinically useful. Additionally, these markers are likely to be costly to manufacture and market. Thus, strategies that assist effective testing, verification and utilization of these markers would be of benefit. For these and other reasons, tissue microarrays are made from wax blocks that have tens to thousands of cylindrical tissue samples from random (cylinders adjacent to each other can be arbitrarily determined) arrangements of sources are constructed and used for these purposes. However, tissue microarrays have a number of drawbacks.
[0041] Cytology microarray provide a less labor-intensive, more uniform representation, and use less tissue from a sample. These arrays of spotted (deposited) cytological material may have from one to several thousands of sample cells per spot. The cells deposited may be unfixed, fixed, pre-processed disaggregated cells from solid tissue samples, etc. Each spot of cells may be from different sources, or may be from the same source, or some of each. The spots may be spatially distinct or over lapping. The spatial extent of each spot will be determined by the fluid containing the cells, the surface they are deposited onto and the environment in which they are deposited (humidity, temperature, vapor pressure of the atmosphere, etc.).
[0042] The systems and methods discussed herein provide simple and easy ways to make such cytological microarrays.
[0043] Turning to the Figures, FIGS. 1 - 3 each schematically depict one cycle of a microvolume liquid dispenser tip. In FIG. 1, for example, the microvolume liquid dispenser tip 2 has an outer sleeve 4 and a reciprocating pin 6 . Reciprocating pin 6 is located within the outer sleeve, and may or may not be physically attached to outer sleeve 4 . Outer sleeve 4 comprises a distal opening 16 and an inner surface 14 . As depicted, outer sleeve 4 is substantially frustoconical, ending in distal opening 16 ; other shapes are possible as desired. Reciprocating pin 6 comprises an outer surface 10 , a shoulder 11 and a distal tip 12 . As depicted, the shoulder 11 and distal tip 12 provide a substantially frustoconical form to reciprocating pin 6 . As can be seen in the Figure, in this embodiment shoulder 11 further provides for a concave curve 24 near distal tip 12 .
[0044] When reciprocating pin 6 is in a distal position with respect to outer sleeve 4 , the outer surface 10 of reciprocating pin 6 contacts an inner surface 14 of outer sleeve 4 to substantially form a seal 15 at the point of contact. Because of the seal 15 , any liquid maintained proximal to the seal 15 forms a reservoir 8 . When reciprocating pin 6 is moved proximally relative to outer sleeve 4 , a passage 19 is created between reciprocating pin 6 and a side 18 of distal opening 16 of outer sleeve 4 . Accordingly, liquid, which in FIG. 1 is a cytological fluid 20 , can flow through passage 19 to reach cytology platform 28 which, as embodied in FIG. 1, is a substantially planar substrate. If desired, other forms of substrate, such as substantially spherical or otherwise curved substrates as may be found in the bottom of certain wells of desirable microarray substrates, such as 96-well plates, are also suitable for use. Passage 19 can be sized to substantially avoid clogging by the cells when the liquid being dispensed is a cytological fluid.
[0045] If desired, the reciprocation of reciprocating pin 6 can be caused by various assorted attachments to either the outer sleeve or the pin, for example a biasing element 37 as depicted in FIG. 4, but it is a feature and an advantage of the present systems and methods that no additional elements are necessary to provide the precisely dispensed quantities of cytological fluids or other chemical solutions (such as chemical solution 22 dispensed onto substrate 30 in FIG. 2). Thus, it is inexpensive and easy to move reciprocating pin 6 in a cycle from the distal position to the proximal position and then back to the distal position simply by contacting the dispenser tip 2 with the desired substrate. Similarly, it is possible to load the tip with a liquid merely by placing the tip into the source of the liquid and suctioning up the liquid using capillary action. Conversely, if desired, the liquid may be loaded into the tip through a proximal opening located at a proximal area of the dispensing tip, 2 for example at the top of dispensing tip 2 where it abuts body 36 in FIG. 4.
[0046] The result of moving the reciprocating pin through a cycle is the dispensing, and typically deposit, of a spot of the desired fluid onto the receiving surface such as the cytology platform 28 or substrate 30 depicted in FIGS. 1 - 3 . Thus, a spot 23 is formed on the receiving surface. The spot can be of medium size, as depicted in FIG. 1, of small size as depicted in FIG. 2, or of a large size as depicted in FIG. 3. Generally, the spots comprise from about 0.05 μl to about 0.5 μl with a typical spot being about 0.1 μl. The spots be either larger or smaller if desired. Typically, depending upon the desired format, the solution comprising the cells (or other chemical solution if not a cytological application), the distal opening diameter will typically be from about 0.5 mm to about 1.5 mm, for example about 0.83 mm to 1 mm.
[0047] As already noted, the distal tip 12 of reciprocating pin 6 extends beyond the distal opening 16 of outer sleeve 4 . Such extension can be effected by a single point of reciprocating pin 6 , or reciprocating pin 6 can be shaped to provide a plurality of points or otherwise configured to extend beyond distal opening 16 . Typically reciprocation pin 6 and distal tip 12 are unitary, but if desired they can be operably connected to provide the same functions (indeed, for example where the tip is designed to be used with a deep well plate such as certain 96-well plates, the distal tip may be configured to contact the side of the well as opposed to the bottom of the well yet still releasing the fluid at the desired point, for example substantially when the dispensing tip 2 contacts the bottom of the well (or other desired location).
[0048] The spot size can be controlled by a variety of factors in addition to the size of the reciprocating pin 6 in the outer sleeve 4 . For example, as depicted in FIG. 18, spot size can be affected by alcohol to water concentration, the concentration of cells, or other factors as desired. In view of the present application, a skilled person will be able to control the spot size quite precisely.
[0049] [0049]FIG. 4 depicts a hand-held embodiment of the microvolume liquid dispenser discussed herein. In particular, hand-held micropipette 32 has a handle 34 and a body 36 . As depicted, micropipette 32 additionally comprises a plunger 38 that is useful for typical operation of the micropipette but which is not necessary for the present systems for dispensing microvolumes of liquid.
[0050] [0050]FIG. 5 depicts a cytology microarray maker 40 having a frame 42 . As depicted, frame 42 is sized to be stationary and fit on a substantially flat surface although it can be configured or sized to fit any desired surface. Maker 42 has a first stage 44 second stage 46 and third stage 54 , each of which are capable of supporting or holding a cytology array template, cytology array substrate or other desired platform or surface. A cytology microarray template is a cytology microarray that comprises a plurality of liquid cytological specimens or other suitable samples (such as control samples or reference samples). This template can provide samples to the microvolume dispensing tips by transiently contacting the tips into the sample, i.e., the source of the liquid, and then suctioning up the liquid, for example by using capillary action, an active vacuum or otherwise as desired. It is an advantage of the present embodiment that enough liquid from the template can be loaded into the tips at one time to make a plurality of cytological microarrays without reloading. Accordingly, a plurality of different stains, probes or other investigative material can be used with different cytological microarrays but without significant variation in the samples in the microarrays, both in the volume of a given sample in the microarray and in the location of the samples in one microarray to another.
[0051] Cytology microarray maker 40 further comprises a body 36 that holds an array 26 of tips (see FIG. 6) between upright members 48 . Frame 42 further comprises at least one axial member 50 , which in the embodiment depicted comprises two rails 52 extending along frame 42 . In FIG. 5, rails 52 are attached to the frame via rail attachments 56 . Conversely, the rails 52 or other axial member 50 can be integrally formed in frame 42 , for example being formed by the provision of axial slots along frame 42 . Rails 52 , or other axial member, provide a track disposed along the frame such that the array of tips, the body, the upright members 48 , etc., are movable along the track between the various stages.
[0052] As depicted in FIG. 5, two sets of removable slide cards 47 are shown, one each above the first stage and second stage 46 . Upright members 48 , which as depicted are substantially planar elements 49 can be moved along frame 42 by pushing or pulling them along rails 52 . If desired, the positioning of the upright members 48 can be facilitated by the provision of retaining elements indicating when the upright members are in the proper location, for example by the provision of spring-loaded ball and indent centering and lock mechanisms, or any other desired positioning mechanism. The maker 40 in FIG. 5 also has a frame support 58 sized for a substantially planar surface.
[0053] [0053]FIG. 6 depicts a cytology microarray maker 40 comprising a body 36 holding an array of tips 26 and a cytology microarray template 60 . Upright members 48 comprise substantially planar elements 49 , which in turn comprise elongated axial channels 62 . Substantially planar elements 49 , are slidably connected to the rails 52 shown in FIG. 5, and are situated on either side of the stages. Elongated axial channels 62 provide locations configured to slidably receive projections 64 extending from body 36 . FIG. 6 also depicts a floating channel 66 in dotted line for one of the tips 2 ; similar floating channels are provided for each of the microvolume dispenser tips in array 26 but not depicted. The floating channels are each sized to releasably hold one tip. If desired, two or more of the channels can be interlocked, provided that adequate spacing between the tips is maintained when moving the array 26 from one stage to another. Also depicted are body biasing elements 68 which urge the body 35 away from the various stages. This facilitates both loading the tips and making the microarrays because one need merely push down on the body to load the tips/dispense from the tips; the tips then automatically reciprocate away from the given cytology element upon release of the pressure. As depicted, the various embodiments are used in an orientation where gravity is below the tips and assists in maintaining the tips in place in the body and in maintaining the fluid in the reservoirs. It is possible to provide other orientations for the various elements if desired. In addition, the body 36 moves in an orientation that is substantially normal to the various cytology templates/substrates. As used herein, substantially normal includes angles other than 90 degrees if desired by the user.
[0054] [0054]FIG. 7 depicts a tabletop 43 suitable for use with, and comprising a part of, frame 42 . In tabletop 43 as depicted, a variable Y adjustment device 70 and a variable X adjustment device at 74 are provided. Movement of these devices in the desired direction enhances the ability to precisely place templates and substrates under the body and array of tips. Also depicted are a plurality of cytological microarray substrates 76 , in this case glass slides.
[0055] FIGS. 8 - 11 provides photographs of a variety of arrays made using various dispensing tips. In each of FIGS. 8 - 11 , each of the spots provide a cytological specimen and has been stained with H & E. In FIGS. 8 and 9, the spots were made without using the reciprocating needle 6 discussed elsewhere and, as can be see, the spots are diffuse and large. In contrast, in FIGS. 10 and 11, medium and small spots were created using outer sleeves or funnels and reciprocating pins. Small pins and a high cell concentration solution were used to make medium spots in FIG. 10, and large pins and a high cell concentration solution were used to make small spots in FIG. 11.
[0056] [0056]FIGS. 12 and 13 provide photomicrographs at various magnifications (4×, 10× and 20×) of a single spot from the cytological microarrays depicted in FIGS. 8 and 11 respectively. As can be seen, the spots in FIG. 13 are smaller, as can also be seen in FIG. 11, and the cells are not as clustered and there is reduced overlapping. Thus the cells are better capable of analysis using certain analysis methods such as certain image cytometry analyses. FIG. 14 also depicts a series of micrographs of magnification 4×, 10× and 20× of a single spot from a hand spotted cytology microarray that was stained with H & E wherein the microvolume dispensing tip had a large reciprocating pin and a low cell concentration solution.
[0057] [0057]FIGS. 15 and 16 depict screen shots of cells images collected by an automated image cytometer. The Figures demonstrating the distribution of the images collected from the spots both with and without the cytological microvolume dispensing tip discussed herein. In FIG. 15, the spots were created using a funnel only, with out a reciprocating pin, whereas in FIG. 16 the spots were created using both the outer sleeve and the reciprocating pin (which was a small needle in this case). In each figure, low cell concentration solutions were used for the spots in the graphs on the left, high cell concentration solutions were used for the spots in the graphs on the right. As can be seen, the spots in FIG. 15 are significantly larger and the spots in FIG. 16 are better suited for some analyses than are the spots in FIG. 15.
[0058] [0058]FIG. 17 provides graphs depicting the distribution of cell images collected by an automated image cytometer wherein the spots were created using an outer sleeve only (on the left in each graph) and an outer sleeve with a small reciprocating pin (on the right in each graph). Two different cell concentrations were used for each pair in each graph, with low concentrations on the left and high concentrations on the right). The low cell concentrations, and the funnels without reciprocating pins created larger spots, with more cells imaged per spot. For the high cell concentration dispensed through a funnel with a reciprocating pin, the cell density was too high and it appears that the number of overlapping cell clusters artificially reduced the number of cells counted by the automated image cytometer. It appears that the cell concentration changes the viscosity of the solution and that the high concentration solution exhibits the characteristics of a viscous or slow spreading or rapidly evaporating solution.
[0059] In FIG. 18, different alcohol concentrations were used. As can be seen, increasing the alcohol concentration increased the spot size.
[0060] Turning to some additional discussion of various aspects, the amount of fluid deposited depends in part upon the shape of the outer sleeve and the shape of the reciprocating pin. The size to which the fluid spreads to create the spot depends in part on the suspension fluid, the type of planar surface, and the environment in which the process takes place. For example, low humidity, moderate temperature and a hydrophilic surface will cause the formation of a smaller spot than will high humidity, low temperature and a hydrophilic surface. Additionally, the suspension fluid may comprise rapidly drying fluids such as alcohol. The rate of spread of the fluid affects creation of a cellular monolayer. Too slow with the spreading and too fast with the evaporation with a high cell density will lead to many clumped, overlapping cells. Too fast with the spreading and too slow with evaporation will lead to larger than desired spots.
[0061] In addition to creating arrays of distinct spots on a planar surface, the same techniques and approach can be used to very rapidly turn a cell suspension into a spatially localized monolayer-type preparation for traditional cytological applications, as well as for automated quantitative cytological applications. This can be done by creating an area of spots that just touch or slightly overlap. These spots would be placed in an interleaved fashion such that new spots are either deposited on a virgin surface or adjacent to completely dry spots so as to create the optimal monolayer without causing all the deposited cells to bunch up along the edge or into clumps. The cytological preparation is typically disaggregated so as to not plug or clump up the outer sleeves or outer sleeve reciprocating pin combinations.
[0062] The outer sleeve or reciprocating pin outer sleeve combinations may also be used to disaggregate cytological samples by utilizing the shear forces involved in flowing the sample multiple times backwards and/or forwards through the outer sleeve or outer sleeve reciprocating pin combination. It is possible to create different controllable shear forces by varying the position of the reciprocating pin within the outer sleeve and by designing the shape of the reciprocating pin-outer sleeve contact areas appropriately.
[0063] The methodologies and systems herein can typically be implemented in parallel such that many (2 to 32 or more) spots could be deposited in parallel.
[0064] Applications for cytology microarrays in addition to those discussed elsewhere herein include 1) Use with multiple FISH probes where one probe is applied to a cytology microarray comprising samples from multiple subjects; 2) Use with multiple messenger RNA probes for expression analysis from multiple subjects; 3) Use with disease markers across multiple subjects or samples to reduce cost and/or increase throughput; 4) Use with an automated cytometry device to allow ploidy data to be rapidly collected from many samples/subjects disposed on a single slide, which can assist in reducing slide-to-slide staining variations.
[0065] The ability to make many equivalent cytology microarrays confers other possibilities. For example, given 200 tumor samples which need to be examined for about 1000 genetic changes or about 1000 expression changes, one can disaggregate the samples, create 200 cell suspensions, deposit 200 spots (one per sample) on each of 1000 slides (one spot from each sample for each slide, 100 cells per spot for a total cell count of about 100,000 cells) and then mark each slide with either a specific FISH probe (1 or multicolor per slide) or a specific mRNA marker for expression analysis. Thus, instead of running 600 DNA tissue microarrays, each of which typically uses about 1 million cells costs more per slide than cytology microarrays, one can run 1000 cytology microarrays for less cost, in some cases possibly about 10% the cost.
[0066] The data produced by each of the tissue microarray and the cytology microarray would be the about same except with the cytology microarray DNA data one would have FISH spot counts which can detect single deletions very reliably, as well as be able to differentiate the contamination cells (stromal, connective tissue, blood, vessel wall, etc.) from the tumor cells, which could reduce the need for tissue microdissection. The differentiation could be on the basis of morphological features or various counter stains. For the expression data, the result could be intensity expression for individual cells in a spot, the average expression, and the variance of expression. Given that mRNA marker and DNA FISH probe staining processes do not interact significantly it would be possible to perform both tests on the same samples.
[0067] Thus, in one aspect, one can match the FISH probe to the expression marker, or otherwise match gene and protein expression assays, and do both gene and gene expression at the same time. Also at a later date as more specific protein markers become available, one could measure all three of gene, gene expression and gene product on the same cells at the same time.
[0068] The present systems and methods are also useful for combining cytology microarrays (or for that matter, tissue microarrays) with complex liquid handling. For example, it would be possible to take multiple specimens from a single sample the deposit (or block) many spots of cells (or tissue cores) on a slide or slides and then deposit fixed (typically very small) amounts (usually no more than a single drop) of different marker solutions on different tissue or cell spots on the slide. This allows the different markers to bind the cell components (DNA, mRNA, etc.). The cell markers are then typically washed off the slide. To reduce the risk of cross contamination of marker solutions to adjacent spots, the small amounts of marker solution could be removed using a blotter (wicking material) in soft contact with the slide to wick away most of the marker solution then wash the slide. In all of these applications, a flexible automated cytometer (transmission and fluorescence mode) would be extremely valuable to automate the interpretation of the slides.
[0069] To reduce the spot to spot contamination (of either fluids and cells) it can be beneficial to use a slide with a removable or non-removable mask that creates shallow or deep wells, then depositing one spot into each well. The mask would contain the cell spot as well as any added solutions. For an example of a masked slide with removable mask see U.S. Pat. No. 5,784,193.
[0070] Turning to some additional discussion of the methods herein, in some aspects the methods comprising dispensing a microvolume of liquid. Such methods can comprise a) providing a microvolume liquid dispenser tip as discussed herein, b) transiently contacting the distal tip and distal opening with a substrate thereby causing the pin to cycle, for example by briefly touching the tip and the substrate; and, c) during the cycle, dispensing the liquid to the substrate.
[0071] The sleeve and pin can be configured to cooperatively dispense a volume per cycle suitable for a cytology microarray, and the passage can be sized to substantially avoid clogging by the cells. The microvolume liquid dispenser tip can be one of an array of tips, the tips and array configured and sized to make a cytology microarray. The method can comprise substantially simultaneously transiently contacting the array of tips with a cytology microarray platform, thereby causing the pin to cycle, and thereby forming the cytology microarray on the platform.
[0072] The methods can also make cytology microarrays. Such methods can comprise providing a frame holding a body holding an array of microvolume liquid dispenser tips, at least first and second stages sized to support cytology microarrays, upright members operably attached to the body to move the body and tips substantially normal to the stages between at least an extended position wherein the tips contact a cytology microarray substrate located on the stage and a retracted position wherein the tips do not contact the cytology microarray substrate, and at least one axial member disposed along the frame and to move the upright members between the stages. The first stage holds a cytology microarray template comprising an array of liquid cytological specimens and the second stage holds a cytology microarray substrate. The tips in the array are then loaded with the liquid cytological specimens by transiently moving the array of tips into the liquid cytological specimens and suctioning up the liquid cytological specimens using capillary action. Next, the array of tips is moved to the second stage, where the cytology array is made by transiently contacting the array of tips with the cytology microarray substrate.
[0073] The frame can further comprises a third stage holding a cytology microarray substrate and a second cytology array can be made by moving the array to the third stage then transiently contacting the array of tips with the second cytology microarray substrate. In some embodiments, this can be done without reloading the tips. Additionally, the substrates and the template(s) can be removed or covered, then additional substrates can be provided and additional cytology arrays created. The method can further comprise adjusting the stages on at least one of an x-axis and a y-axis relative to at least one of the frame and each other. The methods can also comprise placing the tips in the body to create the array of tips and removing the tips from the body after making the cytology array. As with the devices herein, the methods can be either substantially manual or automated. If automated, the devices can be operably connected to a controller, which is a device that is capable of controlling various elements of the apparatus and methods discussed herein. For example, the controller can control the location and movement of the body, the loading of and dispensing from the tips, and the collection of images form a microarray. Typically, a controller is a computer or other device comprising a central processing unit (CPU) or other logic-implementation device, for example a stand alone computer such as a desk top or laptop computer, a computer with peripherals, a local or internet network, etc. Controllers are well known and selection of a desirable controller for a particular aspect or feature is within the scope of a skilled person in view of the present disclosure.
[0074] All terms used herein, including those specifically discussed below in this section, are used in accordance with their ordinary meanings unless the context or definition clearly indicates otherwise. Also unless indicated otherwise, except within the claims, the use of “or” includes “and” and vice-versa. Non-limiting terms are not to be construed as limiting unless expressly stated, or the context clearly indicates, otherwise (for example, “including,” “having,” and “comprising” typically indicate “including without limitation”). Singular forms, including in the claims, such as “a,” “an,” and “the” include the plural (for example, “a” means “at least one”) unless expressly stated, or the context clearly indicates, otherwise.
[0075] The scope of the present disclosure includes both means plus function and step plus function concepts. However, the terms set forth in this application are not to be interpreted in the claims as indicating a “means plus function” relationship unless the word “means” is specifically recited in a claim, and are to be interpreted in the claims as indicating a “means plus function” relationship where the word “means” is specifically recited in a claim. Similarly, the terms set forth in this application are not to be interpreted in method or process claims as indicating a “step plus function” relationship unless the word “step” is specifically recited in the claims, and are to be interpreted in the claims as indicating a “step plus function” relationship where the word “step” is specifically recited in a claim.
[0076] From the foregoing, it will be appreciated that, although specific embodiments have been discussed herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the present disclosure. Accordingly, the disclosure includes such modifications as well as all permutations and combinations of the subject matter set forth herein and is not limited except as by the appended claims.
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Microvolume liquid dispensers that provide simple and inexpensive approaches to making cytology microarrays. In some embodiments, the dispensers comprise tips that comprise an outer sleeve, typically shaped like a funnel, that holds a reciprocating needle or pin. The tip of the pin slightly extends beyond the distal opening of the outer sleeve in one position, and is retracted in another position. When the pin is in the distal position the pin contacts the inner surfaces of the sleeve and blocks cytology liquid from flowing through the opening of the sleeve. Thus the pin and sleeve cooperate to form a reservoir behind the blockage. When the pin is pushed up into the sleeve, for example by touching the tip to a glass slide, a passage is formed between the outer surface of the pin and the inner surface of the sleeve. The liquid in the reservoir then flows through the passage and onto the slide. Removing the tip from the substrate moves the pin back to its original position, reforming the reservoir and leaving a predetermined microvolume amount of the liquid on the slide.
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CROSS REFERENCE TO PENDING APPLICATION
This is a continuation of pending International application PCT/EP99/08436 filed on Nov. 4, 1999, which designates the United States and claims priority of German patent application DE 198 59 731 filed on Dec. 23, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an articulated arm for an awning, comprising a first arm part and at least a second arm part, wherein the first arm part and the second arm part are connected with each other via an articulation, the articulation axis of which runs transversely to the longitudinal axis of the arm parts, and wherein, in the first arm part, at least two springs adjacent to each other are arranged, with one end of the springs being fixed on the first arm part, and on the other end of the springs at least one flexible traction element is fixed which is led via the articulation into the second arm part, where it is fixed on the second arm part.
2. Description of the Related Art
One type of articulated arm is generally known from European patent number EP 0 489 186 A1. The articulated arm mentioned is used in a certain type of awnings, in so-called articulated arm or folding-arm awnings. Such awnings have an awning fabric, which is held upon a fabric winding spindle in such a way that it can be wound up and wound off. A forward end of the awning fabric is fixed on an extension bar, which is moved away from the fabric winding spindle, if the awning fabric is wound off the fabric winding spindle, and which is moved towards the same when the awning fabric is wound up. The extension bar on which the forward end of the awning fabric is fixed is, at the same time, over the at least one, usually two articulated arms, connected to a supporting part of the awning, e.g. a support tube.
Such an articulated arm typically has at least two arm parts which are connected with each other via an articulation, the axis of which runs transversely to the longitudinal axis of the arm parts. One arm part, which is generally designated as the upper arm is, at the same time, connected in an articulated way with its end facing away from the articulation to the supporting part of the awning, i.e. the support tube. The other arm part, which is generally designated as the forearm is, with its end facing away from the articulation, connected to the extension bar in an articulated way.
When the awning is completely reeled in, wherein the awning fabric is completely wound up on the fabric winding spindle, the articulated arm is bent to its maximum, i.e. the first and the second arm part are nearly parallel and adjacent to each other and run approximately parallel with the extension bar and the support tube. When the awning is reeled out to its maximum extent, i.e. if the awning fabric is completely wound off the fabric winding spindle, the articulated arm is stretched.
The articulated arm or the articulated arms of the awning have the function to push away the extension bar, when the awning fabric is wound off the fabric winding spindle, in order to pull away the fabric under tension when it is wound off the fabric winding spindle. For that purpose, in one of the arm parts, e.g. in the upper arm of the articulated arm, at least one spring is arranged, the one end of which is fixed to the first arm part, and to the other end of which an end of at least one flexible traction element is fixed, e.g. in the shape of a wire cable or a chain, which is led over the articulation that connects the two arm parts into the second arm part, where it is fixed with its other end onto the second arm part.
When the awning is reeled in and the articulated arm is bent to its maximum, the spring, which is usually designed as a tension spring, is stretched to its maximum. When the articulated arm is bent, the distance length between the fixation point of the traction element on the forearm and the fixation point of the spring on the upper arm is, namely, enlarged by the curve length of the bent articulation. The spring is, thus, when the articulated arm is bent, stretched to its maximum, so that the bent articulated arm is pre-stretched in its stretched position, with the effect that the articulated arm, when the fabric is wound off, stretches on his own.
In order to pre-stretch the articulated arm even in an awning with a relatively high extension length correspondingly in its stretched position, high spring forces are often required. The springs used have, thus, a very high spring constant. In awnings with high extension length, moreover, at least two springs or even more springs are used, which are adjacently arranged in the one arm part.
In these articulated arms, the at least two springs are typically connected with each other, on their free end, by means of a brace, wherein one single suspension is arranged on the brace, e.g. in the shape of a hook, on which, then, one single traction element is commonly fastened. The traction element, thus, has to take up the force of two or more springs. The traction element is, correspondingly, much more stressed as if it was connected to only one spring. This may result in reduction of the endurance of the traction element, i.e. the durability under load of the traction element is reduced when the awning is reeled in and reeled out. The traction element is exposed to repeated alternating stress, in particular in the region of the articulation, where it experiences a deflection, so that the one traction element can tear earlier.
It has therefore been suggested to use, instead of one traction element, a string of several traction elements, which are tied together on their one end, which is connected to the end of the springs. In this way, however, again only one fixing point of all traction elements with all springs is created. In other words, again only a simple connection between the bunched end of the traction elements and the collected end of the springs exists, which, again, are exposed to higher stress. If this fixing point tears off during operating the awning, there is no connection anymore between the traction elements and the springs, and the function of the articulated arm is compromised. European patent EP 0 489 186 A1 discloses a similar articulated arm comprising two parallel chains as traction elements which are individually connected to the two springs, respectively.
Therefore, it is an object of the present invention to provide an improved articulated arm that can longer resist the repeated alternating stress when the awning is reeled in and out without suffering damage.
SUMMARY OF THE INVENTION
According to one aspect of the invention, this object is achieved by an articulated arm for an awning, comprising a first arm part and at least a second arm part each having a longitudinal axis, an articulation having an articulation axis, the first arm part and the second arm part being connected to each other via the articulation, and the articulation axis running transversely to the longitudinal axes of the arm parts, at least two springs arranged adjacent to each other and each of the springs having a first end and a second end, the first ends being fixed at the first arm part, at least two traction elements each having a first end and a second end, the first ends being individually connected to the second ends of the springs, and the traction elements being led via the articulation to the second arm part and fixed thereto, wherein at least one traction element is assigned to each spring and wherein the traction elements are wire cables, which comprise, at least in their region which is led via the articulation, a plastic coat.
In this aspect, instead of fixing one single traction element with its end together onto the at least two springs, or instead of bunching several traction elements on one end and then, bunched, connecting with all springs together, it is provided, according to the invention, to assign to each existing spring at least one separate traction element, which is, then, fixed only onto the spring that is assigned to it. Each traction element, therefore, has to take up the force of only one spring, which reduces the stress of each individual traction element. Further, instead of using chains as traction elements, the traction elements are wire cables having a plastic coat at least in the region of the articulation. The plastic coat advantageously reduces friction and wear of the wire cables in the region of the articulation. Durability under load tests have shown that the endurance of the articulated arm according to the invention in comparison with known articulated arms is by far higher even than the endurance of articulated arms using chains.
Another advantage of this embodiment of the articulated arm of the invention is that, should one traction element tear, the at least one further traction element and the at least one further spring are still connected, so that the function of the articulated arm is at least partly maintained, and that then the connection still existing of the remaining traction element with the remaining spring is exposed to no higher stress than if all traction element spring connections were intact. This object of the invention is in that way completely achieved.
In another aspect, the traction element assigned to the corresponding spring is fixed, with its second end, individually on the second arm part. By this measure, the operational safety of the articulated arm is increased even further, as in this embodiment both ends of the traction element are fixed individually both to the assigned spring and to the fixation point on the second arm. Alternatively, however, if the traction elements are bundled, on their end fixed on the second arm part to one end, and the bundled end is fixed on the second arm part, the collection or bundling of the ends fixed onto the second arm part, which are still fixed individually on each spring, has the advantage that the traction elements can more easily be fixed when the articulated arm is mounted, since, then, only one end has to be fixed onto the second arm part.
In a further aspect, the springs are coil springs and an insert nut is fixed on at least one end of these springs, respectively, into which a suspension eyelet is screwed. This configuration of the springs also contributes to higher endurances of the articulated arm. In usual articulated arms, namely, coil springs are generally used, the ends of which are formed into a hook. Forming of a coil spring end into a hook leads, however, to material weakening and earlier material fatigue of the springs in the region of the hook-shaped formed ends.
By fixing an insert nut onto at least one end of the springs, as it is provided according to this aspect of the invention, into which a suspension eyelet is screwed, a fixation point for the traction element or for the fixation of the spring on the first arm part is created, which eliminates the need for the spring being formed and, thus, from experiencing material fatigue. It is then preferred if the insert nuts are rolled or pressed into the spring. By this measure, a particularly tight connection that can resist high stress is created between the insert nut and the spring.
In yet another aspect, at least two traction elements are assigned to each spring. In this embodiment, the at least two traction elements are preferably, according to the invention, individually fixed onto the spring assigned to them. By assigning at least two traction elements per spring, the endurance of the articulated arm can be increased even further.
Further advantages can be taken from the description and the enclosed drawings. It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention is shown in the drawings and will be explained in more detail in the description below. In the drawings:
FIG. 1 shows a schematic perspective presentation in total of an awning; and
FIGS. 2A and 2B shows an articulated arm according to the invention in two partial pictures, partly in longitudinal section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made to the drawings wherein like numerals refer to like parts throughout. In FIG. 1, one embodiment of an awning designated with the general reference number 10 is shown, partly in a discontinuous way. Awning 10 is used for shading terraces and the like. Awning 10 has a support tube 12 , which is used as supporting part of awning 10 , and via which awning 10 is fixed by means of wall consoles 14 onto a building wall (not shown). Wall consoles 14 are, on one side, fixed onto the support tube 12 and have fixation portions for fixing on the building wall, which are not shown in detail but is performed in a manner well understood by one of ordinary skill in the art.
Awning 10 has further an awning fabric 16 (shown in ghost view if FIG. 1 ), which can be wound up and wound off of fabric winding spindle 18 , which is represented with broken lines. For that purpose, fabric winding spindle 18 is in connection with a gear, which is not shown in detail, on one end of fabric winding spindle 18 , which can be manually driven by a crank handle, or is alternatively driven via an electric motor. Fabric winding spindle 18 can be driven via the gear in two senses of rotation around its longitudinal axis.
Fabric winding spindle 18 is, except a front slot 19 running parallel to fabric winding spindle 18 , surrounded about its circumference by a sleeve 20 , which protects the fabric 16 being wound onto fabric winding spindle 18 from detrimental environmental influences. Sleeve 20 is retained, on both ends, by means of side parts 22 fixed onto support tube 12 .
Awning 10 further has an articulated arm 24 and another articulated arm 26 , articulated arm 26 and articulated arm 24 being designed, in this embodiment, identically to each other and being arranged substantially mirror-symmetrically to each other, so that in the following only articulated arm 24 will be further described. It should be understood that the description of a single articulated arm 24 that follows refers equally to multiple articulated arms 24 , 26 .
Articulated arm 24 has a first arm part 28 , which is also designated as upper arm. Articulated arm 24 further has a second arm part 30 , which is also designated as forearm. First arm part 28 and second arm part 30 are articulatedly connected with each other via an articulation 32 , whereby a rotational axis of articulation 32 runs transversely to the longitudinal direction of first arm part 28 and/or to the longitudinal direction of second arm part 30 .
First arm part 28 is connected, with its end 34 facing away from articulation 32 , over a supporting trestle 36 , with support tube 12 . First arm part 28 is, therewith, articulatedly connected to supporting trestle 36 . Second arm part 30 is connected, articulatedly, with its end 38 facing away from articulation 32 with an extension bar 40 .
One function of articulated arm 24 and also of articulated arm 26 is to locate extension bar 40 , and, when awning fabric 16 is wound off, to push extension bar 40 away from fabric winding spindle 18 . When awning fabric 16 is completely wound up on fabric winding spindle 18 , extension bar 40 rests closely adjacent slot 19 of sleeve 20 . Articulated arm 24 and articulated arm 26 are then bent to their maximum extents, i.e. first arm part 28 and second arm part 30 extend approximately parallel to support tube 12 , i.e. first arm part 28 and second arm part 30 are folded together around articulation 32 . The same applies for articulated arm 26 .
Proceeding from this state reeled-in to its maximum, awning fabric 16 can be wound off by turning fabric winding spindle 18 , whereby articulated arms 24 and 26 have the function to push extension bar 40 away from fabric winding spindle 18 and to pull away awning fabric 16 wound off under stress from fabric winding spindle 18 , so as to inhibit sag of the awning fabric 16 . To fulfill this function, articulated arm 24 is prestressed from the maximally bent into the stretched position by adding spring force. This is described in the following with reference to FIGS. 2A and 2B.
FIGS. 2A and 2B show articulated arm 24 in total in two section, broken views. The right end in FIG. 2B adjoins, correspondingly, to the left end in FIG. 2 A. According to FIG. 2A, first arm part 28 is formed by a tubular member 42 .
At a first end 34 of first arm part 28 , a fork 44 is mounted onto tubular member 42 , which is connected with supporting trestle 36 in an articulated way according to FIG. 1 . Fork 44 has, through it, a continuous bore 46 , through which a pivot pin (not shown) can be put, which produces the articulated connection with supporting trestle 36 in a well understood manner.
Fork 44 also has a block-like extension 48 , which encloses end 34 of first arm part 28 and projects partly into tubular member 42 . Onto extension 48 , in this embodiment, three suspensions 50 a-c in the shape of crooked hooks are fixed.
In tubular member 42 , in this embodiment, three springs 52 a-c are arranged adjacent to each other. Springs 52 a-c, in this embodiment, are designed in the shape of coil springs and act as tension springs, i.e. in a force-free state, springs 52 a-c are pulled together to their maximum and can be stretched by tension in their longitudinal direction. Onto respective first ends 54 a-c of springs 52 a-c, an insert nut 56 a-c is fixed, respectively. Insert nuts 56 a-c are rolled or pressed onto the respective end 54 a-c and extend to e.g. some windings into the ends 54 a-d of springs 52 a-c. In addition, the insert nuts 56 a-c in springs 52 a-c can be welded with the same. In insert nuts 56 a-c, a respective suspension eyelet 58 a-c, which are designed in this embodiment as closed ring eyelets, is affixed to. In suspension eyelets 58 a-c, the respective hook of suspensions 50 a-c is hooked into.
Each of springs 52 a-c is, thus, individually fixed onto first arm part 28 , more exactly, onto extension 48 . Each of springs 52 a-c is associated with a traction element 60 a-c. In that way, each traction element 60 a-c is, individually, firmly connected to a respective second end 62 a-c of its associated spring 52 a-c.
In order to fix traction elements 60 a-c insert nuts 64 a-c are firmly connected with second ends 62 a-c respectively. In insert nuts 64 a-c suspension eyelets 66 a-c are screwed into, which are designed in the shape of ring eyelets. A respective first end 68 a-c is respectively laid to a loop 70 a-c, which grips through the respectively assigned suspension eyelet 66 a-c and is thus firmly connected to the latter. Loops 70 a-c are, by means of a squeezing device or a squeezing ring, fixed in an undetachable way. First ends 68 a-c are still, in first arm part 28 , positioned within tubular member 42 .
According to FIG. 2B, on first arm part 28 adjacent end 72 of the first arm part 28 , again, a fork 74 is firmly connected with tubular member 42 . Fork 74 forms a first part of articulation 32 , via which first arm part 28 is articulatedly connected with second arm part 30 . Second arm part 30 is also formed by a tubular member 76 , at a first end 35 of which facing articulation 32 , a block 78 is firmly connected with the tubular member 76 , wherein block 78 engages with an extension 80 into fork 74 . A pivot pin 82 indicated with broken lines passes through fork 74 and extension 80 of block 78 .
Traction elements 60 a-c are led over articulation 32 , more exactly, over fork 74 , extension 80 of block 78 and block 78 itself into tubular member 76 of second arm part 30 . On extension 80 or block 78 , traction elements 60 a-c rest. A respective second end 82 a-c of traction elements 60 a-c is respectively individually connected with second arm part 30 , for the sake of which a slot 84 a-c is provided in block 78 for each end 82 a-c, respectively, in which the respective end 82 a-c is secured into and, via tubular member 76 , is connected with block 78 in such a way that it resists extension. Ends 82 a-c are in this connection, again, laid into loops, which, by means of a squeezing device or a ring, are secured against detaching.
In an alternative embodiment, instead of fixing ends 82 a-c individually in block 78 , for the sake of which three slots 84 a-c are provided, it can also be provided to collect ends 82 a-c to one single end, e.g. by bunching or bundling by means of a squeezing device or a squeezing ring, and then attach this collected end onto block 78 , for the sake of which only one of the slots 84 a-c needs to be there.
On end 38 of second arm part 30 , a fixation element 86 is arranged, over which second arm part 30 is connected, articulatedly, with extension bar 40 according to FIG. 1 . Traction elements 60 a-c are flexible, so that they can adjust, in the region of articulation 32 , when articulated arm 24 is bent, to the curved transition from first arm part 28 to second arm part 30 , and are substantially unextensible, so that they can transmit tensile forces. When articulated arm 24 is bent, springs 52 a-c, due to the increasing distance length, which overstrain traction elements 60 a-c in the region of articulation 32 , are strained and, thus stressed.
It can be seen from FIGS. 2A and 2B that each traction element 60 a-c with its corresponding spring 52 a-c forms an individual force transmitting system which is independent of other traction elements 60 a-c and other springs 52 a-c. If there is, for example, a rupture of traction element 60 a, force transmitting systems from traction elements 60 b, 60 c and respective springs 52 b, 52 c remain intact, so that articulated arm 24 remains operative, although with reduced tension force.
Traction elements 60 a-c in this embodiment are designed as wire cables, which have, at least in the region of articulation 32 , in which traction elements 60 a-c rest upon extension 80 of block 78 , a plastic coat. Friction of traction elements 60 a-c on extension 80 is thereby reduced.
In the embodiment shown, each spring 52 a-c is assigned with a traction element 60 a-c. It can also be provided to assign to each spring 52 a-c two or more traction elements 60 a-c, whereby each force transmitting system formed in that way is designed independently from the other force transmitting systems.
While the embodiment shown has three springs 52 a-c, it is also possible, in the scope of the invention, to provide an articulated arm with two springs or four or more springs. In the scope of the invention, it is also possible to connect ends 62 a-c of springs 52 a-c with each other, whereby a brace used for it has suspensions in corresponding number, in order to be able to suspend these individually. It will also be appreciated that additional articulated arms 24 , 26 can be included for an awning 10 of greater width.
Although the foregoing description of the preferred embodiment of the present invention has shown, described, and pointed out the fundamental novel features of the invention, it will be understood that various omissions, substitutions, and changes in the form of the detail of the apparatus as illustrated as well as the uses thereof, may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the present invention should not be limited to the foregoing discussions, but should be defined by the appended claims.
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An articulated arm for an awning such as for a patio or deck including at least first and second arm parts joined by an articulation. Longitudinal axes of the arm parts are orthogonal to the articulation axis. The articulated arm also includes at least two springs arranged adjacent each other and first ends of the springs are fixed to the first arm part. At least two traction elements are also and are individually connected to second ends of the springs. The traction elements are led via the articulation to the second arm part and are fixed thereto. The traction elements are wire cables which include a plastic coat in at least a region adjacent the articulation.
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This is a division of application Ser. No. 735,865, filed Oct. 27, 1976, now U.S. Pat. No. 4,091,044.
BACKGROUND OF THE INVENTION
The present invention relates to the production of 1,2-diphenylethylene (stilbene) and derivatives thereof.
Stilbene, because of its unsaturated character, is very reactive and may be employed in various organic syntheses. It is useful in the production of products which may be used in the manufacture of dyes, paints and resins. It is also useful in optical brighteners, in pharmaceuticals and as an organic intermediate.
Heretofore, stilbene has not been available in commercial quantities because the attendant yields of the known processes for the manufacture of stilbene have been generally small. Stilbene has been synthesized by dehydrogenation of bibenzyl; by dehydrogenation of 1,2-bis(3-cyclohexen-1-yl)ethylene (U.S. Pat. No. 3,387,050); and by reacting a benzyl mercaptan with a sulfactive catalyst, for example, molybdenum disulfide and copper sulfide (U.S. Pat. No. 2,645,671). Stilbene and halostilbenes have been synthesized by the iodative dehydrocoupling of toluene and halogen-substituted toluenes with elemental iodine and molten lithium iodide at toluene conversions of 10-30% (U.S. Pat. No. 3,409,680).
In U.S. Pat. No. 3,205,280, a catalytic dehydrogenation process is disclosed wherein certain hydrocarbons are converted to less saturated hydrocarbons by heating a mixture of hydrocarbon with at least 0.001 mol of a halogen per mol of hydrocarbon in the presence of free oxygen and a solid catalyst of an alkali metal halide and silver halide and additionally oxides and halides of certain elements.
In U.S. Pat. No. 3,694,518, a dehydrocoupling process is disclosed wherein toluene is converted to stilbene by heating toluene with oxygen in the presence of iodine and, optionally, an inert heat carrier material. In U.S. Pat. No. 3,868,427 this process of dehydrocoupling is carried out in the presence of a metal oxide, preferably palladium oxide coated on alpha-alumina.
Dehydrocoupling of toluene by the reaction with lead oxide to form stilbene has been reported by Behr and Van Dorp, Chem. Ber. 6,753 (1873) and Lorenz, Chem. Ber. 7,1096 (1874). In this reported work, stilbene is obtained by conveying toluene over lead oxide maintained at or about at a dark red glow. More recent disclosures of the metal oxide-toluene reaction are given in U.S. Pat. No. 3,476,747 and U.S. Pat. No. 3,494,956. The former patent relates to preparation of 1,2-bis(aryl)ethylenes by contacting of an aryl methane such as toluene with an inorganic oxidant from the group of arsenic pentoxide, antimony pentoxide, bismuth trioxide, manganese arsenate, or antimony tetraoxide at elevated temperatures. In Example 9 of U.S. Pat. No. 3,494,956, it is reported that a mixture of toluene and oxygen passed over heated lead oxide produces bibenzyl. In another patent, U.S. Pat. No. 3,557,235, it is reported that toluene can be oxidatively coupled in a stoichiometric reaction where a metal oxide, such as lead oxide, serves as a source of oxygen in the reaction.
SUMMARY OF THE INVENTION
This invention is directed to an improved dehydrocoupling process for converting toluene and toluene derivatives to stilbene and stilbene derivatives. Accordingly, typical objects of the invention are to provide an improved one-step, vapor-phase process for the production of stilbene and derivatives thereof and to provide a vapor-phase dehydrocoupling process for converting toluene and toluene derivatives to stilbene and stilbene derivatives characterized by high toluene conversion and high stilbene selectivity.
Other objects, aspects and advantages of the invention will become apparent to those skilled in the art upon further study of the disclosure and the appended claims.
In accordance with the invention, toluene and toluene derivatives are oxidatively dehydrocoupled to produce stilbene and stilbene derivatives by heating the toluene or toluene derivatives in the vapor phase in contact with a metal- and oxygen-containing composition which functions as an oxidant or oxygen carrier or as a catalyst, said composition having the following empirical formula
Sb.sub.a Pb.sub.b Bi.sub.c O.sub.d
wherein a is 1, b is 0.2-10, c is 0-5 and d is a number taken to satisfy the average valences of the Sb, Pb and Bi in the oxidation states in which they exist in the oxidant or catalyst. Preferred compositions are those defined by the formula
Sb.sub.a Pb.sub.b Bi.sub.c O.sub.d
wherein a is 1, b is 0.5-5, c is 0-1 and d is a number taken to satisfy the average valences of the Sb, Pb and Bi in the oxidation states in which they exist in the oxidant or catalyst. The metals are in combination with oxygen and may exist as individual oxides or as complexes of two or more of the metals and oxygen or as a combination of oxides and complexes. The reduced form of the oxidant remaining after the reaction can be regenerated by air oxidation in the absence of the hydrocarbon and reused.
The same metal- and oxygen-containing composition described above can be employed as a catalyst for the conversion of toluene and toluene derivatives to stilbene and stilbene derivatives. When operating in the catalytic mode, the hydrocarbon together with oxygen is heated in the vapor phase in contact with the metal- and oxygen-containing composition described above.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process of the invention is conveniently carried out in an apparatus of the type suitable for carrying out chemical reactions in the vapor phase. It can be conducted in a single reactor or in multiple reactors using either a fixed bed, a moving bed or a fluidized bed system to effect contacting of the reactant or reactants and oxidant or catalyst. The reactant toluene or toluene derivative will generally be heated and introduced into the reactor as a vapor. However, the reactant may be introduced to the reactor as a liquid and then vaporized.
The temperature range under which the reaction can be carried out extends from about 500° C. to about 650° C. preferably from about 540° to about 600° C. Pressure is not critical and the reaction may be carried out at subatmospheric, atmospheric or superatmospheric pressure as desired.
The contact time of the reactant hydrocarbon and the oxidant or catalyst in the reactor may vary depending upon the reaction temperature and the desired toluene conversion level. At higher temperatures and lower toluene conversion levels, shorter contact times are required. Generally, the contact time will vary from about 0.5 second to about 5 seconds. Preferably, for optimum conversion and selectivity in the preferred temperature range, a contact time from about 2 sec. to about 4 sec. is employed.
In addition to the toluene and/or toluene derivatives, other inert substances such as nitrogen, helium, and the like may be present in the reactor. Such inert materials may be introduced to the process alone or may be combined with the other materials as feed. Water or steam may be added to the reaction zone preferably being introduced with the feed in order to improve the selectivity to the desired products and particularly to suppress complete oxidation to CO 2 . Steam-to-hydrocarbon ratios in the range from 0.5 to 10 or more are suitable, the upper limit being determined by practical cost considerations. Ratios in the range from 1 to 3 are preferred.
The reaction may be conducted in the presence or absence of added free oxygen. When oxygen is not fed with the hydrocarbon, the oxygen required for the reaction is provided by the metal- and oxygen-containing composition which enters into the reaction and is consequently reduced during the course of the reaction. This necessitates regeneration or re-oxidation which can be easily effected by heating the material in air or oxygen at temperatures from about 500° to about 650° C. for a period of time ranging from about 30 min. to about one hour. In a semi-continuous operation, regeneration can be effected by periodic interruption of the reaction for re-oxidation of the metal- and oxygen-containing composition, i.e., periods of reaction are cycled with periods of regeneration. Operation, however, can be on a continuous basis whereby a portion of the metal- and oxygen-containing composition can be continuously or intermittently removed, re-oxidized and the re-oxidized material can thereafter be continuously or intermittently returned to the reaction. The latter method is particularly adapted to operations in which the metal- and oxygen-containing composition is fed in the form of a fluidized bed or a moving bed system.
When oxygen is employed as a reactant, sufficient oxygen is used to provide a hydrocarbon-to-oxygen mol ratio from about 1 to about 8 and preferably from about 2 to about 6. The oxygen may be supplied either as free oxygen or as an oxygen-containing gas such as air.
Suitable oxidants or catalysts can be prepared in several ways. The simplest method involves adding the metal oxides to water with stirring, heating the mixture to evaporate the water, drying and calcining. In another method of preparation, the powdered metal oxides can be intimately mixed before forming a paste of them with water and further mixing said paste. The paste can be spread and dried in air, after which it can be calcined in air. The calcined product can then be crushed and sieved to the desired mesh size. Alternatively, the metal oxides can be mixed dry together with a material which facilitates forming the mixture into pellets and then pressed to form pellets which are calcined prior to use.
The oxidant or catalyst may be employed alone or with a support. Suitable supports, for example, include silica, alumina, silica-alumina, metal aluminates such as magnesium aluminate and the like.
Temperatures employed for calcination of the metal- and oxygen-containing compositions may vary from about 400° to about 1200° C. The higher temperatures from about 900° to 1100° C. result in higher selectivity with some loss in activity. Preferred calcination temperatures, therefore, lie in the range from about 700° to about 1000° C. Calcination times may vary from about one to about six hours and preferably from about two to about four hours at the higher temperatures. The surface area of the oxidant or catalyst is not critical and may vary from about 0.1 m 2 /g to about 5.0 m 2 /g.
The invention is illustrated in the following examples which, however, are not to be considered as limiting it in any manner whatsoever.
EXAMPLE 1
An oxidant was prepared by adding 58.3 g of antimony trioxide (Sb 2 O 3 ) and 134 g of litharge (Pbo) to 250 ml of water with stirring. This mixture was heated to evaporate the water and the resulting solid was dried in an oven at 110° C. overnight. A portion of the solid was calcined at 400° C. for 1 hr, then at 600° C. for 4 hr. and finally at 950° C. for 3 hr. The final product had an Sb/Pb atomic ratio of 1:1.5.
A stainless steel tube 1/2 in. in diameter and about 10 inches long was employed as a reactor for the toluene conversion reaction. It was equipped at the upper end with inlet means for introducing the reactant and at the bottom with outlet means for collection of the reaction effluent or for introducing it into a gas chromatograph for analysis. A charge of approximately 25 g of the oxidant described in the preceding paragraph was contained in the reactor being held in place with a coarse stainless steel frit at each end. In a series of runs, steam and toluene in a 1:1 mol ratio were fed to the reactor maintained at a pressure of 745 mm Hg and 560° C. at such a rate as to provide a 4-second residence time of toluene therein and a reaction period of about one minute. Between runs the oxidant was regenerated by passing air through it at a temperature of 560° C. for a period from about 30 to 60 minutes. Results of the runs in terms of toluene reacted (conversion) and the amount of the toluene reacted converted to stilbene (stilbene selectivity) are presented in Table 1 below.
Table 1______________________________________Run No. 1 2 3 4______________________________________Conversion, % 53.1 41.0 37.0 36.9Selectivity, % cis-stilbene 6.8 6.8 6.8 6.8 trans-stilbene 58.9 58.3 58.5 57.9 Bibenzyl 5.0 7.3 7.7 8.4 Benzene 17.5 16.3 16.1 16.1 CO.sub.2 1.7 1.5 1.3 1.5______________________________________
EXAMPLE 2
A series of oxidants having Sb/Pb atomic ratios of 1 to 5 were prepared for testing as oxidants in the dehydrocoupling of toluene to produce stilbene. Powdered lead oxide (PbO) and antimony oxide (SbO 3 ) were intimately mixed and a paste was formed of the mixture with distilled water which was also thoroughly mixed. The paste was spread to a depth of about 4 mm in a pan and dried in air on a hot plate at about 150° C. The very soft cake was transferred to an Alundum crucible and calcined in air for two hours at 600° C. After calcination, the very hard composition was crushed in a mortar and then sieved to 4 to 30 mesh size before evaluation.
A series of runs was conducted in which toluene was dehydrocoupled at a temperature of 560° C., a steam/toluene mol ratio of 2.0 and a contact time of 4.23 seconds using lead oxide (Run No. 1) and the various oxidants prepared as described above. The reactor employed was essentially the same as that in Example 1 except that it contained a concentric thermocouple. About 18 ml (˜25 g) of the oxidant was contained in the reactor. Toluene and steam were metered into the inlet system through flash vaporizers using syringe pumps and passed through the oxidant in the reactor over a period of about 3 minutes. The reaction effluent was introduced into a gas chromatograph for analysis. Results are presented in Table 2 below. All tabulated results are averages of duplicate runs.
Table 2______________________________________Run No. 1 2 3 4 5 6 7______________________________________Sb/Pb, Atomic 0 1:1 1:1.25 1:1.5 1:2 1:2.5 1:5Surface area, 0.13 0.37 0.60 -- 0.25 0.21 0.39 m.sup.2 /gConversion, % 22.5 17.6 50.3 70.8 71.0 79.0 51.1Selectivity, % cis-stilbene 7.1 2.3 3.8 3.8 3.7 2.5 5.6 trans-stilbene 61.1 19.3 32.6 32.3 28.5 21.7 48.3 Bibenzyl 7.6 23.9 8.2 2.2 3.0 1.7 5.8 Benzene 16.1 34.7 33 44.6 44.0 48.5 17.7 CO.sub.2 1 9.7 8.5 5.4 9.6 14.9 12.5______________________________________
EXAMPLE 3
An oxidant having a Sb/Pb atomic ratio of 1:2 and a surface area of 0.37 m 2 /g was prepared as described in Example 2 above and recalcined at 900° C. for 3 hours. This oxidant was charged to the same reactor used in Example 2 and a series of runs were made in which steam and toluene (2:1) were contacted with the oxidant in the reactor over a 3-minute reaction period and the reaction effluent was analyzed by gas chromatographic means. Reaction conditions and results are presented in Table 3 below.
Table 3__________________________________________________________________________Run No. 1 2 3 4 5* 6 7 8 9__________________________________________________________________________Temperature, °C. 570 590 560 570 580 580 580 590 600Contact Time, Sec. 1.28 1.28 1.98 2.68 1.98 3.40 0.74 2.68 1.98Conversion, % 15.7 15.43 26.9 29.5 26.6 42.8 12.5 39 28Selectivity, %cis-stilbene 57.1 52.4 65.2 65.5 61.8 59.7 44.5 60 53.9trans-stilbeneBibenzyl 27.4 29.4 16.3 13.8 17 8.7 38.7 11 18.2Benzene 6.4 8.3 8.6 9.4 9.9 15.2 6.5 13.6 13.1CO.sub.2 2.1 3.6 3.4 3.7 3.6 6.9 3.7 5.9 6.6__________________________________________________________________________ *Average of 3 runs
EXAMPLE 4
An oxidant was prepared as in Example 2, above, and recalcined at 800° C. for 2 hours and then at 900° C. for 3 more hours. The Sb/Pb atomic ratio of this composition was 1:2. It was employed in the same reactor used in Examples 2 and 3 and the dehydrocoupling of toluene was carried out in the reactor as previously described in these examples using various steam-toluene ratios. Reaction temperature was 560° C. and contact time was about 4.23 seconds. Other conditions and results are presented in Table 4 below.
Table 4__________________________________________________________________________Run No. 1 2 3 4 5 6 7 8 9 10 11 12__________________________________________________________________________Steam/Toluene 2.0 2.0 2.0 2.0 0.48 0.48 0.48 0.48 0 0 0 0Reaction Time, min. 1 3 5 7 1 3 5 7 1 3 5 7Conversion, % 65.3 40.8 30.5 20.9 53.3 29.2 17.3 11.8 41.7 16.5 9.4 7.9Selectivity, % cis-stilbene 6.3 7.0 6.8 5.9 5.2 5 3.00 2.00 5 1.2 0.9 0.6 trans-stilbene 54.3 60.4 58.7 50.7 44.4 42.7 25.8 17.2 42.9 15.9 7.4 4.9 Bibenzyl 3.8 8.3 11.6 17.7 6.9 20.1 30.4 30.8 15.1 31.9 23.4 17.7 Benzene 21.6 13.8 13.6 15.4 22.1 15.4 20.4 25.9 18.7 21 30.3 34.5 CO.sub.2 3.5 2.0 2.0 3.9 9.0 7.6 12.8 16.9 8.9 22.9 32.8 37.5__________________________________________________________________________
EXAMPLE 5
Another series of runs were made wherein toluene as dehydrocoupled in the same apparatus and following the same procedure given in Examples 2-4. In these runs, a masterbatch of oxidant having an Sb/Pb atomic ratio of 1:2 was prepared in the manner described in Example 2 and samples of this masterbatch were then recalcined at various temperatures for various periods of time. The samples were then evaluated as oxidants in the dehydrocoupling of toluene in the same apparatus and using the same method used in Examples 2-4. Reaction temperature was 560° C., a contact time of 4.2 seconds was used, the ratio of steam to toluene of the feed was 2.0 and the reaction time was 3 minutes. Results obtained at the various calcination temperatures and times are presented in Table 5 below.
Table 5__________________________________________________________________________Run No. 1 2 3 4 5 6* 7 8 9 10__________________________________________________________________________Calcining Temp. °C. 600 700 800 800 900 900 900 1000 1000 1100Calcining Time, hr 2.0 3.0 2.0 4.0 1.0 3.0 5.0 2.0 4.0 3.0Surface area, m.sup.2 /g 0.37 0.32 0.25 0.26 0.28 0.22 0.22 0.21 0.15 0.26Conversion, % 80.2 79.4 62.9 63.2 57 51.2 45.7 24.1 16.3 15.7Selectivity, %cis-stilbene 40.2 37.9 52.6 53.5 58.6 65.9 68.5 49.2 35.8 31.8trans-stilbeneBibenzyl 1.9 1.8 3.5 3.3 4.7 4.1 6.7 29.5 36.4 43.5Benzene 34.9 38.1 24.9 24.8 19.7 15.6 12.8 8.5 12.7 8.8CO.sub.2 11.4 11.2 7 7 6.5 5.2 3.9 4.6 6.7 7.7__________________________________________________________________________ *Average of 3 runs
EXAMPLE 6
An oxidant was prepared by adding 58.3 g of Sb 2 O 3 , 134 g of PbO and 23.3 g of Bi 2 O 3 in sequence to 250 ml of water with stirring. The resulting slurry was heated with stirring to evaporate the water. The remaining solid was dried in an oven at 110° C. overnight and then calcined at 900° C. for two hours. The finished oxidant had an Sb/Pb/Bi atomic ratio of 1:1.5:0.25 and a surface area of 0.42 m 2 /g.
The oxidant prepared as described above was employed in a series of runs wherein toluene and steam in a mol ratio of 1:2 were contacted at various conditions with the oxidant contained in the reactor described in Example 2 and following the procedure described in that example. Reaction conditions and the results obtained are presented in Table 6 below.
Table 6______________________________________Run No. 1 2 3 4 5 6 7______________________________________Temperature, ° C. 560 560 580 580 580 580 580Contact Time, sec. 4.23 4.23 1.42 1.42 1.42 1.42 1.42Reaction Time, min. 1 3 1 3 5 7 0.17Conversion, % 74.5 53.2 47.3 23.2 14 9.7 42.6Selectivity, % cis-stilbene 6.6 7.7 7.6 6.3 4.6 3.5 5.5 trans-stilbene 56.5 65.9 62.2 51.8 37.5 29 44.6 Bibenzyl 3.2 6.7 11.4 30.2 47.5 55 22.6 Benzene 21.3 10.4 9.9 5.3 4.3 5.7 15.1 CO.sub.2 3.2 1.5 1.2 0.7 0.7 1.4 4.4______________________________________
EXAMPLE 7
A metal- and oxygen-containing composition prepared as in Example 5 and having the same Sb/Pb/Bi atomic ratio (1:1.5:0.25) was employed as a catalyst for dehydrocoupling toluene to stilbene. Following the same procedure as in the previous examples, oxygen was fed as air at a rate of 80 ml/min. over 18 ml (25g) of catalyst along with the steam and hydrocarbon (molar ratio 2:1) in the several runs carried out at 580° C. at a contact time of 0.85 second. Results obtained under these conditions over the several different reaction periods employed are presented in Table 7 below.
Table 7______________________________________Run No. 1 2 3______________________________________Reaction Time, min. 3 40 70Conversion, % 35.5 28 30Selectivity, % cis-stilbene 3.4 2.69 2.9 trans-stilbene 28.2 22 23.6 Bibenzyl 30.2 30.6 31.1 Benzene 17.4 19.4 18.1 CO.sub.2 15.7 20.4 18.6______________________________________
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Toluene and toluene derivatives are oxidatively dehydrocoupled to produce stilbene and stilbene derivatives by heating toluene or a toluene derivative in the vapor phase with a metal- and oxygen-containing composition which functions as an oxidant or oxygen carrier and has the empirical formula
Sb.sub.a Pb.sub.b Bi.sub.c O.sub.d
wherein a is 1, b is 0.2-10, c is 0-5 and d is a number taken to satisfy the average valences of the Sb, Pb and Bi in the oxidation states in which they exist in said composition. Alternatively, the same metal- and oxygen - containing composition can be employed as a catalyst for the dehydrocoupling reaction when oxygen or an oxygen-containing gas is heated with the hydrocarbon reactant.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic mending device for automatically restarting a loom after removing an improperly picked weft from the cloth fell and, more particularly, to an improper weft removing device capable of extracting an improperly picked weft from the cloth fell by winding up the improperly picked weft.
2. Description of the Prior Art
An automatic mending device is disclosed in Japanese Utility Model Publication No. 56-17503. This automatic mending device removes an improperly inserted weft from the cloth fell, and then places the same weft properly in the shed by means of a picking nozzle and suction means disposed on the picking side and the arriving side of the loom, respectively. Such a mending manner of the prior art automatic mending device is undesirable in view of the quality of the cloth, because the weft once picked up improperly and beaten into the fabric with the reed is woven in the cloth.
An invention disclosed in Unexamined Japanese Patent Publication No. 59-21757 extracts an improperly inserted weft by the suction of a suction nozzle or by the winding action of a waste removing roller after separating the improper weft from the cloth fell. However, according to the prior invention, the improperly inserted weft needs to be separated from the cloth fell prior to extraction and hence requires special separating means for separating the improper weft from the cloth fell.
SUMMARY OF THE INVENTION
Accordingly, it is a first object of the present invention to enable easy extraction of an improperly inserted weft from the cloth fell without using any special separating means such as employed by the prior art and to enable the elimination of the extracted weft in a form facilitating subsequent disposal of the eliminated improper weft.
According to the present invention, upon the occurence of a mispick, namely, when a weft stop signal is given by a weft stop motion controller, the rear end portion of the improper weft extending in the vicinity of a picking nozzle is moved into a winding unit by the action of a guide nozzle disposed near the picking nozzle, then the improperly inserted weft is then cut at a position in a portion thereof extending between the winding unit and the picking nozzle with a cutter, and then the winding unit winds the improperly inserted weft in a manner pulling the same away from the cloth fell to extract the weft from the shed.
The winding unit holds the rear end portion of the improperly inserted weft between a tubular rotary member and a winding member and winds up the weft on the winding member. Upon the completion of winding-up the weft, the winding member is separated from the rotary member to release the weft gathered in loops in order to facilitate subsequent disposal of the extracted weft. The winding member serves also as an ejecting nozzle. After being separated from the rotary member, the winding member blows air through a hole therein in order to eject the loops of the weft. The winding member is embodied in a rotary piston capable of axially sliding within a housing relative to the rotary member. Accordingly, the axial movement of the winding member relative to the rotary member is controlled by a dynamic fluid.
It is a particular feature of the present invention to position the winding unit away from normal picking path traveled by weft threads so that the improperly inserted weft is pulled in a direction away from the cloth fell as it is wound up by the winding unit. Accordingly, the improperly inserted weft is pulled gradually away from the cloth fell and hence the weft can be extracted easily by a comparatively small force. The pulling dirction is decided by the disposition of the winding unit or an auxiliary yarn guide. Naturally, the winding member and the rotary member are rotated with a sufficient torque to extract the improperly inserted weft, and the pulling speed of the winding member and the rotary member is optionally controlled in accordance with the strength of the weft to be extracted.
SUMMARY OF THE INVENTION
An arrangement according to the present invention for solving the problem of the conventional improperly inserted weft removing device has the following characteristics.
First, an improperly inserted weft is extracted by the positive winding motion of a winding unit and the weft is pulled away from the cloth fell and toward the shed as it is wound up. Accordingly, a special operation for separating the improperly inserted weft from the cloth fell is not necessary in removing the weft, and hence the weft removing device does not have any sophisticated mechanism for separating the improperly inserted weft from the cloth fell and the weft removing device is simplified accordingly.
Furthermore, according to the present invention, since an improperly inserted weft is wound up positively by a driving rotary member and a rotatable and axially movable winding member in a form facilitating the ejection of the extracted weft, the weft can be surely and smoothly wound up and ejected. Still further, since the improperly inserted weft is held between the rotary member and the winding member prior to the start of a winding operation, the weft is wound positively and is extracted by a sufficient force.
Incidentally, when the improperly inserted weft is not guided properly to the winding unit or when the improperly inserted weft is broken while being guided to the winding unit or while being extracted from the cloth fell, complete extraction of the improper weft is impossible.
Accordingly, it is a second object of the present invention to detect the condition of extraction of the improperly inserted weft electrically during the weft removing operation and to control the subsequent operation of the loom properly according to the results of the detection.
In order to achieve such an object, according to the present invention, the presence of an improperly inserted weft is detected at a predetermined position near the winding device at the start and after the completion of a weft winding-up operation, and the start or interruption of the improper weft removing operation or the restart of the loom is controlled according to the results of the detection. Particularly, the present invention detects the condition of the weft removing operation and the progress of the weft removing operation through the comparison of a time necessary for the extraction of the improper weft with a reference time.
Under the above-mentioned control mode, the presence of the weft is detected by a detector on the side of the winding unit during and after the completion of the weft extracting operation and appropriate measures are taken according to the existing condition of the weft extracting operation. Therefore, erroneous operation in that the loom is restarted when the weft is not fully extracted is prevented without failure. Accordingly, complete automatic mending function is ensured.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a weft removing device according to the present invention,
FIG. 2 is a longitudinal sectional side elevation of the improper weft removing device of FIG. 1,
FIG. 3 is a sectional view taken on line III-IV in FIG. 2,
FIG. 4 is an enlarged fragmentary sectional view showing a detector and and associated components from the device of FIG. 3,
FIG. 5 is an enlarged front elevation of the detector of FIG. 4,
FIG. 6 is a block diagram of a control unit of the device of FIG. 1,
FIG. 7 is a time chart showing the sequential operation of the components of the weft removing device of FIG. 1,
FIG. 8 is a front elevation of an alternative arrangement showing a different arrangement of a yarn guide,
FIG. 9 is a side elevation showing the yarn guide of FIG. 8,
FIGS. 10 and 11 are side elevations showing respective modifications of the yarn guide of FIG. 8,
FIG. 12 is a plan view of an alternative embodiment having a movable weft removing device provided on a loom,
FIG. 13 is a front elevation of the movable weft removing device of FIG. 12,
FIG. 14 is a side elevation showing another configuration of a movable weft removing device, and
FIG. 15 is a cross section of a guide sleeve in the embodiment of FIG. 14.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 to 3 illustrate the mechanical constitution of an improperly inserted weft removing device, 1, which comprises, as the principal units thereof, a guide nozzle 2, a cutter 3 and a winding unit 4.
The guide nozzle 2 is disposed between a picking nozzle 5 and the picking side of a fabric or cloth 6 and is directed in a direction deviating from the picking path, for example, obliquely upward. The cutter 3 is disposed adjacent to the head of the picking nozzle 5 and near a tubular yarn guide 7. In this embodiment, the cutter 3 and the yarn guide 7 are held fixedly by suitable supporting means.
The winding unit has a winding member 9 and a rotary member 10 which are supported rotatably within a tubular housing 8. The winding member 9 is supported for rotation and axial sliding movement with a rod 17 supported by a stroke bearing 18. A nozzle 12 is formed in the central portion of the free end of the winding member 9. A conical winding surface 13 is formed on the circumference of the free end of the winding member 9. The nozzle 12 communicates with a connector 16 attached to the housing 8 for introducing a fluid therethrough, by means of radial holes 14, an annular groove 15 formed in the circumference thereof and a hole formed through a sliding bearing 11. The winding member 9 and the rod 17 are formed coaxially and integrally in a single member. The rod 17 is supported axially slidably by the stroke bearing 18. The free end of the rod 17 is located opposite to a pressing member 22 fixed to the piston rod 21 of a power cylinder 20. The rod 17 is urged always rightward, as viewed in FIG. 2, by a coil spring 24 provided between a sleeve 19 serving also as a spring seat and a spring seat 23. The rightward movement of the winding member 9 is limited by a cap 25, while the leftward movement of the same is limited by the rotary member 10. The sleeve 19 is supported rotatably on a ball bearing 26 within the cap 25 attached to the free end of the housing 8.
A conical recess 28 having a conical surface complementary to the conical winding surface 13 is formed in the rotary member 10 opposite to the winding surface 13. The hollow rotary shaft 29 of the rotary member 10 is supported rotatably on ball bearings 30 within the housing 8. The ball bearings 30 are held in place by an end cap 31 attached to the open end of the housing 8. An ejecting passage 32 opening into a trash box 33 is formed through the rotary shaft 29. A gear 34b fixed to the output shaft of a driving motor 35 is meshed with a gear 34a attached to the rotary member 10 to drive the rotary member 10 rotatably at a predetermined speed.
The winding member 9 and the rotary member 10 are disposed opposite to each other with a suitable space therebetween within the housing 8. A guide tube 36 extends transversely to and is joined to the housing 8 at a position corresponding to the space between the winding member 9 and the rotary member 10. The upper and lower ends of the guide 36 are open. The interior of the guide tube 36 communicates with the space between the winding member 9 and the rotary member 10 by means of a guide hole 37 formed in the housing 8 at a position corresponding to a position below the middle of the guide tube 36. If necessary, a cover plate 38 may be attached to the upper open end of the guide tube 36. As illustrated in FIGS. 4 and 5, a detector 40 is disposed near the guide hole 37 and is held on a detector holding plate 39. The detector 40 comprises a light emitting element 41 and two light receiving elements 42. The light emitting element 41 and the light receiving elements 42 are directed toward the center of the guide hole 37 and the light receiving elements 42 are disposed symmetrically with respect to a center line passing the center of the guide hole 37 and the light emitting element 41.
Referring now to FIG. 6 showing the constitution of a control unit 43, the detector 40 is connected through an amplifying circuit 44 to one of the input terminals of a comparator 45. A reference setting device 55 is connected to the other input terminal of the comparator 45. The output terminal of the comparator 45 is connected directly to one of the input terminals of an AND gate 47 and through a NOT circuit 46 to one of the input terminals of an AND gate 48. A first timer 49 and a second timer 50 provide timer signals C and D of fixed times T1 and T2 upon the reception of a winding start signal A and a winding end signal B, respectively. The first and second timers 49 and 50 are connected to the other input terminals of the AND gates 48 and 47, respectively. The output terminals of the AND gates 47 and 48 are connected to the input terminals of an OR gate 51. The OR gate 51 is connected through a driver 52 to a relay 53. A contactor 54 of the relay 53 is incorporated into a circuit which generates a signal to inhibit the restart of the loom or a signal to interrupt the weft removing operation.
FIG. 7 shows a series of sequential actions of the weft removing device 1.
In the normal picking operation, the picking nozzle 5 pulls out wefts 56 from a measuring and storing device and picks the wefts 56 successively into sheds of warps 57.
Upon the occurrence of a mispick, a weft stop motion unit provides an H-level (Logic "1") signal, namely, a weft stop signal, to actuate a brake so that the loom is stopped automatically in the next weaving cycle. A mispick is detected by a well-known yarn sensor or the like positioned at the edge of the cloth on the arriving side where the picked weft 56 arrives.
Upon the reception of the weft stop signal, the measuring and storing device, not shown, releases the weft 56 so that the weft 56 of an appropriate length can be supplied to the picking nozzle 5. This appropriate length is such a length necessary for extending the weft 56 at least from the picking nozzle 5 to the guide hole 37 of the winding device 4. The free weft 56 of such an appropriate length can be obtained, when the measuring and storing device is of a drum type, by retracting the retaining pin to unwind, for example, one turn of the weft 56 on the drum or, when the measuring and storing device is of a roller-pneumatic type, by temporarily unclamping the weft 56 for a predetermined time.
When the weft stop signal is given to the loom the guide nozzle 2 blows air to blow the weft 56 extending between the picking nozzle 5 and the cloth 6 into the tubular yarn guide 7 of the winding device 4 to avoid the weft 56 extending from the edge of the cloth 6 being cut by the cutter 58.
At the same time, compressed air supplied from an external compressed air source is blown through the nozzle 12 of the winding member 9 into the ejecting passage 32 of the rotary member 10 to produce a negative pressure in the space between the winding member 9 and the rotary member 10 and its vicinity. Consequently, the weft 56 is sucked through the guide tube 36 and the guide hole 37 into the ejecting passage 32. While the weft 56 is being sucked into the guide tube 36, the cutter 3 performs a cutting operation. However, since the weft 56 is moved away from the cutter 58, the cutter 58 is unable to cut the weft 56 and hence the weft 56 and the improperly inserted weft 56a still remain continuous. While the weft 56 is thus being controlled for the improper weft extracting operation, the loom is stopped in the next picking cycle succeeding the improper picking cycle, and then the loom is reversed to open the warp shed as it was when the improperly inserted weft 56a was inserted. At this moment, the guide nozzle 2 stops blowing air while the winding member 9 continues blowing compressed air through the nozzle 12 for some time after the loom has been reversed.
While compressed air is still being blown through the nozzle 12, the power cylinder 20 is actuated to cause piston rod 21 to shift the rod 17 leftward, as viewed in FIGS. 1 and 2, against the resilient force of the coil spring 24. Consequently, the conical winding surface 13 of the winding member 9 is pressed against the conical recess 28 of the rotary member 10 to hold the weft 56 between the conical winding surface 13 and the conical recess 28. At the same time, the cutter 3 is actuated to cut the weft 56 extending between the picking nozzle 5 and the yarn guide 7 at a position near the picking nozzle 5.
Then, the driving motor 35 is actuated automatically to rotate the rotary member 10. Since the winding surface 13 and the surface of the conical recess 28 are joined frictionally, the winding member 9 is driven by the rotary member 10 at the same speed as the rotary member 10 to wind the weft on the winding surface 13, so that the improper weft 56a is extracted from the cloth fell 6a. Since the yarn guide 7 is offset toward the shed of the warps 57 from an extension of the cloth fell 6a, and hence the improper weft 56a is pulled in a direction obliquely deviating toward the shed of the warps 57 from the cloth fell 6a, the improper weft 56a is extracted under a small resistance and practically without interfering with the warps 57. The improper weft 56a can be pulled in such a direction by disposing the yarn guide 7 or the winding unit 4, more specifically the guide tube 36 of the winding unit 4 when the yarn guide 7 is not provided, at a position offset toward the shed from the cloth fell 6a.
Thus the winding member 9 and the rotary member 10 wind the improper weft 56a in loops on the winding surface 13. After the winding operation has continued for a fixed period of time, the driving motor 35 is stopped automatically. Prior to stopping the driving motor 35, the piston rod 21 of the power cylinder 20 is retracted to allow the coil spring 24 to separate the winding surface 13 from the conical recess 28. Simultaneously, compressed air is blown through the nozzle 12 to blow the loops of the improper weft 56a toward the conical recess 28. Consequently, the loops of the improper weft 56a are ejected through the ejecting passage 32 of the hollow rotary shaft 29 into the trash box 33. After the improper weft 56a has thus been removed, the loom is reversed further by a necessary phase angle, and then starts the normal weaving operation upon the reception of an automatic operation command.
During a series of the improper weft removing actions, the detector detects the entrance of the improper weft 56a into the guide hole 37 photoelectrically and provides a detection signal E. The detection signal E is applied to the input terminal of the comparator 45 after being amplified by the amplifying circuit 44. The comparator 45 compares the detection signal E with a predetermined reference value F and, when the result of the comparison indicates that the improperly inserted weft 56a is in the guide hole 37, provides a comparison signal G of H-level, which is given to the AND gate 48 after being inverted by the NOT ciurcuit.
On the other hand, upon the reception of a winding start signal A of H-level at an appropriate time, the first timer 49 provides a timer signal C of H-level for a predetermined time T1. The timer signal C is applied to the other imput terminal of the AND gate 48. While the timer signal C is on H-level, the AND gate 48 provides an output signal of H-level when the comparator 45 provides an output signal indicating that any improperly inserted weft is not in the guide hole 37, namely, a comparison signal G of L-level. The output signal of H-level of the AND gate 48 is given through the OR gate 51 to the driver 52 to actuate the driver 52. Consequently, the contactor 54 of the relay 53 is closed, and thereby the control unit of the loom provides a command to inhibit the restart of the loom or to interrupt the weft removing operation so that the winding operation is interrupted. Such a control operation is executed when the yarn guide malfunctions or the improperly inserted weft is broken accidentally during the weft removing operation.
Upon the completion of the weft winding operation, a winding end signal B is given to the second timer 50. Then, the second timer 50 provides a timer signal D of H-level for a predetermined time T2. If the comparator 45 provides the comparison signal G of H-level indicating the existence of the yarn while the timer signal D is on H-level, the contactor 54 of the relay 53 is closed, through the same process as mentioned above, to provide the restart inhibition command or the improper weft removing operation interruption command. Such a control operation is executed when the winding operation is performed improperly or the yarn is broken.
The winding start signal A and the winding end signal B are provided, for example, at a moment when the driving motor 35 is started and at a moment when the same is stopped, respectively.
In this embodiment, the detector 40 is disposed at an optimum position near the guide hole 37 within the guide tube 36, however, the detector 40 may be disposed at another position, for example, at a position near the yarn guide 7. In this embodiment, the detector 40 comprises one light emitting element 41 and two light receiving elements 42, however, the detector 40 may comprise a plurality of light emitting elements 41 and a plurality of light receiving elements 42.
FIGS. 8 and 9 show a second embodiment of the present invention, in which a yarn guide 7 similar to that of the first embodiment is shifted in extracting an improperly inserted weft 56a. The yarn guide 7 is held on the reed frame 59 of a reed 58 so that the lower opening thereof faces the triangular region (see FIG. 9) formed by the reeds 58 and the shed 60 of the warps 57. Upon the occurence of a mispick, the reed frame 59 is stopped at a position where the yarn guide 7 is located between a guide nozzle 2 and a guide tube 36. Accordingly, a weft 56 is guided through the yarn guide 7 to the guide tube 36.
Since the reed frame 59 is moved for one cycle of bearing motion by reversing the loom after a mispick has occurred, the yarn guide 7 pulls the weft from the cloth fell 6a toward the shed 60 of the warps 57 as the reed 58 is moved away from the cloth fell 6a. Thus, the improperly inserted weft 56a, particularly, a portion of the weft 56a on the picking side of the cloth, is separated from the cloth fell 6a. Since the yarn guide 7 is located so that the weft 56a is pulled, in a direction obliquely deviating toward the shed 60 of the warps 57, from the extension of the cloth fell 6a without interfering with the warps 57, the weft 56 which was partly separated from the cloth fell 6a during the reverse operation of the loom is extracted by being pulled away from the cloth fell 6a toward the shed 60 by a small force.
In the second embodiment shown in FIG. 8, a housing 8 serves also as a cylinder while a winding member 9 serves also as a piston. A working fluid is supplied through an inlet formed in an end cap 61 into the housing 8 to bring the winding member 9 into contact with a rotary member 10 against the resistance of a coil spring 63.
In the second embodiment, the tubular yarn guide 7 is held on the reed frame 59, however, the yarn guide 7 may be held on another member which is reciprocated similarly to the reed frame 59.
Furthermore, the yarn guide 7 need not necessarily be formed in a tubular shape so long as the yarn guide is able to guide the weft 56 properly. Therefore, the yarn guide 7 may be formed in the shape of a hook and may be fixed to the reed frame 59 as illustrated in FIG. 10, or the yarn guide 7 may be replaced with an electromagnetic yarn guide 64 having a movable rod 65 which as shown in FIG. 11, guides the weft 56 extending between the movable rod 65 and the air guide 66 of the reed 58.
In the second embodiment, since the improperly inserted weft 56a is separated positively from the cloth fell 6a, the weft 56a can be extracted by a small force under a small resistance of the warps 57. Furthermore, since the direction of extraction of the weft 56a is dependent on the position of the yarn guide 7, the winding unit 4 may be disposed at an optional position.
FIGS. 12 and 13 show a third embodiment of the present invention in which a housing is movable while a guide tube 36 is stationary.
In the third embodiment, a winding unit 4 is supported by a bracket 67 on two horizontal guide rods 69 extending between a pair of frames 68 so as to be movable along the guide rods 69 in a direction parallel to the cloth fell 6a. The bracket 67 is connected to the piston rod 71 of a power cylinder 70 mounted on one of the frames 68. Thus, the bracket 67, the frames 68, the guide rods 69 and the power cylinder 70 constitute a winding unit shifting means. A guide tube 36 is held fixedly on the frame 68 near the edge of the cloth so as to be disposed opposite to the guide hole 37. The guide tube 36 extends perpendicular with respect to the housing 8 and has upper and lower open ends. A guide hole 72 is formed in the guide tube 36 at the middle thereof so as to be opposite to the guide hole 37 of the housing 8 when the winding unit 4 is moved to the operating position. When the winding unit 4 is moved to the operating position, a weft guided by the guide tube 36 is able to enter the space between a rotary member 10 and a winding member 9 through the guide holes 72 and 37. In this embodiment, the yarn guide 7 is a hook fixed to the free end of a picking nozzle 5 together with a guide nozzle 2.
Prior to guiding a weft 56 to the winding unit 4, the piston rod 71 of the power cylinder 70 is projected to move the winding unit 4 from the resting position to the operating position, where the guide hole 37 formed in the housing 8 is located opposite to the guide hole 72 of the guide tube 36 so that a weft is able to be sucked from the guide tube 36 into the housing 8 through the guide holes 72 and 37. Then, air is blown through a nozzle 12 formed in the winding member 9 to produce an air current from the guide tube 36 through the guide holes 72 and 37 into an ejecting passage formed in the rotary member 10. Consequently, the weft 56 guided into the guide tube 36 is caused to enter the ejecting passage 32 through the guide holes 72 and 37, together with the air current.
In the third embodiment, the winding unit 4 is linearly movable, while in a fourth embodiment shown in FIGS. 14 and 15, a winding unit 4 is supported by a bracket 73 on a supporting shaft 74 so as to be turnable. The bracket 73 is turned on the supporting shaft 74 by a power cylinder 75. In the fourth embodiment, a guide hole 37 formed in a housing 8 is always located opposite to a guide hole 72 formed in a guide tube 36 and hence a weft 56 can be surely sucked into the housing 8. The fourth embodiment is provided with a transfer bar 76 for positively transferring the weft 56 from the interior of a guide tube 36 to a guide hole 37 formed in the housing 8 of the winding unit 4. The transfer bar 76 is attached together with a rotary actuator 77 to the side wall of the guide tube 36. The transfer bar 76 is moved through a slit 78 formed in the guide tube 36 into the guide tube 36 to transfer the weft 56 from the interior of the guide tube 36 to the guide hole 37.
In the third and fourth embodiment, the winding unit 4 is moved near to the guide tube 36. However, it is also possible to move the guide 36 near to the winding unit 4 or to move both the winding unit 4 and the guide tube 36 toward each other.
In the third and fourth embodiments, the weft 56 is blown into the guide tube 36 with the guide nozzle 2, then the guide hole 72 of the guide tube 36 and the guide hole 37 of the winding unit 4 are positioned opposite to each other, and then the weft 56 is sucked positively from the guide tube 36 into the interior of the winding unit 4 by the agency of an air current. Therefore, reliable operation for winding the weft 56 and the improper weft 56a is achieved. Furthermore, the provision of the transfer bar 76 on the guide tube 36 further ensures the transfer of the weft 56 from the guide tube 36 to the interior of the guide hole 37 even when the air current for sucking the weft 56 into the guide hole 37 is unstable.
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An improperly inserted weft removing device for a shuttleless loom which weaves a fabric by picking a weft measured and stored on a measuring and storing device into a shed of warps by the agency of a jet of a fluid jetted through a picking nozzle, said weft removing device including a winding unit for extracting an improperly inserted weft from the cloth fell of the cloth being woven on the shuttleless loom upon the occurence of a mispick; a guide nozzle for deflecting the weft from the picking path and guiding the same to a predetermined position in the winding unit, which is disposed between the picking nozzle and the edge of the cloth on the picking side; a cutter for cutting the weft extending between the picking nozzle and the winding unit; and a controller for controlling the winding unit, the guide nozzle and the cutter for a series of sequential weft removing actions.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/233,662, filed Sep. 19, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to fishing jig lures. More specifically, the invention is a new device and an improved method for making a metallic lipped plastic fish lure with at least one hook rigged by a hand held device. A metal lip jig is disclosed for attaching various baits.
[0004] 2. Description of Related Art
[0005] The related art of interest is a crowded art, but none discloses the present invention. There is a need for a hand device for a fisherman which can rig a plastic lure with a metal lip and at least one hook while on location. Additionally, as a subcombination, a metal lip jig, per se, for attaching bait is disclosed.
[0006] The related art will be discussed in the order of perceived relevance to the present invention.
[0007] U.S. Pat. No. 5,157,859 issued on Oct. 27, 1992, to Clarence L. Wirkus describes a cast lead fishing jig comprising an upturned hook portion with a long shank imbedded in an oval shaped body of cast lead having a convex upper surface and a concave lower surface. The eye portion of the hook is bent at a right angle to protrude up from the body proximate its nose. A worm, leech or a plastic wriggler can be attached to the upturned hook portion. The jig is distinguishable for requiring an environmentally dangerous lead body made by casting around a bent hook.
[0008] U.S. Pat. No. 6,041,540 issued on Mar. 28, 2000, to Carl J. Potts describes an artificial soft plastic fishing lure comprising three threaded fish strung on one line to simulate a school of bait fish. A fish has artificial eyes, a V-shaped dorsal fin, a dorsal rattle or fish-attracting scent in an elongated dorsal void space, and a ventral Y-shaped fiber weed guard. The artificial fishing lure is distinguishable for its requirement for various adornments.
[0009] W.I.P.O. patent application Ser. No. WO/97/09875 published on Mar. 20, 1997, for Allen R. McDonald et al. describes a lead sinker coated with either rubber, plastic or latex and impregnated with fish oils. The lead sinker is distinguishable for being directed to only the lead sinker.
[0010] The following remaining references are all directed to the threading of a worm on a hook by various devices. The patents are distinguishable for being limited to worms or fish without metal lips.
[0011] U.S. Pat. No. 4,674,220 issued on Jun. 23, 1987, to Ronald H. Bearce, Jr. et al. describes a pocketable worm threading device comprising a cylindrical barrel member containing an extendable hollow brass needle and a clipped cap. A live worm is threaded on the extended needle. A hook on a leader line is placed at the tip of the extended needle and the worm is threaded onto the leader line. The cap is used to remove a hook from a fish and to aid in tying a hook to a line. The device is distinguishable for being limited to threading worms onto a leader line and hook.
[0012] U.S. Pat. No. 4,706,403 issued on Nov. 17, 1987, to John L. Reynolds describes a fishing bait threader tool having a bored handle with three slots to accommodate a hollow needle at one end and a solid needle with a radial arm having a crook portion, a return portion and a forward extending prong. The tool is distinguishable for its two needle and handle structures.
[0013] U.S. Pat. No. 4,118,881 issued on Oct. 8, 1978, to Douglas A. McFarlane describes a method and apparatus for threading worms on fishhooks comprising a rectangular block with various grooves and a hole for inserting part of the worm, threading the worm with a tubing in a groove, and placing the worm upright on the block. A hook is placed on the tip of the tubing and threaded with the worm. The device is distinguishable for its structural differences.
[0014] U.S. Pat. No. 4,848,019 issued on Jul. 18, 1989, to Paul Toogood describes an automatic worm threader comprising an upright hand gripping member with a right-angled extending member and another upright worm impaler having a concave end for accommodating the hook. The device is distinguishable for its unique structure.
[0015] U.S. Pat. No. 5,125,180 issued on Jun. 30, 1992, to Gordon G. Dean describes a fishhook worm baiting tool comprising an elongated L-shaped solid rod with a blind bore for attaching the hook and a wingnut at the opposite end for securing the leader line in a taut manner for threading the worm onto the line and hook. The device is distinguishable for its different structure.
[0016] U.S. Pat. No. 4,915,631 issued on Apr. 10, 1990, to Oscar T. Robinson et al. describes a fishing worm threader device comprising a handle with a projecting fishing line support with a slit and a hollow tube for threading the worm. The device is distinguishable for its structure.
[0017] U.S. Pat. No. 5,155,930 issued on Oct. 20, 1992, to Faustino Monarez describes a worm threading device comprising a hollow handle for storing a live worm and having an arm member at a right angle with a notch for holding the leader line while threading the worm onto the hook placed in the tip of the hollow shank on the handle. The device is distinguishable for its arm member and the storage capacity in the handle.
[0018] U.S. Pat. No. 5,367,814 issued on Nov. 29, 1994, to Steven H. Petersen describes an apparatus for baiting a fishing line with a worm comprising a cylindrical rod having a throughbore and a tube extending to a sharp edge for threading a live worm. A fishing line is threaded from the reel through the tube, the impaled worm and the handle to be wound around the handle. The line is unwound from the device and tied to a hook after the impaled worm is detached from the apparatus. The apparatus and method of baiting are distinguishable for the requirement of threading the line through the tube and alongside the tube for impaling the worm and removing most of the line.
[0019] U.S. Pat. No. 5,735,071 issued on Apr. 7, 1998, to David J. Gouldie et al. describes a fishing accessory for threading a worm on a hook and sharpening the hook barb comprising a pen-like assembly with the main body being hollow and storing the piercing assembly having a threaded base. The cap has a sharpening stone and a pocket clip. The worm is threaded with the hook and line in the usual manner. The fishing accessory is distinguishable for its storage handle structure.
[0020] None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
[0021] The present invention is directed to a new device and an improved method of manually making a metal lipped plastic fish lure with at least one hook on a leader line rigged by a novel hand held device. The hand tool has a telescopic antenna element with an open end and located next to a rod element with a right angle bend for holding the metal lip which can have a hook attached to it. A wooden handle is hollowed out for insertion of a sharp pointed spike based in a cork. The distal end of the handle can have a throughbore for insertion of a cord loop. The method of making a hooked and metal lipped lure comprises piercing a plastic lure, e.g., a minnow, with the spike. The prepared leader line has at least one hook on its end or two hooks in tandem. The pierced plastic minnow is placed on the telescopic antenna element with a small portion of the end exposed for insertion of the barbed tip of at least one hook. The opposite end of the leader line has the metal lip conventionally provided with a punched out holder strap and optionally a hook. The fisherman places the metal lip by its holder strap on the extending right angled rod. It is preferred that the length of leader line from the first hook to the second hook is taut by extending the telescopic antenna. Then the process of moving the plastic lure up the leader line to the metal lip is performed. The rigged lure can now be released from the tool by collapsing the telescopic rod. A subcombination is a metal lip jig lure, per se, on which either soft plastic bait, frozen cut bait, live bait can be hooked or dressed further with feathers, fur or animal hair.
[0022] Accordingly, it is a principal object of the invention to provide a hand tool that can form a fish lure by adding at least one hook and a metal lip attached to a leader and threading a plastic fish lure.
[0023] It is another object of the invention to provide a method of producing a flexible plastic lure with a metal lip and hooks by utilizing a novel hand tool.
[0024] It is a further object of the invention to provide a combination hand tool with a telescopic antenna for holding a lure and a terminal hook, and a separate metal lip holder.
[0025] Still another object of the invention is to provide a combination tool having a spike in its handle for piercing a plastic lure in preparation for making the hooked and metal lipped lure.
[0026] Yet another object of the invention is to provide a subcombination of a metal lip jig lure, per se, on which either soft plastic bait, frozen cut bait, live bait can be hooked or dressed further with feathers, fur or animal hair.
[0027] It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
[0028] 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
[0029] [0029]FIG. 1A is an environmental, perspective view of a metal lip jig rig threader tool according to the present invention with the telescoping rod in an extended position being used to thread bait on a metal lip jig rig.
[0030] [0030]FIG. 1B is a perspective view of the metal lip jig rig threader tool according to the present invention with the telescoping rod in a retracted position.
[0031] [0031]FIG. 2 is side elevation view of a plastic minnow threaded with two hooks by the jig rigging tool of the present invention.
[0032] [0032]FIG. 3 is an enlarged perspective view of a metal lip jig rig according to the present invention.
[0033] [0033]FIG. 4 shows and elevation view of a lure having the metal lip jig rig of the present invention and a single hook.
[0034] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] In one aspect, shown in FIGS. 1A and 1B, the present invention is directed to a hand tool 10 for rigging a plastic fish lure 12 with a metal lip jig 14 and at least one hook 16 . The tool 10 comprises a telescopic antenna-like hollow rod 18 attached to a hollow wooden handle 20 . The tool 10 has a spike 22 (in dashed lines) with a sharp point 24 which is stored in a bore 29 defined in hollow handle 20 when not in use, a cork plug 26 being used to retain the spike 22 in the handle 20 . The cork plug 26 can be frictionally seated at the end 28 of the handle 20 . The spike 22 may be removed from the handle 20 and mounted in the hollow end of the telescoping rod 18 , as shown in FIG. 1B, for forming a longitudinal throughbore 30 in the plastic minnow lure 12 . The handle 20 also has another throughbore 34 proximate the distal end 28 extending transversely through the handle 20 , through which a loop of cord 36 is attached. The cord loop 36 can be hung from a fisherman's belt.
[0036] The leader line 38 has been pre-rigged with a terminal hook 16 and attacked to a metal lip jig 14 . A second hook 40 is attached to the pre-fashioned metal lip jig 14 by a rivet 32 and spurs 33 and has a punched out strap 44 . A right-angled rod 46 positioned adjacent the telescopic rod 18 has a rubber collar 48 for conveniently abutting the metal lip 14 or for wrapping line in a slot in the rubber collar 48 .
[0037] A first outer brass tubing 41 having a closed end 42 fits axially in the hollow wooden handle 20 and extends out from the end of the handle 20 opposite the cork 26 . A second inner brass tubing 43 fits slidingly inside the first outer tubing 41 with a wire 45 extending from its bottom end which rests on the closed end 42 of the first outer tubing 41 when the inner tubing 43 is in a retracted position, so that the top end of the tubing does not slide down into the outer tubing 41 , but remains at least one inch above the end of the outer tubing 41 . When the spike 22 is inserted in the open end 49 of inner tubing 43 , a plug 51 , e.g. a glue plug, approximately an inch from the open end 49 prevents the spike 22 from going further into the second tubing 43 , leaving about two inches of the spike 22 extending from the open end 49 of inner tubing 43 .
[0038] In FIG. 2, the completed lure 50 is depicted with the hooks 16 and 40 separated by a hidden leader line 38 formed by the following process.
[0039] The process of forming the rigged lure 50 begins with removing the spike 22 from the handle 20 and inserting the spike 22 into the open end 49 of inner tubing 43 , the telescoping rod 18 being in a retracted position, as shown in FIG. 1B. A lure or item of bait, such as a plastic minnow 12 , is inserted longitudinally over the telescoping rod 18 , tail end 52 first, the pointed end 24 of the spike 22 piercing the minnow and defining a longitudinal bore 30 in the minnow 12 . The minnow 12 is threaded down over the telescoping rod 18 , and the spike 22 is removed from the rod 18 , leaving a small length of the inner tubing 43 exposed. The barb of the terminal hook 16 is now placed in the open end 49 of the telescopic rod 18 . The metal lip jig rig 14 is attached to the right-angled rod 46 by its punched out strap 44 . The telescoping rod 18 is moved to the extended position shown in FIG. 1A to stretch the leader line 38 tight. The plastic lure 12 is now pushed up over hook 16 and down the leader line 38 . The head of the minnow 12 is attached to the second hook 40 by sliding the lure over the neck 58 of the metal lip jig rig 14 and piercing the minnow 12 with the barb of second hook 40 , and the base of the tail is attached to the first hook 16 to form the finished product, i.e., the rigged lure 50 . The telescoping rod 18 is retracted, hook 16 is removed from inner tubing 43 , and metal lip jig 14 is removed from rod 46 . This rigging procedure can be performed with the inventive tool by the fisherman while fishing. Thus, an efficient and quick method of rigging a plastic lure with a metal lip and hooks has been shown.
[0040] The advantages of this method of rigging a plastic lure with a metal lip are that the weighted lure can be cast, trolled or jigged on the bottom. The hooks are arranged with the barbs up to minimize any snagging problems. Any plastic lure can be used, such as fish, crayfish, worms, shrimp, frogs, lizards, hellgrammites, tube tails, grubs, and the like. Even lipped bucktail lures can be made. Spinners can be attached at the rivet or the metal lip end. The metal lips can be colored. Live and frozen bait such as salmon eggs, crayfish, hellgrammites, leeches, night crawlers, and nymphs can be incorporated to make these jig lures. Fur, feathers and animal hair can be added as dressing for use with a fly or spinner rod.
[0041] One outstanding advantage of this tool 10 is the addition of bait lure to the fish lure 12 by adding a liquid bait lure composition to either the spike 22 or the end of the telescopic rod 18 before moving the lure onto the leader line 38 .
[0042] In FIG. 3, a metal lipped jig 56 according to the present i invention is shown enlarged having a bulbous metal lip portion 14 , such as a metal lip made from brass coated with nickel, with one strap 44 , which is punched out of the lip or otherwise attached to the lip 14 , for attachment to the fishing line, as well as attachment to rod 46 of tool 10 . An elongated neck portion 58 has a rivet 32 and spurs 33 for fastening second hook 40 securely to the lip portion 14 . A terminal eyelet 60 is conveniently provided on the neck portion 58 for attachment of another trailing hook, if desired, or for tying leader line 38 to metal lip jig 14 . Bait such as soft plastic lures, frozen bait, and live bait can be hooked to form a lure approximately 4 inches long. The jig 56 can be approximately 1¼ inches long, {fraction (9/16)} inch wide lip 14 , and ⅛ inch thick. The metal lip portion 14 can be conveniently bent at various angles to control the depth of the lure. Advantageously, the metal lip jig rig 14 eliminates the necessity of using lead weights or sinkers.
[0043] The versatility of a single metal lip jig rig device is evident when one rig device can be readily converted into numerous other lures by adding any one of bait lures such as soft plastic, frozen, live, cut, and tied on flies and streamers. The lures can also be used with various fishing rods such as spinning, fly and bait rods. A foot long trailer line having a hook can be attached to the terminal hook 16 for adding salmon eggs, a fly, etc. because the metal lip acts as a sinker without requiring lead weights.
[0044] It should be especially noted that the present invention is an ergonomic and environmentally safe alternative to the use of lead jigs being used.
[0045] It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.
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A metal lip jig threader device for rigging a flexible plastic bait, frozen bait, cut fresh bait, and live bait having a metal lip with one hook on a leader line in one fluid step. Additional dressing such as feathers, fur or hair can be added to the lure. An improved method is shown for making a metallic lipped live or artificial fish lure with at least one hook. An improved metal lip jig is shown having a hook secured by a rivet and spurs.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods and/or apparatus for increasing the overturning resistance of retaining walls and has been devised particularly though not solely for use with crib walls.
2. Brief Summary of the Invention
It is an object of the present invention to provide a method of and/or apparatus for increasing the resistance to overturning of retaining walls.
Accordingly in one aspect the invention consists in a method of increasing the resistance to overturning of a retaining wall including the steps of applying to the retaining wall intermediate of its height a plurality of discrete interlinking members, attaching a first interlinking member to the retaining wall intermediate of the height thereof and a last interlinking member to a deadman.
In a further aspect the invention consists in interlinking restraining means for increasing the resistance to overturning of a retaining wall, said interlinking restraining means including a plurality of interconnected, interlinking members one end of the plurality of members being attached to a retaining wall intermediate of its height and the other end being attached to a deadman.
In a still further aspect the invention is in a method of increasing the resistance to overturning of a retaining wall, including the steps of applying to the retaining wall intermediate of its height a plurality of discrete interlinking members, attaching a first one of the interlinking members to the retaining wall intermediate of the height thereof and to a last one of interlinking members, a deadman.
To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and it is not our intention to limit the scope of the invention by those disclosures and descriptions, or otherwise, than by the terms of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
One preferred form of the invention will now be described with reference to the accompanying drawings:
FIG. 1 is a diagrammatic cross section of part of a retaining wall in the form of a crib block wall having an overturning resisting means according to the invention associated therewith,
FIG. 2 is a schematic view of a crib wall header block having hook means and showing the reinforcing therein,
FIG. 3 is schematic side elevational view of a discrete interlinking means,
FIG. 4 is a schematic side elevational view of the last in a series of interlinking means,
FIG. 5 is a schematic plan view of deadmen connected to the resisting means, and
FIG. 6 is a schematic view showing the arrangement of reinforcing in the block of FIG. 2.
DETAILED DESCRIPTION
Referring to the drawings an overturning resisting means for assisting in resisting the overturning of a retaining wall, in particular a crib wall, will now be described.
The crib wall 1 in FIG. 1 is made of stretchers, headers and false headers in the known way up to the height of a hooked block 2 and of headers and stretchers thereabove. The hooked block 2 is shown more particularly in FIG. 2 and has reinforcing therein comprising longitudinal tendons 3 arranged to reinforce a hook 4 by parts of the reinforcing being extended as at 5. Transverse reinforcing is provided at 6 and preferably at 7, though the reinforcing at 7 may not be necessary. The block has a depression 8 in which stretchers 9 are placed and similar stretchers 10 are placed at the rear of the lower portion of the crib wall. To provide resistance or add to resistance to overturning discrete interlinking means in the form of hooked block members 15 are provided, such blocks having hooks 16 at each end and a longitudinal intermediate portion 17.
In FIG. 4 there is shown a terminal tension member 20 having a T member 21 at one end of the longitudinal member 22 and a hook 23 at the opposite end.
The blocks 15 are positioned as shown in FIG. 1, alternately upright and lying on the side, thus the first block 25 is shown on its side the next block 26 upright, and so on and thus the blocks positions are alternated at 25 and 26 as shown. Finally a terminal block 20 is positioned vertically. Stretcher blocks 30 are positioned one above the other as may be seen in FIGS. 1 and 5 against the T head 21 of the terminal block 20 to form deadmen i.e. beams substantially parallel to the crib wall 1.
Reinforcing is provided in the hooked members 15 and member 20 and such reinforcing may be provided in what might be described as formed shape 40 as in FIG. 3 or alternatively welded rods 41,42 and 43 may be interconnected as shown in FIG. 4. The blocks of FIG. 2 may be formed into a rectangular arrangement supported by stirrup members 50, the stirrup members having plastic ends 51 as desired to position the members against the forms.
The blocks of FIG. 2 may be produced in molds which have removable pieces so that the slightly complicated form can be satisfactorily removed. In particular a removable member may be fitted in space 55 and the walls of that space may be sloped slightly to provide draw enabling withdrawal of the removable mold piece. Of course other alternatives are possible.
It can be seen from the foregoing that a tension means is provided which will resist overturning of the crib wall 1 and thus add strength against overturning in a simple yet economical way. In particular where the crib wall is to be erected against a relatively solid earth bank i.e. one which has not been disturbed, considerable excavation savings can be provided since the only alternative is to provide a double crib wall in lower areas of the bank to be retained, which requires a large amount of unnecessary digging and has a further disadvantage of disturbing soil which otherwise need not be disturbed.
It is to be noted that the tension restraining means is arranged in a horizontal plane and this is advantageous again since it reduces the amount of digging necessary to place the tensioning means in position.
The stretchers 30 acting as deadmen do not need further restraint since they will be firmly fixed in position preferably against undisturbed soil and any twisting will be restrained by earth resistance and therefore likley to be immaterial.
The ends 52 of the links 15 also bear against soil and add to the overturning resistance.
The invention may also be used to increase the resistance to overturning of retaining walls other than crib walls, e.g. Modular panel walls or cast in situ walls. In such cases slots either T shaped or rectangular are provided in the walls at intervals and Tee or bulbous headed blocks similar to the blocks so mounted therein by placing the head of block in the cross bar of a Tee shaped hole then moving the block into the stem of the hole or by passing the head of the block 20 through a rectangular hole and rotating it through 90° to take up a locked disposition.
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A plurality of interlinking restraining members are interconnected to each other and the ends connected respectively to a deadman and to a retaining wall, e.g. a crib wall, to increase the resistance to overturning of the wall. The interlinking members are generally C shaped and formed of reinforced concrete.
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FIELD OF THE INVENTION
The present invention relates to a Ziegler-Natta type catalyst, a process for preparing such a catalyst and its use in polyolefin production.
BACKGROUND TO THE INVENTION
It is known that anhydrous magnesium dichloride derivatives which are suitable for the preparation of Ziegler-Natta catalysts can be obtained by reacting an organo magnesium or a Grignard reagent with a halogenated compound. For example, U.S. Pat. No. 4,186,107, and its equivalent FR-A-2464965, each describe the synthesis of a catalyst composed of a titanium halide deposited on a magnesium halide support. The support may be prepared by reacting a dialkyl magnesium with an alkyl aluminium halide in a hydrocarbon solvent. The support may be treated with an electron donor such as a dialkyl ether in order to provide a means for controlling its morphology. Very low temperatures are preferred in the synthesis of the catalyst and all the examples were conducted at around −65° C. This presents a serious disadvantage in the industrial applicability of this method.
EP-A-98196 reports the synthesis of magnesium dichloride catalyst supports having spherical particles of controllable size distribution by reacting a dialkyl magnesium with an alkyl chloride in the presence of an electron donor, preferably an ether.
EP-A-68200 describes a process for the production of granular ethylene polymers having a large, uniform particle size and a high bulk density. An organic magnesium compound is reacted with a hydropolysiloxane or a silicon compound to give a silicon-containing reaction product which is then reacted with the reaction product of an organic aluminium chloride compound with a mixture of alcohols. The product of this reaction is further reacted with a halogen-containing titanium or vanadium compound. This approach is further developed in U.S. Pat. No. 4,223,118 which also requires the use of the reaction product of an organic magnesium compound with a hydropolysiloxane or silicon compound. This silicon-containing reaction product is further reacted with an aluminium alkoxide which optionally contains a halogen atom. These processes suffer from a disadvantage that complex synthetic procedures are required to achieve the desired catalyst.
EP-A-093454 reports a solid catalyst component for alpha-olefin polymerisation made by reacting a magnesium compound such as n-butyl, sec-butyl-magnesium with a catalyst such as obtained by reacting aluminium chloride with ethyl benzoate. No steps are taken to control the morphology or particle size distribution of the solid catalyst component.
U.S. Pat. No. 4,873,300 reports a catalyst preparation by reacting with a reducing halide source a mixture of a hydrocarbon soluble magnesium alkyl compound, an aliphatic alcohol and a titanium compound.
SUMMARY OF THE INVENTION
The present invention provides a process for preparing a Ziegler-Natta catalyst, which process comprises:
(i) mixing in a hydrocarbon solvent a dialkyl magnesium compound of general formula MgR 1 R 2 with a chlorinating agent soluble in the hydrocarbon solvent under conditions to precipitate controlledly a magnesium dichloride derivative, wherein R 1 and R 2 are each independently a C 1 to C 10 alkyl group preferably a C 2 to C 8 alkyl group, and the chlorinating agent is obtainable from the reaction between an alcohol of general formula R 3 OH and an alkyl aluminium chloride of general formula R 4 n AlCl 3−n , in which R 3 OH is a cyclic or branched C 3 to C 20 alcohol, each R 4 is independently a C 2 to C 8 alkyl and n is 1 or 2; and
(ii) titanating the magnesium dichloride derivative with a chlorinated titanium compound to produce the Ziegler-Natta catalyst.
The catalyst obtainable by this process produces polyolefins, especially polyethylene homopolymers or copolymers, with a low amount of fines of less than 125 μm, no agglomerates of greater than 1600 μm, a narrow particle size distribution, a high bulk density and a regular shape. Moreover, the catalyst has high activity and high sensitivity versus hydrogen.
The dialkyl magnesium compound is preferably n-butyl sec-butyl magnesium or butyl ethyl magnesium although other dialkyl magnesium compounds such as butyl octyl magnesium, dibutyl magnesium and dihexyl magnesium can be used. The dialkyl magnesium derivative should be soluble in the hydrocarbon solvent used in the process.
The chlorinating agent obtainable from the reaction between the alcohol and the alkyl aluminium chloride may have the general structure (R 3 O) n AlCl 3−n , preferably (R 3 O) 2 AlCl. The alcohol is selected such that, after reaction with the alkyl aluminium chloride, the chlorinating agent product is a compound soluble in the hydrocarbon solvent used in the process. This is important for particle size and particle size distribution control. The alcohol may be 2-ethyl-1-hexanol, 2-methyl-1-pentanol, 2-ethyl-1-butanol, 2-methyl-2-propanol, 2-methyl-1-propanol, cyclopentanol or cyclohexanol, preferably 2-ethyl-1-hexanol. The preferred alkyl aluminium chloride is diethyl aluminium chloride.
The molar ratio of the alcohol to the alkyl aluminium chloride is usually from 0.5 to 2.5, preferably about 2. The molar ratio of the alkyl aluminium chloride to the dialkyl magnesium compound is usually in the range of from 0.8 to 2.2.
Other methods of making compounds of the formula (R 3 O) n AlCl 3−n include reacting together an alkoxy aluminium derivative Al(OR 3 ) 3 , such as aluminium ethoxide or isopropoxide, with a chlorinating agent, typically an acyl halide such as acetyl chloride.
Any non-aromatic hydrocarbon solvent may be used in the process although, from a practical viewpoint, it is usual for the solvent to be removed subsequently. Hydrocarbon solvents of less than 6 carbon atoms tend to boil too easily whereas hydrocarbon solvents having more than 7 carbon atoms are often difficult to remove. Accordingly, preferred hydrocarbon solvents are hexane or heptane.
In step (ii) any chlorinated titanium compound suitable for titanating the magnesium dichloride derivative may be used. Such chlorinated titanium compounds include TiCl 4 , TiCl 3 OR 5 , TiCl 2 OR 5 2 , TiClOR 5 3 , or mixtures thereof, in which each R 5 is independently a C 2 to C 8 alkyl, preferably TiCl 4 .
A dialkyl ether may be added into the process to improve the fluff bulk density achieved during polyolefin synthesis. Preferably, the dialkyl magnesium compound is premixed in the hydrocarbon solvent with an acyclic dialkyl ether of general formula R 5 —O—R 6 , in which R 5 and R 6 are each independently C 2 to C 10 alkyl groups. Preferably, the dialkyl ether is diisoamyl ether. The molar ratio of the dialkyl magnesium compound to the dialkyl ether is preferably 1.93. The ether is used to increase the polyolefin fluff bulk density but has little or no influence on the catalyst granulometry or particle size distribution.
Turning to the general procedure for preparing the Ziegler-Natta catalyst, the dialkyl magnesium compound may be dissolved in the hydrocarbon solvent and mixed with the dialkyl ether at room temperature to form a solution. The alcohol may be added to the alkyl aluminium chloride which is dissolved in the hydrocarbon solvent to form a solution. This solution may be left at room temperature for a period of at least 0.5 hours so as to ensure that a reaction takes place between the alcohol and the alkyl aluminium chloride to form the chlorinating agent. Alternatively, the dialkyl magnesium compound and the chlorinating agent may be added to the solvent at the same time. However normal, the reaction mixture can be stored under an inert atmosphere for of the order of 4 to 6 days without degradation.
The solution of the chlorinating agent, usually in the hydrocarbon solvent, is mixed rapidly with a solution of the dialkyl magnesium compound in the hydrocarbon solvent, for example by dropwise addition, so as to achieve mixing with controlled precipitation. Under these conditions, the “MgCl 2 ” precipitation proceeds very slowly and a good control of the particle size and the particle size distribution is achieved. A catalyst of poor morphology is obtained if the mixing is performed without appropriate control, for example where a solution of the dialkyl magnesium compound is added to excess chlorinating agent (i.e. in the reverse order).
The magnesium dichloride derivative is preferably aged without agitation, usually at ambient temperature in the range 20° to the boiling point of the hydrocarbon solvent preferably about 85° C., generally for a period in the range 1 hr to 1 week, prior to titanation step (ii). Aging generally requires further heating of the magnesium dichloride derivative in suspension so as to produce a catalyst with improved morphology.
Preferably, the magnesium dichloride derivative precipitated from step (i) is washed with the hydrocarbon solvent to remove reaction by-products prior to titanation step (ii). Usually, the magnesium dichloride derivative is washed several times with the hydrocarbon solvent. This helps prevent TiCl 3 precipitation during the titanation step, which would otherwise result in a catalyst with poor morphology.
The titanation agent may be added dropwise, usually at room temperature to the magnesium dichloride derivative to produce the catalyst. Usually, the reaction proceeds first at room temperature then at 50° C. and finally at 98° C. The catalyst may then be washed 4 times at 60° C. with the hydrocarbon solvent. The catalyst may be used in olefin polymerisation, such as ethylene polymerisation or copolymerisation, in the form of a slurry or after drying.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in further detail by way of example only, with reference to the following Examples.
EXAMPLES
Catalyst Synthesis
1. Raw Materials
All manipulations are conducted under nitrogen atmosphere. n-butyl sec-butyl magnesium (DBM) (1M in heptane) and TiCl4 are purchased from Aldrich and used as received. Diethyl aluminium chloride (DEAC) (25 wt % solution in heptane and butyl ethyl magnesium (BEM) (15 wt % in heptane) are purchased from Akzo. The alcohols are purchased from Aldrich and dried over molecular sieve (3A°). Diisoamyl ether (DIAE) is purchased from Aldrich, dried and distilled over sodium/benzophenone. Heptane and hexane are dried and distilled over sodium/benzophenone.
2. Chlorinating Agent General Preparation Procedure
DEAC (0.05 mole) is weighed into a 500 ml round bottom flask and diluted with 50 ml heptane, in a nitrogen box. The flask is then equipped with a thermometer, a magnetic stirrer, a 100 ml pressure-equalized dropping funnel and a gas inlet. The system is taken out of the nitrogen box and connected to a nitrogen inlet system.
An alcohol (0.1 mole dissolved in 40 ml heptane) is transferred to the dropping funnel and added dropwise at room temperature (22-25° C.) to the DEAC/heptane solution (addition time: 10′). The reaction is exothermic (T° goes up to 55° C.) and the formation of fumes is observed. The mixture is left over night: at room temperature without agitation. For convenience, the solution is usually left for the night at room temperature. However, no differences were observed for shorter (2 hours) or longer (2-4 days) reaction times. This method was used with the following alcohols: cyclopentanol, 2-ethyl-1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-propanol, and 2-methyl-1-propanol. In each case, a clear solution is obtained.
The method was repeated using the aromatic or linear alcohols phenol, benzyl alcohol, ethanol, and octanol. In each case, a white solid derivative is produced which is insoluble in the reaction solvent. This indicates a lack of suitability for those alcohols in the production of a hydrocarbon soluble chlorinating agent.
3. Catalyst Preparation
In the following examples, a chlorinating agent prepared as described above with 2-ethyl-1-hexanol as the alcohol is used in the production of a catalyst based on n-butyl sec-butyl magnesium (DEM) or butyl ethyl magnesium (BEM).
Catalyst A
DBM (0.027 mole) is weighed into a 4-neck, 1 L round bottom flask and diluted with 90 ml of heptane in the nitrogen box. The flask is then equipped with a mechanical stirrer, a 100 ml pressure-equalized dropping funnel, a thermometer and a condenser. The flask is taken out of the dry box and connected to a nitrogen inlet system. The solution is stirred at room temperature at a rate of 200 rpm.
Diisoamyl ether (DiAE) (0.014 mole, diluted with 10 ml heptane) is transferred to the 100 ml dropping funnel on the 1 L flask and added dropwise (in about 5′) at room temperature to the DBM/heptane mixture. The dropping funnel is rinsed with 20 ml of heptane and the stirring is continued for 15′. No apparent change is observed.
The DEAC/2-ethyl-1-hexanol chlorinating agent mixture is added dropwise at 22-25° C., via the dropping funnel, to the DBM/DIAE/heptane solution. Precipitation (white solid) begins after addition of about 35-40 ml (total volume 140 ml). Total addition takes about 1 hr. The dropping funnel is rinsed with 50 ml of heptane. Agitation is continued for 1 hr at room temperature then for 2 hrs at 98° C. (oil bath T°: 110° C.). The temperature of the oil bath is decreased to 85° C. (T° in the flask: 75° C.). The agitation is stopped. The settling of the solid is very fast (less than 5′); however the supernatant remains cloudy. The temperature is held at 85° C. for the night (about 15 hrs).
The supernatant is decanted via a cannula and the “MgCl2” is washed with 250 ml portions of heptane, 4 times at 50° C. After washings, the white “MgCl2” is slurried in about 250 ml of heptane.
TiCl4 (0.06 mole in 90 ml heptane) is added dropwise (in 45′, T°=24° C., goes up to 28° C.). The mixture becomes slightly yellow. Stirring is continued for 1 hr at room temperature then for 5 hrs at 50° C. and finally for 2 hrs at 98° C. Agitation and heating are stopped for the night.
Washings are performed at 50° C. with hexane (4×250 ml). The settling is fast (<5′) The final catalyst is pale brown and used as slurry for the polymerisations.
A catalyst sample is dried (filtration on a P3 coarse filter then vacuum drying at 50° C.) and a fine tan powder (no agglomerates) is obtained.
Catalyst B
This catalyst was prepared in exactly the same manner as catalyst A except that BEM was used instead of DBM. The chlorinating agent mixture is added dropwise at 25° C. to the BEM/DIAE/heptane solution and precipitation begins after addition of about 20 ml (15 mins). The TiCl4 is added dropwise in 50 mins.
COMPARATIVE EXAMPLES
Catalyst C1 (using DEAC as chlorinating agent)
DBM (0.5 mole) is weighed into a 4-neck, 1 L round bottom flask and diluted with 50 ml of heptane in the nitrogen box. The flask is then equipped with a mechanical stirrer, a 100 ml pressure-equalized dropping funnel, a thermometer and a condenser. The solution is stirred at room temperature at a rate of 310 rpm.
DEAC (0.1 mole, diluted with 90 ml of heptane) is added dropwise at room temperature to the DBM/heptane mixture. During the addition, a white MgCl2 precipitate is formed. The solid appears to be colloidal and does not settle, even after an extended period of time (5 hrs).
The suspension is further heated for 2 hours at 90° C., under agitation. Heating does not improve the MgCl2 settling.
The temperature is decreased to room temperature and TiCl4 (0.05 mole, in 90 ml heptane) is added dropwise over 45′. The slurry turns grey-black. Stirring is continued for 1 hr at room temperature then for 1 hr at 50° C.
Washings are performed at 50° C. with hexane (4×250 ml). The settling is improved and takes only 20′. The final catalyst is dark grey and used as slurry for the polymerizations.
This example shows that DEAC alone is not suitable for chlorinating agent for the production of catalysts with a controlled narrow particle size distribution (see table 2: PSD Broadness: 30.3 compared to 19.4 for the catalyst of the invention A). The C1 catalyst produces polymer fluff with a high level of fines below 125μ (see table 4: 12.3 wt % compared to 0.4 wt % for the invention catalyst) and a lot of aggregates above 1600 μm (see table 4: 4 wt % compared to 0 wt % for the catalyst of the invention).
Catalyst C2 (no DIAE addition)
This catalyst is prepared in exactly the same manner as invention catalyst A except that no DIAE is used.
This example shows that DIAE:
increases the fluff bulk density (from 0.15 g/cc to 0.26 g/cc; see table 3)
has no influence on the fines content in the polymer fluff (see table 4: 0.2 wt % below 125 μm compared to 0.4 wt % for the catalyst A).
has little influence on the catalyst particle size distribution (see table 2: PSD Broadness: 24.1 for C2 compared to 19.4 for the catalyst of the invention A).
Catalyst C3 (reverse addition)
This catalyst is prepared in exactly the same manner as the catalyst of the invention A except that a reverse addition process is used: DBM is added dropwise to the DEAC/2-ethyl-1-hexanol mixture; no DIAE is added.
This example shows that this process is not suitable for the production of a catalyst with a narrow particle size distribution (see table 2: PSD Broadness: 25.5 compared to 19.4 for the catalyst of the invention A).
The fluff produced with the C3 catalyst contains a high amount of fines below 125 μm (see table 4: 8.4 wt % compared to 0.4 wt % for invention catalyst A) and a lot of agglomerates (see table 4: 6.5 wt % compared to 0 wt % for the catalyst of the invention A).
Catalyst C4 (no aging process)
This catalyst is prepared in exactly the same manner as invention catalyst A except that the aging procedure is omitted.
After the addition of the DEAC/2-ethyl-1-hexanol chlorinating agent to the DBM/DIAE mixture, the agitation is continued for 1 hr at room temperature then for 2 hrs at 98° C. The agitation is stopped, the supernatant is decanted and the “MgCl2” is washed as described for catalyst A.
This example shows that the aging process is needed for the production of a catalyst with a narrow particle size distribution (see table 2: PSD Broadness: 37.6 for C4 catalyst (without aging process) compared to 19.4 for the catalyst of the invention A).
The C4 catalyst produces PE fluff with a lot of fines below 125 μm(see table 4: 17.1 wt % compared to 0.4 wt % for the invention catalyst A) and a high level of agglomerates above 1600 μm(see table 4: 10.4 wt % compared to 0 wt % for the catalyst of the invention A).
4. Results
(a) Catalyst Synthesis
TABLE
Elemental analysis of dried catalysts
CATALYST
Ti
Mg
Cl
Al
TYPE
wt %
wt %
wt %
wt %
Catalyst A (DBM)
11.0
10.5
52.5
2.8
Catalyst B (BEM)
4.3
15.3
59.3
1.7
C1 (Comparative expl)
19.9
8.0
49.6
4.8
C2 (Comparative expl)
15.3
7.9
49.3
4.2
C3 (Comparative expl)
11.1
7.7
52.5
2.2
C4 (Comparative expl)
9.9
13.0
52.3
2.2
Catalyst Particle Size Distribution
The catalyst particle size distributions (PSD) are shown on Table 2. The catalyst average particle sizes are listed below and compared with the catalysts of the Comparative Examples.
TABLE 2
Catalyst Particle Size Distribution
Catalyst
d10
d50
d90
PSD
Type
(μm)
(μm)
(μm)
Broadness (*)
Catalyst A (invention)
22.8
43.4
64.8
19.4
Catalyst B (invention)
12.3
25.8
38.2
20.1
C1 (Comparative expl)
3.2
9.7
17.9
30.3
C2 (Comparative expl)
20.5
38.4
66.8
24.1
C3 (Comparative expl)
3.7
8.4
18.6
35.5
C4 (Comparative expl)
2.2
9.8
20.6
37.6
(*) Broadness = 20 (d90-d10)/d50
50: defined as the particle size at which 50% of the weight of the total catalyst in consideraton is less than
# that size.
As can be seen, the d 50 values of the catalysts of the invention are generally larger than the catalysts of the Comparative Examples. Catalyst B has a much larger d 50 than catalyst A. The catalysts of the present invention having a narrower PSD than those of the Comparative Examples.
(b) Polymerisation Results
The polymerisations are performed in a 4 liter stainless steel reactor fitted with a stirrer operating at a speed of 500 rpm (revolutions per minute).
The reactor is first loaded with 1.5 liters of purified iC4. The temperature is then increased to 90° C. and 4.7 Nl of hydrogen is introduced into the reactor.
The catalyst (20 mg) and the cocatalyst (TIBAL; 10 wt % solution in hexane; 80 ppm versus iC4) are introduced into the reactor by means of 0.5 1 of iC4.
The polymerisation is carried out for 1 hour, while continuously feeding ethylene to maintain the total pressure at 20.7 bars.
The results are shown in Table 3
TABLE 3
Catalyst
Productivity
MI5
Bulk Density
Type
(gPE/gcat.h)
(g/10′)
(g/cc)
Catalyst A (invention)
19000
7.2
0.26
Catalyst B (invention)
16100
9.9
0.32
C1 (Comparative expl)
8250
0.1
0.11
C2 (Comparative expl)
6050
0.6
0.15
C3 (Comparative expl)
11850
8.5
0.24
C4 (Comparative expl)
11100
11.0
0.27
Table 3 compares the activities for the different catalytic systems, using slurry catalysts in the production of polyethylene.
As can be seen from this Table, the activity for catalyst A (DBM) is higher than that for catalyst B (BEM). Catalysts C1 to C4 all have lower activity
Fluffs Particle Size Distribution
Table 4 shows the fluffs particle size distributions for the catalysts A, B and C1 to C4.
Both catalysts A and B produce fluffs with zero fines at <63 μm and peak size distribution at 500 μm of 87.6-87.8%.
TABLE 4
Fluff particle size distribution
Catalyst
Fluff Granulometry μm
Type
<63
63
125
250
500
1000
1600
2000
Catalyst A
0.0
0.4
2.0
9.2
87.8
0.6
0.0
0.0
Catalyst B
0.0
0.2
0.6
9.2
87.6
2.2
0.2
0.0
C1 (comp.
0.9
11.4
28.9
34.9
15.4
3.4
1.1
4.0
expl)
C2 (comp.
0.0
0.2
4.4
24.7
47.2
10.6
7.2
5.7
expl)
C3 (comp.
0.5
7.9
51.8
25.1
6.7
0.9
0.5
6.5
expl)
C4 (comp.
2.4
14.7
38.1
27.5
3.7
1.8
1.4
10.4
expl)
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A process for preparing a Ziegler-Natta catalyst, which process comprises:
(i) mixing in a hydrocarbon solvent a dialkyl magnesium compound of general formula MgR 1 R 2 with a chlorinating agent soluble in the hydrocarbon solvent under conditions to precipitate controlledly a magnesium dichloride derivative, wherein R 1 and R 2 are each independently a C 1 to C 10 alkyl group, and the chlorinating agent is obtainable from the reaction between an alcohol of general formula R 3 OH and an alkyl aluminum chloride of general formula R 4 n AlCl 3−n , in which R 3 OH is a cyclic or branched C 3 to C 20 alcohol, each R 4 is independently a C 2 to C 8 alkyl and n is 1 or 2;
(ii) removing unwanted reducing species by washing or reaction; and
(iii) titanating the magnesium dichloride derivative with a chlorinated titanium compound to produce the Ziegler-Natta catalyst.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to board games using a board and illuminated game pieces. The particular aspects of this invention relate to the illumination of the game pieces.
[0002] The game pieces of this invention employ design aspects, including shape, color, and material, to suit their role according to the game rules. Game pieces employ design aspects to facilitate visual recognition and differentiation to designate the respective players or “sides” participating in the game through a varying visual display within the game pieces.
[0003] Game pieces whose design aspects are not crucial to play of the game are free to have these design aspects presented in any manner Expression of these design aspects draws interest to the game, and can be custom made to enhance the value of a game board and the game pieces played thereon. This provides added economic value and selling price to a game over and above a game with conventional game pieces and/or board.
[0004] Various methods for illumination of game boards and game pieces exist in the prior art but none utilize the features of this invention which facilitate a changing visual image and coloration of game pieces. U.S. Pat. No. 3,579,856 discloses a game board whose game pieces are illuminated when placed over the ends of light transmitting fibers strategically placed across the underside of a game board. U.S. Pat. No. 3,854,725 discloses game pieces having incandescent lights therein that are selectively illuminated by inserting the game piece into electrical connections under each square of a chess board. U.S. Pat. No. 3,888,491 discloses a chessboard where , instead of game pieces moving across the board, each of the 64 regulation squares on the game board has a flush, transparent surface with a display tube thereunder whose appearance can be changed to represent one of the six figures used in chess; pawn, rook, knight, bishop, king and queen. U.S. Pat. No. 3,984,109 describes translucent chess pieces, each piece containing its own battery and light wherein the light in the piece is selectively actuated by remote control to indicate when the time to play that piece is close at hand. Published U.S. Patent Application 2009/0184468 dated Jul. 23, 2009 discloses egg-shaped game pieces with an internal LED which is energized by electromagnetic induction.
SUMMARY OF THE INVENTION
[0005] All of the above approaches to illuminating game pieces are largely monochromatic and emit a steady light. By contrast, the present invention discloses game pieces that can emit a colored light unique to each participant and wherein the emitted light is vibrant and can be varied in intensity.
[0006] Briefly, the aforementioned objects of the present invention are satisfied by providing game pieces illuminated by gas sealed within the game pieces which is excited to a plasma state.
[0007] A further object is the generation of this illumination through inductive coupling to a high-voltage radio-frequency source.
[0008] Another object provides for the game pieces to be constructed of clear or translucent material having the quality to contain and hold captive gas or mixture of gases to be excited electrically to a plasma state.
[0009] A further object is the freedom of motion and placement of the game pieces, which movement is typically accompanied by a change in color and intensity of the excited plasma within the game piece.
[0010] A further object of the invention is provision of means for exciting the plasma within the game piece.
DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a cross-sectional view of a game piece prior to gas filling and final processing;
[0012] FIG. 2 is a cross-sectional view of a game piece that has been filled with gas and is ready for use on the game board;
[0013] FIG. 3 is an example of a system used to fill game pieces with gas and seal them;
[0014] FIG. 4 is a schematic of the circuit used to excite the gas in the game pieces;
[0015] FIG. 5 is a cross sectional view of a game board and game pieces wherein the electrical components used for gas excitation within the game pieces are mounted inside a box-like structure with a game board integrated into the upper surface of that structure;
[0016] FIG. 6 is a cross sectional view of a game board and game pieces wherein the electrical components are mounted in a self contained box-like structure unattached to the game board but located in proximity to the game board and game pieces so as to illuminate the game pieces;
[0017] FIG. 7 is a perspective view of a chess board and chess pieces as an example of how the illuminated game pieces of the invention can be freely moved anywhere on a game board.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The illuminating glow of excited gas (plasma) contained within the game pieces 1 of this invention provides a fascinating and striking visual effect. The visual qualities of plasma produced by excitation of gases, or mixtures of gases, vary greatly. The shape of the game pieces, the gases used within the pieces and the means used to excite the gases within the pieces contribute to this visual effect.
[0019] The material used in the construction of the game pieces 1 of this invention impacts the production and durability of the game pieces. Glass is the most effective material for this invention given its clear or translucent properties, its inert properties, its rigidity, and its properties as an impervious container of gas.
[0020] The process for forming the game pieces 1 can be generalized as four steps. The first step is to form the general shape of the game piece 1 , leaving a disposable tube 2 attached to the game piece as shown in FIG. 1 . The second step in forming the game pieces 1 is to evacuate the air from within the game piece 1 by a vacuum pump 5 through the attached disposable tube 2 as shown in FIG. 3 . The third step is to fill the game piece with a pure gas or mixture of gases from pressurized containers 3 a and/or 3 b (See FIG. 3 ). The fourth step in producing the game pieces of this invention is to seal the gas within the game pieces by sealing the juncture of tube 2 and game piece 1 . This step will result in the separation of the game piece 1 from the tube 2 used for evacuation and filling This tube 2 may be discarded, leaving a sealed outer envelope 6 of game piece 1 ( FIG. 2 ).
[0021] The shape of the envelope 6 of game piece 1 can be any that is appropriate to the game for which the pieces are created such as pawn, rook, etc. used in classic chess. However, a unique aspect of this invention is that the shape of the game pieces' envelope 6 and the gas therein can be selectively mated to create highly attractive combinations that enhance the game playing experiences of the game in which the game piece is used.
[0022] This invention has infinite application in any number of board games. The game of chess with game pieces used in that game is illustrated in the Figures. However, any number of board games would benefit from use of the game pieces of this invention, for example, checkers, backgammon or any other board game. The game piece 1 can be formed in any shape to complement the rules of each board game in which it is used.
[0023] In addition to the infinite variations in/of shape and color, the excitation of the gas within the piece can be changed/modulated to give the appearance of movement within the piece as described in more detail below. This is particularly effective in low light where the pieces seem to take on an animated appearance as they are moved across the board.
[0024] The preferred gases used to fill the game pieces are neon, argon and krypton. Other gases that produce a visible aura when excited can also be used, for example, a mixture of carbon dioxide and air. Neon by itself generally emits a red aura; argon a gray blue color and krypton a gray/steel green color. When neon is mixed with argon it can emit a blue/red effect that borders on a light purplish color. By varying proportions of these gases, an infinite variety of colors emitted from the game pieces is possible. In a preferred embodiment of the invention the area within envelope 6 of game pieces 1 for each player is filled with the same gas but which is different from the other player. Thus, for example, in chess one player's game pieces would be filled with neon to emit a red glow and the other player's pieces filled with argon to emit a gray/blue color.
[0025] The gases will not actually mix as such, but rather the smaller molecules, usually neon, will migrate to the smaller areas of the game piece envelope 6 , while larger molecules, for example argon and krypton, will spread out and monopolize the larger, open areas of the envelope. This will create multicolored displays. By designing pieces with a combination of thoughtfully created open, and more contained areas, the display can be visually enhanced.
[0026] The design aspects of the game piece itself are implemented with the foremost intent to satisfy the rules of the game. Secondary design aspects of the game piece provide for aesthetics in the considerations put towards manipulating the intricacies of plasma. Other secondary design aspects may be thoughtfully constructed or incidental.
[0027] For purposes of this invention, the second step, evacuation, is necessary for two reasons. The first reason being the elimination of atmosphere from within the game piece to facilitate a complete exchange of ambient air for selected gas or gases. The second reason is the need to regulate the pressure within the final sealed game piece envelope to maximize the generation of plasma discharge within the piece.
[0028] Variation in the third, gas filling, step leads to a variety of visual effects. Gases will emit unique colors of light and mixtures of gases will create multicolored illuminations. These variations in color are intended to be used as features of the game piece when differentiation by color is crucial, preferred, or arbitrary. The pressure or partial pressures of the contained gases will affect the efficiency of illumination due to subtle interactions among the gaseous molecules.
[0029] To excite the gases within game piece 1 , just about any circuit providing high frequency and high voltage for promotion of plasma from unexcited gas can be used. The circuitry shown in FIG. 4 uses an AC to DC wall adapter to provide a low-voltage direct current. Direct current is oscillated by oscillator 7 into radio-frequency alternating current at low-voltage. Low-voltage radio-frequency alternating current is directed through a transformer 8 with the output being the radio-frequency alternating current at high-voltage. The output, an electromagnetic field, can be directed via antenna 9 to the proximity of the game board.
[0030] Differences in electrical circuitry, as well as antenna characteristics, will affect the efficiency of illumination. This invention relates to illuminated game pieces and any electrical circuitry capable of exciting a gas or mixture of gases contained within the sealed envelope of game piece 1 to a plasma state will be considered acceptable.
[0031] The illumination produced is related directly to the proximity of the game piece to the high-voltage radio-frequency antenna 9 . But, unlike the prior art noted above, there is no direct electrical connection between game piece 1 and an electrical source. Thus, the game pieces are in no way physically connected to any source of illumination and are thus free to be moved at will.
[0032] Additional flexibility of the claimed concept arises from the ability to use a single platform 10 surrounding the electrical circuitry and antenna 9 for multiple games as illustrated in FIG. 6 . In this Figure a game board 12 , for example a chess board, is merely placed on top of the upper surface of platform 10 to facilitate the playing of a game of chess. If the interest of the chess players wanes, a different game board 12 , e.g., checkers, can be substituted for the chess game board and play can continue with illuminated game pieces, the same or different from those used in the chess game. Thus a single platform 10 with electronic components can be used for multiple games. Alternately a game board 14 can be integrated into the top surface of the platform 10 as shown in FIG. 5 . In the latter embodiment the platform 10 is necessarily dedicated to that game.
[0033] The placements of the game pieces 1 on and near the platform 10 creates inductive coupling that precludes the necessity for exact placement of the game piece to obtain illumination. For example, as shown in FIG. 7 a game piece 10 is shown illuminated in a standard placement on the game board, considering the rules of the game, within the outlined area defined as an individual spot for a game piece involved in game play. The piece 17 is shown illuminated on the game board but not specifically within an area defined as an individual spot for a piece involved in game play. Thus, game pieces remain illuminated as long as they are in general area of the game board and need not be exactly within a square or other physical location on a game board to stay illuminated as is the case with the prior art discussed above.
[0034] The electrical components and antenna do not have a designated preferred configuration. This invention provides that the game pieces will be illuminated by inductive coupling to the high-voltage radio-frequency source. This only requires general proximity of the game pieces to the antenna 9 . Any combination of the game piece, game board and antenna that produces an illuminated game piece will be considered acceptable.
[0035] An object of this invention is the high visibility of the plasma generating field to the field of game play providing the illumination of game pieces in play. The light cast by the game pieces, especially in a dark surrounding, can provide a mystical aura to a game. When a player touches the envelope 6 of game piece 1 , that player acts as a ground which intensifies the electromagnetic field within the game piece, thereby increasing the intensity of light therein. Distance of game piece 1 from antenna 9 also changes the light intensity within game pieces 1 . Thus, the mere act of picking up a game piece 1 and moving it across the game board creates an infinite number of unique visual patterns, or glow, from the envelope of game piece 1 .
[0036] The invention described herein provides for variation to all components of the illuminated game pieces on a game board. Variations to the character of the game pieces will be easily achieved by those skilled in the art. Variations to the circuitry integral to producing a plasma state will be easily modified by those skilled in the art. Variation in the choice of board game played and the configuration of all components required by this invention to produce illuminated game pieces will be easily adjusted by those skilled in the art to suit their choice of game and their aesthetic desires. Accordingly, all such variations are provided for within the scope and spirit of the invention as defined by the claim.
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A board game whose game pieces contain a gas or mixture of gases. The gas inside the game pieces is electrically excited to illuminate the game piece. This illumination is achieved by inductive coupling the game piece to a high-voltage radio-frequency source located in or in the vicinity of the game board.
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FIELD OF THE INVENTION
[0001] Aspects of the disclosure relate to cash handling in a cash-centric environment. More specifically, aspects of the invention relate to real-time access to information regarding cash flows.
BACKGROUND
[0002] Cash flow refers to the movement of cash over a particular time period within a business or enterprise. The calculation of cash flow may be used as one measure to gauge financial health of the business. Managers in charge of cash flow management may use various tools to assist in making decisions involving cash flow.
[0003] A starting point for proper cash flow management involves use of cash flow projections. Accurate cash flow projections enable business mangers to make proper decisions regarding day-to-day operations and long-term strategic decisions such as investment decisions.
[0004] Good cash flow projections involve using up-to-date accurate data regarding inflows and outflows of cash over a period of time. These projections which may be in the form of cash flow statements involve estimation of operating cash flow. However, timely up-to-date data concerning operating cash flow is difficult to obtain in large retail operations. In large retail operations, accurate cash flow data may not be known until business close, as an accounting of each cash register's drawer has to be completed and reported to a corporate back office.
[0005] For example, a multi-store grocery chain may have multiple cashiers at each store handling numerous customers during a business day. When each store closes or at the end of the cashier's shift, each of the cashiers may have to tally in their cash register so that a final tally may be determined each store closing. At certain time of day the result may be forwarded to a central office which may be used to calculate cash flow for the grocery chain.
[0006] At particular scheduled times which may range from daily to once every few days or longer, an armored car or other means of transportation may be arranged such that cash receipts from the day or some other period of time may be picked up and transferred to a financial center or branch for deposit. Upon delivery to the financial center, cash may be deposited and may be made available for use by the business in another one to four business days.
[0007] Therefore, a need exists for a method, apparatus, and system for calculating and allowing use of cash flows for a business or enterprise in real-time. The calculation of real-time cash flows may enable mangers with cash management responsibilities to make informal business decisions regarding use of cash during the same business day for the entire enterprise.
SUMMARY
[0008] The following presents a simplified summary in order to provide a basic understanding of some aspects of the invention. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to the description below.
[0009] In one aspect of the invention, an end-to-end currency, handling and servicing apparatus is provided to any cash-centric business or enterprise. In various embodiments, the method, apparatus, and system may provide cash register till set up and balancing, back office reconciliation, and other cash payment handling activities.
[0010] In an aspect of the invention, a cash recycling apparatus is utilized to receive currency deposits and recycle the deposited currency for withdrawals. In an embodiment, the cash recycling apparatus may scan each deposit for counterfeits bills.
[0011] In another aspect of the invention, a currency recycling apparatus may be placed in each of a business customer's stores or locations. The currency recycling machines may be networked. In an embodiment, after each cashier shift or at other designated times, contents of a cashier's register till or drawer may be deposited into a currency recycling apparatus. In another embodiment, at shift start the currency recycling apparatus may withdraw a determined amount of cash in various denominations so as to stock a cashier's cash register till or drawer.
[0012] Furthermore, in an aspect of the invention contents and data from each of the networked currency recycling machines may be analyzed to determine real-time cash positions. In an embodiment, the real-time cash positions may be used to make projections and/or decisions regarding short and long term business decisions.
[0013] In yet another aspect of the invention, each of the currency recycling machines may be connected to a financial institution's network or infrastructure. In an embodiment, each deposit or withdrawal via the currency recycling machine may be credited or debited real-time to a customer's account. In another embodiment, real-time crediting and debiting of a customer's account may allow the customer to have immediate access to the customer's recent deposits and current balance for use in future transactions or for planning and forecasting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements.
[0015] FIG. 1 illustrates an example of a suitable operating environment in which various aspects of the disclosure may be implemented.
[0016] FIG. 2 illustrates a simplified diagram of a currency recycler in accordance with an aspect of the invention.
[0017] FIG. 3 illustrates various features of a currency recycler that may be used in accordance with aspects of the invention.
[0018] FIG. 4 illustrates additional features of a currency recycler used in various aspects of the invention.
[0019] FIG. 5 illustrates an interface screen that may be utilized to access information regarding the current cash position of the enterprise in accordance with an aspect of the invention.
[0020] FIG. 6 illustrates a withdrawal screen that may be used in accordance with an aspect of the invention.
[0021] FIG. 7 illustrates a user interface screen in accordance with an aspect of the invention.
[0022] FIG. 8 illustrates another user interface screen that may be used in accordance with an aspect of the invention.
[0023] FIG. 9 illustrates a report that may be generated and used in accordance with an aspect of the invention.
[0024] FIG. 10 illustrates a cash balance interface screen that may be used in accordance with an aspect of the invention.
[0025] FIG. 11 illustrates a report that may be generated in accordance with an aspect of the invention.
[0026] FIG. 12 illustrates a system configuration that may be used in accordance with an aspect of the invention.
[0027] FIG. 13 illustrates a method of providing immediate availability to amount deposited in accordance with an aspect of the invention.
DETAILED DESCRIPTION
[0028] In accordance with various aspects of the disclosure, systems and methods are illustrated for providing currency handling services and management. A financial institution such as a bank may provide immediate access and use of funds recently deposited using the currency handling apparatus, system, and method described below in various aspects of the invention. For illustrative purposes the financial instrument discussed throughout the below description is cash. However, as those skilled in the art will realize, the described aspects of the invention are not limited to just cash (paper money and coins) and but may also include other forms of liquid assets such as checks, bank notes, and money orders.
[0029] FIG. 1 illustrates an example of a suitable operating environment in which various aspects of the disclosure may be implemented. Currency or cash recyclers 102 , 104 , 106 may be located at various locations such as locations 101 , 103 , and 105 . The locations may represent different stores of a business enterprise. For example, locations 101 , 103 , and 105 may represent three different grocery stores located in different geographical areas belonging to a grocery chain. Those skilled in the art will realize that additional cash recyclers may be located in same stores or in other stores belonging to the grocery chain. In addition, those skilled in the art will realize that a grocery chain is only one illustrative example of the types of locations that cash recyclers may be located. For example, cash recyclers may also be located in gas stations, post offices, department stores, and other places where cash and other financial instruments are deposited or withdrawn.
[0030] FIG. 1 further illustrates that cash recyclers 102 , 104 , and 106 may be connected to a communications network such as communications network 120 . Communications network 120 may represent: 1) a local area network (LAN); 2) a simple point-to-point network (such as direct modem-to-modem connection); and/or 3) a wide area network (WAN), including the Internet and other commercial based network services.
[0031] Cash recyclers 102 , 104 , and 106 may communicate with one another or with a financial institution such as bank 130 via communication network 120 in ways that are well known in the art. The existence of any of various well-known protocols, such as TCP/IP, Ethernet, FTP, HTTP, BLUETOOTH, Wi-Fi, ultra wide band (UWB), low power radio frequency (LPRF), radio frequency identification (RFID), infrared communication, IrDA, third-generation (3G) cellular data communications, Global System for Mobile communications (GSM), or other wireless communication networks or the like may be used as the communications protocol. Communications network 120 may be directly connected to a financial institution such as bank 130 . In another embodiment, communications network 120 may be connected to a second network or series of networks 140 such as the STAR network before being connected to bank 130 .
[0032] FIG. 2 illustrates a simplified diagram of a cash recycler in accordance with an aspect of the invention. Cash recyclers may comprise memories ( 108 , 112 , and 116 ) processors ( 210 , 212 , and 214 ), displays ( 204 , 206 , and 208 ), and communication interfaces ( 232 , 234 , and 236 ). The processors 210 , 212 , and 214 may execute computer-executable instructions present in memory 108 , 112 , 116 such that, for example, the cash recyclers 102 , 104 , and 106 may send and receive information to and from bank 130 via network or networks 120 and/or 140 . Bank 130 may utilize an infrastructure which includes a server 231 having components such as memory 158 , processor 160 , display 248 , and communication interface 250 . The memory for each of the cash recyclers 102 , 104 , and 106 and server 231 may include non-volatile and/or volatile memory.
[0033] FIG. 3 illustrates various features of cash recycler 102 used in various aspects of the invention. The images in FIG. 3 depict use of a single cash recycler 102 in a retail environment. The retail owner may have a cash recycler 102 located in each of their stores. In an aspect of the invention, summary information for the retail owner's stores may be available via an interface to the financial institution. In another embodiment, access to summary information may be available directly from each of the cash recyclers 102 .
[0034] In FIG. 3 , image 302 depicts customer 303 paying cash to store cashier 305 for a purchase. Another store cashier 307 at a recently closed cash register may be carrying a cash drawer or till 308 to a back office for reconciliation. In image 310 , store cashier 307 may load currency from cash register till 308 into cash recycler 102 . In addition, store cashier 107 may also deposit other paper forms of payment received from customer such as checks. An office manager 311 may be supervising cashier 307 during the loading of cash register till 308 into cash recycler 102 . Moreover, upon the start of a shift a cashier may fill his/her cash register till with a designated amount of currency dispensed from cash recycler 102 .
[0035] In image 306 of FIG. 3 , a display screen 204 of cash recycler 102 may show the total amount entered into cash recycler 102 from till 308 . The display screen 204 may breakout the amount entered into cash recycler 102 by denomination and by each cashier. The total amount deposited and withdrawn from cash recycler 102 may be shown on display screen 204 .
[0036] FIG. 4 illustrates additional features of cash recycler 102 used in various aspects of the invention. In image 402 of FIG. 4 , an armored car driver 403 may be delivering or picking up currency cylinders 405 from cash recycler 102 . The currency cylinders may contain a predetermined amount of currency in various denominations to be used by cash recycler 102 . As cash recycler 102 reuses currency that has been deposited via cashiers and/or other supervisory personnel for withdrawals, the frequency of armored car drop-offs of currency may be intermittent.
[0037] Image 406 illustrates reports 407 that may be generated showing various data such as the amount placed into cash recycler 102 along with the corresponding currency denominations. The reports 407 may also include information which may be used to determine when an armored car pickup should be scheduled.
[0038] The information stored in cash recycler 102 may be transmitted via network 120 to a financial institution for use in crediting or debiting various customer accounts. The retail customer may have access to the information through the financial institution's network. For example, image 408 depicts an enterprise employee accessing summary information concerning the businesses cash position as reported by the cash recyclers. The cash position of the enterprise may provide information to the enterprise employee directly via the interface or indirectly via another system authorize short term borrowing or investing, pay down credits lines, or request additional credit. Furthermore, the information may enable the enterprise employee to forecast future cash surpluses and shortages and/or perform other actives involving financial risk management.
[0039] FIG. 5 illustrates an interface screen that an enterprise employee may utilize to access information regarding the current cash position of the enterprise in accordance with an aspect of the invention. In FIG. 5 an interface screen 502 may be used to request that a user enter a name 504 and password 506 to verify authorization to use the system. After access authorization has been granted the user is given access to the system.
[0040] In an aspect of the invention, the user may decide to make a withdrawal to fill a cash register till. In FIG. 6 , a withdrawal screen 602 may be presented to the user in accordance with an aspect of the invention. The user, through a series of dropdown boxes, may request that a certain total amount be withdrawn from the cash recycler in requested denominations. For example in screen 602 , the user has requested that a total of $1,000 U.S. dollars 616 be withdrawn from cash recycler 102 . The user has further requested that the cash recycler 102 dispense the $1,000 dollars in the form of eight $100 dollar bills ( 604 ), three $50 dollar bills ( 606 ), one $20 dollar bill ( 608 ), two $10 dollar bills ( 610 ) and two $5 dollar bills ( 612 ). Upon entry of the appropriate amount the user may select button 618 or shortcut key F1 to initiate the withdrawal. After the currency has been dispensed by the cash recycler 102 , the cash recycler 102 may communicate with the financial institution or bank 130 to debit the appropriate enterprise accounts.
[0041] As shown in withdrawal screen 602 additional buttons or short cut keys corresponding to different functions may be displayed to the user. For example, the buttons may include a “Deposit” button 620 , a “Change” button 622 , a “Count” 624 , a “Totals” button 626 , a “Start Day” button 628 , an “End of Day” button 630 , an “ATS Counters” button 632 , an “ATS Status” button 634 , an “ATS Reset” button 636 , and a “Log off” button 638 .
[0042] When the currency has been dispensed from the cash recycler 102 , a displayed receipt may be shown to the user. For example, FIG. 7 illustrates a user screen 702 listing details in the form of receipt 704 for viewing by the user in accordance with an aspect of the invention. The user may request that the displayed receipt be printed 706 .
[0043] In another aspect of the invention, the user may deposit a cash register till into cash recycler 102 . The user may first count the currency and enter the amount into the cash recycler 102 . The cash recycler may tally the currency as it is being deposited and also check for potential counterfeit currency. After entry of the contents of the till into the cash recycler 102 , the amount entered by the user may be compared to the amount counted by cash recycler 102 . If the amounts are equal, the cash recycler 102 may communicate with the financial institution or bank 130 to credit the appropriate enterprise accounts. If a discrepancy exists, the user may be prompted to verify their count or a supervisor may be requested to intervene. Upon resolution, the cash recycler 102 may communicate with the financial institution or bank 130 to credit the appropriate enterprise account.
[0044] FIG. 8 illustrates a user screen 802 listing details for viewing by the user in accordance with an aspect of the invention. For example, user screen 802 may provide details of the transaction 804 along with detailed source amount information 806 and a breakdown of the currency denominations 808 .
[0045] In another aspect of the invention, the currency recycler 102 may also provide an inventory report 904 of the currency denominations 906 available to be dispensed upon request as illustrated in FIG. 9 . The information may also include other types of currency currently available to be dispensed by cash recycler 102 such as foreign currency.
[0046] FIG. 10 illustrates an interface screen, which may be used by an enterprise user to review cash balances at each of their stores or locations in accordance with an aspect of the invention. As shown in image 1002 , the user may tab to a treasury screen 1003 . The treasury screen 1003 may include a link to access online statements and reports 1004 , global information reporting 1006 and continuous linked statements 1008 . The user may have the ability to select a particular account service 1010 , make an account transfer 1012 , initialize information reporting 1014 , and/or initialize a transaction investigation 1016 .
[0047] In another aspect of the invention, standard reports 1018 may be available for review by the user. Additional detailed information may also be available by selecting different tabs such as a “Payments” tab 1020 , a “Receipts” tab 1024 , a “Trade” tab 1026 , and a “Notification” tab 1028 .
[0048] FIG. 11 illustrates a report that may be generated in accordance with an aspect of the invention. In FIG. 11 , a report is illustrated in image 1102 . For example, the report may be for a grocery chain called “Innovative Groceries” 1104 . The report may provide the user with the current day cash position for the grocery chain. For example, image 1102 illustrates a report which shows information 1108 and 1110 relating to cash positions at two stores 1109 and 1111 . A total cash position for the grocery chain may also be provided along with other information at 1112 .
[0049] The prompt recognition and acknowledgement of cash receipts may enable the enterprise to use the information to provide better funds management. For instance, the enterprise may decide to invest or pay down short term revolvers. Alternatively the enterprise may use the information to improve or mange cash change orders. The information may also be used in estimating and predicting future needs for lines of credit or in estimating future cash surpluses and/or shortages.
[0050] FIG. 12 illustrates a system configuration that may be used in accordance with an aspect of the invention. In FIG. 12 a cash recycler 1202 may communicate information to cash recycler service 1204 located at a remote location. For example, cash recycler 1202 may communicate deposit and withdrawal information from an enterprise location to the remote cash recycler service 1204 . The information may be routed through various networks such as the Internet to reach the cash recycler service. The cash recycler service 1204 may be located in the data center of a financial institution. The cash recycler service 1204 may communicate with an integration system 1206 which provides access to the financial systems and processes. The integration system 1206 may communicate with a memo posting system 1208 which may perform posting activity. The posting system 1208 may update the appropriate DDA (direct deposit account) system 1210 to reflect the balance changes in the enterprises account balances. The DDA system 1210 may also update a transaction repository 1212 for historical and intra-day reporting purposes. An enterprise employee may access information stored in the transaction repository 1212 through a client access channel 1214 via web browser. Those skilled in the art will realize that the financial institution may allow the enterprise user to access the information stored in the transaction repository via numerous alternative communication methods.
[0051] FIG. 13 illustrates a method of providing immediate credit to amount deposited in accordance with an aspect of the invention. In step 1302 , an enterprise employee may deposit a first amount of currency in a cash recycler. The cash recycler may accept different forms of currency including bills, coins, and checks. The cash recycler in step 1304 may determine the amount of currency deposited by the enterprise employee. The cash recycler may query the enterprise employee to acknowledge the determined amount of currency to be deposited before proceeding. In step 1306 , the cash recycler may transmit information relating to the amount of currency deposited to a financial institution. The financial institution upon receipt of the transmitted information may access the account of the enterprise and update the balance by the amount of the deposit. The financial institution may transmit an acknowledgement that the enterprise account has been updated. In step 1308 , the cash recycler may receive an acknowledgement of the deposit. In step 1310 , the enterprise may have immediate availability to the amount deposited to the account.
[0052] Although not required, one of ordinary skill in the art will appreciate that various aspects described herein may be embodied as a method, a data processing system, or as a computer-readable medium storing computer-executable instructions. Accordingly, those aspects may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. In addition, various signals representing data or events as described herein may be transferred between a source and a destination in the form of electromagnetic waves traveling through signal-conducting media such as metal wires, optical fibers, and/or wireless transmission media (e.g., air and/or space).
[0053] Aspects of the invention have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps illustrated in the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure.
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Aspects of the invention provide for an end-to-end currency handling, and servicing apparatus. The apparatus may be used in any cash-centric business or enterprise for cash register till set up and balancing, back office reconciliation, and other cash payment handling activities. Further aspects of the invention provide real-time access to cash receipts for enterprise use in making financial and planning decisions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of PCT International Application No. PCT/US06/060577 filed Nov. 6, 2006 which claims the benefit of U.S. Provisional Patent Application Ser. Nos. 60/733,842, filed on Nov. 4, 2005, entitled “A Scalable, Self-Routed, Terabit Capacity, Photonic Interconnection Network” and 60/734,890, filed on Nov. 9, 2005, entitled “Utilizing Path Diversity in Optical Packet Switched Interconnection Networks,” which are hereby incorporated by reference in their entirety herein.
BACKGROUND OF THE INVENTION
1. Technical Field
The disclosed subject matter relates to an optical network having one or more photonic switching nodes.
2. Background Information
Contemporary high performance computing (HPC) systems typically use the distributed shared memory (DSM) paradigm, wherein the entire memory is logically shared among all the processors but may be physically implemented using memory modules distributed across many computing nodes. This approach simplifies programming, provides portability of software, and exhibits improved scalability over traditional shared memory systems. Large scale DSM systems, however, suffer from a fundamental communication problem that significantly affects scalability: increased latency of remote memory accesses. The remote access latency problem is becoming critically more pronounced with faster processor speeds as each memory access consumes a correspondingly larger number of clock cycles.
Interconnection networks with low latency and high bandwidth have therefore become an important component in the design of HPC systems. Cutting-edge electronic transmission technologies, such as Hyper-transport and PCI-Express, as well as high performance cross-point switching fabrics are currently used to construct such networks. However, a performance gap is beginning to emerge between the processors, whose performance scales quickly according to Moore's law, and the interconnecting medium which fails to advance at a commensurate rate due to fundamental physical limitations. Dynamic power consumption, wiring density, and signal distortion are fundamental impediments to the scaling of electronic interconnection networks. Additionally, transmission of signals at high data rates (e.g., in excess of 1 Gb/s) over long electronic transmission lines (e.g., longer than 1 m) results in signal distortion which makes decoding these signals difficult or requires great amounts of power, large chip area, and high cost to ensure correct detection. Sophisticated signal processing techniques, such as pre-emphasis and equalization, can mitigate these effects to some extent, but they add to the overall latency and are expensive both in power and area. An alternative approach is to use relatively short transmission lines and an indirect topology such as a mesh or a torus, based on low-radix routers, but this approach leads to further increases in the overall latency as each packet has to traverse a larger number of hops.
Photonic interconnection networks are a potentially transformative technology with the capability to overcome these limitations and provide commensurate performance scaling. The enormous bandwidth of optical fibers, approximately 32 THz, facilitates the transmission of multiple data streams on a single fiber at very high data-rates using wavelength division multiplexing (WDM). The low loss in fibers, nearly zero for the distances relevant to interconnection networks, alleviates the need for regeneration and effectively removes the signal transmission limitation. The photonic medium also allows for bidirectional transmission and switching of high-rate data using optical switching elements completely transparent to the modulated data, a property known as bit-rate transparency. Semiconductor optical amplifiers (SOAs) are used in several experimental optical packet switching systems as on-off photonic gates, providing a substantial gain over a wide switching band, and sub-ns switching times.
Photonic technology presents, however, some fundamental design challenges specifically in its lack of efficient buffering and processing capabilities. Although some promising technologies such as photonic crystals are being investigated and may prove useful in constructing photonic memories and logic gates, they have failed to reach commercialization thus far. Optical buffers based on recirculating fiber delay lines have been demonstrated as have interferometeric optical logic gates but their dimensions and “bulkiness” prohibit them from becoming cost-effective solutions.
An impediment to the construction of photonic interconnection networks lies in the high cost and large footprints associated with using discrete optical elements such as lasers, modulators, switches and passive optics. Photonic integration, the fabrication of circuits implementing multiple photonic functions in a single package, is promising to eliminate these final barriers. Since the elements comprising the prohibitive cost of optical networks mainly lie in the assembly and packaging of very large systems, and a significant share of the power consumption rises from coupling losses between individually packaged devices, integration of large parts of the network on a single photonic integrated circuit (PIC) alleviates these factors. Monolithic Indium-Phosphide PICs containing 50 photonic functions have been reported in scientific literature and are now commercially available. Additionally, silicon-based optical and electro-optical components such as modulators, photodetectors, and waveguides, all compatible with standard (CMOS) processing techniques have recently become available, promising an unprecedented potential for low cost electronic-optical interfacing.
When photonic integration is harnessed to construct interconnection networks, however, buffering becomes very difficult. The optical packet typically occupies a fixed length of a waveguiding medium which is the product of the speed of light in the medium and the duration of the packet. The size of optical packets known in the art occupy a certain amount of space, such that it is difficult, if not impossible, to fit on an integrated circuit. For example, a typical 100-ns packet will occupy 20 meters of silica fiber or 6 meters of a semiconductor waveguide. Consequently, buffering optical packets within a PIC is not currently practical.
Accordingly, there is a need in the art to provide a scalable interconnection network based on photonic integration that offers a bufferless means of contention resolution.
SUMMARY OF THE INVENTION
An optical network is disclosed comprising one or more photonic switching nodes, each of which, comprises a plurality of input ports; at least one output port; and a switch configured to route messages between the plurality of input ports and the at least one output port and provide bufferless resolution of contention between messages for a common output port.
In some embodiments, the switch selects a first message in the case where two or more messages contend for a common output port. In some embodiments, the switch drops a second message in the case where two or more messages contend for a common output port. In some embodiments, the switch selects said first message randomly, according to an alternating scheme, or according to priority information encoded in said messages.
In some embodiments, the optical network may further include a source terminal and a destination terminal, wherein the photonic switching nodes transmit a first message on a path from said source terminal to said destination terminal. The destination terminal may transmit an acknowledgment signal to the source terminal of a message upon receipt of said message at its requested output port. In some embodiments, the photonic switching nodes transmit said acknowledgement signal on said path from said destination terminal to said source terminal. The optical network may retransmit the message in the case where an acknowledgment signal is not received. In some embodiments, the optical network retransmits the message in the case where an acknowledgment signal is not received prior to the end of a slot.
In some embodiments, the switch comprises a programmable logic device. The photonic switching nodes may be interconnected in a Banyan topology. The photonic switching nodes may be interconnected in an Omega topology.
In some embodiments, the message comprises routing information at a first wavelength and data at a second wavelength. The switch may comprise wavelength filters associated with said first wavelength and said second wavelength.
In some embodiments, the optical network may comprise one or more scattering nodes. The one or more photonic switching nodes and one or more scattering nodes may transmit the first message on a path from the source terminal to the destination terminal. The destination terminal may transmit an acknowledgment signal to the source terminal of a message upon receipt of the message at its requested output port. The one or more photonic switching nodes and one or more scattering nodes may pass said acknowledgement signal on said path from said destination terminal to said source terminal.
The optical network may further include a distribution network comprising one or more distribution stages for routing messages comprising a distribution address. The source terminal changes the distribution address of a message prior to retransmission. In some embodiments, transmission in the optical network is synchronous. In some embodiments, the optical network is slotted.
A method is provided for transmitting messages through an optical network. A network comprising one or more photonic switching nodes for transmitting messages therethrough is provided. One or more messages is received at one or more input ports of a photonic switching node, each message comprising routing information relating to a requested output port. In the case of two or more messages contending for a common output port, bufferless contention resolution of contention between messages for a common output port is provided. The messages are transmitted through the network.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the disclosed subject matter will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments of the disclosed subject matter, in which:
FIG. 1 is a diagram representing a network of switching nodes in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 2 is a diagram representing a switching node in accordance with an exemplary embodiment of the disclosed subject matter.
FIGS. 3A to 3F are diagrams representing switching states of a switching node in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 4 is a diagram representing a message transmitted through the network in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 5 is a diagram representing a message dropped by a switch in the network in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 6 is a diagram representing the wavelength distribution of a message in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 7 is a diagram representing a node in the network in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 8 is a diagram representing a switching network in accordance with another embodiment of the disclosed subject matter.
FIGS. 9-10 are diagrams representing nodes in a network illustrated in FIG. 8 in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 11 is a diagram representing a switching network in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 12 is a diagram representing a switching network in accordance with an exemplary embodiment of the disclosed subject matter.
FIG. 13 is a diagram representing a switching network in accordance with an exemplary embodiment of the disclosed subject matter.
Throughout the figures, the same reference numerals and characters are used to denote like features, elements, components or portions of the illustrated embodiments, unless otherwise stated.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
In an exemplary embodiment of a scalable photonic integrated network, port-to-port optical packets (messages) can be self-routed through an optical multistage interconnection network. The network may be constructed from 2×2 photonic switching nodes, while the payload is maintained in the optical domain across the network. The messages may be constructed in a manner according to wavelength division multiplexing to achieve high bandwidth and simplify the node design.
FIG. 1 illustrates a scalable photonic integrated network 100 . In an exemplary embodiment, the network is a binary butterfly-class multistage interconnection network, comprised of 2×2 photonic wideband switching nodes 10 . FIG. 1 shows a scalable photonic integrated network 100 implemented in an Omega topology, but the specific topology can encompass other implementations, such as Banyan, Butterfly, 4-cube, and Baseline.
The system shown in FIG. 1 may be synchronous and slotted. The messages are constructed in the source terminals 110 and are transmitted on optical fibers or optical waveguides 114 into the network 100 .
For a slot, messages start propagating substantially simultaneously in the network 100 . According to an exemplary embodiment, messages may be self-routed. Such messages include information regarding an intended destination terminal. The intended destination terminal may or may not be the message's ultimate destination. At a switching node 10 , when a leading edge of a message is received, a routing decision is made, and the message continues to propagate to its requested output port 14 . Output port contention may occur, for example, when two messages arrive at a node and request the same output port. In such case, one of the contending messages is transmitted, and one (or more) contending messages is dropped. The choice of which message to drop may be, for example, random, alternating or priority-based. For example, in a priority-based scheme, priority information may be encoded on a specific wavelength in the message. The switching node may decode such information and use it to make the routing decision so that the message with the higher priority is transmitted and the message with the lower priority is dropped. In an exemplary embodiment, the propagation delay through every stage may be substantially identical, such that the leading edges of the transmitted messages reach all the nodes 10 of each stage at the same time.
FIG. 2 illustrates a 2×2 photonic wideband switching node 10 with input ports 12 and output ports 14 . A switch path 16 is established between an input port 12 and an output port 14 .
FIGS. 3A to 3F illustrate the 6 states of a switching node 10 . FIG. 3A illustrates an interchange state 20 in which an upper-to-lower switch path 16 a is established between the upper input port 12 a and the lower output port 14 b and a lower-to-upper switch path 16 b is established between the lower input port 12 b and the upper output port 14 a . FIG. 3B illustrates a straight state 22 in which an upper straight switch path 16 c is established between the upper input port 12 a and the upper output port 14 a and a lower straight switch path 16 d is established between the lower input port 12 b and the lower output port 14 b . FIG. 3C illustrates an upper straight state 24 in which only an upper straight switch path 16 c is established between the upper input port 12 a and the upper output port 14 a . FIG. 3D illustrates an upper exchange state 26 in which only an upper-to-lower switch path 16 a is established between the upper input port 12 a and the lower output port 14 b . FIG. 3E illustrates a lower straight state 28 in which only a lower straight switch path 16 d is established between the lower input port 12 b and the lower output port 14 b . FIG. 3F illustrates a lower exchange state 30 in which only a lower-to-upper switch path 16 b is established between the lower input port 12 b and the upper output port 14 a . As will be understood by one of ordinary skill in the art, additional and/or different states may be provided for nodes having a different number of input or output ports. Further, the terms “upper” and “lower” as used in FIGS. 3A-3F to describe input and output ports are used for convenience of description only, and will generally be understood to refer to a “first” and a “second” port.
FIG. 4 illustrates that the switching states (e.g., states 20 - 30 illustrated in FIGS. 3A-3F ) of the switching nodes 10 , as determined by leading edges, remain constant throughout the duration of the message, e.g., throughout a slot, so the entire message follows each switch path 16 acquired by the leading edge, effectively creating a transparent lightpath 200 between the source terminal 110 and destination terminal 112 . When the messages reach their destinations, an acknowledgement optical pulse (“ack pulse”) is generated at the destination terminal and sent on the same transparent lightpath 200 in the opposite direction. Owing to the bidirectionality of the switching nodes 10 , the acknowledgement pulses are transmitted along the lightpath 200 to the appropriate source terminals 110 .
When the slot time is over, all source terminals 110 and destination terminals 112 may cease transmission simultaneously, the switching nodes 10 reset their switching states 20 - 30 , and the system is ready for a new slot. The slot duration may be set so that the ack pulses are received at the source terminal 110 before the slot ends, allowing every source terminal 110 to determine whether its message was successfully transmitted and make a timely decision regarding its retransmission in the case that the message was dropped. This physical-layer acknowledgement mechanism allows the source terminals 110 to regard the dropped messages as blocked messages and avoid the penalty associated with packet recovery at higher layers.
FIG. 5 illustrates a condition in which two messages contend for the same output port 14 a of node 10 a . The message originating from source terminal ( 0 ) 110 a , traveling on lightpath 200 a , is transmitted to destination terminal 112 a . The message originating from source terminal ( 6 ) 110 b , traveling on lightpath 200 b , is dropped. Destination terminal ( 0 ) 112 a transmits an acknowledgement signal on lightpath 200 a to source terminal ( 0 ) 110 a . Source terminal ( 6 ) 110 b receives no acknowledgement signal and prepares to retransmit its message.
According to an exemplary embodiment, the wavelength domain is used to facilitate a routing mechanism in the switching nodes 10 that can instantaneously determine and execute the routing decision upon receiving the messages' leading edges, and maintain a constant switching state 20 - 30 throughout duration of the messages. As shown in FIG. 6 , the messages 300 are constructed in a wavelength-parallel manner, i.e., the routing header bits 310 and the payload 320 may be encoded on separate wavelengths and are received substantially concurrently by the switching nodes 10 . The header bits 310 comprise a frame bit 312 , denoting the existence of the message, and a destination address tag 314 , which is comprised of address bits 316 . Each of the header bits, encoded on a dedicated wavelength, remains constant throughout the message. According to an exemplary embodiment, a single address bit 316 is processed at every stage, so the number of wavelengths required for address encoding is log 2 of the number of output ports. Segmenting the payload 320 and encoding on multiple wavelengths utilize the large bandwidth offered by wavelength division multiplexing.
Butterfly networks may be used in the scalable photonic integrated network 100 because their binary nature facilitates the usage of destination tag routing and simple decision rules that are desirable for ultra-low latency optical switching. When messages originating from different input ports may contend for the same output ports, the process of implicit arbitration through self-routing also eliminates the need for a central arbitration mechanism thus allowing the system to scale to large port-counts. However, these blocking networks will have a lower throughput than non-blocking networks, in which a disjoint path exists between each pair of input/output terminals. Contention avoidance techniques and topological modifications as well as input speedup can be utilized to increase the message acceptance rate.
According to an exemplary embodiment, a large number of switching nodes 10 may be implemented on a single PIC. Commercially available optoelectronic elements such as semiconductor optical amplifier (SOA) gates and photodetectors may be used. For example, SOAs offer the uniform gain curve, sub-ns switching time and low latency required from electronically controlled optical switching gates in a switching node 10 .
FIG. 7 illustrates one exemplary embodiment of the switching node. Switching node 10 includes a switch which routes messages received at input ports 12 a and/or 12 b to output ports 14 a and 14 b . Further, the switch selects a message for transmission to its requested output port as will be described in greater detail below. The switch may be comprised of semiconductor optical amplifier gates (SOAs) 502 , optical couplers 400 and 402 , wavelength filters 404 and 406 , p-i-n receivers 504 , optical fibers 410 , and a programmable logic device 506 . These elements may be connected together using optical fiber or waveguides 410 , depending on the implementation. Any of these elements may be substituted with other elements or rearranged as is known to one of skill in the art. When messages enter the switching node 10 at input ports 12 a and/or 12 b , the relevant header bits 310 (frame bit 312 , denoting message existence, and a relevant address bit 316 ) are optically extracted from both messages using frame wavelength filters 404 and address wavelength filters 406 , detected, and forwarded to an electronic control circuit 506 . The control circuit 506 , e.g., a Xilinx complex programmable logic device (CPLD) in the exemplary embodiment, makes the routing decision and activates the appropriate SOAs (or SOA) 502 to create the required input-output path. The messages, delayed on optical fibers 410 , reach the SOAs 502 exactly when they are activated and are routed appropriately. The routing decision as to whether to transmit contending messages is determined by the control circuit 506 .
Topological modifications in the network can be used to increase the acceptance rate. FIG. 8 illustrates another exemplary embodiment of a network, which is substantially identical to network 100 , with the relevant differences noted herein. Network 600 may include one or more scattering nodes 602 , which have an input port 12 and an output port 14 , as illustrated in FIG. 9 . The Enhanced Omega 600 network shown in FIG. 8 mitigates internal contentions by adding scattering stages 610 before the routing stages 620 . Scattering stages 610 are formed by the insertion of scattering nodes 602 before the Omega switching nodes 620 . The scattering nodes 602 identify messages that will contend for the same output port in the subsequent switching stage and scatter them to different switching nodes. Scattering nodes misroute contending messages rather then drop them, letting the subsequent switching node route them correctly. By adding additional possible routes, the addition of scattering nodes allows more messages to be successfully transmitted, and fewer messages dropped.
FIG. 10 illustrates how the connection patterns between the scattering stage 610 and the routing stage 620 complete the scattering action while ensuring that even misrouted messages reach their original destinations. Messages are only scattered between switching nodes 10 that lead to the same part of the network in subsequent stages.
The scattering nodes 602 cannot be placed before the last stage of the Omega network 600 , because in this stage scattering will cause routing errors. Therefore, a maximum of N S −1 scattering stages can be added to a network of N S routing stages, increasing its number of stages to 2N S −1.
According to another exemplary embodiment, a network of scattering nodes may be inserted before a routing network to serve as a distribution network. A distribution network routes messages to different input ports of a routing network in a manner that minimizes contentions. Additional address bits carry the distribution address, which determines the path taken through the distribution network. The routing network follows the distribution network to ensure correct routing functionality is intact.
The exemplary embodiment may provide several advantages. First, a random route may be chosen in the distribution network by encoding a random distribution address, balancing the load on the routing network regardless of the real traffic pattern. Second, exploiting the physical layer acknowledgement protocol and path diversity, path adjustment may be made by changing the distribution address if the message is dropped in the first attempt. These path adjustments may be made in several iterations within the same timeslot, during the guardband that precedes the payload transmission. Each iteration takes as long as the sum of the roundtrip time across the network and the response time of the acknowledgment generation modules, so the number of iterations may be a design parameter balancing the added utilization gained from multiple iterations and time that can be allocated to path adjustments.
FIGS. 11-13 illustrate the advantages of a distribution network in accordance with an exemplary embodiment. In FIGS. 11-13 , four messages are transmitted: messages 300 a (from source terminal 110 a to destination terminal 112 a ), 300 b ( 110 b to 112 b ), 300 c ( 110 c to 112 c ), and 300 d (from 110 d to 112 d ). FIG. 11 illustrates two messages 300 c and 300 d are dropped due to internal path contentions in an Omega network 100 . FIG. 12 illustrates one embodiment of a network that comprises a distribution network 700 . By adding a distribution network 700 and routing the messages 300 through it according to a random distribution of addresses, message 300 d takes a different path 200 d and is transmitted successfully. Message 300 c is still dropped, so when the acknowledgment pulse does not arrive on time, source terminal 110 c encodes a new distribution address on message 300 c . FIG. 13 illustrates how a new distribution address forces message 300 c to take a different path 200 c at node 602 a that resolves the contention. In this manner, the path adjustment technique may use the ultra-low latency of the integrated interconnection network and the distributed computing power of the switching nodes, to increase the network utilization by resolving contentions in the space domain.
The acceptance rate of the path-diversified scalable photonic network has been investigated on a representative 64×64 Omega network with a distribution network. Simulations were run using Bernoulli iid traffic with a varying p parameter (offered load). In the first performance study, the immunity for adversarial traffic patterns was shown by simulating bit-reversal traffic patterns, chosen as adversarial patterns for the Omega network. As expected, adding distribution stages increased the path diversity and performance, but with a diminishing rate.
The effect of the path adjustments was investigated in a network simulated with 0 to 4 path adjustment iterations, under uniform traffic. The performance improvement was substantial, effectively pushing the performance curve closer to the upper boundary represented by a non-blocking network (that would require 4096 switching nodes). The performance improvement beyond two iterations diminished so that two iterations seem to be a good trade-off point, considering the time limitation.
Whereas a non-distribution network switching node may include a gate array as the logic circuit, the node in a distribution network, such as network 700 , toggles between several states to avoid interference between messages whose paths are being adjusted and messages that are already successfully routed, i.e., the switching nodes ensure that messages whose transmission has begun will not suffer from interference from messages whose paths are being adjusted. According to an exemplary embodiment, nodes in a distribution network may be implemented as state machines that encode three states for path protection: idle, bar, and cross. When no message is routed through the node, it is in the “idle” path-protection state. When one or more messages is routed through an “idle” node, its path-protection state changes from “idle” to either “cross” or “bar,” according to the selected switching state encoded on a message. For example, if interchange switching state 20 is selected, then the node's path-protection state will change to “cross,” and if straight switching state 22 is selected, the node's path-protection state will change to “bar.” When the node is in the “cross” or “bar” path-protection state (i.e. currently handling a message) and a subsequent message is received (e.g., after has its path has been adjusted), the subsequent message will be passed only if its requested output port matches the current path-protection state (i.e. does not require a state change). If the new message requires a state change, it will be dropped. Once a node is in the “cross” or “bar” path-protection state, it may remain in that state until the message that triggered the state is over. During that time, the node may route messages that are not contending with the original message, while messages that are contending are blocked or dropped. When the slot is over and all messages have been transmitted, the node switches back to the “idle” state and is ready to receive new messages. Error-free transmission of 16×10 Gb/s wavelength-parallel messages has been confirmed for a switching node with three path-protection states.
The average bandwidth routed by a scalable photonic integrated network can be calculated from simulation results. For example, a 64-port Enhanced Omega network, operated at 0.8 offered load, may attain 0.52 acceptance rate. The normalized throughput is therefore 0.8·0.52=0.42. Operation with a 160 Gb/s wavelength-parallel payload (16×10 Gb/s) yields an average throughput of 67 Gb/s per port and 4.26 Tb/s system total average throughput.
The functionality of the switching node and scalable photonic integrated network have been experimentally verified using an optical testbed. Wavelength-parallel messages, consisting of 16 wavelengths modulated at 10 Gb/s, were constructed to create a total payload bandwidth of 160 Gb/s. The payload wavelengths spanned across 29 nm in the C-band, with a minimum spacing of 0.8 nm between adjacent channels, to show that more payload wavelengths could be straightforwardly added to increase the system's bandwidth. The messages were 97.6 ns long, spaced by a 4.8 ns dead time. Once constructed, the messages were multiplexed with the appropriate header wavelengths and injected into the experimental switching node through both input ports. At the node output ports correct routing was verified using an oscilloscope and bit error rate (BER) measurements were conducted on each wavelength individually. Ack pulses (9.6 ns long) were modulated externally on a dedicated wavelength and were injected into the output ports when messages are received. Full routing functionality of all nine possible input combinations (no-packet, packet-to-out0, packet-to-out1 per input port) has been verified in one experiment.
Error-free routing of the messages has been verified and a BER of 10 −12 or better has been confirmed on all 16 payload wavelengths. It has been shown for SOA-based multi-hop networks that after 58 hops, a 10 −9 bit error rate can still be maintained for 8 wavelengths, spanned across a functional bandwidth of 24.2 nm. As even large scalable photonic integrated networks are expected to have a significantly lower number of stages, (N S v log 2 N), a larger functional bandwidth can be attained.
It will be understood that the foregoing is only illustrative of the principles of the disclosed subject matter, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the disclosed subject matter as defined by the appended claims. Exemplary embodiments may be combined with other exemplary embodiments or modified to create new embodiments.
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An optical network is disclosed comprising one or more photonic switching nodes is disclosed. Each of the switching nodes comprises a plurality of input ports; at least one output port; and a switch configured to route messages between the plurality of input ports and the at least one output port and provide bufferless resolution of contention between messages for a common output port.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 09/651,949 filed on Aug. 31, 2003 now U.S. Pat. No. 6,678,840, which is hereby incorporated by reference herein.
This application relates to the following commonly assigned co-pending applications entitled:
“Apparatus And Method For Interfacing A High Speed Scan-Path With Slow-Speed Test Equipment,” Ser. No. 09/653,642, filed Aug. 31, 2000,“Priority Rules For Reducing Network Message Routing Latency,” Ser. No. 09/652,322, filed Aug. 31, 2000, “Scalable Directory Based Cache Coherence Protocol,” Ser. No. 09/652,703, filed Aug. 31, 2000, “Scalable Efficient I/O Port Protocol,” Ser. No. 09/652,391, filed Aug. 31, 2000, “Efficient Translation Lookaside Buffer Miss Processing In Computer Systems With A Large Range Of Page Sizes,” Ser. No. 09/652,552, filed Aug. 31, 2000, “Speculative Directory Writes In A Directory Based Cache Coherent Nonuniform Memory Access Protocol,” Ser. No. 09/652,834, filed Aug. 31, 2000, “Special Encoding Of Known Bad Data,” Ser. No. 09/652,314, filed Aug. 31, 2000, “Broadcast Invalidate Scheme,” Ser. No. 09/652,165, filed Aug. 31, 2000,“Mechanism To Track All Open Pages In A DRAM Memory System,” Ser. No. 09/652,704, filed Aug. 31, 2000, “Programmable DRAM Address Mapping Mechanism,” Ser. No. 09/653,093, filed Aug. 31, 2000, “Computer Architecture And System For Efficient Management Of Bi-Directional Bus,” Ser. No. 09/652,323, filed Aug. 31, 2000,“ An Efficient Address Interleaving With Simultaneous Multiple Locality Options,” Ser. No. 09/652,452, filed Aug. 31, 2000, “A High Performance Way Allocation Strategy For A Multi-Way Associative Cache System,” Ser. No. 09/653,092, filed Aug. 31, 2000, “Method And System For Absorbing Defects In High Performance Microprocessor With A Large N-Way Set Associative Cache,” Ser. No. 09/651,948, filed Aug. 31, 2000, “A Method For Reducing Directory Writes And Latency In A High Performance, Directory-Based, Coherency Protocol,” Ser. No. 09/652,324, filed Aug. 31, 2000, “Mechanism To Reorder Memory Read And Write Transactions For Reduced Latency And Increased Bandwidth,” Ser. No. 09/653,094, filed Aug. 31, 2000, “System For Minimizing Memory Bank Conflicts In A Computer System,” Ser. No. 09/652,325, filed Aug. 31, 2000, “Computer Resource Management And Allocation System,” Ser. No. 09/651,945, filed Aug. 31, 2000, “Input Data Recovery Scheme,” Ser. No. 09/653,643, filed Aug. 31, 2000, “Fast Lane Prefetching,” Ser. No. 09/652,451, filed Aug. 31, 2000, “Mechanism For Synchronizing Multiple Skewed Source-Synchronous Data Channels With Automatic Initialization Feature,” Ser. No. 09/652,480, filed Aug. 31, 2000, “Mechanism To Control The Allocation Of An N-Source Shared Buffer,” Ser. No. 09/651,924, filed Aug. 31, 2000, and “Chaining Directory Reads And Writes To Reduce DRAM Bandwidth In A Directory Based CC-NUMA Protocol,” Ser. No. 09/652,315, flied Aug. 31, 2000, and provisional application titled “Alpha Processor,” Ser. No. 60/229,412, filed Aug. 31, 2000, all of which are incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a multi-processor computer system. More particularly, the invention relates to fault isolation in a multi-processor computer system.
2. Background of the Invention
As the name suggests, multi-processor computer systems are computer systems that contain more than one microprocessor. Data can be passed from one processor to another to another in such systems. One processor can request a copy of a block of another processor's memory. As such, memory physically connected to or integrated into one processor can be shared by other processors in the system. A high degree of shareability of resources (e.g., memory) generally improves system performance and enhances the capabilities of such a system.
Resource sharing in a multi-processor computer system, although advantageous for performance, increases the risk of a data error propagating through the system and causing widespread harm in the system. For example, multiple processors may need a copy of a data block from a source processor. The requesting processors may need to perform an action dependent upon the value of the data. If the data becomes corrupted as it is retrieved from the source processor's memory (or may have become corrupted when it was originally stored in the source processor), the requesting processors may perform unintended actions. Hardware failures in one processor or logic associated with one processor may cause corruption or failures in other parts of the system. Accordingly, techniques for fault containment are needed.
Several fault isolation techniques have been suggested. One suggestion has been to allow controlled memory sharing in a system that is page-based and that relies on a processor with precise memory faults. Such a page-based technique is relatively complex to implement. Although acceptable in that context, a need still exists to isolate faults in a computer system that is easier to implement than a page-based technique. Further, it would be desirable to have an isolation strategy that works in a multi-processor system in which the processors do not have precise memory exceptions. Despite the advantages such a system would provide, to date no such system is known to exist.
BRIEF SUMMARY OF THE INVENTION
The problems noted above are solved in large part by a multi-processor computer system that permits various types of partitions to be implemented to contain and isolate hardware failures. The various types of partitions include hard, semi-hard, firm, and soft partitions. Each partition can include one or more processors. Upon detecting a failure associated with a processor, the connection to adjacent processors in the system can be severed, thereby precluding corrupted data from contaminating the rest of the system.
If an inter-processor connection is severed, message traffic in the system can become congested as messages become backed up in other processors. Accordingly, the preferred embodiment of the invention includes various timers in each processor to monitor for traffic congestion that may be due to a severed connection. Rather than letting the processor continue to wait to be able to transmit its messages, the timers will expire at preprogrammed time periods and the processor will take appropriate action, such as simply dropping queued messages, to keep the system from locking up. Each processor preferably includes individual timers for different types of messages (e.g., request, response). These and other advantages will become apparent upon reading the reviewing the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
FIG. 1 shows a system diagram of a plurality of microprocessors coupled together;
FIGS. 2 a and 2 b show a block diagram of the microprocessors of FIG. 1 ;
FIG. 3 shows a block diagram of the router logic used in the microprocessor of FIGS. 2 a and 2 b;
FIG. 4 shows timers for various message types used in the preferred embodiment of the invention;
FIG. 5 shows buffers associated with each of the message types shown in FIG. 4 ;
FIG. 6 shows various programmable registers used to implement the preferred embodiment of the invention;
FIG. 7 shows another programmable register used to implement the preferred embodiment of the invention; and
FIG. 8 shows various programmable registers used to implement the preferred embodiment of the invention.
NOTATION AND NOMENCLATURE
Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, computer companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 , in accordance with the preferred embodiment of the invention, computer system 90 comprises one or more processors 100 each preferably coupled to a memory 102 and an input/output (“I/O”) controller 104 . As shown, computer system 90 includes 12 processors 100 , each processor coupled to a memory and an I/O controller. Each processor preferably includes four ports for connection to adjacent processors. The inter-processor ports are designated “north,” “south,” “east,” and “west” in accordance with the well-known Manhattan grid architecture. As such, each processor 100 can be connected to four other processors. The processors on both end of the system layout wrap around and connect to processors on the opposite side to implement a 2D torus-type connection. Although 12 processors 100 are shown in the exemplary embodiment of FIG. 1 , any desired number of processors (e.g., 256) can be included.
The I/O controller 104 provides an interface to various input/output devices such as disk drives 105 and 106 as shown. Data from the I/O devices thus enters the 2D torus via the I/O controllers.
In accordance with the preferred embodiment, the memory 102 preferably comprises RAMbus™ memory devices, but other types of memory devices can be used if desired. The capacity of the memory devices 102 can be any suitable size. Further, memory devices 102 preferably are implemented as Rambus Interface Memory Modules (“RIMMS”).
In general, computer system 90 can be programmed so that any processor 100 can access its own memory 102 and I/O devices as well as the memory and I/O devices of all other processors in the network. Preferably, the computer system may have physical connections between each processor resulting in low interprocessor communication times and improved memory and I/O device access reliability. If physical connections are not present between each pair of processors, a pass-through or bypass path is preferably implemented in each processor that permits accesses to a processor's memory and I/O devices by another processor through one or more pass-through processors.
Fault isolation in the multi-processor system 90 shown in FIG. 1 is implemented by way of “domains.” A domain includes one or more processors 100 . Three exemplary domains, D 1 , D 2 , and D 3 , are shown in FIG. 1 . Each of the exemplary domains D 1 –D 3 shown in FIG. 1 includes four processors 100 . Messages can be routed between processors within a given domain. The preferred embodiment, however, treats cross boundary messages differently than intra-domain messages.
The domains of multiprocessor system 90 provide varying degrees of isolation and sharing of resources between domains. System 90 preferably permits the implementation of hard partitions, semi-hard partitions, firm partitions, and soft partitions. These partitions, defined below, are set up by programming various registers in each processor as explained below.
In a hard partition there is no communication between domains that are subject to the hard partition. In this way, corrupted data, for example, is simply not permitted to cross the domain boundary. Of course, uncorrupted data also is not permitted to cross the domain boundary.
A firm partition allows domains to share a portion of its memory. Accordingly, some of the memory within a given domain is designated as “local” while other memory is designated as “global.” As shown in FIG. 1 , each processor 100 preferably is coupled to a memory 102 . In a firm partition, a portion of memory 102 is local and another portion can be global. Further, local memory can also be designated as global. Local memory means memory locations that only the processors within the domain can access. That is, a processor is not permitted to access local memory associated with a processor in another domain. Global memory, on the other hand, can be accessed by processors outside the domain in which the memory is physically located.
A semi-hard partition is a firm partition with some additional restrictions and additional hardware reliability assurances. A semi-hard partition generally requires that all communication within a given domain must stay within the domain. Only sharing traffic to the “global” memory region may cross domain boundaries. Hardware failures in one domain can cause corruption or fatal errors within the domain that contains the error. Hardware failures in any domain can also corrupt the “global” region of memory. However, hardware failures in one domain will not corrupt the local memory of any other domains.
A soft partition allows for all communication to cross domain boundaries. The domain is strictly a software concept in this case. The partitions can share a “global” portion of memory. Each domain has a region of local memory that the other domains cannot access. What memory is global and which is local preferably is programmable. A hardware failure in one domain may cause corruption in any other domain in a soft partition. Various registers discussed below are used to set up a self memory partition.
The system 90 can be configured as described above to implement any one or more of the preceding types of partitions. The response of the system to a failure will now be described. Those failures (e.g., single bit errors) that can be corrected, preferably are corrected as the data is passed from one processor to another. The processors 100 preferably pack the data with error correction code (“ECC”) bits to permit detection and recovery of a single bit error in accordance with known techniques. Double bit errors preferably can be detected, but may not be able to be corrected. Data preferably is transmitted as “packets” of data (also referred to as “ticks”). If the first tick of a packet includes a double bit error, the entire message is discarded. If the double bit error occurs on one of the last ticks of a data packet being received by a processor, by the time the processor detects the presence of the error, the processor may have already begun forwarding the first ticks on to the next processor in the communication path. In this case the entire packet is sent, even if it contains the error. Regardless of which tick experienced the double bit error, both directions on the channel are placed into a state in which no transmissions are permitted to occur. For example, referring still to FIG. 1 , if processor 100 b detects a double bit error on a transmission from processor 100 a over channel 102 a , processor 100 b takes down the channel 102 a in both directions thereby severing the communication between processors 100 a and 100 b via channel 102 a.
Not only are communications initiated by processor 100 a and destined for processor 100 b effectively terminated, the same is true for any communication that would otherwise be transmitted across channel 102 a . Terminating a communication channel 102 involves disabling all output ports and ignoring all input signals. Disabling an output port includes stopping any clock signals that are otherwise necessary for the proper operation of the output port.
Although terminating a communication channel 102 effectively isolates a failure, because of the distributed, resource sharing nature of the multiprocessor system 90 , the terminated channel may cause undesirable traffic congestion. Messages that would otherwise have been routed through the now terminated channel back up which in turn causes other messages to back up as well. The problem is akin to an airport that is unusable due to a rain storm for example that causes a rippling effect in other airports as air traffic begins to congest.
The preferred embodiment of the invention uses various timers to solve this problem. These timers preferably are included in each processor 100 . The following description of FIGS. 2 a and 2 b describe a preferred embodiment of the processor. Following this general description of processor 100 , the use of the timers will be described.
Referring now to FIGS. 2 a and 2 b , each processor 100 preferably includes an instruction cache 110 , an instruction fetch, issue and retire unit (“Ibox”) 120 , an integer execution unit (“Ebox”) 130 , a floating-point execution unit (“Fbox”) 140 , a memory reference unit (“Mbox”) 150 , a data cache 160 , an L 2 instruction and data cache control unit (“Cbox”) 170 , a level L 2 cache 180 , two memory controllers (“Zbox0” and “Zbox1”) 190 , and an interprocessor and I/O router unit (“Rbox”) 200 . The following discussion describes each of these units.
Each of the various functional units 110 – 200 contains control logic that communicate with various other functional units control logic as shown. The instruction cache control logic 110 communicates with the Ibox 120 , Cbox 170 , and L 2 Cache 180 . In addition to the control logic communicating with the instruction cache 110 , the Ibox control logic 120 communicates with Ebox 130 , Fbox 140 and Cbox 170 . The Ebox 130 and Fbox 140 control logic both communicate with the Mbox 150 , which in turn communicates with the data cache 160 and Cbox 170 . The Cbox control logic also communicates with the L 2 cache 180 , Zboxes 190 , and Rbox 200 .
Referring still to FIGS. 2 a and 2 b , the Ibox 120 preferably includes a fetch unit 121 which contains a virtual program counter (“VPC”) 122 , a branch predictor 123 , an instruction-stream translation buffer 124 , an instruction predecoder 125 , a retire unit 126 , decode and rename registers 127 , an integer instruction queue 128 , and a floating point instruction queue 129 . Generally, the VPC 122 maintains virtual addresses for instructions that are in flight. An instruction is said to be “in-flight” from the time it is fetched until it retires or aborts. The Ibox 120 can accommodate as many as 80 instructions, in 20 successive fetch slots, in flight between the decode and rename registers 127 and the end of the pipeline. The VPC preferably includes a 20-entry table to store these fetched VPC addresses.
The branch predictor 123 is used by the Ibox 120 with regard to branch instructions. A branch instruction requires program execution either to continue with the instruction immediately following the branch instruction if a certain condition is met, or branch to a different instruction if the particular condition is not met. Accordingly, the outcome of a branch instruction is not known until the instruction is executed. In a pipelined architecture, a branch instruction (or any instruction for that matter) may not be executed for at least several, and perhaps many, clock cycles after the fetch unit in the processor fetches the branch instruction. In order to keep the pipeline full, which is desirable for efficient operation, the processor includes branch prediction logic that predicts the outcome of a branch instruction before it is actually executed (also referred to as “speculating”). The branch predictor 123 , which receives addresses from the VPC queue 122 , preferably bases its speculation on short and long-term history of prior instruction branches. As such, using branch prediction logic, a processor's fetch unit can speculate the outcome of a branch instruction before it is actually executed. The speculation, however, may or may not turn out to be accurate. That is, the branch predictor logic may guess wrong regarding the direction of program execution following a branch instruction. If the speculation proves to have been accurate, which is determined when the processor executes the branch instruction, then the next instructions to be executed have already been fetched and are working their way through the pipeline.
If, however, the branch speculation performed by the branch predictor 123 turns out to have been the wrong prediction (referred to as “misprediction” or “misspeculation”), many or all of the instructions behind the branch instruction may have to be flushed from the pipeline (i.e., not executed) because of the incorrect fork taken after the branch instruction. Branch predictor 123 uses any suitable branch prediction algorithm, however, that results in correct speculations more often than misspeculations, and the overall performance of the processor is better (even in the face of some misspeculations) than if speculation was turned off.
The instruction translation buffer (“ITB”) 124 couples to the instruction cache 110 and the fetch unit 121 . The ITB 124 comprises a 128-entry, fully-associative instruction-stream translation buffer that is used to store recently used instruction-stream address translations and page protection information. Preferably, each of the entries in the ITB 124 may be 1, 8, 64 or 512 contiguous 8-kilobyte (“KB”) pages or 1, 32, 512, 8192 contiguous 64-kilobyte pages. The allocation scheme used for the ITB 124 is a round-robin scheme, although other schemes can be used as desired.
The predecoder 125 reads an octaword (16 contiguous bytes) from the instruction cache 110 . Each octaword read from instruction cache may contain up to four naturally aligned instructions per cycle. Branch prediction and line prediction bits accompany the four instructions fetched by the predecoder 125 . The branch prediction scheme implemented in branch predictor 123 generally works most efficiently when only one branch instruction is contained among the four fetched instructions. The predecoder 125 predicts the instruction cache line that the branch predictor 123 will generate. The predecoder 125 generates fetch requests for additional instruction cache lines and stores the instruction stream data in the instruction cache.
Referring still to FIGS. 2 a and 2 b , the retire unit 126 fetches instructions in program order, executes them out of order, and then retires (also called “committing” an instruction) them in order. The Ibox 120 logic maintains the architectural state of the processor by retiring an instruction only if all previous instructions have executed without generating exceptions or branch mispredictions. An exception is any event that causes suspension of normal instruction execution. Retiring an instruction commits the processor to any changes that the instruction may have made to the software accessible registers and memory. The processor 100 preferably includes the following three machine code accessible hardware: integer and floating-point registers, memory, internal processor registers. The retire unit 126 of the preferred embodiment can retire instructions at a sustained rate of eight instructions per cycle, and can retire as many as 11 instructions in a single cycle.
The decode and rename registers 127 contains logic that forwards instructions to the integer and floating-point instruction queues 128 , 129 . The decode and rename registers 127 perform preferably the following two functions. First, the decode and rename registers 127 eliminates register write-after-read (“WAR”) and write-after-write (“WAW”) data dependency while preserving true read-after-write (“RAW”) data dependencies. This permits instructions to be dynamically rescheduled. Second, the decode and rename registers 127 permits the processor to speculatively execute instructions before the control flow previous to those instructions is resolved.
The logic in the decode and rename registers 127 preferably translates each instruction's operand register specifiers from the virtual register numbers in the instruction to the physical register numbers that hold the corresponding architecturally-correct values. The logic also renames each instruction destination register specifier from the virtual number in the instruction to a physical register number chosen from a list of free physical registers, and updates the register maps. The decode and rename register logic can process four instructions per cycle. Preferably, the logic in the decode and rename registers 127 does not return the physical register, which holds the old value of an instruction's virtual destination register, to the free list until the instruction has been retired, indicating that the control flow up to that instruction has been resolved.
If a branch misprediction or exception occurs, the register logic backs up the contents of the integer and floating-point rename registers to the state associated with the instruction that triggered the condition, and the fetch unit 121 restarts at the appropriate Virtual Program Counter (“VPC”). Preferably, as noted above, 20 valid fetch slots containing up to 80 instructions can be in flight between the registers 127 and the end of the processor's pipeline, where control flow is finally resolved. The register 127 logic is capable of backing up the contents of the registers to the state associated with any of these 80 instructions in a single cycle. The register logic 127 preferably places instructions into the integer or floating-point issue queues 128 , 129 , from which they are later issued to functional units 130 or 136 for execution.
The integer instruction queue 128 preferably includes capacity for 20 integer instructions. The integer instruction queue 128 issues instructions at a maximum rate of four instructions per cycle. The specific types of instructions processed through queue 128 include: integer operate commands, integer conditional branches, unconditional branches (both displacement and memory formats), integer and floating-point load and store commands, Privileged Architecture Library (“PAL”) reserved instructions, integer-to-floating-point and floating-point-integer conversion commands.
Referring still to FIGS. 2 a and 2 b , the integer execution unit (“Ebox”) 130 includes arithmetic logic units (“ALUs”) 131 , 132 , 133 , and 134 and two integer register files 135 . Ebox 130 preferably comprises a 4-path integer execution unit that is implemented as two functional-unit “clusters” labeled 0 and 1 . Each cluster contains a copy of an 80-entry, physical-register file and two subclusters, named upper (“U”) and lower (“L”). As such, the subclusters 131 – 134 are labeled U 0 , L 0 , U 1 , and L 1 . Bus 137 provides cross-cluster communication for moving integer result values between the clusters.
The subclusters 131 – 134 include various components that are not specifically shown in FIG. 2 a . For example, the subclusters preferably include four 64-bit adders that are used to calculate results for integer add instructions, logic units, barrel shifters and associated byte logic, conditional branch logic, a pipelined multiplier for integer multiply operations, and other components known to those of ordinary skill in the art.
Each entry in the integer instruction queue 128 preferably asserts four request signals—one for each of the Ebox 130 subclusters 131 , 132 , 133 , and 134 . A queue entry asserts a request when it contains an instruction that can be executed by the subcluster, if the instruction's operand register values are available within the subcluster. The integer instruction queue 128 includes two arbiters—one for the upper subclusters 132 and 133 and another arbiter for the lower subclusters 131 and 134 . Each arbiter selects two of the possible 20 requesters for service each cycle. Preferably, the integer instruction queue 128 arbiters choose between simultaneous requesters of a subcluster based on the age of the request—older requests are given priority over newer requests. If a given instruction requests both lower subclusters, and no older instruction requests a lower subcluster, then the arbiter preferably assigns subcluster 131 to the instruction. If a given instruction requests both upper subclusters, and no older instruction requests an upper subcluster, then the arbiter preferably assigns subcluster 133 to the instruction.
The floating-point instruction queue 129 preferably comprises a 15-entry queue and issues the following types of instructions: floating-point operates, floating-point conditional branches, floating-point stores, and floating-point register to integer register transfers. Each queue entry preferably includes three request lines—one for the add pipeline, one for the multiply pipeline, and one for the two store pipelines. The floating-point instruction queue 129 includes three arbiters—one for each of the add, multiply, and store pipelines. The add and multiply arbiters select one requester per cycle, while the store pipeline arbiter selects two requesters per cycle, one for each store pipeline. As with the integer instruction queue 128 arbiters, the floating-point instruction queue arbiters select between simultaneous requesters of a pipeline based on the age of the request—older request are given priority. Preferably, floating-point store instructions and floating-point register to integer register transfer instructions in even numbered queue entries arbitrate for one store port. Floating-point store instructions and floating-point register to integer register transfer instructions in odd numbered queue entries arbitrate for the second store port.
Floating-point store instructions and floating-point register to integer register transfer instructions are queued in both the integer and floating-point queues. These instructions wait in the floating-point queue until their operand register values are available from the floating-point execution unit (“Fbox”) registers. The instructions subsequently request service from the store arbiter. Upon being issued from the floating-point queue 129 , the instructions signal the corresponding entry in the integer queue 128 to request service. Finally, upon being issued from the integer queue 128 , the operation is completed.
The integer registers 135 , 136 preferably contain storage for the processor's integer registers, results written by instructions that have not yet been retired, and other information as desired. The two register files 135 , 136 preferably contain identical values. Each register file preferably includes four read ports and six write ports. The four read ports are used to source operands to each of the two subclusters within a cluster. The six write ports are used to write results generated within the cluster or another cluster and to write results from load instructions.
The floating-point execution queue (“Fbox”) 129 contains a floating-point add, divide and square-root calculation unit 142 , a floating-point multiply unit 144 and a register file 146 . Floating-point add, divide and square root operations are handled by the floating-point add, divide and square root calculation unit 142 while floating-point operations are handled by the multiply unit 144 .
The register file 146 preferably provides storage for 72 entries including 31 floating-point registers and 41 values written by instructions that have not yet been retired. The Fbox register file 146 contains six read ports and four write ports (not specifically shown). Four read ports are used to source operands to the add and multiply pipelines, and two read ports are used to source data for store instructions. Two write ports are used to write results generated by the add and multiply pipelines, and two write ports are used to write results from floating-point load instructions.
Referring still to FIG. 2 a , the Mbox 150 controls the L 1 data cache 160 and ensures architecturally correct behavior for load and store instructions. The Mbox 150 preferably contains a datastream translation buffer (“DTB”) 151 , a load queue (“LQ”) 152 , a store queue (“SQ”) 153 , and a miss address file (“MAF”) 154 . The DTB 151 preferably comprises a filly associative translation buffer that is used to store data stream address translations and page protection information. Each of the entries in the DTB 151 can map 1, 8, 64, or 512 contiguous 8-KB pages. The allocation scheme preferably is round robin, although other suitable schemes could also be used. The DTB 151 also supports an 8-bit Address Space Number (“ASN”) and contains an Address Space Match (“ASM”) bit. The ASN is an optionally implemented register used to reduce the need for invalidation of cached address translations for process-specific addresses when a context switch occurs.
The LQ 152 preferably is a reorder buffer used for load instructions. It contains 32 entries and maintains the state associated with load instructions that have been issued to the Mbox 150 , but for which results have not been delivered to the processor and the instructions retired. The Mbox 150 assigns load instructions to LQ slots based on the order in which they were fetched from the instruction cache 110 , and then places them into the LQ 152 after they are issued by the integer instruction queue 128 . The LQ 152 also helps to ensure correct memory reference behavior for the processor.
The SQ 153 preferably is a reorder buffer and graduation unit for store instructions. It contains 32 entries and maintains the state associated with store instructions that have been issued to the Mbox 150 , but for which data has not been written to the data cache 160 and the instruction retired. The Mbox 150 assigns store instructions to SQ slots based on the order in which they were fetched from the instruction cache 110 and places them into the SQ 153 after they are issued by the instruction cache 110 . The SQ 153 holds data associated with the store instructions issued from the integer instruction unit 128 until they are retired, at which point the store can be allowed to update the data cache 160 . The LQ 152 also helps to ensure correct memory reference behavior for the processor.
The MAF 154 preferably comprises a 16-entry file that holds physical addresses associated with pending instruction cache 110 and data cache 160 fill requests and pending input/output (“I/O”) space read transactions.
Processor 100 preferably includes two on-chip primary-level (“L1”) instruction and data caches 110 and 160 , and single secondary-level, unified instruction/data (“L2”) cache 180 ( FIG. 2 b ). The L 1 instruction cache 110 preferably is a 64-KB virtual-addressed, two-way set-associative cache. Prediction is used to improve the performance of the two-way set-associative cache without slowing the cache access time. Each instruction cache block preferably contains a plurality (preferably 16) instructions, virtual tag bits, an address space number, an address space match bit, a one-bit PALcode bit to indicate physical addressing, a valid bit, data and tag parity bits, four access-check bits, and predecoded information to assist with instruction processing and fetch control.
The L 1 data cache 160 preferably is a 64-KB, two-way set associative, virtually indexed, physically tagged, write-back, read/write allocate cache with 64-byte cache blocks. During each cycle the data cache 160 preferably performs one of the following transactions: two quadword (or shorter) read transactions to arbitrary addresses, two quadword write transactions to the same aligned octaword, two non-overlapping less-than quadword writes to the same aligned quadword, one sequential read and write transaction from and to the same aligned octaword. Preferably, each data cache block contains 64 data bytes and associated quadword ECC bits, physical tag bits, valid, dirty, shared, and modified bits, tag parity bit calculated across the tag, dirty, shared, and modified bits, and one bit to control round-robin set allocation. The data cache 160 is organized to contain two sets, each with 512 rows containing 64-byte blocks per row (i.e., 32 KB of data per set). The processor 100 uses two additional bits of virtual address beyond the bits that specify an 8-KB page in order to specify the data cache row index. A given virtual address might be found in four unique locations in the data cache 160 , depending on the virtual-to-physical translation for those two bits. The processor 100 prevents this aliasing by keeping only one of the four possible translated addresses in the cache at any time.
The L 2 cache 180 preferably is a 1.75-MB, seven-way set associative write-back mixed instruction and data cache. Preferably, the L 2 cache holds physical address data and coherence state bits for each block.
Referring now to FIG. 2 b , the L 2 instruction and data cache control unit (“Cbox”) 170 controls the L 2 instruction and data cache 190 and system ports. As shown, the Cbox 170 contains a fill buffer 171 , a data cache victim buffer 172 , a system victim buffer 173 , a cache miss address file (“CMAF”) 174 , a system victim address file (“SVAF”) 175 , a data victim address file (“DVAF”) 176 , a probe queue (“PRBQ”) 177 , a requester miss-address file (“RMAF”) 178 , a store to I/O space (“STIO”) 179 , an arbitration unit 181 , and set of configuration registers 183 .
The fill buffer 171 preferably in the Cbox is used to buffer data that comes from other functional units outside the Cbox. The data and instructions get written into the fill buffer and other logic units in the Cbox process the data and instructions before sending to another functional unit or the L 1 cache. The data cache victim buffer (“VDF”) 172 preferably stores data flushed from the L 1 cache or sent to the System Victim Data Buffer 173 . The System Victim Data Buffer (“SVDB”) 173 is used to send data flushed from the L 2 cache to other processors in the system and to memory. Cbox Miss-Address File (“CMAF”) 174 preferably holds addresses of L 1 cache misses. CMAF updates and maintains the status of these addresses. The System Victim-Address File (“SVAF”) 175 in the Cbox preferably contains the addresses of all SVDB data entries. Data Victim-Address File (“DVAF”) 176 preferably contains the addresses of all data cache victim buffer (“VDF”) data entries.
The Probe Queue (“PRBQ”) 177 preferably comprises a 18-entry queue that holds pending system port cache probe commands and addresses. This queue includes 10 remote request entries, 8 forward entries, and lookup L 2 tags and requests from the PRBQ content addressable memory (“CAM”) against the RMAF, CMAF and SVAF. Requestor Miss-Address Files (“RMAF”) 178 in the Cbox preferably accepts requests and responds with data or instructions from the L 2 cache. Data accesses from other functional units in the processor, other processors in the computer system or any other devices that might need data out of the L 2 cache are sent to the RMAF for service. The Store Input/Output (“STIO”) 179 preferably transfer data from the local processor to I/O cards in the computer system. Finally, arbitration unit 181 in the Cbox preferably arbitrates between load and store accesses to the same memory location of the L 2 cache and informs other logic blocks in the Cbox and computer system functional units of the conflict.
Referring now to FIG. 8 , configuration registers 183 preferably include a cbox_acc_ctl register 195 , a cbox_lcl_set register 196 , a cbox_gbl_set register 197 and a cbox_rd_well as additional registers (now shown) as desired. Each register 195 – 197 preferably is a 64-bit programmable register. Each bit in the cbox_acc_ctl register 195 represents a unique block of memory. The full 64-bits represent the maximum possible amount of memory at a processor. If the corresponding bit is clear, the block can only be referenced by processors in the local processor set which is defined by the cbox_lcl_set register 196 . If, however, the corresponding bit is set, the blocks can only be referenced by the processors in the global processor set, defined by the cbox_gbl_set register 197 .
Each bit in the cbox_lcl_set register 196 represents one or more (e.g., four) processors. A set bit indicates the corresponding processor(s) are in the local processor set. Each bit in the cbox_gbl_set register 197 also represents one or more processors. A set bit indicates that the corresponding processor(s) are in the global set. A local processor preferably is always in both the local and the global processor set.
Referring still to FIG. 2 b , processor 100 preferably includes dual, integrated RAMbus memory controllers 190 (Zbox0 and Zbox1). Each Zbox 190 controls 4 or 5 channels of information flow with the main memory 102 ( FIG. 1 ). Each Zbox preferably includes a front-end directory in-flight table (“DIFT”) 191 , a middle mapper 192 , and a back end 193 . The front-end DIFT 191 performs a number of functions such as managing the processor's directory-based memory coherency protocol, processing request commands from the Cbox 170 and Rbox 200 , sending forward commands to the Rbox, sending response commands to and receiving packets from the Cbox and Rbox, and tracking up to 32 in-flight transactions. The front-end DIFT 191 also sends directory read and write requests to the Zbox and conditionally updates directory information based on request type, Local Probe Response (“LPR”) status and directory state.
The middle mapper 192 maps the physical address into RAMbus device format by device, bank, row, and column. The middle mapper 192 also maintains an open-page table to track all open pages and to close pages on demand if bank conflicts arise. The mapper 192 also schedules RAMbus transactions such as timer-base request queues. The Zbox back end 193 preferably packetizes the address, control, and data into RAMbus format and provides the electrical interface to the RAMbus devices themselves.
The Rbox 200 provides the interfaces to as many as four other processors and one I/O controller 104 ( FIG. 1 ). The inter-processor interfaces are designated as North (“N”), South (“S”), East (“E”), and West (“W”) and provide two-way communication between adjacent processors.
To solve the congestion problem noted above that might result from a communication channel 102 being terminated, various timers are included in each processor 100 . These timers include timers in the Rbox 200 , timers in the DIFT, timers in the MAF, and write request I/O timers. Not all of these timers need be included, but preferably are for best performance.
The Rbox 200 timers will now be described with respect to FIG. 3 . The Rbox 200 preferably includes network input ports 330 and microprocessor input ports 340 for input of message packets into the Rbox. The network input ports 330 preferably comprise a North input port (“NIP”) 332 , South input port (“SIP”) 334 , West input port (“WIP”) 336 , and East input port (“EIP”) 338 that permits two-way message passing between microprocessors. The microprocessor input ports 340 preferably include Cbox input port 342 , Zbox0 input port 344 , Zbox1 input port 346 , and I/O input port 348 for message packet transfers within the microprocessor's functional units as well as transfers to the I/O controller 104 ( FIG. 1 ). FIG. 3 further shows two local arbiters 320 for each of the input ports 320 , 340 . The input ports are connected to the Rbox output ports through an interconnect and Rbox logic network 325 that connects each input port to each of the output ports shown in FIG. 3 . In the preferred embodiment, each input port connects to a buffer 310 that in turn connects to a pair of local arbiters 320 .
The output ports preferably include network output ports 360 and microprocessor output ports 370 . In the preferred embodiment, the network output ports include North output port “NOP”) 362 , South output port (“SOP”) 364 , West output port (“WOP”) 366 , and East output port (“EOP”) 372 . The microprocessor output ports preferably consist of Local0 output port 374 , Local1 output port 376 , and I/O output port 378 . Each output port preferably connects to a global arbiter 350 .
Each of the local arbiters 320 selects a message packet among the message packets waiting in the associated buffer 310 of the Input port 330 , 340 . The local arbiters thus nominate a pending request from the buffer 310 for processing. The global arbiters 350 select a message packet from message packets nominated by the local arbiters 320 for transmission on an associated output port 360 , 370 . A more complete description of the arbitration process can be found in commonly owned, co-pending application, Ser. No. 09/653,642, entitled, “Priority Rules for Reducing Network Message Routing Latency,” filed on Aug. 31, 2000.
Network input ports 330 preferably are used to transfer message packets between microprocessors in the multiprocessor system 90 . The microprocessor input ports 340 including Cbox input port 342 , Zbox0 input port 344 , and Zbox1 input port 346 preferably are used to transfer message packets within the microprocessor from the Cbox and Zbox to the Rbox. The I/O input port 348 is used to transfer I/O commands and data messages from the processor 100 to I/O devices connected to the system.
Network output ports 360 send packets to other superscalar microprocessors in the distributed shared memory computer system. The Local0 output port 374 and Local1 output port 376 direct message packets either to the Cbox or Zboxes of the microprocessor. I/O output port 378 transmits message packets to I/O devices connected to the superscalar microprocessor. Global arbiters for each output port after receiving nominations from the input port local arbiter prioritizes a message packet based on the particular input port that it originated from as described in greater detail below.
Referring still to FIG. 3 , the Rbox 200 preferably includes a timer 322 associated with each output port 360 , 370 . Each timer preferably couples to an output port and provides a timeout signal 323 to the interconnect and Rbox logic 325 . Generally, each timer 322 is used to monitor the network for congestion that may result from one or more terminated communication channels 102 .
In accordance with a preferred embodiment of the invention, each timer 322 includes a separate timer for various classes of inter-processor messages. An exemplary set of message types include: forward, I/O, request, fanout, fanin, and response messages. These messages are messages that are passed from one processor to another. One or more of the applications incorporated by reference at the beginning of this disclosure discuss and describe the message types. There preferably are hierarchical dependencies between the message types. What actions are caused to occur as a result of these messages is not particularly important to the present invention. What is important, however, is that these messages are routed from one processor to another and, if one or more communication channels 102 are terminated, may cause traffic congestion when messages are unable to pass through the terminated channel.
FIG. 4 shows an exemplary embodiment of the output port timers 322 . As shown, timer 322 preferably includes a separate timer 322 a–f for each of the message classes noted above. Specifically, the timer 322 includes a forward message timer 322 a , an I/O message timer 322 b , a request timer 322 c , a fanout message timer 322 d , a fanin message timer 322 e , and a response message timer 322 f . Each timer 322 a – 322 f preferably is programmable or preset. Further, each timer can be programmed or preset to expire after a different amount of time as compared to the other timers.
Programming the timers 322 a–f is accomplished using various registers in the Rbox's interconnect and Rbox logic 325 . These registers are labeled as Rbox registers 326 in FIG. 3 and shown individually in FIG. 6 . As shown in FIG. 6 , the Rbox registers 326 include an rbox_config register 380 , an rbox_port_error_status register 382 , an rbox_io_port _error_status register 384 , a port_timer 1 _config register 386 , a port_timer 2 _config register 388 , and an rbox_io_t1cfg register 390 . Other registers may be included to control the operation of the Rbox as desired but are not shown for sake of clarity. The config register 380 , the rbox_port_error_status register 382 , the port_timer 1 _config register 386 , and the port_timer 2 _config register 388 are implemented preferably as four separate registers as shown including one register for each of the north, south, east and west ports.
Referring now to FIGS. 3 , 4 , and 6 , the timers 322 for the north, south, east, and west network output ports 360 and the timer for the I/O port 378 can be programmed using the port_timer 1 _config, port_timer 2 _config, and rbox_io_t1cfg registers 386 , 388 and 390 . The port_timer 1 _config registers 386 includes enable bits 6 , 13 , and 20 which are used to individually enable the response timer 322 f , the forward timer 322 a and the request timer 322 c , respectively. The count value for each timer is written into the fields adjacent each enable bit. Bits 0 to 5 are used program the response timer 322 f . Bits 7 to 12 are used to program the forward timer 322 a and bits 14 to 19 are used to program the request timer 322 c . Each bit field preferably includes 6 bits and each corresponds to 1/16 th second increments. Thus, with 6 bits each timer can be programmed in 1/16 th second increments up to 4 seconds.
Programming the other timers in the Rbox 200 follows a similar procedure. Bits 6 , 13 , 20 , and 27 of the port_timer 2 _config register 388 are used to enable or disable the read I/O timer, the write I/O timer (both of which are part of the I/O timer 322 b ), the fanout timer 322 d , and the fanin timer 322 e . The bit fields adjacent each enable bit can be loaded with 6 bit values to program the expiration time of the associated timer as described above. Similarly, the rbox_io 13 t1cfg register 390 includes timer enable bits 6 , 13 , 20 , and 27 for the response timer 322 f , forward timer 322 e , and read and write I/O timers 322 b , respectively, for the I/O output port 378 . The adjacent bit fields are used to load the desired expiration times for the timers.
Referring to FIG. 5 , each of the input port buffers 310 preferably include separate storage for input messages of one or more of the various classes of messages noted above. Accordingly, a buffer 310 may contain a forward message buffer 310 a , an I/O message buffer 310 b , a request message buffer 310 c , a fanout message buffer 310 d , a fanin message buffer 310 e , and a response message buffer 310 f . Not every input buffer 310 shown in FIG. 3 need contain all of buffers 310 a–f . For example, the IO port 348 buffer may only include a forward message buffer 310 a , an I/O message buffer 310 b , and a response message buffer 310 f if desired. Accordingly, the timer 322 associated with I/O output port 378 may only include timers for forward messages (timer 322 a ), I/O messages (I/O timer 322 b ) and response messages (timer 322 f ). Further, each of the buffers 310 a–f may be implemented as multiple buffers as desired. For example the I/O buffer 310 b may be implemented as a write I/O buffer and a separate read I/O buffer. If so implemented I/O timer 322 b may be implemented as a write I/O timer and a read I/O timer.
A buffer 310 may become full of pending transactions if a communication channel 102 in the network has been terminated. If that is the case, the buffer 310 will remain full because the buffered transactions are not permitted to be processed from the buffer due to traffic congestion in the network caused by the terminated communication channel. The timers are used as a way to help detect a traffic congestion problem.
For each class of messages at each output port 360 , 370 of a sending processor 100 , the associated timer 322 preferably increments whenever the input buffer 310 of the message class at the receiving processor is currently being used. The timer 322 will continue counting until it reaches its predetermined expiration value and then will assert the timeout signal 323 . Each timer 322 , however, is reset (e.g., forced to 0 if implemented as a count-up timer) whenever a message of the associated message class is sent out from the output port 360 , 370 in which the timer 322 resides. Additionally, the timer 322 is reset whenever the receiving processor 100 frees up an input buffer 310 entry of the associated message class. To implement this latter condition, after the receiving processor frees up the buffer entry, the receiving processors preferably transmits back to the sending processor a message that indicates that buffer space has been deallocated. Upon receiving this deallocation message, the associated timer 322 is reset.
The timeout values are set so that when the timers expire, the processor 100 containing the expired timer is reasonably assured that the input buffer 310 associated with the expired timer 322 cannot empty presumable due to traffic congestion somewhere in the network. When a timer expires, an associated status bit becomes asserted in one of the Rbox status registers 382 , 384 ( FIG. 6 ). As shown, bits 12 – 18 of the rbox_port_error_status register 382 indicate an expired timer for a response timer 322 f , request timer 322 c , forward timer 322 a , read/write I/O timer 322 b , fanout timer 322 d , and fanin timer 322 e , respectively. Similarly, the rbox_io_error_status register 384 includes four status bits 12 – 15 to indicate an expire response timer, forward timer, and read and write I/O timers. When a timer expires (as detected by an asserted status bit in registers 382 , 384 , the timeout signal 323 is asserted to the interconnect and Rbox logic network 325 which responds in any suitable manner.
When one of the timers 322 a–f associated with a particular output port and message class expires, the interconnect and Rbox logic 325 shuts down that output port thereby precluding messages of the same class from being sent out of the port.
Referring briefly to FIG. 6 , to terminate a north, south, east or west communication port 102 , the rbox_config register 380 is used. Specifically, the input enable (“IE”) bit preferably is cleared to terminate the port. Other features of a port may be disabled as desired to discontinue communications.
Referring again to FIG. 2 b , as shown each Zbox 190 includes a DIFT timer 191 a associated with the front end DIFT 191 . The DIFT timer 191 a performs the function of monitoring the status of forward messages in the DIFT for network congestion. The following explanation of a forward message may be helpful to understand the function performed by the DIFT timer 191 a.
Referring FIGS. 1 and 2 b , processor 100 a may desire to read a block of data for which processor 100 b is the “home” processor. A home processor maintains the coherence directory for one or more, and preferably many, blocks of memory. Accordingly, any other processor in the system that desires to access a block of memory must transmit its request to the particular block's home processor. Processor 100 b receives the request from the requestor processor 100 a . Home processor 100 b examines the directory entry for the requested memory block to determine the state of the block. It may be that another processor in the network has the block exclusive or that other processors have shared copies of the block. An exclusive directory state means the processor having the block exclusive can change the data. Processors that share a block can read the data, but not change it. Of course, the home processor 100 b may have the block in a local state. If, for example, a copy of the requested block has given on an exclusive basis to processor 100 c , home processor 100 b will send a forward message to processor 100 c to indicate to processor 100 c that processor 100 a now would like the block exclusive. As a result, processor 100 c should transmit a copy of the block to processor 100 a and give exclusivity to the block to processor 100 a.
Each Zbox 190 performs the directory look ups to determine if a forward message is necessary. If a forward message is necessary, that message is placed into the front end DIFT 191 to eventually be processed through the Rbox 200 . The front end DIFT 191 contains messages that are being processed through the system. If a communication channel 102 through which the pending DIFT transaction would normally be transmitted has been terminated due to a failure in the system, the pending DIFT forward message may never make its way out of the DIFT 191 because of ensuing traffic congestion.
To detect this type of congestion, the DIFT timer 191 a monitors the status of forward messages in the front end DIFT 191 . The DIFT timer 191 a may include separate timers for each entry in the DIFT 191 . In the preferred embodiment, the DIFT 191 is a 32 entry queue and thus, the DIFT timer 191 a may include 32 separate timers. Alternatively, because it is unlikely all 32 entries in the DIFT 191 will be populated with forward messages at any given point in time, the DIFT timer 191 a may have fewer timers than the number of front end DIFT 191 entries. When a forward message is placed into the front end DIFT 191 , its associated DIFT timer 191 a begins counting. The amount of time (i.e., number of clock cycles) for which the DIFT timer 191 a counts can either be preset or programmable as discussed below.
Referring briefly to FIG. 7 , each Zbox 190 includes a zbox_dift_timeout register 402 . As shown, register 402 includes a DIFT timeout enable bit 31 which enables or disables the DIFT timer 191 a . Bit field 0 to 30 comprises a 31 bit field in which a DIFT timeout value is written. The DIFT timer 191 a preferably preferably is a 5-bit, count down timer that begins decrementing from the timeout value down to 0. The timeout value loaded into bits 0 to 30 specify the period of the clock pulses counted by the DIFT timer. This allows DIFT timer timeouts in the range of 2 6 to 2 36 clock cycles.
When the DIFT timer expires, the Zbox 190 determines that the system 90 is experiencing forward message traffic congestion. In response to an expired DIFT timer 191 a , the Zbox 190 preferably sets the directory state of the block to “incoherent” to indicate an error state. The prior contents of the memory location are preserved. Further, the Zbox frees up the DIFT 191 entry that contained the forward message.
The DIFT timer 191 a preferably is reloaded when it counts down to 0, when the enable bit 31 transitions from the disable state to the enable state (e.g., from logic 0 to 1), or when the system resets.
Other timers can be included in processor 100 to monitor for other effects caused by traffic congestion. For example, timers can be included in or associated with the miss address file (“MAF”) 154 ( FIG. 2 a ) and write I/O (“WRIO”) activity. A MAF timer can track an outstanding MAF entry and free up the MAF entry if the timer expires. A write I/O acknowledge timer can be included to count whenever a write I/O Acknowledge counter (not specifically shown) is at its maximum value preventing subsequent write I/O messages from proceeding or if an MB is waiting for the acknowledge counter to reach zero. Then the write I/O acknowledge timer expires, the acknowledge counter preferably is cleared.
Referring again to the Cbox register set 183 of FIG. 8 , the cbox_rd_reg 198 preferably includes five bits for status information, e.g., bits 0 – 4 as shown. These bits preferably are used to encode whether a MAF timer has expired, whether a WRIO timer has expired, whether an error response was received to an L 2 cache miss, and whether data and/or instruction streams resulted in a defective memory fill. Other bits, either in the cbox_rd_reg 198 or another Cbox register specify the directory state of a corrupted block, which is information useful to determine the extent of a data corruption after an error.
The processor 100 preferably implements a “sweep” mode that permits software to scan directory states searching for incoherent blocks. This mode is enabled by setting a bit in a register in the Cbox (such register not specifically shown). When the processor 100 is in the sweep mode, local references that find the block in a local state will return the block normally. Local references that find the block in a shared state will return the block normally and update the state of the block to local without sending out shared invalidate messages. Finally, local references that find the block in either the exclusive or incoherent states will set an incoherent bit in a Zbox register (not specifically shown) so that software can determine that the block is incoherent and update the block's state to incoherent.
Referring again to FIG. 1 , in accordance with the preferred embodiment of the invention, the timeout values of the various timers 322 , 191 a discussed above can and preferably are set differently for the processor ports that connect processors between two domains. This permits increased flexibility in managing the domains for failure isolation.
Preferably, because of hierarchical dependencies between the message types as noted above, the various timers are programmed or preset in such a way to minimize or eliminate collateral damage resulting from a network failure. One suitable ordering from shortest timeout time to longest time for a semi-hard domain implementation is the following:
1. Router inter-domain responses 2. Router intra-domain responses/router intra-domain fanins 3. Router intra-domain fanouts 4. Router inter-domain forwards 5. DIFT entry timers 6. Router inter-domain requests 7. Router inter-domain I/O and router intra-domain requests 8. Router intra-domain I/O 9. MAF timers 10. IO Acknowledge timers
The above ordering is preferred because it ensures that a timeout of a MAF or DIFT entry or a WRIO acknowledge should only occur because a message truly became lost. Preferably, a response should not be delayed so long that it arrives after the associated MAF or DIFT entry times out.
The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.
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A multi-processor computer system permits various types of partitions to be implemented to contain and isolate hardware failures. The various types of partitions include hard, semi-hard, firm, and soft partitions. Each partition can include one or more processors. Upon detecting a failure associated with a processor, the connection to adjacent processors in the system can be severed, thereby precluding corrupted data from contaminating the rest of the system. If an inter-processor connection is severed, message traffic in the system can become congested as messages become backed up in other processors. Accordingly, each processor includes various timers to monitor for traffic congestion that may be due to a severed connection. Rather than letting the processor continue to wait to be able to transmit its messages, the timers will expire at preprogrammed time periods and the processor will take appropriate action, such as simply dropping queued messages, to keep the system from locking up.
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This application claims Benefit of Provisional Application Ser. No. 60/014,835, filed Apr. 4, 1996.
This invention particularly relates to ball screw and nut assemblies which are useful as linear actuators.
BACKGROUND OF THE INVENTION
Linear ball screw-type actuators are used in many applications to transmit linear motion in performing such operations as opening and closing, raising and lowering, pushing and pulling, advancing and retracting, and positioning various devices. In these devices a screw is typically supported within a relatively telescoping inner and outer tube for rotation by a motor and gear box assembly. A ball nut is mounted on the screw and coupled to the slidable inner tube, converting the rotary motion of the motor and screw to linear motion of the inner tube. The inner tube carries a clevis or other connector at its free end which is coupled to the device to be actuated.
Generally, stop washers or pins are provided on the screw at its opposite ends to halt the travel of the ball nut along the screw, thereby establishing fully extended and retracted inner tube stroke limits. The sudden stoppage of the ball nut as it impacts such stops imparts a jolting shock force to the actuator parts, which can be considerable, particularly when the actuator is under heavy load.
SUMMARY OF THE INVENTION AND ADVANTAGES
The present invention overcomes the foregoing objections by incorporating cushioning mechanism with the actuator that absorbs the energy of impact as the actuator reaches its fully extended and retracted positions, thus greatly reducing or eliminating the jolting forces applied.
One of the prime objects of the invention is to provide a novel method of cushioning the impact of a sudden stop on a payload at either end of an electro-mechanical actuator and collapsing the shock forces imposed, particularly on high speed, high load actuators.
Another object of the cushioning device is to obviate the need for the stop washers or stop pins, which cause the sudden impact forces.
A further object of the invention is to provide a single cushioning device which serves to cushion the travel of the actuator in both the fully retracted and extended positions.
Still another object of the invention is to provide a cushioning device designed to be mounted on the end of the screw for confronting an end wall of the inner tube when fully retracted, and confronting the ball nut when the inner tube is fully extended.
Still another object of the invention is to provide a simple, practical and durable cushioning device that can be readily adapted to present actuator designs without significant modification of their construction.
Another object of the invention is to provide a cushioning device that is self contained and detachable from the actuator to facilitate repair or replacement, when needed.
These and other objects, advantages and features of the present invention will become more readily apparent from the following detailed description when taken together with the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly sectional, elevational view of a typical ball screw actuator fitted with a travel stop cushioning device which is constructed in accordance with a presently preferred embodiment the invention;
FIG. 2 is a partly sectional, exploded view of the components that make up the cushioning device;
FIG. 3 is an enlarged cross-sectional view taken along the lines 3--3 of FIG. 1; and
FIG. 4 and 5 are enlarged fragmentary sectional views showing the actuator in its fully retracted and extended positions, respectively.
DETAILED DESCRIPTION
With reference to FIG. 1 initially, there is illustrated an electro-mechanical linear actuator assembly 10 having an electric motor 12, gearbox 14, and a ball nut and screw mechanism, generally indicated at 16, housed within a fixed outer tube 17 which is secured by nut and bolt fasteners 19 to a base plate 20 of the actuator 10.
The mechanism 16 includes a typical ball screw 22 provided with helical ball-accommodating groove portions 22a separated by helical land portions 22b. Coaxially provided on the screw 22, is a ball nut 24 which has matching internal groove and land portions and is provided with an exterior ball return tube 26 to recirculate a train of abutting load bearing balls B to facilitate linear movement of the ball nut 24 along the ball screw 24 in response to rotation of the screw 22. Such a mechanism is disclosed, for example, in U.S. Pat. No. 5,485,760, which is owned by the assignee of the present invention and its disclosure incorporated herein by reference.
The nut 24, at the time of fabrication, is provided with an integrated cylindrical extension portion, generally designated 28, which is arranged in concentric spaced relation to the screw 22 to define an annular recess 30 therebetween. An inner extension tube 18 is fixed at its inner end to the extension portion 28 of the nut 24 and extends longitudinally therefrom to an opposite free end on which a clevis 32 or other connector may be mounted. The clevis 32 is shown as having an attachment opening 34 for connection to the device to be actuated (not shown) in the conventional manner.
A ball screw mounted travel limit/dampening device constructed in accordance with a presently preferred embodiment of the invention is designated generally at 38 in the drawings and comprises a carrier such as a cylindrical housing, cage, support, or container 38a which is closed at one end by an end wall or activating wall or end part 40 and which is open at its opposite end.
A conventional shock absorber or compressible shock absorbing device, generally designated 42, includes a cylinder 44 in which fluid such as a compressible gas is contained, and a relatively slidable plunger 46, which normally is in the extended FIG. 2 position, has relative movement with the cylinder 44 to displace the fluid and absorb an applied force. The plunger 46 is automatically returned outwardly by the usual compression spring in cylinder 44 (not shown) upon removal of the applied force. A fixed, externally threaded adapter 48 forms a part of and is fixed to the interiorly positioned end of the cylinder 44, as illustrated best in FIG. 2. The shock absorber 42 preferably is a self-contained unit available commercially from Endine Company, model number FP3984. The shock absorber or cushioning device 42 of which many forms are available, is housed within a double acting, cylinder carrying reaction carrier or enclosure 49 which operates in conjunction with the extension tube 18, and nut 24 to limit the travel of the nut extension tube 18 while dampening the sudden stoppage of the nut extension tube 18 at each end of its stroke as will be described in greater detail below.
A shock absorber guide 50 is coupled to adaptor 48 to function as a part thereof and includes a cylindrical body 50a (FIG. 3) having an outer diameter corresponding generally to that of the fluid cylinder 44, opposing inner and outer end faces 50b, 50c, and an internally threaded, axial bore 50d. A guide part comprising a pair of diametrically opposed wings, ears, or reaction arms 52 project radially outwardly of the body 50a, presenting forward 52a and rearward 52b facing abutment surfaces. The guide 50 is preferably fabricated from a hard, wear-resistant material, such as SAE 4340H, 4140, 4190 or 6150 grades of steel, hardened and tempered typically to Rc 38-40.
The shock guide 50 is mounted securely but removably on the end of the shock absorber 42 by threading the externally threaded adapter 48 into the threaded bore 50d of the guide 50, until the inner end face 50b of the guide 50 is brought to bear tightly against the opposing end face 44a of the fluid cylinder 44. Once connected, the shock absorber 42 and guide 50 are inserted as a unit, (plunger 46 first) into the shock absorber carrier or housing 38.
The shock housing 38 is formed with a guide part comprising a pair of first open-ended, diametrically opposed longitudinal guide slots 54 that are arranged and dimensioned to slidably accommodate the ears 52 of the shock guide 50, and which terminate within the housing 38 at closed abutment ends 54a. As most clearly seen in FIG. 3, the ears 52 of the shock guide 50 extend radially outwardly beyond the outer peripheral surface of the shock housing 38. The end wall 40 of the housing 38 is also formed on its interior side with a central recessed seat 56 in which the free end 46a of the plunger 46 is accommodated.
A guide mount for guide 50, generally designated 58, has a generally cylindrical body 60 formed with a flat inner end face 60a and a transverse bore 60b extending diametrally through the body 60. An externally threaded mounting stud 62 projects from an opposite outer end face 60c of the body 60. The body 60 of the guide mount 58 is received in the open end of the shock housing 38, such that the inner end face 60a confronts the outer end face 50c of the shock guide 50. The guide mount 58 is likewise fabricated of a hard, wear-resistant material and preferably the same materials as those used for the shock guide 50, hardened and tempered typically to Rc 38-40.
The guide mount 58 is retained within the housing 38 by means of a hardened, ground dowel pin 64, extending through the opening 60b in the guide mount and having ends 64a thereof projecting outwardly through diametrically opposed second slots 66 formed in the housing 38 (FIG. 3). The structure provides a pin and slot lost motion connection. The slots 66 are preferably 90° offset from the guide slots 54 and extend longitudinally (FIG. 2) between forward 66a and rearward 66b closed marginal slot ends. It should be noted at this time that the relative dimensions of the components are such that the shock absorber 42 must be compressed somewhat during assembly in order to extend the opening 60b of the guide mount 58 sufficiently inward to register it with the rearward ends 66b of the slots 66 to enable insertion of the pin 64 into the opening 60b through one of the slots 66. Once the dowel pin 64 is in place, it is urged by the return force of the shock absorber 42 against the rearward interior ends 66b of the slots 66 so as to retain the components of the device 36 securely but removably in assembled relation as a self-contained unit.
As illustrated in FIG. 1, the free end of the ball screw 22 is formed with a threaded axial bore 67. The stud 62 of the guide mount 58 which essentially functions as a part of screw 22 is threaded into the bore 67 until the end face 60c of the guide mount is brought to bear tightly against the end face 22a of the screw 22, thereby mounting the dampening device 36 securely but removably on the screw 22.
A pair of wear washers 70 (FIG. 5) are arranged within the inner tube 18, resting against the end face of the extension portion 28. They are freely rotatable relative to the portion 28 and to one another. The washers 70 are preferably fabricated of a hard, wear-resistant material such as SAE 4150H or 6150 steel typically hardened and tempered to Rc 55-60. By use of the wear washers 70, the extension portion 28 can be fabricated of a milder, less costly grade of steel.
THE OPERATION
The electric motor 12 activates the ball screw 22 through gearing inside the gear box 14 in known manner, causing the ball screw, and hence the dampening device 36, to rotate. U.S. Pat. No. 5,090,513 illustrates typical gearing and is incorporated herein by reference. The ball nut 24 converts the rotary motion of the screw 22 into linear motion of the inner tube 18 to either extend or retract the inner tube.
FIG. 1 illustrates the inner tube in a position just prior to full retraction where the dampening device 36 comes into play. As the inner tube 18 is moved inwardly, a clevis wall 43 confronts the end wall 40 of the shock housing 38, and continued inward advancement displaces the shock housing 38 inwardly (to the right in FIGS. 1 and 4) relative to the fluid cylinder 44, shock guide 50, and guide mount 58, bringing the ears 52 and dowel pin 64 relatively forwardly in their associated slots 54, 66. It should be noted at this point that the end wall 40 has a preferably convex outer surface 41 which seats in the corresponding concave recess 43 of the clevis 32 to maintain concentricity. The confronting surfaces of the end wall 40 and clevis 32 are hardened to resist wear. It is advantageous to form the concave portion 43 of the clevis 32 as a separate insert 68 (FIG. 4) of the same material and hardness as that of the end wall 40. The insert 68 may be joined by welding or other suitable securing means to the clevis 32, as illustrated best in FIG. 4. The relatively large radius of the concavity not only provides a greater contact surface, it also performs a centering function to maintain concentricity of the parts as the shock forces are collapsing.
The inward displacement of the shock housing 38 forces the plunger 46 further into the cylinder 44, thereby dampening the energy of the impact between the housing 38 and clevis 32. Full cushioned retraction is reached when the base walls 54a of the guide slots 54 bottom out against the forward abutment surfaces 52a of the ears 52, as illustrated in FIG. 4. The cushioning device thus prevents material impact forces from being transmitted to the screw 22 and nut 24.
At the other extreme (FIG. 5), driving the inner tube 18 to full extension causes the extension wall portion 28 of the ball nut 24 to move toward the rearward abutment surfaces 52b of the shock guides ears 52.
As the wear washers 70 confront the rearward abutment surfaces 52b of the shock guide ears 52, the shock guide 50 is driven outwardly by continued advancement of the nut 24 (to the left in FIG. 5) relative to the shock housing 38, which is held against movement by engagement of the dowel pin 64 with the rearward ends 66b of the slotted openings 66 (see FIG. 5). The advancement of the nut wall portion 28 is accommodated by the accommodation of the rearward end of the shock housing 38 in the recess 30 of the extension 28. The shock of the confronting surfaces is fully cushioned as previously by the shock absorber 42 as the normally projecting, gas pressure retained plunger 46 is displaced relative to the cylinder 44. Full, but cushioned, extension is achieved when the forward abutment surfaces 52a of the ears 52 confront the base walls 54a of the guide slots 54.
It is understood that the disclosed embodiment is representative of a presently preferred form of the invention and is intended to be illustrative rather than definitive thereof. Other embodiments which accomplish the same function are contemplated and incorporated herein within the scope of the claims. For example, the invention is not limited to the particular ball screw actuator described nor to the particular screw drive arrangement. Furthermore, while the guide mount 58 is described in the preferred embodiment as being threaded into engagement with the ball screw 22, it will be appreciated that other ways of attaching the dampening device 36 to the screw 22 are contemplated by the invention which include, for example, permanently fixing the guide mount 58 to the screw 22 such as by welding. Moreover, the materials and physical properties of the components described are those presently preferred, but others are contemplated.
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A method and apparatus wherein a travel limit/dampening device is coupled to the end of a screw of a linear ball screw actuator device for limiting the travel of an actuator extension coupled to a nut supported for linear driven displacement in either direction along the screw. The travel limit/dampening device includes a gas shock supported within a double acting reaction device reactive axially between the nut and screw when the extension is fully retracted and extended, respectively, to collapse the shock absorber and thereby dampen the movement of the extension at each end of its stroke.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/360,755 which was filed on Jul. 1, 2010 and is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to compounds, to processes for their preparation, to pharmaceutical compositions containing them and to their use in medicine, in particular their use in the treatment of conditions mediated by the action of ligands for the DP 1 , FP, TP, EP 1 and EP 4 prostaglandin (PG) receptors. The present compounds have the general structure shown below and act at different prostaglandin receptors to thereby provide a general anti-inflammatory response.
[0004] 2. Summary of the Related Art
[0005] The EP 1 receptor is a 7-transmembrane receptor and its natural ligand is the prostaglandin PGE 2 . PGE 2 also has affinity for the other EP receptors (types EP 2 , EP 3 and EP 4 ). The EP 1 receptor is associated with smooth muscle contraction, pain (in particular inflammatory, neuropathic and visceral), inflammation, allergic activities, renal regulation and gastric or enteric mucus secretion.
[0006] Prostaglandin E 2 (PGE 2 ) exerts allodynia through the EP 1 receptor subtype and hyperalgesia through EP 2 and EP 3 receptors in the mouse spinal cord. Furthermore, it has been shown that in the EP 1 knock-out mouse pain-sensitivity responses are reduced by approximately 50%. EP 1 receptor antagonist (ONO-8711) reduces hyperalgesia and allodynia in a rat model of chronic constriction injury and inhibits mechanical hyperalgesia in a rodent model of post-operative pain. The efficacy of EP 1 receptor antagonists in the treatment of visceral pain in a human model of hypersensitivity has been demonstrated. Thus, selective prostaglandin ligands, agonists or antagonists, depending on which prostaglandin E receptor subtype is being considered, have anti-inflammatory, antipyretic and analgesic properties similar to a conventional non-steroidal anti-inflammatory drug, and in addition, inhibit hormone-induced uterine contractions and have anti-cancer effects. These compounds have a diminished ability to induce some of the mechanism-based side effects of NSAIDs which are indiscriminate cyclooxygenase inhibitors. In particular, the compounds have a reduced potential for gastrointestinal toxicity, a reduced potential for renal side effects, a reduced effect on bleeding times and a lessened ability to induce asthma attacks in aspirin-sensitive asthmatic subjects. Moreover, as a result of sparing potentially beneficial prostaglandin pathways, these agents may have enhanced efficacy over NSAIDS and/or COX-2 inhibitors.
[0000] (See Pub. No. US 2005/0065200 for other diseases that may be treated by EP4 receptor antagonists.)
[0007] The TP (also known as TxA 2 ) receptor is a prostanoid receptor subtype stimulated by the endogenous mediator thromboxane. Activation of this receptor results in various physiological actions primarily incurred by its platelet aggregatory and smooth muscle constricting effects, thus opposing those of prostacyclin receptor activation.
[0008] TP receptors have been identified in human kidneys in the glomerulus and extraglomerular vascular tissue. Activation of TP receptors constricts glomerular capillaries and suppresses glomerular filtration rates indicating that TP receptor antagonists could be useful for renal dysfunction in glomerulonephritis, diabetes mellitus and sepsis.
[0009] Activation of TP receptors induces bronchoconstriction, an increase in microvascular permeability, formation of mucosal edema and mucus secretion, which are typical characteristic features of bronchial asthma. TP antagonists have been investigated as potential asthma treatments resulting in, for example, orally active Seratrodast (AA-2414). Ramatroban is another TP receptor antagonist currently undergoing phase III clinical trials as an anti-asthmatic compound.
[0010] Since the DP 1 receptor may trigger an asthmatic response in certain individuals, compounds that have DP 1 antagonist properties may be useful as anti-asthmatic drugs.
[0000] (See Pub. No. 2004/0162323 for the disclosure of other diseases and conditions that may be treated with DP antagonists.)
[0011] Finally, the FP receptor modulates intraocular pressure and mediates smooth muscle contraction of the sphincter muscles in the gastrointestinal tract and the uterus. Thus, antagonists of the FP receptor are useful for treating reproductive disorders. (See U.S. Pat. No. 6,511,999 for other diseases and conditions that may be treated with FP receptor antagonists.)
[0012] As further background for the present invention, see US Published Patent Application 2007/0060596.
BRIEF SUMMARY OF THE INVENTION
[0013] This invention provides compounds, that are 1-[(2-{[(alkyl or aryl)methyl]oxy}halo or haloalkyl substituted-phenyl)alkyl]-5-hydrocarbyl or 5-substituted hydrocarbyl-1H-pyrazole carboxylic acid or alkylenylcarboxylic acid or a hydrocarbyl or substituted hydrocarbyl sulfonamide of said carboxylic acid or said alkylenylcarboxylic acid, provided however, said compound is not a 3-carboxylic acid, a sulfonamide thereof, or a 3-methylenylcarboxylic acid.
[0014] Said alkylenyl may be ethylenyl.
[0015] The following terms are used to define the disclosed invention.
[0016] “Hydrocarbyl” refers to a hydrocarbon radical having only carbon and hydrogen atoms. Preferably, the hydrocarbyl radical has from 1 to 20 carbon atoms, more preferably from 1 to 12 carbon atoms and most preferably from 1 to 7 carbon atoms.
[0017] “Substituted hydrocarbyl” refers to a hydrocarbyl radical wherein one or more, but not all, of the hydrogen and/or the carbon atoms are replaced by a halogen, nitrogen, oxygen, sulfur or phosphorus atom or a radical including a halogen, nitrogen, oxygen, sulfur or phosphorus atom, e.g. fluoro, chloro, cyano, nitro, hydroxyl, phosphate, thiol, etc.
[0018] “Methylenyl” refers to a —CH 2 — linking group.
[0019] “Ethylenyl” refers to a —CH 2 CH 2 — linking group.
[0020] “Alkylenyl” refers to a divalent alkyl linking group.
[0021] “Alkyl” refers to a straight-chain, branched or cyclic saturated aliphatic hydrocarbon. Preferably, the alkyl group has 1 to 12 carbons. More preferably, it is an alkyl of from 4 to 10 carbons, most preferably 4 to 8 carbons. Typical alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl and the like. The alkyl group may be optionally substituted with one or more substituents are selected from the group consisting of hydroxyl, cyano, alkoxy, ═O, ═S, NO 2 , halogen, dimethyl amino, and SH.
[0022] “Cycloalkyl” refers to a cyclic saturated aliphatic hydrocarbon group. Preferably, the cycloalkyl group has 3 to 12 carbons. More preferably, it has from 4 to 7 carbons, most preferably 5 or 6 carbons.
[0023] “Aryl” refers to an aromatic group which has at least one ring having a conjugated pi electron system and includes carbocyclic aryl, heterocyclic aryl and biaryl groups. The aryl group may be optionally substituted with one or more substituents selected from the group consisting of alkyl, hydroxyl, halogen, COOR 6 , NO 2 , CF 3 , N(R 6 ) 2 , CON(R 6 ) 2 , SR 6 , sulfoxy, sulfone, CN and OR 6 , wherein R 6 is alkyl.
[0024] “Carbocyclic aryl” refers to an aryl group wherein the ring atoms are carbon.
[0025] “Heteroaryl” refers to an aryl group having from 1 to 3 heteroatoms as ring atoms, the remainder of the ring atoms being carbon. Heteroatoms include oxygen, sulfur, and nitrogen. Thus, heterocyclic aryl groups include furanyl, thienyl, pyridyl, pyrrolyl, N-lower alkyl pyrrolo, pyrimidyl, pyrazinyl, imidazolyl and the like. Preferably, the heteroaryl group has from 2 to 10 carbons. More preferably, it has from 3 to 10 carbons, most preferably 3 carbons.
[0026] Said 5-hydrocarbyl may be 5-methyl and said (halo or haloalkyl substituted-phenyl)alkyl may be (halo or haloalkyl substituted-phenyl)methyl.
[0027] The compound according to the present invention may be a 1-[(2-{[(alkyl)methyl]oxy}halo or haloalkyl-substituted phenyl)methyl]-5-methyl-1H-pyrazole-3-ethylenylcarboxylic acid, or a 1-[(2-{[(aryl)methyl]oxy}halo or haloalkyl-substituted phenyl)methyl]-5-methyl-1H-pyrazole-3-carboxylic acid fluoro-substituted alkylsulfonamide or alkylenylcarboxylic acid fluoro-substituted alkylsulfonamide wherein said halo is selected from the group consisting of fluoro, chloro and bromo.
[0028] Said halo or haloalkyl-substituted phenyl may be selected from the group consisting of trifluoromethylphenyl, chlorophenyl and bromophenyl.
[0029] Preferably, the compound of the present invention may be a trifluoromethylsulfonamide wherein said aryl is chlorophenyl.
[0030] Most preferably said alkyl comprising said -{[(alkyl)methyl]oxy} is 3-pentyl.or cyclopentyl.
[0031] The invention further relates to pharmaceutical compositions containing the above compounds in combination with a pharmaceutically-acceptable excipient and to their use in medicine, in particular their use in the treatment of conditions mediated by the action of ligands for the DP 1 , FP, EP 1 and EP 4 prostaglandin (PG) receptors. The compounds of this invention are also useful for treating conditions mediated by the action of ligands for the thromboxane (TP) receptor.
[0032] Some embodiments of the present invention include:
[0000] 1. A compound, that is a 1-[(2-{[(alkyl or aryl)methyl]oxy}halo or haloalkyl substituted-phenyl)alkyl]-5-hydrocarbyl or substituted hydrocarbyl-1H-pyrazole carboxylic acid or alkylenylcarboxylic acid or a hydrocarbyl or substituted hydrocarbyl sulfonamide of said carboxylic acid or said alkylenylcarboxylic acid, provided however said compound is not a 3-carboxylic acid, a sulfonamide thereof, or a 3-methylenylcarboxylic acid.
2. A compound according to paragraph 1 wherein said 5-hydrocarbyl is 5-methyl.
3. A compound according to paragraph 2 wherein said halo or haloalkyl substituted-phenylalkyl is halo or haloalkyl substituted-phenyl)methyl.
4. A compound according to paragraph 3, that is a 1-[(2-{[(alkyl)methyl]oxy}halo or haloalkyl-substituted phenyl)methyl]-5-methyl-1H-pyrazole-3-ethylenylcarboxylic acid, wherein said halo is selected from the group consisting of fluoro, chloro and bromo.
5. A compound according to paragraph 3, that is a 1-[(2-{[(aryl)methyl]oxy}halo or haloalkyl-substituted phenyl)methyl]-5-methyl-1H-pyrazole-3-carboxylic acid fluoro-substituted alkylsulfonamide or alkylenylcarboxylic acid fluoro-substituted alkylsulfonamide, wherein said halo is selected from the group consisting of fluoro, chloro and bromo.
6. The compound of paragraph 4 wherein said halo or haloalkyl-substituted phenyl is selected from the group consisting of trifluoromethylphenyl, chlorophenyl and bromophenyl.
7. The compound of paragraph 3 wherein said halo or haloalkyl-substituted phenyl is selected from the group consisting of trifluoromethylphenyl, chlorophenyl and bromophenyl.
8. The compound of paragraph 1 wherein said compound is a trifluoromethylsulfonamide and said aryl is chlorophenyl.
9. The compound of paragraph 6 wherein said alkyl is 3-pentyl.
10. The compound of paragraph 6 wherein said alkyl is cyclopentyl.
11. A compound having the following formula
[0000]
Wherein R 1 is selected from the group consisting of OR 7 , N(R 7 ) 2 , and N(R 7 )SO 2 R 7 wherein R 7 is selected from the group consisting of H, alkyl and aryl, wherein said alkyl and aryl may be substituted with fluoro;
R 2 is selected from the group consisting of H and alkyl;
R 3 is selected from the group consisting of H and alkyl; wherein R 2 and R 3 , individually or together, can form a cycloalkyl ring;
X is (CH 2 ) n wherein n is 0 or an integer of from 1 to 3; provided however that when n is 0 or 1, R 1 is not OR 7 or NR 2 ;
R 4 is selected from the group consisting of H, alkyl and fluoroalkyl;
R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy or aryloxy;
R 6 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy and aryloxy;
Z is (CH 2 ) m wherein m is 0 or an integer of from 1 to 3;
Y is selected from the group consisting of O, S, SO, SO 2 and (CH 2 ) p , wherein p is 0 or an integer of from 1 to 3; and
W is selected from the group consisting of alkyl and aryl.
12. The compound of paragraph 11 wherein R 1 is selected from the group consisting of OH and NHSO 2 CF 3 .
13. The compound of paragraph 12 wherein R 2 and R 3 are H.
14. The compound of paragraph 13 wherein R 4 is alkyl.
15. The compound of paragraph 14 wherein R 4 is methyl.
16. The compound of paragraph 12 wherein R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy, aryloxy and R 6 is H.
17. The compound of paragraph 16 wherein R 5 is selected from the group consisting of H, alkyl, alkoxy, halogen and fluorinated alkyl and alkoxy.
18. The compound of paragraph 17 wherein R 5 is selected from the group consisting of chloro, bromo and trifluoromethyl.
19. The compound of paragraph 12 wherein Z is (CH 2 ).
20. The compound of paragraph 12 wherein Y is O.
21. The compound of paragraph 12 wherein W is selected from the group consisting of alkyl, benzylyl and halogen-substituted benzyl.
22. The compound of paragraph 21 wherein W is selected from the group consisting of alkyls having from 4 to 7 carbon atoms.
23. The compound of paragraph 22 wherein W is cyclopentyl.
24. The compound of paragraph 11, wherein said compound is selected from the group consisting of N-(3-{1-[5-Chloro-2-(4-chloro-benzyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoromethanesulfonamide,
3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid,
3-{1-[5-Bromo-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid,
3-[1-(5-Bromo-2-cyclopentylmethoxybenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid, and
3-[1-(2-Cyclopentylmethoxy-5-trifluoromethylbenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid.
25. A method of making 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid which comprises hydrolyzing a 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid methyl ester, to yield 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid.
26. The method of paragraph 25 wherein said halo is selected from the group consisting of fluoro, chloro and bromo.
27. The method of paragraph 26 wherein said haloalkyl is trifluoromethyl.
28. The method of paragraph 25 wherein said alkyloxy is selected from the group consisting of alkyloxy wherein said alkyl comprises from 4 to 7 carbon atoms.
29. The method of paragraph 28 wherein said alkyl is selected from the group consisting of 3-pentyl and cyclopentylmethyl.
30. The method of paragraph 25 wherein said 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid is prepared by hydrogenating the corresponding (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester to yield 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid.
31. The method of paragraph 30 wherein said hydrogenation is carried out in the presence of a platinum catalyst.
32. The method of paragraph 30 wherein said (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester is prepared by reacting trimethylphosphonoacetate with the corresponding {1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazole-3-carbaldehyde to yield said (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester.
33. A method of making N-(3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoro-methanesulfonamide comprising the step of (a) reacting the corresponding . 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid with cyanuric fluoride to yield 3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl fluoride and (b) reacting said 0.3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl fluoride with trifluoromethanesulfonamide to yield N-(3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoro-methanesulfonamide.
34. The method of paragraph 33 wherein said step (a) is carried out in the presence of pyridine.
35. The method of paragraph 33 wherein said step (b) is carried out in the presence of DMAP.
36. A method comprising administering a compound having the following formula
[0000]
Wherein R 1 is selected from the group consisting of OR 7 , N(R 7 ) 2 , and N(R 7 )SO 2 R 7 wherein R 7 is selected from the group consisting of H, alkyl and aryl, wherein said alkyl and aryl may be substituted with fluoro;
R 2 is selected from the group consisting of H and alkyl;
R 3 is selected from the group consisting of H and alkyl; wherein R 2 and R 3 , individually or together, can form a cycloalkyl ring;
X is (CH 2 ) n wherein n is 0 or an integer of from 1 to 3, provided however that when n is 0 or 1, R 1 is not OR 7 . or NR 2 ;
R 4 is selected from the group consisting of H, alkyl and fluoroalkyl;
R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy or aryloxy;
R 6 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy and aryloxy;
Z is (CH 2 ) m wherein m is 0 or an integer of from 1 to 3;
Y is selected from the group consisting of O, S, SO, SO 2 and (CH 2 ) p , wherein p is 0 or an integer of from 1 to 3; and
W is selected from the group consisting of alkyl and aryl.
37. The method of paragraph 36 wherein said compound is administered to treat DP1, FP, EP1, TP and/or EP4 receptor mediated diseases or conditions.
38. The method of paragraph 37 wherein said condition or disease is related to inflammation.
39. The method of paragraph 37 wherein said DP1, FP, EP1, TP and/or EP4 receptor mediated condition or disease is selected from the group consisting of allergic conditions, asthma, allergic asthma, allergic rhinitis, uveitis and related disorders, atherosclerosis, blood coagulation disorders, bone disorders, cancer, cellular neoplastic transformations, chronic obstructive pulmonary diseases and other forms of lung inflammation, congestive heart failure, diabetic retinopathy, diseases or conditions requiring a treatment of anti-coagulation, diseases requiring control of bone formation and resorption, fertility disorders, gangrene, glaucoma, hyperpyrexia, immune and autoimmune diseases, inflammatory conditions, metastic tumor growth, migraine, mucus secretion disorders, nasal congestion, nasal inflammation, occlusive vascular diseases, ocular hypertension, ocular hypotension, osteoporosis, rheumatoid arthritis, pain, perennial rhinitis, pulmonary congestion, pulmonary hypotension, Raynaud's disease, rejection in organ transplant and by-pass surgery, respiratory conditions, hirsutism, rhinorrhea, shock, sleep disorders, and sleep-wake cycle disorders.
40. The method of paragraph 37 wherein said compound is administered as a surgical adjunct in ophthalmology for cataract removal and artificial lens insertion, ocular implant procedures, photorefractive radial keratotomy and other ophthalmogical laser procedures.
41. The method of paragraph 37 wherein said compound is administered as a surgical adjunct in a procedure involving skin incisions, relief of pain and inflammation and scar formation/keloids post-surgery, for treating sports injuries and general aches and pains in muscles and joints.
42. The method of paragraph 37 wherein said DP 1 , FP, EP 1 , TP, and/or EP 4 receptor mediated condition or disease is an EP 1 and/or EP 4 receptor mediated condition or disease.
43. The method of paragraph 42 wherein said DP 1 , FP, EP 1 , TP and/or EP 4 receptor mediated condition or disease is an allergic condition.
44. The method of paragraph 37 wherein said condition is dermatological allergy.
45. The method of paragraph 37 wherein said condition is an ocular allergy.
46. The method of paragraph 37 wherein said condition is a respiratory allergy.
47. The method of paragraph 37 wherein said condition or disease is selected from the group consisting of nasal congestion, rhinitis, and asthma.
48. The method of paragraph 37 wherein said condition or disease is related to pain.
49. The method of paragraph 37 wherein said condition or disease is selected from the group consisting of arthritis, migraine, and headache.
50. The method of paragraph 37 wherein said condition or disease is associated with the gastrointestinal tract.
51. The method of paragraph 37 wherein said condition or disease is selected from the group consisting of peptic ulcer, heartburn, reflux esophagitis, erosive esophagitis, non-ulcer dyspepsia, infection by Helicobacter pylori , alrynitis, and irritable bowel syndrome.
52. The method of paragraph 37 wherein said condition or disease is selected from the group consisting of hyperalgesia and allodynia.
53. The method of paragraph 37 wherein said condition or disease is related to mucus secretion.
54. The method of paragraph 37 wherein said mucus secretion is gastrointestinal.
55. The method of paragraph 37 wherein said mucus secretion occurs in the nose, sinuses, throat, or lungs.
56. The method of paragraph 37 wherein said condition or disease is related to abdominal cramping.
57. The method of paragraph 37 wherein said condition or disease is irritable bowel syndrome.
58. The method of paragraph 37 wherein said condition or disease is a bleeding disorder.
59. The method of paragraph 37 wherein said condition or disease is a sleep disorder.
60. The method of paragraph 37 wherein said condition or disease is mastocytosis.
61. The method of paragraph 37 wherein said condition or disease is associated with elevated body temperature.
62. The method of paragraph 37 wherein said condition or disease is associated with ocular hypertension and glaucoma.
63. The method of paragraph 37 wherein said condition or disease is associated with ocular hypotension.
64. The method of paragraph 37 wherein said condition relates to surgical produres to treat pain, inflammation and other unwanted sequelae wherein said surgicalprocedure includes incision, laser surgery or implantation.
65. The method of paragraph 37 where said condition is related to pain and inflammation and post-surgical scar and keloid formation.
66. A pharmaceutical product comprising a compound having the following formula
[0000]
Wherein R 1 is selected from the group consisting of OR 7 , N(R 7 ) 2 , and N(R 7 )SO 2 R 7 wherein R 7 is selected from the group consisting of H, alkyl and aryl, wherein said alkyl and aryl may be substituted with fluoro;
R 2 is selected from the group consisting of H and alkyl;
R 3 is selected from the group consisting of H and alkyl; wherein R 2 and R 3 , individually or together, can form a cycloalkyl ring;
X is (CH 2 ) n wherein n is 0 or an integer of from 1 to 3; provided however that when n is 0 or 1, R 1 is not OR 7 . or NR 2 ;
R 4 is selected from the group consisting of H, alkyl and fluoroalkyl;
R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy or aryloxy;
R 6 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy and aryloxy;
Z is (CH 2 ) m wherein m is 0 or an integer of from 1 to 3;
Y is selected from the group consisting of O, S, SO, SO 2 and (CH 2 ) p , wherein p is 0 or an integer of from 1 to 3; and,
W is selected from the group consisting of alkyl and aryl
or a pharmaceutically acceptable salt or a prodrug thereof, wherein said product is packaged and labeled for the treatment or prevention of a disease or condition selected from the group consisting of uveitis, allergic conditions, asthma, allergic asthma, allergic rhinitis, atherosclerosis, blood coagulation disorders, bone disorders, cancer, cellular neoplastic transformations, chronic obstructive pulmonary diseases and other forms of lung inflammation, congestive heart failure, diabetic retinopathy, diseases or conditions requiring a treatment of anti-coagulation, diseases requiring control of bone formation and resorption, fertility disorders, hyperpyrexia, gangrene, glaucoma, hypothermia, immune and autoimmune diseases, inflammatory conditions, metastic tumor growth, migraine, mucus secretion disorders, nasal congestion, nasal inflammation, occlusive vascular diseases, ocular hypertension, ocular hypotension, osteoporosis, pain, perennial rhinitis, pulmonary congestion, pulmonary hypotension, Raynaud's disease, rejection in organ transplant and by-pass surgery, respiratory conditions, rheumatoid arthritis, rhinorrhea, shock, sleep disorders, sleep-wake cycle disorders, sports injuries, muscle aches and pains, and surgical adjunct for minimizing pain, inflammation and scar/keloid formation.
67. A pharmaceutical composition comprising a compound having the following formula
[0000]
Wherein R 1 is selected from the group consisting of OR 7 , N(R 7 ) 2 , and N(R 7 )SO 2 R 7 wherein R 7 is selected from the group consisting of H, alkyl and aryl, wherein said alkyl and aryl may be substituted with fluoro;
R 2 is selected from the group consisting of H and alkyl;
R 3 is selected from the group consisting of H and alkyl; wherein R 2 and R 3 , individually or together, can form a cycloalkyl ring;
X is (CH 2 ) n wherein n is 0 or an integer of from 1 to 3; provided however that when n is 0 or 1, R 1 is not OR 7 . or NR 2 ;
R 4 is selected from the group consisting of H, alkyl and fluoroalkyl;
R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy or aryloxy;
R 6 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy and aryloxy;
Z is (CH 2 ) m wherein m is 0 or an integer of from 1 to 3;
Y is selected from the group consisting of O, S, SO, SO 2 and (CH 2 ) p , wherein p is 0 or an integer of from 1 to 3; and
W is selected from the group consisting of alkyl and aryl
or a pharmaceutically acceptable salt or a prodrug thereof, and a pharmaceutically acceptable excipient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0077] FIGS. 1 and 1 a show the reaction scheme for the preparation of the compounds of this invention, wherein R is R5 and/or R6 and R2 is Z-W in the following description of the present invention;
[0078] FIG. 2 shows modulating the secretion of IL-8 from human macrophages stimulated by TNFα (n=three donors, normalized by cell viability);
[0079] FIG. 3 shows modulating the secretion of MCP-1 from human macrophages stimulated by TNFα (n=three donors, normalized by cell viability);
[0080] FIG. 4 shows modulating the secretion of TNFα from human macrophages stimulated by LPS (n=three donors, normalized by cell viability);
[0081] FIG. 5 shows modulating MDC secretion from human macrophages stimulated by TNFα (n=three donors, normalized by cell viability);
[0082] FIG. 6 shows modulating RANTES secretion from human macrophages stimulated by LPS (n=three donors, normalized by cell viability);
[0083] FIG. 7 shows modulating MDC secretion from human macrophages stimulated by LPS (n=three donors, normalized by cell viability);
[0084] FIG. 8 shows modulating MIP-1 β secretion from human macrophages stimulated by TNFα (n=three donors, normalized by cell viability);
[0085] FIG. 9 shows modulating RANTES secretion from human macrophages stimulated by TNFα (n=three donors, normalized by cell viability);
[0086] FIG. 10 shows the effect of certain compounds of the invention on allergic conjunctival itch;
[0087] FIG. 11 shows the effect of certain compounds of the invention on allergic conjunctival itch; and,
[0088] FIG. 12 shows that certain compounds of the invention have a dose dependent effect when tested in a model for uveitis.
DETAILED DESCRIPTION OF THE INVENTION
[0089] The present invention provides compounds having the general formula:
[0000]
Wherein R 1 is selected from the group consisting of OR 7 , N(R 7 ) 2 , and N(R 7 )SO 2 R 7 wherein R 7 is selected from the group consisting of H, alkyl and aryl, wherein said alkyl and aryl may be substituted with fluoro or fluoroalkyl;
R 2 is selected from the group consisting of H and alkyl;
R 3 is selected from the group consisting of H and alkyl; wherein R 2 and R 3 , individually or together, can form a cycloalkyl ring;
X is (CH 2 ) n wherein n is 0 or an integer of from 1 to 3; provided however that when n is 0 or 1, R 1 is not OR 7 . or NR 2 ;
R 4 is selected from the group consisting of H, alkyl and fluoroalkyl;
R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy or aryloxy;
R 6 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy and aryloxy;
Z is (CH 2 ) m wherein m is 0 or an integer of from 1 to 3;
Y is selected from the group consisting of O, S, SO, SO 2 and (CH 2 ) p , wherein p is 0 or an integer of from 1 to 3;
W is selected from the group consisting of alkyl and aryl;
Preferably, R 1 is selected from the group consisting of OH and NHSO 2 CF 3 ;
Preferably, R 2 is H;
Preferably, R 3 is H;
Preferably, R 4 is alkyl;
More preferably R 4 is methyl;
Preferably, R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy, aryloxy;
More preferably R 5 is selected from the group consisting of H, alkyl, alkoxy, halogen and fluorinated alkyl and fluorinated alkoxy;
Most preferably, R 5 is selected from the group consisting of chloro, bromo and trifluoromethyl;
Preferably, Y is (CH 2 );
Preferably, Z is O;
Preferably, W is selected from the group consisting of isoalkyl, cycloalkyl, phenyl and halogen-substituted phenyl;
More preferably, W is selected from the group consisting of isoalkyl having from 3 to 6 carbon atoms, cyclobutyl, cyclopentyl and cyclohexyl;
Most preferably, W is cyclopentyl or 3-pentyl;
The most preferred compounds of the present invention are selected from the group consisting of N-(3-{1-[5-Chloro-2-(4-chloro-benzyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoromethanesulfonamide,
3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid,
3-{1-[5-Bromo-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid,
3-[1-(5-Bromo-2-cyclopentylmethoxybenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid, and,
3-[1-(2-Cyclopentylmethoxy-5-trifluoromethylbenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid.
[0118] Certain of the compounds of the present invention may be prepared according to methods for preparing similar compounds as set forth in published US Patent Application 2007/0060596 which is hereby incorporated by reference. As shown in FIG. 1 preferably, certain of the preferred compounds of the present invention are prepared by reacting a {1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazole-3-carbaldehyde with trimethylphosphonoacetate to yield an (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester as shown in FIG. 1 . Preferably, said halo is selected from the group consisting of fluoro, chloro and bromo. More preferably said haloalkyl is trifluoromethyl.
[0119] Preferably, said alkyloxy is selected from the group consisting of alkyloxy radicals wherein said alkyl is a branched chain alkyl or cycloalkyl; more preferably said alkyl is selected from the group consisting of branched chain alkyl having from 4 to 7 carbon atoms and cycloalkylmethyl wherein said cycloalkyl is cyclobutyl, cyclopentyl or cyclohexyl and most preferably said alkyl is 3-pentyl or cyclopentylmethyl.
[0120] The (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester is hydrogenated to yield the corresponding 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid.
[0121] Preferably, said hydrogenation is carried out in the presence of a platinum catalyst.
[0122] The 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid methyl ester is hydrolyzed to yield 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid.
[0123] The 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid may be converted to the corresponding N-(3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoro-methanesulfonamide by reacting the 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid with cyanuric fluoride in the presence of pyridine to yield 3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl fluoride and subsequently reacting said 3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl fluoride with trifluoromethanesulfonamide in the presence of DMAP to yield N-(3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoro-methanesulfonamide.
[0124] The following examples are intended to illustrate the present invention.
[0125] The reagents and conditions used in FIG. 1 and the Examples may be abbreviated as follows:
Ac is acetyl; DCM is dichloromethane; TFA is trifluoroacetic acid; RT is room temperature; Ph is phenyl; DiBAL-His diisobutylaluminumhydride; DMF is dimethylformamide; Et is ethyl; THF is tetrahydrofuran; DMAP is 4-dimethylaminopyridine; HEPES is 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid).
Example 1
N-(3-{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Propionyl)-C,C,C-Trifluoromethanesulfonamide, 10
[0137]
Step 1
N′-(5-Chloro-2-Hydroxy-Benzyl)-Hydrazinecarboxylic Acid Tert-Butyl Ester 1
[0138]
[0139] A solution of 5-chloro-2-hydroxybenzaldehyde (1.5 g, 9.3 mmol), tert-butylcarbazate (1.25 g, 9.3 mmol) and acetic acid (0.54 mL, 9.3 mmol) in CH 2 Cl 2 (50 mL) was stirred under a N 2 atmosphere for 30 min at RT. Then sodium triacetoxyborohydride (6.20 g, 27.9 mmol) was added portion wise and the resulting mixture was stirred at RT overnight. The reaction was thoroughly quenched with 2 M HCl (15 mL) and stirred at RT for 1 h. The reaction mixture was partitioned between water (50 mL) and CH 2 Cl 2 (25 mL). The aqueous layer was extracted with CH 2 Cl 2 (25 mL). The combined organic layers were washed with water (2×75 mL), dried (Na 2 SO 4 ) and evaporated to dryness to give hydrazine 1 as a white solid, 2.6 g (100%).
Step 2
1-(5-Chloro-2-Hydroxy-Benzyl)-5-Methyl-1H-Pyrazole-3-Carboxylic Acid Ethyl Ester 2
[0140]
[0141] A suspension of N′-(5-Chloro-2-hydroxy-benzyl)-hydrazinecarboxylic acid tert-butyl ester 1 (9.3 mmol) in CH 2 Cl 2 was treated with TFA (20 mL) and stirred at RT overnight. The volatiles were removed in vacuo. The residue was dissolved in AcOH (20 mL) and slowly added to a solution of ethyl-2,4-dioxopentanoate in AcOH (10 mL). The resulting mixture was refluxed for 1 h, allowed to cool and stirred at RT for 16 h. Precipitated 1-(5-Chloro-2-hydroxy-benzyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester 2 was filtered and washed with ether. The white solid was dried overnight in a dessicator yielding 1.2 g (45%).
Step 3
1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazole-3-Carboxylic Acid Ethyl Ester 3
[0142]
[0143] To a solution of 145-Chloro-2-hydroxy-benzyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester 2 (0.6 g, 2.0 mmol) in DMF (5 mL) were added potassium carbonate (0.84 g, 6.1 mmol), potassium iodide (0.34 g, 2.0 mmol) and 4-chlorobenzylbromide (0.38 g, 2.2 mmol). The resulting mixture was heated at 100° C. overnight. The mixture was poured into water (20 mL) and extracted with Et 2 O (3×15 mL). The organic layers were combined, washed with brine (30 mL), dried (Na 2 SO 4 ) and the volatiles were removed in vacuo to give 0.56 g (71%) of 1-(2-Benzyloxy-5-chloro-benzyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester 3 as a white solid.
Step 4
{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Methanol, 4
[0144]
[0145] To a solution of ester 3 (0.3 g, 0.72 mmol) in THF (6 mL) under N 2 atmosphere was added 1M LiAlH 4 in Et 2 O (2.2 mL, 2.20 mmol). The resulting mixture was stirred at RT for 2 h. 2 M NaOH (2 mL) was added dropwise and the precipitate was removed by filtration. The volatiles were removed in vacuo. The residue was dissolved in EtOAc (20 mL), washed with water (2×15 mL), brine (15 mL), dried (Na 2 SO 4 ) and evaporated to dryness to give alcohol 4 as a white solid, 0.16 g (60%).
Step 5
{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazole-3-Carbaldehyde, 5
[0146]
[0147] A solution of alcohol 4 (0.57 g, 1.3 mmol) and 0.5 M Dess-Martin periodinane (9.05 mL, 4.1 mmol) in CH 2 Cl 2 (25 mL) was stirred under N 2 atmosphere at RT for 3 h. The reaction mixture was quenched with a 10% aqueous solution of Na 2 S 2 O 3 (10 mL) and extracted with more CH 2 Cl 2 (10 mL). The organic layer was washed with water (10 mL), dried (Na 2 SO 4 ) and the volatiles were removed in vacuo. The residue was purified by MPLC (5 g SiO 2 cartridge, eluent 70% iso-hexane-30% CH 2 Cl 2 ) to give aldehyde 5 0.3 g (64%).
Step 6
(E)-3-{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Acrylic Acid Methyl Ester, 6
[0148]
[0149] A solution of aldehyde 5 (0.25 g, 0.65 mmol), LiCl (0.03 g, 1.21 mmol), trimethylphosphonoacetate (0.11 mL, 0.71 mmol) and DBU (0.19 mL, 1.21 mmol) in CH 3 CN (10 mL) was stirred under a N 2 atmosphere at RT for 2 h. The reaction mixture was partitioned between 2 M HCl (15 mL) and EtOAc (20 mL). The organic layer was separated, washed with sat. NaHCO3 (15 mL), brine (15 mL), dried (Na 2 SO 4 ) and the volatiles were removed in vacuo to give a crude ester 6, 0.31 g (99%).
Step 7
3-{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Propionic Acid Methyl Ester, 7
[0150]
[0151] A suspension of unsaturated ester 6 (0.31 g, 0.65 mmol) and 5% Pt/C (0.01 g) in THF (6 mL) and MeOH (12 mL), previously purged with nitrogen, was stirred under a hydrogen atmosphere (balloon) at RT overnight. The platinum was removed by filtration through Hyflo and the filtrate was evaporated to dryness to afford the saturated ester 7, 0.31 g (99%).
Step 8
3-{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Propionic Acid 8
[0152]
[0153] To a solution of ester 7 (0.31 g, 0.65 mmol) in THF (5 mL) was added a solution of LiOH (0.06 g, 1.40 mmol) in water (2 mL) and the resulting mixture was stirred at RT overnight. The volatiles were removed in vacuo. The residue was diluted with water (5 mL) and acidified to pH 1 with 2 M HCl. The acid 8 was isolated by filtration as a white solid and washed with water and dried overnight over KOH in a dessicator to yield 0.09 g (34%).
Step 9
3-{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Propionyl Fluoride 9
[0154]
[0155] To a solution of acid 8 (0.19 g, 0.46 mmol) in dry THF under a N 2 atm was added 60 μL of pyridine and 300 μL (3.4 mmol) of cyanuric fluoride. The mixture was refluxed for 2 hours, cooled to room temperature, diluted with EtOAc and washed with water and brine. After drying over MgSO 4 , solvents were removed in vacuo to yield 0.14 g (72%) of crude acid fluoride. The crude acid fluoride was used in the next step without further purification
Step 10
N-(3-{1-[5-Chloro-2-(4-Chloro-Benzyloxy)-Benzyl]-5-Methyl-1H-Pyrazol-3-yl}-Propionyl)-C,C,C-Trifluoro-Methanesulfonamide, 10
[0156]
[0157] To a solution of acid fluoride 9 (0.14 g, 0.33 mmol) and DMAP 0.161 g (1.3 mmol) in dry DCM, trifluoromethanesulfonamide 0.147 g (0.98 mmol) was added. The mixture was stirred under a nitrogen atmosphere for 16 hours before diluting with EtOAc. The organic phase was washed with 2M HCl, followed by brine, dried over MgSO 4 and evaporated to dryness. The crude acyl sulphonamide 10 was purified on silica to yield 0.13 g as a white solid (72%).
Example 2
3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid, 17
Step 1
[0158]
1-(2-Benzyloxy-5-chloro-benzyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester, 11
[0159]
[0160] The title compound was prepared following the method in Example 1, Step 3 but substituting 4-chlorobenzyl bromide with benzyl bromide.
Step 2
[1-(2-Benzyloxy-5-chloro-benzyl)-5-methyl-1H-pyrazol-3-yl]-methanol, 12
[0161]
[0162] The title compound was prepared following the method in Example 1, Step 4.
Step 3
1-(2-Benzyloxy-5-chloro-benzyl)-5-methyl-1H-pyrazole-3-carbaldehyde, 13
[0163]
[0164] The title compound was prepared following the method in Example 1, Step 5.
Step 4
(E)-3-[1-(2-Benzyloxy-5-chloro-benzyl)-5-methyl-1H-pyrazol-3-yl]-acrylic acid methyl ester, 14
[0165]
[0166] To a stirred solution of aldehyde 13, (1 g, 2.9 mmol) in THF was added (methoxycarbonylmethylene)triphenylphosphorane, 2 g (6 mmol). The mixture was stirred at room temperature for 70 hours. The mixture was diluted with EtOAc and the organic phase was washed with 2M HCl, saturated NaHCO 3 and brine, dried over MgSO 4 and evaporated in vacuo. The crude unsaturated ester 14 was purified on silica to yield 1.2 g as a white solid (99%).
Step 5
3-[1-(5-Chloro-2-hydroxy-benzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid methyl ester, 15
[0167] A stirred solution of unsaturated ester 14, (1.2 g, 2.9 mmol) and PtO 2 , 0.12 g in acetic acid (25 mL) and conc. HCl (5 mL) was hydrogenated at room temperature for 16 hours. The catalyst was removed by filtration through Hyflo and the filtrate was evaporated to dryness to afford the saturated ester 15, 0.8 g (90%).
Step 6
3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid methyl ester 16
[0168]
[0169] To a solution of 3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid methyl ester 15 (0.2 g, 0.63 mmol) in DMF (5 mL) were added potassium carbonate 0.15 g (1.26 mmol), tetrabutylammonium iodide 0.03 g and 3-chloromethylpentane 0.15 g (1.26 mmol). The resulting mixture was heated at 150° C. in a microwave reactor. The mixture was poured into water and extracted with EtOAc. The organic layers were combined, washed with brine (30 mL), dried (MgSO 4 ) and the volatiles were removed in vacuo to give 0.21 g (84%) of the methyl ester 16 as a white solid.
Step 7
3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid, 17
[0170]
[0171] The title compound was prepared following the method in Example 1, Step 8.
Example 3
3-{1-[5-Bromo-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid, 18
[0172]
[0173] The title compound was prepared following the methods described in example 1 and example 2 but starting initially (example 1 step 1) with 5-bromo-2-hydroxybenzaldehyde.
Example 3(a)
[0174] 3-{1-[5-Chloro-2-(2-ethyl-butoxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid, is prepared in a similar manner starting initially with 5-chloro-2-hydroxybenzaldehyde.
Example 4
3-[1-(5-Bromo-2-cyclopentylmethoxybenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid 19
[0175]
[0176] The title compound was prepared following the methods described in example 1 and example 2 but starting initially (example 1 step 1) with 5-bromo-2-hydroxybenzaldehyde and replacing 3-chloromethylpentane in example 2 step 6 with chloromethylcyclopentane.
Example 4(a)
[0177] 3-[1-(5-Chloro-2-cyclopentylmethoxybenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid is also prepared following the methods described in example 1 and example 2 but starting initially (example 1 step 1) with 5-chloro-2-hydroxybenzaldehyde and replacing 3-chloromethylpentane in example 2 step 6 with chloromethylcyclopentane.
Example 5
3-[1-(2-Cyclopentylmethoxy-5-trifluoromethylbenzyl)-5-methyl-1H-pyrazol-3-yl]-propionic acid, 19
[0178]
[0179] The title compound was prepared following the methods described in example 1 and example 2 but starting initially (example 1 step 1) with 5-trifluoromethyl-2-hydroxybenzaldehyde and replacing 3-chloromethylpentane in example 2 step 6 with chloromethylcyclopentane.
[0180] The present invention provides a method of making 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid which comprises hydrolyzing a 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid methyl ester, to yield 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid, wherein said halo is selected from the group consisting of fluoro, chloro and bromo, e.g. said haloalkyl may be trifluoromethyl.
[0181] Preferably, said alkyloxy may be selected from the group consisting of alkyloxy wherein said alkyl comprises from 4 to 7 carbon atoms
[0182] Preferably, said alkyl may be selected from the group consisting of 3-pentyl and cyclopentylmethyl.
[0183] Said 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid may be prepared by hydrogenating the corresponding (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester to yield 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid, e.g. said hydrogenation may be carried out in the presence of a platinum catalyst.
[0184] Said (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester may be prepared by reacting trimethylphosphonoacetate with the corresponding {1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazole-3-carbaldehyde to yield said (E)-3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-acrylic acid methyl ester.
[0185] As can be understood from the above examples, the present invention also provides a method of making N-(3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoro-methanesulfonamide comprising the step of (a) reacting the corresponding. 3-{1-[5-Halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionic acid with cyanuric fluoride to yield 3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl fluoride and (b) reacting said 0.3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl fluoride with trifluoromethanesulfonamide to yield N-(3-{1-[5-halo or haloalkyl-2-(4-chloro-benzyloxy or 4-chloro-alkyloxy)-benzyl]-5-methyl-1H-pyrazol-3-yl}-propionyl)-C,C,C-trifluoro-methanesulfonamide.
[0186] Preferably, said step (a) is carried out in the presence of pyridine and said step (b) is carried out in the presence of DMAP.
[0187] The above compounds were tested for PG antagonist activity as follows using human recombinant prostanoid receptor (DP 1 , EP 1-4 , FP, IP and TP) stable cell lines:
[0188] In order to measure the response of G s and G i coupled prostanoid receptors as a Ca 2+ signal, chimeric G protein cDNAs were used. Stable cell lines over-expressing human prostanoid DP 1 , EP 1-4 , FP, IP, and TP receptors were established as follows:
[0189] Briefly, human prostanoid DP 1 , EP 2 , and EP 4 receptor cDNAs were co-transfected with chimeric G qs cDNA containing a haemagglutanin (HA) epitope; human prostanoid EP 3 receptors were co-transfected with chimeric G qi -HA; human EP 1 , FP, IP, and TP receptor cDNAs were expressed with no exogenous G-proteins. G qs and G qi chimeric cDNAs (Molecular Devices, Sunnyvale, Calif., U.S.A.), as well as cDNAs of prostanoid receptors, were cloned into a pCEP 4 vector with a hygromycin B selection marker. Transfection into HEK-293 EBNA (Epstein-Barr virus nuclear antigen) cells was achieved by the FuGENE 6 transfection Reagent (Roche Applied Science, Indianapolis, Ind., USA). Stable transfectants were selected according to hygromycin resistance. Because G qs and G qi contained an HA epitope, G-protein expression was detected by Western blotting analysis using anti-mouse HA monoclonal antibody and horseradish peroxidase (HRP)-conjugated secondary antibody, while functional expression of prostanoid receptors was detected by FLIPR screening (Matias et al., 2004). These stable cell lines were validated using previously published antagonists at 10 μM against serial dilutions of standard agonists by FLIPR functional assays for Ca 2+ Signaling (as described below).
[0190] Ca 2+ signaling studies were performed using a FLIPR TETRA system (Molecular Devices, Sunnyvale, Calif., USA) in the 384-format. This is a high-throughput instrument for cell-based assays to monitor Ca 2+ signaling associated with GPCRs and ion channels. Cells were seeded at a density of 5×10 4 cells/well in BioCoat poly-D-lysine coated, black wall, clear bottom 384-well plates (BD Biosciences, Franklin lakes, NJ, USA) and allowed to attach overnight in an incubator at 37° C. The cells were then washed twice with HBSS-HEPES buffer (Hanks' balanced salt solution without bicarbonate and phenol red, 20 mM HEPES, pH 7.4) using an ELx405 Select CW Microplate Washer (BioTek, Winooski, Vt., USA). After 60 min of dye-loading in the dark using the Ca 2+ -sensitive dye Fluo-4AM (Invitrogen, Carlsbad, Calif., USA), at a final concentration of 2×10 −6 M, the plates were washed 4 times with HBSS-HEPES buffer to remove excess dye and leaving 50 μl of buffer in each well. The plates were then placed in the FLIPR TETRA instrument and allowed to equilibrate at 37° C. AGN-211377 was added in a 25 μl volume to each well to give final concentrations of 0.1 μM, 0.3 μM, 1 μM, 3 μM, 10 μM, and 30 μM; or 0.067 μM, 0.1 μM, 0.2 μM, 0.3 μM, 0.67 μM, and 1 μM for cells over-expressing TP receptors. After 4.5 minutes, a 7-point serial dilution of the standard agonist for the corresponding receptor, in a 25 μl volume was injected at the final concentrations from 10 −11 M to 10 −5 M in 10-fold serial dilution increments for cells expressing human recombinant DP 1 , EP 1 , EP 2 , EP 3 , EP 4 , FP, and IP receptors. The dose range for the standard agonist for human recombinant TP receptors was from 10 −12 M to 10 −6 M. HBSS-HEPES buffer was used as the negative control for the standard agonists. Cells were excited with LED (light emitting diode) excitation at 470-495 nm and emission was measured through an emission filter at 515-575 nm. Assay plates were read for 3.5 minutes using the FLIPR TETRA . The peak increase in fluorescence intensity was recorded for each well. On each plate, negative controls, dose response of positive controls, and co-treatments of antagonist-agonist for each dose were in triplicates. Standard agonists were as follows: DP=BW 245C, EP 1 -EP 4 =PGE 2 , FP=17-phenyl-PGF 2α , IP=Cicaprost, and TP=U-46619. The peak fluorescence change in each well containing drug was expressed relative to vehicle controls with the standard agonist at 10 −6 M (the positive control). To obtain concentration-response curves, compounds were tested in triplicate in each plate over the desired concentration range.
Ca 2+ Signal Studies on Human Recombinant Prostanoid Receptor DP 2
[0191] FLIPR functional assays were conducted at Millipore to monitor the activity anti-asthmatic against human DP 2 receptors stably expressed in the Chem-5 proprietary host cell line generated by Millipore. Prior to standard agonist addition, the compounds were spotted at 10 μM along with vehicle control (1% Ethanol in HBSS-HEPES buffer) across the assay wells. The assay plate was incubated at room temperature for 10 minutes in the dark. Then an 8-point serial dilution dose response from 10 −12 M to 10 −5 M of the standard agonist PGD 2 was performed. Assay plates were read for 90 seconds using the FLIPR TETRA . The fluorescence measurements were collected to calculate IC 50 values. The assays were done at least 3 times to give n=3.
Data Processing
[0192] All plates were subjected to appropriate baseline corrections. Maximum fluorescence values were exported. The raw data of n=1 was first processed by Activity Base using nonlinear regression curve fit to calculate the percentage activity of each data point relative to the positive control (=10 −6 M of the standard agonist). Then n=3 of this data were exported to GraphPad Prism 4 to calculate the average EC 50 of the standard agonist, and the IC 50 (the concentration of the antagonist required to inhibit half the standard agonist activity) were calculated using nonlinear regression curve fit, with constraints of bottom constant equal to 0 and top constant equal to 100. Calculation of Kb=[Antagonist Concentration]/(IC 50 /EC 50 −1). When no antagonism was detected or when Kb≧10,000 nM, the antagonist is defined as not active (NA).
[0193] The results of the above testing are reported in TABLE 1, below.
[0000]
TABLE 1
Example No.
FP
DP 1
EP 1
EP 2
EP 3
EP 4
IP
TP
1
140
280
22
3100
1400
150
620
12
4a
110
280
80
4500
NA
180
1200
3
5
63
220
24
3400
NA
240
6800
7
3a
180
220
71
2900
7100
68
1100
5
4
75
240
24
1200
7800
120
1600
30
3
75
140
40
2300
NA
85
1600
9
(FLIPR) K b (nM), NA = inactive
[0194] As shown in TABLE 1, the preferred compounds of this invention are pan antagonists having activity at the FP, DP, EP 1 , EP 4 and TP receptors, but are inactive at the EP 2 and EP 3 receptors. Thus, these compounds have a biological selectivity profile making them useful in treating diseases and conditions which are mediated by the EP 2 and/or EP 3 receptors, without the side effects mediated by the FP, DP, EP 1 , EP 4 and TP receptors.
[0195] Thus, the compounds of this invention compound may be administered to treat DP1, FP, EP1, TP and/or EP4 receptor mediated diseases or conditions.
[0196] For example, said condition or disease may be related to inflammation, or said DP1, FP, EP1, TP and/or EP4 receptor mediated condition or disease may be selected from the group consisting of allergic conditions, asthma, allergic asthma, allergic rhinitis, uveitis and related disorders, atherosclerosis, blood coagulation disorders, bone disorders, cancer, cellular neoplastic transformations, chronic obstructive pulmonary diseases and other forms of lung inflammation, congestive heart failure, diabetic retinopathy, diseases or conditions requiring a treatment of anti-coagulation, diseases requiring control of bone formation and resorption, fertility disorders, gangrene, glaucoma, hyperpyrexia, immune and autoimmune diseases, inflammatory conditions, metastic tumor growth, migraine, mucus secretion disorders, nasal congestion, nasal inflammation, occlusive vascular diseases, ocular hypertension, ocular hypotension, osteoporosis, rheumatoid arthritis, pain, perennial rhinitis, pulmonary congestion, pulmonary hypotension, Raynaud's disease, rejection in organ transplant and by-pass surgery, respiratory conditions, hirsutism, rhinorrhea, shock, sleep disorders, and sleep-wake cycle disorders.
[0197] Said compound may be administered as a surgical adjunct in ophthalmology for cataract removal and artificial lens insertion, ocular implant procedures, photorefractive radial keratotomy and other ophthalmogical laser procedures or as a surgical adjunct in a procedure involving skin incisions, relief of pain and inflammation and scar formation/keloids post-surgery, for treating sports injuries and general aches and pains in muscles and joints.
[0198] Preferably, said DP 1 , FP, EP 1 , TP, and/or EP 4 receptor mediated condition or disease is an EP 1 and/or EP 4 receptor mediated condition or disease.
[0199] Preferably, said DP 1 , FP, EP 1 , TP and/or EP 4 receptor mediated condition or disease is an allergic condition, e.g. an dermatological allergy, or an ocular allergy, or a respiratory allergy, e.g. nasal congestion, rhinitis, and asthma.
[0200] Said condition or disease may be related to pain.
[0201] Said condition or disease may be selected from the group consisting of arthritis, migraine, and headache.
[0202] Said condition or disease may be associated with the gastrointestinal tract, wherein said condition or disease may be peptic ulcer, heartburn, reflux esophagitis, erosive esophagitis, non-ulcer dyspepsia, infection by Helicobacter pylori , alrynitis, and irritable bowel syndrome.
[0203] Said condition or disease may be selected from the group consisting of hyperalgesia and allodynia, or said condition or disease may be related to mucus secretion, wherein said mucus secretion is gastrointestinal, or occurs in the nose, sinuses, throat, or lungs.
[0204] Said condition or disease is related to abdominal cramping, e.g. said condition or disease may be irritable bowel syndrome.
[0205] Said condition or disease may be a bleeding disorder, or a sleep disorder, or mastocytosis.
[0206] Said condition or disease may be associated with elevated body temperature, or ocular hypertension and glaucoma, or ocular hypotension.
[0207] Said condition may relate to surgical produres to treat pain, inflammation and other unwanted sequelae wherein said surgical procedure includes incision, laser surgery or implantation.
[0208] The present invention also relates to a method of treating inflammation resulting from inflammatory diseases characterized by monocytic infiltration caused by the secretion of cytokines and/or chemokines by administration, to a patient in need of said treatment, of a pharmaceutical composition comprising a compound of the present invention
[0209] The current finding that the compounds of this invention are effective in attenuating the production of TNF family cytokines (TNFα), and the classical interleukin-1 (IL-1) family cytokines is especially important. These cytokines exert a broad spectrum of biological and pathological effects. They play key roles in inflammation and RA pathogenesis by stimulating the release of multiple proinflammatory cytokines, including themselves, through the NFκB signaling pathway. Although alleviating the symptoms of RA in 50-65% of patients, a TNFα antibody is very expensive to use compared to chemically synthesized small molecules, inconvenient to administer usually requiring injections, and has been linked to tuberculosis, lymphoma, and other adverse effects. Unlike a TNFα antibody that totally eliminates all circulating TNFα in the system; the compounds of this invention only attenuate the production of TNFα by inhibiting proinflammatory PG receptors. Therefore the adverse effects associated with a TNFα antibody in elevating infectious and cancerous tendency is less likely.
[0210] Proinflammatory elements TNF, RANTES, and MCP-1 are involved in the cascade of events in the early and late stages of atherosclerosis. Plasma MCP-1 levels have been linked to cardiovascular disease risk factors in clinical studies. Platelet activation leads to the release of MIP-1α, RANTES, and IL-8, which attract leukocytes and further activate other platelets. These evidences provide a direct linkage between homeostasis, infection, and inflammation and the development of atherosclerosis. The compounds of this invention are able to target multiple biomarkers of inflammation, thrombosis, and atherothrombosis simultaneously, which may confer pharmaceutical potential on the compounds of this invention in treating atherosclerosis and atherothrombosis. As a result, the compounds of this invention are unlikely to be associated with cardiovascular liability as in the case of the COXIBs, conversely it may even have a beneficial effect on cardiovascular function.
[0211] In summary, because of their ability to suppress the synthesis of some key proinflammatory cytokines/chemokines IL-8, MCP-1, MDC, RANTES, and TNFα, the compounds of the present invention are not only at least as effective as COXIBs and NSAIDs in RA treatment, but also are a safer therapy in RA treatment. They are also a potential therapy for cardiovascular diseases.
[0212] The compounds of this invention treat or prevent inflammation at least in part by the decreasing the amount of the secretion of certain cytokines and/or chemokines that result from the exposure of the patient to a stimulant.
[0213] In particular, the secretion of VEGF, MIP-1β, IL-8, MCP-1, . . . , MDC, and RANTES is reduced in those instances where said secretions are triggered by lipopolysaccharides (LPS) and or TNFα.
[0214] Interleukin-8 (IL-8): functions as a potent chemoattractantsand activator of neutrophils, IL-8 is produced in response to stimulation with either IL-1 or TNFα. IL-8 not only accounts for a significant proportion of the chemotactic activity for neutrophils in rheumatoid arthritis (RA) synovial fluids, but also is a potent angiogenic factor in the RA synovium.
[0215] Monocyte chemoattractant protein-1 (MCP-1, or CCL-2): is not only believed to play a role in inflammatory diseases characterized by monocytic infiltration, such as RA rheumatoid arthritis, psoriasis, and atherosclerosis, but is also implicated in other diseases, such as atopic dermatitis, renal disease, pleurisy, allergy and asthma, colitis, endometriosis, polymyositis and dermatomyositis, uveitis, restenosis, brain inflammation and obesity. MCP-1 also controls leukocyte trafficking in vascular cells involved in diabetes and diabetes-induced atherosclerosis. MCP-1 antibodies are potential therapeutic agents for treating MCP-1/CCR2-mediated multiple inflammatory diseases.
[0216] Tumor necrosis factor α (TNFα): mainly secreted by macrophages and recognized for its importance in activating the cytokine cascade. TNFα stimulates the production of proinflammatory cytokines/chemokines, collagenases, metalloproteinases, and other inflammatory mediators; activates endothelial cells and neutrophils; promotes T- and B-cell growth, as well as stimulating bone resorption. The TNFα antibody infliximab not only decreases the production of local and systemic proinflammatory cytokines/chemokines, but also reduces serum MMP-3 production, nitric oxide synthase activity, VEGF release, and angiogenesis in inflamed joints.
[0217] Macrophage-derived chemokine (MDC) induces chemotaxis for monocyte-derived dendritic cells, activated T cells and natural killer (NK) cells (Ho et al., 2003). Highly expressed by the three major cell types involved in allergic inflammation: eosinophils, basophils, and Th2 lymphocytes (Garcia et al., 2005), as well as highly expressed in atopic dermatitis (Pivarcsi et al., 2005), MDC plays a role in inflammatory diseases such as allergic asthma and atopic dermatitis (Ho et al., 2003). Significantly enhanced in keratinocytes of patients with atopic dermatitis, MDC could be a candidate therapeutic target for inflammatory skin disease such as atopic dermatitis (Qi et al., 2009). MDC is also implicated in disease activity of RA. After combination treatment with the disease-modifying anti-rheumatic drugs leflunomide and methotrexate in RA patients, plasma MCP-1 and MDC concentrations were significantly lower, and so was the recruitment of inflammatory cells into the sites of inflammation (Ho et al., 2003). Moreover, MDC also amplify platelet activation and has been associated with the pathogenesis of atherosclerotic disease including thrombosis (Gleissner et al., 2008).
[0218] Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) is a chemoattractant for blood monocytes, memory T-helper cells and eosinophils, and plays an active role in recruiting leukocytes into inflammatory sites. It also stimulates the release of histamine from basophils, activates eosinophils and causes hypodense eosinophils, which is associated with diseases such as asthma and allergic rhinitis. RANTES receptor CCR5 is also expressed on cells involved in atherosclerosis (e.g. monocytes/macrophages, T lymphocytes, or Th1-type cells), and is specialized in mediating RANTES-triggered atherosclerotic plaque formation (Zernecke et al., 2008). Like MCP-1, stimulation with RANTES enhances production of IL-6 and IL-8 in RA fibroblast-like synovial cells; elevated MMP-3 production by chondrocytes, and inhibited proteoglycan synthesis and enhanced proteoglycan release from the chondrocytes (Iwamoto et al., 2008). Both MCP-1 and RANTES were found to play an important role in allergic lung inflammation, lung leukocyte infiltration, bronchial hyper-responsiveness, and the recruitment of eosinophils in the pathogenesis of asthma (Conti et al., 2001). Similar to MCP-1, RANTES also enhances the inflammatory response within the nervous system, which plays an apparent role in the pathogenesis of multiple sclerosis (Conti et al., 2001). Inhibitors for RANTES may provide clinical benefits in treating inflammation, CNS disorders, parasitic disease, cancer, autoimmune and heart diseases (Castellani et al., 2007).
[0219] While the use of the compounds of this invention are shown to decrease the secretion of the above cytokines in FIGS. 2 through 9 , it is believed that the compounds of this invention are effective to decrease the secretion of ENA-7, PAI-1, CD-10, G-CSF, GM-CSF, IL-1{acute over (α)} and IL-18, as well.
[0220] The compounds of this invention are also tested for efficacy in treating uveitis as described below.
Arachidonate Induced Uveitis
[0221] The rational for this protocol is to use arachidonate to directly produce ocular anterior segment uveitis, as opposed to using lipopolysaccharide (LPS) to indirectly release arachidonic acid.
Induction of Uveitis:
[0222] Conscious male or female Dutch-belted pigmented rabbits weighing 2.5-3 kg were used for all in vivo slit lamp studies. Four animals were employed per test group. The right eye of each animal receiving 35 μl of topically administered test and the contralateral left eye of each animal receiving 35 μl of topically administered vehicle (t=0 minutes), followed 30 minutes later by treatment with 35 μl of 0.5% sodium arachidonate onto the surface of both eyes (t=30 minutes). Both eyes were examined by slit lamp 60 minutes following sodium arachdionate challenge (t=90 minutes) at 16× magnification under both white light and blue light illumination at an approximate angle of 45° through 1 mm and 5 mm slit widths.
Measurement of Anterior Chamber Leukocyte Infiltration:
[0223] Anterior chamber leukocyte infiltration was measured using a numerical scoring system to estimate cell number per field defined by a 5 mm slit width: 0=no cells per field (no response); 1=1-10 cells per field (mild); 2=11-20 cells per field (moderate); 3=26-50 cells per field (severe); 4=>50 cells per filed (florid). Results are reported as the mean score value±S.E.M.
[0224] The results are shown in FIG. 12 . In FIG. 12 the compounds of Example 3 and 3a were tested at concentrations of 0.1, 0.3 and 1% and a dose dependent response was observed for each compound.
[0225] The compounds of this invention were tested according to the method described in “Characterization of Receptor Subtypes Involved in Prostanoid-Induced Conjunctival Pruritis and Their Role in Mediating Conjunctival Itching”, Vol. 279, No. 1, (JPET)279, 137-142′ 1996 for their efficacy in alleviating itch. The results are reported in FIGS. 10 and 11 . The results in both experiments showed a significantly lower number of itch-scratch episodes with the use of the compounds of FIGS. 3 ans 3 ( a ) thereby indicating that the compounds of this invention are useful in treating allergic conjunctivitis.
[0226] The compounds of FIGS. 3 and 3( a ) were tested for mutagenicity by means of the Ames Test using Strains TA 98 and TA 100. The results were negative for both compounds.
[0227] Finally, said condition that may be treated with the compounds of this invention may be related to pain and inflammation and post-surgical scar and keloid formation.
[0228] In view of the various diseases and conditions that may be treated with the compositions of this invention there is provided a pharmaceutical product comprising a compound having the following formula
[0000]
Wherein R 1 is selected from the group consisting of OR 7 , N(R 7 ) 2 , and N(R 7 )SO 2 R 7 wherein R 7 is selected from the group consisting of H, alkyl and aryl, wherein said alkyl and aryl may be substituted with fluoro;
R 2 is selected from the group consisting of H and alkyl;
R 3 is selected from the group consisting of H and alkyl; wherein R 2 and R 3 , individually or together, can form a cycloalkyl ring;
X is (CH 2 ) n wherein n is 0 or an integer of from 1 to 3; provided however that when n is 0 or 1, R 1 is not OR 7 . or NR 2 ;
R 4 is selected from the group consisting of H, alkyl and fluoroalkyl;
R 5 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy or aryloxy;
R 6 is selected from the group consisting of H, hydroxy, alkyl, aryl, alkoxy, aryloxy, halogen, nitro, amino, cyano and hydroxy, halogen, nitro, amino and cyano-substituted alkyl, aryl, alkoxy and aryloxy;
Z is (CH 2 ) m wherein m is 0 or an integer of from 1 to 3:
Y is selected from the group consisting of O, S, SO, SO 2 and (CH 2 ) p , wherein p is 0 or an integer of from 1 to 3; and
W is selected from the group consisting of alkyl and aryl
or a pharmaceutically acceptable salt or a prodrug thereof, wherein said product is packaged and labeled for the treatment or prevention of a disease or condition selected from the group consisting of uveitis, allergic conditions, asthma, allergic asthma, allergic rhinitis, atherosclerosis, blood coagulation disorders, bone disorders, cancer, cellular neoplastic transformations, chronic obstructive pulmonary diseases and other forms of lung inflammation, congestive heart failure, diabetic retinopathy, diseases or conditions requiring a treatment of anti-coagulation, diseases requiring control of bone formation and resorption, fertility disorders, hyperpyrexia, gangrene, glaucoma, hypothermia, immune and autoimmune diseases, inflammatory conditions, metastic tumor growth, migraine, mucus secretion disorders, nasal congestion, nasal inflammation, occlusive vascular diseases, ocular hypertension, ocular hypotension, osteoporosis, pain, perennial rhinitis, pulmonary congestion, pulmonary hypotension, Raynaud's disease, rejection in organ transplant and by-pass surgery, respiratory conditions, rheumatoid arthritis, rhinorrhea, shock, sleep disorders, sleep-wake cycle disorders, sports injuries, muscle aches and pains, and surgical adjunct for minimizing pain, inflammation and scar/keloid formation.
[0239] Those skilled in the art will readily understand that for administration the compounds disclosed herein can be admixed with pharmaceutically acceptable excipients which, per se, are well known in the art. Specifically, a drug to be administered systemically, it may be formulated as a powder, pill, tablet or the like, or as a solution, emulsion, suspension, aerosol, syrup or elixir suitable for oral or parenteral administration or inhalation.
[0240] For solid dosage forms, non-toxic solid carriers include, but are not limited to, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, the polyalkylene glycols, talcum, cellulose, glucose, sucrose and magnesium carbonate.
[0241] The solid dosage forms may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distcarate may be employed. They may also be coated by the technique described in the U.S. Pat. Nos. 4,256,108; 4,166,452; and 4,265,874 to form osmotic therapeutic tablets for control release. Liquid pharmaceutically administrable dosage forms can, for example, comprise a solution or suspension of one or more of the compounds of the present invention and optional pharmaceutical adjutants in a carrier, such as for example, water, saline, aqueous dextrose, glycerol, ethanol and the like, to thereby form a solution or suspension. If desired, the pharmaceutical composition to be administered may also contain minor amounts of nontoxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like. Typical examples of such auxiliary agents are sodium acetate, sorbitan monolaurate, triethanolamine, sodium acetate, triethanolamine oleate, etc. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 16th Edition, 1980. The composition of the formulation to be administered, in any event, contains a quantity of one or more of the presently useful compounds in an amount effective to provide the desired therapeutic effect.
[0242] Parenteral administration is generally characterized by injection, either subcutaneously, intramuscularly or intravenously. Injectable formulations can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol and the like. In addition, if desired, the injectable pharmaceutical compositions to be administered may also contain minor amounts of non-toxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like.
[0243] The amount of the presently useful compound or compounds of the present invention administered is, of course, dependent on the therapeutic effect or effects desired, on the specific mammal being treated, on the severity and nature of the mammal's condition, on the manner of administration, on the potency and pharmacodynamics of the particular compound or compounds employed, and on the judgment of the prescribing physician. The therapeutically effective dosage of the presently useful compound or compounds is preferably in the range of about 0.5 ng/kg/day or about 1 ng/kg/day to about 100 mg/kg/day.
[0244] For ophthalmic application, solutions are often prepared using a physiological saline solution as a major vehicle. Ophthalmic solutions should preferably be maintained at a comfortable pH with an appropriate buffer system. The formulations may also contain conventional, pharmaceutically acceptable preservatives, stabilizers and surfactants.
[0245] Preservatives that may be used in the pharmaceutical compositions of the present invention include, but are not limited to, benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetate and phenylmercuric nitrate. A useful surfactant is, for example, Tween 80. Likewise, various useful vehicles may be used in the ophthalmic preparations of the present invention. These vehicles include, but are not limited to, polyvinyl alcohol, povidone, hydroxypropyl methyl cellulose, poloxamers, carboxymethyl cellulose, hydroxyethyl cellulose and purified water.
[0246] Tonicity adjustors may be added as needed or convenient. They include, but are not limited to, salts, particularly sodium chloride, potassium chloride, mannitol and glycerin, or any other suitable ophthalmically acceptable tonicity adjustor.
[0247] Various buffers and means for adjusting pH may be used so long as the resulting preparation is ophthalmically acceptable. Accordingly, buffers include acetate buffers, citrate buffers, phosphate buffers and borate buffers. Acids or bases may be used to adjust the pH of these formulations as needed.
[0248] Similarly, an ophthalmically acceptable antioxidant for use in the present invention includes, but is not limited to, sodium metabisulfite, sodium thiosulfate, acetylcysteine, butylated hydroxyanisole and butylated hydroxytoluene.
[0249] Other excipient components which may be included in the ophthalmic preparations are chelating agents. A useful chelating agent is edentate disodium, although other chelating agents may also be used in place or in conjunction with it.
[0250] For topical use, creams, ointments, gels, solutions or suspensions, etc., containing the compound of the present invention are employed. Topical formulations may generally be comprised of a pharmaceutical carrier, cosolvent, emulsifier, penetration enhancer, preservative system, and emollient.
[0251] The actual dose of the compounds of the present invention depends on the specific compound, and on the condition to be treated; the selection of the appropriate dose is well within the knowledge of the skilled artisan.
[0252] The present invention is not to be limited in scope by the exemplified embodiments, which are only intended as illustrations of specific aspects of the invention. Various modifications of the invention, in addition to those disclosed herein, will be apparent to those skilled in the art by a careful reading of the specification, including the claims, as originally filed. It is intended that all such modifications will fall within the scope of the appended claims
|
The present invention provides a compound, that is a 1-[(2-{[(alkyl or aryl)methyl]oxyl}halo or haloalkyl substituted-phenyl)alkyl]-5-hydrocarbyl or substituted hydrocarbyl-1H-pyrazole carboxylic acid or alkylenylcarboxylic acid or a hydrocarbyl or substituted hydrocarbyl sulfonamide of said carboxylic acid or said alkylenylcarboxylic acid, provided however said compound is not a 3-carboxylic acid, a sulfonamide thereof, or a 3-methylenylcarboxylic acid. The compound may be represented by the following formula (I). Wherein R1, R2, R3, R4, R5, R6, X, W, X and Y are as defined in the specification. The compounds may be administered to treat DP1, FP, EP1, TP and/or EP4 receptor mediated diseases or conditions.
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BACKGROUND OF THE INVENTION
This invention relates to gas generators in general and more particularly to a method for starting up a gas generator for the catalytic reaction of hydrocarbons with an oxygen containing gas to form a fuel gas and for starting up an internal combustion engine which is to be supplied with the fuel gas, wherein catalytic material is temporarily electrically heated in a reaction chamber containing a catalytic charge; a mixture of hydrocarbons and air, richer in oxygen than the mixture used in continuous operation, is conducted over the catalytic material, is reacted there exothermically for further heating of the catalytic charge, and the fuel gas produced is fed to the internal combustion engine; as well as apparatus for implementing this method.
Gas generators can be used, for instance, to catalytically convert hydrocarbon containing fuels into a fuel gas which is better suited for the operation of internal combustion engines than liquid fuel. For, in internal combustion engines supplied with liquid fuel, for instance, in motor vehicles, the incomplete evaporation of the fuel and the uneven mixing with combustion air lead to incomplete combustion and emission of harmful substances. In addition, antiknock agents must as a rule be admixed to the fuel causing the content of substances in the exhaust gas which are harmful to the health to be increased further. The hazardous pollution of the air can largely be prevented if the internal combustion engine is operated with fuel gas. This fuel gas can be generated, as is described, for instance, in the U.S. Patent Application Ser. No. 633,609, in a reformed gas generator by partial catalytic oxidation of evaporated or vaporized liquid fuel with an oxygen containing gas, and the fuel gas then burned, together with additional combustion air, in the internal combustion engine. Since this fuel gas (reformed gas) has a high octane number, the addition of antiknock agents is not required.
A mixture of air and exhaust gas of the internal combustion engine, for instance, can be used as the oxygen containing gas for the reaction where the reaction is endothermic if the exhaust gas content is high and exothermic if the air content is high. To carry out the reaction, the catalyst must have an operating temperature which is above the start up temperature of the catalyst, the start up temperature of a catalyst being understood, as usual, to be that temperature at which the effect of the catalyst leads to a noticeable reaction. The operating temperature can be maintained by supplying heat to the generator from the outside, for instance, through an exchange with the hot exhaust gases of the internal combustion engine or by a supplemental electric heater. However, the temperature of the catalyst can also be controlled by changing the composition of the oxygen containing gas, i.e., the air/exhaust gas mixture, and by changing the thermal balance of the reaction accordingly. Thus, a compensation of the heat losses of the generator can be achieved by a light exothermic reaction.
In one known device a combustion chamber with a flame ignition plug is arranged at the entrance of the reaction chamber. In the combustion chamber a gasoline/air mixture is ignited simultaneously with the starting of the internal combustion engine connected to the reformed gas generator. The flaming combustion of the gasoline produces hot flame gases which are drawn by the internal combustion engine through the reaction chamber together with a further reaction mixture of gasoline and combustion air. These gases heat the catalytic charge contained therein up to the start up temperature of the catalyst. From then on, the reaction mixture in the reformed gas generator itself is reacted and the flame is extinguished.
In U.S. Pat. No. 3,954,423 and in U.S. Application Ser. No. 633,609, further starting devices which precede the inlet to the reaction chamber of the reformed gas generator, which consist of a starting generator with a separate starting catalyst of small volume are described. Upon starting the internal combustion engine, a gasoline/air mixture is also ignited in the starting generator. The hot flame gases of the latter are drawn by the internal combustion engine through the starting catalyst and heat the latter up quickly. Then, a gasoline/air mixture is fed to the starting catalyst and is converted there into a hot fuel gas which in turn is drawn, for heating up the catalytic charge of the reformed gas generator, through the reaction chamber of the latter. At the same time, the flame is extinguished. This generates a fuel gas with which the internal combustion engine can be operated without load, shortly after the internal combustion engine is started, even before the reformed gas generator itself is heated up to the operating temperature. However, the starting generator, which precedes the inlet to the reaction chamber, requires additional space of its own, although such space is relatively small.
In U.S. Pat. No. 3,915,125, a starting procedure is described which makes use of an electric starting device which is arranged in the interior of the reaction chamber and precedes at least part of the catalyst in the flow direction. This starting device may consist, for instance, of incandescent electric wires which are coated with catalytic material and are connected into an external circuit. To start the generator, the internal combustion engine is driven, for instance, by an electric starter, the external circuit is closed and a slightly understoichiometric hydrocarbon/air mixture is ignited at the incandescent wires. The strongly exothermic reaction initiated thereby, which may take place with a flame or will at least have a tendency to an ignition, allows hot gases to be produced which heat the catalytic charge to above the start up temperature of the catalyst. The reaction of the hydrocarbon/air mixture can also be initiated at an electric starting device which consists of an electric heater resistor of catalytic material. This heater resistor is heated by an external circuit until the catalytic charge is heated above the start up temperature of the catalyst. At the same time, with the further heating of the catalytic charge the throughput of hydrocarbons is increased step by step and the air supply is throttled until the catalyst is heated to a reaction temperature suited for continuous operation and the transition to continuous operation can be made.
In all known devices and starting methods, the hydrocarbon fuel is overstoichiometrically or slightly understoichiometrically reacted with air during starting, so that a short starting time of the gas generator is achieved through violent development of heat and the internal combustion engine, which is to be operated with the fuel gas produced, can be put in operation quickly. It is a disadvantage in such operation that, with this relatively large supply of air, in the flame gases and at the catalyst initiating the reaction, temperatures occur which may lead to damage of the temperature sensitive catalysts. In the interest of greater safety, moreover, methods would be preferable, in which a flame reaction of the reaction mixture is avoided. In addition, a product gas is generated, at the beginning of the starting process, which has only a low calorific value and which must be drawn through the generator by the internal combustion engine in order to heat up the catalytic charge. However, to accomplish this, the internal combustion engine must first be kept running by an external energy source until the generator produces a gas with a calorific value sufficient to operate the internal combustion engine. In this last described prior art method, the vehicle's external energy source, e.g., the starter battery is simultaneously loaded by the start up heater and by the starter motor.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus for starting a gas generator for generating fuel gas, and for starting an internal combustion engine to be supplied with the fuel gas, using an electrical start up heater in such a manner that no flame reaction takes place in the gas generator and thus, the occurrence of excessively high temperatures is avoided.
A further object is to avoid a condition where the starter battery has to supply an excessively large amount of power even for a short time.
Further objects are to insure that the gas generator delivers a fuel gas with sufficient calorific value even after a short start up time and that the device required for the starting process has a few additional components and requires as little space as possible.
According to the present invention, this problem is solved by electrically heating a small part of the volume of the catalytic charge at least to the start up temperature of the catalyst; terminating the electrical heating, driving the internal combustion engine, introducing the hydrocarbon/air mixture, reacting it at the heated part of the volume without flame and further heating the catalytic charge by the spreading of the exothermic reaction, and finally, feeding the hydrocarbons and the oxygen containing gas, to the generator with an oxygen component provided for the reaction in continuous operation after the catalytic charge is sufficiently hot.
The method according to the present invention thus proceeds in two stages. First, with the supply of hydrocarbon and air shut off, an electric start up heater, which is preferably embedded in the catalytic charge, is switched on and quickly heats up part of the volume of the catalytic charge. The temperature of this subvolume reaches the start up temperature of the catalytic material within a few seconds. For example, a subvolume of catalyst which, together with the fuel gas produced by reaction in the subvolume and, if necessary, with additional, unreacted hydrocarbons, in just sufficient to cover the demand of the internal combustion engine when idling can be heated up.
At the beginning of the second stage, the start up heater is switched off. Simultaneously or immediately thereafter, the hydrocarbon/air mixture is fed in and the internal combustion engine is started, for instance, electrically. By its suction, the reaction mixture is drawn through the generator. Since the start up heater is already switched off, the starter battery is not overloaded by the simultaneous operation of the start up heater and the starter motor. At first, the air content in the reaction mixture is increased over that of continuous operation. Where the air number λ is understood to mean the ratio of the amount of air supplied to the amount of air required for stoichiometric combustion (λ = 1) of the hydrocarbons employed, then the air number of the mixture drawn in during the second starting phase can advantageously lie between about 0.3 and 0.4. If there are no cavities in the reaction chamber of the generator for a flame to develop, flame combustion is not possible with air numbers below 0.5. The fuel gas produced then also has a calorific value sufficient for the internal combustion engine to start up. The reaction zone of the exothermal reaction now spreads and heats up the catalytic charge quickly to the extent that in the continuous operation which follows the starting process, and during which the air number in the reaction mixture supplied is throttled down, the reaction mixture can be converted in the heated parts. If the internal combustion engine is not at first operated at full load after the starting process is completed, then it is not necessary to wait for continuous operation until almost the entire catalytic charge is heated to the operating temperature. As a rule, it will then be sufficient if part of the catalytic charge has reached the operating temperature. Even if the reaction mixture is at first not completely reacted, in the heated parts of the catalytic charge, a small content of unreacted fuel gases in the generated gas mixture will not lead to operating difficulties.
The method requires no voluminous components for its implementation. In addition, it ensures a quick and operationally safe starting of the generator and the internal combustion engine without excessively loading an external energy source.
It is advantageous to apportion the amount of the hydrocarbons supplied during the second start up phase in such a manner that the generated mixture of fuel and, possibly, unreacted hydrocarbons covers, but not substantially exceeds, the demand on the internal combustion engine when idling. The internal combustion engine can then keep running by itself during the second start up phase.
It is particularly advantageous if a part of the volume of the catalytic charge which is in the proximity of the outlet of the reaction chamber is heated electrically. In the reaction chamber of the gas generator, which is designed for continuous operation with a lower air number, i.e., for a less strongly exothermic reaction, the reaction of the more oxygen rich mixture first spreads in the catalytic charge. If the mixture is introduced here via the inlet of the reaction chamber, then the reaction takes place in a relatively narrow reaction zone which travels against the flow direction toward the inlet. Thus, layers of the catalytic charge lying one behind the other are heated up quickly, without the reaction always occurring in the same zones of the catalytic charge, which might heat up too much in this manner.
It is even more advantageous to feed at least part of the mixture directly to the heated subvolume, for instance, via an auxiliary feed line. After the reaction has spread through the catalytic charge, the mixture can then be fed to the entrance of the reaction chamber and the auxiliary feed line shut off.
Other reactors in which a reaction mixture is reacted exothermically at a catalyst can also be started in this manner. To this end, a partial volume of the catalyst adjacent to the outlet of the reaction chamber is first heated. This can be accomplished by electrical heating and a heavily exothermic reaction which takes place in this heated subvolume. Now, the reaction mixture is fed to the reaction chamber via the inlet with a composition which leads to a more strongly exothermic reaction than in continuous operation. The reaction front of the incipient reaction travels quickly through the catalyst toward the inlet. If the catalyst is sufficiently hot, then the reaction mixture can be fed into the reaction chamber with a composition sufficient for continuous operation. The reaction travels through the reaction chamber even more quickly if, during the starting process, the supply of the reaction mixture is throttled below the supply used in continuous operation, for which the reactor is designed. In some cases, for instance, with cylindrical catalyst chambers, this migration can also be achieved by throttling the supply alone without changing the composition of the reaction mixture.
When the internal combustion engine has exceeded a minimum speed sufficient for driving the electric generator, the reaction chamber can advantageously be heated if the temperature falls below the operating temperature. A temperature drop could be due, for instance, to interference in the gasoline supply and can be prevented by an electric heater, the energy for which is supplied, for instance, by the electric generator driven by the internal combustion engine itself.
The method according to the present invention is advantageously implemented with a generator which comprises a reaction chamber containing a catalytic charge, lines with metering devices for the supply of hydrocarbons and air to the reaction chamber, and an electric start up heater arranged in the reaction chamber, this electric start up heater being embedded in the catalytic charge. The start up heater is preferably embedded in a part of the catalytic charge, which is disposed in the vicinity of the outlet of the reaction chamber. The start up heater is preferably designed, with respect to the heating area and energy consumption, in such a manner that within a short time, at most within a few seconds, a part of the catalytic charge having a volume sufficient for the catalytic generation of an amount of fuel gas which largely covers the demand of the internal combustion engine when idling is heated up.
In order to keep the energy consumption low during the heating up period, the start up heater can advantageously be embedded in a catalytic material with a heat capacity as low as possible. At least the part of the catalytic charge surrounding the start up heater consists preferably of porous, ceramic hollow spheres or of inorganic fibers. For instance, hollow spheres of α-aluminum oxide with about 2 to 3 mm diameter can be considered. These are commercially available as what is known as spherical corundum. Also a layer of felt-like fibers, such as quartz glass wool or aluminum oxide wool, is highly suited. The aluminum oxide can be additionally impregnated with catalytically active components. At temperatures between 750° and 800° C., the reaction of hydrocarbons with air sets in at such materials to form a fuel gas containing CO, CO 2 , H 2 and CH 4 with a worthwhile yield.
In a particularly advantageous embodiment of the starting device, an auxiliary feed line opens into the reaction chamber in the vicinity of the start up heater. Through this auxiliary feed line, a more oxygen rich fuel/air mixture is fed to the subvolume of the catalyst heated by the start-up heater during the second start up phase. Preferably, a temperature sensor is provided in the vicinity of the start up heater, which indicates when the start up temperature in the subvolume of the catalyst is reached. In addition, a further temperature sensor can be arranged in the reaction chamber to indicate the spreading of the hot reaction zone into the catalytic charge. A supplemental heater attached at the reaction chamber, which may be coupled, for instance, to the further temperature sensor and switched on when the internal combustion engine is running, if the temperature in the reaction chamber drops below the operating temperature is also advantageous.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross section through a start up heater designed as an insert for a generator with an auxiliary feed line.
FIG. 2 is a schematic cross section through a generator equipped with the insert of FIG. 1 for carrying out the method according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The insert 1 shown in FIG. 1 is provided with an electric heater at its lower end which protrudes into the reaction chamber of the generator. Toward this lower end an auxiliary feed line 3 for the mixture of hydrocarbon and air is directed. In the insert 1, two temperature sensors 4 and 5 are also attached. The first temperature sensor 4 is arranged in the vicinity of the electric heater coil 2, and the other temperature sensor 5 at some distance therefrom. The lead wires of the electric heater coil, not shown in the figure, and the connecting cables 6 and 7 of the temperature sensors are surrounded by an insulating jacket and are brought out of the insert 1 to the control devices of the generator.
The generator shown in FIG. 2 consists of a cylindrical reaction chamber 10, which is surrounded by a double walled jacket 11 filled with insulating material. Chamber 10 has an inlet 12 for the raw materials of the reaction at one end and an outlet 13 for the product gas at the other end. The insert 1, of FIG. 1, with the parts labelled with the same reference numerals as FIG. 1, protrudes into the reaction chamber up to the outlet 13. A heater plug 15 with an electric heater winding 16 and connecting leads 17 protrudes further into the reaction chamber as a supplemental heater. The hydrocarbons and the oxygen containing gas are conducted via supply lines 18, which are equipped with adjustable metering valves 19, to a three-way valve 20, through which they are fed as desired to the auxiliary feed line 3 or to the inlet 12 of the reaction chamber 10.
The reaction chamber contains a bed of catalyst, e.g., spherical hollow bodies 14 of α-Al 2 O 3 , known as spherical corundum, with a diameter of about 2 to 3 mm. The outlet of the reaction chamber is closed off by a plug 35 of aluminum oxide wool.
A heater coil 2 is embedded in the spherical corundum bed. It is fused into a quartz cylinder forming a heating surface of about 4 cm 2 and electricaly heats the catalytic material surrounding the heater surface to a depth of about two spherical corundum diameters.
However, the heater coil 2 can also be embedded in the aluminum oxide wool. The start up temperature of the aluminum oxide for the reaction of hydrocarbons such as gasoline, with air is at about 750° C., and at air numbers between 0.3 and 0.4. Reaction temperatures of between 800° and 1200° C. are obtained. For continuous operation, temperatures of about 900° C. and air numbers of between 0.1 and 0.3 are provided. The aluminum oxide may also be impregnated with an additional active component in order to catalyze, for instance, an endothermic reaction of hydrocarbons with an air/exhaust gas mixture.
In a series of tests, the generator shown in the figures was started by applying a voltage of 10 V from a voltage source to the terminals 8 of the start up heater 2. With a heater area of about 4 cm 2 and a current drain of about 17 amps, electric energy of less than 1 watt was required for the start up heater to bring the corundum spheres surrounding the start up heater to the start up temperature of about 750° C. Within 10 to 20 seconds, the temperature sensor 4 signalled via an indicator lamp connected to its connecting lead 6 that the start up temperature was reached. The start up heater was turned off and a hydrocarbon/air mixture was conducted into the reaction chamber. For this purpose, the one input of the three-way valve 20 was connected to a compressor for the air and the other input to a gasoline tank. The compressor was also connected with the gasoline tank via a branch line, to let the gasoline, which served as the hydrocarbon containing fuel, flow under pressure to the three-way valve 20. At the throttling devices 19, a gasoline/air mixture was adjusted which had a throughput of about 0.3 l/hr and an air number of about 0.35. By setting the three-way valve accordingly, the mixture was conducted via the auxiliary feed line 3 to the hot catalyst material, where the gasoline was evaporated and reached. After less than a minute, the temperature sensor 5 also indicated via an indicator lamp connected to its cable 7 that now, a larger volume of catalyst was heated to temperatures of between 800° and 900° C. The supply of the reaction mixture was then switched from the auxiliary feed line 3 to the inlet 12 of the reactor. The reaction of the gasoline now took place in a relatively narrow reaction zone, which could be recognized by the glowing of the spherical corundum and which moved toward the reactor inlet 12 rapidly, even after the air number had been throttled down from 0.35 to 0.2. Also, in this process, the remaining catalytic charge was heated up quickly. After the air supply was throttled down, a fuel gas with a higher calorific value was generated in the reactor, and when the flow of gasoline was at the same time somewhat increased, a fuel gas was obtained which was suited for down, a fuel gas with a higher calorific value was generated in the reactor, and when the flow of gasoline was at the same time somewhat increased, a fuel gas was obtained which was suited for operating the internal combustion engine at partial load, even if not yet at full load.
In this test, an internal combustion engine was not yet connected to the generator. The gasoline, using compressed air and being present in liquid form, was fed into the generator, evaporated there and reacted with the air.
Deviating from the test described in the foregoing, the gasoline/air mixture is normally transported to the internal combustion engine during operation by its own suction; a known device for gasifying, atomizing or also evaporating the gasoline, which is to be drawn in with the air, may be connected in series with the three-way valve 20.
If liquid gasoline is fed to the reaction chamber, which is also possible in operation with an internal combustion engine, the heat required for the evaporation must be supplied by the reaction itself. If in the event of a load change, the gasoline supply is increased rapidly. This can cause the temperature in the reaction chamber to drop below the start up temperature under certain conditions, if the air numbers are below 0.25. In that case, the heater plug 15 is switched on; the "on" signal to do this can be given by the temperature sensor 5. Such load changes are expected, however, only during operation with the internal combustion engine running, where the internal combustion engine can supply the heating energy required for the supplemental heater itself via its electric generator.
The method according to the present invention can also be carried out without temperature measurement during the starting phase. Thus, the experimental generator shown in FIG. 2 has also been started by carrying out the electrical heating and the switching from the auxiliary feed line 3 to the inlet 12 in accordance with a fixed timing plan. The heating time of the start up heater was predetermined and one minute after the start up heater was switched off, the gasoline supply was switched over and at the same time, the throughput was changed to about 0.8 to 3 1/hr and the air number to about 0.2, i.e., to conditions for continuous operation. At the same time, a thermostat system consisting of the temperature sensor 5 and the heater plug 15 was switched on. With the fuel gas now produced, an internal combustion engine could already be operated at partial load. In tests with a fixed heating time of the start up heater of 10 seconds, ignition occurred only sporadically; with heating times of 15 seconds, only a single misfiring occurred in 5 tests, and heating times of 20 seconds always led to a successful start of the generator.
The generator can also be started by conducting only part of the gasoline/air mixture, after the start up heater is switched off, directly to the hot catalyst volume and by conducting a further part into the reaction chamber via other inlets, e.g., the inlet 12. In this process, a mixture of reacted and unreacted gasoline is produced. However, this mixture is accepted by the internal combustion engine more easily than a mixture of unconverted gasoline and air during the conventional starting of an internal combustion engines. The generator can also be started, for instance, by still retaining the increased air number initially, while the gasoline throughput is increased when the gasoline/air supply is switched from the auxiliary feed line 3 to the inlet 12 of the reactor. Then, the auxiliary feed line can be switched off even earlier and an amount of fuel gas such that the internal combustion engine can be operated at partial load can be fed already at this time to the internal combustion engine. The starting cycle is completed by going to the lower air numbers provided for continuous operation.
The method described here can be applied to particular advantage to motor vehicles, where the starting up of the generator and the internal combustion engine connected thereto can take place in such a manner that with the first operation of the ignition key, the start up heater connected to the starter battery is switched on. In indicator lamp 4 connected to the temperature sensor 4 indicates when the start up temperature has been reached in the subvolume of the catalyst surrounding the start up heater. Via a relay or by further operation of the ignition key, the start up heater 2 is now switched off and the internal combustion engine started at the same time, the suction of which draws a gasoline/air mixture into the generator via the auxiliary feed line 3. After the catalytic charge has been heated up further, the temperature sensor 5 gives a signal to shut off the auxiliary feed line 3, and an indicator lamp connected to the temperature sensor 5 indicates that the generator is now ready for continuous operation also at higher loads. The shutting off of the auxiliary feed line 3 and throttling the air number when going to continuous operation can easily be automated through the use of an electronic control. If the internal combustion engine has exceeded the already mentioned minimum speed and if the electric generator is generating current, the thermostat unit for the reaction chamber, consisting the supplemental heater 15 and the temperature sensor 5 is switched on. Since the supplemental heater prevents the catalytic charge from cooling off, the internal combustion engine can also be fully loaded quickly after the transition to continuous operation is made. With this method of starting the motor vehicle is ready to drive shortly after the beginning of the starting process.
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A generator with a reaction chamber containing a catalytic charge for reacting liquid hydrocarbons with an oxygen containing gas to form a fuel gas is ignited by first electrically heating a part of the catalytic charge, preferably a part in front of the exit of the reaction chamber, to above the start up temperature of the catalyst. Then, the heating is terminated and an internal combustion engine which draws a hydrocarbon/air mixture with an air number higher than for normal operation over the hot volume of catalyst is started. The exothermic reaction which sets in there heats up the catalytic charge. Finally, the air number is throttled down and the transition to continuous operation is made.
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FIELD OF THE INVENTION
The present invention relates to a process for manufacturing thermosetting polymer shaped articles reinforced with long continuous fibers by pultrusion. More particularly, the invention relates to a method of pultrusion into a flexible mold.
BACKGROUND OF THE INVENTION
In a general manner, the process of manufacturing thermosetting resin articles by pultrusion is known. The usual process consists of impregnating a plurality of fibers with resin, and then passing the bulk substance into a heated chamber. At the chamber exit, the fibers coated with resin enter a heated device which gives the final shape to the product being produced, which is cured as it emerges from the device. This is done in a continuous process.
Generally, a "prepreg" is used in a pressure molding process. A prepreg is a resin-coated cloth or fiber. The resin is usually applied from a solvent solution, then dried or partially cured. In the partially cured stage it is easy to handle and will soften and mold upon heating. In the automotive industry, for example, prepregs are generally known as sheet molding compounds which are large enough sheets to mold into doors, hoods, fenders and body parts in general. Prepregs are also valuable in aircraft and aerospace industries.
The usual method of pultrusion involves the pulling of a prepreg or resin coated fibers through a mold to form a shaped article in a continuous process. This method is used to form many types of articles known in the art, and often involves pulling a prepreg through a rigid metal forming device. This way a certain shape is attained (e.g., pulling a prepreg through a mold shaped like an "I" to form an "I-beam" for construction). For a discussion regarding this technology see U.S. Pat. No. 3,567,814 to Glesner; U.S. Pat. No. 4,209,482 to Schwarz; and U.S. Pat. No. 5,084,222 to Glemet et al., all incorporated herein by reference. Additionally, for a detailed discussion of thermosets and thermosetting technology, see "Advanced Thermoset Composites: Industrial and Commercial Applications", edited by Margolis, James M., Van Nostrand Reinhold Company (New York) 1986, incorporated herein by reference.
All prior art methods, however, are limited in that all resin saturated fibers are pulled through a single rigid mold or die, and are cured to the specific shape of the mold or die in a continuous process. Prepreg is also made by pultrusion by shaping with a rigid die or mold and "staged" for later use. The term "staged" refers to the partially cured condition, which permits the prepreg to be manipulated to a desired shape. Staging can be accomplished by temperature control, or using a chemical catalyst, as known in the art. Once the prepreg is formed into a desired shape, it is then fully cured and retains its shape. Prepreg made by this method results in resin tackiness and must be separated with release sheets and frozen for shipment to users.
The present invention permits a much broader range of molding by providing a method of pultrusion into a flexible mold. Therefore, after the resin coated fibers are pulled into the flexible mold, they can be shaped or maneuvered into any desired form and staged with a latent catalyst for subsequent use, thus avoiding contamination of resin onto one's hands or clothes. The flexible mold is then removed by chemical or mechanical means.
Accordingly, it is an object of the present invention to provide a method of pultrusion comprised of pulling resin coated fibers into a flexible mold.
A further object of the present invention is to provide a method of pultrusion capable of providing a curable resin composition in a flexible and maneuverable mold, said mold capable of being manipulated manually without the need for hand or equipment protection.
An additional object of the present invention is to provide a method of pultrusion comprised of pulling resin impregnated fibers into a flexible mold, shaping said mold into a desired shape, and removing said flexible mold by mechanical or chemical means.
SUMMARY OF THE INVENTION
In accordance with these and other objects of the present invention. a method of pultrusion is provided comprised of saturating a plurality of fibers or fabrics, or a combination thereof, with a curable resin compound, to form a prepreg. Said prepreg is then pulled into a flexible mold or tubing, and then the mold (containing the prepreg) is maneuvered into a desired shape or form. That the prepreg is contained in the flexible mold permits manual manipulation of the mold without contaminating equipment or personnel. The prepreg is then permitted to cure in its desired shape, and the flexible mold is removed by mechanical or chemical means.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a view of a process by which fibers are pulled through a liquid resin.
FIG. 2 shows a pull hook connected to a fiber bundle for pultrusion.
FIG. 3 shows a pull hook connected to a fiber bundle being pultruded into a mold.
FIG. 4 shows a view of a flexible tubing or mold attached to an anchor with the fibers being drawn therein.
FIG. 5 shows a close-up view of a flexible mold support.
DETAILED DESCRIPTION OF THE INVENTION
The method of the present invention involves pultrusion of prepreg into a flexible mold. Prepreg describes a composition of resin saturated fibers, fabrics, braided sleeving, or a combination thereof. For simplicity in this description of the invention, fibers will be referred to although this is not meant to limit the scope of the invention and fabrics and/or braids can be substituted therefore. For a preferred embodiment of the invention, reinforcing fibers are used comprised of, for example but not limited to, metal, glass, polyethylene, natural fibers (e.g., cotton), thermoplastics, carbon graphite, boron, alumina, silicon carbide, and/or aramid (e.g., DuPont'a KEVLAR). Continuous fibers can be used wound together, bundled, or braided, or pieces of fibers can be used wound together, bundled, or braided.
The fibers used are coated with a matrix or saturating material that may reach an intermediate stage at which the material may be shaped, and then at a later stage be cured to a solid. The matrix or saturating material can be a thermoset such as polyester, epoxy novalac, bisphenol A epoxy, vinylester, polyimide, phenolics, and may include ceramics or combinations of the aforementioned saturating materials and ceramics or ceramic fibers. The materials used to saturate the fibers are commonly referred to as resins.
As shown in FIG. 1, the fibers i may be saturated by running them through a tub of liquid resin. The fibers are bundled at point 2, then passed into liquid resin 6, and kept submerged in liquid resin 6 by arm 3 and arm 4. The saturated fibers are then removed from the tub, and any excess resin is squeezed out at squeeze-out bushing 5. The fibers are then in a resin saturated condition and ready to be pulled into a flexible tubing and then conditioned for delayed use by staging (i.e., brought to an intermediate stage between saturation with resin and full cure or part cure) which can then be finally shaped and cured. Those in the art refer to this intermediate stage as the "B-stage", wherein the "A-stage" refers to the freshly saturated fibers, and the "C-stage" is full cure. In the "B-stage" the fibers are still capable of being manipulated.
As shown in FIG. 2, in order to pull fibers 1 through any given mold, a pull hook 7 is used. To attach fiber bundle 1 to pull hook 7, fiber bundle 1 (before saturation with liquid resin 6) is looped through pull hook 7, doubled back and wetted with a fast setting cyanoacrylate, which requires only a few minutes setting time. Fiber bundle 1 is then ready to be pulled through liquid resin 6 and into a given flexible mold or tubing.
As shown in FIG. 3, pull hook 7 with fiber bundle 1 connected thereto is pulled by pultrusion into mold 8. Flexible mold 8 may be any shape, but is preferably a tube of any given length. Flexible mold 8 may be comprised of any flexible material such as, but not limited to, rubber, plastic, organic membranes, or flexible metal tubing (e.g., copper). In one embodiment of the present invention, a silicon rubber flexible mold is used. As they are pulled into mold 8, fibers 1 saturated with liquid resin 6 takes the shape of mold 8, which in this case is a tube. Mold 8 can then be manipulated into any desired shape or form. Once mold 8 is manipulated into a desired shape, it is held or clamped until the resin cures to hardness.
As shown in FIG. 4 and FIG. 5, flexible mold 8 may be held securely in place by anchor supports 9 and 10. These anchor supports may be curved clamps capable of placing pressure on mold 8 and keeping it in place. Any available method of securing mold 8 may be used to keep the mold in place as fiber bundle 1 is pultruded therein.
After the resin saturated fibers cure to hardness, mold 8 is then removed by chemical or mechanical means. Mechanically, mold 8 may be cut and stripped away or chiseled or flaked away. Chemically, solvents such as N-N-dimethylformamide or trichloroethylene may be used to remove mold 8. After mold 8 is removed, one is left with a fiber reinforced resin composite in the shape formed with mold 8.
This method of pultrusion into a flexible mold is not known in the art. It is a superior way, however, in which to manipulate prepreg, and eliminates tackiness and mold release problems when formed into configurations such as automotive roll bars, bicycle frames, coils, special shape bends for reinforcing bars, or any other curved shape. The usefulness of this novel method is evident to those in the trade, and allows unlimited manual usage which is a departure from regular prepreg tapes or sheets and eliminates the problem of resin clean-up. Resin clean-up has been a major problem of the composite industry for years. This new novel method permits freedom of manipulation in fabrication, and avoids contamination of personnel, without the use of gloves. Additionally, it is to be understood that the resulting items utilizing this process may be round, square, or any shape which is available in a flexible mold or tubing of rubber, plastic, organic membranes or any flexible material.
The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that the invention is capable of other and different embodiments. As is readily apparent to those skilled in the art, variations and modifications can be affected within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only, and do not in any way limit the invention, which is defined only by the claims.
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A method of pultrusion is provided that includes the steps of saturating a bundle of fibers in a curable resin, pulling the saturated fibers (also known as "prepreg") into a flexible mold, manipulating the mold (with the saturated fibers therein) into a given shape or form, allowing the saturated fibers to cure or harden, and then removing the flexible mold by mechanical or chemical means. This novel method permits one to mold prepreg into any given shape prior to hardening, not limited by the shape of a given mold or die.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Non-Provisional Application of co-pending U.S. Provisional Application No. 60/863,240, filed Oct. 27, 2006, which is incorporated herein by reference.
FIELD OF THE INVENTION AND BACKGROUND
[0002] The invention relates to the field of Chemical Mechanical Planarization (CMP).
[0003] Other than global planarization and high polish rate, the Chemical Mechanical Planarization (CMP) process should also achieve high material selectivity (high polishing rate of one material compared to the other), high quality surface finish, which is devoid of scratches, pattern related defects, pits and particle contamination.
[0004] The CMP process synergistically combines both tribological and chemical effects to planarize metal like copper, tungsten and insulating materials such as silica and polymers. FIG. 1 shows the schematic diagram for the CMP process. The polishing process involves active abrasion of the wafer surfaces using abrasive particles present in the slurry and active mechanical component, provided by the polishing pad. Such an abrasion results in surface scratches on the surface of the wafer. The scratches result in formation of puddles in further layers causing an electrical short circuit. As the industry progresses into the 45 nm node and beyond, the requirement for post CMP surface quality and defects becomes more critical. Oxide CMP is conducted during shallow trench isolation in logic device fabrication and also in many other novel applications. Defects during CMP hamper the device yield and reducing the defects is thus highly important. These defects result in nullifying the advantages of using CMP as a global planarization technique.
[0005] CMP defects arise due to contamination issues from slurry chemicals, particle contamination (residue) from abrasive, scratches during polishing due to agglomerated abrasive particles, pattern related defects like dishing and erosion, delamination and dielectric crushing due to mechanical damage of dielectrics. Therefore, what is needed is a novel slurry for use with the CMP process containing soft particles that do not cause as aggressive scratching, leave particle residue, or apply high mechanical stress.
[0006] Composite materials containing polymeric and inorganic units have been attracting considerable attention in the areas of medicine, paint, and specialty chemical industries. For example, polymer-inorganic oxide composites are promising candidates as slurries for chemical mechanical polishing while zinc oxide particles coated with fluoropolymers are an important constituent of cosmetic foundation creams. Composites of poly(vinyl alcohol)-TiO2 are being examined as a cheap replacement for nafion-platinum membranes for application in alkaline direct methanol fuel cells.
[0007] To obtain polymer-inorganic microcomposites, a few researchers have explored using supercritical fluids as a means to incorporate insoluble inorganic nanoparticles into the organic network. One drawback lies in that these nanoparticles often aggregate within the polymer thereby reducing the effective surface area. Other approaches have involved using polymer synthesized by emulsion polymerization to encapsulate inorganic or metallic nanoparticles. However the organic-aqueous interface required for polymerization frequently requires toxic organic solvents, surfactants, and stabilizers that can be difficult to remove and can create environmental problems. Therefore, approaches using polymers that do not require organic solvents or stabilizers and that are easy to load with nanoparticles to create composites can be quite useful.
[0008] In recent years the fabrication of stimuli responsive polymeric materials based on N-isopropylacrylamide has generated much interest due to its ease of synthesis in aqueous media and their technological application. These stimuli responsive polymers can respond in shape and size to external stimuli like temperature, pH, ionic strength, etc. PNIPAM is a nonionic polymer typically, prepared by free radical precipitation polymerization. In aqueous solutions, PNIPAM displays a reversible phase transition behavior around an easily accessible temperature of 32° C. As a result, PNIPAM has become the most widely studied water based temperature sensitive polymer. Since the first synthesis of poly(N-isopropylacrylamide) (PNIPAM) microgels by Pelton in 1986, cross-linked, microspherical particles or “microgels” of PNIPAM have been of particular interest. These microgels are typically achieved using a divinyl compound to cross-link the polymer chains into a porous network.
SUMMARY OF INVENTION
[0009] The invention includes novel abrasive particles to carry out CMP at relatively low down force (low mechanical stress) yet achieve desirable removal rates and superior post CMP surface quality (reduced scratches). Two classes of particles—hybrid PNIPAM-polysiloxane particles ( FIG. 2 ) and composite particles based on the hybrid polysiloxane network with embedded nanoparticles ( FIG. 3 ) of an inorganic metal-oxide (MO x ) are used. The organic-inorganic composition of the polymer network is controlled by changing the time for condensation and hydrolysis of the siloxane monomer during synthesis. Characterization of these particles was performed by FTIR spectroscopy, dynamic light scattering, and electron microscopy (TEM/SEM). Tribological characteristics during polishing employing these novel particles were studied on a bench-top CMP tester. Surface roughness and defectivity are estimated using Atomic Force Microscopy (AFM).
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
[0011] FIG. 1 . Schematic diagram of the CMP polishing process
[0012] FIG. 2 . Schematic diagram for synthesis of hybrid PNIPAM-polysiloxane particles in two sizes (large and small) and the condensation of siloxane to make a core-shell PNIPAM-silica particle.
[0013] FIG. 3 . Schematic diagram for the preparation of a composite particles made by mixing ceria (CeO 2 ) nanoparticles with the hybrid PNIPAM-polysiloxane hybrid particles that include intepentrating chains of poly(acrylic acid).
[0014] FIG. 4 . Typical experimental conditions for slurry testing
[0015] FIG. 5 . Particle size of the large PNIPAM-polysiloxane hybrid particles as a function of temperature measured using DLS.
[0016] FIG. 6 . Particle size of the small PNIPAM-polysiloxane hybrid particles as a function of temperature measured using DLS.
[0017] FIG. 7 . Particle size of the core-shell PNIPAM-silica particles as a function of temperature measured using DLS.
[0018] FIG. 8 . Graph of size distribution of the large and the small PNIPAM-polysiloxane hybrid particles and the core-shell PNIPAM-silica particles at high temperature (collapsed state).
[0019] FIG. 9 . TEM image of small PNIPAM-polysiloxane hybrid particles.
[0020] FIG. 10 . TEM image of large PNIPAM-polysiloxane hybrid particles.
[0021] FIG. 11 . TEM image of the core-shell PNIPAM-silica particles.
[0022] FIG. 12 . FTIR spectra of small and large PNIPAM-polysiloxane hybrid particles compared to only PNIPAM microgels.
[0023] FIG. 13 . Details of the slurry samples made out of large PNIPAM-polysiloxane hybrid particles at two temperatures and slurries of commercial silica particles used for comparison.
[0024] FIG. 14 . Removal rate measurements during CMP of thermal oxide wafers using large PNIPAM-polysiloxane hybrid particles at two temperatures compared to commercial silica particles.
[0025] FIG. 15 . COF data measured in-situ during CMP of thermal oxide wafers using large PNIPAM-polysiloxane hybrid particles at two temperatures compared to commercial silica particles.
[0026] FIG. 16 . FTIR spectroscopy on thermal oxide wafer surface before and after CMP with large PNIPAM-polysiloxane hybrid particles at two temperatures particles and the silica particles.
[0027] FIG. 17 . Table showing surface roughness after CMP using large PNIPAM-polysiloxane hybrid particles at two temperatures compared to commercial silica particles.
[0028] FIG. 18 . TEM of PNIPAM-polysiloxane-Ceria composite particles. Black dots indicate nanoparticles of ceria evenly dispersed within the microgel at approximately 50 weight % loading.
[0029] FIG. 19 . TEM of PNIPAM-polysiloxane-Ceria composite particles. Black dots indicate nanoparticles of ceria evenly dispersed within the microgel at approximately 10 weight % loading.
[0030] FIG. 20 . Graph showing the coefficient of friction during CMP at pH of 12 using large PNIPAM-polysiloxane hybrid particles, small PNIPAM-polysiloxane hybrid particles, and composite PNIPAM-polysiloxane-Ceria particles compared to the commercial ceria particles.
[0031] FIG. 21 . Graph showing removal amounts of SiO2 using transmission FTIR spectra of SiO2 wafers before and after polishing at pH12 using composite PNIPAM-polysiloxane-Ceria particles and commercial ceria particles.
[0032] FIG. 22 . Graph showing the coefficient of friction during CMP at pH of 5 using a slurry with 0.25 weight % composite PNIPAM-polysiloxane-Ceria particles compared to polising with 0.25 wt % and 0.5 wt % commercial ceria particles.
[0033] FIG. 23 . Graph showing removal rates of SiO2 after polishing at pH of 5 using a slurry with 0.25 weight % composite PNIPAM-polysiloxane-Ceria particles compared to polising with 0.25 wt % and 0.5 wt % commercial ceria particles.
[0034] FIG. 24 . AFM image showing topography of an unpolished wafer.
[0035] FIG. 25 . AFM image showing topography of a wafer after polishing with commercial silica particles at pH12.
[0036] FIG. 26 . AFM image showing topography of a wafer after polishing with slurry containing 0.25 wt % of commercial ceria particles at pH5.
[0037] FIG. 27 . AFM image showing topography of a wafer after polishing with slurry containing 0.50 wt % of commercial ceria particles at pH5.
[0038] FIG. 28 . AFM image showing topography of a wafer after polishing with slurry containing hybrid PNIPAM-polysiloxane particles at pH12.
[0039] FIG. 29 . AFM image showing topography of a wafer after polishing with slurry containing composite PNIPAM-polysiloxane-Ceria particles at pH5.
[0040] FIG. 30 . Optical microscopy image showing absence of scratches on a wafer after polishing with slurry containing composite PNIPAM-polysiloxane-Ceria particles at pH5.
[0041] FIG. 31 . Optical microscopy image showing scratches on a wafer after polishing with slurry containing 0.25 wt % commercial ceria particles at pH5.
[0042] FIG. 32 . Optical microscopy image showing scratches on a wafer after polishing with slurry containing 0.50 wt % commercial ceria particles at pH5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] The invention includes slurries using novel soft particles that do not cause as aggressive scratching, leave particle residue, or apply high mechanical stress. The abrasives in the slurry are as composite materials. There has been past research on use of mixed abrasives or just polymer particles and use of abrasive free slurries to reduce scratches during CMP. Minimal success has been achieved, however, in optimizing both removal rates and reducing surface scratches and particle residue at the same time.
[0044] The generation of surface scratches depends on a wide variety of factors such as the process conditions, characteristics of the abrasive particles, their content in the slurry, hardness of the pad, chemistry of the slurry etc. Of particular interest in the art are the characteristics of the abrasive particles. Abrasive particles at times agglomerate in the slurry and the effective size of the particles can be much higher than the specification of the slurry. Such agglomerated particles cause deep scratches in the surface and result defects that cannot be removed by any other post processing techniques.
[0045] Commonly used ceramic abrasive particles such as ceria are much harder than the low dielectric constant materials and copper. These particles can easily scratch the surface and if agglomerated can result in permanent scratch defects. Thus, the inherent nature of the particle plays a significant role.
[0046] Researchers in the recent past have studied mixed or modified abrasive particles in order to reduce defects during CMP. These studies mostly use abrasives of different inorganic oxides and of different sizes or use micelles etc. The surface scratches and particle residue both have not been addressed using those methods as the inherent material characteristics of the abrasive particle that meets the wafer surface is still hard and has the same surface properties. Here, novel abrasives based on composite and hybrid particles are being developed that do not scratch the soft interconnect materials as deeply as the hard ceramic particles. The design of surface functionalized particles is targeted towards achieving low particle residue after CMP so that post CMP clean becomes simpler without using concentrated chemical solutions thus facilitating environmentally benign CMP process.
Synthesis of Hybrid Microgel Particles of PNIPAM-Polysiloxane
[0047] The composite and hybrid particles of the present invention are useful in slurries for chemical mechanical planarization (CMP) and reduce scratches and particle embodiment into the silicon oxide wafer surface and could later be extended to wafers used for shallow trench isolation. Hybrid (poly(n-isopropylacrylamide)-siloxane (PNIPAM-polysiloxane) particles were synthesized by precipitation polymerization ( FIG. 2 ). The particles were hybrid in nature due to the use of a siloxane comonomer during the polymerization that provided sites for further condensation of inorganic silica (silicon dioxide).
[0048] The silica fragments were incorporated for hard abrasion while the polymer was used to provide a softer, smoother particle that would prevent surface defects, typically seen in CMP with slurries comprising of only silica nanoparticles. These particles can be made in varying size such as large particles roughly 300 nm in diameter and small particles approximately 50 nm in diameter as seen in FIG. 2 . The size of the hybrid particles transitioned with temperature and increase at lower temperatures as seen in the dynamic light scattering (DLS) plot in FIGS. 5 , 6 , and 7 .
[0049] The hybrid microgels are formed by the co-polymerization of the NIPAM monomer with siloxane monomer such as 3-(trimethoxysilyl)-propyl methacrylate (MPS). Examining the Fourier transform infrared (FTIR) spectrum in FIG. 12 revealed the emergence of a new peak in the hybrid microgels as compared to the PNIPAM microgels. The peak at 1725 cm −1 is indicative of the presence of the copolymer containing silica. The more MPS added as a co-monomer, the greater the silica content in the microgel and the harder the particle.
[0050] With the goal of developing novel slurry for CMP applications, the hybrid PNIPAM-polysiloxane particles used with the current invention are synthesized using precipitation polymerization method. Core-shell polymer particles can be made by condenstation of the silica fragments as seen in FIG. 2 and FIG. 11 where a silica core is surface functionalized. Once the hybrid particles were synthesized, they are dispersed in water; the solution was made to have a pH of 12 using 2 weight percent KOH solution. Commercial silica particles of same weight percentage were used to make slurries to be used to compare with the hybrid particles.
[0051] The slurries were then employed to polish thermally grown silicon dioxide wafers on a bench top CMP tester. The bench top tester provides real-time measurements of the following tibological parameters of the polishing: a) force sensor provides measurement of real friction coefficient by monitoring simultaneously and independently a horizontal friction force or torque and a vertical normal load (above the wafer and beneath the pad); b) high-frequency acoustic emission (AE) sensors provide very high sensitivity to tiny local asperities, debris, micro-cracks, etc. Their frequency allows for detection of much smaller material removal than that observed with commercial AE sensors and it allows monitoring CMP process within the same layer and from layer to layer. The testing of the slurry samples made out of novel hybrid particles and pure silica particles were carried out at the process conditions summarized in FIG. 3 .
[0052] To reduce the scratches on the wafer surface post CMP process and to reduce the post cleaning issues, pure silica particles were replaced by hybrid particles made out of polymer, functionalized with inorganic oxide (i.e. silica and siloxane). The incorporation of functional groups into polymer latexes to form new hybrid materials represents an emerging discipline for the synthesis of novel materials with diverse architectures. Hybrid materials with a controllable surface hardness and chemical nature will provide significantly improved surface finish on the wafer surface after oxide CMP by reducing surface scratches and particle residue.
[0053] Polymer-silica particles have shown fewer surface defects as compared with commercial slurries but appear to aggregate at the water-air interphase with poor dispersion properties. To enhance the dispersion properties of the hybrid microgel, the inventors incorporated a co-monomer, the hydrophilic nature of which provides the necessary repulsion between the particles when dispersed in water and also results in the easy removal from the wafer surface after CMP process. The silanol functional groups of an illustrative embodiment were introduced using 3-(trimethoxysilyl)propyl methacrylate (MPS) as the other co-monomer.
[0054] FIG. 8 shows the distribution of large and small hybrid particles as well as the core-shell PNIPAM-silica particles. The polydispersivity in size is low. The details of the slurry samples made out of the large PNIPAM-polysiloxane hybrid particles have been tabulated in FIG. 13 . All the slurries were formulated to have equal amount of weight percentage of abrasive particles. Two temperatures were used for the hybrid particles that affects the size of the hybrid particles.
[0055] CMP of 2″ thermal oxide wafers was carried out on the polisher using the above mentioned slurries containing 2 wt % KOH maintaining the slurries at a pH of 12.55 approximately. The removal rate measurements as presented in FIG. 14 were obtained by using a Rudolph AutoEL III ellipsometer. The coefficient of friction data measured insitu by the polisher is presented in FIG. 15 . From the removal rate data, it can be noticed that the hybrid particles performed similar to the silica particles. Friction data suggested that the hybrid particles demonstrated better frictional characteristics as compared to the 50 nm and 150 nm silica particles. This indicates that the hybrid particles perform much better than the traditional silica particles resulting in similar removal rate and having less friction at the interface. The hybrid particles at higher temperature and smaller size resulted in lower coefficient of friction and slightly higher removal rate as compared to the swollen hybrid particles at low temperatures. This result could be due to the increased interaction of the silica content of abrasive with the oxide film on the wafer surface when the hybrid particle shrinks with temperature.
[0056] The thermal oxide wafer surface was characterized before and after CMP using Fourier Transform Infrared (FTIR) Spectroscopy to ensure any deposition of the polymer material onto the wafer surface during polishing. From the FTIR spectrum (see FIG. 16 ), it can be seen that polishing with the hybrid or silica particles did not result in any hydrocarbon contamination on the surface of the wafer as no absorbance is seen in the region near 3000 cm −1 .
[0057] Surface roughness imaging using Atomic Force Microscopy (AFM) was conducted to probe the surface quality and roughness. The numerical values of the surface roughness are presented in the FIG. 17 . From the AFM images ( FIGS. 24 , 25 , and 28 ) and the numerical data, it could be seen that the hybrid particles performed much better than the pure silica particles both in terms of achieving lower surface roughness and more importantly lowering the particle residue, which helps eliminate rigorous post CMP clean steps. Thus the developed low defect slurry also helps in achieving environmentally benign CMP process.
[0058] Hybrid particles based on a polymer modified with inorganic component were successfully synthesized and used for low defect CMP slurry applications. The hybrid particles resulted in similar oxide removal rate as that of conventional silica particles but revealed a lower coefficient of friction. The novel particles resulted in superior surface quality and lower particle residue as compared to conventional silica particles. Improved surface finish, lower COF without compromising removal rate make these particles potential candidates for next generation stringent polishing requirements.
[0000] Synthesis of Composite Particles Based on Combining Metal Oxide Nanoparticles with the Hybrid PNIPAM-Polysiloxane Particles
[0059] Novel composite particles were perepared by combining nanoparticles of metal oxides such as ceria (CeO 2 or cerium dioxide) with the hybrid PNIPAM-polysiloxane particles to enhance removal rates wile maintaining superior surface finish and low coefficients of friction. The hybrid particles were modified with an interpenetrating polymer such as poly(acrylic acid) to incorporate the cera nanoparticles as seen in the schematic in FIG. 3 . The content of the ceria in the composite particles can be varied by changing the mixing ratio. TEM images seen in FIGS. 18 and 19 show that the ceria nanoparticles are evenly distributed within the particles.
[0060] Slurries were made with the composite particles containing 50 weight % ceria and used for CMP of thermal oxide wafers. All the slurries of the composites particles were formulated to have 0.50% by weight of abrasive particles in the aqueous solution. For comparison slurries of commercial ceria nanoparticles were made. A high (approximately 12) and a low (approximately 4) pH condition was used to test the effect of chemical conditions on removal rate.
[0061] Friction data seen in FIG. 20 suggested that the composite PNIPAM-polysiloxane-Ceria particles had better frictional characteristics as compared to the hybrid PNIPAM-polysiloxane particles and had comparable COF to the commercial ceria particles. The thermal oxide wafer surface was characterized before and after CMP using Fourier Transform Infrared (FTIR) Spectroscopy to assess the removal fo surface oxide. At the high pH, little removal was found as can be seen in FIG. 21 .
[0062] Enhanced removal rates were observed by controlling the pH conditions during polishing with the novel composite PNIPAM-polysiloxane-Ceria particles. For comparison, slurries with commercial ceria particles with two different weight percentages. A slurry with 0.25 wt % ceria particles was used to keep the content of ceria the same between the slurries of the composite particles and the commercial ceria particles. A slurry with 0.5 wt % ceria particles was used to keep the total particle content the same between the slurries of the composite particles and the commercial ceria particles.
[0063] The COF during the ploshing with the composite particles is comparable to the commercial ceria particles as seen in FIG. 22 . The removal rates with the composite particles are comparable to the values obtained using commercial ceria particles at the same weight percentage of ceria. The removal rates using the novel composite particles are nearly 10 times that of the removal rate obtained using the hybrid PNIPAM-polysiloxane particles.
[0064] Surface quality was measured using AFM and optical microscopy. It can be clearly seen from the AFM images in FIGS. 26 and 28 and the optical images in FIGS. 31 and 32 that polishing with the commercial ceria particles causes significant surface scratching and reduces surface quality by introducing defects. The composite particles perform much better and no scratches can be seen in AFM imaging ( FIG. 29 ) or the optical image ( FIG. 30 ). Thus the developed low defect slurry of composite particles base on combining ceria nanoparticles with the novel hybrid PNIPAM-polysiloxane particles also helps in achieving significant removal of the surface oxide wile providing superior surface finish.
Example I
[0065] N-Isopropylacrylamide (NIPAM) that was previously recrystallized in hexane, was dissolved in DI water to which a divinyl cross-linker, N,N′-Methylenebisacrylamide was added. The solution was bubbled with nitrogen gas, to displace oxygen after which the polymerization was initiated at 75° C. with the ionic initiator Potassium Persulfate. Two hours after initiation, 25 wt % (as that of the total NIPAM) of the co-monomer, 3-(Trimethoxysilyl)propyl methacrylate was added to the reaction mixture and the polymerization allowed to continue for a further 1 hr 45 mins. The product obtained was centrifuged at 7000 RPM and washed with deionized water three times to remove oilogmers, unused reactants and side products. The resulting hybrid PNIPAM-polysiloxane material was characterized using Fourier Transform Infrared (FTIR), Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM). These particles were then used for chemical planarization on CETR bench top tester.
[0066] Chemical Mechanical Polishing (CMP) of silicon dioxide wafers was performed using the slurries made with the above abrasive particles on a bench top CMP tester using an IC1000 perforated/Suba 500 polishing pad. Planarization was conducted at a typical downward pressure of 4 psi, pad rotation of 200 rpm and a slurry flow rate of 75 ml/min. The pH of the slurries was adjusted to 12. Typical conditions for the slurries are seen in FIG. 13 .
[0067] The average removal rate during is represented in FIG. 14 and the average coefficient of friction during CMP with different particles is graphically represented in FIG. 15 . The PNIPAM-polysiloxane hybrid particles resulted in the lowest coefficient of friction when compared to slurries with only silica particles, which translates to lower shear force on the wafer surface during polishing. This makes the PNIPAM-polysiloxane hybrid particle a potential candidate for next generation CMP slurries.
[0068] From the FTIR spectra shown in FIG. 16 , no organic residue from the polymer was found on the surface of the polished wafer. Polishing with silica alone yields many scratches on the wafersurface, which can be detrimental to the process yield of the fabricated devices (integrated chips). The tabulated values in FIG. 17 showed that the surface roughness after polishing with the hybrid particles is significantly lower and the surface is smooth. Thus, the PNIPAM-polysilxane particles present an advantage over the conventional particles as they resulted in a lower coefficient of friction during CMP and better post CMP surface quality.
[0069] In another embodiment, The invention enhances the polymer-inorganic particles to achieve high removal rates and to reduce the size of the particles. Two alternate types of polishing particles were synthesized to help reduce scratches, dishing and other non-uniformities during CMP. The alternative polishing particles include: (a) approximately 500 nm core-shell PNIPAM-silica particle; (b) approximately 50 nm PNIPAM-polysiloxane yrbid particle.
500 nm Core-Shell PNIPAM-Silica Particle
[0070] The core-shell particle of PNIPAM and silica was synthesized by precipitation polymerization, using a procedure very similar to the hybrid PNIPAM-polysiloxane described previously. By extending the reaction time, the condensation of the siloxane groups into condensed silica is promoted with a shell of soft polymer. This soft polymeric shell of predominately PNIPAM, has the huge advantage of reducing friction at the interface between the polishing pad, slurry and oxide wafer during polishing. The morphology of these particles is clearly depicted in the TEM image shown in FIG. 11 , where the inner dark core consists of the condensed silica, while the lighter outer region consists of a polymeric shell.
[0071] Probing these samples with DLS characterization reveals that they are still responsive with temperature. As shown in FIG. 7 , when swollen below the transition temperature, the coreshell microgels are roughly 600 nm in diameter. Crossing the transition temperature, the responsive PNIPAM shell collapses onto the silica core, with the overall particle measuring about 480 nm in diameter. These core-shell particles did not transition to 300 nm like the hybrid PNIPAM-polysiloxane particles due to the dense non-responsive silica core. Careful control of the monomer ratios, the thickness of the polymer shell can be tailored. Also, the hardness of the particle can also be controlled by varying the temperature, thereby creating a softer abrasive particle around 20° C. and a harder abrasive particle at 40° C.
50 nm PNIPAM-Polysiloxane Fine Particles
[0072] A second type of abrasive particle that was synthesized was 50 nm PNIPAM-polysiloxane hybrid particle. These particles have a similar morphology to the hybrid PNIPAM-polysiloxane particles, but are roughly 10% of the diameter when collapsed. This in turn leads to a dramatic increase in the surface area that is available for abrasion of the wafer surface. These particles are also of similar dimensions to fused silica that are used in conventional, commercial slurries for CMP.
[0073] The 50 nm PNIPAM-polysiloxane particles were prepared using a procedure similar to the larger hybrid particles with one major difference. Roughly 10 wt % (as that of the total NIPAM) of a detergent, sodium dodecyl sulfate (SDS), was added to the initial NIPAM solution in DI water.
[0074] Due to the poor resolution of the TEM at nanometer dimensions, the silica fragments are not clearly visible in FIG. 9 . The inventors can infer that the particles are spherical, unaggregated and quite monodisperse. To confirm the presence of siloxane, the inventors have focused on FTIR. The spectrum of the 50 nm PNIPAM-polysiloxane and the hybrid PNIPAM-polysiloxane overlap nearly identically ( FIG. 12 ), suggesting a similar incorporation of the siloxane into the 50 nm PNIPAM-Silica particles.
[0075] Using FTIR, the presence of the peak at 1725 cm −1 in FIG. 12 can be seen, inferring the presence of siloxane within the microgels. The strength of the shoulder peak at 1725 cm −1 is similar, resulting in equal incorporation of inorganic within both microgels.
[0076] The responsive behavior of the 50 nm PNIPAM-polysiloxane particles is seen in FIG. 6 , where the zone of transition is consistent with the other microgels. These particles transition from roughly 100 nm to about 50 nm.
Example II
Composite PNIPAM-Polysiloxane-Ceria Particle
[0077] Another type of particle developed was a composite of PNIPAM-polysiloxane-Ceria. Ceria (CeO2) has been known to yield excellent removal rates for silicon oxide during chemical mechanical planarization. Nanoparticles of ceria were evenly dispersed within the microgel framework as shown in the TEM image in FIGS. 18 and 19 . The ceria was incorporated in to the microgels using interpenetrating chains of polyacrylic acid (PAA) that are known to functionalize the inorganic oxide surfaces (see our publication in Journal of Colloid and Interface Science)
[0078] Interpenetrating chains of PAA were incorporated in the hybrid PNIPAM-polysiloxane particles by mixing poly(acrylic acid) sodium salt (Mw ˜15,000 g/mol) in the initial reaction mixture of NIPAM in DI water in ratio of 2 to 1 by weight (as to the total NIPAM content). After purification, a solution of the hybrid particles was mixed with a suspension of nanoparticles of CeO2 (Sigma-Aldrich) suspended in deionized water with the pH adjusted to 5. The loading of the Ceria could be changed by varying the mixing ratio. FIG. 18 shows a loading of 50 wt % of ceria in each hybrid particle and FIG. 19 shows a loading of 10 wt %.
[0079] Chemical Mechanical Polishing (CMP) of silicon dioxide wafers was performed using the slurries made with the above abrasive particles on a bench top CMP tester using an IC1000 perforated/Suba 500 polishing pad. Planarization was conducted at a typical downward pressure of 7 psi, pad rotation of 150 rpm and a slurry flow rate of 75 ml/min.
[0080] The pH of the slurries was adjusted to 12. A higher downward pressure was applied to investigate if a higher removal rate than the previous experiments could be achieved using these abrasive particles without adversely affecting the polishing surface. The average coefficient of friction during CMP with different particles is graphically represented in FIG. 20 . The PNIPAM-polysiloxane-ceria resulted in the lowest coefficient of friction of all the particle types, which translates to lower shear force on the wafer surface during polishing. This makes the composite PNIPAM-polysiloxane-Ceria particle a potential candidate for next generation CMP slurries.
[0081] From the FTIR spectra shown in FIG. 21 , the decrease in the Si—O—Si peak at 1075 cm-1 is due to the removal of the silicon oxide. Removal rates need to be quantified but the FTIR shows that the removal rate is low at pH12 for both ceria and composite slurries.
[0082] In order to optimize the polishing performance further, the pH was changed to 5 to enhance removal rates. FIG. 22 shows the COF during polishing and FIG. 23 shows the removal rate. It is evident that removal rates are higher for the ceria particles even when the weight percent of the ceria is comparable to that of the PNIPAM-polysiloxane-ceria slurry. However, now only three minutes of polishing with the novel particles gives substantially more removal of oxide than the case of pH 12 as well as the case of hybrid particles alone.
[0083] However, it is important to note that the surface scratching for the ceria particles becomes severe now, which is evident in the distortion of the AFM and optical images of the polished surfaces. Polishing with ceria yields many scratches on the wafer surface, which can be detrimental to the process yield of the fabricated devices (integrated chips). In comparison, the novel PNIPAM-polysiloxane-Ceria particles present an advantage over the conventional particles as they resulted in a no visible scratches and better post CMP surface quality with fewer defects.
Example III
[0084] In another embodiment, composites of the polymer microgels were made with nanoparticles of titania (TiO2) to illustrate that the novel particles can be extended to other metal oxide materials.
[0085] Interpenetrating microgels were formed by the surfactant free precipitation polymerization of NIPAM (1 g) in an aqueous solution (200 ml) containing poly(acrylic acid) sodium salt (1.5 g, Mw >>15,000 g/mol). MBAA (0.04 g) was used as the cross-linker and KPS (0.02 g) served as the initiator. Following purging with N2, the reaction mixture was heated in an oil bath to 75+C and the initiator was added. After polymerization for 5 h, the product was cleaned by washing and centrifuging three times.
Preparation of Interpenetrating Microgel-TiO2 Composite
[0086] Nanoparticles of TiO2 powder (commercially available or laboratory synthesized ultrafine particles) were suspended in deionized water with the pH adjusted to 1.5 using 37% v/v HCl to maintain a positive charge on the particle surface. Large aggregates in the suspension were removed by centrifugation so as to obtain a more homogeneous dispersion of TiO2. An interpenetrating microgel solution was mixed with the TiO2 suspension in a desired loading ratio and the pH was adjusted to >>6. The composite that formed settled to the bottom and the supernatant was removed. The composite was cleaned by washing three times with deionized water.
[0087] Composites of IP-microgels and TiO2 were examined using TEM to visually determine the extent of TiO2 loading. An assay of the TiO2 content in the composite was also done using either absorbance measurements using a spectrophotometer or thermo-gravimetric measurements.
SUMMARY
[0088] In summary, hybrid particles consisting of a polymer modified with inorganic components were successfully synthesized and used for low defect oxide CMP slurry applications. Removal of the oxide from the wafer surface was determined, the coefficient of fricting during polishing was measured, and the surface quality was characterized. These hybrid particles produced a superior surface quality after planarization with very few surface scratches and no particle residue on the oxide wafer surface thereby making these particles potential candidates for next generation stringent polishing requirements.
[0089] The hybrid particles were further modified in size and core-shell morphology and also by making composites with nanoparticles of metal oxides such as CeO2 and TiO2. CMP with the composite particles containing ceria showed removal rates and coefficient of friction measurements comparable to slurries with same content of only ceria particles. However, slurries with conventional ceria particles resulted in severe scratches on the wafer surface. These scratches can result in the formation of puddles in further deposited layers that leads to electrical short circuits. Conversely, slurries consisting of the composites resulted in few surface defects and thus can be employed for the polishing of 45 nm node devices and shallow trench isolation in next generation logic device fabrication. Fewer surface defects and particle residue can also aid in the elimination of rigorous post CMP cleaning stages that consequently will help in achieving environmentally benign CMP process.
[0090] Composite particles with controlled softness/hardness can be potentially beneficial and can be successfully implemented for polishing in the final stage of CMP process where only moderate amounts of material needs to be removed but superior surface quality is required.
[0091] The approach of making composites using hybrid polymer particles and interopenetrating microgels described in herein is simple and can be extended to other inorganic nanoparticles of alumina, zinc oxide, and iron oxide that have functional characteristics for a variety of applications such as fuel cell catalysis or chemical mechanical polishing.
[0092] It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0093] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. Now that the invention has been described,
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Organic-inorganic composites were prepared as colloidal particles of a cross-linked, thermally responsive polymer. Hybrid PNIPAM-polysiloxane particles and composite polymeric particles with embedded nanoparticles of an inorganic metal-oxide (MO x ) such as CeO2 and TiO2 were formed. To promote the incorporation of unaggregated nanoparticles, temperature responsive microspherical gels (microgels) of N-isopropylacrylamide (NIPAM) with interpenetrating (IP) linear chains of poly(acrylic acid) (PAA) were used. The organic-inorganic composition of the hybrid polymer network was controlled by changing the time for condensation and hydrolysis of the siloxane monomer during synthesis. Experimental results indicated that the planarization of silicon oxide wafers using these hybrid particles and composites exhibited lower topographical variations and surface roughness as compared to slurries consisting of only silica or ceria nanoparticles while achieving similar removal rates and better or similar frictional characteristics.
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BACKGROUND OF THE INVENTION
This invention relates to pneumatic pump actuating mechanism, and, particularly, to the use of the aforesaid mechanisms with a sewing machine motor in threading the needle in a sewing machine.
Threading the sewing needle in a sewing machine must be performed periodically during the sewing operation. This being a very tedious task, various devices have been provided to assist the operator, which include pneumatic threading assists. In the past, the air pressure, or vacuum, used with these devices was supplied either external to the sewing machine or by a self-contained electric pump housed within or on the sewing machine frame. In either case, a motor separate from the sewing machine motor is required to operate the pump. Since needle threading is necessarily performed while the stitch forming instrumentalities are stationary, there exists a needless motor redundancy which increase the expense and the probability of failure in providing the pneumatic needle threading assist feature.
SUMMARY OF THE INVENTION
The object of this invention is to provide a mechanism which allows a mechanical pneumatic pump to be driven by the sewing machine motor while the operation of the stitch forming instrumentalities is suspended. This object is achieved by using a first, single direction, overrunning clutch between the motor and the sewing machine drive and a second, single direction, overrunning clutch oppositely arranged between the motor and a pump linkage. An electrical switch is used to reverse the electrical polarity on the motor causing the motor to run in a reverse direction. This effectively causes the first clutch to disengage the sewing machine drive, suspending the operation of the stitch forming instrumentalities, and the second clutch to engage the pump linkage to the motor thereby allowing the sewing machine motor to operate the pneumatic pump.
DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in mind as will hereinafter appear, the invention will be described with reference to the drawings of the preferred embodiment in which:
FIG. 1 is a front elevational view of a sewing machine, partially in section, showing the invention incorporated therein;
FIG. 2 is an exploded perspective view of the sewing machine motor armature with the invention installed thereon;
FIG. 3A is a partial cross-sectional view, taken along the line 3--3 of FIG. 1, showing the relative movement of the pump clutch with respect to the motor shaft;
FIG. 3B is a partial cross-sectional view, as in FIG. 3A, showing the motor shaft rotating oppositely;
FIG. 4A is a partial cross-sectional view, taken along the line 4--4 of FIG. 1, showing the relatively movement of the main drive clutch with respect to the motor shaft;
FIG. 4B is a partial cross-sectional view, as in FIG. 4A, showing the motor shaft rotating oppositely; and
FIG. 5 is a schematic drawing of the sewing machine motor speed control circuit having a reversing feature built therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is illustrated a sewing machine 10 having a bed 12, a hollow standard 14 extending upwardly from the bed 12 and a bracket arm 16 attached to the standard 14 and overhanging the bed 12. The bracket arm 16 terminates in a sewing head 18 which carries a downwardly biased presser bar 20, having a presser foot 22 attached to an end thereof. A needle bar 24 is arranged within the head 18 for reciprocatory motion and has a sewing needle 26 attached to one end thereof. A pneumatic needle threading assist 28 is shown in threading engagement with the sewing needle 26. The threading assist 28 may be constructed in accordance with that disclosed in the U.S. Pat. No. 3,599,587, Aug. 17, 1971 of R. G. Greulich to which reference may be had. An air tube 30 is attached to the needle threading assist 28 and extends through the bracket arm 16 terminating at a pneumatic pump 32 secured in the standard 14. A main drive shaft 34 is rotatably carried in the bracket arm 16 for imparting the reciprocatory motion to the needle bar 24. The main drive shaft 34 terminates in a hand wheel 36 having a pulley 38 formed therein.
A motor 40 is provided for driving the sewing machine main drive shaft 34 and the pneumatic pump 32. As shown in FIGS. 2 and 5, the motor 40 includes an armature 41 having electrical windings 42 and 43 wound on a shaft 46 having a first end 48 protruding from one end of the motor 40 and a second end 50 protruding from the opposite end of the motor 40. The first end 48 of the shaft 46 has a first overriding clutch 52 arranged thereon. The clutch 52, which, for example, may be a Roller Clutch no. RC-02 made by the Torrington Company, has an annular shape and includes a clutch element holding member 52', an outer member 52" formed with clutch element engaging ramps to which outer member drive mechanism may be mounted, and clutch elements 53. The first clutch 52 has the characteristic that when the shaft 46 is turned in a first direction as indicated by the arrow Y in FIG. 4A, the first clutch 52 engages, while, when the shaft 46 is turned oppositely in a second direction as indicated by the arrow Y in FIG. 4B, the first clutch 52 disengages, and conversely, when the shaft 46 turns in a first direction as indicated by the arrow X in FIG. 4B the clutch 52 engages. A pulley 54, having an axial bore 56 therethrough, is formed with an axial counterbore 58 at one end of the bore 56 for receiving the outer member 52" of the clutch 52 which may be secured therein by any suitable means. A pair of retainers 60 and 62 are arranged on the first end 48 of the shaft 46 on opposite sides of the clutch pulley 54 and the first clutch 52 assembly. Set screws 64 and 66 are used to fix the retainers 60 and 62, respectively, to the first end 48 of the shaft 46. A drive belt 68 drivingly engages both the pulley 54 and the main drive shaft pulley 38, described earlier.
The second end 50 of the shaft 46 is used to drive the pneumatic pump 32. For this purpose, a second overriding clutch 70 is arranged on the second end 50 of the shaft 46. The second clutch 70 is substantially similar to the first clutch 52 in that it includes a clutch element holding member 70', an outer member 70" formed with clutch element engaging ramps, and clutch elements 71 but is oppositely arranged on the shaft 46 such that when the shaft 46 turns in the first direction as indicated by the arrow X in FIG. 3B, the second clutch 70 disengages and, conversely, when the shaft 46 turns in the second direction as indicated by the arrow Y in FIG. 3A, the second clutch 70 engages. An eccentric 72 is formed with an aperture 74 therethrough within which the outer member 70" of the clutch 70, may be secured by any suitable means. The eccentric 72 has a circular raised portion 76 having a central axis parallel to and displaced from the central axis of the aperture 74. An eccentric follower link 78 is formed with a circular hole 80 therein which slidably engages the raised portion 76 of the eccentric 72. The follower link 78 is further formed with a hole 82 for drivingly attaching the follower link 78 to a drive arm 84 of the pneumatic pump 38 using a pin 86 and a retainer 88. A follower retainer 90 is arranged on the second end 50 of the shaft 46 adjacent the eccentric 72, for holding the follower link 78 on the raised portion 76 of the eccentric 72, and is fastened to the second end 50 of the shaft 46 by a set screw 92. A first retainer 94 is arranged on the second end 50 of the shaft 46 adjacent to the follower retainer 90. A second retainer 96 is arranged on the second end 50 of the shaft 46 adjacent to the eccentric 72. The retainers 94 and 96 are attached to the second end 50 of the shaft 46 by set screws 98 and 100, respectively.
FIG. 5 shows an electrical schematic diagram of the motor 40 and an electronic speed control circuit 110 for controlling the speed of the motor 40. The electronic speed control circuit 110 is substantially similar in design and operation to that described in U.S. Pat. No. 4,098,206 of Suchsland et al which is herein incorporated by reference. The motor 40 is shown as having armature windings 42 and 43 and field windings 112 and 114. A motor control module 116 contains a silicon controlled rectifier "SCR" 118 having a cathode 120, and anode 122 and a gate 124. The "SCR" cathode 120 is connected to the end of the field winding 114. A diode 126 has a cathode 128 thereof connected to the "SCR" gate 124 and an anode 130 connected to the "SCR" cathode 120. In parallel with the diode 126 and connected across the "SCR" gate 124 and the "SCR" cathode 120 is a capacitor 132.
As further shown in FIG. 5, the motor 40 and the motor control module 116 are connected to a foot controller 134 and a power source by means of a socket 140 and a mating plug 150 having terminals 141, 143, 145, 147, 149, and 151, 153, 155, 157, 159, respectively.
A first resistor 160 is shown having one end connected to the "SCR" gate 124 and the other end connected to the socket terminal 149. A second resistor 162 is shown also having one end connected to the "SCR" gate 124 and the other end connected both to the socket terminal 147 and to the junction of the field winding 112 and the armature winding 42. The free end of the field winding 112 is connected to the socket terminal 143.
A switch 170, mounted on the standard 14 is provided for energizing the sewing machine 10 and for selecting between a high and low speed range. The switch 170 has two sets of terminals 171, 172, 173, 174, and 175, 176, 177, 178 and a sliding wiper 179 for interconnecting any two adjacent terminals in each set.
The "SCR" anode 122 is connected to the switch terminal 176 by a lead wire 180. The switch terminal 177 is connected to the socket terminal 141 by a lead wire 182. Jumper wires 184 and 186 interconnect the switch terminals 173 to 177 and 176 to 178, respectively. The switch terminal 178 is also connected to a conventional sewing machine light (not shown) by lead wire 188; the return wire 190 from the light being connected to the socket terminal 143.
A potentiometer 192 is provided for adjusting the maximum attainable motor speed in the high speed range and has a resistive element 194 and a wiper 196. The resistive element 194 is connected at one end to the "SCR" anode 122 and at the other end to a resistor 198, which is, in turn, connected to the socket terminal 145. The wiper 196 is connected to the switch terminal 174 by a lead wire 200.
The foot controller 134 contains a potentiometer having a resistive element 202, connected between the plug terminals 155 and 157, and a wiper 204 connected to an on/off switch 206, which is, in turn, connected to the plug terminal 159. For providing power to the sewing machine 10, a standard 110 volt, 60 cycle plug 208 is shown connected to the plug terminals 151 and 153.
For reversing the polarity on the armature windings 42 and 43 and the field windings 112 and 114 which consequentially reverses the direction of motor shaft 46 rotation, a momentary contact switch 210, also mounted on the standard 14, is provided having terminals 211 and 212, engaged by a lever contact 213, terminals 214 and 215, engaged by a lever contact 216, and terminals 217 and 218, engaged by a lever contact 219. The armature 41 at 220 is connected to the lever contact 213 by a lead wire 222. The armature winding 42 is connected to the terminal 211 by a lead wire 224. A jumper wire 226 interconnects the terminals 211 and 215. A lead wire 228 connects the lever contact 216 with the armature 41 at 230. The armature winding 43 is connected to the terminals 214 and 212 by a lead wire 232. The terminal 218 is connected to the socket terminal 149 by a lead wire 234 and the lever contact 219 is connected to the socket terminal 145 by a lead wire 236.
In operation, the AC plug 208 is connected to a standard 110 VAC source and the switch 170 is moved from a first position thereof to a second position thereof with the wiper 179 interconnecting the terminals 172 and 173 and the terminals 176 to 177, which energizes the sewing machine 10 in the low speed range. Accordingly, the electrical power is supplied to the SCR 118 and to the resistive element 194 of the potentiometer 192, through the resistor 198 and on to the foot controller 134. By advancing the foot controller 134, the switch 206 therein is closed and electrical power is increasingly applied to the SCR gate 124 causing the SCR 118 to energize the motor 40, rotating the shaft 46 in the first direction thereof, disengaging the second clutch 70, connected to the pneumatic pump 38, and engaging the first clutch 32, thereby driving the sewing machine main drive shaft 34 (see FIGS. 3B and 4B). When the switch 170 is moved to a third position thereof, the wiper 179 interconnects the terminals 173 to 174 and the terminals 177 to 178, which allows a portion of the resistive element 194 of the potentiometer 172 to be bypassed by the wiper 196 thereof, effectively increasing the available power supplied to the SCR gate 124 thereby switching the sewing machine 10 to the high speed range.
When it is desired to thread the sewing needle 26 using the needle threading assist 28, without depressing the foot controller 134, the switch 210 is activated, moving the lever contacts 213, 216 and 219 from the terminals 211, 214 and 217, respectively, to the terminals 212, 215 and 218, respectively. This effectively reverses the polarity of the armature windings 42 and 43 and the field windings 112 and 114 causing the motor shaft 46 to turn, at a fixed speed, in the second direction thereof. It may be found preferable to set the switch 170 into the second position for slow motor speed range when threading the needle. In any event, this opposite rotation causes the first clutch 52 to disengage and the second clutch 70 to engage thereby allowing the motor 40 to drive the pneumatic pump 38 (see FIGS. 3A and 4A) to establish a vacuum in the line 30 drawing air into the needle threader assist 28. With this condition established, and the needle threading assist manually positioned opposite the needle eye as shown in FIG. 1, the flow of air into the needle threading assist will draw thread end through the needle eye whenever the thread end is placed in close proximity thereto, thus effecting the otherwise difficult task of threading the needle eye. If this threading operation is initiated when the needle eye is below the work level, the needle will first have to be elevated either manually or by operation of any conventional needle positioning circuit before the threading assist 28 is swung down into cooperative relation with the needle.
When the threading operation is completed the switch 210 may be released and the motor and pump drive will cease to be activated. The threading assist 28 may be retracted and operation of the foot controller will effect the conventional sewing machine drive as described above.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustrations only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
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A pump actuating mechanism which allows a sewing machine motor to be used for operating a pneumatic pump. The mechanism utilizes two oppositely arranged, single direction, overrunning clutches, one connected to the sewing machine drive and the other connected to a pump linkage. An electrical switch is used to reverse the direction of the motor rotation thereby disengaging the motor from the sewing machine drive and engaging the motor with the pump linkage.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a grid system for a suspended ceiling of the kind comprising mutually spaced main runners of inverted T-profile suspended by means of hangers at the web of the T-profile, the flanges of the T-profile forming support surfaces for tiles, apertures punched at regular spacing in the web of the T-profile registering transversely of the main runners, and mutually spaced cross spacers engaging the main runners and defining the spacing therebetween.
The tiles demountably supported by the grid system conceal this system, the linear joints between adjacent tiles being visible as a rectangular pattern on the lower side of the ceiling.
2. Description of the Prior Art
Grid systems of the kind referred to above are marketed by Ecophon AB, Hyllinge, Sweden, under the trade mark Focus D. The main runners in this prior art grid system are of a reliable construction and are used also in other grid systems marketed by Ecophon AB. They are manufactured in large quantities, which keeps the price of such runners at a low level. The apertures in the web of the T-profile are punched with great accuracy. The spacers comprise L-profiles forming slots in one flange thereof to receive the main runners therein. Each spacer spans the distance between two adjacent main runners only and is located in an arbitrary displaced position along the main runners. No means are provided in order to fix the spacers in the position that has been chosen.
U.S. Pat. No. 4,089,146 discloses a grid system for a suspended ceiling with asymmetric main runners comprising rather elaborate box profiles. The main runners each form a flange for supporting a tile at one edge thereof and are combined with separate cross bars supporting the tile at two other edges thereof. Spacers of V-shaped cross section are mounted on the main runners receiving the box profile in a notch in the spacer.
3. Problem Involved
Prior art grid systems of the kind referred to above do not provide the rigidity that is necessary in order to maintain by accuracy the regularity and the right-angled shape of the rectangular pattern formed by the tiles. It follows that the lines formed at the joints between adjacent tiles at the lower side of the ceiling may vary in width and linearity, and that the tiles eventually may be slightly displaced in relation to each other after mounting, which may afford to the ceiling an unpleasant appearance.
BRIEF SUMMARY OF THE INVENTION
A primary object of the invention is to overcome said problem and to provide a grid system of the kind referred to above which rigidly supports the tiles in a rectangular pattern and maintains the tiles in such pattern in order to secure a permanently attractive appearance of the ceiling.
This object is achieved by the invention which provides a grid system for a suspended ceiling comprising mutually spaced main runners of T-profile forming a web and two flanges, hangers suspending the main runners at the web of the T-profile, the flanges of the T-profile forming support surfaces for tiles, apertures punched at regular spacing in the web of the T-profile registering transversely of the main runners, mutually spaced cross spacers engaging the main runners and defining the spacing therebetween, each cross spacer comprising a channeled girder having bottom and side walls and opening upwards said channeled girder extending over several main runners along registering apertures therein and forming slots in the bottom and side walls, the web of the T-profile being received in said slots, and fastening elements fixedly connecting each girder with the runners by engaging the apertures therein.
In a preferred embodiment of the invention the fastening elements each comprise a split pin having two limbs one of which is passed through an aperture in the main raunner and engages the bottom of the channeled girder, said bottom being slightly V-shaped to form a longitudinally extending central depression, while the other limb engages the upper edge of the web of a main runner.
The stop clip preferably is T-shaped the stem of the T being constructed for insertion through the aperture with the cross bar of the T located on one side of the main runner, the stem of the T forming latching flaps for engagement with the opposite side of the main runner
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail with reference to the accompanying drawings which disclose an illustrative embodiment of the invention and wherein
FIG. 1 is a fragmentary perspective view of a suspended ceiling with a concealed supporting grid system according to the invention,
FIG. 2 is a plan view of the grid system with tiles showing the lay-out thereof,
FIG. 3 is a cross sectional view along line III—III in FIG. 2,
FIG. 4 is a cross sectional view along line IV—IV in FIG. 2,
FIG. 5 is a plan view of a stop clip, and
FIGS. 6 and 7 are a perspective views of the stop clip in FIG. 5 from opposite sides.
DETAILED DESCRIPTION OF THE INVENTION
The grid system for a suspended ceiling disclosed in the drawings comprises main runners 10 of inverted T-profile which are of a wellknown construction. Each runner is made of a strip of a metal sheet blank which is double folded to form the web 11 of the T-profile of double metal sheet layers which are bent perpendicularly outwards at opposite sides of the web to form the flanges 12 of the T-profile at one longitudinal edge of the web. The edges of the flanges 12 are folded over to form a stiffening edge bead. The web forms a stiffening hollow portion 13 along the other longitudinal edge of the web.
Vertical slots 14 , FIG. 4, are punched in the web 11 and are mutually spaced at regular intervals, defined by great accuracy, in the longitudinal direction of the runner. In the hollow portion 13 also circular apertures 15 are punched at regular intervals.
The main runners 10 extend in parallel mutually spaced in the transverse direction thereof and with the slots in register in the transverse direction of the runners. The runners are fixedly secured in this position by cross girders 16 comprising channel profiles with a bottom 17 and side walls 18 which form outwardly angled edge flanges 19 , FIG. 4, so that the cross girders are very stiff against bending. The bottom 17 is slightly V-shaped. The cross girder forms slots 20 which extend through the bottom and partly into the side walls of the cross girder and are mutually spaced at intervals which are defined by great accuracy. Each cross girder extends over several main runners and is engaged with each runner at a slot the hollow edge portion of the main runner being inserted into the slot and has tight fit therein. The slot is flared in the bottom 17 as shown at 21 in FIG. 3 in order to facilitate the insertion of the main runner into the slot. The cross girder is located along registering slots 14 in the main runners and are fixedly connected with the main runners by means of split pins 22 which are inserted at one limb 22 A thereof into a slot 14 said limb engaging the bottom 17 centrally thereof, while the other limb 22 B engages the main runner at the edge of the web 11 . Cross girders are distributed along the main runners at suitable intervals.
The grid system consisting of the main runners 10 and the cross girders 16 is suspended from the building structure by means of adjustable hangers 23 which are engaged with the main runners at the slots 14 or at the apertures 15 and are secured in the building structure in which the suspended ceiling is mounted. The ceiling is also secured to the walls of the building structure, by means of brackets 24 connected with the cross girders 16 , and brackets 25 connected with the main runners 10 .
The grid system constructed and suspended as described above provides a very sturdy and rigid support for the tiles, which affords great dimensional accuracy to the ceiling and maintains the rectangularity of the system.
The grid system described has been developed for supporting acoustic tiles 26 having a core of fiber material such as glass wool but can be used with tiles of any type. As shown in the drawings the tiles 26 has at one edge a narrow shoulder 27 and at the opposite edge a wider shoulder 27 ′ which continues into a slot 28 . At the lower side of the tile the edges are slightly chamfered at 29 . The tile is supported at the shoulder 27 on one flange 12 of a runner 10 while the other flange 12 of an adjacent runner 10 is inserted into the slot 28 . Then, the shoulder 27 ′ covers substantially totally the lower side of the flanges 12 . Adjacent tiles abut each other at the edges. The grid system is thus completely concealed by the tiles mounted in the grid system. The tiles can easily be mounted and demounted by slightly lifting the edge forming the shoulder 27 and then displacing the tile so that the flange is pushed into or out of, respectively, the slot 28 .
At the edges 30 perpendicular to the edges forming the shoulders 27 and 27 ′, respectively, adjacent tiles join each other edge to edge.
All tiles should have a modular size but at the walls it may be necessary to cut the tiles to another size as shown in FIGS. 1 and 2 at 26 ′ and 26 ″, and these tiles must have a short measure. They are supported by trim bars 31 secured to the walls of the building structure.
When the tiles have been engaged with the main runners at flanges 12 and are displaced along the runners in order to be brought into abutting relationship at the edges, the linearity of the lines defining the rectangular pattern on the lower side of the suspended ceiling by the butt joints between the edges 30 may be disturbed, when several tiles are located in a row along the main runners, due to manufacturing tolerances of the tiles or due to the fact that the tiles 26 ′ which deviate from the modular size cannot be cut to the necessary dimensions with the accuracy applied in the factory to tiles of modular size. This means that the regularity of the rectangular pattern aimed at by providing a rigid rectangular grid system as proposed according to the invention will be lost. In order to overcome this disadvantage the invention provides the stop clip 32 disclosed in FIGS. 5 to 7 in the drawings. The stop clip is made of spring steel. It is T-shaped and comprises a U-shaped stem 33 with a web 34 and limbs 35 projecting at one end of the stem beyond the web and angled in opposite directions to form flanges 36 . At the upper and lower edges of the limbs 35 flaps 37 are punched from the limbs and project on the outside thereof at acute angle towards the adjacent flanges 36 with the tips of the flaps slightly spaced from the flanges.
The stop clip as described can be placed in a main runner by inserting the stem 33 in a slot 14 where two adjacent tiles abut each other. At the insertion the flaps 37 will be resiliently depressed and then will spring back to latchingly engage behind the web of the runner so that the stop clip will be securely fastened to the runner. By inserting stop clips at suitable intervals corresponding to a desired number of tiles and particularly between the tiles 26 ′ and the adjoining tiles 26 the influence on the linearity of the lines formed at the edges running perpendicularly to the main runners 10 on the lower side of the ceiling will be eliminated or minimized. The tiles 26 ′ in a row may be disposed to close to the wall so that the gap between the tiles 26 ′ and the adjoining tiles 16 will be too wide, but the tiles 26 in the row are fixedly positioned by the clips. If the tiles 26 have a minimum tolerance, this tolerance will be equalized at each clip so that accumulation of the tolerance along the row, affording an irregular appearance to the lower face of the ceiling, will be avoided.
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A grid system for a suspended ceiling comprising mutually spaced main runners of T-profile suspended by means of hangers at the web of the T-profile, the flanges of the T-profile forming support surfaces for tiles. Apertures are punched at regular spacing in the web of the T-profile registering transversely of the main runners. Channeled girders opening upwards and extending over several main runners along registering apertures therein engage the main runners to define the spacing therebetween, the web of the T-profile being received in slots in the bottom and side walls ( 18 ) of the channeled girder. Each girder is fixedly connected with the runners by fastening elements engaging the apertures therein.
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SUMMARY OF THE INVENTION
The present invention pertains to apparatus for connecting to a wellhead structure, more specifically, an underwater wellhead. In conducting drilling and production operations, it is necessary to provide a plurality of signal communication means, such as hydraulic or electric lines, for controlling the functions of various device such as valves and the like located on and about the wellhead. For this purpose, it has become conventional to mount at least one female body on the wellhead structure. This body defines a receptacle having a number of signal communication means directed into that receptacle. The communication lines are completed by running a male body or pod into the female receptacle such that a plurality of signal communication means directed outwardly with respect to the pod mate with those of the female body. Examples of such apparatus are shown in U.S. Pat. Nos. 3,701,549, 3,840,071 and 3,820,600.
As indicated by these prior patents, the types of connections made up by such apparatus have been hydraulic, as opposed to electrical. This has been at least partially due to the fact that, through the use of proper port configuration and sealing, the hydraulic connections require less perfect alignment than would comparable electrical connections. In many instances in which electrical connections were either necessary or desirable, It has been necessary to use substantially different types of connecting structures from those typically employed in making hydraulic connections, and also to employ electrical connectors of the "hardware" type, as opposed to inductive couplers for example. See, e.g., U.S. Pat. No. 3,839,608. In other instances, it has been necessary to employ a diver to make up the electrical connections in order to ensure proper alignment.
The present invention provides a wellhead connector apparatus which allows signal communication connections to be made up automatically as one connector body is lowered into engagement with another with such precise alignment of the parts that electrical connections, such as inductive coupler elements, can be used in the same general type of apparatus used to make up hydraulic connections.
More specifically, the apparatus of the invention includes a first female body defining a first receptacle opening generally upwardly. First guide means are connected to the first female body and engagable with the wellhead structure for at least gross positioning of the first female body with respect to the wellhead structure. A second female body has a bore defining a second receptacle opening generally upwardly and downwardly, and engagable with the first female body with the receptacles in substantial coaxial alignment. Second guide means are connected to the second female body and engagable with the wellhead structure for at least gross positioning of the second female body with respect to such structure. Compensator means interconnect one of the female bodies with its respective guide means for substantial but limited relative lateral movement. Fine positioning means cooperative between the two female bodies serve to position those two bodies with their receptacles in substantial coaxial alignment, the compensator means allowing for the necessary relative movement of the female bodies to achieve such alignment as the second body is lowered into engagement with the first.
Because the second female body is typically run in with a male body or pod, the signal communication means of these two bodies may be pre-aligned upon assembly for running in. The receptacles of the two female bodies are preferably arranged in end-to-end relation, as opposed to nesting or surrounding relation. Then, as the second female body is run in with the male body, the aforementioned compensator means and fine positioning means not only position the two female bodies in substantial coaxial alignment, but also provide such alignment between the first female body and the male body via the second female body. Circumferential alignment means cooperative between the male body and each of the female bodies provide the necessary circumferential alignment so that all signal communication means in the male body are properly aligned with their mates in either the first or second female bodies.
The male body and second female body also include means for coaxially aligning the two, such as matching tapers on the receptacle of the second female body and the mating exterior surface of the male body or pod. As previously mentioned, coaxial alignment of the male body and first female body is achieved indirectly, i.e. via the second female body. There is also a slight clearance between the receptacle of the first female body and the outer surface of the male body received therein. These features cooperate to ensure that all three bodies are aligned as perfectly as if the two female bodies had been formed in one piece, but with all the advantages of dual, stacked female bodies and without the first female body interfering with proper seating of the male body in the second female body. Furthermore, if the male body is disconnected from the female bodies and raised from the underwater wellhead location, the same or another similarly tapered male body can subsequently be lowered into place, and these tapers, together with the fine positioning means cooperative between the two female bodies, will cause all three bodies to be brought into proper coaxial alignment as the male body settles into and seats on the tapered receptacle of the second female body. Again, the compensator means will provide for any necessary relative lateral movement between the female bodies during such re-alignment.
The compensator means is preferably associated with the second or upper of the two female bodies, and in preferred embodiments, provides for not only lateral but vertical movement of that body with respect to its guide means. This provides numerous advantages including compensation for thermal expansion and contraction of the various parts of the apparatus. As mentioned, the surfaces which provide for coaxial alignment of the male body and second female body are tapered surfaces, and therefore also provide for proper relative vertical positioning. The fine positioning means cooperative between the two female bodies also include tapered or partial conical surfaces so that they too provide for vertical as well as axial alignment. Thus, the vertical movement provided by the compensator means allows for the relative vertical positioning of the two female bodies and the male body to be determined soley by the two sets of matching tapered surfaces, uninhibited by the relative positions of the various guide means and/or other parts of the apparatus connected to these bodies.
As previously mentioned, one of the primary advantages of the improved alignment and positioning features of the invention is to make practical the use of inductive electric coupler means in the type of apparatus in question. Other features of the invention are associated with the coupler elements themselves and are instrumental in ensuring a proper size gap between mating coupler elements. For example, the heads of the coupler's have chamfered edges which allow the coupler cores to be placed as close as possible to their mates without interference with proper engagement of the male and female bodies.
The invention also includes an improved means for connecting the male body to the upper or second female body. More specifically, these connection means may be associated with the actuator for the latches which retain the male body in position by engagement with the first or lower female body. Thus, when the latter latches are actuated to engage the lower female body, the connection means between the male body and the upper female body are automatically disengaged.
Accordingly, it is a principal object of the present invention to provide an improved apparatus for connecting to a wellhead structure.
Another object of the present invention is to provide such an apparatus employing inductive electric coupler elements.
Still another object of the present invention is to provide improved means for relative positioning and alignment of the various connector bodies of such an apparatus.
Yet a further object of the present invention is to provide improved compensator means interconnecting a female body of such an apparatus with its respective guide means for substantial limited lateral movement.
Still other objects, features, and advantages of the present invention will be made apparent by the following detailed description of a preferred embodiment, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, partly in section and partly in elevation, of an upper female body in accord with the present invention and the associated guide means and compensator means.
FIG. 2 is a view similar to FIG. 1 showing the male body and associated apparatus assembled with the upper female body for running in.
FIG. 3 is a transverse view taken along the line 3--3 in FIG. 2.
FIG. 4 is a bottom plan view of the upper female body of FIGS. 1 and 2.
FIG. 5 is an enlarged partial sectional, partial elevational view of the male body and upper female body assembled with the lower female body.
FIG. 6 is a view similar to those of FIGS. 1 and 2 of the female bodies in place on the wellhead structure and with the male body removed.
FIG. 7 is a transverse view taken along the line 7--7 in FIG. 6.
FIG. 8 is an enlarged partial sectional, partial elevational view of the male body and upper female body in the position of FIG. 2 but at right angles thereto.
FIG. 9 is a view similar to that of FIG. 8 showing the parts assembled with the lower female body in the position of FIG. 5.
FIG. 10 is an enlarged detail vertical sectional view through one pair of inductive electric coupler elements.
FIG. 11 is an enlarged transverse view taken along the line 11--11 in FIG. 10.
DETAILED DESCRIPTION
The present invention comprises apparatus for connection to underwater wellhead structure which is best seen in FIGS. 6 and 7. The wellhead structure is conventional and is shown in those figures only partially and in simplified form. Particularly, the wellhead structure includes a central body 10 to which are connected a number of horizontal structural support members, some of which are shown at 12 and 14. Laterally spaced to one side of central body 10 and secured to structural members 12 and 14, are a pair of parallel vertical guide posts 16. It is noted that, as used herein, terms such as "vertical," "horizontal," "upper," and "lower" refer to the apparatus as shown in the drawings, which represent it in use and in an ideal situation as on a perfectly level area of the ocean floor. It should be understood that these terms are used only in a general sense and for convenience, and are not intended to limit the scope of the invention.
The connector apparatus of the invention includes three main parts, a first or lower female body 18, a second or upper female body 20, and a male body or pod 22. Various figures will be referred to herein in describing different steps in the assembly and use of the apparatus. However, it will be helpful to also refer to the enlarged views of FIGS. 5, 8 and 9 throughout the description.
The first step in assembling the apparatus of the invention on the wellhead structure is emplacement of the lower female body 18. As shown in FIG. 6, body 18 has an annular flange 42 extending radially outwardly at its lower end. Flange 42 is rigidly affixed, as by welding, bolts, or any other suitable means, to a stab base plate 24 having a wide central vertical opening 26. Structural support members 28 are rigidly affixed to stab base plate 24 and extend laterally outwardly therefrom. As used herein, terms, such as "longitudinally," "radially," "laterally," "circumferentially," etc. refer to the longitudinal axes of bodies 18, 20 and 22, unless the context indicates another frame of reference. Structural support members 28 are interconnected by a bracing member 30 which is spaced downwardly from stab base plate 24 and further recessed as indicated at 32 along its upper surface to provide an open space beneath lower female body 18. The laterally outer extremities of structural support members 28 are fixed to respective tubular guide members. Each of these guide members has a cylindrical upper portion 34 and a frusto-conical lower portion 36, arranged with its large end lowermost.
To emplace the lower female member 18, any suitable running-in apparatus is secured to the attached parts 24, 28, 30, 34, and 36, and this assembly is lowered toward the wellhead structure. The apparatus may be roughly guided in this movement by flexible lines or the like (not shown) extending from the upper ends of vertical wellhead guide members 16 and through the tubular guide members 34, 36. As the apparatus reaches the upper ends of members 16, the frustoconical lower portions or skirts 36 of the tubular guides engage the upper ends of members 16 and guide them into the cylindrical upper portions 34. The apparatus is then further lowered with the members 16 and 34 providing proper gross positioning of the lower female body 18 with respect to the wellhead structure.
The lower female body 18 itself is generally annular in configuration, the upper portion of its central bore defining a first receptacle 38 for receipt of the lower portion of male body 22. Receptacle 38 is tapered radially inwardly and downwardly. Body 18 also has an upwardly facing annular surface 40 adjacent its upper end, surface 40 being tapered radially outwardly and downwardly for a purpose to be described more fully below.
After the lower female body 18 has been emplaced on the wellhead structure as described above, and its running-in apparatus removed, a tree with the upper female body 20 attached thereto is lowered onto the wellhead structure along with the male body 22. Male body 22 and the running-in assembly are also described more fully below. FIG. 1 shows body 20 and connected parts as they appear prior to engagement with the running-in assembly. Body 20 is generally annular, having a central vertical bore, the upper portion of which defines a second receptacle 44 for receipt of the upper portion of male body 22. The lower portion of the central bore of body 20 has a plurality of radially outwardly and downwardly tapered, and generally downwardly facing, surfaces 46 interspersed with cut-away areas 48. (See also FIG. 4.) Intermediate surfaces 46 and receptacle 44, the central bore of body 20 has a generally frustoconical relieved area 50.
Referring now also to FIG. 7, a box-like mounting structure is rigidly affixed to and extends laterally outwardly from body 20. The mounting structure includes a lower horizontal plate 52 having a central opening for receipt of a reduced diameter upper portion of body 20. Plate 52 rests on a shoulder 20a formed at the juncture of the large and small diameter portions of body 20 and is fixed thereto by screws 49. The mounting structure also includes four side walls 54 rigidly fixed to and extending upwardly from plate 52, the box-like mounting structure being open upwardly. The mounting structure 52, 54, carries a pair of upstanding positioning tubes 56. Tubes 56 have frustoconical inner surfaces, the larger ends disposed uppermost, and are aligned with vertical openings through plate 52. Tubes 56 are located approximately midway along two opposed side walls 54 of the mounting structure, and thus, on diametrically opposite sides of body 20.
Plate 52 also carries four locator elements in the form of pins 58, each mounted generally adjacent a respective one of the four corners formed by the intersection of side walls 54 of the mounting structure. Each pin 58 has an upper portion 58a which is threaded and reduced in diameter. Thus an upwardly facing shoulder 58b is formed at the juncture of said upper portion 58a and the larger diameter lower portion 58c. The upper portion 58a of each pin is inserted upwardly through a respective aperture 55 in plate 52 so that shoulder 58b abuts the underside of plate 52. The pin is then fixed in place on plate 52 by a nut 57 threaded onto portion 58a above plate 52. A washer 59 is interposed between nut 57 and plate 52.
A base member in the form of a plate 60 underlies the upper female body 20 and its mounting structure. A pair of short rims or flanges 61 extend upwardly from opposite sides of plate 60. Plate 60 has a large central bore 62 aligned with the central bore of body 20 as well as a plurality of smaller apertures 64 spaced laterally outwardly from bore 62 and positioned to receive lower portions 58c of respective locator pins 58. Each pin has its lower portion 58c extending through one of the apertures 64, and its lower end carries an abutment flange 66 wide enough to abut the lower surface of plate 60 about aperture 64 and thus limit upward movement of pin 58 with respect to plate 60. A respective generally annular bearing member 68 surrounds each pin 58 between plates 52 and 60. Bearing member 68 has an annular flange 68a extending ouwardly at its lower end. Flange 68a is wide enough to abut plate 60 about aperture 64 even with substantial lateral movement of pin 58 therein as described below. A respective helical compression spring 70 surrounds each bearing member 68. The upper end of spring 70 bears on the underside of plate 52. The lower end of spring 70 bears on the upper side of its respective flange 68a, which in turn rests on plate 60. Thus springs 70 urge plates 52 and 60 away from each other thereby resiliently supporting female body 20 and its mounting structure 52, 54 on plate 60 for substantial but limited relative vertical movement.
The above arrangement also provides for substantial but limited relative lateral movement between second female body 20 and plate 60 for purposes to be described more fully below. The upper surface of plate 60 serves as a support surface for supporting body 20 via its mounting structure 52, 54 and the interposed springs 70 and bearing members 68. The apertures 64 in plate 60 are substantially wider that the lower portions 58c of locator pins 58 received therein. It is primarily this size difference which allows for the aforementioned relative lateral movement between body 20 and plate 60. However, bearing members 68 provide guidance and control of such movement. More specifically, each bearing member 68 fits closely enough about its respective pin 58 to move laterally therewith. The underside of bearing member 68, including the underside of flange 68a, provides a planar bearing surface for sliding engagement with the upper support surface of plate 60. As previously mentioned, such bearing surface is wide enough to about plate 60 about aperture 64 regardless of the position of pin 58 therein. The bearing surfaces formed by the undersides of bearing members 68, and at least those portions of the upper surface of plate 60 which engage those bearing surfaces, are preferably smoothly finished and lubricated to facilitate relative sliding movement therebetween.
Thus, the assembly comprised of pins 58, bearing members 68, springs 70 and apertures 64 allows for both vertical and lateral movement between body 20 and plate 60, and will be referred to herein as the "compensator means" for body 20. The provision for lateral movement also allows for limited relative rotational or circumferential movement. Depending upon the clearances between the various parts of the compensator means, it may be designed to permit greater or lesser amounts of relative tilting movement in addition to the vertical and lateral movements mentioned above.
Plate 60 is bolted to a larger plate 72 having a central bore 74 substantially wider than the locus of the outer extremities of flanges 66. Plate 72 is in turn bolted to beams 76 which are rigidly connected to a complex of structural members commonly referred to as a "tree" to be mounted on the wellhead structure along with upper female body 20. These structural members include four guide tubes, two of which are shown in the drawings. Each guide tube has a frustoconical portion 78 connected to a respective one of the beams 76 and an upper cylindrical portion 80 adjoining the small upper end of frustoconical portion 78. The guide members 78, 80 are positioned to guide the apparatus shown in FIG. 1 on posts 16 of the wellhead structure in the same manner as the guide members 34, 36 of the lower female body. Thus, members 78, 80 provide gross positioning of the upper female body 20 with respect to the wellhead structure. The tree or structure connected to upper female body 20 also includes a pair of brackets 82 extending laterally inwardly from respective guide cylinders 80. Each bracket 82 has a vertical post 84 mounted at its inner end.
As previously mentioned, the male body 22, which in the embodiment shown is in the form a "driller's pod," along with related apparatus, is run in with the upper female body 20 and tree. Referring to FIGS. 2, 5 and 8, pod 22 has a frustoconical outer surface 86 which is tapered radially inwardly and downwardly to match the taper of receptacle 44 in upper female body 20. A nose piece 88 is rigidly affixed to the lower end of pod 22, while a horizontal plate 90 is fixed to the upper end of the pod and extends laterally outwardly therefrom. Plate 90 carries a pair of guides in the form of laterally outwardly opening channel members 92 which receive posts 84 for providing gross positioning of pod 22 and the attached apparatus with respect to upper female body 20 and the attached tree as the former is lowered into engagement with the latter as shown in FIG. 2. (See also FIG. 3). Flared skirts 94 are formed at the lower ends of channel members 92 to enable such guide channels to skid over joints and other irregularities in the posts 84. A pair of positioning pins 96 are rigidly affixed to the lower side of plate 90 and extend downwardly therefrom. Pins 96 have downwardly and inwardly tapered ends and are positioned for receipt in respective tubes 56 on upper female body 20.
As best seen in FIG. 5, the driller's pod 22 has a plurality of signal communication means directed generally radially outwardly in its tapered outer face 86. More specifically, these include a first or upper set of vertically aligned, circumferentially spaced, signal communication means in the form of inductive electric coupler elements 98. These are designed to mate in one-to-one relation with respective ones of a set of inductive coupler elements 100 directed radially into receptacle 44 of upper female body 20.
Spaced from coupler elements 98, is a second set of signal communication means directed outwardly through pod 22 in the form of vertically aligned, circumferentially spaced hydraulic fluid ports 102. Upper female body 20 has a second set of signal communication means directed radially into receptacle 44 in the form of hydraulic ports 104. The ports 104 are vertically aligned and are spaced below coupler elements 100 by a distance corresponding to the distance between elements 98 and ports 102 of pod 22. Ports 104 are also circumferentially spaced by amounts corresponding to the spacing of ports 102, so that, when coupler elements 98 are matched in one-to-one relation with coupler elements 100, ports 102 will likewise be matched in one-to-one relation with respective ones of ports 104. Each of the ports 102 is substantially wider than the matching port 104 and carries an annular resilient seal 106 thereby ensuring communication without leakage between each set of matched ports 102 and 104. Finally, spaced below ports 102, pod 22 has a third set of vertically aligned, circumferentially spaced ports 108. Ports 108 are substantially identical to ports 102, and in particular, include annular resilient seals 110. Ports 108 are designed to match in one-to-one relation with respective ones of a set of ports 112 in lower female body 18.
In general, it is important to ensure precise coaxial alignment of male body or pod 22 with each of the female bodies 18 and 20, as well as precise relative vertical and circumferential positioning of these bodies, in order to ensure simultaneous proper alignment of the various sets of signal communication means. The width of hydraulic ports 102 and 108, together with the provision of the seals 106 and 110, will permit proper communication of the hydraulic ports while accommodating some misalignment. However, it is still desirable that the hydraulic ports in the male and female bodies be matched as perfectly as possible. More importantly, proper alignment of the various pairs of inductive electric coupler elements 98 and 100 is even more critical to ensure proper operation of these elements. The apparatus of the invention is designed to provide extremely precise alignment by means of various interengagable guide and positioning means which provide increasingly precise degrees of alignment as the various parts are assembled. Furthermore, the apparatus allows for maintenance of such alignment in the assembled apparatus even in the presence of thermal expansion or contraction of associated parts.
Referring again to FIG. 1, upper female body 20 and the connected tree is shown in position for engagement with the pod 22 and attached structures. It will be noted that prior to such engagement, mounting structure 52, 54 and the attached body 20 are urged upwardly by springs 70 to the full extent permitted by abutment flanges 66. As the male assembly is lowered onto the apparatus of FIG. 1, gross initial axial and circumferentially positioning is provided by receipt of guide posts 84 in channel members 92. As the pod 22 approaches female body 20, nose piece 88 will enter receptacle 44 to further guide pod 22 into a centered or coaxially aligned position with respect to body 20. As increasingly larger diameter portions of the tapered surface of pod 22 enter receptacle 44, this centering becomes more precise. In the meantime, pins 96 will have entered positioning tubes 56 carried by body 20. As the cylindrical portions of pins 96 enter smaller and smaller diameter portions of the bores through tubes 56, they provide increasingly fine adjustments of the axial and circumferential alignment of pod 22 with body 20. Finally, when the outer surface 86 of pod 22 seats in receptacle 44, a very precise degree of coaxial alignment is provided, along with precise relative vertical positioning, by virtue of the mating tapers of surfaces 86 and 44. Meanwhile, circumferential positioning is provided by pins 96 and tubes 56. Any lateral or circumferential movement of body 20 relative to plate 60 is permitted by the aforementioned compensator means 64, 58, 68, 70. To further ensure a very precise degree of coaxial alignment between body 20 and pod 22, their mating surfaces 44 and 86 are very carefully machined to extremely close tolerances, preferably using the same jig.
When surface 86 seats on receptacle 44, these surfaces act as stop means to limit further downward movement of pod 22 with respect to body 20. By continued action of the weight of the running-in assembly, pod 22 and body 20 will then be moved downwardly with respect to plate 60, compressing springs 70 as shown in FIG. 2. With the apparatus in this position, pod 22 is connected to body 20 by connection means shown in FIG. 8.
Referring now to FIG. 8, pod 22 has a central longitudinal bore therethrough. This bore includes an upper relatively large diameter section 112. Just below section 112 is a relatively small diameter section 114 which carries an O-ring seal 116. Below section 114 is a relatively large diameter cylinder section 118, below which is an even larger diameter section 120. An actuator member is reciprocably mounted in bore 112-120. The actuator member includes a relatively small diameter main body portion 122 which is recessed to mount a piston assembly 124 intermediate its ends. Piston 124 is provided with the usual seals and mounting rings and is disposed in cylinder section 118 of the longitudinal bore of pod 22. In the running-in position shown in FIG. 8, piston 124 is located at the upper end of cylinder section 118. The lower end of main body 122 of the actuator member is connected by a toggle mechanism (not shown, but well known in the art) in section 120 to a pair of latches 126 mounted on pivot pins 127 in nose piece 88 for lateral extension and retraction. When piston 124 is in its upper postion as shown in FIG. 8, latches 126 are in their retracted positions. When piston 124 and the attached actuator member are lowered, latches 126 are extended as shown in FIGS. 5 and 9. Suitable hydraulic conduits (not shown) are provided in communication with cylinder section 118 for reciprocating piston 124 and the attached actuator member.
The part of main body portion 122 of the actuator member above piston 124 extends through small diameter section 114 of the longitudinal pod bore and engages seal 116 to seal cylinder section 118 from the open upper bore section 112. With piston 124 and main body portion 122 of the actuator in the upper position as shown in FIG. 8, the latter also extends through upper section 112 of the longitudinal pod bore. The actuator member further comprises a relatively large diameter portion 128 adjoined to portion 122 by a transitional tapered cam portion 130. The upper end of bore section 112 is counterbored at 112a and further counterbored at 112b. An annular plate 132 rests in counterbore 112b in spaced relation to counterbore 112a and projects inwardly of the inner diameter of bore section 112 below the counterbores. A cylindrical sleeve 134 is welded to the inner extremity of plate 132 and extends downwardly therefrom within bore section 112 but spaced inwardly from the inner diameter of the latter. Plate 132 is retained on the pod 22 by screws 136.
Pod 22 also has a pair of generally radial bores 138 extending through its upper end and intersecting upper section 112 of its central longitudinal bore. A pair of ejector rods 140 are slidably mounted in respective bores 138. Each rod 140 has a slot 142 therein receiving a pin 144 extending through apertures in plate 90 and pod 22 and threaded into pod 22 below the respective bores 138. The pins 144, in cooperation with slots 142, limit the reciprocating movement of rods 140. In their inner positions as shown in FIG. 8, ejector rods 140 extend through apertures 146 in cylinder 134 and into longitudinal bore section 112 to approximately the outer surface of the small diameter portion 122 of the actuator member.
A pair of cylindrical raceway members 148 are mounted on the upper surface of body 20 and positioned such that their bores will be substantially aligned with bores 138 when pod 22 is properly seated in receptacle 44. Connector pins 150 are slidably mounted in raceway members 148 so that they may project into bores 138. When the male assembly has been engaged with the upper female body and related apparatus as shown in FIG. 2, pins 150 are pushed into bores 138 therby forcing ejector rods 140 into their inner position as shown in FIG. 8. The upper female body 20 is thus connected to pod 22, and the entire apparatus shown in FIG. 2 is ready for running-in.
The apparatus of FIG. 2 is suspended by any suitable means on a wireline or running-in string and lowered toward the wellhead structure, and more specifically, toward the lower female body 18 which has been previously mounted thereon. During this operation, tubular guide members or sleeves 78, 80 provide gross guidance and positioning of the apparatus with respect to the wellhead structure in substantially the same manner as guide sleeves 34, 36 for the lower female body 18. More specifically, wirelines or the like may be extended from the upper ends of guide posts 16 and through tubular guide members 78, 80. As the apparatus is lowered, the tapered portions 78 of the guide sleeves will engage the upper ends of posts 16 and direct them into the cylindrical portions 80 of the guide sleeves. This provides gross axial and circumferential positioning of the interconnected bodies 20 and 22 with the wellhead structure and the lower female body 18.
As nose piece 88 enters increasingly smaller diameter portions of the central bore of body 18, more precise centering or axial positioning is achieved. Such positioning, as well as proper circumferential positioning, is aided by entry of pins 96 into apertures 152 in flange 42 of lower female body 18. The compensator means 64, 58, 68, 70 allows both lateral and circumferential movement of bodies 20 and 22 jointly with respect to guide sleeves 78, 80 to permit these increasingly precise degrees of alignment. The receptacle 38 of lower female body 18 is radially inwardly and downwardly tapered at an angle to correspond to that of outer surface 86 of pod 22. Thus, as pod 22 passes downwardly into receptacle 38, further centering or coaxial alignment occurs. The ultimate or finest degree of coaxial alignment is achieved when tapered surfaces 46 of upper female body 20 seat on tapered surface 40 of lower female body 18. These surfaces not only provide for precise coaxial alignment of lower female body 18 with upper female body 20 and the attached male body 22, but also serve as stop surfaces for providing the proper relative vertical position of the two female bodies.
When surfaces 46 seat on surface 40, preventing further downward movement of upper female body 20, the compensator means, through expansion of springs 70, permit plate 60 and the connected guide sleeves and tree to continue moving downwardly and seat on the wellhead structure. Ideally, compensator means 64, 58, 68, 70 are then in an intermediate vertical position as shown in FIG. 5 whereby the compensator means may further serve to accomodate vertical movement due to thermal expansion and contraction of parts connected to the connector bodies 18, 20 and 22 without misaligning those bodies.
The fact that generally upwardly directed tapered surface 40 of lower female body 18 is inclined radially outwardly and downwardly, as opposed to radially inwardly and downwardly, tends to inhibit the accumulation of debris on that surface and minimize the possibility of interference with proper seating of surfaces 46 thereon. Cut away areas 48 further ensure against such interference by allowing spaces through which any debris, mud, or the like which has settled on surface 40 may be extruded as surfaces 46 press downwardly thereagainst. In other words, surfaces 40 and 46 are effectively self-cleaning.
When body 20 is properly seated on body 18 as shown in FIG. 3, actuator 122, 128, 130 is forced downwardly by fluid pressure applied to the upper end of piston 124. This simultaneously extends latches 126, which lock beneath the underside of body 18, and forces tapered portion 130 and larger diameter portion 128 of the actuator member successively into alignment with rods 140 in bore section 112 of pod 22. As shown in FIG. 9, this will cam ejector rods 140 radially outwardly. When large diameter portion 128 of the actuator member has been brought into abutment with rods 140, they will have been forced outwardly to substantially their full extent thereby forcing connector pins 150 radially outwardly from bores 138. This releases the direct connection between pod 22 and upper female body 20 so that the pod is then positioned solely by the interengagement of its surface 86 with receptacle 44. Of course, engagement of latches 126 with the underside of body 18 will retain pod 22 with respect to both female bodies 18 and 20. When bodies 18, 20 and 22 are fully assembled as shown in FIGS. 5 and 9, pod 22 is centered or coaxially aligned with upper female body 20 by tapered surfaces 44 and 86, which surfaces likewise limit downward movement of pod 22 with respect to upper female body 20. Then, pod 22 and upper female body 20 are jointly centered with respect to lower female body 18 by surfaces 40 and 46, which likewise limit downward movement of body 20 and the pod 22 seated therein. It is important to note that such fine positioning of pod 22 with respect to lower female body 18 is thus accomplished indirectly only, i.e. via body 20, bodies 18 and 22 being sized so that there is a slight clearance between surfaces 86 and 38. As previously mentioned, latches 126 do retain the three bodies in properly assembled position, body 18 effectively being sandwiched between surfaces 46 and the upper surfaces of latches 126. However, said surfaces of latches 126, being co-planar and upwardly directed, do not affect the relative axial alignment of the bodies or downward movement of pod 22. The elimination of direct engagement between surfaces 86 and 38 ensures that body 18 will not interfere with proper seating of pod 22 in body 20, and thus with the maintenance of proper sized gaps between coupler elements 98 and 100, described more fully below. To put it another way, such arrangement provides virtually the same degree of precision in positioning of bodies 22 and 20 as would be achieved if the two female bodies were formed as a single, integral piece, yet with all the advantages of dual, stacked female bodies.
Referring again to FIG. 5, it can be seen that, with the three connector bodies 18, 20, and 22 thus properly seated with respect to one another, each inductive coupler element 98 is precisely aligned with its respective mate 100. Likewise, each hydraulic port 102 or 108 is aligned with its respective mate 104 or 112. As indicated above, receptacle 38 is tapered so as to lie parallel to surface 86 of pod 22, but is sized to be spaced slightly outwardly therefrom when surfaces 86 and 44 and surfaces 46 and 40 are properly seated. This is to prevent surface 38 from interfering with proper seating of the other surfaces. However, the spacing between receptacle 38 and pod 22, which has been exaggerated in FIG. 5 for purposes of illustration only, is very slight, and is accommodated by seals 110 to provide leakproof communication between ports 108 and 112.
When the pod 22 and the upper female body 20 have been properly seated with respect to lower female body 18, each of the inductive electric coupler elements 98 in pod 22 is matched or aligned with its respective mate 100 in female body 20. Likewise, each of the hydraulic ports 102 is aligned or matched with its respective mate 104 in body 20, while each hydraulic port 108 is algined or matched with its respective mate 112 in lower female body 18. Each of the hydraulic ports 102 communicates with fluid passageways through pod 22, e.g. as illustrated at 154 and 156 in FIG. 5. These passageways ultimately lead to hydraulic lines extending away from pod 22 to a suitable source of hydraulic fluid. As previously mentioned, the pod 22 which is illustrated in the drawings is a "driller's pod." In such a pod, these hydraulic lines, as well as electric lines to be described below, lead away from the pod in a bundle or umbilical line which extends upwardly to the drilling ship. In a production pod, to be described more fully below, the hydraulic and electrical lines ordinarily extend to an underwater source of electricity and hydraulic fluid. In either case, the ports 104 in body 20 lead into fluid passageways through that body and ultimately to hydraulic lines which extend to the various valves and other devices to be operated by the hydraulic fluid.
Ports 112 in the lower female body 18 likewise lead into fluid passageways through that body which in turn communicate with hydraulic lines to other operable wellhead devices. Although the mating ports 108 in the male body or pod 22 may communicate with a source of hydraulic fluid, in a driller's pod as shown, ports 108 ordinarily lead only to blind holes provided to carry seals 110 for sealing about ports 112. In a production pod, however, those ports which will mate with ports 112 would lead to hydraulic fluid supply lines.
Referring now to FIGS. 5, 8, 10, and 11, it is necessary that the matching pairs of inductive coupler elements 98 and 100 be disposed in extremely close proximity, but without protruding beyond respective surfaces 86 and 44 so as not to be susceptible to damage during running-in and/or to interfere with proper seating of those surfaces. Several expedients are employed to achieve this purpose. While extending generally radially, each coupler element 98 is mounted in a bore 158 of body 22 whose centerline is perpendicular to surface 86, rather than to true vertical. Likewise, coupler elements 100 are mounted in bores 160 of body 20 which are perpendicular to surface 44. Each coupler element 100 has a head 100a for opposition to the head 98a of the matching coupler element 98 in pod 22. Coupler elements 100 and 98 also have respective annular flanges 100b and 98b extending radially outwardly intermediate their ends. Bore 160 has a relatively large diameter portion 160b opening generally radially outwardly through body 20, and a relatively small diameter portion 160a opening generally radially inwardly into receptacle 44. A shoulder 160 c is thus defined between large and small diameter portions 160a and 160b for cooperating with flange 100b in limiting inward movement of coupler element 100 as it is inserted through large diameter bore portion 160b. To more precisely position head 100a with respect to the surface defining receptacle 44, an annulus of laminated shim stock 164 is interposed between shoulder 160c and flange 100b. The shim stock 164 is comprised of a plurality of extremely thin layers of material which may be peeled off as needed to provide extremely precise positioning of head 100a with respect to surface 44.
After the coupler element has been thus properly positioned, a retainer nut 166 is threaded into large bore portion 160b with its end in abutment with flange 100b to hold coupler element 100 in place. Nut 166 is sealed with respect to bore 160b by an O-ring 168. Coupler element 100 is sealed with respect to nut 166 by an O-ring 170, and with respect to small diameter bore portion 160a by O-rings 172. Wires 174 from coupler element 100 extend into an annular recess 161 in the side of body 20 communicating with bore portions 160b. From recess 161, wires 174 extend through passageways (not shown) to a conduit which in turn leads to a device to be operated by signals communicated between coupler elements 98 and 100. Recess 161 is closed by a sleeve 176 surrounding the upper end of body 20. Sleeve 176 has a radially inwardly extending flange 176a which rests on top of body 20 and is secured thereto by screws 178. Sleeve 176 is also sealed with respect to body 20 above and below recess 161 by O-rings 180 and 182.
Bore 98 has a relatively large diameter portion 158b opening radially outwardly through surface 86 of pod 22 and a smaller diameter portion 158a disposed inwardly thereof, a shoulder 158c being defined between bore portions 158a and 158b. The coupler element 98 is inserted through large bore portion 158b, shoulder 158c cooperating with flange 98b to limit inward movement of the coupler element. An annulus of laminated shim stock 184 is placed between shoulder 158c and flange 98b to precisely position head 98a with respect to surface 86. A nut 186 is then threaded into large diameter bore portion 158b in abutment with flange 98b to retain coupler element 98 in place. Nut 186 is sealed with respect to bore portion 158b by an O-ring 188. Coupler element 98 is sealed with respect to nut 186 by O-rings 190 and with respect to small diameter bore portion 158a by an O-ring 192. Bore portion 158a communicates with an even smaller diameter passageway 194, which in turn communicates with portion 112 of the central longitudinal bore of pod 22 in the protected area defined between the outer surface of bore portion 112 and sleeve 134. Wires 198 from coupler element 98 extend through passageway 194 and the annular space about sleeve 134 into a conduit 196 which in turn extends to the electrical power source.
Proper signal communication between coupler elements 98 and 100 can be achieved if their heads 98a and 100a are placed in close proximity across the central portions thereof. If these heads were flat across the entire width of the coupler elements, one of two undesirable conditions would occur due to the convexity of surface 86 as shown in FIG. 11. Specifically, either the outer edge portions of coupler element 98 would protrude beyond the locus of the arc defined by surface 86, or coupler element 98 would have to be recessed into pod 22 by a distance which would create too large a gap between heads 98a and 100a. On the other hand, formation of head 98a to match the transverse curvature of pod 22 would be extremely difficult and expensive. However, only the central portions of heads 98a and 100a, i.e. the portions generally aligned with the cores 99 and 101 of the respective coupler elements, need be in close proximity. Therefore, the edges of head 98a are chamfered as indicated at 98c beginning at a point located slightly radially outwardly of the O.D. of core 99. This permits the flat central end surface 98d of head 98a to be placed extremely close to the locus of the arc of surface 86, and thus to head 100a, without any portion of head 98a extending beyond that locus. Head 100a is similarly chamfered about its edges as indicated at 100c beginning at a point located slightly radially outwardly of the O.D. core 101. The space between heads 98a and 100a has been slightly exaggerated in FIGS. 10 and 11 for purposes of illustration. However, by means of the expedients described above, the central portions of these heads can in fact be positioned in extremely close proximity to one another without protruding beyond the arcs defined respectively by surfaces 86 and receptacle 44.
Referring once again to FIGS. 5, 9, and 6, once any desired operations on or about the wellhead have been performed by means of the electric and hydraulic connections made up by pod 22 and female bodies 18 and 20, it may be desired to remove pod 22. This is done by applying fluid pressure to the underside of piston 124 to return the actuator member 122, 128, 130 to its upper position thereby retracting latches 126. However, such movement will not alter the positions of connecting pins 150, so that pod 22 will then be disconnected from both female bodies 18 and 20 and can be raised upwardly from the wellhead structure. FIG. 6 shows the two female bodies 18 and 20 and connected apparatus after pod 22 has been removed. It will be noted that, with the weight of pod 22 and the associated assembly removed from female body 20, it will be urged upwardly by springs 70 until abutment flanges 66 touch the underside of plate 60.
Subsequently, either the same driller's pod 22, or another pod known as a "production pod," may be connected to female bodies 18 and 20. The production pod would, for purposes of the present invention, be substantially identical in external configuration to pod 22 and would have connected thereto guidance apparatus and a nose piece similar to those of the driller's pod 22. Thus, for present purposes, the following description of re-engaging of the driller's pod 22 with the female bodies 18 and 20 will be descriptive of the manner in which a production pod would be engaged with those bodies.
Specifically, the pod 22 along with all the connected structures, including the guide structure 90, 92, is lowered toward the upper female body 20. Channel members 92 would engage posts 84 on the tree carried by upper female body 20 to provide gross axial and circumferential positioning of pod 22 with respect to female body 20. As the nose piece 88 enters receptacle 44 followed by increasingly larger diameter portions of pod 22, finer and finer degrees of coaxial alignment of pod 22 and female body 20 are obtained. Meanwhile, pins 96 enter tubes 56 to provide an intermediate degree of axial alignment along with a relatively fine degree of circumferential alignment. When pod 22 seats in receptacle 44, it can begin urging body 20 downwardly toward body 18 until surfaces 46 and 40 engage one another thereby providing a fine degree of coaxial alignment between lower female body 18 and upper female body 20 and the then aligned male body 22. Meanwhile, pins 96 will have entered apertures 152 in flange 42 of female body 18 to provide the necessary circumferential alignment of body 18 with bodies 20 and 22. In short, the apparatus would resume the relative positions shown in FIG. 5 and latches 126 could be re-extended to hold the connector bodies in that position. As before, the compensator means connecting female body 20 with plate 60 would allow for any necessary lateral, circumferential, or longitudinal movement of body 20 relative to bodies 18 and 22 in order to achieve the desired fine degree of alignment.
As previously mentioned, a production pod could be guided into place, with increasingly fine degrees of alignment, on bodies 18 and 20 in substantially the same manner, the primary difference between a production pod and a driller's pod being the location of the source from which it receives its electrical and hydraulic fluid power.
The above description represents one preferred embodiment of the invention, and it should be understood that numerous modifications could be made. Accordingly, it is intended that the scope of the invention be limited only by the claims which follow.
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The invention pertains to apparatus for connecting to a wellhead structure. Lower and upper female bodies define first and second receptacles disposed generally in coaxially aligned, end-to-end, communicative relation. A male body is received in both receptacles. The male body and upper female body have respective sets of inductive electric couplers matched in one-to-one relation. Several features facilitate effective use of such couplers: the couplers themselves have the edges of their heads chamfered from a point located just outwardly of the O.D's of their cores; an improved mounting arrangement aligns the two female bodies in stacked relation without the lower female body interfering with proper seating of the male body in the upper female body; an improved compensator system enhances play of one female body for precise centering with the other.
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BACKGROUND AND SUMMARY OF INVENTION
Beer kegs and the like have valves that can be operated by attaching tavern fittings to the kegs. The tavern fittings are detachable from the kegs and from the keg valves when the kegs are in storage or in transit.
Tavern fittings which connect the kegs with the beer faucets at a bar are auxiliary equipment that may be considered a permanent part of the bar. There are a wide variety of tavern fittings and they must be compatible with the valves in the kegs that the tavern obtains from the brewery from which the beer is purchased.
This invention is an improvement in the tavern fittings shown in patent application, Ser. No. 868,492, filed Jan. 11, 1978 (now U.S. Pat. No. 4,180,189). The check valve of the fitting referred to is in a chamber with the downstream side closed by a threaded hose connection which is permanently secured with a sleeve through which beer flows from the tavern fitting to the beer hoses that lead to faucets at the tavern counter. The hose connection requires machine work for its manufacture at its lower end to provide cross channels that add to the cost of the patented fitting and that cannot be cleaned as easily as the construction of the present invention.
This invention provides a simplified construction in which the sleeve that contains the check valve is of one-piece construction with the threads for the tavern hose on the outside of the sleeve through which the beer flows. The movement of the check valve away from its seat is controlled by a spring that is tapered and coiled with its largest coil in a groove in a wall of the sleeve and with the smallest convolution of the spring in contact with the check valve.
Alternatively a bushing that fits into the sleeve with a slide fit and with an integral flange that contacts with the end face of the sleeve is cast with the necessary cross passages in the end face which limits movement of the check valve.
A probe in the tavern fitting is pushed down by cams operated by a manually-operated handle in said patent, and returns to normal position by pressure of a spring which may not have sufficient force if the beer line has not been cleaned for a long time. This invention provides positive movement of the probe in both directions and the operator can feel the resistance to movement.
Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.
BRIEF DESCRIPTION OF DRAWING
In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views;
FIG. 1a is a sectional view through the improved tavern fitting of this invention and shows the way in which the tavern fitting is connected with a keg fitting through which the beer is withdrawn from a beer keg;
FIG. 1b shows a modified construction at the top of the structure shown in FIG. 1a;
FIG. 2 is an isometric view of the top of the structure shown in FIG. 1a and illustrating the way in which a split washer is inserted into a circumferential groove in the upper part of the probe shown in FIG. 1a;
FIG. 3 is a bottom elevation of the bushing which fits into the top of the prove in FIG. 1a;
FIG. 4 is a side elevation of the bushing shown in FIG. 3;
FIG. 5 is a diagram showing the way in which the cam followers on the top handle of FIG. 1a operate to depress the probe when the upper handle is rotated; and
FIG. 6 is a plane view of the spring of FIG. 1b before being inserted into the groove.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1a shows a portion of a beer keg 10 with an opening 12 into which a neck 14 is inserted and secured to the keg 10 by welding 16. A spherical valve 18 closes against a seat 20 which is held in the neck 14 by a frame 22 held in the neck 14 by split rings 24 that hold the frame 22 against sealing rings 26. The construction thus far described is conventional.
A tavern fitting designated generally by the reference character 28 connects with the keg fitting neck 14 by a bayonet type connection 29 grooves in the frame 22 and holds a sealing ring 31 in contact with the frame 22. The bayonet lock 28 thus secures the tavern fitting to the neck 14 rigidly in accordance with conventional practice, and a probe 30 is located in the housing of the tavern fitting 28 and has a passage 32 through which beer flows from the keg when the valve 18 is opened by the probe moving down and displacing the valve 18 from its seat 20.
There is a check valve 34 in the passage 32 and the passage has a reduced diameter at its lower end to provide a seat for the check valve 34, as shown in FIG. 1a. When gas is flowing from the keg toward the upper end of the probe 30, the check valve 34 will move upward above its seat; and the check valve 34 may move to the position shown in dotted lines in FIG. 1a but it cannot block the upward flow because it is restrained by protuberances 36 at the lower end of a bushing 38 which fits into the upper end of the probe 30. Details of this bushing 38 will be described in connection with FIGS. 3 and 4.
A tubular sleeve-discharge fitting or hose connector 40 has a face which contacts with the upper end of the bushing 38 to clamp a flange 42 at the end of the bushing 38 against a top face of the probe 30. Threads on the hose fitting 40 screw over complimentary threads 44 to secure the hose fitting 40 to the upper end of the probe 30.
A handle 46 has a center hub 48 which has a cylindrical chamber 50 that opens downwardly and fits over the upper end of fixed housing of the tavern fitting 28. A coil spring 52 surrounds the probe 30 within the chamber 50. This spring 52 seats against a surface of the fixed structure of the tavern fitting 28 at the lower end of the spring and is held under pressure by a washer 54 which is a slit ring that snaps into a groove 56 in the circumference of the probe 30.
Downward movement of the handle 46 and its hub 48 is obtained by rotating the handle, causing a cam follower 60 to follow a cam track 62 (FIG. 5) formed in the outside surface of the stationary wall of the tavern fitting 28. Rotation of the handle 46 and hub 48 moves the cam follower 60 along the cam track 62 and causes the handle to move downwardly until it reaches the position shown in dotted lines at the end of the cam track shown in FIG. 5.
Any time that the downward pressure on the handle 46 is release (FIG. 1a) the cam follower 60 will be held against the top of the cam track 62 (FIG. 5). There is a rise 64 at the end of the cam track 62 so that any time that the cam follower 60 moves beyond the downwardly sloping track 62 and enters the rise at the end of the cam track, the upward spring pressure will hold the cam follower 60 in the dotted line position shown in FIG. 5. This maintains the probe in its lowermost position and keeps the valve 18 (FIG. 1a) open so that beer can flow from the keg.
If the handle 46 and hub 48 are to be removed from the fixed part of the tavern fitting 28, the handle 46 and hub 48 are held down against the pressure of the spring 52 so that the cam follower 60 (FIG. 5) can be moved along the straight portion 66 until the handle has rotated far enough to bring the cam follower 60 to vertically extending flat area 68 on the side of the fitting 28 so that the cam follower 60 can be removed from the cam track.
In tavern fittings of the prior art, where the probe was depressed by cam structure such as shown in FIG. 5, there was no positive way for compelling the probe to rise when the follower 60 was not lifted by the spring under the handle that operated the cam mechanism. If the inside of the tavern fitting were gummy from inadequate cleaning, the probe would stay in a depressed condition and hold the key valve open. If a tavern fitting were disconnected from a keg with the probe still in a depressed position which held the keg valve open, then lifting of the tavern fitting on which the handle had been turned into position to close the keg valve, would cause beer to spray out of the keg as the tavern fitting was disconnected from the keg without knowing that the probe was holding the keg valve open. This caused beer to spray out between the tavern fitting and the open keg valve with waste of beer and extensive clean-ups.
FIG. 2 shows an improvement which prevents accidents caused by disconnecting the tavern fitting from the keg when the tavern fitting probe is still holding the keg valve open because the probe spring 52 did not raise the probe when the handle 46 was rotated into position where the probe would be raised under normal operating conditions. A split washer 70 is shown in FIG. 2 in the process of being inserted into a slot 72. FIG. 1a shows the washer 70 after insertion into the slot 72 and the width of the split washer 70 is sufficient to extend over the top of the hub 48 of the handle 46 so that when the cam track raises the handle, the probe 30 is forced to rise with the handle so that when the handle reaches the position where the keg valve should be closed it will always be closed because the probe will be at the same position as it would be if the spring 52 raised the probe. The washer 70 has three faces 74 which contact with the inner face of the groove 72 and other portions of the washer can bend as necessary when inserting and removing the washer from the groove 72. This expedites disassembly of the tavern fitting when necessary for cleaning.
FIGS. 1a, 3 and 4 show the preferred construction for preventing the check valve 34 from unduly obstructing the free flow of beer through the probe 30 on its way to the hoses or pipes leading to the tavern faucets. At the upper end of the probe 30 the bushing 38, preferably fits into the probe with a pressed fit and the flange 42 is preferably a molded fitting of suitable plastic material. The flange 42 is preferably made with circumferential beads 76 on the upper and lower surfaces of the flange 42. When the flange is clamped between the hose fitting 40 and the upper end surface of the probe 30, these beads contact with flat annular surfaces so that the areas of contact are reduced and the unit pressure at the beads is proportionately increased so that the beads serve as seals to prevent leakage of beer at the connection between the hose fitting and the threads 44 of the probe. The sidewalls of the bushing 38 have open areas 78 which extend for most of the height of the bushing to provide more open area for the flow of beer.
FIG. 1b shows a probe 30' with threads 44' screwed into complimentary threads of a hose fitting retainer 35 and with a packing washer 80 compressed between the upper end of the probe 30' and a confronting face of a beer hose nipple 37.
In order to limit the upward movement of the check valve 34' in the probe 30', there is a spring clip 82 which has a circumferential top loop which fits into a groove 84 in the inside surface of the probe 30'. The spring 82 is flat and is shown in FIG. 6 before being inserted into the groove 84. The spring clip 82 can be removed from the groove 84 and the check valve 34' also removed when cleaning the beer line, just as the bushing 38 can be removed from the probe in FIG. 1a when cleaning the line.
In the construction shown in FIG. 1b, the groove 84 is preferably located about 1/8 inch from the upper end of the probe 30'. This makes the removal of the spring clip convenient and removal of the check valve 34' also convenient.
The preferred embodiments of the invention have been illustrated and described but changes and modifications can be made and some features can be used in different combinations without departing from the invention as defined in the claims.
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This invention is an improvement in tavern fittings that are used for dispensing beer from kegs, and it is for the purpose of simplifying the construction of the equipment and the dispensing of beer more efficiently. The construction lends itself to easier cleaning of beer dispensing equipment as the result of more convenient disassembly for cleaning and subsequent reassembly. One feature of the invention insures the closing of the keg valve, even though the tavern fitting is so dirty that it sticks in the open position when the tavern fitting of the prior art is moved into position to close the keg fitting valve.
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FIELD OF THE INVENTION
The present invention relates to a method and apparatus for rotatably suspending production tubing in a well bore and more particularly to a rotatable dognut tubing anchoring system including in some cases a downhole clutch for rotatable connection between the tubing and a tubing anchor.
BACKGROUND OF THE INVENTION
There are approximately 50,000 active pumping wells in Western Canada of which approximately 9,000 operate with rotary pumps and the vast majority of the remainder using beam pumps of which approximately 10,000 are high volume lift pumps.
These high volume beam pumps are commonly afflicted with a severe tubing wear problem due to frictional contact between the pump sucker rod and the inner surface of the tubing which ultimately causes tubing perforations, leakage and the need for expensive tubing repairs and/or replacement. In the case of rotary pumps, the problem can be even more severe where the sucker rod rotates within the tubing string at rates of 250 to 600 rpm and where torque from the rotating rod string can actually over-torque the tubing string couplings to cause a complete tubing failure.
Production tubing is normally simply non-rotatably suspended in the well bore from a conventional tubing hanger. However, if the production tubing is suspended rotatably in the Well, the problem of rod-to-tubing wear and over-torquing can be substantially alleviated. By periodically rotating the tubing, rod wear in the string is spread evenly around its inner circumference to prolong tubing life and reduce workover costs. Rotatable suspension of the string will also relieve torque buildup associated with rotary pumps particularly when turning at high rpm for pumping heavy concentrations of viscous sand, water and heavy oil mixtures.
While providing these and other advantages, the present system also enhances the well operator's ability to comply with subsisting legislation requiring that during well completions, servicing or reconditioning, the well must be under control and blowout preventers must be installed and maintained to shut down any flow from the well. The present anchoring system is adapted to remain in place attached to the tubing string while the well head is removed and the service rig blowout preventer is installed so that a plug can be installed into the tubing string after the pump rod has been removed to shut off all flow. This plug can be installed through the well head prior to its removal so that the flow is stopped as the service rig blowout preventer is installed.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to obviate and mitigant from the disadvantages the prior art.
It is a further object of the present invention to provide a tubing anchoring system which allows production tubing to rotate or be rotated within the well bore.
In one broad aspect the present invention relates to an apparatus for rotatably supporting a tubing string in a well bore comprising tubular coupler means connectable to an uphole end of a tubing string, hanger means disposed annularly about said coupler means in fixed axial relationship thereto, said coupler means being rotatable relative to said hanger means, bowl means for supporting said hanger means therein such that a tubing string connected to said coupler means can be suspended in the well bore, and drive means operably connected to said coupler means and extending through said bowl means for actuation to rotate said coupler means and a tubing string connected thereto.
In another broad aspect the present invention relates to a clutch for providing a rotatable connection between the downhole end of a tubing string and a tubing anchor adapted for connection to an internal surface of a well bore, said clutch comprising a first tubular sub having an uphole and a downhole end, said uphole end being adapted for connection to the downhole end of a tubing string, a second tubular sub having an uphole and a downhole end, the uphole end of said second tubular sub being disposed annularly about said downhole end of said first tubular sub, the downhole end of said second tubular sub being adapted for connection to a tubing anchor, and connector means disposed between said first and second tubular subs, said connector means being adapted to initially prevent relative rotation between said first and second tubular subs for transmission of torque through said clutch means to a tubing anchor connected thereto, said connector means actuatable thereafter to permit relative rotation between said first and second tubular subs.
In another broad aspect the present invention relates to a method of rotatably suspending a tubing string in a well bore comprising the steps of connecting the uphole end of a tubing string to coupler means, rotatably suspending said coupler means from a tubing hanger, connecting said coupler means to drive means by which torque can be transmitted through said drive means to said coupler means for selectively rotating said coupler means by a predetermined amount.
In another broad aspect the present invention relates to a method of rotatably connecting the downhole end of a tubing string to a tubing anchor in a well bore, comprising the steps of connecting the downhole end of said tubing string to a first tubular sub, connecting said tubing anchor to a second tubular sub, providing an initial connection between said first and second tubular subs preventing both relative rotation and axial separation therebetween; fixing said tubing anchor in place in said well bore by means of torque transmitted through tubing string and said first and second tubular subs to said tubing anchor, and rupturing said initial connection between said first and second tubular subs by means of tension applied to said first tubular sub, whereupon said first and second tubular subs may be axially separated by a predetermined amount so that one can rotate relative to the other and so that said tubing string is then rotatable relative to said tubing anchor.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described in greater detail and will be better understood when read in conjunction with the following drawings, in which:
FIG. 1 is a schematical partially cross-sectional view of production tubing suspended in a deviated well bore from a modified tubing hanger as described herein;
FIG. 1a is a cross-sectional view of the tubing along lines 1a--1a in FIG. 1.
FIG. 2 is a side elevational, cross-sectional view of a coupling attached to the top of a production tubing string;
FIG. 3 is a side elevational, cross-sectional view of the coupling of FIG. 2 with a modified tubing hanger dognut assembly thereon;
FIG. 4 is a side elevational, cross-sectional view of the tubing hanger of FIG. 3 in a tubing hanger bowl, including a drive mechanism for engaging and rotating the coupling and the tubing attached thereto;
FIG. 5 is a side elevational view of a wrench adapted for actuating the drive mechanism on the tubing hanger of FIG. 4;
FIG. 6 is a schematical, partially cross-sectional view of production tubing suspended between the hanger of FIG. 2 and a tubing anchor;
FIG. 7 is a side elevational, cross-sectional view of a clutch member providing a rotatable connection between the downhole end of the tubing string and a tubing anchor; and
FIG. 8 is a side elevational view of a splined seal retainer forming part of the clutch of FIG. 7.
DETAILED DESCRIPTION
In FIG. 1, production tubing 9 is shown suspended from the present tubing hanger 1 down a well bore 8 lined with a cemented-in casing 7. A pump sucker rod 4 passes downwardly through the well head 2 (shown only in part), through hanger 1 and down tubing 9 to a downhole pump (not shown). Although well bore 8 will often be vertical, FIG. 1 depicts a deviated well bore to better illustrate the aggravated nature of the rod-to-tubing wear problem in this environment, particularly as further shown in the side bar cross-sectional view of the contact between the rod and tubing at the point where the well deviates (FIG. 1a).
With reference now to FIG. 2, the top 10 of tubing string 9 is shown threadedly connected to a tubular coupling 20 which forms the inner core of the uphole portion 1 of the present anchoring system as will be described below. Coupling 20 is internally threaded at its uphole end 19 for connection to a flow stopping plug (not shown), and is formed with a circumferential radially extending flange 21, a small shoulder 22, a plurality of radially spaced-apart key slots 24 and an external box thread 28.
With reference to FIG. 3, coupling 20 is shown with tubing hanger assembly 40 installed thereon, including a bearing assembly that allows the coupling to rotate relative to the hanger and a spiral bevel gear 60.
Tubing hanger 40 consists of upper and lower hangers or dognuts 42 and 52 respectively, threadedly connected together at 41. Flange 21 is flanked on each of its upper and lower surfaces by thrust bearings 30 which themselves are sandwiched between thrust rings 31. A needle roller bearing 33 and a cooperating race ring 34 are installed around coupling 20 as shown with the upper end of the roller bearing abutting against shoulder 22. Sealing between assembly 40 and coupling 20 is provided by means of polypak seals 26. Additional sealing between upper and lower dognuts 42 and 52 is provided by O-ring 5.
As will be appreciated, the weight of tubing string 9 is transferred to thrust bearings 30 which, together with needle bearing 33, allows coupling 20 to rotate relative to dognuts 42 and 52.
Spiral bevel gear 60 is non-rotatably connected to coupling 20 by means of keys 59 that fit into key slots 24 in the coupling surface and into correspondingly opposed key slots 61 formed in the inner peripheral surface of the gear. A bushing 62 separates the upper surface of gear 60 from the lower surface of lower dognut 52 and the gear is retained in place by a gear retaining cap 63 which connects to box threads 28 on the outer surface of coupling 20. A set screw 65 prevents retaining cap 63 from accidentally backing off.
As will be described below, gear 60 forms part of the drive mechanism for rotating coupling 20 and tubing string 9 connected thereto.
With reference now to FIG. 4, coupling 20 and hanger assembly 40 are shown suspended in a hanger bowl 80 with bevel gear 60 meshed with a mating pinion 100 to form a 90° contact.
As will be seen from FIG. 4, bowl 80 is substantially tubular to support hanger assembly 40 therein by means of contact between an external annular shoulder 29 on lower dognut 52 and an internal cooperating annular shoulder 79 in bore 78 formed through bowl 80.
As aforesaid, bevel gear 60 meshes with pinion 100 which in turn is connected to a shaft 90 which orthogonally exits the hanger bowl through a threaded aperture 82 formed in the bowl's side. Pinion 100 non-rotatably connects to shaft 90 by means of keys 91 and is retained in position by a snap ring 99.
Shaft 90 is centered in aperture 82 by means of a sleeve 93 threaded at its inner end 94 to connect to the pipe threads 83 in aperture 82. Sleeve 93 encloses a bearing ring 97 and needle roller bearings 95 to rotatably support shaft 90 therethrough. Sealing between the shaft and sleeve 93 is provided by polypak seals 96.
Sleeve 93 is externally box threaded for connection to a correspondingly internally threaded housing 120 which, when installed, holds roller bearings 95 in place and also maintains a proper mesh between gear 60 and pinion 100. Housing 120 also encloses a spring loaded ratchet pin 110 that makes contact with ratchet teeth 98 on shaft 90. Ratchet pin 110 is biased against the ratchet teeth on shaft 90 by means of, for example, a spring 111 which is enclosed by a spring backup plate 112 held in place by threaded fasteners 113. A small bushing 115 is placed between teeth 98, housing 120 and shaft 90. A collar 126 is threaded onto shaft 90 behind housing 120 to restrict axial movement of the shaft. A bushing 121 separates collar 126 from housing 120 and a pin member (not shown) can be inserted into a hole 129 formed through the collar and shaft to prevent the collar from backing off. As will be seen, the outer end 104 of shaft 90 is exposed for connection to a wrench or other prime mover for rotation of the shaft. Ratchet teeth 98 are formed to allow only counter-clockwise rotation of shaft 90. Because of the orientation of gear 60 and pinion 100, counter-clockwise rotation of shaft 90 will cause clockwise rotation of coupling 20 and tubing 9 suspended therefrom.
As will be appreciated, the tubing string is now free to rotate in the clockwise direction and can be incrementally rotated at will by counter-clockwise rotation of shaft 90.
Installation of the present anchoring system will now be described for those situations where a downhole tubing anchor is not required so that the tubing string need not be tripped out from the well.
A service rig is moved onto the well and the well is then killed (if necessary). A blowout preventer stack is installed and the sucker rod and bottom hole pump are then removed from the well. At this point, the tubing string in the well is picked up and the existing dognut hanger is removed. The top of the tubing is then plugged temporarily using, for example, a TOOLMASTER POST LOCK™ bridge plug. The tubing and the temporary plug are then run below the surface so that the well is temporarily sealed. The existing hanger bowl is removed and a bowl 80 is installed in its place. The bridge plug and tubing string are then picked up and the plug removed.
At this point, the tubing string is rotated using power tongs with a torque gauge connected thereto. In this way, the maximum torque needed to rotate the string can be determined and also to ensure that the torque applied to the string by the present system does not exceed the string's makeup torque.
After establishing these torque figures, coupling 20 with hanger assembly 40 installed thereon is connected to the top of the tubing string, which is then slowly and carefully lowered into hanger bowl 80 to ensure that gear 60 properly meshes with pinion 100 which has previously been inserted through aperture 82.
Once the present system has been installed as described above, shaft 90 can be actuated by means of a wrench or a torque transmitting motor. A specially adapted wrench 150 developed by the applicant for this purpose is shown with reference to FIG. 5 and includes a shear pin system 152 designed to shear off when the applied torque is slightly less than the makeup torque of the tubing string. Shear pin 152 will also rupture to protect the operator should excessive feedback torque from the tubing string be transmitted through shaft 90. With wrench 150 engaged, the operator will apply left hand or counter-clockwise torque to apply right hand or clockwise torque to coupling 20. Ratchet teeth 98 are splayed to allow 18° of rotation between engagements of ratchet pin 110. The wrench can therefore be removed if desired after every 18° cycle. By rotation of the string in this way, a different inner surface of the tubing is exposed to sucker rod wear. In the case of rotary pump applications, rotation of the string can relieve torque buildups.
A somewhat different approach is required if the downhole end of the tubing string is connected to a tubing anchor. With reference to FIG. 6, a tubing anchor 275 is normally non-rotatably secured to the casing 7 to hold the tubing string 9 in place and, if needed, in tension. Obviously, the otherwise fixed connection between the string and the anchor will defeat the purposes and advantages of the improved hanger described herein by preventing the string from rotating freely. The applicant has therefore developed a downhole clutch 200 to provide a rotatable coupling between the lower end of the string and the tubing anchor.
With reference to FIGS. 7 and 8, clutch 200 includes, starting at its uphole end 201, a tubular top sub 210 internally threaded at 211 for direct threaded connection to the bottom of the tubing. Sub 210 thins into a cylindrical mandrel or stinger 212 which is externally box threaded at its downhole end 213. Top sub 210 additionally includes a set of circumferential, spaced apart teeth or splines 215 adapted to mesh with correspondingly shaped opposed splines 219 formed on a seal retainer 225 which fits annularly onto the outer surface of stinger 212. The shape and orientation of splines 219 on seal retainer 225 are best seen from FIG. 8. Retainer 225 is additionally temporarily attached to top sub 210 by one or more shear screws 227 of a soft metal such as brass or metal steel.
The seal retainer is internally box threaded at 229 for connection to a correspondingly externally threaded tubular bottom sub 250. Bottom sub 250 is also externally threaded at its downhole end 202 for direct connection to the tubing anchor (not shown).
Between the outer surface of stinger 212 and the inner surface of the bottom sub immediately downstream of seal retainer 225 is a seal ring 240 to provide sealing against rotational and static leaking by means of O-rings 207 and polypak seals 208. One or more set screws 235 hold seal ring 240 in place and prevent the accidental backing off of the bottom sub from seal retainer 225.
Finally, a cylindrical bearing cap 260 is threaded onto the downhole end 213 of mandrel 212 with upper surface 262 of the cap providing a shoulder on which a bearing assembly 270 rests.
As seen in the upper half of FIG. 7, with splines 215 and 219 engaged and shear screws 227 intact, rotation of top sub 210 relative to bottom sub 250 is not possible. Thus, with the clutch and anchor secured to the bottom of the tubing, the anchor is run into the hole to the desired depth and a right hand rotation of the string will set the anchor as is conventional in the art. With the anchor thusly set tension is applied to the string and into the clutch to cause shearing of screws 227 and the separation of splines 215 and 219. As best seen from the lower half of FIG. 7, this will bring the bearing assembly 270 resting on the bearing cap into contact with the lower end of seal ring 240. This prevents separation of the top and bottom subs and facilitates relative rotation therebetween. It follows that top sub 210 and the tubing connected thereto are now free to rotate relative to the bottom sub and the tubing anchor.
Installing the present system where a tubing anchor is required is similar to the method described above with the obvious exception that the tubing string must be pulled for attachment of clutch 200 and the tubing anchor. The tubing is then tripped back into the hole to set the anchor and disengage the clutch. Once the clutch has been sheared, the tubing string can be freely rotated between hanger assembly 40 and clutch 200.
The above-described embodiments of the present invention are meant to be illustrative of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications, which would be readily apparent to one skilled in the art, are intended to be within the scope of the present invention. The only limitations to the scope of the present invention are set out in the following appended claims.
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There is described a method and an improved apparatus for rotatably suspending a tubing string in a well bore, the apparatus comprising a tubular coupler connected to the uphole end of the tubing string, a tubing hanger disposed annularly about the coupler in fixed axial relationship, the coupler being rotatable relative to the hanger, a hanger bowl for supporting the hanger therein so that the tubing string connected to the coupler can be suspended in the well bore and a drive system operably connected to the coupler and extending through the hanger bowl which can be actuated to rotate the coupler and hence the tubing string attached thereto.
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BACKGROUND OF THE INVENTION
This invention relates to the sport of archery, and especially bow hunting. Bow hunters must stalk or wait for game to come within range often for a considerable period of time before an opportunity to shoot arises. Due to the time and noise required to properly nock, draw and fire an arrow, the game may be alerted and attempt to flee. Hunters may try to maintain their bow in a partially cocked position, however, the tension required by modern compound bows results in muscle fatigue and a loss of shooting accuracy.
Available bow cocking mechanisms have varied hinged attachments which partially obscure the archer's view of the target. Such existing devices only partially cock the bow, requiring the hunter to manually draw, aim and maintain an arrow in the fully cocked position until release. The existing devices are cumbersome to set and do not allow a bow hunter to react quickly enough. Existing hinged devices which extend perpendicularly in linear alignment from the bow shaft to the bow string are unstable and may be dangerous to use due to the potential for misfiring.
SUMMARY OF THE INVENTION
The present invention provides a brace for an archery bow to hold the bow string and nocked arrow in a cocked position. The invention permits the archer to maintain the bow in the cocked position for any desired period of time. The invention provides a brace which is stabilized by opposing angular forces created throughout the various elements thereof. The brace of the present invention has front, middle and rear brace legs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the brace of the present invention mounted in a compound bow in the cocked position.
FIG. 2 is a top view of the brace of the present invention mounted in a compound bow in the cocked position with the arrow shown in dashed lines for clarity of the brace.
FIG. 3 is a side view of the brace of the present invention showing an alternate angular adjustment of the first brace leg in dashed lines.
FIG. 4 is a side view of the brace of the present invention mounted in a compound bow in the un-cocked position.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, a brace 10 for an archery bow 12 is provided by the invention. An archery bow 12 commonly has a bow frame 13 with an upper limb 14 and a lower limb 16, and a bow string 18 disposed therebetween. Modern compound bows commonly used for hunting may be equipped with pulleys or other features, however, the present invention is adapted for use with all bow models. The brace 10 generally has a front leg 20, a middle leg 30 and a rear leg 40. The legs 20, 30, 40 of the brace 10 can be constructed of hard durable material such as metal, wood or plastic. Preferably, the legs 20, 30, 40 are constructed of a strong, light weight metal alloy, such as aluminum.
The brace 10 has a front brace leg 20 with a first end 22 and a second end 24. The first end 22 is adapted to be removably attached to the bow frame 12 such that the front brace leg 20 extends perpendicularly from the bow frame 12 towards the bow string 18. The brace 10 can be mounted on the bow 12 by different fastening devices, such as by a pair of bolts 21 inserted through the first end 22 of the front leg brace 20 and through the bow frame 13. The front brace leg 20 of the preferred embodiment has a generally C-shaped first end 22 for removable attachment to the front of the bow frame 13, which has holes therethrough to receive the two bolts 21. As seen in FIG. 2, the front brace leg 20 has a horizontally angled portion 26 to provide an additional stabilizing shape to the brace 10. Attachment of the brace 10 is preferably made at a point just below the middle, or belly, of the bow frame 13.
The middle brace leg 30 also has a first end 32 and a second end 34. The first end 32 of the middle brace leg 30 is pivotally attached adjacent to the second end 24 of the front brace leg 20. This attachment is adapted for longitudinal rotation. Pivotal attachment may be made by a variety of hinging systems. An axial pin 35 may be inserted through the juxtaposed ends of the front 20 and middle 30 legs, as shown.
A first pivot stop means for selectively preventing the front brace leg 20 from pivoting at a predetermined point relative to the middle brace leg 30 is also provided. In one preferred embodiment, the first pivot stop means is positioned proximal to the attachment of said front brace leg 20 and said middle brace leg 30. The first pivot stop means is shown as a flange 37 extending from the second end 24 of the front brace leg 20. The flange 37 thereby prevents the front brace leg 20 from pivoting at a predetermined point relative to said middle brace leg 30.
In preferred embodiments, the flange 37 can be further equipped with a set screw 38 for optimizing the predetermined point at which the front brace leg 20 is prevented from pivoting relative to said middle brace leg 30. As shown in FIG. 3, the set screw 38 can be rotated to extend downward towards the middle brace leg 30 such that a downward angle A of 180 degrees or less is formed by the longitudinal axes of the middle 30 and front 20 brace legs relative to each other. The set screw 38 permits an adjustable range of angles for tuning the brace 10 to a variety of bow types and archer preferences.
A rear brace leg 40 is also provided, which has a first end 42 and a second end 44. The first end 42 is pivotally attached adjacent to the second end 34 of the middle brace leg 30 and is adapted for longitudinal rotation. Again, pivotal attachment may be made by a variety of hinging systems, such as by an axial pin 45 inserted through the juxtaposed ends of the middle 30 and rear 40 legs, as shown.
A second pivot stop means for selectively locking the middle brace leg 30 relative to the rear brace leg 40 at an upward angle B of less than 180 degrees is provided. Preferably, this angle B of less than 180 degrees is in the upward direction, however, the opposite configuration, including that corresponding to the normally downward angle A of the first pivot stop means, is also contemplated by the invention. The angle B between the middle 30 and rear 40 brace legs is preferably between about 120 degrees and 175 degrees, and more preferably about 160 degrees. In the cocked position, the brace legs 30, 40, 50 are selectively prevented from pivoting longitudinally by the first and second pivot stop means.
As shown, the second pivot stop means is located proximal to the attachment of said middle brace leg 30 and said rear brace leg 40. The second pivot stop means shown has a spring loaded pin 47 on the first end of said rear brace leg. The pin 47 is in selective communication with a corresponding pin receptacle 48 on the second end 34 of said middle brace leg 30. As the brace is extended into the fully cocked position, the pin receptacle 39 is exposed to the spring loaded pin 47, which enters the receptacle 39 and locks the middle 30 and rear 40 brace legs in a relative angle B of less than 180 degrees.
The pin 47 has a ring 48 attached to one end thereof to facilitate removing the pin 47 from communication with the receptacle 39. As shown in FIG. 4, The locking mechanism on the second pivot stop means can be released by pulling the ring 48 and pin 47 slightly outward against the spring load to disengage the rear 40 and middle 30 legs for folding the brace 10 in the un-cocked position. The bow 12 and brace 10 may be easily transported and stored as a single unit in the un-cocked position.
The brace 10 of the present invention carries tension in both horizontal and vertical dimensions. Horizontal forces are carried from side to side between the bow 12 and bow string 18 as usual. The formation of the angles A,B defined by the first and second pivot stop means, however, provides the additional stabilizing vertical forces. The present invention provides a vector of force from the bow string 18 downward through the rear leg brace 40 to the second pivot stop. This force is countered by the upward force exerted from the lower portion of the bow frame 16 against the first end 22 of the front brace leg 20 to the first pivot stop. Thus, these vertically opposing angles of force through the front 20, middle 30 and rear 40 legs allow an increased amount tension to be maintained versus other linearally-stabilized bow cocking devices. The present invention utilizes the principle of leverage throughout the front 20, middle 30 and rear 40 legs to transfer and balance the forces required to maintain the bow 12 in the cocked position. This additional force load capacity is also necessary for maintaining the fully cocked position of many modern compound bows.
As mentioned previously, in one preferred embodiment the angle A of the front brace leg relative to the middle brace leg can be adjusted using the set screw 38 on the first pivot stop means, or flange 37. Thus, these vertically opposing angles of force through the front 20, middle 30 and rear 40 legs allow a variable amount of tension.
A means for attaching a bow string catch 50 adjacent to the second end 44 of the rear brace leg 40 is also provided as a hole or notch 41. The bow string catch 50 permits selective release of the bow string 18 by the archer. The bow string catch 50 is a commercially available, manually releasable bow string catch connected proximal to the second end 44 of the rear brace leg 40 by a cord 52. The length of the cord 52 will also affect the amount of tension carried by the brace 10, and can be adjusted for the particulars of any situation. The bow string catch 50 generally holds the bow string 18 and nocked arrow 55 until a mechanical switch is moved to release the catch 50. The invention contemplates that a variety of known bow string catches may be adapted for use with the present invention.
The preceding embodiments are intended to illustrate, but not limit, the invention. While they are typical of those that might be used, other adaptations known to those skilled in the art can alternatively be employed.
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A brace for an archery bow is provided which safely keeps the bow in a cocked position for an extended period of time without fatigue. The brace has a front leg, a middle leg, a rear leg. In the cocked position, the brace legs are selectively prevented from pivoting longitudinally by first and second pivot stops. The coordination of the relative angles between the front, middle and rear brace legs provides the brace with stability to withstand the tension of shooting an arrow.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to spring biased vehicle closure hinges having a laterally coiled spring in integral construction with a link assembly having a reduced footprint for improved packaging in restricted areas, for example, the peripheral channel adjacent to a vehicle opening such as a rear trunk compartment.
2. Background Art
Many previously known vehicle closure hinges such as those used for engine compartment hoods and trunk lids often include spring biasing to assist displacement of the heavy panel which is displaced about a pivot axis at one end of the panel. However, a spring biasing assist force sufficient to maintain the closure in a fully open position is often provided by additional structure such as a prop rod, gas struts or the like to resist closure of the closure panel by the weight of the panel acting in a moment arm about the pivot axis or force transfer through a linkage.
One method to increase the spring biasing has been to use the torsion rods that can be routed across the car. However, while such spring biasing can be strong enough to resist closure, since the entire length of the torsion rod provides spring biasing force, the elongated torsion rods can obstruct and form a substantial impediment to the access through the opening or within the compartment covered by the closure panel. Other improvements to spring design, such as gas powered struts or powerful springs often require multiple installation steps since the spring biasing force unit must be separately installed to assist a conventional hinge structure. Such improvements substantially increase the difficulty of production, rendering the use of such components prohibitively expensive because they add production steps as well as additional pieces and mass to the vehicle. In the case of a gas strut power source, in a closed position the line up force in the strut is directed to the hinge pivot, thus forcing the pivot to endure high loading that shortens useful life of the original installation. Also, the life of a gas strut is both time-dependent and cycle-dependent, making it much less durable than a steel spring.
Moreover, once the spring force has been determined for a particular application, the hinge designs may not be readily incorporated into other vehicles having differently sized, weighted or balanced mass or center of gravity than the installation for which it was designed. As a result, the alternative assemblies may need redesigned linkage and/or biasing structures for each particular closure panel type, thereby substantially multiplying the number of assemblies and production pieces that must be made and inventoried in order to accommodate production and repair of the vehicles despite similar hinge needs and arrangements in the various openings of different vehicle styles.
A previously known attempt to address the problems discussed above involves the use of a single pivot arm as part of a four bar link assembly and integral clock spring. However, while the clock spring may provide substantial flexibility in the design and spring biasing force applied to a hinge mechanism, such springs require an extremely large envelope vertically as well as fore-and-aft to accommodate the four bar linkage and the coil spring. Moreover, the previous designs of this type have been complex requiring numerous parts and assembly operations, the addition of parts rendering the hinge relatively heavy, and thus have not found favor in many production applications due to the large expense compared to more conventional systems.
SUMMARY OF THE INVENTION
The present invention overcomes the above-mentioned disadvantages by providing a reduced footprint hinge construction for vehicle closure by combining a laterally coiled spring with a Watt 6 bar linkage that provides large travel displacement of the vehicle closure from closed to open position with spring biasing. The linkage resists lift-off of the leading edge or pivoted edge of the closure by rotating the deck lid about the leading edge location for a significant percentage of motion along the displacement path. Such linkage prevents the pivoted edge from being pushed off its seal by the forces of the coil spring when the closure is in its closed position.
In the preferred embodiment, the six bar linkage and integral spring combination is mounted in a structural gutter peripherally formed around the opening in the vehicle body. The complexity of manufacturing the various links in the linkage is reduced by matching the design of at least two of the bars in the six bar link so that separate tooling for manufacturing each link is not required. Moreover, the packaging size of the spring may be modified by shaping the cross-section of the strand forming the coil as well as by modifying the number of coils, the diameter of the coils and the thickness of the strand. As a result, the present invention provides a method for reducing the footprint in a manner that is particularly well adapted for mounting the mechanism in the peripheral gutter of a vehicle body compartment such as a trunk.
As a result, the present invention provides a method and apparatus for reducing packaging requirements for the vehicle closure hinge and providing it with spring biasing assist for opening and maintaining the open position of the closure. In particular, the mechanism can be designed to support the closure in a fully open position without external gas filled struts, prop rods or the like that would otherwise need to be packaged in the vehicle. Moreover, the vehicle closure hinge is not subject to performance variation under changing ambient conditions and weather, eliminates lift-off of the leading edge of the closure when in its closed position, and avoids obstruction of both the vehicle opening and the compartment accessed through the opening.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood by reference to the following detailed description of the preferred embodiment when read in conjunction with the accompanying drawing, in which like reference characters refer to like parts throughout the views, in which:
FIG. 1 is a perspective view of a portion of a vehicle body with the closure mounted by a hinge assembly with integral spring constructed according to the present invention;
FIG. 2 is an opposing perspective view similar to FIG. 1 and also showing the hinge in its open position;
FIG. 3 is an enlarged perspective view of a portion of the device shown in FIG. 2 ;
FIG. 4 is an enlarged perspective view of portion of FIG. 1 ;
FIG. 5 is an enlarged perspective view similar to FIG. 4 but showing the hinge in its closed position;
FIG. 6 is an enlarged perspective view similar to FIG. 3 but showing the hinge in its closed position; and
FIG. 7 is an enlarged, partially section view of a portion of the assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1 , a vehicle body 12 is as shown including a vehicle closure panel 14 , such as a deck lid panel, adapted to close over an opening 18 in a body structure 16 , the opening 18 providing access to a compartment 20 formed within the body structure 16 . The closure panel 14 is secured at one end by a hinge mechanism 22 comprising a pair of hinge sets 24 mounted at spaced positions on a panel 14 near a leading or pivot edge 26 . The opposite, trailing, or latch edge of the panel 14 include a latch mechanism for latching the panel 14 in the closed position over the opening 18 in a well-known manner.
In the preferred embodiment, the opening 18 is peripherally defined by a sheet metal structure 16 formed as a gutter trough 28 . The peripheral gutter 28 adds strength to the body structure 16 adjacent the opening as well as a rain trough for controlled routing of rain water for draining. In the preferred embodiment, obstruction of the access opening 18 and the compartment 20 is minimized by locating each of the hinge sets 24 in the gutter 28 .
In the preferred embodiment, each hinge set 24 includes a Watt 6 bar link A 98 assembly 25 integrally constructed with a laterally coiled spring 102 for biasing members of the link assembly 25 to raise the panel 14 to its open position as shown in FIGS. 1 and 2 and described in greater detail below. The selection of a Watt 6 bar linkage is appropriate where wide open position or large range of motion is desired, although other linkage isomers and isomer variations may be selected without departing from the method of the present invention.
As best shown in FIG. 1 , the gutter 28 includes an expanded corner area receiving linkage assembly 30 , the integral combination of link assembly 25 and spring 102 . The assembly 30 is preferably coupled at one edge of the gutter, to allow a laterally coiled spring 102 extending outwardly from the assembly. The diameter of the coils, the number of coils and the thickness of the strand of the coil can be adjusted as desired to ensure sufficient torsion characteristics to operate the link assembly 30 . In addition, as shown in FIG. 7 , the shape of the strand may be modified to enhance or otherwise adjust the strength of the spring without changing size of the envelope. For example, the strength within the package may be maximized without expanding the envelope by shaping the strand as shown in FIG. 7 as rectangular in cross-section so that the radial width of the material in the coil is maximized for strength where the diameter of the coils or the number of coils or both must be limited for example, to fit within the gutter area.
Referring now to FIGS. 3 and 4 , the link assembly 30 includes a body mount bar 32 having mounting flanges 34 and 36 that receive fasteners such as the bolts 38 ( FIG. 4 ) shown in FIG. 1 . The bar 32 also includes spaced pivot pin anchors 39 and 40 adapted to receive pivot pins 42 and 44 , respectively.
The link assembly 30 also includes a closure mount bracket 46 with spaced mounting lands 48 and 50 ( FIG. 3 ) for receiving mounting fasteners 52 and 54 , respectively, as shown in FIG. 1 . A link flange 56 on the closure mount 46 includes pivot supports 58 and 60 adapted to receive pivot pins 62 and 64 , respectively.
The pivot pins 62 and 64 are preferably formed as rivets so as to pivotally engage an anchor for links 66 and 68 , respectively. Pivoted end 70 of the link 66 is spaced apart from an opening receiving a pivot pin 72 , that similarly engages and permits pivotal movement between the link 66 and the end 74 of a pivot link 76 . The link 76 includes a pivot land 78 spaced from the pivot end 74 between the end 74 and the opposite end 80 . The pivot land 78 is adapted to receive a pivot pin 82 while the pivot end 80 receives a pivot pin 44 at the pivot land 40 . The pivot pin 82 is secured to pivotally secure intermediate portions of the link 68 and the link 76 together. Second pivoted end 84 of the link 68 is pivotally engaged with a pivot land 86 on a link member 88 by pivot pin 85 . The other end of the link member 88 includes a pivot land 90 (shown in hidden line in FIG. 6 ) receiving the pivot pin 42 engaged in the body mount 32 .
Preferably, the link member 66 and the link member 88 are formed from the same tooling so that two pieces of the link can be made without unduly increasing the cost of making the numerous links of the link assembly 25 and integral assembly 30 . Accordingly, the land 74 remains unused in the link 88 whereas the land 86 remains unused in the link 66 . Moreover, both members 66 and 88 include an extended end portion 96 opposite the end portion 70 , adapted to support the stem 92 carrying a bumper 94 positioned to press against the edge of the link member 76 when the linkage 25 is extended to the open position of the closure panel. Preferably, the stem is threaded and threadably engaged in the end 96 of the link 66 so that the distance from the bumper can be adjusted to adjust the open position of the hinge. Of course, the end 96 remains unused in the piece used as link 88 in the mechanism 25 . In addition, the link 88 carries a tab 98 that can be wrapped to capture end of the coil spring 102 as shown at 100 in FIGS. 4 and 6 .
The link assembly 25 is biased by attaching a laterally coiled spring 102 formed from the single strand of material, for example steel, wrapped so that the coils are adjacent to each other and extend laterally from one coil end to a second coil end. The strand positioned at the second coil end is then extended in the direction along the axis of the coil toward the first end, preferably through the center of the coil. While the first end of the coil spring 102 adjacent the body mount 36 is wrapped in the flange 106 , ( FIG. 4 ) between the mounting lands 32 and 34 on the mount member 36 , the second end of the strand returned toward the first end of the coil by a strand portion 103 ( FIG. 4 ) extending across the coil, is then wrapped in a curled flange 100 formed by the tab 98 . The coils in the spring 102 therefore impose spring biasing force between the end 108 and the end 104 substantially in the plane of displacement defined by the pivot pins 42 , 44 , 62 , 64 , 72 , 82 and 85 of the assembly 25 .
The vehicle closure hinge provides closure opening torque between the body closure bracket 46 and the body mount 36 , and the center of rotation of the drive link in this case link 88 , is positioned so that maximum room is allowed in the gutter for the largest possible spring. Moreover, the spring force can be adjusted as necessary to adjust for different masses and centers of gravity of closures, preferably by adjusting only dimensions of the structure of the spring, such as the diameter of coil or the number of coils in the winding, the size of the strand, and even adjusting the material mass of the spring by shaping the strand within fixed packaging size. In addition, the manufacturing cost is reduced despite the multiple bar construction of the link assembly, particularly where A single bar design can be used in two different locations within the multiple link assembly. Moreover, the spring assist component is integral with the hinge assembly and substantially reduces the package size and footprint of the hinge mechanism. Accordingly, the present invention provides additional functionality with less obstruction of vehicle compartments or the opening providing access to the compartment. The invention also reduces the number of components to be assembled into the vehicle by providing a single integral unit with a wide range of motion for the closure.
Having thus described the present invention, many modifications will become apparent to those skilled in the art to which it pertains without departing from the scope and spirit of the present invention as defined in the appended claims.
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A link assembly forming a 6 bar linkage is integrally combined with a spring having a laterally coiled strand to form a hinge that is particularly well adapted to be installed in a small footprint. Such a unit is well adapted for installation within a peripheral channel of a vehicle body opening and to prop the closure in its open position. The present invention also provides a method for reducing packaging footprint of a vehicle closure hinge by integrating the 6 bar linkage with the laterally coiled strand, and selecting a strand shaping to reduce radial dimension of the coil and the coil cross-section while maximizing the radial dimension of material in the strand.
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This invention relates generally to rotary die cutting of blanks from thin sheets or webs of material such as paper, paper board, cardboard, plastic film, metal foil, sheet metal and the like. More particularly, this invention relates to improved dies for rotary cutting having a pair of rotary die cylinders, and a blade-carrying die segment mounted on at least one of the die cylinders in axially and/or circumferentially adjusted position.
BACKGROUND
According to present practice as exemplified in U.S. Pat. No. 4,608,895, a web of material is cut along a predetermined line of severance by a pair of superimposed die cylinders having co-acting severing blades in the form of lands projecting generally radially outwardly from the main body of the cylinders. The lands have an outer face and a pair of spaced apart side faces. A cutting edge is defined by the outer face and one side face of each land. To enable adjustment of the lands on one die with respect to the lands on the other die into correct registration for co-acting to cut the web, the lands are constructed and arranged on the dies so that registration can be established by moving the die cylinders axially and/or in rotary phase relationship with respect to each other.
To permit this adjustment where the line of severance defines a closed figure or blank, the cutting action of the lands transfers from one edge to the other at least twice in two generally opposed pairs of cross-over sections in the co-acting lands. If, for example, the blank cut from a web is rectangular, and because of the transfer of the cutting action at the cross-over sections, the lands of each cylinder involved in cutting two axially spaced edges of the figure will be on the same side of the line of severance, and the lands of each cylinder involved in cutting the two circumferentially spaced edges of the figure will also be on the same side of the line of severance.
SUMMARY
Often a closed figure or blank is cut to provide tabs or openings or lines of perforations inside the boundary of the blank. In such cases, the lands on the die cylinders providing the co-acting cutting edges for making these inside cuts sometimes are constructed and arranged such that when the die cylinders are moved axially and/or in rotary phase relationship with respect to each other for correct registration of the lands which cut the line of severance defining the boundary of the blank, the lands having the edges performing the inside cuts actually move out of proper registration. In other words, the die cylinders might be moved axially and/or circumferentially relative to each other to bring closer together the lands having the co-acting edges for cutting the boundary line severance for the blank, but such relative movement of the die cylinders might at the same time move farther apart the lands having the cutting edges for making the inside cuts. The reasons for the non-conforming construction and arrangement of the lands having the cutting edges for the inside cuts may vary, but one reason is that the high speed stacking of blanks leaving the die cylinders requires that the slightly bent edges defining an inside cut must be inclined in a direction which facilitates the sliding of the blanks onto the stack without hang-ups or jamming.
Objects, features and advantages of this invention are to provide a pair of rotary die cylinders which can be readily and easily adjusted for proper registration or co-action of all of their cutting edges, including the edges for making cuts inside the boundary of a blank, have adjustable die segments on one or both of the die cylinders for carrying lands having at least some of the cutting edges, will decrease the tendency for cut blanks to hang up or snag when stacked, and to provide rotary die cylinders which can be economically manufactured and are rugged and durable.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the invention will be apparent from the following detailed description, appended claims and accompanying drawings in which:
FIG. 1 is a perspective view of rotary dies having adjustable cutting segments, in accordance with the invention;
FIG. 2 is a semi-diagrammatic elevational view of the rotary dies, but for purposes of clarity, omitting the co-acting cutting lands, partially showing the lines of severance of closed figures or blanks to be cut from a web of material, showing die segments for making cuts within the boundaries of the blanks, and also showing the lines produced by the cutting edges of the lands on the die segments;
FIG. 3 is an enlargement of a portion of FIG. 2 showing one of the die segments but omitting the cutting blades for clarity;
FIG. 4 is a sectional view taken on the line 4--4 in FIG. 3;
FIG. 5 is a sectional view taken on the line 5--5 in FIG. 3;
FIG. 6 is a fragmentary elevational view of a portion of FIG. 4;
FIG. 7 is an enlargement of a portion of FIG. 2 showing the other die segment but omitting the cutting blades for clarity;
FIG. 8 is a fragmentary sectional view taken on the line 8--8 in FIG. 7;
FIG. 9 is a fragmentary sectional view taken on the line 9--9 in FIG. 7;
FIG. 10 is a view in elevation showing a portion in FIG. 8;
FIG. 11 is a sectional view taken on the line 11--11 in FIG. 7;
FIG. 12 is an enlarged semi-diagrammatic view showing the two die cylinders with a die segment mounted on one of the die cylinders, prior to adjustment of the cutting edges of the lands;
FIG. 13 is similar to FIG. 12 but after adjustment; and
FIGS. 14 and 15 are illustrative of the prior art, showing the positions of the lands before and after adjustment.
DETAILED DESCRIPTION
Referring now more particularly to the drawings, FIG. 1 is a perspective view illustrating a pair of rotary die cylinders 10 and 12 of this invention for cutting rectangular articles or blanks 14 from a web 16 of material passing between the dies. The material is cut by the edges of co-acting blades or lands 18 and 20 of the dies. Preferably the die cylinders are in the form of cylindrical bodies and have a plurality of pairs of co-acting lands on the cylindrical surface thereof which are equally spaced apart circumferentially. The die cylinders are journalled for rotation by shafts 22 and 24 which preferably are formed integrally with the dies. The dies are co-rotated in opposite directions of rotation at the same speed by a pair of meshed gears 26 each coupled to one of the shafts of the dies. Die cylinder 10 has a recess 28 in its cylindrical surface in which a die segment 30 is mounted. Die cylinder 12 has a recess 32 in its cylindrical surface in which a die segment 34 is mounted. The die segments have lands 36 and 37 provided with cutting edges for co-acting with similar cutting edges on lands 36' & 37' on the other die cylinder to form cuts within the outline of the blanks to provide lines of perforations or the like.
FIG. 2 shows the die cylinders 10 and 12 but, for clarity, omits the cutting blades or lands. However, in FIG. 2 there is partially shown the lines of severance 29 and 33 of the omitted lands on the die cylinders for cutting blanks (of different outline than the blank which would be cut by the lands 18 and 20 in FIG. 1), and also the lines of severance 35 and 39 of the omitted lands on the die segments and on one of the die cylinders.
The recess 28 for the die segment 30 is rectangular and elongated circumferentially, with a flat bottom surface 38 disposed in a plane parallel to the axis of rotation of the die cylinder. The die segment 30 is an elongated bar disposed lengthwise within the recess, having a flat bottom 40 slidably supported on the bottom surface 38 of the recess and a top surface 42 circumferentially curved to conform to the curvature of the die cylinder. The recess 28 is wider than the die segment 30 as seen in FIG. 3. To permit axial adjustment of the die segment, an elongated axially extending key 44 projects upwardly through the bottom of the recess 28 and is slidably received in an axially extending slot 46 across the bottom of the die segment. The key permits the die segment to be adjusted only in an axial direction.
The die segment 30 is releasably secured in adjusted position by bolts 47 extending through enlarged openings 49 in the die segment and threading into the die cylinder. The openings 49 are counterbored to received the bolt heads 51 which bear against the bottom 53 of the counterbores to clamp the die segment when the bolts are tightened.
When bolts 47 are loosened, die segment 30 may be shifted axially by a rotary adjustment member or stud 48 which extends through an opening 50 in the die segment and is rotatably received in a hole 52 in the bottom of the recess. The opening is enlarged to provide an oval-shaped portion 54 at the bottom, the circumferentially spaced sides of which are more closely spaced than the axially spaced sides. The stud 48 has a circular cam 56 disposed within the oval-shaped portion 54 and has a diameter equal to the minor diameter of the oval-shaped portion. The cam 56 is eccentric with respect to the rotational axis of the stud 48 so that when the stud is rotated, the cam 56 shifts the die segment 30 axially with respect to the die cylinder 10. The head 58 of the stud has a transverse slot 60 and may be rotated by a screw driver 62 or the like to axially adjust the die segment. The top of the enlarged oval-shaped portion 54 provides a shoulder 64 overlying the cam to prevent the stud from becoming separated from the die segment. Indicia 63 on the stud head and on the die cylinder mark the rotational position of the stud.
Tapped holes 65 in the die segment 30 are adapted to threadedly receive threaded lifting elements (not shown) to enable the die segment to be lifted from recess 28.
The recess 32 for the die segment 34 is rectangular and elongated axially and has a flat bottom surface 66 disposed in a plane parallel to the axis of rotation of the die cylinder. A plate or spacer 68 affixed by any suitable means to the bottom surface of the recess has a circumferentially extending top surface 70, the axis of which coincides with the axis of rotation of the die cylinder. The die segment 34 is an elongated bar disposed lengthwise within the recess 32 having a circumferentially extending bottom surface curved on the same radius as the top surface 70 of the spacer so as to have a flush surface-to-surface sliding engagement therewith. The top surface 72 of the die segment 34 is curved to conform with the cylindrical surface of the die cylinder 12. The recess 32 is wider than the die segment 34 as seen in FIG. 9. To permit circumferential adjustment of the die segment 34, an elongated circumferentially extending key 74 projects upwardly through the spacer 68 and is slidably received in a circumferentially extending slot 76 across the bottom of the die segment. The key 74 permits the die segment 34 to be adjusted only in a circumferential direction.
The die segment 34 is releasably secured in adjusted position by bolts 78 extending through enlarged openings 80 in the die segment and threading into the die cylinder. The openings 80 are counterbored to receive the bolt heads 82 which bear against the bottoms 84 of the counterbores to clamp the die segment when the bolts are tightened.
When bolts 78 are loosened, die segment 34 may be shifted circumferentially by a rotary adjustment member or stud 86 which extends through an opening 88 in the die segment 34 and is rotatably received in a hole 90 in the bottom of the recess. The opening 88 is enlarged to provide an oval-shaped portion 92 at the bottom, the axially spaced sides of which are more closely spaced than the circumferentially spaced sides. The stud 86 has a circular cam 94 disposed within the oval-shaped portion 92 and has a diameter equal to the minor diameter of the oval-shaped portion. The cam 94 is eccentric with respect to the rotational axis of the stud 86 so that when the stud is rotated, the cam 94 shifts the die segment 34 circumferentially with respect to the die cylinder 12. The head 98 of the stud has a transverse slot 100 and may be rotated by a screw driver or the like to circumferentially adjust the die segment 34. Indicia 104 on the stud head and on the die cylinder mark the rotational position of the stud.
The tapped holes 103 in the die segment 34 are adapted to threadedly receive threaded lifting elements (not shown) to enable the die segment to be lifted from the recess.
Referring now to FIGS. 14 and 15 which are illustrative of the prior art, die cylinders 10' and 12' are shown, which are like die cylinders 10 and 12 previously described except that neither has a die segment. The lands 18' and 20' on the cylindrical surface of the die cylinders 10' and 12' have cutting edges 118' and 120' which coact to cut a blank from a web of material passing between the rotating die cylinders. The die cylinders also have lands 150' and 152' on the cylindrical surface thereof with cutting edges 154' and 156' for making inside cuts within the margin of the blanks. However, it will be noted in FIGS. 14 and 15 that while the lands 18' on die cylinder 10' are left of the co-acting lands 20' on die cylinder 12', the lands 150' on die cylinder 10' are right of the co-acting lands 152' on die cylinder 12'. As previously stated, it may be necessary in the production of a particular blank, in order to ensure rapid and accurate stacking of blanks delivered at high speed from the die cylinders, that the relationship of the lands and cutting edges for making both the marginal line of severance for the blank as well as those for making inside cuts be constructed and arranged as shown in FIGS. 14 and 15. However, when the die cylinders 10' and 12' are shifted axially relative to each other to establish a proper registration of the cutting edges of lands 18' and 20', as for example, by moving die cylinders 10' rightward to bring the cutting edges 118' and 120' of lands 18 and 20 closer together, the cutting edges 154' and 156' of lands 150' and 152' are moved farther apart. This can be seen in FIGS. 14 and 15 in which FIG. 14 illustrates the relative positions of the lands and cutting edges before axial shifting of die cylinder 10' relative to die cylinder 12' and FIG. 15 illustrates the relative positions of the lands and cutting edges after axial shifting of die cylinder 10' relative to die cylinder 12'. Accordingly, in the prior art it was not always possible to adjust the relative positions of all of the cutting edges by a simple axial movement of one die cylinder relative to the other. Likewise, in prior art constructions, it was not always possible to adjust the relative positions of all of the cutting edges by a simple rotative or circumferential movement of one die cylinder relative to the other.
FIGS. 12 and 13 are illustrative of the present invention in which the lands 18 and 20 on the cylindrical surface of the die cylinders 10 and 12 have cutting edges 118 and 120 which coact to cut a blank from a web of material passing between the rotating die cylinders. However, the lands 36 having the cutting edges 154 which coact with cutting edges 156 of lands 36a on die cylinder 12 for making inside cuts within the margin of the blanks are on the adjustable die segment 30. Therefore, a relative axial shifting of the die cylinders 10 and 12 from the FIG. 12 position to the FIG. 13 position can be effected to properly register the lands 18 and 20 and cutting edges 118 and 120 on the cylindrical surface of the die cylinders, and the die segment 30 may be independently adjusted axially to properly register the lands 36 and 36a and cutting edges 154 and 156. Similarly, the die segment 34 on die cylinder 12 also makes it possible to circumferentially adjust the cutting blades of lands on the die segment independently of the other cutting blades or lands on die cylinder 12.
While in the foregoing, there have been disclosed one blade-carrying die segment capable of axial adjustment only (segment 30) and one blade-carrying die segment capable of circumferential adjustment only, it should be understood that a compound die segment could be employed having a portion capable of axial adjustment and another portion capable of circumferential adjustment.
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Rotary die cylinders for cutting blanks from thin sheets or webs of material. The die cylinders have coacting cutting blades, some of which are carried by die segments mounted on the die cylinders in axially and/or circumferentially adjusted positions.
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FIELD OF THE INVENTION
The present invention relates to a process for the delignification and brightening of lignocellulosic pulp. More particularly, it relates to a material improvement in a lignocellulosic pulp bleaching sequence employing oxygen during the alkaline extraction stage.
BACKGROUND OF THE INVENTION
The conventional method for delignifying and bleaching lignocellulosic pulp has been to employ a variety of multi-stage bleaching sequences, for example, 4, 5, or 6 stages, which traditionally have been based on the use of chlorine and/or chlorine dioxide in the bleaching or brightening stages.
In practice, intermediate alkaline extraction stages with caustic are used between the chlorination and bleaching stages. When applied immediately following the chlorination stage, denoted as CE, the first alkaline extraction stage is used to solubilize and remove a major portion of the chlorinated and oxidized residual lignin (chlorolignin) that is retained in the chlorination stage pulp, remove fatty acid-esters and resins present in the pulp, and also remove hemicellulose. It is an integral part of any multi-stage bleaching sequence. The resultant chlorinated-extracted pulp contains only 0.5% to 1.0% residual lignin which is amenable to further oxidation and brightening in later stages without excessive bleach chemical usage. However, while the alkaline extraction stage prepares pulp for subsequent bleaching, its immediate effect is to darken the remaining pulp impurities relative to chlorinated pulp.
With the advent of stricter environmental regulations designed to abate water and air pollution problems associated with chlorine--containing bleaching chemicals, coupled with their high cost and extensive recovery systems needed for their removal from the effluent streams, the paper industry has directed its attention to other bleaching chemicals which might avoid these problems.
One of the major areas of research and development in the last number of years has been directed to the use of oxygen as a delignifying agent and bleachant in various pulp bleaching sequences. One bleaching innovation that has been widely acclaimed is the use of oxygen in conjunction with a conventional alkaline extraction stage, denoted as Eo, immediately following a chlorination stage. It has achieved widespread commercial implementation in the last number of years. D. W. Reeve in TAPPI: 67(4), 143 (1984) provides a partial tabulation of worldwide Eo installations, and Enz and Hallenbeck presented a detailed description of the effects an Eo-stage has on bleach plant operations and pulp quality (1983 Pulping Conference, Houston, Tex., November 1983, pp. 309-313).
The principle action of oxygen in an alkaline extraction stage is to partially delignify and brighten the pulp compared to a conventional non-oxygen reinforced caustic extraction. Typically, in mill practice, the lignin content of the pulp is decreased by 18-25% of the lignin normally remaining in a conventional softwood kraft pulp subsequent to a CE treatment, as measured by Tappi standard method T214. In the case of hardwood kraft pulps, the delignification usually does not exceed a 15-20% decrease in lignin content when compared with a conventional CE bleached pulp. The brightness of both softwood and hardwood pulps is increased by about 4-6% GE points when an oxygenated alkaline extraction stage is employed compared to an alkaline extraction stage in which oxygen is not used.
While the use of oxygen in an alkaline extraction stage materially increases delignification and brightness, it adversely affects pulp viscosity which represents a drawback to its use. Typically, a softwood or hardwood kraft pulp extracted in the presence of oxygen has a viscosity which is 2-3 cps lower than a pulp which has been conventionally extracted.
Accordingly, it is an object of the present invention to provide a method for increasing the amount of delignification and brightening provided by an oxygen-alkaline extraction stage (Eo) without incurring additional viscosity losses.
SUMMARY OF THE INVENTION
The foregoing object, and other objects which will be apparent to those skilled in the art, is accomplished by adding a hypochlorite or a peroxide together with oxygen during the first alkaline extraction stage with caustic of a multi-stage bleaching and delignification process, or by adding a hypochlorite or a peroxide directly to the pulp immediately prior to the first alkaline extraction stage with caustic and oxygen in a multi-stage bleaching and delignification process. For the purposes of this specification and the appended claims, the alternate modes of addition of hypochlorite or peroxide which are described above, and which shall be described hereinafter in greater detail, shall be deemed to be equivalent and comprise but a single stage, namely, the first alkaline extraction stage in a multi-stage bleaching and delignification process.
The process of the present invention has a number of advantages over the practices of the prior art. It provides additional delignification and brightening in an extraction stage beyond that attainable by either C D (hE), C D (pE) or C D E o alone and, most unexpectedly, without any additional loss in viscosity beyond that obtained when using any of the foregoing sequences at comparable permanganate numbers. As used herein, (hE) is used to denote the use of hypochlorite followed by an alkaline extraction without an intervening washing stage. Similarly, the use of (pE) herein is to denote the use of peroxide followed by an alkaline extraction without an intervening washing stage.
This is especially noteworthy with regard to hypochlorite since it is not considered to be a lignin-specific bleaching agent and its use always results in some attack on cellulose regardless of the pH. Moreover, the use of hypochlorite or peroxide in the first alkaline extraction stage is regarded as being an ineffective means of bleaching pulp fiber compared to its use in subsequent bleaching stages. Furthermore, the process of the present invention also serves to reduce hypochlorite or chlorine-dioxide usage downstream in the bleaching process and thus effect a significant saving in chemical usage.
While not wishing to be bound or limited by any theory, it is postulated that either: (1) the hypochlorite or the peroxide activate the chlorolignins in the pulp thereby rendering them more amenable to further bleaching without attacking the cellulosic portion of the pulp; or (2) there is an unknown reaction between the hypochlorite or peroxide and oxygen which is lignin selective and thus minimizes damage to the cellulosic portion of the pulp.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the process of the present invention, an aqueous northern or southern hardwood or softwood kraft pulp may be employed. While it is preferred to employ a kraft pulp, other chemically digested pulps may be used, such as soda, sulfite, semi-chemical, soda-anthraquinone, etc. The consistency of the pulp can be from about 0.1% to about 30%, based on the oven-dry weight of the pulp. A consistency of from about 1% to about 15% is preferred, with a consistency of from about 3% to about 12% being especially preferred.
Typically, in the first or initial delignification and bleaching stage subsequent to digestion, the pulp is first chlorinated, using either chlorine, chlorine dioxide, or a mixture of chlorine and chlorine dioxide, at a temperature of from about 30° C. to about 75° C. for about 1 minute to about 60 minutes. The consistency of the pulp after chlorination can be from about 1% to about 10%. Alternatively, in the first bleaching stage the pulp can also be treated with ozone, oxygen or with acid peroxide. Further, in accordance with the process of the present invention the bleaching and delignification chemicals listed above can also be used alone or in various combinations, if it is so desired, in one or more stages following the initial stage, provided that the initial extraction stage is operated in accordance with the process of the present invention.
Thereafter, the pulp is washed using a drum washer or other suitable washing apparatus, steamed in a steam mixer, and subjected to a first alkaline extraction with caustic, preferably sodium hydroxide, or other suitable alkaline extractants such as potassium hydroxide or sodium carbonate, at a consistency of from about 3% to about 15%, based on O.D. weight of the pulp, at a temperature between about 40° C. and about 80° C., for a retention period of from about 3 minutes to about 120 minutes, using a quantity of sodium hydroxide corresponding to a % sodium hydroxide to % chlorine ratio, based on the oven-dry weight of the pulp, of between about 0.35 and about 0.65.
In accordance with the process of the present invention, from about 0.2% to about 1.0% of oxygen, based on the oven-dry (O.D.) weight of the pulp, is added during the alkaline extraction stage. It is preferred to employ from about 0.4% to about 0.6% oxygen, based on O.D. pulp. Simultaneous with the addition of the oxygen, either sodium hypochlorite or calcium hypochlorite, or alternatively hydrogen peroxide, sodium peroxide, other inorganic peroxides, or organic peroxides, or compounds which in situ produce peroxides, is added during the alkaline extraction stage.
It is preferred to employ either sodium hypochlorite or hydrogen peroxide at an application level of from about 0.05% to about 1.0%, based on O.D. pulp, and preferably, at an application level of from about 0.05% to about 0.5%, based on O.D. pulp.
Such an addition results in delignification and brightening benefits which are greater than when either oxygen or sodium hypochlorite, or oxygen and hydrogen peroxide, are used separately. In other words, as will be seen by reference to the experimental results reported in the examples which follow, an unanticipated synergistic effect is observed. And, furthermore, in the case of sodium hypochlorite no additional viscosity losses are incurred over the use of an oxygen alkaline extraction stage.
The oxygen and the sodium hypochlorite, or the oxygen and the hydrogen peroxide, can be incorporated into the pulp by one of several means, including a high shear mixer, a static mixer, a refiner or a medium consistency pump.
The alkaline extraction stage can take place in a conventional tower used for extraction or in a pressurized vessel such as a digester, and it can be conducted under a constantly declining pressure head, as disclosed by Roymoulik and Brown in U.S. Pat. No. 3,832,276, the disclosure of which is incorporated herein by reference, or by applying a constant partial pressure of oxygen to the pulp.
Alternatively, the sodium hypochlorite or the hydrogen peroxide can be added immediately prior to the oxygen-alkaline extraction stage. In this mode, the sodium hypochlorite or hydrogen peroxide is conveniently added at the repulper, at the last shower bar of the chlorination stage washer or at any other convenient location prior to the addition of oxygen, and the pulp residence time in the steam mixer is from less than about one minute to about three minutes or somewhat more. Furthermore, in this mode of addition a portion, but not all, of the sodium hypochlorite or hydrogen peroxide applied is consumed before the oxygen-alkaline extraction stage and thus sodium hypochlorite or hydrogen peroxide, as such, is present during the extraction per se.
After completion of the extraction stage, the pulp is washed and then bleached further by any of a variety of sequences having one or more stages. The number and type of stages employed subsequent to extraction are dependent upon whether the pulp is a hardwood or a softwood, the brightness level which is desired to be attained, and the type and amount of bleachant chemicals employed. Exemplary post-extraction stages sequence are: D, DED, (hD), HD, HDED or (hD)ED. It has been shown experimentally, as will be seen hereafter by reference to Examples 2 and 3, that employing a separate hypochlorite stage after the extraction stage is particularly advantageous when bleaching hardwood pulp.
In order to disclose more clearly the nature of the present invention, the following examples illustrating the invention are given. It should be understood, however, that this is done solely by way of example, and is intended neither to delineate the scope of the invention nor limit the ambit of the appended claims.
EXAMPLE 1
A typical southern softwood kraft pulp (4×1200 oven dry grams,), with an initial lignin content expressed in Kappa number units corresponding to 34.3, was chlorinated with a mixture containing 7.64% chlorine, 0.22% chlorine dioxide, and sufficient water to provide a final consistency corresponding to 3.0%. The chlorination stage was performed at 40° C. for 40 minutes. Subsequently, each of the four portions was thoroughly washed, pressed to a consistency of approximately 30% solids, and comminuted into fiber and fiber aggregates.
The first portion (henceforth C D E pulp) was diluted with water and sufficient 1.0N sodium hydroxide solution to provide a final consistency corresponding to 10% solids and an amount of sodium hydroxide corresponding to 3.29% of the total oven dry weight of pulp. The pulp mixture was charged into a 10 gallon Pfaudler reactor, heated to 70° C., mixed with mechanical agitation, and held at 70° C. for 60 minutes. At the end of one hour the pulp was diluted to less than 1% consistency, drained, rediluted to less than 1% consistency, and pressed to approximately 30% solids.
The second portion (henceforth C D (hE)) was treated similarly to the C D E variant above, except that 3.39% sodium hydroxide and 0.3% sodium hypochlorite (calculated on an active chlorine basis) were used.
The third portion (henceforth C D E o pulp) was treated similarly to the C D E variant except that 3.39% sodium hydroxide was used and an initial pressure of 40 psig gaseous oxygen was applied. Also, the C D E o variant was treated in such a manner that a pressure relief schedule corresponding to a 4 psig drop every 6 minutes was followed in order to simulate upward flow in a commercial extraction stage as carried out in a conventional upflow extraction tower.
Last, the fourth portion of chlorinated pulp (henceforth C D (hE o ) pulp) was treated similarly to the C D E o variant, including the pressure relief schedule, except that both 40 psig gaseous oxygen and 0.3% sodium hypochlorite were applyed simultaneous with the sodium hydroxide/water solution.
TABLE 1______________________________________ Permanganate % GE 0.5% CEDVariant No. Brightness Viscosity______________________________________C.sub.D E 3.62 33.8 30.9C.sub.D (hE) 3.47 34.5 30.8C.sub.D E.sub.o 3.07 37.4 29.3C.sub.D (hE.sub.o) 2.85 39.0 29.4______________________________________
Table 1 depicts the results of the analyses on the aforementioned variants from which it is apparent that the C D (hE) sequence produces a small but measurable decrease in lignin content and an increase in brightness compared to C D E pulp. Similarly, the C D E o process yields pulp having greater delignification and brightening than C D (hE) pulp, and much lower lignin content and greater brightness than that of C D E pulp. Also, it is apparent that in both cases, C D E o and C D (hE), pulp viscosity is decreased by small but measurable amounts compared to the conventional C D E pulp viscosity. However, the results of the C D (hE o ) experiment clearly indicate that the combined effects of oxygen and sodium hypochlorite in the first extraction stage exceed those found for either of the individual treatments, and exceed that which is predictable by the simple additive effects of either C D (hE) or C D E o .
For example, the use of 0.3% sodium hypochlorite alone, i.e., C D (hE), resulted in pulp having a permanganate number and brightness corresponding to 3.47 and 34.5% GE, respectively; these amount to a 4.1% decrease in lignin content and a 0.70% increase in brightness, respectively, compared to CE-pulp. In the case of C D E o -pulp, the degree of delignification and brightening compared to CE-pulp amounts to 15.2% and 3.6% GE, respectively. However, in the case of C D (hE o ) pulp, delignification and brightening amounted to 21.3% and 5.2% GE, respectively, which exceeds the sum of the results from (hE) and E o , namely, 21.3% vs 15.2%+4.1% and 5.2% GE vs 3.6% GE+0.70% GE). Moreover, the C D (hE o ) pulp viscosity of 29.4 cps reflected an improved viscosity over the 29.3 cps in C D E o sequence.
EXAMPLE 2
A typical southern hardwood kraft pulp (1475 od grams) having a lignin content corresponding to 16.5 Kappa, was chlorinated with a mixture containing 3.14% chlorine and 0.1% chlorine dioxide at 40° C. and 3% consistency for 40 minutes. Subsequently, the chlorinated pulp was washed thoroughly, pressed to a consistency of approximately 30% solids, comminuted to fiber and fiber aggregates and divided into four equal portions, denoted as A, B, C and D.
Portion A was diluted with water and sufficient sodium hydroxide to provide a final consistency corresponding to 10% solids and an amount of sodium hydroxide corresponding to 1.41% of the total oven-dry weight of pulp. The pulp mixture was charged into a 10 gallon Pfaudler reactor, pressurized with gaseous nitrogen to 40 psig to simulate the hydrostatic head pressure of an extraction tower 80 feet in height, heated to 70° C., with mechanical agitation, and held at this temperature for a period of one hour. During the prescribed retention time, a pressure relief schedule amounting to a 4 psig decrease every 6 minutes was followed in order to simulate upward pulp flow in a commercial extraction stage. At the end of one hour, as measured from the time when the temperature reached 70° C. and the pressure reached 40 psig, the pulp was diluted to less than 1% consistency, drained, rediluted to less than 1% consistency, and pressed to approximately 30% solids.
Portion B was treated similarly to Portion A, except that 0.4% sodium hypochlorite (as calculated on an active chlorine basis) was included in the sodium hydroxide-water mixture.
Portion C was treated similarly to Portion A, except that gaseous oxygen was substituted for nitrogen.
Portion D was treated similarly to Portion C, except that 0.4% sodium hypochlorite was also included. For convenience, Portions A, B, C and D will be referred to as C D E, C D (hE), C D E o and C D (hE o ), respectively.
TABLE 2______________________________________ C.sub.D E C.sub.D (hE) C.sub.D E.sub.o C.sub.D (hE.sub.o)______________________________________Tappi P No. 2.64 2.43 2.32 2.11GE Brightness 36.8 41.4 40.8 45.7Viscosity 19.7 19.6 19.0 19.0______________________________________
From Table 2 above it is readily apparent that of the four pulps described the C D (hE o ) variant has the lowest permanganate number, highest brightness and a viscosity which is equivalent to that of its C D E o counterpart. In this case brightness increased and the prevention of viscosity loss improved to an extent which would not be predictable from individual brightness increases and viscosity losses of the C D (hE) or C D E o pulps.
TABLE 3__________________________________________________________________________Post Extraction Hypochlorite Stage TrialsC.sub.D E C.sub.D (hE) C.sub.D E.sub.o C.sub.D (hE.sub.o)__________________________________________________________________________% Hypo- 0.7 0.9 1.1 0.6 0.8 1.0 0.5 0.7 0.9 0.3 0.5 0.7chlorite% NaOH 0.25 0.32 0.40 0.225 0.30 0.375 0.25 0.30 0.38 0.20 0.25 0.30pH Off 8.9 9.1 9.7 9.5 9.5 9.8 9.4 9.5 9.6 9.7 9.5 9.3GE Bright- 64 68 71 65 69 72 62 68 72 59 66 71nessVisc. (0.5% 16.6 13.6 11.9 16.4 13.4 11.6 17.4 15.9 12.3 18.6 16.6 13.9CED)__________________________________________________________________________
Table 3 points out the benefits to be obtained with a C D (hE o ) bleaching sequence and the advantage it offers over the prior art are especially evident when one considers the results from a post extraction hypochlorite stage, employing sodium hypochlorite and sodium hydroxide, on the four pulps described above.
For example, at roughly equivalent GE brightness (71-72%), the C D (hE o ) variant has higher viscosity than either the C D E, C D (hE) or C D E o variants. The foregoing phenomenon is especially unexpected and surprising since the C D (hE o ) variant used the same total active chlorine (as sodium hypochlorite) to reach 71% GE brightness as did the C D E variant, and a greater quantity of total active chlorine than the C D E o variant, yet the final viscosity is about 1.6 to 2.0 cps greater for C D (hE o ).
EXAMPLE 3
During a period of continuous operation, an unbleached southern hardwood kraft pulp with an average permanganate number and viscosity corresponding to 12.5 and 25.7 cps, respectively, was chlorinated at an average consistency and temperature corresponding to 3.3% and 38° C. using a mixture containing 3.9% chlorine and 0.2% chlorine dioxide based on the oven dry weight of pulp. Subsequently, caustic extraction was performed in a continuous manner at an average consistency and temperature of 11.3% and 64° C. using 2.8% sodium hydroxide. This resulted in a C D E-pulp with the following properties: 3.50 permanganate number, 34% brightness (GE), and 21.2 cps viscosity.
During another period of continuous operation, a southern hardwood kraft pulp similar to that described above, i.e., 13.6 permanganate number and 24.5 cps, was chlorinated and extracted in a similar manner except that an average of 0.4% oxygen was used in the extraction stage. This resulted in C D E o pulp with the following properties: 2.87 permanganate number, 41.6% GE brightness, and 18.1 cps viscosity.
During a third period of continuous operation, a southern hardwood pulp similar to those described previously, i.e. 13.2 permanganate number and 24.9 cps viscosity, was chlorinated and extracted in a manner similar to that described for the C D E o pulp, except that an average of 0.29% sodium hypochlorite was included on the chlorinated pulp at the chlorination washer repulper prior to the E o extraction. This produced a C D (hE o ) pulp with the following properties: 1.96 permanganate number, 47.5% GE brightness, and 18.1 cps viscosity.
Upon subsequent hypochlorination of the three pulps described above in a separate bleaching stage using an average of 1.13% hypochlorite on C D E-pulp, 1.05% on C D E o -pulp and 0.97% on C D (hE o ) pulp, the average pulp properties depicted in Table 4 were observed. The advantages of using the C D (hE o ) process are immediately apparent based on substantial brightness increases and remarkably improved viscosity.
TABLE 4______________________________________ Viscosity,% NaOCl Brightness (GE) cps (0.5% CED)______________________________________C.sub.D E 1.13 68.0 13.8C.sub.D E.sub.o 1.05 69.4 12.9C.sub.D (hE.sub.o) 0.97 73.5 13.9______________________________________
EXAMPLE 4
During a period of continuous operation, an unbleached southern softwood kraft pulp with an average permanganate number and viscosity corresponding to 22.5 and 29.4 cps, respectively, was chlorinated at an average consistency and temperature corresponding to 3.0% and 33° C. using a mixture containing 8.6% chlorine and 0.1% chlorine dioxide based on the oven dry weight of pulp. Subsequently, caustic extraction was performed in a continuous manner at an average consistency and temperature of 9.9% and 62° C. using 4.5% sodium hydroxide. This resulted in a C D E-pulp with the following properties: 5.31 permanganate number, 24.0% brightness (GE), and 25.0 cps viscosity.
During another period of continuous operation, a southern softwood kraft pulp similar to that described above and having a 22.8 permanganate number and 25.8 cpc viscosity was chlorinated and extracted in a similar manner except that 0.6% oxygen was used in the extraction stage. This resulted in a C D E o pulp with the following properties: 4.47 permanganate number, 26.5% brightness (GE), and 22.8 cps viscosity. During a third period of continuous operation, a southern softwood kraft pulp similar to those described previously and having a 22.9 permanganate number and 25.2 cps viscosity was chlorinated and extracted in a manner similar to the C D E o -process, except that an average of 0.3% hypochlorite was included on the chlorinated pulp at the chlorination washer repulper prior to the E o extraction. This resulted in a C D (hE o ) pulp with the following properties: 3.28 permanganate number, 32.8% brightness, are 22.4 cps viscosity.
For comparison purposes, a sample of pulp was obtained from the system prior to the injection of oxygen and held at constant temperature for a period corresponding to the retention time in the extraction tower, which was approximately 60 minutes. This pulp sample corresponds to the C D (hE) variant and had the following properties: 4.23 permanganate number 26.6% brightness (GE), and 22.6 cps viscosity.
It is apparent that the synergism between hypochlorite and oxygen produced a C D (hE o ) pulp with delignification and brightness greater than that which would be expected from the individual effects of E o and (hE), which demonstrates convincingly that the process of the present invention is selective in its removal of lignin without sacrificing viscosity.
TABLE 5______________________________________ % Brightness Viscosity,Permanganate No. (GE) cps (0.5% CED)______________________________________C.sub.D E 5.31 24.0 25.0C.sub.D E.sub.o 4.47 26.5 22.8C.sub.D (hE) 4.23 26.6 22.6C.sub.D (hE.sub.o) 3.28 32.8 22.4______________________________________
EXAMPLE 5
A typical northern hardwood kraft pulp (4000 g od) having a lignin content corresponding to 15.4 Kappa, was chlorinated with a mixture containing 2.46% chlorine and 0.1% chlorine dioxide (based on the oven dry weight of pulp), at 45° C. and 1.8% consistency for 30 minutes. Subsequently, the chlorinated pulp was washed thoroughly, pressed to a consistency of approximately 30% solids, comminuted to fiber and fiber aggregates and divided in six equal portions denoted as A, B, C, D, E and F.
Portion A was diluted with water and sufficient sodium hydroxide to provide a final consistency corresponding to 10% solids and an amount of sodium hydroxide corresponding to 1.35% of the total oven-dry weight of pulp. The pulp mixture was charged into a 10 gallon Pfaudler reactor, pressurized with gaseous nitrogen to 45 psig, heated to 65° C., mixed with mechanical agitation, and held at this temperature for a period of 75 minutes. During the prescribed retention time, a pressure relief schedule amounting to 3 psig every minute was imposed resulting in atmospheric pressure within the reactor at the end of 15 minutes. Upon completing the extraction, the pulp was diluted to less than 1% consistency, drained, rediluted to less than 1% consistency, and pressed to approximately 30% solids.
Portion B was treated in a manner similar to Portion A, except that gaseous oxygen was substituted for nitrogen and 1.55% NaOH was applied to the pulp.
Portion C was treated in a manner similar to Portion A, except that 0.4% sodium hypochlorite was included in sodium hydroxide-water mixture, and 1.55% NaOH was applied to the pulp.
Portion D was treated in a manner similar to Portion C, except that gaseous oxygen was substituted for nitrogen.
Portion E was treated in a manner similar to Portion C, except that 0.2% hydrogen peroxide was used instead of sodium hypochlorite.
Portion F was treated in a manner similar to Portion E, except that gaseous oxygen was substituted for nitrogen. For convenience, Portions A through F will be referred to as C D E, C D E o , C D (hE), C D (hE o ), C D (pE) and C D (pE o ), respectively.
TABLE 6__________________________________________________________________________ C.sub.D E C.sub.D E.sub.o C.sub.D (hE) C.sub.D (hE.sub.o) C.sub.D (pE) C.sub.D (pE.sub.o)__________________________________________________________________________Tappi P No. 3.2 2.9 3.1 2.6 3.1 2.4GE Brightness 44.2 47.0 44.5 50.9 48.7 53.3Viscosity 27.7 26.0 25.9 26.7 27.2 24.9__________________________________________________________________________
From Table 6 above it is readily apparent that of the six pulps described, the C D (pE o ) variant has the lowest permanganate number and highest brightness. Furthermore, the increase in brightness and decrease in permanganate number in the C D (pE o ) variant are greater than those produced by E o or (pE) alone, and most significantly and unexpectedly, are greater than that which could be predicted by the additive effects of E o and (pE).
From Table 6 above it is also apparent that the C D (hE o ) process produces a "synergistic" effect similar to that previously described resulting in lower permanganate number and higher brightness than that which could be predicted from the additive effects of E o and (hE). Moreover, the C D (hE o ) process resulted in pulp having higher viscosity than either the C D E o or C D (hE) variants, an especially remarkable finding since the (hE o ) variant has a much lower permanganate number. That is, the C D (hE o ) process is more selective in removing lignin than either of the individual processes of E o or hE.
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 equivalent of the features shown and described or any portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.
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A multi-stage process for the delignification and bleaching of lignocellulosic pulp is disclosed wherein the first alkaline extraction stage comprises extracting the pulp with caustic in the presence of oxygen and either a hypochlorite or a peroxide.
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TECHNICAL FIELD
This invention relates to congestion management for high speed queuing.
BACKGROUND
Some network devices such as routers and switches have line speeds that can be faster than 10 Gigabits. For maximum efficiency the network devices should be able to process data packets, including storing them to and retrieving them from memory at a rate at least equal to the line rate. Network devices implement congestion avoidance algorithms such as Weighted Random Early Discard (WRED) to preserve chip resources and to regulate packet flow by probabilistically dropping packets as output queue lengths increase beyond predefined limits. The count of packets or buffers for each queue should be observable for all output queues.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a network system.
FIG. 2 is a block diagram of a network device used in the system of FIG. 1 .
FIG. 3 is a block diagram of an output queue.
FIG. 4 is a block diagram of a datapath in a processor.
FIG. 5 is a block diagram of entries in a CAM device to track queue descriptors.
FIG. 5A is a block diagram of an instruction format.
FIG. 6 is a flow diagram of a queue description update process.
DETAILED DESCRIPTION
Referring to FIG. 1 , a network system 10 for processing data packets includes a source of data packets 12 coupled to a network device 14 and a destination for data packets 16 coupled to the network device 14 . The network device 14 includes a processor 18 and a memory 20 having memory data structures 22 configured to receive, store and forward the data packets to a specified destination. Example network devices 14 are network switches, network routers and other network devices. The source of data packets 12 can include, for example, other network devices (not shown) connected over a communications path (not shown) operating at high data packet transfer line speeds. Examples of such communications paths include as an example, an optical carrier (OC)-192 line or a 10-Gigabit Ethernet line. The destination of data packets 16 may also include other network devices as well as a similar network connection.
Referring to FIG. 2 , the network device 14 includes memory 20 coupled to the processor 18 . The memory 20 provides output queues 22 and their corresponding queue descriptors 24 in a queue array 26 . The memory 20 includes a queue manager programming engine 27 and Content Addressable Memory (CAM) 28 .
Upon receiving a data packet from the source 12 (of FIG. 1 ), the processor 16 performs enqueue and dequeue operations to process the packet. An enqueue operation adds information that has arrived in a data packet to one of the output queues 22 and updates its corresponding queue descriptor 24 . A dequeue operation removes information from one of the output queues 22 and updates the corresponding queue descriptor 24 , allowing the network device 14 to transmit the information to the appropriate destination 16 .
Enqueue and dequeue operations for a large number of output queues 22 in memory 20 at high bandwidth line rates can be accomplished by storing some of the queue descriptors 24 in a cache 42 at the processor's memory controller 44 . Commands to perform enqueue or dequeue operations check whether queue descriptors 24 corresponding to the enqueue or dequeue commands are stored in the cache 42 . When an enqueue or a dequeue operation is required with respect to a queue descriptor 24 that is not in the cache 42 (a cache miss), the processor 18 issues commands to the memory controller 44 to move a queue descriptor 24 from the cache 42 to the memory 20 and to fetch a new queue descriptor 24 from memory 20 for storage in the cache 42 . In this manner, modifications to a queue descriptor 24 made by enqueue and dequeue operations occur in the cache 42 and are copied to the corresponding queue descriptor 24 in memory 20 upon removal of that queue descriptor 24 from the cache 42 .
A sixteen entry CAM 28 with a Least Recently Used (LRU) replacement policy is used to track sixteen queue descriptors 24 that are cached in a queue array 46 of the memory controller 44 .
Using a network device 14 implemented as hardware-based 10 multi-threaded processor having multiple microengines 19 , each CAM entry stores a 32 bit value. Microengines 19 each maintain a plurality of program counters in hardware and states associated with the program counters. Effectively, a corresponding plurality of sets of threads can be simultaneously active on each of the microengines 19 while only one is actually operating at any one time. During a lookup operation CAM entries are compared against a source operand. All entries are compared in parallel, and the result of the lookup is a 6-bit value. The 6-bit result includes a 2-bit code concatenated with a 4-bit entry number. Possible results of the lookup are three fold. A first result is a miss where the lookup value is not in the CAM 28 and the entry number is the Least Recently Used (LRU) entry which can be used as a suggested entry to replace. The second result can be a hit where the lookup value is in the CAM 28 and state bit is clear, and the entry number is an entry which has matched. In addition, a locked result may occur where the lookup value is in the CAM 28 , the state bit is set and the 5 entry number is an entry. The state bit is a bit of data associated with the entry, used typically by software. There is no implication of ownership of the entry by any context.
Referring to FIG. 3 , an example of an output queue 22 and its corresponding queue descriptor 24 is shown. The output queue 22 includes a linked list of elements each of which has a pointer 32 to a next element's address 34 in the output queue 22 . Each element in the linked list 30 includes the address 34 of information stored in memory 20 that the linked list element represents. The queue descriptor 24 includes a head pointer 36 , a tail pointer 38 and a count 40 . The head pointer 36 points to the first linked list element 30 of the queue 22 , and the tail pointer 38 points to the last linked list element 30 of the output queue 22 . The count 40 identifies a number (N) of linked list elements 30 in the output queue 22 .
Referring to FIG. 4 , details of an arrangement of the CAM 28 in a datapath 70 of the network device 14 are shown. A General Purpose Register (GPR) file 72 stores data for processing elements 74 . The CAM receives operands as any other processing element 74 would. Operational code (Opcode) bits in an instruction select which processing element 74 is to perform the operation specified by the instruction. In addition, each of the processing elements 74 , including the CAM 28 , can return a result value from the operation specified by the instruction back to the GPR file 72 .
Referring to FIG. 5 , a CAM 28 includes an array 76 of tags having a width the same as the width of the GPR file 72 . Associated with each of the tags in the array are state bits 78 . During a CAM lookup operation, a value presented from the GPR file 72 is compared, in parallel, to each of the tags in the array 76 with a resulting match signal 80 per tag. The values in each tag were previously loaded by a CAM load operation. During the CAM load operation the values from the GPR file 72 specify which of the tags in the array 76 to load and a value to load. Also during the CAM load operation the state information to load is part of the operand.
The result of the CAM lookup is written to a destination GPR file 82 and includes three fields. A hit/miss indication field 84 , an entry number field 86 and a state information field 88 . If a “hit” occurs, the entry number field 86 is matched. In a “miss,” the entry number field 86 is the Least-Recently-Used (LRU) entry.
The following instructions are one example of instructions used to manage and use the CAM 28 :
Load (Entry_Number, Tag_Value, State Value) Lookup (Lookup_Value, Destination) Set_State (Entry_Number, State_Value) Read_Tag (Entry_Number, Destination) Read_State (Entry_Number, Destination)
The LRU Logic 90 maintains a time-ordered list of the CAM 28 entry usage. When an entry is loaded or matches on a lookup, it is marked as MRU (Most Recently Used). A lookup that misses does not modify the LRU list.
If a queue descriptor 24 required for either an enqueue or dequcue is not in queue array 46 , the queue manager programming engine 27 issues a write-back to memory of the LRU entry, followed by a fetch to the same entry, before issuing the enqueue or dequeue command. If the CAM 28 lookup indicates that the needed queue descriptor 24 is already in the queue array 46 , then the enqucue or dequeue command is issued without replacing an entry.
Each enqueue command increments the count 40 of packets or buffers for a particular output queue 22 . A dequeue command decrements the count 40 of packets or buffers when a pointer to the buffer descriptor 24 at the head of the output queue 22 is updated.
The microengine 19 (in the processor 18 containing multiple microengines 19 ) tasked with congestion avoidance reads the queue descriptors 24 from memory 20 to determine the length (count word 40 ) of each output queue 22 . The queue descriptors 24 for highly used output queues 22 can remain in the queue array 46 of the memory controller 44 for an infinitely long time period. A Write_Q_Descriptor_Count Command is issued by the queue manager programming engine 27 after the enqueue or dequeue command, when the entry used “hits” the CAM 28 . As shown in FIG. 5A , the format of the command is:
Write_Q Descriptor_Count (address, entry).
The command uses two parameters, i.e., address and entry, and keeps the countfield 40 for all queue descriptors 24 current in memory 20 for the microengine implementing congestion avoidance. The write of a single word containing the queue count information for entries that hit in the query array 46 in the cache 42 replaces a write-back of two or three words when a new entry needs to be fetched.
Referring to FIG. 6 , a write queue descriptor process 100 includes receiving ( 102 ) an address and a queue subsequent to an enqueue or dequeue command. The process 100 maintains ( 104 ) a count field for all queue descriptors current in memory for the microengine implementing congestion avoidance. The process 100 writes ( 106 ) a single word containing the queue count information for the queue entry that hits the queue array in the cache.
It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.
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Methods and apparatus, including computer program products, for a write queue descriptor count instruction for high speed queuing. A write queue descriptor count command causes a processor to write a single word containing a queue count for each of a plurality of queue entries in a queue array cache.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. 119 of German Patent Application Number 10241718.0 filed Sep. 9, 2002.
FIELD OF THE INVENTION
[0002] The invention relates to an apparatus and a method for configuring data cells received in a telecommunications process in a continuous stream of data cells of fixed length and each comprising a header and a user data part.
BACKGROUND OF THE INVENTION
[0003] The wide-spread popularity of the Internet in both private and commercial applications has resulted in a sudden increase in the requirement for broadband data connections, the majority of which can be produced over an already existing cable so that furnishing the data line does not add to the costs involved. This technique is used by some telecommunications vendors in public networks of high bandwidth. Transmitting the user data part is done, for example, via the POTS line often already existing at the customer end. In this arrangement the user data can be transmitted in parallel to the so-called narrow-band services, e.g. digital or analog voice or fax communications.
[0004] For fast bidirectional data transmission, use is made, for example, of the asymmetrical digital subscriber line (ADSL) technology in which a modulated analog signal is transmitted via the copper pair of the POTS line. A demodulator circuit as may be a component of an ADSL modem of the customer converts the modulated analog signal into a stream of serial synchronized bits. Synchronizing the serial bit stream satisfactorily makes it necessary that the serial bit stream be permanently available. This is why, should no user data be transmitted at the time, empty data packets (so-called empty cells) are transmitted in a predefined format so that a continual data stream exists in the transmitting and receiving direction.
[0005] In achieving broadband public networks, asynchronous transfer mode (ATM) systems as standardized by the International Telecommunication Union (ITU) are finding increasing application for communicating data between subscribers. In this communication technology, the user data to be transmitted in a format in accordance with a network protocol of the local area network (LAN) is resolved into one or more ATM data cells of a fixed byte length, provided with a destination address and transmitted via packet switching exchanges to the destination address. The ATM data cells need to be converted back at the receiver end into user data in a data format in accordance with the network protocol.
[0006] In network terminology, the various protocol steps are usually termed “layers.” Involved in the case of ATM data communications as cited above are the so-called transmission convergence (TC) layer and the ATM adaption layer (AAL).
[0007] The TC layer represents a processing step controlling communication of the user data via the physical connection of the public network. In this processing step, the user data in the form of ATM cells is received as a serial data stream, checked for transmission errors, and empty cells serving to maintain synchronization are removed. When user data is transmitted, this processing step computes a checksum to be added to the ATM cells to be transmitted. If no user data needs to be transmitted, empty cells are transmitted in the direction of communication.
[0008] The AAL in ATM systems is the member linking cell-oriented transmission of the TC layer to the user data to be forwarded to a higher protocol layer. In ATM technology, various modes of communication are supported for the various applications, each of which is assigned a service type and its own data format of the interface of the AAL to a higher protocol layer. Provided for data transmission with the aid of a modem is the so-called AAL5 service type specially introduced for this application as part of the ATM specification.
[0009] The AAL handles substantially two tasks. For one thing, it provides an interface to the local area network (LAN); for another, ATM cells to be exchanged with the TC layer need to be converted into a suitable data format. This function is handled by the segmentation and reassembly (SAR) function.
[0010] Processing the functions of the TC layer and SAR function of the AAL is usually handled by a special apparatus as may be integrated in an ADSL modem, for example. It is in this apparatus that the received ATM data cells are configured and made available in a format compatible with the network protocol used (for example TCP/IP) for feeding into a LAN connecting the hardware of the net subscriber, e.g., a PC.
[0011] In previously known apparatus of the aforementioned kind, the processing functions of the TC layer and the SAR function of the ATM adaptation layer (AAL) are each implemented in two separate processing units. The two processing units may be achieved in the form of one or more processors in which various programs are handled. Since processing the data in two processing units is done with differing processing times or program priorities, a buffer storage, (e.g., a FIFO) needs to be inserted between the two processing units to hold the data until it is able to be processed by the other processing unit in each case. For reading the data in and out of the buffer storage, a separate interface to the two processing units is needed in each case. This makes the configuration of such apparatus complicated and expensive.
SUMMARY OF THE INVENTION
[0012] It is an object of the invention to provide an apparatus of the aforementioned kind which has a simple and inexpensive configuration as compared to existing apparatus. In addition, it is an object of the invention to provide a corresponding particularly simple method.
[0013] In accordance with one aspect of the invention, an apparatus is provided that comprises a processing unit, configured so that it is able to check data cells for the presence of empty cells, discard the data cells consisting of empty cells, then to check the user data parts of the data cells less the empty cells—without needing to buffer same—to determine whether they belong together, and then to assemble the user data parts of the data cells that belong together into a frame.
[0014] The invention provides a novel way for advantageously configuring data cells wherein user data parts of data cells belonging together of a lower protocol layer are assembled into frames in a single processing unit without buffering, resulting in a buffer storage no longer being needed for the ATM cells less the empty cells while likewise doing away with the interface between various processing units. In addition, empty data cells and data cells not intended for this apparatus are discarded. The processing unit can be configured in a simpler way because irrelevant data cells are discarded at an early stage so that the processing unit now needs to handle substantially fewer data cells.
[0015] In another aspect of the invention, a method is provided that comprises checking the data cells for the existence of empty cells, discarding data cells consisting of empty cells, checking—without buffering—the data cells less the empty cells to determine whether they belong together, and assembling the user data parts of the data cells belonging together into a frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Embodiments of the invention are discussed by way of example with reference to the accompanying drawings, in which:
[0017] [0017]FIG. 1 is a schematic block diagram of one embodiment of an apparatus in accordance with the invention;
[0018] [0018]FIG. 2 is an illustration of a configuration of a data cell as configured by an apparatus in accordance with the invention;
[0019] [0019]FIG. 3 is an illustration of a data unit including a frame comprising data cells as assembled by an apparatus in accordance with the invention;
[0020] [0020]FIG. 4 is a flow chart of one embodiment of a method in accordance with the invention; and
[0021] [0021]FIG. 5 is a flow chart of another embodiment of a method in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] [0022]FIG. 1 illustrates a first embodiment of an apparatus 10 in accordance with the invention for configuring data cells received as a continuous stream of data cells in a data transfer mode; the data transfer mode in this case being an asynchronous transfer mode (ATM). The apparatus 10 may be integrated for example in a modem. The apparatus 10 is connected to a local area network (LAN) 12 as well as to a broadband public network 14 and links the LAN 12 to the public network 14 .
[0023] The apparatus 10 comprises a processing unit 11 which may consist of one or more processors and a program storage 16 connected to the processing unit 11 for storing instructions configured so that they represent the steps of the embodiments of the methods in accordance with the invention such as described below.
[0024] The LAN 12 may comprise one or more computers 15 which, in making use of the network protocol, permit swapping data with the apparatus 10 in accordance with the invention.
[0025] The modem comprising the apparatus 10 is connected, for example, by a flex pair of copper conductors of a POTS connection to the public network 14 in accordance with ADSL technology, the data being communicated in the form of a stream of serial bits.
[0026] The processing unit 11 configures data cells received from the public network 14 so that the data cells are converted into frames configured so that they can be processed at a higher protocol layer. These frames can be communicated via a frame memory 18 connected to the apparatus 10 to the computers 15 which in this way are able to receive data stemming, for example, from a web server via the public network 14 .
[0027] In the case as described in the following, the data cells are communicated in the public network 14 in the form of ATM cells in a continuous stream to the apparatus 10 and the frame of the higher protocol layer represents an AAL5 data unit as an interface to the LAN 12 . The apparatus in accordance with the invention and the method in accordance with the invention can easily be modified, however, so that they are just as applicable for other data cell and frame formats specified differently from the present case as described.
[0028] [0028]FIG. 2 illustrates the configuration of an ATM cell having a fixed length of 53 bytes. The first five bytes form the ATM header and are used as control information, i.e., the actual user data is held in the subsequent 48 bytes.
[0029] The data fields identifying the virtual paths (VPI) and virtual channels (VCI) of the ATM header comprise one or two bytes and form together the destination address as dedicated to each receiver which may, for example, comprise a modem. In ATM, it is the destination address which controls communication of the individual ATM cells by means of the so-called virtual paths and virtual channels.
[0030] The payload type identifier (PTI) bit field of the ATM header consists of 3 bits and is used to distinguish ATM cells containing user data from cells containing system data. In addition, the PTI bit field marks by a predefined bit combination the last ATM cell belonging to a frame.
[0031] The header error control (HEC) field contains an 8-bit checksum defined by means of an error correction function from the first 4 bytes of the header. This so-called HEC value serves to identify headers including communication errors. It is also used for data cell synchronization, to permit ATM cell delineation in the continuous stream of serial bits.
[0032] The generic flow control (GFC) bit field comprising 3 bits and the cell loss priority (CLP) control bit are shown for the sake of completeness, but are not important to the understanding of the apparatus and method of the invention.
[0033] [0033]FIG. 3 illustrates the data format of the AAL5 data unit. Several data cells containing exclusively the user data part of the ATM cells are assembled into a frame, called the service data unit (SDU) frame in FIG. 3. This SDU frame is then memorized for later communication to the next-highest protocol step for further processing.
[0034] Likewise illustrated in FIG. 3 in the AAL5 data unit for ATM communication are further items of control information comprising a two-byte long control data field, of the same length as the SDU frame contained in the two-byte long LENGTH data format, and a four-byte long checksum computed from the value of the SDU frame and held in the CRC32 data field. In addition, filler bits are provided whose function is explained below. Since the control data field is not important for understanding the apparatus in accordance with the invention, no further details thereof are included.
[0035] [0035]FIG. 4 illustrates the steps in a program stored in the program storage unit 10 of the processor(s) 11 of the apparatus 10 for receiving a continuous stream of ATM cells from the public network 14 .
[0036] The flow chart of FIG. 4 representing the steps in one embodiment of the method in accordance with the invention as recycled every time at the starting point of the program 30 for each ATM cell received by the apparatus 10 via the public network 14 .
[0037] Before configuration of the ATM cells can commence, the stream of serial bits received needs to be synchronized for ATM cell delineation. For this purpose four bytes each of the stream of serial bits received are used to form a checksum with the aid of the same error correction function used for computing the HEC value of an ATM cell. This checksum is compared to the HEC value communicated in an ATM cell as the fifth byte. When the computed value tallies with the value as communicated by the fifth byte, the position of the ATM cell header and thus cell delineation is identified. ATM cell synchronization is concluded when this agreement has been detected for a predefined number of ATM cells in sequence.
[0038] In accordance with the synchronization procedure just described, the HEC checksum is computed from the four byte long ATM header in step 32 of the program (see FIG. 4). In the subsequent interrogation step 34 , the check as described above is implemented to see whether the HEC value communicated in the header tallies with the value computed by way of the preceding byte. If a set number of errors in sequence is exceeded, the steps described above can be repeated for synchronizing the serial bit stream to the start of the ATM cell.
[0039] Should the HEC value not be correct, i.e. the computed value fail to tally with the HEC value taken over from the bit stream, a statistics function 36 is called which registers the faulty communication and then discontinues further processing of the ATM cell by jumping to the end of program 38 . If the two HEC checksums tally, the program branches to interrogation step 40 .
[0040] As previously mentioned, as in the majority of connecting techniques so too in the ATM method as described presently as an example, the stream of data cells needs to be communicated without interruptions. This is why, should no user data be communicated at the time, empty cells are transmitted in a predefined format. On interrogation 40 , a check is made as to whether the ATM cell just received is an empty cell or a cell including user data or control data of a system cell as detailed below. This is done by way of the HEC checksum of the ATM cell header which assumes a predefined value characteristic of empty cells being present if an empty cell is involved, the program branches to the end 38 , so that empty cells are not included in further processing.
[0041] Should the ATM cell being processed at the time not be an empty cell, the program jumps directly to interrogation step 42 —in which—without prior buffering of the remaining ATM cells less the empty cells the destination address contained in the VCI and VPI data fields of the ATM header of the remaining ATM cells is checked for correctness. Should the received ATM cell not be destined for the receiver, i.e. the apparatus 10 or a modem comprising the apparatus, the destination address fails to tally with a predefined address as memorized, for example, in a configuration register of the apparatus in accordance with the invention. In this case the ATM cell is discarded and processing discontinued at end 38 of the program.
[0042] The remaining steps in the program are thus implemented solely for ATM cells having no empty cells and a valid destination address.
[0043] On interrogation 44 , a check is made by analyzing the PTI bit field of the ATM header to see whether the ATM cell can be classified as a user cell or system cell. System cells—also termed network cells or operations and maintenance (OAM) cells—are used, for example, for testing data communications or to measure the response time of the receiver.
[0044] If the latest ATM cell is an OAM cell, the next step is its further processing in function block 46 . Here, the desired information is made available and the modified OAM cell can be transmitted back e.g. to the sender of the ATM cell. If user cells are being communicated at the time, the processor jumps to interrogation step 48 .
[0045] The data format of the AAL5 data unit provides a maximum length of 64 kbyte for the SDU frame (see FIG. 3). In this frame, which is substantially larger than the user data part of a single ATM cell shown in FIG. 2, the user data parts of several ATM cells are assembled into a larger frame, ignoring the ATM header.
[0046] On interrogation 48 , a check is then made by way of the PTI bit field in the ATM cell header to see whether all ATM cells belonging to a frame have already been communicated, i.e., whether the ATM cell being checked at the time is the last cell belonging to an SDU frame. The PTI bit can exhibit one of two predefined values, one value for the case that the ATM cell is not the last, and the other value for the case that the ATM cell is the last belonging to an SDU frame. Should the PTI bit indicate that the ATM cell is not the last belonging to the SDU frame being formed at the time, in routine 50 the user data part of the ATM cell is copied into the SDU frame memory 18 .
[0047] If the ATM cell being processed at the time is the last belonging to the SDU frame being formed at the time, in function 52 the additional control data of the AAL5 data unit as described above with reference to FIG. 3 and the filler bits are removed. The remaining user data part of the ATM cell is copied into the SDU frame memory 18 .
[0048] This concludes configuring of an ATM cell and the program is terminated by the end of program 38 . If the ATM cell happens to be the last cell in an SDU frame as just formed, this concludes formation of the SDU frame which is then made available in the frame memory 18 for further protocol layers of the communication protocol. Should the ATM cell not be the last cell in an SDU frame as just formed, the program is recommenced at step 30 .
[0049] In the embodiment of the method in accordance with the invention as described above, the ATM cells belonging to an SDU frame were received one after the other and then assembled into the SDU frame. In accordance with an alternative embodiment, the ATM cells belonging to various SDU frames may also be received interleaved. Then, from the VPINCI bit in the ATM cell header, it is evident to which SDU frame they belong in each case. In the frame memory 18 , a separate segment is then firstly allocated for each SDU frame to be commenced new, the various segments being simultaneously filled with the user data parts of the ATM cells arriving interleaved.
[0050] In addition to receiving and configuring the data cells, the apparatus 10 in accordance with the invention may also serve in a further embodiment to generate and transmit data cells as will now be briefly described.
[0051] [0051]FIG. 5 illustrates the steps in a program, in accordance with the invention, needed to transmit ATM cells to the public network 14 as may be likewise stored in the program storage 16 of the processor(s) of the apparatus.
[0052] The sequence in the part of the program for transmitting commences at point 60 in starting the program.
[0053] In the next step, a check is made on interrogration 62 as to whether a system cell as modified above (OAM cell) is to be transmitted. This has priority treatment over frames and is instantly transmitted as a complete ATM cell by means of the routine 64 .
[0054] If no OAM cells exist, in the next step a check is made on interrogation 66 as to whether a frame including user data is to be transmitted. If no user data is available, the program sequence branches to block 68 in which empty cells are generated in an ATM cell format. These empty cells are then likewise transmitted by being inserted into the continually transmitted stream of data cells (jump to point 80 of the program).
[0055] If an SDU frame for communication is made available from the higher protocol layer in the frame memory 18 , a program loop comprising a routine 70 and interrogation 72 is cycled until all user data of the SDU frame have been segmented into single user data fields of 48 bytes each and communicated in the form of ATM cells. The routine 70 generates and transmits the data of an ATM cell by making the header elements of the ATM cell being made available as shown in FIG. 2, the HEC value computed as described above and a 48 byte long user data field copied from the SDU frame into the user data part of the ATM cell.
[0056] On interrogation 72 , a check is made on the basis of the length of the SDU frame and the number of ATM cells already transmitted to see whether segmenting a complete SDU frame into the ATM cells has been concluded. If segmenting has not been concluded, the routine 70 is retrieved, otherwise the program branches to step 74 .
[0057] Since the SDU frames do not necessarily comprise a length corresponding to a whole number multiple of 48 bytes, i.e. the length of the user data (or control data) part of an ATM cell, filler bits are added to the bits for the last ATM cell belonging to a frame during step 74 in the program in addition to the remaining user data comprising the control data, the length field and the CRC32 field so as to achieve the specified length of 48 bytes. This ATM cell is then transmitted in concluding segmenting of the SDU frame to be transmitted.
[0058] The program then branches to end of program 80 which in turn instantly jumps to the start 60 in which a new ATM cell, OAM cell or empty cell is made available for data communication so that a continual stream of data cells is transmitted across the public network 14 to the receiver.
[0059] With the aid of the steps in the program as described above with reference to FIG. 4, configuring the user data part from belonging-together ATM cells into SDU frames can now be done in a single step without needing to buffer data before the SDU frames are formed. More particularly, this eliminates the need to save the ATM cells less the empty cells in a buffer, e.g., a FIFO. This likewise applies to composing ATM cells from segmenting SDU frames as described with reference to FIG. 5 without necessitating a buffer. This now enables the functions, usually implemented in the TC layer and SAR function of the AAL to be implemented in a single processing means.
[0060] The steps in the method in accordance with the invention can be implemented by a processor which serves a program held in the program storage, for example in the form of interrupt routines. By discarding empty cells and incorrectly addressed data cells without prior buffering of the data before generating the frames, the memory capacity requirement as well as the memory access frequency are considerably reduced so that a relative simple processor can now be used in thus permitting cost-effective fabrication of the apparatus in accordance with the invention.
[0061] As evident to those persons skilled in the art, the steps in accordance with the invention may also be implemented by hardware logic as may be a component of the apparatus 10 for configuring the data cells and forming their processing means.
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An apparatus is provided for configuring data cells received in a telecommunications process in a continuous stream of data cells of fixed length and each comprising a header and a user data part. The apparatus comprises a processing unit, adapted and configured so that it is able to check data cells for the presence of empty cells, discard the data cells consisting of empty cells and then check the user data parts of the data cells less the empty cells—without the need to buffer the same—as to whether they belong together, and then to assemble the user data parts of the data cells belonging together into a frame. The apparatus may be integrated in, a modem and is also particularly suitable for data cells existing as ATM cells for receiving by an ATM system. The invention relates in addition to a correspondingly sequencing method for configuring data cells.
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BACKGROUND OF THE INVENTION
Hydrogen peroxide has heretofore been manufactured by the electrolysis of ammonium hydrogensulfate solution, but recently a process for its manufacture using anthraquinone is being widely adopted. The process for manufacturing hydrogen peroxide using anthraquinone is what is called "anthraquinone process", in which as the working solution use is made of a solution obtained by dissolving an alkylanthraquinone in a suitable solvent or a mixture of solvents. In this process hydrogen peroxide is obtained in such a way that first hydrogen gas is blown into the working solution so as to reduce the alkylanthraquinone in the solution to alkylanthrahydroquinone, and then, into the resulting solution is blown an oxygen-containing gas to effect oxidation, whereby the alkylanthrahydroquinone is again oxidized to regenerate the alkylhydroquinone and at the same time hydrogen peroxide is generated. While the hydrogen peroxide thus produced is recovered by extraction with water from the working solution, the working solution is circulated for rense.
As the alkylanthraquinone used in the above described process there may be mentioned 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, etc., but among them 2-amylanthraquinone (hereinafter referred to as "AMQ") is the most useful compound because of its high solubility in the working solution.
Thus, the AMQ now used in the industry is always a mixture of 2-t-amylanthraquinone (hereinafter referred to as "t-AMQ") and 2-s-isoamylanthraquinone(hereinafter referred to as "s-AMQ"), and such a situation indeed stems from the fact that the 2-(amylbenzoyl)benzoic acid itself which is the starting material of preparation of AMQ, is a mixture of 2-(t-amylbenzoyl)benzoic acid (hereinafter sometimes referred to as "AMB acid") and 2-(s-isoamylbenzoyl)benzoic acid (hereinafter referred to as "s-AMB acid"). That is to say, in the process for preparation of AMB acid, wherein t-amylbenzene is reacted with phthalic anhydride in the presence of Lewis acid, it is impossible to obtain a mixture containing more than 55% of t-AMB acid, so that also in the AMQ prepared from such AMB acid the content of t-AMQ cannot be more than 55% as a natural consequence. This is because when t-amylbenzene and phthalic anhydride react in the presence of Lewis acid, portion of the t-amyl radical is converted to s-isoamyl radical by isomerization.
DESCRIPTION OF PRIOR ART
As described in Japanese Public Disclosure of Patent Application No. 75558/1973, in the case where hydrogen peroxide is manufactured by the use of a mixture of t-AMQ and s-AMQ, if s-AMQ is predominant in the mixture ratio, the solubility of amylanthrahydroquinone in the working solution decreases, so that not only does the yield of hydrogen peroxide per a definite quantity of working solution decrease, but also portion of AMQ suffers decomposition to form oxyanthrone, tetrahydroanthrone, anthrone, etc. which render the regeneration of AMQ impossible, at the same time causing a considerable difficulty in the pufication of hydrogen peroxide due to these impurities. Such being the case, in order to prepare AMQ containing a high percentage of t-AMQ a number of investigations have been attempted. For instance, there have been proposed (1) a process wherein t-AMQ is separated from the conventional mixture of t-AMQ and s-AMQ (Japanese Public Disclosure of Patent Application No. 75558/1973), (2) a process wherein t-amylmagnesium parahalide obtained by reacting p-halo-t-amylbenzene with magnesium is condensed with phthalic anhydride to give 2-(4'-t-amylbenzoyl)benzoic acid and then this is converted to t-AMQ by cyclization (Japanese Patent Publication No. 32517/1972 corresponding to French Patent No. 6917283), and (3) a process wherein AMB acid containing a high percentage of t-AMB acid is prepared by the use of both Lewis acid and phthalic anhydride in large excess to t-amylbenzene, and then this is converted to AMQ containing a high percentage of t-AMQ by cyclization (Japanese Public Disclosure of Patent Application No. 75558/1973). But, in the process of (1) the yield of t-AMQ decreases inevitably, and in the processes of (2) and (3) the adoption of Grignard process and the use of Lewis acid and phthalic anhydride in large excess add to the cost, and so on, so that it is the present situation that such deficiencies are hampering the industrial practice in any of these processes.
SUMMARY OF THE INVENTION
In view of such a situation the present inventors have made an elaborate investigation in order to obtain the AMB acid containing a high percentage of t-AMB acid which may be used as the starting material for the preparation of the AMQ containing a high percentage of t-AMQ. As a result it was discovered that when t-amylbenzene reacts with phthalic anhydride in the presence of Lewis acid, the AMB acid containing a high percentage of t-AMB acid can be obtained with extreme ease merely by applying one of the means selected from the group consisting of the means of introducing an inert gas or an inert low boiling liquid gasifiable at the reaction temperature into the reaction system and the means of reducing the pressure of the reaction system, and thus the present invention was achieved.
That is to say, in accordance with this invention the AMB acid containing a high percentage of t-AMB acid can be obtained by applying either the means of introducing an inert gas or an inert low boiling liquid gasifiable at the reaction temperature into the reaction system or the means of reducing the pressure of the reaction system under otherwise the same conditions as the conventional process, and using the AMB acid thus obtained as the starting material, the AMQ containing a high percentage of t-AMQ can be obtained by the conventional process.
The reason why the application of such means enables us to obtain the AMB acid containing a high percentage of t-AMB acid is not yet clear and now under investigation, but it may probably be attributable to the fact that the expulsion of the hydrogen halide formed as by-product during the reaction, resulting from the introduction of an inert gas or reduction of pressure, causes the concentration of said hydrogen halide within the reaction system to decrease, so that the isomerization of from t-amyl radical to s-amyl radical is hampered.
Either of the means of suppressing the isomerization, which are the indispensable requirement in the process of this invention, may achieve almost the same effect.
The process of this invention will be explained more fully below. The first means comprises an introduction of an inert gas or an inert low boiling liquid gasifiable at the reaction temperature into the reaction system while t-amyl benzene and phthalic anhydride are reacting.
As the inert gas use can be made of a variety of prior-known gases, such as, for instance, air, nitrogen, oxygen hydrogen, nitrogen oxide, sulfur dioxide, carbon monoxide, carbon dioxide, freon gas, sulfur hexafluoride, rare gases, e.g., helium, neon, argon, etc., and gaseous saturated hydrocarbons, e.g., methane, ethane, propane, etc. Among them the most preferable are air, oxygen, nitrogen, carbon dioxide, etc. As the inert low boiling liquid gasifiable at the reaction temperature use can be made of low boiling liquids such as, for instance, carbon disulfide, carbon tetrachloride, when the reaction is carried out at a temperature above the gasification temperature of said liquids.
There is no particular limitation to the method of introducing the above described gases or liquids. For instance, they may be either blown into the reaction mixture through a pipe, or blown against the surface of the reaction mixture under agitation, and so on. In such a case, however, it is preferable that the gas is introduced continuously or intermittently throughout the whole period of the reaction or in the initial stage of the reaction. The quantity of the gas introduced is not critical, but usually about 5-1500 cc per ml of reaction liquid will suffice.
The second method comprises reducing the pressure of the reaction system during the reaction. Since the reaction is usually conducted under the ordinary pressure, it will suffice to reduce the pressure of the reaction system somewhat below about 500 mm Hg. Although the extent of reduction of the pressure is not limitative, there is found a tendency that the larger the extent of reduction the more effect of this invention can be exhibited. Thus, it is usually preferable to carry out the reaction below 330 mm Hg. Even under a high vacuum as low as less than 10 mm Hg the process of this invention is of course feasible, but as the reaction solvent becomes more liable to volatilize it is economically undesirable. In this invention, therefore, it is most desirable to carry out the reaction under a pressure reduced to about 50-250 mm Hg. In the practice of this invention, there is no need of reducing the pressure of the reaction system throughout the whole period of the reaction, and by reducing the pressure of the reaction system only in the initial stage of the reaction the AMB acid containing a high percentage of t-AMB acid can be produced. The method of reducing the pressure of the reaction system is not critical, and use can be made of any usual pressure-reducing apparatuses such as a vacuum pump, an aspirator, etc. as they are.
The relative quantities of phthalic anhydride and t-amyl-benzene used in this invention are not particularly limitative, and the relative quantities within the range as used in the conventional process can always produce almost the same effect. Heretofore, it is also reported that by the use of an excess quantity of phthalic anhydride against the quantity of t-amyl-benzene the AMB acid containing a higher percentage of t-AMB acid can be prepared, but it is a quite surprising fact that when the process of this invention employs jointly this condition the percentage of t-AMB acid can be remarkably increased.
As the Lewis acid use can be made of a variety of prior-known compounds, such as aluminum chloride, aluminum bromide, ferric chloride, zinc chloride, boron trifluoride, etc., among which aluminum chloride is most preferable. The Lewis acid need not be used in large excess, so that as in the conventional process about 2 moles or excess (usually 2-2.2 moles) per mole of phthalic anhydride will suffice.
The solvents used in this invention include a variety of solvents usually used in Friedel-Crafts reaction, such as, for instance, chlorobenzene, dichlorobenzene, trichlorobenzene, tetrachloroethane, etc. The reaction temperature employed is usually 0°-100° C, or preferably 15°-60° C, and the reaction time is usually on the order of 2-15 hours.
The AMB acid prepared in the above described way is separated and purified by the prior-known conventional means such as recrystallization, etc.
The AMB acid containing a high percentage of t-AMB acid obtained in accordance with this invention can be readily converted to the AMQ containing a high percentage of t-AMQ.
DETAILED DESCRIPTION OF THE INVENTION
In order to make this invention more understandable Examples and comparative Examples will be shown below.
EXAMPLE 1
One mole of phthalic anhydride, 1.0 mole of t-amylbenzene, and 2.1 moles of aluminum chloride are reacted for 4 hours at 40° C in 6.0 moles of chlorobenzene under a reduced pressure of 250 mm Hg. Then the reaction liquid is discharged into dilute sulfuric acid so as to decompose the reaction product, and the solvent layer is separated and thoroughly washed with hot water. After unreacted phthalic acid has bee removed, the AMB acid formed is extracted from the solvent layer with a dilute aqueous solution of sodium hydroxide. The extract obtained by the aqueous solution of sodium hydroxide is acidified with dilute sulfuric acid to deposit the AMB acid, which is filtered, thoroughly washed with water, and then dried to give a yield of 93 mole % as AMB acid. By the analysis of the AMB acid obtained based on NMR spectrum the ratio of the amyl radical isomers was found to be t-AMB acid : s-AMB acid = 65.3 : 34.7.
Further, when this AMB acid was cyclized with 2% fuming sulfuric acid according to the conventional process, AMQ could be readily obtained. By the analysis of this AMQ based on NMR spectrum the ratio of the isomers was found to be t-AMQ : s-AMQ = 68.5 : 31.5.
COMPARATIVE EXAMPLE 1
When Example 1 was repeated except that the reaction in Example 1 was carried out under the ordinary pressure, AMB acid was obtained in a yield of 90 mole %. Further, by its cyclization AMQ was obtained. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 45.6 : 54.4,
t-AMQ : s-AMQ = 48.5 : 51.5.
EXAMPLE 2
By repeating Example 1 except that the reaction in Example 1 was carried out under a reduced pressure of 250 mm Hg for 2 hours after the initiation of the reaction, and after the pressure of the reaction system has been returned to the ordinary pressure the reaction was further continued for 2 hours, AMB was obtained (yield 90%). Further, by its cyclization AMQ was obtained. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 63.8 : 36.2,
t-AMQ : s-AMQ = 66.5 : 33.5.
EXAMPLE 3
By repeating Example 1 except that the reaction in Example 1 was carried out first by reducing the pressure within the reactor to about 50 mm Hg at the time of charging starting materials and then by maintaining the pressure at about 100 mm Hg., AMB was obtained (yield 95 mole %). By its cyclization AMQ was obtained. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 71.3 : 28.7
t-AMQ : s-AMQ = 74.1 : 25.9
EXAMPLE 4
By repeating Example 1 except that chlorobenzene used in Example 1 was replaced by dichlorobenzene and the reaction was carried out at 50° C, there was obtained AMB acid, from which AMQ was obtained by cyclization. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 71.6 : 28.4
t-AMQ : s-AMQ = 73.6 : 26.4
EXAMPLE 5
While blowing dry air into 6 moles of chlorobenzene liquid 1.0 mole of phthalic anhydride, 1.0 mole of t-amylbenzene, and 2.1 moles of aluminum chloride are added to the liquid. Continuing the blowing of dry air reaction is carried out for 4 hours at 40° C. Then the reaction liquid is poured in dilute sulfuric acid so as to decompose the reaction product, and the solvent layer is separated and, thoroughly washed with hot water. After removal of unreacted phthalic acid the AMB acid formed is extracted from said solvent layer with a dilute aqueous solution of sodium hydroxide. The extract obtained by the aqueous solution of sodium hydroxide is acidified with dilute sulfuric acid to deposit AMB acid, which is filtered, thoroughly washed with water, and then dried (yield 87 mole %). By the analysis of the AMB acid thus obtained based on NMR spectrum the ratio of the amyl radical isomers was found to be t-AMB acid : s-AMB acid = 77.6 : 22.4. Further, with respect to the AMQ which was obtained by cyclizing this AMB acid with fuming sulfuric acid, the analysis based on NMR spectrum showed t-AMQ : s-AMQ = 79.0 : 21.0 in the ratio of the isomers.
EXAMPLE 6
By repeating Example 5 except that dry air was blown against the surface of the reaction liquid instead of blowing dry air into the reaction liquid in Example 5, there was obtained AMB acid (yield 88 mole %), which was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 70.8 : 29.2
t-AMQ : s-AMQ = 73.7 : 26.3
EXAMPLE 7
By repeating Example 5 except that nitrogen was used in place of air and reaction was carried out for 2 hours at 55° C in Example 5, there was obtained AMB acid (yield 91 mole %), which was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 68.2 : 31.8
t-AMQ : s-AMQ = 71.7 : 28.3
EXAMPLE 8
By repeating Example 5 except that helium was used in place of air in Example 5, there was obtained AMB acid (yield 88 mole %). In this example, however, the helium was circulated for reuse. After the hydrogen chloride gas mixed in the gaseous effluent from the reaction system has been removed by the use of sodium hydroxide the gaseous effluent was again blown into the reaction mixture for reuse. The AMB acid was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 74.4 : 25.6
t-AMQ : s-AMQ = 75.9 : 24.1
EXAMPLE 9
By repeating Example 5 except that ordinary air as it was used in place of dry air in Example 5, there was obtained AMB acid (yield 72 mole %). In this example, however, air was allowed to enter the reaction system through an air introducing tube in such a way that placing one end of said air introducing tube outside the reaction system and the other end within the reaction liquid, the pressure of the reaction system is weakly reduced. The AMB acid was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 68.3 : 31.7,
t-AMQ : s-AMQ = 70.5 : 29.5.
EXAMPLE 10
By repeating Example 5 except that using 2.0 moles of aluminum chloride in Example 5 reaction was carried out for 10 hours at 30° C, there was obtained AMB acid (yield 85 mole %), which was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 85.1 : 14.9,
t-AMQ : s-AMQ = 87.3 : 12.7
EXAMPLE 11
By repeating Example 5 except that orthodichlorobenzene was used in place of chlorobenzene in Example 5 and reaction was carried out for 4 hours at 45° C, there was obtained AMB acid (yield 86 mole %), which was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 68.4 : 31.6,
t-AMQ : s-AMQ = 70.9 : 29.1
EXAMPLE 12
By repeating Example 5 except that the time of blowing dry air was limited to 2 hours after the initiation of the reaction, and thereafter, without blowing air, the reaction was further carried out for 2 hours, there was obtained AMB acid (yield 90 mole %), which was cyclized to give AMQ. The ratios of the isomers in the respective products were as follows:
t-AMB acid : s-AMB acid = 71.2 : 28.8,
t-AMQ : s-AMQ = 73.5 : 26.5.
EXAMPLE 13
While blowing dry air at a rate of 100 liters/hour into 12 moles of chlorobenzene liquid 2.0 moles of phthalic anhydride, 1.0 mole of t-amylbenzene, and 3.0 moles of aluminum chloride are added to the liquid. Continuing the blowing of dry air reaction is carried out for 2.0 hours at 40° C, and after stopping the blowing of air, the reaction is further continued for 2.0 hours at 40° C. Then the reaction liquid is poured in dilute sulfuric acid so as to decompose the reaction product. The resulting solution is allowed to stand overnight (several hours), and the crystals of phthalic acid deposited are removed by filtration. The solvent layer is separated from the filtrate and thoroughly washed with hot water to remove the remaining unreacted phthalic acid. Then AMB acid is extracted from the solvent layer with an aqueous solution of sodium hydroxide, and the extract obtained by the aqueous solution of sodium hydroxide is acidified with dilute sulfuric acid so as to deposit the AMB acid. The AMB acid thus deposited is recovered by filtration, thoroughly washed with water, and dried (yield 85 mole %). By the analysis of the AMB acid thus obtained based on NMR spectrum the ratio of the isomers of amyl radical was found to be t-AMB acid : s-AMB acid = 87.1 : 12.9. Further, with respect to the AMQ which was obtained by cyclizing this AMB acid with fuming sulfuric acid, the analysis based on NMR spectrum showed t-AMQ : s-AMQ = 89.0 : 11.0 in the ratio of the isomers.
COMPARATIVE EXAMPLE 2
By repeating Example 13 except that dry air is not blown in Example 13, AMB acid was obtained (yield 86 mole %). t-AMB acid : s-AMB acid = 61.0 : 39.0. The ratio of the isomers in the AMQ which was obtained by cyclizing this AMB acid according to the procedure in Example 13 was as follows:
t-AMQ : s-AMQ = 62.3 : 37.7.
EXAMPLE 14
By repeating Example 13 except that the reaction was carried out using the molar ratio of chlorobenzene: phthalic anhydride : t-amylbenzene : aluminum chloride = 6.0 : 1.0 : 1.0 : 2.0, there was obtained AMB acid (yield 87 mole %). t-AMB acid : s-AMB acid = 74.5 : 25.5; t-AMQ : s-AMQ = 75.8 : 24.2.
EXAMPLE 15
By repeating Example 13 except that the reaction was carried out using the molar ratio of chlorobenzene: phthalic anhydride : t-amylbenzene : aluminum chloride = 6.0 : 2.0 : 1.0 : 2.1, there was obtained AMB acid (yield 82 mole %). t-AMB acid : s-AMB acid = 89.2 : 10.8; t-AMQ : s-AMQ = 91.0 : 9.0.
When the reaction was carried out without air blowing the following result was obtained (yield of AMB acid 83 mole %). t-AMB acid : s-AMB acid = 63.8 : 36.2; t-AMQ : s-AMQ = 65.7 : 34.3.
EXAMPLE 16
By repeating Example 13 except that the reaction was carried out using the molar ratio of chlorobenzene : phthalic anhydride : t-amylbenzene : aluminum chloride = 6.0 : 1.5 : 1.0 : 2.1 and instead of blowing air the pressure of the reaction system was reduced to 100 mm Hg for the same period of time, there was obtained AMB acid (yield 84 mole %). t-AMB acid : s-AMB acid = 85.2 : 14.8; t-AMQ : s-AMQ = 86.6 : 13.4.
When the reaction was carried out under no reduction of pressure the following result was obtained (yield of AMB acid 82 mole %). t-AMB acid : s-AMB acid = 61.5 : 38.5; t-AMQ : s-AMQ = 65.7 : 34.3.
EXAMPLE 17
By repeating Example 13 except that the reaction was carried out at 30° C for 10 hours using the molar ratio of chlorobenzene : phthalic anhydride : t-amylbenzene : aluminum chloride = 6.0 : 2.5 : 1.0 : 2.1, while blowing nitrogen gas, there was obtained AMB acid (yield 51 mole %). t-AMB acid : s-AMB acid = 90.4 : 9.6; t-AMQ : s-AMQ = 92.3 : 7.6.
When the reaction was carried out without nitrogen gas blowing the following result was obtained (yield of AMB acid 49 mole %). t-AMB acid : s-AMB acid = 72.1 : 27.9; t-AMQ : s-AMQ = 73.8 : 26.2.
EXAMPLE 18
By repeating Example 13 except that the reaction was carried out using orthodichlorobenzene in place of chlorobenzene and in the molar ratio of orthodichlorobenzene : phthalic anhydride : t-amylbenzene : aluminum chloride = 20.0 : 5.0 : 1.0 : 6.6, there was obtained AMB acid (yield 84 mole %). t-AMB acid : s-AMB acid = 89.8 : 10.2; t-AMQ : s-AMQ = 91.5 : 8.5.
When the reaction was carried out without air blowing the following result was obtained (yield of AMB acid 86 mole %). t-AMB acid : s-AMB acid = 69.2 : 30.8; t-AMQ : s-AMQ = 70.1 : 29.9.
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This invention relates to an improvement in the process for preparation of 2-(amylbenzoyl)benzoic acid containing a high percentage of 2-(t-amylbenzoyl)benzoic acid. More particularly it relates to a process for preparation of 2-(amylbenozyl)benzoic acid wherein said 2-(amylbenzoyl)benzoic acid is prepared by reacting t-amylbenzene with phthalic anhydride in the presence of Lewis acid, characterized by that 2-(amylbenzoyl)benzoic acid containing a high percentage of 2-(t-amylbenzoyl)benzoic acid is produced by suppressing the undesirable isomerization reaction of the amyl radical by applying one of the means selected from the group consisting of the means of introducing an inert gas into the reaction system and the means of reducing the pressure of the reaction system. 2-(Amylbenzoyl)benzoic acid is a compound useful as the starting material of preparation of 2-amylanthraquinone which is an effective organic catalyst in the manufacture of hydrogen peroxide.
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FIELD OF THE INVENTION
[0001] This invention relates generally to the field of water treatment, and particularly to methods and apparatuses for treatment of raw water to yield potable water, or, water fit for human or animal consumption. Most particularly this invention relates to package plants and processes for raw water purification.
BACKGROUND OF THE INVENTION
[0002] In the past, many water treatment methods and apparatuses have been designed and developed. Some are used for the treatment of waste water, to prevent damage to the environment and others are for the purification of raw water, for the safety and health of humans or animals consuming the water. Raw water in this sense means waters from any source, whether raw water, or ground water under the influence of raw water or other water source that requires disinfection and purification before being safe for human consumption. Health and safety concerns relating to potable or drinking water are of an increasing importance in light of deadly pathogens, such as certain strains of E. Coli. Such pathogens are becoming more prevalent due to intensive agricultural techniques and thus more likely to be found contaminating communal raw water sources.
[0003] Many of the prior art water treatments involve large and expensive plants, which require the use of metered amounts of chemicals, such as flocculants to remove turbidity and chlorine for disinfection, among others. While suitable for large scale urban facilities, such plants are not economic for smaller population groups, such as remote towns or small groups of people. Further such complex prior art plants require sophisticated monitoring systems and skilled employees to manage the operation of the plant, which expertise can be difficult to find in rural or smaller communities.
[0004] What is needed is a simple scalable process and apparatus for the treatment of raw water to render the same fit for human consumption. An attempt was made to design such a plant as shown in my own prior Canadian patent application 2,163,799 filed Nov. 27, 1995. However, the plant I describe therein, while providing reasonable results had some limitations and drawbacks. More particularly, the plant called for the use of a third treatment stage consisting of a deep bed of granulated activated carbon, as a final purification step. This last stage of the process treated the water by adsorption, absorption and biological activity. Unfortunately, such a system results in the activated carbon losing its effectiveness over time, which requires that the activated carbon be replaced periodically. By using larger amounts of activated carbon the effective life of the third stage can be increased, but this simply means it is a bigger job to replace it when required. Since the third stage is a deep bed by design, this is a big, messy, and unpleasant job. As such it is likely to be neglected by unsophisticated or undisciplined operators, resulting in a decline in water quality and safety. Quite simply, the activated carbon will lose its effectiveness over time posing a health risk.
[0005] Thus, what is needed is an operator friendly and low maintenance package plant system, which still incorporates the desired treatment requirements without the need for chemicals. Most preferably to maintain such a system operators will not need to shovel out a deep mucky tank of carbon particles as in the prior art.
SUMMARY OF THE INVENTION
[0006] The present invention comprehends a simple and easy to operate and maintain water purification systems for removing water-born pathogens from raw water, and for reducing the concentration of other raw water constituents of concern such as colour, taste and odour, compounds, organic chemicals, turbidity and metals. The present invention is directed to methods and apparatuses that provide potable water for consumption. In particular the present invention is directed to a self contained scalable package plant that is easy to use and maintain and also is reliable in removing pathogens and contaminants.
[0007] Most preferably the present invention provides easy and simple maintenance features to permit the package plant to be easily maintained. Further the present invention avoids the need for constant supervision of the adding of chemicals and avoids the need for periodic messy and labour intensive maintenance. As such, the present invention is more likely to be maintained by small and rural operators than the prior art devices.
[0008] The present invention comprehends treating raw water which is directed into the package plant through an inlet. Then the water is disinfected, most preferably by means of ozone at dosages in the appropriate range of 1.0 to 5.0 mg/L, after which an up flow roughing filter is used to remove larger particulates. Then a slow sand filter, upon which an organic biomass is grown, is used to finally filter and purify the water at filtration rates in the range of 0.1 to 0.4 m/hr. The present invention comprehends using a chemically active medium as one of the filter layers in the roughing filter to, among other things, remove disinfection byproducts from the water being treated, prior to the same reaching the biomass. The empty bed contact time (EBCT) is in the range of 20 to 40 minutes.
[0009] According to a further aspect of the present invention the chemically active filter is most preferably activated carbon and forms the upper layer of the roughing filter. To service the plant, simplified draining and washing steps are facilitated by the physical structures of the package plant elements. The activated carbon can be cleaned by means of a thorough washing, without needing to be replaced, thus avoiding a messy and awkward maintenance step of the prior art.
[0010] Further the present invention includes hydraulic configurations to facilitate the washing steps as well as other structures to separate and remove the detritus removed during washing.
[0011] Thus, according to a first aspect of the present invention there is provided a package plant for treating raw water to produce potable water, said package plant comprising:
[0012] an inlet for receiving water to be treated;
[0013] an ozonator for disinfecting said water;
[0014] an up-flow roughing filter including at least one coarse filter media for removing coarse solids from said water, and at least one less coarse chemically active filter media for removing less coarse solids from said water and any residual disinfectants from said ozonator; and
[0015] a down-flow slow sand filter, said slow sand filter being sized and shaped to promote a biomass growth for purifying said water,
[0016] wherein said chemically active filter media protects said biomass from residual disinfectants and contributes to the removal of the byproducts of disinfection.
[0017] Further, according to a second aspect there is provided a method of maintaining a package plant for producing potable water from raw water sources, wherein said package plant includes an upflow roughing filter and a slow sand filter located in a common tank, said method comprising the steps of:
[0018] draining said common tank through said roughing filter to remove, by back flow, particles trapped in said roughing filter;
[0019] flowing water at a rate of between 30 and 40 m/hr up through said roughing filter to agitate an upper layer of said roughing filter to remove unwanted material from said upper layer to clean the same; and
[0020] causing said unwanted material to flow into an associated wash trough, thereby removing said unwanted material from said common tank without fouling said slow sand filter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Reference will now be made to preferred embodiments of the present invention, by way of example only, and in which:
[0022] [0022]FIG. 1 is a side view of a package plant according to the present invention; and
[0023] [0023]FIG. 2 is a top view of the package plant of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] [0024]FIG. 1 shows a package plant, indicated generally at 10 according to the present invention. The package plant includes a water inlet 12 , a disinfection section 14 , an upflow roughing filter 16 and a slow sand filter 18 leading to an outflow 20 . Each of these elements is described in more detail below.
[0025] The water inlet 12 can be connected to any raw water source, such as surface water from a stream, lake or other surface water source or from a ground water supply that requires filtration. Raw water sources can vary widely in the degree of treatment required to yield potable water. Qualities such as turbidity, discolouration, and the specific type and degree of contamination can vary widely. The present invention is directed to the overall structure and maintenance techniques for a package water plant. The particular process conditions however, will have to be tailored for each particular water source, and may even need to be varied to accommodate seasonal changes in raw water quality. It will be appreciated by those skilled in the art that the present invention comprehends a range of process conditions which may be used to purify a range of raw water quality. Typically such process conditions will be established by due examination and testing of the raw water qualities.
[0026] The raw water is pumped in and then passes through a venturi 22 . As the water speeds through the venturi 22 a low pressure is created, drawing in ozone from an ozonator 24 . To improve disinfection, the ozone is permitted to diffuse and mix with the raw water in a vertical contact column 26 . From there the water is fed into a splitter box 28 . A pump, not shown, is provided to power the raw water past the venturi 22 and up the contact column 26 .
[0027] Although reference has been made to a venturi injector 22 , an ozone generator 24 , and an ozone contact column 26 , it will be understood that the present invention comprehends all forms of pre-ozonation which can be used to treat raw water. A venturi based system is preferred due to its simplicity of operation however a compressor and oxygen feed type system might also be used.
[0028] The venturi 22 has the beneficial effect of automatically regulating the amount of ozone used. The faster the flow of raw water, the greater the low pressure and the more ozone will be drawn in. Conversely for slower flows, less ozone is needed and also less is drawn in through the venturi 22 .
[0029] The contact column 26 is a known device which may be purchased from a third party supplier such as Fabricated Plastics. The purpose of the contact column is to permit the ozone to be fully mixed with the flow of water to promote good disinfection results. The contact column 26 may include baffles (not shown) and the like to promote turbulent flow and good mixing of the ozone with the water. Typically provision will be made in the contact column 26 to vent excess ozone before the water is released from the contact column. The ozone removed can be safely vented, or re-converted to oxygen.
[0030] Once the free ozone has been removed the next step is to allow the water to flow into a splitter box 28 . The purpose of the splitter box 28 is simply to let the water be divided into two or more streams through parallel sets of package plants. Thus, the ozonator 24 is set to provide enough disinfection having regard to the raw water quality and the flow rate of the raw water. To a certain extent, the venturi 22 design can accommodate a variable flow rate automatically, as noted above.
[0031] It can now be understood that the balance of the package plant will be sized to accommodate certain predetermined flow rates (to achieve desired residence times) to operate efficiently. In the event that the demand for potable water exceeds the plant capacity, then plant capacity may be simply increased by adding extra parallel treatment modules and splitting the flow through the splitter box 28 , through two or more parallel treatment facilities. In this way the through put volume can be increased without changing treatment quality. Thus, it can now be appreciated that the present invention comprehends a scalable package plant which can have its through put capacity increased simply by adding parallel treatment modules.
[0032] The next step is to pass the raw but ozonated water through an up flow roughing filter 16 . Good results have been achieved with an up flow filter having three layers, namely, a first layer 30 which is comprised of larger granular material, a second layer 32 having slightly smaller granular material and a third layer 34 having the finest granular material. It will be noted that the roughing filter 16 and the slow sand filter 18 are both contained within a common tank 36 , as will be explained in more detail below. The common tank may for example extend 70 cm above the top of the roughing filter 16 .
[0033] Reasonable results have been achieved with the thickness of the lower layer being 15 cm, and the middle layer also being 15 cm. A space above the outlet 29 can also be provided, which is preferably about 30 cm in height. The upper layer of the roughing filter can be about 40 cm thick.
[0034] The roughing filter removes particulates from the water without coagulant chemicals. It is preferred to use a course granular material of 8 to 12 mm size in the bottom stage, to separate the granular material from the under drains, followed by a middle layer of between 2.5 and 3.5 mm sized granules, followed by a third or upper layer with even finer granules of about 0.8 to 1.2 mms.
[0035] The bottom and middle layers of the roughing filter are for the physical separation and trapping of water born particulates. Thus, the bottom and middle layers can be made from any suitable material, such as aggregate, providing the pore spaces are of an adequate size. Further, while the present invention is shown having two layers of aggregate, more layers could be used if desired. In such a case the gradation of the pore sizes between the layers would permit a removal of even finer particulates prior to the raw water reaching the upper layer.
[0036] The upper layer is most preferably formed from an activated carbon layer. Activated carbon is desirable for several reasons. Firstly, it will remove suspended solids through physical straining, it will fluidize more readily during washing due to its lower specific gravity, it will support biological growth due to its porous structure, and thereby contribute to the removal of byproducts of ozonation, and it will chemically react with ozone or chlorine residuals removing them so that the downstream biological processes are not impaired. As can now be understood, the activated carbon filter layer is positioned upstream of the slow sand filter. The slow sand filter is effective in large measure due to the growth of a biomass on the filter grains. Disinfection components can damage or even destroy such a biomass, leading to a loss of purification function. The present invention therefore provides in a single package plant both a disinfection step and a biomass purification step in which the biomass is protected from the upstream disinfection effects.
[0037] As can be seen the roughing filter is contained in a inner vessel 40 contained within the common tank 36 . Adjacent to the top of the inner vessel 40 is a wash trough 42 , surmounted by a baffle plate 44 . A filter weir is formed at 43 . At the opposite side of the common tank 36 is provided a second wash trough 50 . The wash troughs 42 , 50 are used in the simplified maintenance procedures of the present invention which are explained in more detail below.
[0038] After passing through the activated carbon filter layer the water enters common tank 36 . The common tank may provide for a top liquid level of up to 60 cm above the level of the roughing filter. Once in the common tank 36 the speed of the water is slowed considerably, due to the increase in the cross sectional area of flow from the up flow roughing filter as compared to the down flow sand filter. This permits the water to interact with the biomass of the slow sand filter in a known manner to permit the purification of the water. Drains 60 are provided below the slow sand filter where the treated potable water is removed.
[0039] Good results have been obtained through using a four media slow sand filter. Media 1 is preferably 0.25 to 0.5 mm and extends down about 60 cm. Media 2 and 3 may be made from 0.8 to 1.2 and 2.5 to 3.5 mm respectively sized gravel and may together extend for 10 cm each for a total of about 20 cm. Lastly, Media 4 may be made from 8.0 to 12 mm gravel and extend 20 cm. The drain 60 may be for example in the form of a perforated under drain.
[0040] Although four types of media are shown and provide good results, more or fewer could also be used. Also, while particular sizes of media are taught herein, these too can be varied, without departing from the scope of this invention. The slow sand filter works through a combination of physical straining and biological treatment to remove turbidity, bacteria, viruses, Giardia cysts, and Cryptosporidium oocysts.
[0041] It will be noted that from the top of the ozone contact column to the potable water output is a gravity feed flow path. Thus, the present invention is fairly efficient in terms of its energy demands.
[0042] Having described the position and function of the elements, the improved maintenance procedures of the present invention can now be comprehended. As shown in the FIG. 1, the inner vessel 40 includes an upwardly extending lip at 41 to form weir 43 . The lip extends a distance D above the level of the activated carbon layer. D is a predetermined distance as explained below. Good results have been obtained where D is 30 cm.
[0043] After a certain operation time, the plant of the present invention will need to be taken off line, for maintenance. The exact amount of time permitted between maintenance events will vary, depending upon the properties of the raw water being treated and process conditions. However, over time the pore spaces in the roughing filter will become clogged up and the activated carbon filter may become fouled and lose its effectiveness. Also the slow sand filter biomass may become too overgrown and need to be reduced. This will be indicated by an increase in the head of water in the common tank above the slow sand filter. The present invention thus comprehends periodic maintenance of the plant performed by simply washing the components of the package plant.
[0044] During such periodic plant maintenance, the following procedure is followed. Firstly, the water being pumped into the plant is stopped, so that the flow through the plant stops. Then the water in the common tank needs to be drained. In a first drainage step, the water is drained down through the roughing filter. It is preferred to do this rapidly, over a 5 to 10 minute period, to facilitate flushing the roughing filter. As will now be understood this drainage step will cause the flow through the filter to be in a reverse direction to its normal flow direction. This will have the effect of removing most of the particles which may be stuck in the pore spaces of the lower and middle filter layers and held in place by the flow of water. What has been discovered is that such a reverse flush is not sufficient to clean the activated carbon layer. This is due to two factors. Firstly the flow volume is not enough to dislodge the particles from the smaller pore spaces and secondly, there are likely various forms of growth occurring in the filter which are securely attached to the filter particles. Thus, a different technique is required.
[0045] The present invention provides for pumps to be connected to the lower drain of the roughing filter. Thus, a strong flow of water with a velocity of approximately 35 m/hr can be forced upwardly through the roughing filter for a period of 5 to 10 minutes. One of the advantages of activated carbon is that it has a low specific gravity in the range of 1.2 to 1.6 (saturated). This facilitates agitative washing during the strong washing flow. Thus, the present invention comprehends making the height of D equal to the height the activated carbon layer will reach during the agitative washing step. In this way the individual grains are tumbled and the trapped particles are released. As well, such aggressive washing has been found useful to dislodge growths from the filter grains.
[0046] During the washing step the washed out detritus or other material will tend to be pushed to the top of the inner vessel. Then, it is expelled over the weir 43 into the washing trough 42 . Thus, it can now be appreciated that the baffle 44 prevents such unwanted material from falling into the common tank 36 onto the slow sand filter 18 and instead directs it into the wash trough 42 . The wash trough 42 in turn is drained outside of the plant where the removed material can be safely disposed of. As a result of the agitative washing step the activated carbon filter is cleaned, and no worker or operator was required to enter the tank to remove or replace the same. If some filter material is lost, it may be necessary to top up the same, but if the weir 43 is appropriately positioned this is not too likely to be necessary.
[0047] The next step is simply to wash down the slow sand filter. Once the water head in the common tank is drained to the level of the roughing filter, the top level or surface of the slow sand filter can be washed. Thus, it is preferred to position the wash trough weir at about the same level as the top of the slow sand filter. It has been found that adequate results have been obtained by using a hose to spray the upper surface of the sand, which causes the biomass over growth to separate from and be washed along the surface towards the other wash trough 50 . In this manner the sand filter can also be refreshed to permit higher flow rates to be achieved. If desired, manual scrapers can be used to facilitate the process.
[0048] [0048]FIG. 2 shows the same elements as FIG. 1, from a top perspective. Thus, in FIG. 2 the raw water inlet 12 , the ozonator 24 and the contact column 26 are shown. The splitter box 28 is shown, with a weir 80 , and a baffle 82 . As can now be appreciated, simply by placing one or more baffles 82 at appropriate positions, the flow of water can be diverted into two or more parallel paths. Thus, the splitter box is only required where multiple parallel paths are used.
[0049] Following the splitter box, the water is directed up through the roughing filter 16 and down through the slow sand filter 18 . Wash water waste discharges 84 and 86 are also shown.
[0050] It will be appreciated by those skilled in the art that while reference has been made to a preferred embodiment of the present invention above, various modifications and alterations can be made without departing from the broad spirit of the appended claims. For example, the specific media sizes and depths can be varied somewhat, without altering performance too much, and will be described in some cases depending upon the nature of the raw water source. As well, various disinfection methods could be used, provided that the slow sand biomass is protected from disinfection residuals chemically active media.
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A package plant for treating raw water to yield potable water. The package plant includes an inlet for raw water, followed by an ozonator for disinfecting the water. Next is provided an up flow roughing filter including a chemically active layer, on top. A slow sand filter follows, which is sized and shaped to promote growth of a biomass for water purification. The up flow roughing filter removes particulates, contributes to the removal of dissolved organics, and protects the slow sand biomass by removing disinfection residuals. In another aspect a method of maintaining the plant is provided, including washing the up flow roughing filter by draining water down through it, providing a vigorous up flow to agitate the top layer, and then washing the slow sand filter.
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SCOPE OF THE INVENTION
[0001] The invention relates to the production of interferon alpha 5 for use in compositions useful in the treatment of liver diseases of viral origin.
[0002] We have shown that IFN-alpha 5 is the sole subtype of alpha interferon produced in the healthy liver and that its levels are clearly reduced in chronic hepatitis C, which suggests that this substance may be of therapeutic value in the treatment of this disease and other forms of viral hepatitis. Knowing the coding gene sequence for this interferon, its production through recombinant DNA technology in different hosts makes it possible to develop effective drugs for the treatment of liver diseases of this type at their different stages of development.
STATE OF THE ART
[0003] Infected cells can recognize the presence of a virus by sending out signals which result in the transcription and secretion of type I interferon (IFNα and IFNβ). IFNα is a family of thirteen polypeptides (subtypes) coded by different genes. IFNβ is a glycoprotein produced by a single gene. Different cell types produce both IFNα and IFNβ (1, 2).
[0004] Viral infection is the main stimulus for the production of type I interferon, although there are other factors which can increase its synthesis, such as bacterial components, double chain RNA, growth factors and other cytokines (1). In addition to having its antiviral effect, IFNα can interact with certain cytokines and with T cells regulating the growth and differentiation of the cells in the immune system (3). IFNα genes are expressed as a matter of course in human tissue in healthy individuals (4), while the expression of particular subtypes is restricted to certain cell types (5, 6). The induction of IFN by viruses is mainly regulated at transcription level. The specific activation of transcription occurs through the interaction of cell factors induced by viruses with the domains regulating the promoters of IFNα genes (7).
[0005] All IFNα and IFNβ subtypes have a common receptor at the cell surface. Competitive binding tests at the receptor for different IFNα subtypes indicate that all of these combine at the same receptor, but with different affinities (8). The biological activity of the different subtypes of IFNα is little known. The IFNα 5 and IFNβ 8 interferon subtypes appear to be those having the greatest antiviral activity. Antiproliferative response also differs between the different subtypes (9). In humans unstimulated peripheral blood mononuclear cells express different IFNα subtypes (10).
[0006] A common mechanism for the persistence of viral infection is avoidance of the IFN system. Many viruses have developed strategies to avoid the antiviral effects of IFN. Specifically, a selective defect in the production of IFNα has been described in monocytes infected by human immunodeficiency virus (11).
[0007] Hepatitis C virus (HCV) is a single chain RNA virus which results in chronic infection in more than two thirds of persons infected. The prevalence of infection by HCV is around 2 to 3% in the population of the West. Studies perfonned in Europe show that 33% of patients with chronic HCV infection develop cirrhosis in a mean period of less than 20 years (12). A significant proportion of these patients develop liver cancer, with an annual incidence of 1.4% (13). It has been difficult to find the reason for the high level of persistence of HCV infection. The high rate of mutations in the virus and the production of a predominant profile of Th2 cytokines in comparison with Th1 have been described as being responsible for this high level of persistence by the infection. Treatment with IFN induces a sustained response in around 30% of patients with chronic hepatitis C. The mechanism responsible for response or non-response to treatment with IFN is little understood.
[0008] The IFN system has only been studied in chronic HCV infection. There is no appropriate animal model for chronic HCV infection, and, because of this, investigations performed on humans are the only source of information on the pathophysiology and pathogenesis of chronic hepatitis C. This invention describes the expression of IFNα and IFNβ genes in the liver and in the peripheral blood mononuclear cells (PBMC) in healthy controls and patients with chronic hepatitis C. In addition to this we have analysed the IFNα subtype expressed in normal liver tissue and the liver tissue of patients with chronic hepatitis C. Expression of the different IFNα subtypes has also been analysed in PBMC in healthy controls and patients with chronic hepatitis C.
REFERENCES
[0000]
1. Maeyer E, Maeyer-Guignard J. lnterferons. In Thomson A, ed. The Cytokine Handbook. London: Academic Press Limited 1991: 215-239.
2. Samuel C E. Antiviral Actions of Interferon. Interferon-Regulated Cellular Proteins and Their Surprisingly Selective Antiviral Activities. Virology 1991; 183: 1-11.
3. Tilg H. New Insights Into the Mechanisms of Interferon Alfa: An Immunoregulatory and Anti-inflammatory Cytokine. Gastroenterology 1997; 112: 1017-1021.
4. Tovey M G, Streuli M, Gresser I, Gugenheim I, Blanchard B, Guymarho J, Vignaux F and Gigou M. Interferon messenger RNA is produced constitutively in the organs of normal individuals. Proc. Natl. Acad. Sci. USA 1987; 84: 5038-5042.
5. Bisat F, Raj N B, Pitha P M. Differential and cell type specific expression of murine alpha interferon genes is regulated on the transcriptional level. Nucleic Acids Res 1988; 16:6067-6083.
6. Hiscott J, Cantell K, Weissmann C. Differential expression of human interferon genes. Nucleic Acids Res 1984; 12:3727-3746.
7. Au W C, Su Y, Raj N B K and Pitha P M. Virus-mediated Induction of Interferon A Gene Requires Cooperation between Multiple Binding Factors in the Interferon α Promoter Region. The Journal of Biological Chemistry 1993, 268: 24032-24040.
8. Aguet M, Grobke M, Dreiding P. Various human interferon alpha subclasses cross-react with common receptors: their binding affinities correlate with their specific biological activities. Virology 1984;132:211-216.
9. Foster G R, Rodrigues O, Ghouze F, Schulte-Frohlinde D, Testa D, Liao M J, Stark G R, Leadbeater L, Thomas H C. Different relative activities of human cell derived interferon-alpha subtypes: interferon alpha 8 has very high antiviral potency. J Interferon and Cytokine Res. 1996; 16:1027-1033.
10. Brandt E R, Linnane A W, Devenish R J. Expression of IFN A genes in subpopulations of peripheral blood cells. Br J Haematol 1994; 86:717-725.
11. Gendelman H E, Friedman R M, Joe S, Baca L M, Turpin J A, Dveksker G, Meltzer M S and Dieffenbach C. A Selective Defect of Interferon a Production in Human Immuno-deficiency Virus-infected Monocytes. The Journal of Experimental Medicine 1990; 172: 1433-1442.
12. Poynard T, Bedossa P, Opolon P. Natural history of liver fibrosis progression in patients with chronic hepatitis C. The OBSVIRC, METAVIR, CLINIVIR, and DOSVIRC groups. Lancet 1997; 349:825-832.
13. Fattovich G, Giustina G, Degos F et al. Morbidity and Mortality in Compensated Cirrhosis Type C: A Retrospective Follow-Up Study of 384 Patients. Gastroenterology 1997;112: 463-472.
14. Gil B, Qian Ch, Riezu-Boj J I, Civeira M P, Prieto J. Hepatic and extrahepatic HCV RNA strands in chronic hepatitis C: different patterns of response to interferon treatment. Hepatology 1993;18:1050-1054.
15. Lopez S, Reeves R, Island M L, Bandu M T, Christeff N, Doly J and Navarro S. Silencer Activity in the Interferon-A Gene Promoters. The Journal of Biological Chemistry 1997; 272: 22788-22799.
16. Knodell R, Ishak K, Black W, Chen T, Craig R, Kaplowitz N, Kiernan T, et al. Formulation and application of a numerical scoring system for assessing histological activity in asymptomatic chronic active hepatitis. Hepatology 1981; 1:431-435.
17. Chomczynsky P; Sacchi N. Single-step of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal. Biochem. 1987; 162:156-159.
18. Weissmann C, Weber H. The interferon genes. Prog Nucleic Acid Res Mol Biol 1986; 33:251-300.
19. Goeddel D V, Leung D W, Dull T J, Gross M, Lawn R M., McCandliss R, Seeburg P H, Ullrich A, Yelverton E, Gray P W. The structure of eight distinct cloned human leukocyte interferon cDNAs. Nature 1981; 290:20-26.
20. Derynck R, Content J, DeClercq E, Volckaert G, Tavernier J, Devos R, Fiers W. Isolation and structure of a human fibroblast interferon gene. Nature 1980; 285:542-547.
21. Ng S Y, Gunning P, Eddy R, Ponte P, Leavitt J, Shows T, Kedes L. Evolution of the functional human b-actin gene and its multi-pseudogene family: conservation of noncoding regions and chromosomal dispersion of pseudogenes. Mol Cell Biol 1985; 5:2720-2732.
22. Larrea E, Garcia N, Qian Ch, et al. Tumor Necrosis Factor α Gene Expression And The Response To Interferon In Chronic Hepatitis C. Hepatology 1996; 23: 210-217.
23. Viazov S, Zibert A, Ramakrishnan K; Widell A; Cavicchini A, Schreier E; Roggendord M. Typing of hepatitis C virus isolates by DNA enzyme immunoassay. J. Virol. Methods 1994;48:81-92.
24. Sarobe P, Jauregui J I, Lasarte J J, García N, Civeira MP, Borrás-Cuesta F and Prieto J. Production of interleukin-2 in response to synthetic peptides from hepatitis C virus E1 protein in patients with chronic hepatitis C: relationship with the response to interferon treatment. J Hepatol 1996;25:1-9.
DESCRIPTION OF THE INVENTION
[0000] Patients and Controls
[0000]
The expression of IFNα and IFNβ genes was analysed in samples from liver biopsies from 16 patients with chronic hepatitis C (9 men and 7 women, age range 24 to 71 years). Five of these patients showed cirrhosis. The viral genotype was determined in 14 patients and was lb in 10 patients, la in 2 patients and genotype 3 in 1 patient. In addition to this, expression of the IFNα and IFNβ genes was determined in 12 samples of normal liver obtained by laparotomy from 12 control patients (9 men and 3 women, age range 49 to 70 years). The laparotomies were performed on account of the presence of digestive tumours in 10 patients (4 colo-rectal, 5 gastric and 1 pancreatic) due to chronic pancreatitis in 1 patient and the presence of a hydatid cyst in another patient. Liver histology was normal in the twelve cases. None of these control cases had received treatment before the liver sample was obtained.
[0034] RNAm levels of IFNα and IFNβ were also determined in PBMC in 25 patients with chronic hepatitis C (14 men and 11 women, age range 24 to 69 years) (four of these patients had cirrhosis) and in PBMC from 23 healthy controls (10 men and 13 women, age range from 25 to 66 years). The viral genotype for these patients was lb in 22 patients, la in two patients and 3 in 1 patient.
[0035] The diagnosis of chronic hepatitis C was based on an increase in serum transaminases lasting more than 6 months, a positive result for anti-HCV antibodies (2nd generation ELISA, Ortho Diagnostic System, Raritan, N.J., USA), the presence of C virus RNA in serum (reverse-reaction transcription in the polymerase chain), and histological evidence of chronic hepatitis. The severity of liver damage was evaluated using the Knodell index (16). Other causes of chronic hepatitis other than hepatitis C virus were ruled out. None of the patients had received treatment with IFNα during at least 6 months prior to the study.
[0000] Preparation of Liver, PBMC and Serum Samples
[0036] The liver samples were obtained by liver biopsy using a Tru-Cut biopsy needle (Baxter, Deerfield, Ill.). One third of the sample was immediately frozen in liquid nitrogen and kept at −80° C. until total RNA extraction took place. The remainder of the sample was used for the histological investigation.
[0037] PBMC were isolated from heparinized blood using a density gradient with Lymphoprep (Nycomed Pharma As, Oslo, Norway), centrifuged at 600 g for 30 minutes. After centrifuging the PBMC were collected, washed 5 times with 0.9% NaCl and lysed using Ultraspec™ protein denaturing solution (Biotech Laboratories, Houston, USA). The cellular lysate was kept at −80° C. until total RNA extraction was performed using the method of Chomcznski and Sacchi (17).
[0038] The serum samples were obtained by centrifuging from venous blood collected in sterile tubes. The serum was kept at −40° C. until use.
[0000] Analysis of the Expression of IFNα and IFNβ Genes in the Liver and PBMC
[0039] RNAm levels of IFNα and IFNβ were determined using a quantitative polymerase chain reaction reverse transcription (RT-PCR) method using a thermocycler (Perkin-Elmer Gene Amp PCR system 2400). Prior to reverse transcription 2 μg of total RNA (from both the liver and PBMC) were treated with 1 unit of deoxyribonuclease (DNAse I amplification grade, Gibco-BRL, Gaithersburg, Md., USA) to eliminate possible contaminating DNA. The presence of traces of DNA was checked by including control reactions without reverse transcription. This step is required because of the absence of introns in IFNα and IFNβ genes (18), which made it impossible for us to distinguish the product of PCR from the RNA or possible contaminating DNA. All the controls performed without reverse transcription were negative, indicating the absence of contaminating DNA. Total RNA was transcribed (60 minutes at 37° C.) with 400 units of M-MuLV reverse transcriptase (Gibco-BRL, Gaithersburg, Md., USA) in a final volume of 40 μl of 5× saline solution (250 mM Tris-HCl pH 8.3, 375 mM KCl, 15 mM MgCl 2 ), supplemented with 5 mM DTT, 0.5 mM triphosphate dioxyribonucleotides (Boehringer Mannheim, Mannheim, Germany), 48 units of RNAsas inhibitor (Promega Corporation, MD, US) and 400 ng of random hexamers (Boehringer Mannheim, Mannheim, Germany). After denaturing the reverse transcriptase (95° C., 1 minute) and rapidly cooling over ice, a 10 μl aliquot (0.5 μg) of the cDNA was used to amplify the IFNα and IFNβ by PCR in 50 μl of 10× PCR buffer (160 mM (NH 4 )SO 4 , 670 mM Tris-HCl pH 8.8, 0.1% Tween 20) supplemented with the direction and antidirection primers (40 ng of each one for IFNα and 60 ng for IFNα), 1.2 mM MgCl 2 and 2 units of Biotaq™ DNA polymerase (Bioline, London, LTK). Control reactions without RNA were performed in all the experiments. As an internal control for each sample a fragment of β-actin cDNA was amplified using a 10 μl aliquot of the cDNA obtained previously. The IFNα was amplified by performing 30 or 33 cycles (PBMC or liver respectively) (94° C., 60° C. and 72° C. during 20, 15 and 30 seconds for each step respectively), the INFβ was amplified by performing 30 or 35 cycles (PBMC or liver respectively) (94° C., 58° C. and 72° C. for 20, 15 and 30 seconds for each step respectively) and β-actin was amplified by reacting 18 or 25 cycles (PBMC or liver respectively) (94° C., 55° C. and 72° C. for 20, 15 and 30 seconds for each step respectively), protocols which avoid interference with the PCR reaction saturation stage. The oligonucleotides (5′-3′) d(TCCATGAGATGATCCAGCAG) and d(ATTTCTGCTCTGACAACCTCCC) were used as direction and antidirection primers respectively to amplify a fragment of 274 pairs of bases located between nucleotides 240-514 in the human IFNα gene (19). These oligonucleotides are direction primers designed to amplify all the subtypes of IFNα. The oligonucleotides d(TCTAGCACTGGCTGGAATGAG) and d(GTTTCGGAGGTAACCTGTAAG) were the primers used to amplify a fragment of 276 base pairs located between nucleotides 349-625 of cDNA of human IFNβ (20). d(TCTACAATGAGCTGCGTGTG) and d(GGTGAGGATCTTCATGAGGT) were the primers used to amplify a fragment of 314 base pairs (nucleotides 1319-2079) of the β-actin gene (21).
[0040] After the amplification reactions 20 μl of the PCR product were run in a 2% agarose gel containing ethidium bromide. The bands obtained were displayed using an ultraviolet lamp and were analysed using a commercial programme (Molecular Analyst/PC, Bio-Rad) capable of digitizing and analysing the image obtained. Finally the values corresponding to the expression of the IFNα and IFNβ genes were standardized with their β-actin correlates. The results are expressed as the quotient between the value of IFNα and IFNβ and the β-actin correlate. Previously we demonstrated that the RNAm of β-actin was expressed constantly both in the liver and in the PBMC of patients with chronic hepatitis C (22), which has enabled us to standardize IFNα and IFNβ values with those obtained for β-actin.
[0041] Validation curves for the PCR technique were prepared using known quantities of total RNA (from 0 up to 1 μg). As will be seen in FIG. 3 , with the total initial RNA quantities used for IFNα, IFNβ and β-actin (0.5 μg, for both the liver and PBMC), we were within the linear range of the PCR amplification curve. The inter-test coefficient of variance for IFNα/β-actin was 22% and for IFNβ/β-actin it was 24%. The identity of the PCR product obtained was checked for IFNα and IFNβ by automatic sequencing (ABI prism™ 310 genetic analyser, Perkin Elmer).
[0000] Identification of IFNα Subtypes
[0042] Total RNA extraction, reverse transcription and the PCR reaction were performed as described above, using the IFNα direction primers mentioned. The PCR product obtained was cloned using the commercial TOPO TA cloning kit (Invitrogen, Leek, Holland). At least 6 clones from each insert were sequenced in an automatic ABI PRISM 310 sequencer (Perkin Elmer, Foster, Calif.), using the Dye Rhodamine Terminator Cycle Sequencing Kit (Perkin Elmer, Foster, Calif.).
[0000] Detection, Quantification and Genotyping of C Virus RNA
[0043] The presence of C virus RNA in serum was determined using the RT-PCR technique (14, 22), using 2 pairs of specific primers for the non-coding 5′ region of the C virus genome. The C virus RNA was quantified using the competitive PCR technique previously described by ourselves (22). The viral genotype was determined using Viazov's method (23) as already described previously (22, 24). The test 5′G(A,G)CCGTCTTGGGGCC(A,C)AAATGAT was used to determine genotype 4.
[0000] Statistical Analysis
[0044] The IFNα and IFNβ results are presented as mean ± standard error. The normality of the variables was studied using the Shapiro-Wilks test. Statistical analysis of IFNα and IFNβ values in PBMC or liver was performed using non-parametric tests (Mann-Whitney U test) or parametric tests (Student's T). The association between quantitative variables was investigated using the Pearson or Spearman correlation coefficient, as appropriate. Windows SPSS 6.0 program was used for the statistical analysis.
[0000] Production of Recombinant Protein
[0000] Expression and Purification of Human Interferon-α5 in Escherichia coli:
[0045] Despite the fact that the expression of cDNAs originating from eucaryote organisms in Escherichia coli in general ensures a high level of production, isolation and purification of the protein of interest involves complex procedures and low yields. For this reason expression vectors are used to help obtain merged proteins whose purification is reduced to an affinity chromatography step, with high yield and efficiency.
[0000] Construction of the Expression Vector and Acquisition of Recombinant Bacteria
[0046] The cDNA which codes for interferon-α5 is cloned in pET14b vector (available commercially from Novagen). This vector provides a sequence which codes for a series of histidine residues (1 kDa) which are translated in phase with the cloned cDNA to yield a merged protein which includes a 1 kDa histidine tail at its terminal amine end and then interferon-α5, with a site between the two which can be cut by thrombin.
[0047] Once the expression vector has been obtained, competent bacteria of the BL21 (DE3) strain are prepared, as this strain contains a gene which can be induced by T7 RNA polymerase, which is a necessary requirement for the subsequent production of protein. The competent bacteria are converted with the vector previously obtained (pET14b with the cloned interferon-α5 cDNA). The transformed bacteria are selected by their growth in LB medium with ampicillin, as the vector contains a gene which is resistant to this antibiotic.
[0000] Expression and Purification of Interferon-α5:
[0048] The transformed bacteria are grown in LB medium with ampicillin at 37° C. until an optical density of 0.4 at 600 nm is obtained. Then expression of the recombinant protein with IPTG is induced at a final concentration of 0.5 mM. In this way the lac promoter is induced and as a consequence the T7 RNA polymerase prometer which contains the vector and which regulates the expression of the cloned cDNA is induced. The culture is grown for a further 4 hours under the same conditions.
[0049] To obtain the extracts, once the bacteria have grown, centrifuging is carried out at 4° C. The precipitated bacteria are resuspended in 10 mM Tris/HCl buffer, 10% saccharose, 2 mM 2-mercaptoethanol and protease inhibitors. Homogenization was performed ultrasonically by incubation for 30 minutes with lysozyme at 4° C. This breaks down the bacterial wall and improves the yield of the extraction process. The cytosol extract is obtained by centrifuging the homogenate at 100,000 g for 90 minutes. Protein production is checked by analysing the cytosol fraction by SDS-PAGE.
[0050] His-interferon-α5 merged protein is purified by chromatography of the cytosol extract in a 2 ml nickel column. The protein is eluted by washing the column with 1 M imidazole. The pure protein is processed with thrombin and the interferon-α5 is subsequently repurified by molecular exclusion chromatography.
[0000] Expression and Purification of Human Interferon-α5 in Solanum tuberosum:
[0051] Construction of the expression vector and acquisition of transgenic plants.
[0052] The cDNA which codes for interferon-α5 is cloned in an Agrobacterium tumefaciens expression vector. This vector contains the potato promoter (the most abundant protein in the Solanum tuberosum tubercle), as well as a sequence which codes for a series of histidine residues (1 kDa) and which are translated in phase with the cloned cDNA to yield a merged protein which contains a 1 kDa histidine tail at its terminal amine end followed by interferon-α5, with a site between the two which can be cut by thrombin.
[0053] Once the expression vector has heen obtained, competent bacteria of the GV2260 strain of Agrobacterium tumefaciens are prepared. The competent bacteria are transformad using the previously obtained vector. The transformed bacteria are selected by growth in LB medium with kanamycin, as the vector contains a gene which is resistant to that antibiotic.
[0054] Subsequently a coculture of the transformed bacteria with the plant material ( Solanum tubersosum leaves cultivated in vitro) is performed and the plant cells resistant to kanamycin are selected. These cells are regenerated until transgenic plants are obtained.
[0000] Acquisition and Purification of Interferon-α5:
[0055] Total protein extraction is performed from tubercles of the transgenic plants which express the interferon-α5.
[0056] The purification of His-interferon-α5 merged protein is carried out by chromatography of the protein extract obtained on a 2 ml nickel column. The protein is eluted by washing the column with 1 M imidazole. The pure protein is processed with thrombin and the interferon-α5 is subsequently repurified using molecular exclusion chromatography.
[0000] IFNα Subtypes in Normal Liver Tissue and PBMC in Healthy Individuals
[0057] After extraction of the total RNA of the normal liver tissue samples the RNAm of the IFNα was amplified using universal primers for all the IFNα subtypes. The PCR amplification products were then cloned and sequenced. 41 clones from 4 different normal livers were analysed and we observed that the IFNα sequence in the 41 clones was the same and corresponded to the IFNα5 subtype (Table 1). These results show that IFNα5 is the only IFNα subtype expressed in normal liver. The partial cDNA sequence of the IFNα5 obtained from all the clones was shown to be SEQ ID NO: 1.
[0058] To compare the profile of the IFN subtypes expressed in the liver with that expressed in PBMC the total RNA of the PBMC from 5 healthy controls was extracted and the IFNα RNAm was amplified with the universal primers for all the IFNα subtypes. Of the 43 clones analysed, 15 corresponded to the IFNα5 subtype, 14 to the IFNαl/13, 6 to the IFNα2l and 8 clones to other IFNα subtypes (Table 1). These results indicate that the IFNα subtype profile expressed in PBMC differs from that expressed in normal liver.
[0000] IFNα Subtypes in Liver Tissue and PBMC from Patients with Chronic Hepatitis C
[0059] The above results show that the normal liver expresses IFNα5, while PBMC express a variety of IFNα subtypes. In the liver parenchyma of patients with chronic hepatitis C there is mononuclear cell infiltrate, an important source of IFNα. This suggests that the profile of IFNα subtypes expressed by the liver in patients with chronic hepatitis C might differ from the profile found in normal liver. To investigate the expression of IFNα subtypes in chronic hepatitis C we extracted the total RNA from liver samples from 3 different patients and 2 PBMC samples. After amplifying the IFNα RNAm with universal primers for all subtypes, we cloned and sequenced 24 clones of liver tissue and 18 clones of PBMC. As shown in Table 1, the PBMC from patients with chronic hepatitis C expressed IFNα21, IFNα5 and IFNα7 (5, 12, and 1 clones respectively). In the liver tissue from these patients we found subtypes IFNα2l, IFNαl7 and IFNα1/13 (8, 1 and 2 clones respectively) in addition to the IFNα5 subtype (Table 1).
[0060] These data suggest that the production of IFNα by the mononuclear cell infiltrate can cause a change in the profile of IFNα subtypes expressed in the liver tissue of patients with chronic hepatitis C.
[0000] Levels of Expression of IFNα RNAm in PBMC and the Liver of Patients with Chronic Hepatitis C and Controls
[0061] Total RNA was extracted from PBMC and liver samples from patients with chronic hepatitis C (n=25 and 16, respectively), PBMC samples from healthy controls (n=20) and normal liver tissue samples obtained by laparotomy (n=12). The RNAm levels of IFNα were determined using the semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) technique using universal primers to amplify all the IFNα subtypes. The values are expressed as the ratio of IFNα RNAm to β-actin RNAm.
[0062] We found that the levels of expression of IFNα in the PMBC of patients with chronic hepatitis C were significantly increased in comparison with those found in healthy controls (3.2±0.48 against 1.14±0.26; p=0.001) ( FIG. 1A ). This result was expected in a viral infection such as hepatitis C in which the PBMC are infected (14). On the other hand the levels of expression of IFNα RNAm were significantly reduced in the liver tissue from patients with chronic hepatitis C in comparison with that expressed in normal liver (0.12±0.03 against 0.43±0.12; p=0.003) ( FIG. 1B ).
[0063] As observed previously, IFNα5 is the only IFNα subtype detected in normal liver, while a mixture of subtypes is observed in the liver tissue of patients with chronic hepatitis C. Our findings indicate that in infection by HCV there is a marked reduction in the expression of the IFNα subtype normally expressed in liver tissue. Interestingly, IFNα RNAm levels in the livers of patients with chronic hepatitis C show a direct correlation with the Knodell index (r=0.54; p<0.05). This finding, together with the observation that the IFNα subtypes detected in the livers of patients with chronic hepatitis C are those observed in PBMC suggests that most of the IFNα RNAm found in the liver in hepatitis C comes from the inflammatory infiltrate. It appears possible that the reduction in the expression of liver IFNα (IFNα5) may play a part in making the HCV infection chronic. As a result, these observations may have therapeutic implications if we also bear in mind the marked antiviral and antiproliferative activity of the IFNα5 described by other authors (9).
[0000] Levels of Expression of IFN RNAm in the PBMC and Liver of Patients with Chronic Hepatitis C and Controls
[0064] IFNβ, the second majority form of type 1 interferon, is a glycoprotein produced by a single gene. In viral infections transcription of the IFNα and IFNβ genes is activated or repressed by various mechanisms (15). To analyse the expression of IFNβ in chronic hepatitis C we determined IFNβ RNAm levels in the same samples of liver tissue and PBMC previously used to determine the expression of IFNα.
[0065] As shown in FIG. 2 , we observed that IFNβ RNAm levels (expressed as a ratio against β-actin) were significantly higher in both PBMC and the liver in patients with chronic hepatitis C in comparison with the PBMC findings in healthy controls and normal livers (1.66±0.2 against 0.88±0.16; p=0.008 in PBMC and 1.37±0.23 against 0.97±0.16; p=0.011 in liver). These results show that while HCV causes IFNα to be repressed in the liver, the expression of IFNβ is increased in both the liver and PBMC. This indicates that VHC modulates the different type I IFN genes in the liver in a different way, and blocks the production of IFNα to permit the overexpression of IFNβ.
[0000] Relationship Between the Expression of IFNα and IFNβ Genes with Viral Load, Genotype and Liver Damage in Chronic Hepatitis C
[0066] In order to determine whether the expression of the IFNα or IFNβ genes can be related to viral load or genotype we quantified the C virus RNA in the serum of all patients using the competitive PCR technique and determined the VHC genotype using a hybridization method with specific test materials. We found no correlation between the expression of the IFNα or IFNβ genes (in the liver or PBMC) and C virus RNA levels in serum or the viral genotype.
[0067] Analysing the relationship between the expression of the type I IFN genes and the severity of liver damage in patients with chronic hepatitis C we found that IFNβ RNAM levels in the liver correlated directly with serum aspartate aminotransferase values (r=0.64, p=0.008) and the Knodell index (r=0.66, p=0.006). Likewise the IFNα RNAm values in the liver showed a direct positive correlation with the Knodell index as mentioned previously.
TABLE 1 IFNα subtypes in controls and patients with chronic hepatitis C. Liver PBMC Control 1 9 IFNA5 clones Control 2 9 IFNA5 clones Control 3 11 IFNA5 clones Control 4 12 IFNA5 clones Control 5 3 IFNA5 clones 4 IFNA21 clones 2 IFNA1 clones Control 6 8 IFNA5 clones Control 7 10 IFNA1/13 clones 1 IFNA8 clone Control 8 3 IFNA5 clones 2 IFNA21 clones 2 IFNA1/13 clones 1 IFNA22 clones Control 9 2 IFNA10 clones 1 IFNA5 clone 1 IFNA2 clone 1 IFNA7 clone 1 IFNA8 clone 1 IFNA4 clone RNA-VHC (+) 6 IFNA5 clones 7 IFNA5 clones 1 2 IFNA21 clones 1 IFNA21 clone 1 IFNA17 clone 1 IFNA7 clone RNA-VHC (+) 2 IFNA5 clones 5 IFNA5 clones 2 4 IFNA21 clones 4 IFNA21 clones RNA-VHC (+) 5 IFNA5 clones 3 2 IFNA21 clones 2 IFNA1 clones
DESCRIPTION OF THE FIGURES
[0068] FIG. 1 : Expression of alpha interferon/β-actin RNAm (ordinate) in peripheral blood mononuclear cells (A) and in the liver (B) of healthy controls and patients with chronic hepatitis C (HCV-RNA+) (abscissa).
[0069] FIG. 2 : Expression of beta interferon/β-actin RNAm (ordinate) in peripheral blood mononuclear cells (A) and in the liver (B) of healthy controls (C) and patients with chronic hepatitis C (HCV-RNA+) (abscissa).
[0070] FIG. 3 : Relationship between the initial quantity of total RNA (abscissa) and the strength of the PCR product band obtained by amplifying the RNAm of IFNα (●), IFNβ (▴) and β-actin (♦) (ordinate, as counts×mm 2 ) in PBMC (A) and liver (B) samples.
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The invention relates to the use of interferon alpha 5 in the treatment of viral hepatopathies. The invention describes the reduced synthesis of IFNα5 in the livers of patients with hepatitis C in comparison to healthy livers. The sub-type of IFN expressed in said healthy livers corresponded only to the subtype alpha 5 in comparison with the different sub-types expressed in ill livers. The sequence SEQ ID NO:1 shows the partial sequence of cDNA corresponding to IFNα5. These significant differences between the expression patterns of some livers an others demonstrate the importance of the use of such interferon sub-type in the fabrication of compositions useful in the treatment of viral hepatopathies. The invention discloses in details such utilization in different forms and processes, including those which use the production of recombinant proteins from sequences of the type SEQ ID NO:1.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a lock core, particularly to one installed invisibly in all kinds of locks with an excellent anti-theft effect.
[0003] 2. Description of the Prior Art
[0004] Commonly, a conventional lock core is provided with a keyhole for a key to insert to lock or unlock the lock core. The lock core is provided with plural bayonets extended in the keyhole with diverse lengths, which are exactly engaged with grooves shaped around the key, so that the bayonets can push the lock core to rotate when the key is inserted and rotated in the keyhole, keeping other linked transmitting mechanisms moved to lock or unlock the lock core. But, such a lock core is actually not difficult to be unlocked by inserting an alternative pin, instead of the key, to push the bayonets. So, it is not a safe anti-theft lock.
SUMMARY OF THE INVENTION
[0005] The objective of this invention is to offer a lock core installed invisibly in a lock.
[0006] The main characteristics of the invention are a lock core base, a button, a cover, a connecting member, a bayonet base, a bayonet and two compression springs. The lock core base is provided with a chamber, a through hole bored in its one end to communicate with the chamber, an annular blocking surface formed at the boundary between the chamber and the through hole, and a threaded hole bored in its annular wall to communicate with the chamber. The button set in the lock core base is provided with a locking groove and a dead bolt member extended out from its one end. One of the compression springs is mounted around the dead bolt member, installed in the chamber. The cover installed at one end of the lock core base is provided with a through hole for the dead bolt member of the button to pass through. The connecting member is installed in the annular wall of the lock core base, provided with a through hole. The bayonet base connected with the connecting member is provided with a chamber and a through hole bored in its one end to communicate with the chamber. The bayonet inserted in the bayonet base is provided with a blocking flange and a connecting rod extended out from the blocking rim. The other compression spring is mounted around the connecting rod of the bayonet, installed in the chamber of the bayonet base.
BRIEF DESCRIPTION OF DRAWINGS
[0007] This invention is better understood by referring to the accompanying drawings, wherein:
[0008] FIG. 1 is an exploded perspective view of a preferred embodiment of a lock core in the present invention;
[0009] FIG. 2 is a perspective view of the preferred embodiment of a lock core in the present invention;
[0010] FIG. 3 is a cross-sectional view of the preferred embodiment of a lock core in the present invention;
[0011] FIG. 4 is a perspective view of a transmission, showing it being installed with the preferred embodiment of the present invention;
[0012] FIG. 5 is a cross-sectional view of the transmission installed with the preferred embodiment of the present invention, showing it being unlocked by the invention;
[0013] FIG. 6 is a cross-sectional view of the transmission installed with the preferred embodiment of the present invention, showing it being locked by the invention;
[0014] FIG. 7 is a perspective view of a door lock, showing it being installed with the preferred embodiment of the present invention;
[0015] FIG. 8 is a cross-sectional view of the door lock installed with the preferred embodiment of the present invention, showing it being unlocked by the invention;
[0016] FIG. 9 is a cross-sectional view of the door lock installed with the preferred embodiment of the present invention, showing it being locked by the invention; and
[0017] FIG. 10 is a perspective view of a safe deposit lock, showing it being installed with the preferred embodiment of present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] As shown in FIG. 1 , a preferred embodiment of a lock core in the present invention is composed of a lock core base 1 , a button 2 , a cover 3 , a connecting member 4 , a bayonet base 5 , a bayonet 53 and two compression springs 23 and 56 .
[0019] The lock core base 1 is provided with a chamber 10 , a through hole 11 bored in its one end to communicate with the chamber 10 , an annular blocking surface 12 formed at the boundary between the chamber 10 and the through hole 11 , female threads 13 formed at the other end of the chamber 10 , and a threaded hole 14 bored in its annular wall to communicate with the chamber 10 .
[0020] The button 2 is set in the lock core base 1 , provided with a locking groove 20 , an annular slot 21 formed in its one side, a dead bolt member 22 extended out from the annular slot 21 . The compression spring 23 is mounted around the dead bolt member 22 , installed in the chamber 10 .
[0021] The cover 3 installed at one end of the lock core base 1 is provided with male threads 30 , an annular slot 31 formed at its one side, and a through hole 32 bored in its center.
[0022] The connecting member 4 is installed in the annular wall of the lock core base 1 , provided with upper male threads 40 , lower male threads 41 and a through hole 42 opened through its center.
[0023] The bayonet base 5 connected with the connecting member 4 is provided with a chamber 50 , a through hole 51 bored in its one end to communicate with the chamber 50 , and female threads 52 formed at the other end. The bayonet 53 inserted in the chamber 50 is provided with a blocking flange 54 located near its intermediate portion, a connecting rod 55 extended out from the blocking flange 54 . The compression spring 56 is mounted around the bayonet 53 , installed in the chamber 50 .
[0024] In assembly, as shown in FIGS. 1-3 , the button 2 is first installed in the chamber 10 of the lock core base 1 , keeping its one end fitted in the through hole 11 of the lock core base 1 . Next, put the compression spring 23 on the dead bolt 22 , keeping one end of the compression spring 23 fitted in the annular slot 21 . The cover 3 is successively put on the compression spring 23 to keep the male threads 30 screwed with the female threads 13 of the lock core base 1 , so that the cover 3 is fixed together with one side of the lock core base 1 , enabling the dead bolt member 22 of the button 2 installed in the chamber 10 to extend out through the through hole 32 of the cover 3 , and the other end of the compression spring 23 is to be fitted in the annular slot 31 of the cover 3 . By the time, the button 2 is pushed by the compression spring 23 to keep its end surface positioned in a same plane of the end of the lock core base 1 . Then, the connecting member 4 is connected with the lock core base 1 via screwing the lower male threads 41 in the threaded hole 14 of the lock core base 1 . The compression spring 56 is mounted around the connecting rod 55 . Next, put the bayonet 53 , the connecting rod 55 and the compression spring 56 into the chamber 50 of the bayonet base 5 , keeping the connecting rod 55 extended out through the through hole 51 of the bayonet base 5 and the female threads 52 screwed with the upper male threads 40 of the connecting member 4 , so that the bayonet base 5 is fixed with the connecting member 4 . By the time, the bayonet 53 is inserted through the through hole 42 of the connecting member 4 . That is a complete assembly of the lock core.
[0025] In application, as shown in FIGS. 4 - 6 , the invention can be employed to lock or unlock a transmission 6 . When transmission 6 is to be locked, a user needs just to press the button 2 to keep the dead bolt member 22 moved into a passageway 61 of the transmission 6 . By the time, the compression spring 23 is compressed and the locking groove 20 is moved to a position exactly corresponding to the bayonet 53 , which is synchronously forced by the elasticity of the compression spring 56 to move into the locking groove 20 , keeping the button 2 positioned and the dead bolt member 22 extended into the passageway 61 to restrict a gear lever 60 of the transmission 6 from moving away from the parking gear, as shown in FIG. 6 . Therefore, the transmission 6 is locked, unable to be operated. When the transmission 6 is to be unlocked, a user can use a remote controller to enable an electric magnet 62 in the transmission 6 magnetized to attract a magnetic plate 63 connected with the end of the connecting rod 55 , as shown in FIG. 5 . While the magnetic plate 63 is being attracted by the electric magnet 62 , the bayonet 53 is to be synchronously moved to come off the locking groove 20 . The compression spring 23 in the chamber 10 of the lock core base 1 is to elastically push the 2 out as soon as the bayonet 53 moves away the locking groove 20 completely, spontaneously enabling the dead bolt member 22 to move away from the passageway 61 of the transmission 6 , keeping the gear lever 60 unrestricted. So, the transmission 6 can be operated again. With the lock core of the invention hidden in the transmission 6 and unlocked without a key, a thief cannot easily break it.
[0026] As shown in FIGS. 7-9 , the invention can be also applied in a door lock 70 installed in a door 7 . A control box 72 is set on the inside of a door frame 71 to face exactly to the door lock 70 , installed with a mechanism 73 inside it to drive a dead bolt 74 to act. The dead bolt 74 is bored with a hole 75 . In using, a remote controller is used to control the control mechanism 73 in the control box 72 to push the dead bolt 74 outward to pass into the door lock through an opening 76 , keeping the hole 75 positioned to face to the dead bolt member 22 rightly. Next, press the button 2 to enter the hole 75 of the locking bolt 74 , as shown in FIG. 9 . By the time, the compression spring 23 is compressed and the locking groove 20 is moved inward to a position exactly corresponding to the bayonet 53 , which is synchronously forced by the elasticity of the compression spring 56 to move into the locking groove 20 , keeping the button 2 positioned and the dead bolt member 22 extended into the hole 75 of the dead bolt 74 to keep the dead bolt 74 restricted immovably. So, the door 7 is locked unable to be opened. When the door lock 70 is to be unlocked, a user can also use a remote controller to enable an electric magnet 77 in the door lock 70 magnetized to attract a magnetic plate 78 connected with the end of the connecting rod 55 , as shown in FIG. 8 . While the magnetic plate 77 is being attracted by the electric magnet 78 , the bayonet 53 is to be synchronously moved off the locking groove 20 . The compression spring 23 in the chamber 10 of the lock core base 1 is to elastically push the button 2 out as soon as the bayonet 53 moves away the locking groove 20 completely, spontaneously enabling the dead bolt member 22 to move away from the hole 75 of the dead bolt 74 , keeping the dead bolt 74 unrestricted. And, by means of the control mechanism 73 installed in the control box 72 , the dead bolt 74 is pulled back in the control box 72 , then the door lock 70 is unlocked. With the lock core of the invention hidden in the door lock and unlocked without a key, a thief cannot easily break it, too.
[0027] In addition, as shown in FIG. 10 , the invention can be applied in a safe deposit 8 , installed and operated the same way as the previous embodiment is.
[0028] While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.
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A lock core includes a lock core base, a button, a cover, a connecting member, a bayonet base, a bayonet and two compression springs. It can be applied in diverse locks, such as a transmission lock, a door lock or a safe deposit lock etc, able to achieve an excellent anti-theft effect because it is installed invisibly, locked by just pressing a button and opened without a key and with a remote controller.
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CROSS-REFERENCE TO RELATED APPLICATION
The subject patent application claims the benefit of U.S. Provisional Application Ser. No. 60/149,917, which was filed on Aug. 23, 1999. The disclosure of that provisional patent application is hereby incorporated herein by reference.
FIELD OF INVENTION
The present invention is directed generally to a cable stay aerodynamic damper band and to its method of use. More specifically, the present invention is directed to a cable stay aerodynamic damper band that is usable with both new cables and as a retro-fit to existing cables. Most particularly, the present invention is directed to damper bands that are securable to cable stays in an application pattern that significantly reduces wind/rain or other induced vibrations in the cable. The cable stay aerodynamic damper bands are structured to be attached to or placed about both new cables as well as existing cables in a particular pattern or array. The use of these damper bands has been very effective in the substantial reduction and near elimination of wind/rain induced vibrations in cable stays and of vibrations induced by the passage of a fluid, such as air or water, over the surface of a cable. The damper bands have an aerodynamic shape that counteracts these vibrations or oscillation induced in the cable stay.
DESCRIPTION OF THE PRIOR ART
The use of cable stays in the construction of a wide variety of structures is well known. Any number of types of bridges use various cables to support bridge decks, to hold bridge towers steady and to generally form the support for the bridges. Suspension bridges are one example of a bridge structure that uses a large number of elongated cables as stays and supports. In a somewhat similar manner, cables are frequently used as guy wires or as stays in connection with tall antenna towers and the like. A large number of these towers are used to support various receivers, repeaters and other similar assembles. One need not look far without seeing such a tower. A plurality of elongated cables are typically run from various elevations on these towers to suitable ground anchors. These cable stays or guy wires are used to stabilize the tower.
Elongated cables are also utilized in the underwater stabilization of floating oil drilling installations. These cables are subjected to hydrodynamic forces that are very similar to the aerodynamic forces which above ground stay cables and guy lines experience.
In all of these cable applications, the passage of a fluid, such as air or water or of wind-driven rain, over the surface of the cable induces vibration or oscillation in the cable. If the fluid velocity is sufficient, the cable can be seen to vibrate at node points with sufficient amplitude that the structure with which the cable is associated may be damaged. In the case of bridge cable stays, the bridge stays may be caused to vibrate or in extreme situations to shake sufficiently that the structural integrity of the bridge may be compromised. Such vibrations can also cause fatigue in the cables. In the situation involving sub-sea cables, the position of the anchored platform can be affected with a resultant possible mis-alignment of platform supported drill strings and other similar downhole implements.
It has been proposed in the past to provide various mechanical vibration dampers for elongated cables. In one configuration, these vibration dampeners have taken the form of shock-absorber like devices that may be interposed between an end of the cable and an anchoring or attachment site for the cable. Other similar spring-biased connections have been used in the past in an effort to compensate for or to counteract wind/rain or high speed wind induced vibrations and oscillations.
Fairings and streamlining devices have, in the past, been applied to overhead cables, to sub-sea cables and to guy wires and cable stays. These attempt to altar the shape of the generally cylindrical cable to create an airfoil or flow-smoothing shape.
It is also known in the art to fabricate structures with integrally formed annular rings and with various projections and protrusions. In these structures, the rings are formed during the fabrication of the structure, which may be a mast of an outdoor antenna, a smokestack, transmission lines or pipelines. These rings are intended to reduce or to eliminate the vortex shedding which affects structures of these types. The elimination of this vortex shedding will greatly reduce the oscillating lateral forces which smokestacks, antennas, transmission lines and other cylindrical structure have been plagued by due to this periodic shedding of vortices.
While the prior art has appreciated the use of various vibration dampers and integrally formed annular rings and bands as well as various fairings and spoilers, there continues to exist a need for cable stay aerodynamic dampers and their method of use and application which will overcome the limitations of the prior art devices.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a cable stay aerodynamic damper band.
Another object of the present invention is to provide a method of using cable stay aerodynamic damper bands.
A further object of the present invention is to provide a cable stay aerodynamic damper band for retrofit use.
Still another object of the present invention is to provide a cable stay aerodynamic damper band which is effective in counteracting wind and rain induced vibration.
Yet a further object of the present invention is to provide a cable stay aerodynamic damper band which damps both low and high modal vibrations.
Even still another object of the present invention is to provide a cable stay aerodynamic damper band which is economical to use and which is easily attached.
As will be set forth in greater detail in the description of the preferred embodiments which are presented subsequently, the cable stay aerodynamic damper band in accordance with the present invention, and its method of use is primarily intended to counteract wind and rain induced vibrations in cable stays of structures, such as bridges and the like. It has been determined that the presence of small livers or rivulets of water running along the length of a cable stay, in combination with wind velocities in the range of 15-35 MPH can create very dramatic vibrations in the cable stay. These vibrations are not always the high modal vibrations such as would occur with high wind velocity directed perpendicularly to a taut cable or cylindrical structure and which typically create classic vortex shedding. Instead, these vibrations, which typically occur when the wind is coming from behind the cable, will typically cause first, second and third modes of vibrations. These wind/rain induced vibrations are clearly visible to the naked eye and thus are very unsettling to a motorist traveling across the bridge supported by these vibrating cable stays. More importantly, these low modal, violent vibrations can and do cause significant cable fatigue and other structural problems.
The existence of wind/rain induced vibrations in cable stays is a phenomenon that can be counteracted by properly designing the stay cables of a structure before it is erected. Unfortunately, there has not, in the prior art, been a practical retro-fit solution for bridges and cable stays which are already in place. The use of mechanical dampers at both ends of the cable is one current solution. Such mechanical dampers act as shock absorbers. They do nothing to prevent the wind/rain induced vibrations of the cable. They merely attempt to prevent it from being transmitted to the bridge structure. These mechanical dampers are large, expensive, heavy devices which are difficult to install and which have only a marginal amount of success.
Another current solution is to utilize a restrainer system in which adjacent cable stays are connected to each other by fixed length bars or stabilizers. This solution is again difficult and costly to implement, and may give rise to induced vibrations in adjacent cables. Further, the use of these restraint systems generally destroys the aesthetics of the bridge design.
The cable stay aerodynamic dampers bands, and their method of usage, in accordance with the present invention, provide an effective, cost efficient solution to the problem of cable stay vibration and particularly to wind/rain induced cable stay vibration. The cable stay damper bands utilize flexible or rigid cable encircling bands which carry embedded or attached tension straps. The cable encircling bands can be placed about existing cables in the field without taking the structure, such as a bridge out of service and without the need for large amounts of specialized equipment.
The cable stay aerodynamic damper bands of the present invention break up the rivulets or small rivers of water which tend to form on, and to travel along the cable stays. It is believed that these rivulets tend to act as an airfoil on the cable stays and that their existence is quite important to the generation of the low modal cable stay vibrations which the damper bands of the present invention have been so effective in reducing or eliminating. The damper bands of the present invention will also be effective in reducing or eliminating vortex shedding induced vibrations, such as the so called KARMAR VORTEX STREET vibrations. However, such higher mode vibrations typically 7th or 8th mode vibrations, are not as severe with respect to fatigue loadings as the lower mode wind/rain induced vibrations whose elimination is the primary problem to which the present cable stay aerodynamic damper bands are directed.
The damper bands of the present invention have been found to be very effective when applied to an existing cable stay in a pattern of bands placed along the cable at a spacing of preferably twice to four times the diameter of the cable. While this will result in the use of a large number of bands, the number of these bands is nowhere near the number suggested in the prior art as being required. The flexible or rigid bands can be installed effectively using uncomplicated techniques so that minimal disruption to the structure during damper band installation will occur.
Unlike prior proposed solutions, the cable stay aerodynamic damper bands of the present invention are not particularly conspicuous, do not require adjacent cables to be connected together, are durable and require essentially no maintenance, and are not apt to add a great amount of weight to the cable stays to which they are attached. The cable stay aerodynamic damper bands and their methods of use, in accordance with the present invention, overcome the limitations of the prior art solutions. They represent a substantial advance in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the cable stay aerodynamic damper bands and their method of use, in accordance with the present invention will be set forth with particularity in the appended claims, a full and complete understanding of the invention may be had by referring to the detailed description of the preferred embodiments, as will be set forth subsequently, and by referring to the accompanying drawings, in which:
FIG. 1 is a side elevation review of a portion of a cable stay carrying several of the damper bands in accordance with the present invention;
FIG. 2 is an enlarged view of the portion of the cable stay and damper band encircled in FIG. 1;
FIG. 3 is an end view of the cable of FIG. 1 showing a first embodiment of a damper band in accordance with the present invention;
FIG. 4 is a view similar to FIG. 3 and showing a second preferred embodiment of a damper band of the present invention;
FIG. 5 is a side elevation view of a third preferred embodiment of a cable stay aerodynamic damper band having a multi-segmented body;
FIGS. 6-8 are side elevation views of different segment shapes useable in the damper band of FIG. 5;
FIG. 9 is another view of the cable stay aerodynamic damper band of FIG. 5 now secured in place on a cable;
FIG. 10 is a view similar to FIG. 9 of a fourth preferred embodiment of a cable stay aerodynamic damper band of the present invention;
FIG. 11 is a graphical depiction of cable displacement in a wind/rain induced vibrating cable without and with the damper bands of the present invention; and
FIG. 12 is a graphical depiction of a wind induced cable stay vibration without and with the damper bands of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 1 there may be seen generally at 10 a first preferred embodiment of a cable stay aerodynamic damper band in accordance with the present invention. Damper band 10 is shown in place encircling a cable stay, generally at 12 . It will be understood that cable stay 12 is very schematically depicted and is intended to be representative of a large variety of cable stays. It will be readily apparent that such cable stays 12 are typically not one solid piece of metal but instead are a compound arrangement of numerous strands of material and other materials wound together and are sometimes filled with a grout or mortar-type material. Since cable stay 12 forms no part of the subject invention, it will not be discussed in detail. Suffice it to say that cable stay 12 has a cable diameter D and has a surface 14 which typically is not completely smooth but instead is a repeating pattern of helically extending peaks and valleys formed as the cable strands are wound together to form the resultant cable stay 12 or as durable pieces of tape are wound around the cables or the outer coverings, such as pipes, in which the cables may be contained.
Each cable stay aerodynamic damper band 10 is embodied to be placed about an existing cable; i.e. is primarily intended for retro-fit applications. The cable stay band 10 has a flexible body 16 which, as seen most clearly in FIG. 2, may be generally triangular in cross-section. A projection 18 may extend away from the apex 20 of the sides 22 and 24 of the generally triangular band 16 . The base 26 of the generally triangular shaped damper band 16 may include a resilient portion 28 . This resilient portion 28 will compensate for dimensional variations in the surface 14 of the cable 12 to which the bands are secured, and will also provide a watertight seal. A suitable elastic membrane may be placed on the base 26 of the band 16 to provide the band resilient portion 28 .
The damper band 10 shown in FIGS. 1 and 2 is depicted having a generally triangular-shaped band body 16 . It will be understood that this is representative of a number of band body cross-sectional shapes which could be used. The projection 18 on the band body 16 is instrumental in stopping the flow of rivulets of water and re-directing the wind flow along the length of the cable stay 12 to which the damper bands 16 are secured. It is also possible that the damper bands themselves, without the addition of the projections 18 will be effective in stopping the rivulet flow and in re-directing the wind flow along the cable 12 .
The body 16 of each damper band 10 is made of a suitable resilient, flexible material so that it will be able to be wrapped about the outer surface 14 of the cable stay 12 to which it is to be secured. The band has sufficient built-in tolerance or stretch so that it will form a tight compressive seal against the cable stay 12 whose diameter D is apt to vary slightly along its length. Any number of plastic or polymeric materials, which will exhibit the required built-in dimensional tolerances and which will tolerate long term exposure are suitable for use. The band may carry an elastic membrane as the resilient portion 28 that provides the watertight seal. In addition, elastic membranes may be placed at the ends 30 of the band body, as seen in FIG. 3 .
As is also shown in FIG. 3, which is not to scale, the damper band 10 is provided with an internally situated tension strap, generally at 32 . This tension strap 32 is used to secure the band body 16 to the cable surface 14 . This tension strap 32 can be plastic, metallic or of another suitable material and will produce a uniform, long term compressive hoop stress around the damper band body 16 . This tension strap 32 is provided with a male end 34 and a female end 36 , as seen in FIGS. 3 and 4. The tensioning strap 32 could be provided as a plastic wire tie, a metallic hose clamp or a similar elongated strap which will be embedded in, or pass along the body 16 of the damper band 10 .
As indicated above, the drawings depicting the subject invention are not to scale. The size of the damper bands has been increased for purposes of illustration. It has been determined that the size of the damper band 10 , with respect to the size of the cable stay 12 should be within certain ranges to produce the best results. The spacing S between adjacent damper bands 10 , as seen in FIG. 1 is determined by the relationship of S or band spacing being between two and four times the cable stay diameter D. Thus, if the cable stay has a diameter of 4½ inches, the band spacing S should be between 9 and 18 inches. Each band body 16 has a thickness t, as also shown in FIG. 1 . This thickness t should be selected to be in the range of between D/ 10 and D/ 20 . Again if the cable stay diameter is 4½ inches, the band thickness t should be between 0.45 inches and 0.225 inches.
Turning now to FIG. 4, there may be such a second preferred embodiment of a cable stay aerodynamic damper band, generally at 40 , in accordance with the present invention. In contrast to the damper band 10 which is made of a resilient, flexible material that will readily deform about the cable stay 12 , the damper band 40 , as shown in FIG. 4, may be made of a less flexible material. Two half circle band body segments 42 and 44 are secured to each other by a suitable hinge 46 . These band body segments 42 and 44 must still exhibit sufficient resiliency to accommodate variations in the cable stay diameter D along the length of the cable stay 12 . A watertight seal material 48 may again be placed along a base portion 50 of each of the band body segments 42 and 44 . This watertight seal material may not be required in all situations. Its useage will depend on both the cable stay and the ring material. The tensioning strap 32 is also provided, in the same manner as was discussed previously in connection with damper band 10 . The radially outwardly extending projection 18 described in connection with the first preferred embodiment 10 , is not shown in the second embodiment 40 . However, it is to be understood that this is for reasons of clarity. The projection 18 of band 10 could also be used with band 40 . The hinge 46 of cable stay aerodynamic damper band 40 could be as simple as a so-called living hinge or could be a more traditional hinge, depending on the size of the band body of the damper band 40 . As was the case with the first preferred embodiment 10 , the cross-sectional shape of the body of the damper band 40 can also be varied to suit the specific application. In both of these preferred embodiments, as well as in the several to be discussed shortly, the band body 16 or the band body segments 42 and 44 do not have to extend 360° around the surface 14 of the cable stay 12 .
A third preferred embodiment of a cable stay aerodynamic damper band, in accordance with the present invention, is shown generally at 60 in FIGS. 5 and 9. In this third preferred embodiment, the damper band 60 is comprised of a plurality of band body segments 62 . If, for example, a projection member, which is not specifically shown, is to be used with the damper band, and is to be made of metal, the band body segmented construction of FIGS. 5 and 9 will be advantageous. In this third embodiment, the watertight seal providing material is not specifically depicted and may not be required in all applications. As was the case with the previously described embodiment, this seal material will be usable to produce a good seal against the surface 14 of the cable stay 12 . The damper band 60 also has built-in tolerance allowances for slight changes in the cable stay diameter along the length of the stay. These can be accomplished by the provision of an elastic material on the end faces of the two band body segments 62 which will abut each other after the band has been placed about the cable stay. A suitable tension strap 64 is embedded in, or carried in the several band body segments 62 . This tension strap can be anchored at a first end 66 to a suitable anchor 68 and can have a second end 70 that will be receivable in a strap tightening fixture 72 . This tension strap 64 and its anchor 68 and strap tightener 72 will be similar to the corresponding structures described in connection with FIGS. 3 and 4.
The several band body segments 62 are connected together by a top linkage assembly, generally at 74 . The top linkage assembly 74 resists the outer pull-out force resulting from the tension strap 64 and holds the band body segments 62 in their correct orientation as the damper band 60 is placed about the cable stay 12 and the tension strap free or second end 70 is fed through the strap tightener 72 . Once the tension strap 64 has been tightened, the end or ends projecting out beyond the body segments can be cut off.
In the configuration shown in FIGS. 5 and 9, each of the band body segments 62 is generally trapezoidal in side view. This shape for a single band body segment 62 is shown in FIG. 6 . As may be seen there, the body segment 62 has somewhat arcuate inner and outer surfaces 76 and 78 , respectively. The radial side walls 80 are generally planar. The overall shape is generally similar to a keystone.
Alternative shapes for the band body segments 62 are shown in FIGS. 7 and 8. In both of these, the two radial walls 80 of each segment 62 are shaped to engage the adjacent radial wall of the next adjacent band body segment 62 . In FIG. 7, there are shown somewhat sinusoidal radial walls 80 . In FIG. 8 the radial walls have a cooperating shear key shape in which one radial wall 80 of each segment has a key 82 and the other radial wall 80 has a keyway 84 . It will be understood that other cooperating radial wall shapes are also within the scope of the present invention.
A fourth preferred embodiment of a cable stay aerodynamic damper band in accordance with the present invention is shown generally at 90 in FIG. 10 . In this fourth preferred embodiment, the damper band 90 has a band body 92 comprised of a plurality of similarly shaped band body segments 94 , which are generally the same as the band comprising segments 62 discussed in connection with the third preferred embodiment 60 . In this fourth preferred embodiment 90 , the tensioning strap 96 is tightened by a bolt 98 in a manner generally analogous to a hose clamp, as was discussed in connection with the first embodiment. A suitable removable cap 100 is provided so that the bolt head of the bolt 98 can be covered once the damper band 90 has been placed on the cable stay.
The cable stay aerodynamic damper bands in accordance with the present invention have proved to be very successful in reducing both wind/rain induced vibrations or oscillations, which are generally in the range of second or third modes of vibration, and also the vortex shedding induced vibrations or oscillations, which are more typically higher, such as seventh or eighth modes of vibration. Referring now to FIG. 11 there is shown a graph of cable stay vibration, charted as the root mean square of cable displacement in inches and as a function of wind speed. The x-axis scale of velocity of 100 to 200 units is equivalent to a velocity of 15-35 MPH for a typical cable stay. As will be seen, in a cable stay that is subjected to an upper rivulet; i.e. to a small stream of water extending along its length, the vibrational displacement is severe at a relatively low speed. At increased air or wind speeds, the wind/rain induced vibration is apt to dissipate because the formation of rivulets no longer occurs. However, in the more frequently occurring 15-35 MPH range, with rain, the cable stay vibration is very substantial. The addition of the aerodynamic damper bands or rings, as described above, has a very profound effect on reducing and virtually eliminating these wind/rain induced vibrations. Placement of the damper bands at spacings of either 2 times the cable diameter or 4 times the cable diameter greatly reduces the lower wind velocity wind/rain induced vibrations.
FIG. 12 demonstrates the effectiveness of the cable stay aerodynamic damper bands of the present invention in reducing the vortex shedding or other wind induced vibrations or oscillations that are apt to occur at higher wind velocities. As may be seen in FIG. 12 when the wind velocity increases to generally in the area of 50 MPH, i.e. to approximately 240 units as represented on the x-axis of the graph, the cable vibration created by this wind increases dramatically. The addition of the damper bands of the present invention, again at a spacing of two to four times the cable stay diameter will essentially eliminate these vibrations. Thus it can be seen that the retrofitting of an existing cable, or the installation on a new cable of the cable stay aerodynamic damper bands in accordance with the present invention, and at the spacing and size discussed above, is very effective in the virtual elimination of both lower mode of vibration wind/rain induced vibration as well as the higher mode of wind induced cable stay vibrations.
While preferred embodiments of a cable stay aerodynamic damper band and its method of use, in accordance with the present invention have been described fully and completely hereinabove, it will be apparent to one of skill in the art that a number of changes in, for example the overall size of the cable stay, the use to which the cable stay will be put, the material used to form the cable stay, and the like could be made without departing from the true spirit and scope of the present invention which is accordingly, to be limited only by the following claims.
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Wind/rain induced vibrations, as well as vortex shedding vibrations induced in a cable stay or a similar elongated, cylindrical element are dampened and substantially eliminated by applying a plurality of flexible damper bands to the cable at spaced intervals. The damper bands break up the formation of rivulets of water at lower wind speeds. These damper bands can be retrofit to existing cables or can be installed on new cables.
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RELATED APPLICATIONS
[0001] This application corresponds to PCT/EP2014/003127, filed Nov. 24, 2014, which claims the benefit of German Application No. 10 2013 020 618.9, filed Dec. 2, 2013, the subject matter of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a belt buckle for a vehicle seat belt.
[0003] A belt buckle is configured to receive and to lock a plug-in tongue arranged on a vehicle seat belt so as to prevent the plug-in tongue from being withdrawn from the belt buckle. For this purpose, the belt buckle includes a locking element adapted to interact with a recess within the plug-in tongue and thus locking the plug-in tongue inside the belt buckle. For transferring the locking element from a home position in which the plug-in tongue is not inserted to a locking position in which the plug-in tongue is inserted and locked, a locking mechanism being triggered by the plug-in tongue during insertion is provided. During insertion the plug-in tongue enters into contact with an ejection element disposed in the belt buckle and displaces the ejection element inside the belt buckle. The plug-in tongue is guided inside the belt buckle by the ejection element.
[0004] In the state of the art the ejection element typically includes activating springs triggering the locking mechanism when the plug-in tongue is inserted and accordingly the ejection element is displaced. Hence the locking element is released inside the casing and is displaced so that it engages in the recess of the plug-in tongue so as to inhibit the latter.
[0005] For releasing the plug-in tongue a release push-button is pressed. In this way the locking element is reset into the home position again, thus causing the plug-in tongue to be released again. Then the latter will be ejected from the belt buckle via the ejection element.
[0006] In the known belt buckles it has turned out to be a drawback that a clicking noise of the activating springs and a locking noise of definitely metallic nature will occur by the triggering of the locking mechanism via the activating springs and the locking by the locking element.
SUMMARY OF THE INVENTION
[0007] Therefore it is the object of the invention to design a belt buckle in such way that the noise during locking the belt buckle is reduced.
[0008] The object of the invention is achieved by a belt buckle for a vehicle seat belt comprising a frame in which at least one locking element adapted to lock a plug-in tongue insertable into the belt buckle and an ejection element adapted to eject the plug-in tongue are provided, wherein each of the ejection element and the locking element is adapted to adopt a locked position and a home position, the locking element being adjacent to the ejection element in the home position and thus being blocked in its home position. The principal idea of the invention consists in minimizing the noise occurring during locking by reducing the velocity of the locking element during locking. This will work due to the fact that the distance of the locking element from the home position to the locked position is minimized, as the locking element is directly adjacent to the ejection element. The lower velocity entails lower impact energy so that the noise occurring during locking is reduced. Moreover, a simpler structure is resulting as no complicated mechanism has to be provided for retaining the locking element in the home position. There is simply used the ejection element to retain the locking element in the home position.
[0009] Another aspect of the invention provides that the ejection element can be transferred by the plug-in tongue to the looked position in which the election element releases the locking element so that the locking element can reach the looked position and latch the plug-in tongue. According to the locking mechanism no activating springs triggering the locking mechanism are required at the ejection element. The clicking noise otherwise typically generated by the activating springs does not exist, causing the noise occurring altogether during locking to be further reduced. In addition, the assembly of the belt buckle is simplified, because the release mechanism for the looking element is definitely facilitated.
[0010] According to another aspect of the invention it is provided that the ejection element and/or the locking member are biased via a spring element, especially that the locking element is biased against the election element. It is ensured by the bias that the locking element, if released, passes into its locked position so as to guarantee safe latching of the plug-in tongue inside the belt buckle. This is independent of the mounting position of the belt buckle. Via the bias of the election element the inserted plug-in tongue may be ejected from the belt buckle in a simple manner.
[0011] Another aspect of the invention provides that the ejection element includes a web to which the locking element is adjacent in the home position. The length of the web allows adjusting when the locking element is released by the ejection element and passes to the locked position especially due to the bias. The web provided at the ejection element is typically configured corresponding to the length from the end of the plug-in tongue to the recess within the plug-in tongue so that the locking element can directly engage in the recess as soon as it is no longer retained in the home position by the ejection element.
[0012] Especially the ejection element substantially includes an H-shaped cross-section. The ejection element includes two webs connected approximately in the center by a cross web. At said cross web a stop surface for the plug-in tongue and, on the opposite side, a support surface for the spring element biasing the ejection element may be formed.
[0013] Another aspect of the invention provides a damping element adapted to interact with the locking element, especially by decelerating the movement of the locking element in a damping manner. The additional damping element causes the locking element to be decelerated in a comparatively smooth manner at the end of its adjustment travel from the home position into the locking position thereby the locking noise being further reduced.
[0014] According to an aspect of the invention, the damping element is arranged on a casing, especially on an inner surface of the casing. This facilitates the damping of the locking element, as the noise occurring during locking is mainly developed by interaction of the locking element and the casing.
[0015] Another aspect provides that the damping element is provided in an indentation in the casing, especially in an indentation facing the locking element. It is achieved in this way that the locking element directly impinges on the damping element when it passes into its locked position, thus causing the movement of the locking element to be decelerated and the locking element not to impinge on the casing. It is moreover ensured by the arrangement within the indentation that the ejection element may move unobstructed in the belt buckle.
[0016] According to an aspect of the invention, the damping element is a rubber or foam element, especially a PU foam element. These materials are especially well suited for decelerating the impact energy of the locking element and for simultaneously reducing noise.
[0017] Especially the damping element is formed of an injection-molded material that has been injected directly into the casing. In this way the damping element can be configured in a simple way during manufacture of the belt buckle casing.
BRIEF DESCRIPTION OF THE DRAWING
[0018] Further characteristics and advantages of the invention will be evident from the following description and the drawings which are referred to and in which:
[0019] FIG. 1 shows a cross-sectional view of a belt buckle according to the invention in the home position;
[0020] FIG. 2 shows the ejection element,
[0021] FIG. 3 shows another cross-sectional view of the belt buckle according to the invention in a first intermediate position while a plug-in tongue is inserted,
[0022] FIG. 4 shows another cross-sectional view of the belt buckle according to the invention in a second intermediate position with the plug-in tongue being further inserted, and
[0023] FIG. 5 shows the belt buckle of FIG. 1 with a plug-in tongue being locked therein.
DESCRIPTION
[0024] In FIG. 1 a belt buckle 10 is shown in a cross-sectional view in its home position. The belt buckle 10 includes a casing 12 formed of two casing shells 12 a, 12 b. In the casing 12 a locking mechanism is provided in a frame 14 constituting the self-supporting structure of the belt buckle 10 . The locking mechanism comprises at least one locking element 16 as well as one election element 18 .
[0025] The ejection element 18 illustrated in detail in FIG. 2 is arranged to be movable within the frame 14 and serves for ejecting a plug-in tongue inserted in the belt buckle from the same after pressing a release button at the belt buckle. For this purpose, the ejection element 18 interacts with a spring element 20 which loads the former into its home position (to the left in FIG. 1 ). The spring element 20 rests on a support surface 22 of the ejection element 18 and is supported on a casing part 23 .
[0026] A stop surface 24 serving as stop for a plug-in tongue not shown here is formed at the ejection element 18 opposite to the support surface 22 . The ejection element 18 further includes two webs 26 , 28 projecting from the stop surface 24 while facing each other. When a plug-in tongue is inserted in the belt buckle, its front end is located between the two webs 26 , 28 .
[0027] One of the two webs 28 , 28 is assigned to the locking element 16 so that it retains the locking element 16 in the home position when the ejection element 18 is provided in the home position.
[0028] On the front end of the webs 26 , 28 ramp-like bearing surfaces 26 a, 28 a are formed. The webs 26 , 28 in total have a pitch circle cross-section, wherein the surface assigned to the stop face 24 is planar.
[0029] The spring element 20 is adjacent the ejection element 18 , namely at the bottom of a receiving sleeve 29 which is integrally formed with the ejection element 18 on the side feeing away from the webs 26 , 28 . The webs 26 , 28 directly merge with the wall of the receiving sleeve 29 which receives the spring element 20 .
[0030] The locking element 16 , too, is biased into its looked position by means of a spring, namely by means of a spring element 30 ( FIGS. 3 to 5 ). By virtue of the bias the locking element 16 is pressed against the web 28 of the ejection element 18 assigned to the locking element 16 so that the locking element 16 is in direct contact with the ejection element 18 . The locking element 16 is retained in its home position against the bias by the ejection element 18 . For the purpose of contact the locking element 16 exhibits a contact face 31 that is inclined relative to its longitudinal orientation ( FIG. 2 ).
[0031] The spring element 30 may be in the form of a spiral spring, leaf spring or resilient member. In the illustrated embodiment the spring element 30 is in the form of a resilient metal strip.
[0032] Furthermore, a damping element 32 arranged in an indentation 34 of the casing shell 12 b is provided within the casing 12 . The damping element 32 is positioned opposite to the locking element 16 , wherein, in the home position of the belt buckle 10 , the ejection element 18 is located between the locking element 16 and the damping element 32 .
[0033] The damping element 32 may be a rubber or foam element which may have been injected into the indentation 34 during manufacture of the casing shell 12 b. As an alternative, it is provided that the damping element is in the form of an insertion member being glued into the casing shell.
[0034] When inserting a plug-in tongue 36 ( FIGS. 3 to 5 ) the front end 38 of the plug-in tongue provided with a recess 40 for the locking element 16 enters into contact with the ejection element 18 , causing it to be displaced by the plug-in tongue 36 inside the casing 12 . In this way, the belt buckle 10 in general, the locking element 16 and the ejection element 18 are transferred from their home positions into their locked positions as shown in FIG. 5 .
[0035] The belt buckle further includes, for releasing the plug-in tongue 36 , a push-button 42 adapted to be actuated for moving the locking element 16 via a link guide 44 against the bias of the spring element 30 .
[0036] The transition from the home position ( FIG. 1 ) to the locked position ( FIG. 5 ) takes place as follows, wherein the FIGS. 3 and 4 illustrate intermediate positions representing a sectional plane different from that of FIGS. 1 and 2 :
[0037] The plug-in tongue 36 is inserted into the belt buckle 10 ( FIG. 3 ). The plug-in tongue 36 enters into contact with the end 38 at the stop face 24 of the ejection element 18 and then pushes the election element 18 inside the belt buckle 10 to the right toward the casing part 23 .
[0038] During displacement of the ejection element 18 within the belt buckle 10 the spring element 20 arranged at the ejection element 18 is compressed. The locking element 16 first continues being adjacent to the ejection element 18 , especially to the web 28 , during displacement of the ejection element 18 .
[0039] When the election element 18 is displaced so far that the looking element 16 has arrived at the end of the web 28 , the looking element 16 slides over the contact face 31 inclined relative to its longitudinal orientation along the end of the web 28 into its locked position ( FIGS. 3 and 4 ). The sliding is further improved by the fact that the ramp-like bearing surface 28 a is configured to correspond to the contact face 31 at the end of the web 28 so that smooth sliding of the locking element 16 is resulting.
[0040] After the locking element 16 has slipped along the end of the web 28 , it is pressed through the recess 40 which then is arranged below the locking element 16 by the spring element 30 so that the plug-in tongue 38 is locked in the belt buckle 10 .
[0041] This movement is ensured by virtue of the bias by the spring element 30 so that it takes place independently of the mounting position. The movement of the locking element 16 during locking is reduced by the sliding at the end of the web 28 as, compared to the state of the art, the distance covered by the locking element 18 from the home position into the locked position without deceleration and under the effect of the spring element 30 is reduced. In this way the impact energy of the locking element arriving at the locked position is reduced. Thus the related noise is reduced.
[0042] At the end of the stroke into the locked position, the locking element 16 impinges on the damping element 32 , thus causing the impact energy to be partly taken up and absorbed by the damping element 32 . The occurring noise is further reduced in this way as the locking element 16 does not directly impinge on the casing 12 .
[0043] Upon actuation of the push-button 42 the locking element is moved over the link guide 44 and is disengaged from the recess 40 of the plug-in tongue 36 again. Due to the bias of the spring element 20 , then the ejection element 18 is loaded into its home position ( FIG. 1 ) again and the socking element 16 is adjacent to the ejection element 18 .
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The invention describes a bell buckle ( 10 ) for a vehicle seat belt comprising a casing ( 12 ) in which at least one locking element ( 16 ) adapted to lock a plug-in tongue insertable into the belt buckle ( 10 ) and an ejection element ( 18 ) adapted to eject the plug-in tongue are provided. Each of the ejection element ( 18 ) and the locking element ( 16 ) is adapted to adopt a locked position and a home position, wherein in the home position the locking element ( 16 ) is adjacent to the ejection element ( 18 ) and thus is blocked.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a linear guide bearing apparatus for use in, for example, industrial machines.
[0002] For example, an apparatus shown in FIG. 7 is known as a related linear guide bearing apparatus of such a kind (see, for instance, Patent Document 1).
[0003] This linear guide bearing apparatus has a guide rail 1 extending in an axial direction, and a slider 2 bridged across the guide rail 1 to be able to be displaced with respect thereto in the axial direction. Two rows of rolling-element rolling grooves 3 extending in the axial direction are formed in each of both widthwise side surfaces of the guide rail 1 , so that a total of four rolling-element rolling grooves 3 are formed.
[0004] Rolling-element rolling grooves 5 respectively opposed to the rolling-element rolling grooves 3 are formed in the inner side surfaces of both sleeve portions 4 of the slider body 2 A of the slider 2 . These rolling-element rolling grooves 3 and 5 constitute a load raceway.
[0005] Many cylindrical rollers 6 serving as rolling elements are rollably loaded into the load raceway. Rolling of the rollers 6 enables the slider 2 to be displaced on the guide rail 1 in the axial direction with respect thereto.
[0006] As the slider 2 is displaced, the cylindrical rollers 6 intervening between the guide rail 1 and the slider 2 roll and move to an axial end of the slider 2 . However, it is necessary for consecutively moving the slider 2 in the axial direction to endlessly circulate these cylindrical rollers 6 .
[0007] Thus, cylindrical holes 7 axially penetrating through the sleeve portions 4 of the slider body 2 A are formed. Circulating sleeves 8 , the inside of each of which is used as a path (a rolling element path) 8 a for the cylindrical roller 6 , are fitted into these holes 7 . Also, end caps 9 are respectively fixed to both axial ends of the slider body 2 A by screws. A direction change path 10 , which is curved like an arc and communicates between the load raceway and the rolling element path 8 a is formed in each of the end caps 9 . Thus, an endless raceway for the cylindrical rollers 5 is formed.
[0008] Incidentally, the direction change path 10 communicating between the upper rolling-element path 8 a and each of both the lower rolling-element rolling grooves 3 and 5 is disposed to cross the direction change path 10 , which communicates between the lower rolling-element path 8 a and each of both the upper rolling-element rolling grooves 3 and 5 , in a grade separation manner.
[0000] [Patent Document 1] JP-A-2002-54633.
[0009] In the related linear guide bearing apparatus, the rolling element path 8 a of each of the circulating sleeves 8 fitted into the holes 7 of the slider body 2 A is a path for the cylindrical roller 8 and is cross-sectionally rectangular. Thus, it is necessary for forming the endless circulating raceway that when the circulating sleeves 8 are inserted into the holes 7 , an operation of carefully inserting or turning the circulating sleeves 8 is performed so that the phase of each of the circulating sleeves 8 is adjusted to an appropriate value with respect to the associated hole 7 . The related linear guide bearing apparatus has a drawback in that this operation is troublesome.
SUMMARY OF THE INVENTION
[0010] The invention is accomplished to solve the drawback. An object of the invention is to provide a linear guide bearing apparatus enabled to easily achieve an operation of adjusting the phase of the circulating sleeves and also enabled to smoothly perform assembly thereof.
[0011] To achieve the foregoing object, according to a first aspect of the invention, there is provided with a linear guide bearing apparatus including a guide rail, which has a rolling element rolling groove axially extends, and a slider, which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail and is bridged across the guide rail to be able to be axially displaced with respect thereto by rolling a large number of rollers serving rolling elements, and which are inserted into a load raceway formed between the rolling element rolling grooves. The slider includes a slider body, in which a circulating sleeve is fitted into each of holes axially penetrating therethrough and has an inner part used as a rolling element path, and an end cap that has a curved direction change path communicating between the load raceway and the rolling element path and that is fixed at an axial end portion of the slider body. The first aspect linear guide bearing apparatus features that a projecting portion extending along an axial end surface of the slider body is provided at least at one of the circulating sleeves.
[0012] According to the second aspect of the invention, there is provided with the linear guide bearing apparatus according to the first aspect, further including a concave portion, into which the projecting portion is fitted, provided in the end cap, wherein a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the projecting portion into the concave portion.
[0013] According to the third aspect of the invention, there is provided with the linear guide bearing apparatus according to the first or second aspect, wherein the projecting portion constitutes a part of the direction change path.
[0014] According to a fourth aspect of the invention, there is provided with the linear guide bearing apparatus according to the first aspect, further including a concave portion provided in an axial end portion of the slider body, and a convex portion to be fitted into the concave portion provided on the projecting portion, wherein a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the convex portion into the concave portion.
[0015] According to a fifth aspect of the invention, there is provided with the linear guide bearing apparatus according to one of the first to fourth aspects, wherein the circulating sleeve with the projecting portion includes a first circulating sleeve constituent member and a second circulating sleeve constituent member, into which the circulating sleeve is split along a central axis thereof, and a color for discriminating between the first circulating sleeve constituent member and the second circulating sleeve constituent member is applied to at least one of the first circulating sleeve constituent member and the second circulating sleeve constituent member.
[0016] According to a sixth aspect of the invention, there is provided with a linear guide bearing apparatus including a guide rail, which has a rolling element rolling groove axially extends, and a slider, which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail and is bridged across the guide rail to be able to be axially displaced with respect thereto by rolling a large number of rollers serving rolling elements, and which are inserted into a load raceway formed between the rolling element rolling grooves. The sixth aspect linear guide bearing apparatus features that a color for discriminating paired components, which have object shapes, among components of the linear guide bearing apparatus, is applied to at least one of the paired components.
[0017] According to the first aspect linear guide bearing apparatus of the invention, application of torque, which is used for rotating the circulating sleeve, to the projecting portion is facilitated by operating the projecting portion, which is provided at least at one of the circulating sleeves and extends along the axial end surface of the slider body, after the circulating sleeve is inserted into the hole of the slide body. Consequently, an operation of adjusting the phase of the circulating sleeve with respect to the hole of the slider body is facilitated.
[0018] Also, even in a case where the circulating sleeve is firmly fixed in the hole of the slider body by intermediate-fitting or interference-fitting so as to increase the stiffness of the circulating sleeve and as to suppress the vibrations and the noises, the torque causing the circulating sleeve to be fitted into the hole to rotate can be applied by utilizing the projecting portion. Consequently, the operation of adjusting the phase of the circulating sleeve can easily be performed.
[0019] The second aspect linear guide bearing apparatus features that a concave portion, into which the projecting portion is fitted, is provided in the end cap, and that a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the projecting portion into the concave portion, in addition to the features of the first aspect linear guide bearing apparatus of the invention. Thus, when the apparatus is fabricated, the phase of the circulating sleeve can easily be adjusted.
[0020] The third aspect linear guide bearing apparatus of the invention features that the projecting portion constitutes a part of the direction change path, in addition to the features of the first or second aspect linear guide bearing apparatus of the invention. Thus, the number of the components can be reduced. Also, the step-like parts in the circulating path, in which the rolling elements are circulated, are reduced. Consequently, the rolling elements can smoothly be passed therethrough.
[0021] The fourth aspect linear guide bearing apparatus of the invention features that a concave portion is provided in an axial end portion of the slider body, that a convex portion to be fitted into the concave portion is provided on the projecting portion, and that a phase of each of the circulating sleeves with respect to the slider body is adjusted by fitting the convex portion into the concave portion, in addition to the features of the first aspect linear guide gearing apparatus of the invention. Thus, when the apparatus is fabricated, the phase of the circulating sleeve can easily be adjusted.
[0022] Also, because the concave portion serves as a mark indicating the hole, into which the circulating sleeve is inserted, the circulating sleeve can be prevented from being inserted into the erroneous hole.
[0023] The fifth aspect linear guide bearing apparatus of the invention features that a color for discriminating between the first circulating sleeve constituent member and the second circulating sleeve constituent member is applied to at least one of the first circulating sleeve constituent member and the second circulating sleeve constituent member, in addition to the feature of one of the first to fourth aspect linear guide bearing apparatuses. Thus, the first circulating sleeve constituent member and the second circulating sleeve constituent member can be discriminated from each other at a glance and also can be combined with each other.
[0024] The sixth aspect linear guide bearing apparatus of the invention features that a color for discriminating paired components, which have object shapes, among components of the linear guide bearing apparatus, is applied to at least one of the paired components. Thus, the paired components of the linear guide bearing apparatus can be discriminated from each other at a glance and also can be combined with each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is an embodiment of the invention.
[0026] FIG. 2 is an explanatory view illustrating the configuration of a circulating sleeve shown in FIG. 1 .
[0027] FIG. 3 is a left side view illustrating the circulating sleeve shown in FIG. 1 .
[0028] FIG. 4 is a view partly illustrating an end cap.
[0029] FIG. 5 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is another embodiment of the invention.
[0030] FIG. 6 is a view partly illustrating an axial end surface of a slider body.
[0031] FIG. 7 is a partly cutaway explanatory view illustrating a related linear guide bearing apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereinafter, an embodiment of the invention is described with reference to the accompanying drawings. FIG. 1 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is an embodiment of the invention. FIG. 2 is an explanatory view illustrating the configuration of a circulating sleeve shown in FIG. 1 . FIG. 3 is a left side view illustrating the circulating sleeve shown in FIG. 1 . FIG. 4 is a view partly illustrating an end cap. FIG. 5 is an explanatory view illustrating a primary part of a linear guide bearing apparatus that is another embodiment of the invention. FIG. 6 is a view partly illustrating an axial end surface of a slider body. Incidentally, in this embodiment, parts, which are the same as or correspond to those described by referring to FIG. 7 , are designated by the same reference characters used in FIG. 7 . Thus, the description of such parts is omitted herein.
[0033] As shown in FIGS. 1 to 3 , a linear guide bearing apparatus, which is an embodiment of the invention, has a projecting portion 20 that is provided at an end portion of a circulating sleeve 8 and extends along an axial end surface of a slider body 2 A.
[0034] The circulating sleeve 8 including the projecting portion 20 is split along a central axis thereof into and comprises two parts, that is, a first circulating sleeve constituent member 8 R and a second circulating sleeve constituent member 8 L. A positioning convex portion 11 and a positioning concave portion 12 are respectively formed at a position on the splitting surface of one of the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L, and at a position in that of the other sleeve constituent member so that the position of the convex portion 11 corresponds to the position of the concave portion 12 when the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L are fitted to each other. The circulating sleeve 8 is formed by superposing the splitting surfaces of first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L so that the positioning convex portion 11 , which is formed at a position on the splitting surface of one of the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L, is fitted into the positioning concave portion 12 formed in that of the other sleeve constituent member. A rolling element path 8 a is formed in the circulating sleeve 8 . During this state, the circulating sleeve 8 is inserted into a hole 7 of the slider body 2 A. A color is applied to the entirety of at least one of the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L. This color enables that the first circulating sleeve constituent member 8 R and the second circulating sleeve constituent member 8 L can be discriminated from each other at a glance and also can be combined with each other. In this case, when the circulating sleeve constituent members 8 R and 8 L are formed of resin materials, preferably, a method of applying a color thereto is to apply a color directly to each of the resin materials. In a case where the circulating sleeve constituent members 8 R and 8 L are formed of metallic materials, and where it is difficult to apply a color directly to each of the metallic materials, the color may be applied to the members 8 R and 8 L by performing secondary processing, such as painting.
[0035] Also, application of torque, which is used for rotating the circulating sleeve 8 , to the projecting portion 20 is facilitated by operating the projecting portion 20 after the circulating sleeve 8 is inserted into the hole 7 of the slide body 2 A. Consequently, the adjustment of the phase of the circulating sleeve 8 with respect to the hole 7 of the slider body 2 A is facilitated.
[0036] Even in a case where the circulating sleeve 8 is firmly fixed in the hole 7 of the slider body 2 A by intermediate-fitting or interference-fitting so as to increase the stiffness of the circulating sleeve 8 and as to suppress the vibrations and the noises, the torque causing the circulating sleeve 8 to be fitted into the hole 7 to rotate can be applied by utilizing the projecting portion 20 . Consequently, an operation of adjusting the phase of the circulating sleeve can easily be performed.
[0037] Also, in this embodiment, an inner periphery side raceway 10 a of a direction change path 10 is formed in the projecting portion 20 so as to reduce the number of components. In this case, as shown in FIG. 4 , a positioning concave portion 30 , whose bottom part is formed as an outer periphery side raceway 10 b , is provided in the end cap 9 . The projecting portion 20 is fitted into this positioning concave portion 30 to thereby adjust the phase of the circulating sleeve 8 with respect to the hole 7 of the slider body 2 A. Thus, the phase of the circulating sleeve 8 can easily be adjusted at fabrication of the apparatus.
[0038] Also, the projecting portion 20 is formed integrally with the inner periphery side raceway 10 a of the direction change path 10 . Thus, step-like parts in the path, in which the cylindrical rollers 6 are circulated, can be reduced. Consequently, the cylindrical rollers 6 can smoothly be passed therethrough.
[0039] In this embodiment, a projection 32 is provided at the other end portion of the circulating sleeve 8 so that the projection 32 is fitted into a hole 31 (see FIG. 4 ) provided in the opposite end cap 9 . The circulating sleeve 8 is more firmly fixed by fitting the projection 32 into the hole 31 .
[0040] Incidentally, the linear guide bearing apparatus of the invention is not limited to the aforementioned embodiment. The embodiment can appropriately be altered without departing from the spirit and scope of the invention.
[0041] For example, although the foregoing description of the embodiment has described the case that the phase of the circulating sleeve 8 with respect to the hole 7 of the slider body 2 A is adjusted by fitting the projecting portion 20 at the side of the circulating sleeve 8 into the positioning concave portion 30 provided in the end cap 9 , instead, the following configuration may be employed. That is, as shown in FIGS. 5 and 6 , a convex portion 40 is provided on a side of the projecting portion 20 of the circulating sleeve 8 , which faces an axial end surface of the slider body 2 A. Also, a concave portion 41 , into which the convex portion 40 is fitted, is provided in the axial end surface of the slider body 2 A. The phase of the circulating sleeve 8 with respect the hole 7 of the slider body 2 A is adjusted by fitting the convex portion 40 into the concave portion 41 .
[0042] Referring to FIG. 6 , in this case, the concave portion 41 serves as a mark indicating the hole 7 (the lower one, as viewed in FIG. 6 ), into which the circulating sleeve 8 is inserted. Thus, the circulating sleeve 8 can be prevented from being inserted into the erroneous hole 7 (the upper one, as viewed in FIG. 6 ). Incidentally, the circulating sleeve 8 is inserted from an opposite side into the upper hole shown in FIG. 6 . Similarly, the convex portion 40 provided in the projecting portion 20 of the circulating sleeve 8 is fitted into the concave portion 41 of the slider body 2 A.
[0043] Also, although the foregoing description of the embodiment has described the case, in which a color is applied to at least one of paired right circulating sleeve members 8 R and 8 L, by way of example, the invention is not limited to this case. A color is applied to at least one of paired components, which have symmetric shapes, among components of the linear guide bearing apparatus so as to discriminate the paired components from each other. Thus, the invention can obtain effects of smoothly performing the fabrication of the linear guide bearing apparatus. Additionally, it is unnecessary to apply the color to the entirety of each of the components. A color may be applied to positions or a range on a part of each of the components so that the components can easily and visually be checked.
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It is a linear guide bearing apparatus comprising a slider 2 that has a slider body 2 A provided with a holes 7 , into which a circulating sleeve 8 , whose inside space serves as a rolling-element path 8 a, is fitted, and also has an end cap 9, which has a curved direction change path 10 communicating between a load raceway and a rolling-element path 8 a and is fixed to an associated axial end portion of the slider body 2 A. The linear guide bearing apparatus further comprises a projecting portion 20, which is provided at least at one of end portions of the circulating sleeve 8 and extends along the axial end portion of the slider body 2 A.
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BACKGROUND OF THE INVENTION
This invention relates to a machine for forming large round bales of fibrous agricultural crops. More particularly, I provide a latching mechanism which senses the pressure being applied to compress the bale while at the same time holding the bale discharge gate closed.
An application titled "Latching Mechanism for a Round Baler" having Ser. No. 282,548 and assigned to the same assignee is made copending with this one by simultaneous submission.
Many bale forming machines exist which form fibrous agricultural crops into bales that are either twine or wire tied. For example, the U.S. Pat. No. 4,009,653 to Sacht discloses a method for forming large round bales in a machine comprising a cage-like frame having a horizontal axis and a generally cylindrical shaped baling zone. Upwardly extending machine sidewalls form the confining end surfaces of the baling zone. A plurality of serially arranged conveying elements enclose and generally define the circumferential periphery of the baling zone. Thus, the size of the baling chamber remains constant during the bale forming process. To accomplish discharge of a completed bale, the baling chamber is divided into two portions approximately along a vertically extending axis cutting plane. The rear portion of the housing is then configured to swing upward from a hinge point at the top, thereby allowing the bale to be discharged rearward.
The U.S. patent application having Ser. No. 162,372, now U.S. Pat. No. 4,319,446, and assigned to the same assignee as this application discloses bale forming means which differ somewhat from the implementation of Sacht. Two additional rollers are added to support the bottom conveyor belts. As viewed from the side the improved system shows four rollers on which a plurality of laterally spaced belts are trained. The second and third rollers (which are respectively in the forward and aft portions of the conveyor midsection) and the fourth roller (which is at the rear of the machine) are disposed to be generally on the cylindrical periphery of the baling zone. The first roller is in front of and somewhat below the plane containing the axis of the third roller. The Arnold etal, invention improves on Sacht in two ways. First, the vertical dimension of the entrance throat is enlarged. This allows the baler to operate in a heavier stand of hay without becoming clogged. Second, by lowering the placement of the front roller, a pickup reel of smaller diameter can be used. This permits the flow of hay being picked up from the windrow to pass into the baling zone without undergoing abrupt changes in direction. The laterally spaced conveyor belts accept the crop material being passed on from the pickup reel and frictionally engage the crop strands to provide inward directed pressure to carry them into the baling zone.
This invention is shown in conjunction with a baler having a bottom conveyor member for receiving agricultural material which is constructed similar to that disclosed in the U.S. patent application having Ser. No. 162,372. Using this type of bottom conveyor, generally cylindrical bales are formed in a cavity of fixed size. The partially completed bale rotates on a horizontal axis while crop material picked up from a windrow is continuously added to the periphery of the bale. As the baling chamber fills, pressure is exerted on the surrounding enclosure. The enclosure is hinged along the top edge to allow the rear portion to open upwardly to enable discharge of a completed bale. I provide a latch mechanism to hold the opposing faces of the enclosure together until the bale is complete.
With my invention the tailgate is mechanically locked in the closed or baling position by adjustable spring loaded latches, one on each side of the baler. As the baling chamber fills, pressure on the tailgate causes a latch slide to compress a spring. Excursion of the latch slide gradually forces the tailgate to come away from its nesting position by as much as an inch. The movement of the tailgate in response to internal pressure is monitored by mechanical and/or graduated electrical sensors to generate visual and audible indications of the bale forming status. Latch release is interlocked with the hydraulic door cylinder linkage which actuates at the initiation of the bale discharge sequence. With my implementation there are no hydraulic pressure gauges to be monitored and small hydraulic leaks will not effect performance.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a latching mechanism which senses when the bale density has reached a specified level. It is another object of the invention to provide the machine operator with a signal that the bale is ready for discharge from the baling chamber.
The baler with which the latching mechanism was first reduced to practice forms generally cylindrical bales in a chamber of fixed size. During the bale forming process, the partially completed bale rotates on a horizontal axis while crop material picked up from a windrow is continuously added to the periphery of the bale. As the baling chamber fills pressure is exerted on the peripheral elements of the enclosure. The enclosure is hinged along the top edge to allow the rear portion to swing upward, forming thereby a tailgate through which a completed bale can be discharged.
The latch mechanism holds the opposing front and rear portions of the enclosure together during the bale forming operation. Two latches are used, one on each side, near the bottom juncture of the enclosure. Each latch is mechanically interlocked with a hydraulic cylinder which spans the front to rear faces of the baler sidewalls near a mid-height location. These cylinders are operated in synchronism from the tractor hydraulic system and serve to raise and lower the tailgate. By interlocking each latch mechanism with that hydraulic cylinder which is on the same side of the baler, latch release is assured before the piston of the hydraulic cylinder extends to raise the tailgate. Since the hydraulic cylinders are energized in parallel, the latches will release in synchronism.
Each latching mechanism includes components, some of which are secured to the front sidewall of the baler and some of which are secured to the rear sidewall of the baler. On the front is a bracket which is secured to the sidewall. A latch slide projects rearward through an aperture in the bracket. The latch slide is spring loaded against the bracket and retained in position by keeper pins. The rearmost end of the latch slide extends beyond the rear edge of the front sidewall and terminates in an offset knob. A locking hook journalled at one end to the lower rear sidewall is positioned so that its second end engages the knob portion of the latch slide.
When the locking hook and the latch slide on both the left and right sides of the baler are locked together, the tailgate is held in the closed condition. As the baling chamber fills with crop material, pressure is exerted on the latches. The spring loaded latch slides extend under this pressure allowing the tailgate to come slightly ajar. As the pressure from the baling chamber builds up, the gap between the front and rear edges of the lower sidewalls becomes larger due to compression of the springs. The magnitude of the gap is sensed and when it exceeds a predetermined value, the bale discharge sequence in initiated.
The first thing that is done in the bale discharge event is the release of the tailgate latches. This is done by mechanically interlocking the latching hooks and the hydraulic cylinders used to raise the tailgate. By interlocking the two functions, the latch assemblies are disconnected whenever the hydraulic cylinders are energized to raise the tailgate. Lowering the tailgate after discharge of the bale has been completed results in reclosure of the latches.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left side view of a baler which incorporates the latch assembly.
FIG. 2 is a cutaway right side view of the baler showing the layout of the conveyor assemblies which surround the baling chamber.
FIG. 3 is a side view of the latch assembly positioned for the case where the baler tailgate has just been closed.
FIG. 4 is an enlarged view of the latch mechanism showing its elongated status representative of the baling chamber being filled with hay.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, there is shown a baler 10 which is conventional in all respects with the exception of the tailgate latch assembly. Baler 10 forms cylindrically shaped round bales 12 (See Fig. 2) from windrowed fibrous crop material. The machine consists of a single axle chassis 14 supported on wheels 16 and tractor hitch 18. A gear box unit 20 receives operating power from the tractor via a power take off shaft (not shown).
The baling chamber is divided into two parts. There is a front part having front sidewall 22 and a rear part having rear sidewall 24. As shown in the cutaway view of FIG. 2, the circumference of the baling chamber is surrounded by a number of conveyor assemblies. The bottom conveyor 26 is comprised of a multiplicity of side by side belts which are entrained on four transversely extending parallel rollers 27, 28, 29 and 30. The bottom conveyor is powered to move rearward as shown by arrow 32, carrying crop material into the baling chamber that has been gathered by pickup reel 34. Above the bottom conveyor, there are a number of other conveyor elements. FIG. 2 shows three in the rear part and two in the front part. In the unit reduced to practice, all upper conveyor assemblies were alike. Each was comprised of a multiplicity of side by side belts entrained on a pair of transversely mounted rollers. The downstream roller of each pair was powered by a sprocket and chain drive as shown in FIG. 1 where chains 35, 36, 37 and 38 serially receive power from one another and from gear box 20 via chain 40. Pickup reel 34 is powered from the same source.
At the upper end of rear sidewall 24, the rear part of the baling chamber is journalled at the axle of roller 42 so that it can be pivoted or swung upward approximately 90 degrees into the discharge position shown dotted in FIG. 1. Raising and lowering of the rear part around the pivot point is accomplished by hydraulic cylinders 44, one on each side of the baler. The front end of hydraulic cylinder 44 is rotatably anchored in front sidewall 22 by bolt 46. The second end is secured by bolt 48 to one arm of bell crank 50 whose center is attached to rear sidewall 24 by bolt 52. The bell crank serves to actuate the latch which secures the rear part of the baler to the front.
It will be understood that there are identical latch assemblies on each side of the baler. Those latch assemblies are released when cylinders 44 are energized to raise the rear tailgate. FIGS. 1 and 3 show how the latch assemblies operate. The second arm of bell crank 50 is connected via a coupling rod 56 with locking hook 58. The locking hook is journalled at one end to the lower rear sidewall 24 by pin 60. The second end of locking hook 58 is positioned so as to engage the knob end of latch slide 62. Latch slide 62 is secured to front sidewall 22 by means of bracket 64 which has an aperture therein, through which the central barrel of latch slide 62 can readily move. To the left of bracket 64 as seen in FIG. 3, is a multiple turn coil spring 66 and a keeper washer 68 which together with stop bolt 70 tend to hold the latch slide 62 so that keeper pin 72 rests against the face of bracket 64. Spacer shims can be inserted between keeper washer 68 and multiple turn coil spring 66 to attain exact preloading of latch slide 62 when engaged by locking hook 58. Keeper pin 72 is positioned such that latch slide 62 extends far enough past the rear edge of part 22 (See dashed line 73) to allow the knob end thereof to be engaged by locking hook 58. Tension spring 74 ensures a constant automatic locking action. A roller 76 on the locking hook 58 serves to minimize friction between the mating surfaces. Roller 78 secured to sidewall 24 helps to keep latch slide 62 properly aligned, counteracting the latch closing force of spring 74.
When it is desired to open the tailgate of the baler, hydraulic pistons 44 will be actuated. As they extend, bell crank 50 will rotate around bolt 52 until the upper arm intercepts block 54. This movement of the bell crank raises the latching hook 58 sufficiently so that it clears the knob end of latch slide 62. With the latches on both sides of the baler thus disengaged, subsequent extension of pistons 44 serves to raise the tailgate to the position shown in FIG. 3.
The spring loaded latch slide shown in FIG. 3 enables a function to be accomplished which was not possible with prior art machines. This has to do with sensing of the quantity of crop material that is in the baling chamber. As the bale grows in size, the belts surrounding the periphery of the chamber begin to exert an inward directed pressure on the bale. As the pressure increases, the latches holding the tailgate closed, receive more strain. My invention allows this strain to be measured. FIG. 4 shows the means for accomplishing this. Longitudinal strain on latch slide 62 compresses spring 66 allowing baler sidewall 24 to pull away from front sidewall 22. By positioning pin 60 so that a line drawn from the center of pin 60 through the center of roller 76 is perpendicular to face 75 of the latch slide knob, there will be no tendency for the locking hook to come disconnected under the strain.
The compressive strain on latch slide 62 is resisted by bracket 64 and stop bolt 70 which backs keeper washer 68. Additionally, stop bolt 70 secures one end of U-shaped bar 80 to the end of latch slide 62. The second end of U-shaped bar 80 has mounted therein piston rod 82 of damping cylinder 84 which is secured to sidewall 22 by bolt 86 (See FIG. 3). The purpose of damping cylinder 80 is to absorb the energy stored in spring 66 when the latch is released by drawing latching hook 58 out of engagement with the knob on the end of latch slide 62. Without damping cylinder 84, latch slide 62 would clang back on release, propelled by the stored energy in the spring 66. However, using a damping cylinder of the type used as shock absorbers for automobiles, piston 82 can easily be drawn out as spring 66 is compressed. Then, on release of the latch, piston 82 resists quick expansion of the spring.
The compression of spring 66 due to the pressure being exerted within the baling chamber causes the rearmost part of the baler to draw away from the front. The tailgate comes ajar and sidewall 24 separates from sidewall 22 as shown in FIG. 4. The amount of sidewall separation can be measured by at least two methods. One is the angularly moving arm 84 which acts against striker plate 87. When arm 84 is spring biased against striker plate 87, the arc 85 through which the arm travels can be mechanically transferred and amplified as necessary to visually inform the machine operator of the status of the bale. Alternately, an electrical type of off-on switch 88 can be used. Central plunger 90 of the switch is spring actuated to rest against striker plate 92. When sidewalls 22 and 24 separate by some predetermined amount, switch 88 is turned "on". Turning "on" of switch 88 can be used for several things. It can energize a warning light and/or a horn. Either of these will signify to the operator that the progress of the baler along the windrow should be halted and the bale discharge event completed.
It is also possible to use the sensor to automatically initiate the discharge sequence. Triggering of switch 88 could start the bale tying sequence preparatory to opening the tailgate wide for bale discharge. My mechanical bale density indicator is both simple and reliable. Its availability eliminates the hydraulically instrumented pressure sensors used in the prior art balers.
While the invention has been described in conjunction with a baler which produces large round bales, it will be understood that it can be of equal utility in other embodiments. Various changes in the details, materials, steps and arrangement of parts may be made and will occur to those skilled in the art upon a reading of the above disclosure. Therefore, the invention should not be limited to the specific illustration disclosed, but only by the following claims.
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A latch mechanism is presented which is useful with a machine which gathers crop material from a windrow and forms it into large round bales. The latching mechanism senses bale density while holding the opposing faces of the tailgate closed during the bale forming operation. Density is sensed by spring mounting the latch slides so that the tailgate comes slightly ajar when pressure in the baling chamber builds up. The amount of separation of the opposing faces of the tailgate is sensed and when it exceeds a specified amount, initiates a bale discharge sequence. The tailgate lifting mechanism is interlocked with the latch release to assure safe operation of the system.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for the production of N-vinyl-2-pyrrolidone by gas-phase dehydration reaction at atmospheric pressure, in particular to a method for producing N-vinyl-2-pyrrolidone by dehydrating N-(β-hydroxyethyl)-2-pyrrolidone employing a mixed oxide of group IV elements as catalyst at a temperature of 300°-450° C. and at a space velocity of 500-4500 hr -1 .
2. Description of the Prior Art
N-vinyl-2-pyrrolidone is a valuable and useful fine chemical. Due to its unique physical properties such as water solubility, high polarity, nontoxicity, chemical stability and cation activity, it has been widely applied in the manufacture of adhesives, paints, textiles, foods and personal medicines. The homopolymers or copolymers thereof have improved film strength, dye compatibility, rigidity and adhesion.
Conventionally, N-vinyl-2-pyrrolidone is produced by utilizing the "Reppe Reaction" to subject 2-pyrrolidone and acetylene to vinylation. However, there are various difficulties with the acetylene employing Reppe Reaction. Moreover, acetylene is easy to explode, and is thus difficult to transport and handle. Consequently, alternative methods have been proposed. Among them, process employing N-(β-hydroxyethyl)-2-pyrrolidone as raw materials is deemed as most desirable process. For example, in U.S. Pat. No. 2,775,599 issued to Puetzer et al, it is disclosed that N-vinyl-2-pyrrolidone is obtained by reacting N-(β-hydroxyethyl)-2-pyrrolidone with thionyl chloride to form N-β-chloroethyl-2-pyrrolidone, followed by removing hydrogen chloride. Also, U.S.S.R. Patent No. 125,567 discloses a method which involves reacting N-(β-hydroxyethyl)-2-pyrrolidone with acetic anhydride to form ester, followed by removing acetic anhydride to obtain N-vinyl-2-pyrrolidone. Methods for producing N-vinylpyrrolidone by directly dehydrating N-(β-hydroxyethyl)-2-pyrrolidone without the formation of intermediates are disclosed in, for example U.S. Pat. No. 2,669,570. According to the production method of said patent, the dehydration reaction is carried out by directly contacting N-(β-hydroxyethyl)-2-pyrrolidone with dehydration catalysts at a temperature of 300°-340° C., and under sub-atmosphereic pressures below 100 mm of mercury at a hourly vapor space velocity of 500-4000 hr -1 . The employed dehydration catalysts are active aluminum, calcium oxide-aluminum or iron oxide-potassium hydroxide. By using active aluminum, N-vinyl-2-pyrrolidone is produced by yields above 64 mole %. The catalytic dehydration process, however, should be carried out at a reduced pressure below 100 mm of mercury, and thus is not practical for industrial production.
U.S. Pat. No. 3,821,245 discloses a method for producing N-vinyl-2-pyrrolidone by dehydrating N-(β-hydroxyethyl)-2-pyrrolidone employing an oxide selected from zirconium oxide, thorium oxide, cerium oxide, zinc oxide and chromium oxide as a catalyst. The yield of the method is improved and the reaction can be conducted at atmospheric pressure. Among these oxides, zirconium oxide has the best catalytic activity, and when the reaction is carried out at 350° C. at a space velocity of 1800 hr -1 for 2.5 hours, the conversion of N-(β-hydroxyethyl)-2-pyrrolidone can reach 95.7 mole %. However, disadvantages of the method are that the selectivity of N-vinyl-2-pyrrolidone is not high, merely 73.8 mole %, and its catalyst life is short. When the reaction proceeds for 50 hours, the conversion rapidly drops to 80 mole %, and thus the method is not suitable for industrial production.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for the production of N-vinyl-2-pyrrolidone by which method, the yield is improved, the catalyst life is lengthened, and the dehydration reaction can be conducted at atmospheric pressure.
The object of the invention is attained by employing a mixed oxide of group IV elements as catalysts.
Specifically, the method of the invention includes dehydrating N-(β-hydroxyethyl)-2-pyrrolidone in the presence of a mixed oxide of group IV elements at a temperature of 300°-450° C., at a space velocity of 500-4500 hr -1 . The mixed oxide is a mixture of at lease two oxides of group IV elements, and the oxides are selected from zirconium oxide, tin oxide, titanium oxide, silicon oxide and hafnium oxide. The oxides can be modified with alkali metal or alkaline earth metal oxides.
According to an aspect of the present invention, the dehydration reaction can be carried out at atmospheric pressure and the yield of N-vinyl-2-pyrrolidone can reach 84 mole %. The by-product of the dehydration reaction is valuable 2-pyrrolidones, and thus the total yield can be higher than 95 mole %.
According to another aspect of the present invention, the surface of the mixed oxide catalysts of the present invention contains both active acid and base sites. The acidity and basicity of the acid sites and basic sites are moderate, and thus are especially suitable for the catalytic dehydration of N-(β-hydroxyethyl)-2-pyrrolidone. And as no special strong acid sites exist on the surface of the catalysts, the formation of cracking products can be inhibited, and thus the catalyst life can be lengthened. Moreover, as the surface of the catalysts contains both active acid sites and basic sites, the activity of the catalysts of the present invention is rather high, and thus the selectivity of the product, N-vinyl-2-pyrrolidone exceeds 90 mole %
The present invention can be more fully understood by reading the subsequent detailed description and examples.
DETAILED DESCRIPTION OF THE INVENTION
The mixed oxides according to the present invention are mixed oxides of group IV elements. Examples of suitable oxides include zirconium oxide, tin oxide, titanium oxide, silicon oxide and halfnium oxide. The mixed oxides can be a mixture of two or at least two of the above oxides. Preferred combinations are zirconium oxide-tin oxide, zirconium oxide-titanium oxide, zirconium oxide-silicon oxide, or zirconium oxide-hafnium oxide. The content of zirconium in the above combinations is preferably 10-99 wt %, and more preferably 50-99 wt %.
The above mixed oxides can be prepared by coprecipitation. The coprecipitation method includes mixing the salts of group IV elements, such as their chlorides or nitrates, in a suitable solvent such as water or alcohol, adjusting the pH value of the resulting solution to 8-11 to form hydroxide precipitate, and then filtering, washing, drying and calcining the hydroxide precipitate at 300°-1000° C. for 2-12 hours to form the catalyst. The mixed oxides can also be prepared by other methods such as impregnation or kneading methods.
The mixed oxide dehydration catalysts of the present invention can be modified by impregnating them in an aqueous solution containing alkali metal elements or alkaline earth metal elements for several hours, followed by drying and calcining at 300°-1000° C. for several hours. The amount of the alkali metal elements or alkaline earth metal elements contained in the modified catalysts should be not more than 1.0 wt %.
The dehydration catalysts of the present invention can be easily regenerated. For example, introducing air or oxygen-containing gases or steam and treating at 400°-700° C. for 2-5 hours can recover the activity of the catalysts.
The catalytic dehydration reaction is preferably carried out at 250°-500° C., more preferably at 300°-450° C. If the dehydration reaction is carried out at a temperature below 250° C., the conversion is rather low and thus is not practical, and if the reaction is carried out at a temperature above 500° C., the cracking products increase. The dehydration reaction can be carried out at atmospheric pressure, reduced pressure or at a pressure higher than atmospheric pressure. The gaseous space velocity (GHSV) of the feed, according to the present invention, is about 500-4500 hr -1 , preferably 900-3600 hr -1 . The N-(β-hydroxyethyl)-2-pyrrolidone can be fed after it is gasified or be fed by a mixed feed method after it is diluted with inert gases such as nitrogen gas.
As aforesaid, the by-product of the catalytic dehydration reaction of the present invention is 2-pyrrolidone which is a valuable substance. The by-product can be easily separated from the product, N-vinyl-2-pyrrolidone, for example, by reduced pressure distillation. Also, according to the method of the invention, the selectivity of N-vinyl-2-pyrrolidone is rather high, usually above 90 mole %.
The examples which follow illustrate the method according to the present invention without implying any limitations. In these examples, the dehydration reaction is carried out in a fixed bed reactor at atmospheric pressure. The fixed bed reactor is a 3/8 inch diameter, 60 cm long stainless tube in which the catalyst bed is 5-10 cm in height. The outside preheating zone is controlled at 300° C., and the reaction temperature is controlled at 300°-400° C. The reactant N-(β-hydroxyethyl)-2-pyrrolidone is pumped to the top of the tube reactor, mixing with nitrogen gas at a 1:1 molar ratio and then introduced into the reactor. The gasous space velocity is maintained at 500-4500 hr -1 . The products are collected after condensation, and a portion of the collected products is used to quantify the compositions of the products by a HP 5890 gas chromatograph using HP-FFAP (0.53×30 m capillary column) as separation column and FID detector.
Conversion, yield and selectivity are calculated respectively by the following equations (1), (2) and (3). ##EQU1##
EXAMPLE 1
214 g of zirconium oxychloride (ZrOCl 2 •8H 2 O) and 19 g of titanium chloride (TiCl 4 ) were respectively dissolved in anhydrous ethanol, and the resulting solutions were mixed homogeneously. Ammonia water was dropped into the resulting mixture. The addition of ammonia water was stopped when the pH value of the solution reached 10. A viscous mixture was formed, and the viscous mixture was thereafter filtered, washed, and dried. The dried mixture was then calcined at 550° C. for 4 hours, compressed and grounded into 30-50 mesh.
3 ml of the grounded catalyst was placed in a stainless tube reactor as mentioned above. The preheated zone was maintained at a temperature of 300° C., and the reaction zone was maintained at 370° C. N-(β-Hydroxyethyl)-2-pyrrolidone was supplied to the reaction tube at a rate of 10 g/hr together with nitrogen gas as carrier (at 30 cc/min), whereby a total space velocity of 3600 hr -1 was obtained. Liquid products obtained during a reaction period from 2.0 to 2.5 hours were collected and quantified by Gas Chromatography. As a result, it was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 91.0 mole %, the selectivity of N-vinyl-2-pyrrolidone was 76.3 mole % and the selectivity of 2-pyrrolidone was 21.6 mole %.
EXAMPLE 2
296 g of zirconium oxychloride (ZrOCl 2 •8H 2 O) and 26 g of tin chloride (SnCl 4 ) were respectively dissolved in anhydrous ethanol, and the resulting solutions were mixed homogeneously. Ammonia water was dropped into the resulting mixture. The addition of ammonia water was stopped when the pH value of the solution reached 9. A viscous mixture was formed, and the viscous mixture was thereafter filtered, washed, and dried. The dried mixture was then calcined at 500° C. for 4 hours, compressed and grounded into 30-50 mesh.
3 ml of the grounded catalyst was placed in a stainless tube reactor as mentioned above. The preheated zone was maintained at a temperature of 300° C., and the reaction zone was maintained at 360° C. N-(β-Hydroxyethyl)-2-pyrrolidone was supplied to the reaction tube at a rate of 10 g/hr together with nitrogen gas as carrier (at 30 cc/min), whereby a total space velocity of 3600 hr -1 was obtained. Liquid products obtained during a reaction period from 2.0 to 2.5 hours were collected and quantified by Gas Chromatography. As a result, it was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 99.2 mole %, the selectivity of N-vinyl-2-pyrrolidone was 88.7 mole % and the selectivity of 2-pyrrolidone was 10.7 mole %.
EXAMPLE 3
A catalyst as prepared as specified in Example 2 was employed, and the reaction was conducted under similar conditions except that the reaction temperature was 330° C. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 84.0 mole %, the selectivity of N-vinyl-2-pyrrolidone was 97.1 mole % and the selectivity of 2-pyrrolidone was 2.9 mole %.
COMPARATIVE EXAMPLE 1
214 g of zirconium oxychloride was dissolved in anhydrous ethanol, and ammonia water was dropped into the resulting solution. The addition of ammonia water was stopped when the pH value of the solution reached 10. Thereafter, catalyst was prepared and dehydration reaction was conducted as described in Example 3. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 42.1 mole %, the selectivity of N-vinyl-2-pyrrolidone was 89.1 mole % and the selectivity of 2-pyrrolidone was 4.2 mole %.
EXAMPLE 4
In this example, a catalyst was prepared as described in Example 2 but calcined at 900° C., and the dehydration reaction was conducted under similar conditions except that the reaction temperature was 370° C. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 83.4 mole %, the selectivity of N-vinyl-2-pyrrolidone was 94.0 mole % and the selectivity of 2-pyrrolidone was 6.0 mole %.
COMPARATIVE EXAMPLE 2
In this comparative example, a catalyst prepared as described in comparative Example 1 was employed, and the reaction was conducted under similar conditions except that the reaction temperature was 370° C. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 99.5 mole %, the selectivity of N-vinyl-2-pyrrolidone was 65.9 mole % and the selectivity of 2-pyrrolidone was 32.9 mole %.
EXAMPLE 5
50 g of Sn--Zr catalyst, which was prepared by a method similar to that set forth in Example 2, was then modified by being impregnation in a 200 ml, 0.001 g potassium hydroxide containing aqueous solution, and then calcined. Dehydration reaction was then conducted under similar conditions by using the obtained catalyst. The conversion of N-(β-Hydroxyethyl)-2-pyrrolidone (NHEP) and the selectivity of N-vinyl-2-pyrrolidone (NVP) are summarized in Table 1.
EXAMPLE 6
In this example, a Sn--Zr catalyst was prepared as described in Example 5 but a 200 ml, 0.5 g calcium hydroxide containing aqueous solution was used to modify the catalyst. The same reaction conditions as in Example 5 were used. The results thus obtained are summarized in Table 1.
TABLE 1__________________________________________________________________________ catalyst calcination reaction NVPExample temperature temperature conversion selectivityNo. promoters (°C.) (°C.) (%) (%)__________________________________________________________________________5 potassium 800 360 96.8 92.1 hydroxide6 calcium 500 360 96.4 94.3 hydroxide__________________________________________________________________________
EXAMPLE 7
In this example, a catalyst was prepared as described in Example 1 but ethylene glycol was used as solvent, and the calcination temperature was 600° C. The dehydration reaction was also conducted under similar conditions except that the reaction temperature was 350° C. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 93.9 mole %, the selectivity of N-vinyl-2-pyrrolidone was 88.7 mole %.
EXAMPLE 8
In this example, a catalyst was prepared as described in Example 2 and the dehydration reaction was conducted under similar conditions except that the reaction temperature was 330° C. and the total space velocity was 900hr -1 . It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 96.3 mole %, the selectivity of N-vinyl-2-pyrrolidone was 87.2 mole %.
COMPARATIVE EXAMPLE 3
In this comparative Example 3, the same catalyst as Comparative Example 1 and the reaction conditions as set forth in Example 8 were used. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 52.4 mole %, the selectivity of N-vinyl-2-pyrrolidone was 84.1 mole %.
EXAMPLE 9
In this example, the same catalyst composition as Example 2 was used, but water was used as solvent, and the calcination temperate was 500° C. and the reaction temperature was 350° C. It was found that the conversion of the N-(β-Hydroxyethyl)-2-pyrrolidone was 94.4 mole %, the selectivity of N-vinyl-2-pyrrolidone was 90.9 mole %.
EXAMPLE 10
In this example, the same catalyst preparation method and reaction as Comparative Example 2 were used except that 50 g of the resulting ZrO 2 catalyst was first impregnated in a 200 ml, 0.001 g potassium hydroxide containing aqueous solution for modification and then subjected to calcin before it was used for dehydration reaction. The results are summarized in Table 2.
EXAMPLE 11
The same catalyst preparation method and reaction as Example 10 were used except that the catalyst was impregnated in a 200 ml, 0.5 g calcium hydroxide containing aqueous solution before it was used for dehydration reaction. The results are also summarized in Table 2.
TABLE 2__________________________________________________________________________ catalyst calcination reaction NVPExample temperature temperature conversion selectivityNo. promoters (°C.) (°C.) (%) (%)__________________________________________________________________________10 potassium 800 370 98.9 81.8 hydroxide11 calcium 500 370 97.8 85.8 hydroxide__________________________________________________________________________
EXAMPLE 11
Catalyst produced in a manner similar to that in Example 2 was employed and the dehydration reaction of N-(β-Hydroxyethyl)-2-pyrrolidone was continued for 100 hours under similar conditions to test the catalyst life. The results thus obtained are summarized in Table 3. It is seen from Table 3 that the yield is very high, the catalyst life is long and the conversion of N-(β-Hydroxyethyl)-2-pyrrolidone is still higher than 80 mole % even the reaction has proceeded for 100 hours.
TABLE 3______________________________________ time from start of reaction (hr) 10 20 30 40 50 70 100______________________________________NHEP conversion 99.6 96.8 97.2 92.3 91.8 83.2 82.8(mole %)NVP selectivity 78.9 91.3 90.2 94.6 94.6 97.1 97.2(mole %)2-P selectivity 20.0 8.2 8.7 4.9 4.7 2.9 2.8(mole %)______________________________________
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The present invention relates to a method for the production of N-vinyl-2-pyrrolidone by gas-phase reaction at atmospheric pressure. The method is characterized in that a gas-phase reaction is conducted by using N-β-Hydroxyethyl-2-Pyrrolidones serving as raw materials, at a temperature of 300°-450° C., a space velocity of 500-4500 hr -1 in the presence of a mixed oxide of group IV elements, or an oxide of group IV elements, which has been modified by group I or group II elements.
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FIELD OF THE INVENTION
[0001] The present invention relates to baby feeding containers in general, and to a container for feeding premature babies in particular.
BACKGROUND OF THE INVENTION
[0002] Premature babies or preemies are human children that are born after less than 37 weeks of pregnancy, which is more than three weeks before their due date. Premature birth gives the baby less time to develop in the womb, and as a result a preemie's body is often vulnerable, weak, and low in weight. Premature babies, especially those born very early, often have complicated medical problems and require neonatal intensive care. Providing neonatal intensive care to preemies can be a difficult and stressful task for the medical staff charged with providing the care, the families of the babies, and the preemies themselves. The length of stay for a preemie in the Neonatal Intensive Care Unit (NICU) in a Hospital can last a relatively long time, until the preemie's physical condition is strong and stable enough for him to be discharged.
[0003] One of the critical and frequent occurrences for a preemie in the NICU is feeding time. Breast feeding requires a relatively large amount of physical strength and effort on the part of the preemie, and can be a complex process for a preemie due to his size and capabilities. Accordingly, breast milk, which is favored by doctors, cannot be naturally fed directly from the mother's breast. Instead, breast milk is transmitted from the mother's breast to the preemie using several containers, tools and vessels. Typically a mother will express milk using a pump into a vessel. The milk is then transferred from that vessel into a storage container that is marked and placed in cold storage. During feeding time the storage container is removed from storage and a syringe is used to measure an amount of milk to be fed to the preemie. This milk is then transferred to a bottle and fed to the preemie. Since it is critical for the preemie to feed properly, any milk that remains in the bottle after bottle feeding is given to the preemie directly. The milk is therefore transferred, once again, this time from the bottle to a feed-tube that inputs the milk into the preemie's stomach. Each time the milk is transferred to a different container complicates the feeding process, and more importantly exposes it to possible contamination and loss of nutritional value.
SUMMARY OF THE INVENTION
[0004] In accordance with one aspect of the present invention, there is thus provided a baby feeding kit, wherein the kit is operational in syringe mode, storage mode, feed-bottle mode, and feed-tube mode. The kit includes a container body configured for holding a liquid. The container body includes a tube portion defining a cavity therein, a wide opening disposed at one end of the tube portion, and a narrow opening disposed at an opposite end of the tube portion. The kit further includes a plunger sized to removably and sealingly fit inside the cavity and slidably move there along when the container is in a syringe mode, and to seal the tube portion when the container is in a storage mode. The kit further includes an attachable nipple operational for sealingly attaching to the wide opening, configured for releasing a liquid held in the container body when sucked on when the container is in a feed-bottle mode in which the plunger is removed, and for pressurizing fluids when the container is in a feed-tube mode, and which is removed when the container is in a syringe or storage mode. The kit further includes an attachable cap operational for sealingly attaching to the narrow opening, and is configured to seal the narrow opening of the container when in storage or in feed-bottle mode. The kit further includes a feeding tube operational for sealingly attaching to the narrow opening, and is configured for releasing a liquid held in the container body when the container is in a feed-tube mode.
[0005] In accordance with another aspect of the present invention, at least one of the wide opening and the narrow opening includes an attachment element that corresponds to a complementary attaching element disposed on at least one of: the nipple, the cap, and the feeding tube for attaching thereto.
[0006] In accordance with another aspect of the present invention the attachment element and the complementary attachment element are screw threads.
[0007] In accordance with another aspect of the present invention the kit further includes a gripping sleeve configured to slide externally onto and off of the container body, and to provide a grip support facilitating holding of the container body in the feed bottle mode and optionally having an securing element, such as a clip, for securing the gripping sleeve to an object.
[0008] The baby feeding kit of claim 4 , further comprising a carrier for removably storing and carrying the gripping sleeve. The carrier can include a handle for providing a hanging suspension for the gripping sleeve, and a hanger for hanging the carrier.
[0009] In accordance with another aspect of the present invention the kit further includes a carrier, wherein
[0010] the gripping sleeve is configured to be removably stored inside the carrier.
[0011] In accordance with another aspect of the present invention the kit is operational in a pump vessel mode. The wide opening is configured for attaching to a breast pump, which can be part of the kit, for pumping milk from a breast into the container body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:
[0013] FIG. 1 is an exploded plan view of a container, constructed and operative in accordance with an embodiment of the present invention;
[0014] FIG. 2 is a perspective view of the container of FIG. 1 in a syringe mode;
[0015] FIG. 3 is a perspective view of the container of FIG. 1 in a storage container mode;
[0016] FIG. 4 is a perspective view of the container of FIG. 1 in a feed-bottle mode;
[0017] FIG. 5 is a perspective view of the container of FIG. 1 in a feed-tube mode;
[0018] FIG. 6 is a perspective view of the sleeve and carrier of FIG. 1 ;
[0019] FIG. 7 is a perspective view of the container of FIG. 1 in a feed-tube mode and being held by the sleeve and carrier; and
[0020] FIG. 8 is a perspective view of the container of FIG. 1 in a pump vessel mode.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The present invention overcomes the disadvantages of the prior art by providing a kit with a container that simplifies the feeding process for preemies. The container can be adapted for use as a syringe, storage container, feed-bottle or feeding tube. Optionally, the container can be used as a pump vessel, connecting directly to a breast pump. The container can be used as a syringe to measure the exact amount of milk given to the preemie, a critical step in the feeding process for preemies that need to feed properly to develop properly. The term “milk” herein refers to any liquid, including artificial substitutes, water, medical preparations, and the like, which is intended for feeding. The container can be sealed for further storage. The container is readily adapted for use as a feed-bottle which allows a parent or caregiver to feed the preemie without having to transfer the milk. Additionally, the container can be adapted for use as a feeding tube to input the milk into the stomach of the preemie. The milk remains in the container from its filling (syringe phase or as a pump vessel) until its consumption by any of the modes (syringe, storage, feed-bottle, feeding tube), without requiring its transfer into further vessels.
[0022] Reference is now made to FIG. 1 , which is an exploded plan view of a container kit 100 , constructed and operative in accordance with an embodiment of the present invention. The invention present concerns a kit, however, add-on elements may be utilized in conjunction with existing elements to receive the kit. Accordingly reference herein below to “container 100 ” is made for convenience purposes and is synonymous to “kit 100 ”. Container 100 includes a body 102 , a plunger 104 , a nipple 106 , a cap 108 , a feeding tube 110 , an optional gripping sleeve 501 , and an optional carrier 601 . Feeding tube 110 incorporates an adapter portion (designated 110 for the sake of simplicity) as in FIGS. 1, 5 and 7 , while a tube portion 510 appears hanging therefrom in FIG. 5 .
[0023] Body 102 includes a tube portion 103 featuring an interior cavity 116 for holding a liquid. At one end of tube portion 103 , body 102 includes a wide opening 111 with external screw threads 112 . At the opposite end of tube portion 103 , body 102 includes a narrow opening 113 with external screw threads 114 . Narrow opening 113 has a diameter which is smaller than the diameter of tube portion 103 , and wide opening 111 has a diameter substantially equal to or greater than the diameter of tube portion 103 . Body 102 also includes a scale mark or graduation mark 130 printed or etched onto container 100 for measuring an amount of liquid inside container 100 . Scale 130 is written in a direction that makes it easy to read while narrow opening 113 is pointed downwards and wide opening 111 is pointed upwards as is further demonstrated in FIGS. 2, 5, and 7 . A second scale mark or graduation mark 132 is printed or etched onto container 100 in the opposite direction of scale 130 , so that it is easy to read while wide opening 111 is pointed downwards and narrow opening 113 is pointed upwards, as in FIG. 4 . Plunger 104 is sized so that it can sealingly and slidably fit inside cavity 116 of body 102 , wherein a seal 105 of plunger 104 is fitted to slide along the internal walls of tube portion 103 . Plunger 104 can be inserted into tube portion 103 through wide opening 111 with its seal 105 proximate to narrow opening 113 , allowing the sucking up of liquid through narrow opening 113 , as a typical syringe is operated. Nipple 106 includes internal screw threads 118 that correspond to external screw threads 112 on body 102 . Cap 108 and feeding tube 110 each include internal screw threads 120 and 122 . respectively, that correspond to external screw threads 114 on body 102 . In place of corresponding screw threads 112 , 114 , 118 , 120 and 122 other corresponding complementary attachment elements, arrangements or configurations may be provided on the respective parts of container 100 , such as corresponding snap fit or mounting rail and track elements. Optional gripping sleeve 501 has two open ends and is configured to selectively embrace container 100 by sliding externally onto and off of body 102 of container 100 . Gripping sleeve 501 has widened external dimensions configured to facilitate holding of container body 102 in feed bottle mode 400 . Gripping sleeve 501 has an optional clip 502 or other securing element, for securing to an object, such as an article of clothing of the feeder (mother or nurse), or hanging by further means, such as those described below with reference to carrier 601 and to FIG. 6 , which is a perspective view of the sleeve and carrier of FIG. 1 . Carrier 601 is a case or a box configured to open and close and has an interior fitted to encapsulate gripping sleeve 501 . Carrier 601 may be opened to allow Gripping sleeve 501 to be placed inside and then closed again to store Gripping sleeve 501 inside (see FIG. 6 ). Carrier 601 also has a handle 602 and a hanger 604 . Handle 602 is configured to be attached to clip 502 of gripping sleeve 501 and provide hanging suspension thereto (see FIG. 7 ). Hanger 604 is configured to be hung on an object, such as a hook or a suspension rack (which are often already nearby) (see FIG. 7 ). Carrier 601 may be opened to remove gripping sleeve 501 and then closed again to be attached to gripping sleeve 501 , using the clip 502 and handle 602 , and used to help hang container 100 from an object, such as a piece of medical or other structural equipment, hook or suspension rack (see FIGS. 6 and 7 ).
[0024] An optional breast pump 802 (see FIG. 8 ) with internal screw threads 804 that correspond to external screw threads 112 on body 102 may be provided. Breast pump 802 is configured for pumping milk from a breast into the container body 102 , as a typical breast pump is operated. Breast pump 802 may be provided together with container 100 as part of the kit, or it may be any breast pump that container 100 is configured to attach to.
[0025] Container 100 has a plurality of modes or configurations: a syringe mode, a storage mode, a feed-bottle mode, a feed-tube mode, and optionally a pump vessel mode.
[0026] Reference is now made to FIG. 2 , which is a perspective view of the container 100 of FIG. 1 , in a syringe mode 200 , constructed and operative in accordance with an embodiment of the present invention. In syringe mode 200 , plunger 104 is sealingly and slidably located in cavity 116 of tube portion 103 of body 102 , so that it seals one end of container 100 adjacent wide opening 111 and is capable of creating a vacuum in cavity 116 when pulled towards that end. In syringe mode 200 container 100 is capable of sucking up a liquid by inserting narrow opening 113 of the container 100 in a liquid and pulling out plunger 104 (pulling plunger 104 away from narrow opening 113 and towards wide opening 111 ). Syringe mode 200 also provides for application of the milk contained in body 102 through narrow opening 113 , by pushing plunger 104 , for direct feeding of the baby (or for a further vessel if a simple syringe functioning of the multi-functional kit 100 satisfies the user).
[0027] Reference is now made to FIG. 3 , which is a perspective view of the container 100 of FIG. 1 , in a storage mode 300 , constructed and operative in accordance with an embodiment of the present invention. Plunger 104 remains inserted (perforated line denotes the position of plunger seal 105 ) and the narrow opening 113 is sealed by cap 108 thereby sealingly enclosing tube portion 103 so that liquid contained therein (within enclosed cavity 116 ) can be safely stored. An optional plastic bag wrapper 302 with an ID or quick response (OR) barcode can be used to help store and identify container 100 .
[0028] FIG. 4 is a perspective view of the container 100 of FIG. 1 in a feed-bottle mode 400 , constructed and operative in accordance with an embodiment of the present invention. In feed-bottle mode 400 nipple 106 is connected to body 102 at wide opening 111 using corresponding screw threads 112 and 118 . Cap 108 is connected to body 102 at narrow opening 113 using corresponding screw threads 120 and 114 . In feed-bottle mode 400 , container 100 is closed at both ends 111 and 113 so that a liquid in container 100 is released only by sucking on nipple 106 when nipple 106 is used for feeding (nipple 106 is pointed downwards directly or at an angled posture so that liquid that settles downwards can pour from nipple 106 ). Optional gripping sleeve 501 is slid externally around tube portion 103 of container 100 allowing comfortable gripping in a feeding posture. Clip 502 can be used to hold container 100 in an upright manner (with nipple 106 facing upwards) when attached to an article of clothing (such as a shirt collar) in between bottle feedings. This makes container 100 easy to carry from place to place, and helps prevents a user from misplacing container 100 .
[0029] Reference is now made to FIGS. 5 and 7 . FIG. 5 is a perspective view of the container 100 of FIG. 1 in a feed-tube mode 500 , constructed and operative in accordance with an embodiment of the present invention. FIG. 7 is a perspective view of the container of FIG. 1 in a feed-tube mode and being held by the sleeve and carrier. In feed-tube mode 500 nipple 106 is connected to body 102 at wide opening 111 using corresponding screw threads 112 and 118 . Feeding tube 110 is connected to body 102 at narrow opening 113 using corresponding screw threads 122 and 114 . Tube portion 510 of feeding tube 100 hangs therefrom towards the fed infant. In feed-tube mode 500 container 100 is capable of expressing a liquid through feeding tube 110 by pumping or depressing nipple 106 (pushing nipple 106 towards narrow opening 113 ). Optional gripping sleeve 501 is preferably slid externally around tube portion 103 of container 100 so that clip 502 can be attached to any hook or rack, or to handle 602 of carrier 601 and used to hold container 100 in an upright manner (with nipple 106 facing upwards) when attached to a piece of structural equipment using hanger 604 , especially during tube feedings, as best seen in FIG. 7 . Hanger 604 makes container 100 easy to hang from a corresponding hook ( FIG. 7 ).
[0030] Reference is now made to FIG. 8 , which is a perspective view of the container 100 of FIG. 1 , in a pump vessel mode 800 , constructed and operative in accordance with an embodiment of the present invention. In pump vessel mode 800 a breast pump 802 is connected to body 102 at wide opening 111 using corresponding screw threads 112 and 804 . Cap 108 is connected to body 102 at narrow opening 113 using corresponding screw threads 120 and 114 . In pump vessel mode 800 milk may be pumped from a breast directly into the container body 102 , thereby eliminating the transfer of milk from another vessel.
[0031] The operation of container 100 will now be further discussed. Reference is now made to FIGS. 1 to 5, and 8 . After milk has been expressed or pumped by a mother into an external vessel (not sho n container 100 is assembled or configured into syringe mode 200 by placing plunger 104 into body 102 and used to suck up and measure an amount of milk for feeding to the baby by inserting narrow opening 113 into the milk and pulling plunger 104 towards wide opening 111 ( FIG. 2 ). Container 100 is now converted into storage mode 300 by connecting cap 108 over narrow opening 113 and used to store the milk until feeding time ( FIG. 3 ). If no storage is required, container 100 can also be converted from syringe mode 200 directly into feed-bottle mode 400 , or feed-tube mode 500 , as desired. When it is feeding time, container 100 is then converted, either from syringe mode 200 or storage mode 300 , into feed-bottle mode 400 by pulling plunger 104 through wide opening 111 until its entire removal from body 102 and connecting nipple 106 over wide opening 111 ( FIG. 4 ). Optionally, gripping sleeve 501 is sled over container 100 to an embracing position there over, providing a comfortable grip for a feed-bottle posture ( FIG. 4 ) or a clasp. After feeding milk to the baby using feed-bottle mode 400 , if any milk remains to be fed to the baby, or in case the baby could not be fed by using feed-bottle mode, the container 100 is converted into feed-tube mode 500 by removing cap 108 and replacing it with feeding tube 110 ( FIGS. 5 and 8 ). Optionally, gripping sleeve 501 is slid over container 100 to an embracing position there over, providing a clip 502 for temporary clipping or hanging of container 100 in between continuous feeding sessions. Feed-tube mode 500 can be also selected directly after milk is inserted into container 100 at the syringe mode 200 or at the pump vessel mode 800 . In feed-tube mode 500 , pumping or depressing nipple 106 (or pushing nipple 106 towards narrow opening 113 ) will pressurize air and liquids enclosed within cavity 116 and cause milk in body 102 to be expressed from the container 100 through feeding tube 110 .
[0032] Alternatively, container 100 may initially be configured in pump vessel mode 800 by connecting breast pump 802 over wide opening 111 and cap 108 over narrow opening 113 and used to pump milk from a breast into the container bodyl 02 by placing breast pump 802 on a breast. Container 100 can then be converted from pump vessel mode 800 into any of the other modes (e.g., storage mode 300 , feed-bottle mode 400 , or feed-tube mode 500 ) as desired, in the manner described in detail above.
[0033] The container of the present invention simplifies the process of feeding a preemie by reducing the number of vessels through which the milk is transferred before it is delivered to the baby. This reduction in amount of transfers helps preserve the quality of the milk and its essential components by reducing the milk's exposure to possible infection or contamination, and reducing the amount of milk and milk components loss due to transfer between vessels.
[0034] The various elements of the container may be provided as a baby feeding kit.
[0035] While certain embodiments of the disclosed subject matter have been described, so as to enable one of skill in the art to practice the present invention, the preceding description is intended to be exemplary only. It should not be used to limit the scope of the disclosed subject matter, which should be determined by reference to the following claims.
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A baby feeding kit operational in syringe mode, storage mode, feed-bottle mode, and feed-tube mode. The kit includes a container body, a plunger, an attachable nipple, an attachable cap and a feeding tube.
The container body includes a tube portion defining a cavity for holding a liquid having therein, a wide opening disposed at one end and a narrow opening disposed at an opposite end. The plunger removably and sealingly fits inside the cavity and slidably move there along when the container is in a syringe mode, and seals the tube portion when the container is in a storage mode. The attachable nipple sealingly attaches to the wide opening for releasing a liquid held in the container body when sucked on when the container is in a feed-bottle mode in which the plunger is removed, and for pressurizing fluids when the container is in a feed-tube mode, and is removed when the container is in a syringe or storage mode. The attachable cap seals the narrow opening of the container when in storage or in feed-bottle mode. The feeding tube sealingly attaches to the narrow opening for releasing a liquid held in the container body when the container is in a feed-tube mode.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is concerned with a process for the oxidative bleaching of wood pulp and for deinking waste paper with the help of hydrogen peroxide in the presence of a stabilising agent.
2. Description of Related Art
For the production of paper, besides the use of native wood pulps, to an increasing extent resource is had to recycled waste paper. The reuse of waste paper as a raw material source for the production of papers with a high degree of whiteness or brightness can only take place when, on the one hand (i), the coloured materials contained in the waste paper are substantially removed by rinsing out (in the following called deinking) and, on the other hand, (ii) the residues of coloured material are subjected to a chemical bleaching. Both procedures (i) and (ii) can be carried out in a common or in a multi-step process. The bleaching chemicals are used in order to destroy the chromophores present in the fibre materials, i.e. the coloured materials originating from the waste paper, as well as the dissolved and undissolved components of the printing colours. The bleaching can be carried out with oxidising and/or reducing chemicals. Many processes for deinking and bleaching are described in the literature. A preferred process is the simultaneous deinking and bleaching with hydrogen peroxide for waste paper and wood pulp.
The combined process is carried out, for example, with an agent of the following base composition:
______________________________________sodium hydroxide 1.0-1.5% referred to atro materialhydrogen peroxide 0.5-1.5% referred to atro materialsodium silicate up to 4.0% referred to atro materialcomplexing agent 0.1-0.4% referred to atro materialsoap 0.6-1.0% referred to atro materialwaste paper/ 0.9-2.0% referred to atro material.wood pulp______________________________________
By "atro material" is to be understood the amount of the air-dried mixture of waste paper and wood pulp. The statements of percentage are percentages by weight.
In practice, as carrier medium there is essentially reused in a cyclic process the water originating from the process. The deinking process water has, in general, a temperature of 30° to 60° C. In the first step of removing the coloured material, the pH reaches a value of 9.5-10.5.
The separation of fibres and printing colours is promoted by the alkaline medium. Hydrogen peroxide has proved to be an ideal bleaching agent since it bleaches especially effectively in an alkaline medium by activation of the hydroperoxide anion (see equation 1). HO 2 - is the important molecule for the bleaching action. ##STR2##
During the process, as side reactions according to the following equation 2, there occurs a spontaneous dissociation of the hydrogen peroxide in the case of the presence of heavy metal ions or in the case of the presence of the enzyme catalase, as well as decomposition of the peroxide catalysed by peroxidases. They reduce the degree of utilisation of the amount of hydrogen peroxide used and thereby influence the bleaching action. The result is an increased requirement of hydrogen peroxide and aqueous sodium hydroxide solution.
Equation 2:
2H.sub.2 O.sub.2 →2H.sub.2 O+O.sub.2
It is known to mask the damaging action of heavy metal ions by the addition of complex formers, such as ethylenediamine-tetraacetic acid, penteric acid (DTPA), polycarboxylic acids, for example citric acid, gluconic acid, polyacrylic acid, phosphonic acids and the like. These also serve simultaneously as flotation agents in the case of deinking (cf. DE 42 04 915 Al).
As natural products, waste paper and wood pulp are nutrient media for microbiological growth. Almost all micro-organisms which occur as a natural contamination on and in waste paper and wood pulp synthesise, as cell-inherent enzymes, catalases and various peroxidases.
Micro-organisms are introduced into the deinking system by the introduction of the raw materials (waste paper and wood pulp) and by the process water. The addition of hydrogen peroxide and of other chemicals, the extreme change of the pH value and the varying temperatures during the process act as stress factors on the bacteria which can lead to lysis of the bacteria. Within the process water circulation, an equilibrium is adjusted between the rate of reproduction of the micro-organisms in the system, including the bacteria introduced by the introduced material and the lysing bacteria in the system. By means of the lysis of the bacteria, the enzyme-containing cell substance, which contains catalases and peroxidases, are given off into the deinking process water.
The influence of the enzyme catalase on the bleaching activity of hydrogen peroxide in the bleaching of waste paper and wood pulp is described in the literature. Thus, G. Galland and Y. Vernac, Progr. Pap. Recycling, Vol. 2, pp. 20-30/1992, in their treatise concerning "Bleaching of recycled pulp", refer to various causes for the decomposition of peroxide during the bleaching process.
Besides traces of heavy metals, such as iron, manganese, copper and aluminium, the enzyme catalase is mentioned as the main cause of the decomposition of peroxide. Already in the case of catalase concentrations of 45 mg/liter, 60% of the hydrogen peroxide is decomposed within 10 minutes under the usual deinking bleaching conditions. The participation of catalase in the total rate of decomposition can be determined by destroying the catalase by boiling and determining the rate of decomposition of the hydrogen peroxide before and after the boiling. The difference gives the proportion of catalase.
The following methods are discussed in order to eliminate the catalase:
1. The system is to be kept free of biological activity.
2. The catalase is to be destroyed before the bleaching with:
heat treatment greater than 70° C. sodium hypochlorite, concentration 0.3%
3. acid wash (see V. Gehr et al., Das Papier, pp. 186-195/1993).
These methods are not satisfactory. To keep an open technical system free from contaminations is practically impossible since, especially with waste paper, micro-organisms are continuously introduced into the system. A heat treatment costs energy and is time-consuming and, in addition, damages the paper fibres. The addition of hypochlorite is admittedly comparatively economic but also leads to a damaging of the fibres and to additional loading of the waste paper. The acid wash requires a separate process step and a subsequent expensive neutralisation, water-loading salts thereby again being formed.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to reduce the damaging influence of the hydrogen peroxide-decomposing catalases and peroxidases and thereby to avoid the above-mentioned disadvantages.
Thus, according to the present invention, there is provided a process for the oxidative bleaching of wood pulp and for the deinking of waste paper by means of hydrogen peroxide and a stabilising agent, wherein, as stabilising agent, there is used 2-oxo-2-(4-hydroxy-phenyl)-acethydroximic acid chloride (N,4-dihydroxy-α-oxophenylethanimidoyl chloride) of the formula: ##STR3##
The stabilising agent can be used in a concentration of 0.002-2 g/kg of process water and preferably of 0.001-0.2 g/kg.
The stabilising agent can be added to the recycled process water.
The present invention also provides an agent for stabilising hydrogen peroxide-containing bleaching and deinking solutions for waste paper, wherein it contains 2-oxo-2-(4-hydroxyphenyl)-acethydroximic acid chloride (N,4-dihydroxy-α-oxophenylethanimidoyl chloride) as stabilising agent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
After the exclusion of the activity of the enzymes, by means of the use of 2-oxo-2-(4-hydroxyphenyl)-acethydroximic acid chloride (hereinafter called paraclox) or of mixtures containing this substance, the residual content of the hydrogen peroxide in the process is increased after the bleaching procedure. This can lead to a saving of considerable amounts of hydrogen peroxide while the bleaching action remains the same (whiteness, brightness) or to an increase of the degree of whiteness in the case of reduced amounts of peroxide.
The use of the stabiliser according to the present invention takes place in the bleaching deinking process, for example in the enzyme-containing inflow of the pulp water or in the pulper itself. In the case of all further bleaching processes for waste paper (after-bleaching) or wood pulp, the above-mentioned agent is added to the fibre diluting water or to the bleaching chemicals directly before the addition of the materials to be bleached.
Paraclox has previously been used in the paper industry in order to reduce the growth of slime-forming bacteria in the water circulations and in the waste water and thereby to prevent a blockage of the pipes. It is surprising that this substance is suitable for the inactivation of free catalase and/or of peroxidase itself and not only to prevent the post-formation due to the growth of the micro-organisms.
The effectiveness of the agent used according to the present invention is shown by the following Examples.
EXAMPLE 1
Measurement of the Hydrogen Peroxide-stabilising Action of Various Antibacterially-acting Molecules on the Process Water (deinking) of a Paper Factory
The catalase test depends upon the measurement of the increase of the pressure in an airtight-closed vessel after the introduction of 0.1% hydrogen peroxide. With increasing concentration of catalase in a sample, the pressure to be measured increases correspondingly. The pressure is given as an electric signal in relative units (mV). The pressure increase is measured after 10 minutes.
______________________________________ pressure inactive substance/concentration in relative units (mV)______________________________________400 ppm 2-oxo-2-(4-hydroxyphenyl)- 0.2acethydroximic acid chloride100 ppm 2-oxo-2-(4-hydroxyphenyl)- 0.5acethydroximic acid chloride10 ppm 2-oxo-2-(4-hydroxyphenyl) 4.2acethydroximic acid chloride400 ppm 2,2-dibromo-3-nitrilo- >9.0propionamide (DBNPA)400 ppm tetrakishydroxymethyl- >9.0phosphonium sulphate (THPS)400 ppm sodium monomethyldithio- 5.0carbamate (metamsodium)400 ppm monomethylammonium mono- >9.0methyl dithiocarbamate (MDTCMA)400 ppm methylene bisthiocyanate (MBT) 6.2comparison sample without additive 9.8______________________________________ (ppm = parts per million or g of substance/100 kg water)
EXAMPLE 2
Determination of the Residual Peroxide Content After the Addition of Paraclox to Different Process Water Samples (deinking)
The measurement of the residual peroxide content took place by iodometric titration.
The initial peroxide content corresponds to 100% (=0.1% hydrogen peroxide (100%)).
______________________________________ 0 min. 30 min. 60 min. 90 min. 120 min.______________________________________Process water 1 (clear filtrate) 0 sample 100% 1.8% 0% 0% 0% 10 ppm paraclox 100% 55.4% 43.1% 33.8% 26.9%100 ppm paraclox 100% 95.4% 87.7% 87.7% 86.1%Process water 2 (drum 1) 0 sample 100% 0% 0% 0% 0% 2 ppm paraclox 100% 3.6% 0% 0% 0%20 ppm paraclox 100% 62.1% 56.8% 50.8% 47%______________________________________
EXAMPLE 3
Determination of the Effect of Paraclox on the Degree of Whiteness, the Florate, the Ash and the Residual Peroxide Content
Experimental Arrangement of the Deinking Experiment in the Laboratory
Into 1 liter of water of 30° dH (tap water) are introduced:
______________________________________ stabiliser 0.2% waterglass 2.0% aqueous sodium hydroxide solution 1.0% soap 1.0% peroxide 1.5%______________________________________
and heated to 60° C.
Into the pulper (2800 r.p.m.) are introduced 50 g of atro waste paper and the chemical solution is subsequently introduced. The pulping time is 10 minutes. After ending of the brushing out time, the paper slurry is shaken out into a glass beaker, stirred up with a commercially available ultrasonic disperser and the pH value determined.
The pH value is 9.5±0.2. 100 ml are taken from the brushed out suspension and a sheet formed (degree of whiteness and brightness before the flotation).
The remaining fibre material is placed for 110 minutes in a waterbath with a temperature of 50° C. After the residence time, it is dispersed with a disperser for 1 minute at 10,000 r.p.m. The paper slurry is emptied into a flotation cell which is filled with water with a temperature of 50° C. There is thereby adjusted a material density of 0.8% (pH value 8.5). Air is introduced into the cell at a rate of 60 liters/hour and the speed of stirring is 1000 r.p.m. The flotation time is 10 minutes, foam being skimmed off manually. After the flotation is ended, acidification is carried out with sulphuric acid to pH 5 and sheets are formed.
The brightness and degree of whiteness are measured on the front and rear side and the average value determined.
Statement of the Degree of Whiteness:
R 457: reflection factor at 457 nm wavelength
Y/C: standard type of light C/1931
Process water 1 was used. The statements of percentage refer to the commercial product and the residual peroxide was determined by a titration method.
______________________________________before after residualflotation flotation flotate ash peroxide R457 Y/C R457 Y/C % % %______________________________________0 sample 50.1 54.1 60.7 66.8 22.6 47.8 15.7paraclox 50.6 53.5 60.7 66.8 24.4 43.9 49.70.08%______________________________________
In the case of values otherwise remaining the same, the residual peroxide content shows a concentration dependency in the experimental batch.
______________________________________0 sample 15.7% residual peroxideparaclox 0.02% 21.4% residual peroxideparaclox 0.04% 28.5% residual peroxideparaclox 0.08% 49.7% residual peroxide______________________________________
EXAMPLE 4
Determination of the Influence of DTPA-containing Stabiliser (heavy metal complexing) on the Rate of Decomposition of Peroxide in Comparison With the Action of Catalase-inhibiting Substances
As sample, there was used process water 3 and worked up analogously to Example 1. After the addition of 0.1% hydrogen peroxide (referred to 100% hydrogen peroxide), there was measured the pressure increase in relative pressure units (in mV) after 10 minutes. The measurement took place at ambient temperature.
______________________________________0 sample 9.8paraclox 400 ppm 0.2 (referred to process water volume)DTPS stabiliser 5.9 (referred to process water volume)2000 ppm______________________________________
EXAMPLE 5
Investigation of the Action of Paraclox, Glutaraldehyde and Chlorine Bleach Lye on the Pure Enzyme Catalase
Method According to Biurett
Chemicals:
phosphate buffer 0.05M, pH 7.0 (K 2 HPO 4 : 8.7 g/l; KH 2 PO 4 : 6.8 g/l)
enzyme catalase (No. C10 Sigma catalogue)
substrate hydrogen peroxide (30%).
1. Enzyme solution (solution A):
Dissolve catalase in 0.05M phosphate buffer.
Concentration: 50 sigma units per ml of buffer.
1000 ml solution A contains 50,000 sigma units
1600 units=1 mg solid material (C10 catalase)
50,000 units=31.25 mg of solid material (C10 catalase)
The enzyme solution must be used directly.
2. Substrate solution (=solution B)
Dissolve 0.1 ml 30% hydrogen peroxide in 50 ml of 0.05M phosphate buffer (control) or in 50 ml phosphate buffer which contains the stabiliser (substrate). Measure the absorption at 240 nm. The result must lie between 0.550 and 0.520. Possibly dilute the solution or add more hydrogen peroxide thereto.
3. Measurement
2.9 ml of solution B are placed in a quartz cuvette and subsequently mixed with 0.1 ml of solution A. The absorption at 240 nm should, at the beginning of the measurement, amount to approximately 0.450. The time needed for the decrease of the absorption at 240 nm from 0.450 to 0.400 is determined. This time corresponds to the conversion of 3.45 μmol hydrogen peroxide in 3 ml of sample volume.
Result:
Activity
(sigma units total)=3.45: time (minutes calculating back to active sigma units 1 sigma unit reacts 1.0 μmol hydrogen peroxide per minute (at pH 7.0; 25° C.).
______________________________________paraclox glutaraldehyde______________________________________0 sample 0% inhibition 0 sample 0% inhibitionparaclox 0% inhibition glutar- 6% inhibition0.2 ppm aldehyde 0.5 ppmparaclox 16% inhibition glutar- 9% inhibition1 ppm aldehyde 2.5 ppmparaclox 63% inhibition glutar- 11% inhibition2 ppm aldehyde 5 ppm______________________________________
Sodium hypochlorite reacts in solution B with hydrogen peroxide with decomposition before catalase can be added.
EXAMPLE 6
Catalase-dependent Action of Paraclox on the Stability of the Hydrogen Peroxide in a Flotation Experiment
In the case of this experiment, working was analogous to Example 3 but tap water was used instead of process water. The influence of catalase (due to the substantial absence of bacteria) is thereby distinctly reduced. At the same time, in the case of this experiment, the addition of waterglass as stabiliser is omitted.
______________________________________ whiteness after flotation residual R457 Y/C flotate ash peroxide______________________________________0 sample 54.6 58.2 16.7% 46.5% 15%paraclox 0.02% 55.4 59.8 20.7% 50.2% 34.0%paraclox 0.04% 55.8 60.5 18.7% 51.0% 41.0%paraclox 0.08% 55.0 58.8 23.3% 48.4% 52.4%______________________________________
The results show for paraclox a very good stabilising action on the peroxide. This action is not to be attributed exclusively to the inhibition of the catalase and depends upon a side effect which has hitherto not been elucidated.
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The present invention provides a process for the oxidative bleaching of wood pulps and for deinking waste paper by means of hydrogen peroxide and a stabilizing agent, wherein, as stabilizing agent, there is used 2-oxo-2-(4-hydroxyphenyl)-acethydroximic acid chloride (N,4-dihydroxy-α-oxophenylethanimidoyl chloride) of the formula: ##STR1##
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The invention relates to a method for controlling the yarn tension, in particular for weft yarns and warp yarns in a weaving machine and to a weaving machine for performing the method.
BACKGROUND OF THE INVENTION
During the weaving process, the warp yarns are subjected to varying tensions or loads during shed formation and beating and the weft yarn is also subjected to varying tensions during insertion. To compensate the yarn tension, it is a known method to set a predetermined yarn tension for the specific weft process in hand with the aid of a calculated control characteristic and taking account of the yarn tension values.
The disadvantage of this approach is that the control characteristic can only be changed to a limited degree when the weaving machine is running, with the adjustment of the yarn tension being performed manually with the aid of values gained by experience and with the brake adjustment taking place manually with the aid of previously determined braking parameters and yarn properties.
SUMMARY OF THE INVENTION
A control curve is calculated for controlling the yarn tension including warp and weft yarn tensions in a weaving loom by comparing a previously determined yarn tension curve with a desired value for the yarn tension curve. The control characteristic is optimized by continuous iteration. A further optimization of the yarn tension curve takes place by taking account of variable parameters in the yarn tension curve, for example yarn breakage analysis, beat-up force of the reed, and/or shed change. The control device for performing the method can be implemented with conventional logic. The method automatically carries out in an advantageous manner for weft and warp yarns a matching to the optimum yarn tension as a function of time on the basis of preselected parameter values.
The invention aims to remedy this. The invention, as characterized in the claims, satisfies the object of providing a method for controlling the yarn tension, as well as a weaving machine for performing the method, in which the optimum weft yarn tension setting as a function of time is performed automatically on the basis of prespecified values and in dependence on the weaving process and which is suitable for controlling the yarn tension for warp yarns and/or weft yarns.
The invention is described in the following by means of example only with the aid of the enclosed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in the following by means of example only with the aid of the enclosed drawings in which:
FIG. 1 is a diagram with a pre-specified yarn tension curve and a control characteristic produced by the method of the invention;
FIG. 2 is a control structure for producing the control characteristic;
FIGS. 3 and 4 are respectively a diagram of the actual yarn tension value curves and a diagram of the associated control curves taking account of the yarn breakage analysis;
FIG. 5 is a control structure for producing the control characteristic of FIG. 4;
FIG. 6 is a diagram showing the categories in the tension regions when logic is used;
FIGS. 7 and 8 are respectively a diagram of the actual value curves of the warp yarn tension and a diagram of the associated control curves; and
FIG. 9 is a control structure for producing the control curve of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 are now referred to. In a first step, the yarn tension per weft insertion is measured for each rotational angle and, over a particular number of weft insertions e.g. 50, an average value of the yarn tension is determined for each rotational angle. These are shown as actual yarn tension value data in a curve "a". These actual yarn tension value data are subsequently compared with at least one desired value of the yarn tension. A first approximate control curve "b" is then calculated from this comparison. A new actual yarn tension value curve (curve c) then results from this first control characteristic.
In a further step, a further control characteristic with a smaller deviation between desired and actual values than in the first control characteristic is calculated by comparing the new actual value curve with the desired value of the yarn tension. After a selectable number of weft insertions, the control characteristic is introduced into the control loop.
The desired/actual value deviation can be reduced to a minimum by continuing the comparisons further.
Moreover, a systematic variation of the amplitude and/or the phase in relation to the rotational angle is provided for optimizing the control characteristic. The optimization takes place by holding the amplitude of the control characteristic constant and systematically varying the phase, i.e. the position of the control characteristic, in relation to the rotational angle of the main shaft, for example between ±10°, in order to determine the temporal deviation of the control signal. The amplitude and the phase are then subsequently varied alternatingly. The adjustment with the smallest deviation is stored.
For performing the above-described control, a control structure is used, this being shown in FIG. 2. It comprises a control device 1 which is part of a weaving machine control, an adjustment element 2 provided on the weaving machine, a process controlled system, i.e. the course of the yarn, a device 3 for measuring the yarn tension, a device 4 for inputting parameters and an apparatus 5 for determining the control characteristic.
The above-described control and control structure form a basis implementation with which the yarn tension for weft yarns and/or warp yarns can be controlled and which can be used for example in rapier weaving machines and projectile weaving machines.
During the production of cloth, the yarn tension varies a number of times. The following changes are taken account of by the control in accordance with the invention:
1. The position of the relevant adjustment element which is determined ongoingly by a measurement device.
2. The values of the yarn breakage analysis with which the frequency and the point in time of the yarn breakage are determined with the aid of the yarn tension variation in dependence on the rotational angle of the main shaft, and/or the number of yarn breakages is calculated as a function of time statistically.
3. The number of machine stoppages as a result of irregularities in the course of the yarn.
4. The beat-up force of the reed and/or the shed geometry which are determined from the length change of the warp with the aid of the positional change of the adjustment elements (advantageously the yarn rest).
5. The through-pass time of the inserted weft yarn.
6. The fastener or clip inclination of the warp yarn, etc.
Starting from the above-described basis implementation of the control, the control of the yarn tension is now described along its course for a weft yarn in a projectile weaving machine.
The yarn tension curve (curve d) characteristic for a weft insertion is shown in FIG. 3 and the corresponding first control characteristic (curve e) is shown in FIG. 4.
As shown in FIG. 3, the weft yarn curve comprises a braking phase (window 1) during which the yarn is decelerated and a recovery phase (window 2) during which the inserted weft yarn is pulled back by the yarn tensioner.
The optimization of the yarn tension characteristic curve, i.e. the yarn tension as a function of time, takes place in accordance with the above-described basis implementation of the control in that a desired value curve for a weft insertion, i.e. 360 values, is predetermined. The yarn breakage analysis is also taken into account using the criteria "yarn breakage as a result of excessive yarn tension" and "weft insertion failure as a result of to low a yarn tension". When these events occur, the desired value of the yarn tension is determined anew. The yarn breakage analysis takes place advantageously in the braking and/or recovery phase.
The yarn tension curve of a weft yarn is changed, on the one hand, by the braking force and the point in time at which braking is undertaken as well as, on the other hand, by the properties of the yarn. By a later braking point, the maximum yarn tension (curve d) can be brought to below a desired value S1 during the braking phase (window 1). Subsequently, the yarn tension curve falls off during the recovery phase (window 2). The control reacts to this by increasing the braking force whereby the desired value S2 is exceeded, i.e. the desired range is kept within. As a result of these measures, the second control characteristic (curve f) is calculated so that a new actual value curve (curve g) results. If, subsequently, a yarn breakage occurs as a result of too small a force, the desired value S2 is raised whereas, in the case of a yarn breakage as a result of excessive force, the desired value S1 is reduced. The risk of yarn breakages is taken into account in the control in this manner and the optimum braking force setting is achieved.
FIG. 5 shows a control structure for performing the control. This control structure comprises a control device 11 which is part of a machine control (not shown), a magnetically actuatable yarn brake 12, the process controlled system, i.e. the weft yarn curve during weft insertion, a pressure meter 13 whose pressure measurement values are proportional to the yarn tension, a device 14 for determining the control characteristic and a device 15 for prespecifying the yarn tension.
Conventional logic or fuzzy-logic can be provided for the control.
As shown in FIG. 6, for example for the fuzzy-logic for the window 1 the categories "high", "average" and "good" relative to an average yarn tension power are set and for the window 2 the categories "high", "good" and "low" are set, these relating to the absolute values of the yarn tension.
The following rules are given for the adjustment processes:
______________________________________ Braking BrakingWindow 1 Window 2 Force Point______________________________________high high lower laterhigh good -- laterhigh low higher lateraverage high lower --average good -- lateraverage low higher --good high lower earliergood good -- --good low higher earlier______________________________________
Starting from the initially described basis implementation of the control, the control of the course of the yarn is now described in the following for warp yarns in a projectile weaving machine.
In analogy to FIG. 3 relating to the weft yarn tension curve, FIG. 7 shows a typical warp yarn tension curve and FIG. 8 (analogously to FIG. 4) the corresponding first control characteristic.
The yarn tension curve of the warp yarns is, on the one hand, predetermined by the warp let-off motion or warp regulator, the yarn rest and the cloth take-off device and, as shown in FIG. 7, on the other hand, influenced by the beat-up of the reed (window 1) and the opening of the shed (window 2) so that the warp is subject to a changing tension along its course.
In the initially described basis implementation, the average value of the yarn tension over the full width of the warp or at least over a part of the warp is used as the actual value curve and a yarn tension curve over two weft insertions, i.e. 720 values, as the desired value curve.
The optimization of the yarn tension curve takes place in accordance with the basis implementation.
During this optimization the progression of the warp movement is influenced in accordance with the invention by, in particular, taking account of the processes "reed beat-up" (window 1) and "shed opening" (window 2). This is done using a spring model of the course of the warp/cloth. The cloth and the warp yarns have a particular elasticity and have a spring constant which can be calculated in accordance with formula
k=ΔF×L/ΔL
and the value of the spring constant can be determined by tensile measurements. In the above,
ΔF=yarn tension change
L=warp length from the edge of the cloth to the release line of the warp beam
ΔL=warp yarn length change
The warp yarn length change is given by
ΔL=ΔF×L/k.
If L and k are taken as constant it follows that ΔL is proportional to ΔF. ΔF is brought to approaching zero by continuous amplitude and phase optimization. Since this is performed via the tension change at the reed beat-up and via the shed opening, an optimum course of movement of the adjustment element is obtained in an advantageous manner and subsequently a minimum variance in the warp tension.
The warp yarn breakage analysis is additionally included for optimizing the yarn tension curve.
The warp yarn breakage analysis includes yarn breakage as a result of excessive yarn tension as well as the cutting of the warp yarns by the fired projectile or the rapier as a result of to low a yarn tension.
If the yarn tension is too high, then, after the occurrence of a number (for example 10) of yarn breakages typical for this, the desired value of the yarn tension is reduced and the control characteristic determined anew.
The cutting of the warp yarns occurs as a result of the fastener or clip inclination of the warp yarns, i.e. yarns wound on the warp beam remain stuck to one another. This leads to the warp yarns hanging down into the opened shed to them being cut by the insertion member.
The fastener or clip inclination is determined in a static manner with the aid of the yarn breakages which occur over, for example 100 000 weft insertions and the situation is remedied by increasing the desired value of the yarn tension curve.
FIG. 9 shows a control structure for performing the control. This control structure comprises a control device 21 which is part of a machine control (not shown) an actively controllable yarn rest 22, the process controlled system, i.e. the path of the warp yarn from the warp beam to the cloth edge, a pressure meter 23 with measurement values proportional to the yarn tension, a device 24 for determining the control characteristic and a device 25 for presetting or automatically adjusting the desired values of the yarn tension.
Conventional logic elements or fuzzy-logic can be provided for the control.
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A control curve is calculated for controlling the yarn tension including warp and weft yarn tensions in a weaving loom by comparing a previously determined yarn tension curve with a desired value for the yarn tension curve. The control characteristic is optimized by continuous iteration. A further optimization of the yarn tension curve takes place by taking account of variable parameters in the yarn tension curve, for example yarn breakage analysis, beat-up force of the reed, and/or shed change. The control device for performing the method can be implemented with conventional logic. The method automatically carries out in an advantageous manner for weft and warp yarns a matching to the optimum yarn tension as a function of time on the basis of preselected parameter values.
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BACKGROUND OF THE INVENTION
This invention relates to an electronic watt-hour meter which particularly includes a clock circuit and is capable of transferring the display of the measured amount of electric power in accordance with preset time zones and the like and also in accordance with programs.
An ordinary electronic watt-hour meter of the above described type comprises an electric power measuring device for measuring consumed electric power, a clock circuit for generating a clock signal, a data setting device for setting data such as time zones in a day, holidays and the like, to which different charge rates are applied, a memory circuit for memorizing the data set by the data setting device, a central processing unit (CPU) which is operable to write and read the set data into and out of the memory circuit and to designate, in accordance with the set data, a position where the measured value is to be displayed, and a display device for displaying the measured value at the designated position.
In the above described watt-hour meter, the measured value (in watts) is delivered to CPU in the form of a pulse signal, while the clock circuit constantly supplies a clock signal representing the present instant to CPU. The CPU writes and reads the data set by the setting device into and out of the memory circuit, and the display device has a plurality of displaying positions for displaying the measured amounts of electric power as well as the maximum power demand.
With the above described construction of the conventional watt-hour meter, the data such as the time zones, holidays and the like must be set for every individual watt-hour meter, and therefore a data setting device in the form of a keyboard switch has been ordinarily provided in combination with the watt-hour meter. However, since it is essential to prevent unauthorized alteration of the set values from outside, the keyboard switch must be sealed after the completion of the setting operation, thus requiring a considerable amount of time for setting data, although the keyboard switch has an advantageous feature of a general-use construction. Furthermore, the keyboard switch requires a comparatively large space, rendering impossible to reduce the size of the watt-hour meter. In addition, since a watt-hour meter of two, three or four time zones requires a corresponding number of display positions, it is impossible to convert a watt-hour meter of, for instance, four time zones, to that of five time zones.
In the above described conventional watt-hour meter, the power measuring device is provided with an electric power conversion circuit for converting the measured value (in watts) into a pulse signal corresponding to the measured value, and a frequency-divider for dividing the frequency of the pulse signal at desired rates. The output of the frequency-divider is delivered to the CPU.
For eliminating the above described difficulties, there has been proposed a modification wherein the operation of frequency-divider is programmed such that the pulse rate of the output signal is varied in accordance with the time zones and the like. However, nothing has been proposed about the improvement of the data setting device for eliminating the above described difficulties.
SUMMARY OF THE INVENTION
An object of the invention is to provide an electronic watt-hour meter wherein a data setting device is provided detachably for setting data such as time zones and the like and also programs for processing the set data, and after setting the required data, the data setting device is removed from the power meter for minimizing the size thereof.
Another object of the invention is to provide an electronic watt-hour meter wherein a data transmission circuit is further provided for transmitting the data and programs set by the data setting device therethrough to be memorized in a PROM so that various operations can be performed by the same watt-hour meter by changing the data and programs as desired, and wherein the measured electric power is transferred suitably in accordance with the contents of the PROM so as to be displayed on the display device.
These and other objects of the present invention can be achieved by an electronic watt-hour meter comprising a power measuring device, a clock circuit for generating a clock signal, a data setting device for setting data and programs, a data transmission circuit to which the data setting device is connected detachably, a memory circuit which receives the data and the programs set by the data setting device through the data transmission circuit and stores the set data and programs, the memory circuit including a PROM (Programmable Read Only Memory Device) for storing the set data and programs and a ROM (Read Only Memory Device) which preliminarily stores programs required for receiving and memorizing the set data and programs in said PROM through the data transmission circuit, a CPU (Central Processing Unit) which controls the power measuring device in accordance with the set data and programs stored in the PROM, and receives the measured results therefrom, and a display device which displays the measured results under the control of the CPU.
According to this invention, the data setting device detachably connected to the transmission circuit is constructed to set not only the time zones, holidays and the like, but also programs for displaying the measured results with respect to different time zones and also in the form of effective, reactive and apparent electric powers, so that various operations can be carried out by the same watt-hour meter by changing the programs optionally being given by the data setting device as desired. For instance, the way of displaying the measured results may be varied as desired depending on the set programs, so that a watt-hour meter operable in variable number of time zones can be thereby obtained. Furthermore, since the data setting device is constructed to be removable after the completion of the setting operation, the size of the main portion of the watt-hour meter can be substantially reduced, and unauthorized alteration of the setting can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings
FIG. 1 is a block diagram showing a preferred embodiment of the present invention;
FIG. 2 is a block diagram showing an example of a data transmission circuit used in the embodiment shown in FIG. 1; and
FIG. 3 is a timing chart for explaining the operation of the data transmission circuit shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is illustrated an electronic watt-hour meter according to the present invention. An electric power measuring device 1 provided in the watt-hour meter comprises an electric power converting circuit 7 which receives a load voltage V L and a load current I L and delivers an output pulse signal corresponding to the electric power (in watts), and a frequency divider 8 which divides the frequency of the output pulse signal. The output of the frequency divider 8 is supplied to a CPU (Central Processing Unit) 5, which in turn, delivers a frequency dividing ratio setting signal 17 to the frequency divider 8 for providing a pulse signal corresponding to the electric power.
Upon reception of an address signal from CPU 5, a decoder 9 delivers select signals 18A through 18E for selecting the operations of a clock circuit 2, a PROM (Programmable Read Only Memory Device) 10, a ROM 11, a display circuit 12 and a data transmission circuit 14. Among these circuit elements, the clock circuit 2 constantly supplies a clock signal indicative of the present instant to CPU 5 for controlling time zone transferring instants. On the other hand, the PROM 10 and ROM 11, forming in combination a memory circuit, store programs for controlling CPU 5. A data and program setting device 15 is detachably connected to the data transmission circuit through a bus line 16. The PROM 10 and ROM 11 are connected to the CPU 5 through address data bus line 19. The programs stored in the PROM 10 can be rewritten by the program setting device 15 through the data transmission circuit 14 after initially constructed and the programs stored in the ROM 11 cannot be rewritten thereafter, and the PROM 10 and ROM 11 are operated by the read (RD) and write (WR) signals from the CPU 5, respectively. A display device 13 displays the output of the display circuit 12 in terms of digital quantities. The data transmission circuit 14 is also connected to the CPU 5 through the address data bus line 19. The data transmission circuit 14 may be made of, for instance, UART (Universal Asynchronous Receiver Transmitter) 24 as illustrated in FIG. 2, and transmits and receives information to and from the data setting device 15 in a serial manner. In FIG. 2, a switch 26 is provided to be operable in response to the connection and disconnection of the data setting device 15 to and from the data transmission circuit 14. The data transmission circuit 14 includes two monostable multivibrators 25A and 25B. The multivibrator 25A detects a build-up instant of a signal from the switch 26, while the multivibrator 25B detects build-down instant of the same signal, and upon detection of such instants, either of the multivibrators 25A and 25B delivers a pulse signal of a predetermined width. Either of the pulse signals is applied to a reset terminal (RESET) of the CPU 5 as a reset signal for resetting the same. When the data setting device 15 is connected to the data transmission circuit 14, that is, when the data transmission circuit is in the data or program transmitting condition, the circuit 14 further delivers a transmission status signal 20 to AND gates 21A through 21E for controlling the same (see FIG. 1). Furthermore, the select signal 18A delivered from the decoder 9 is applied through the AND gate 21C and an OR gate 22 to a chip select terminal (CS) of the PROM 10. Likewise, the select signal 18B from the decoder 9 is applied through the AND gate 21B and the OR gate 22 to the aforementioned chip select terminal (CS) of the PROM 10. A read signal and a write signal (RD) and (WR) from the CPU 5 are both applied to the PROM 10. That is, the read signal (RD) is applied to the PROM 10 through an AND gate 21E. On the other hand, only the read signal (RD) from the CPU 5 is applied to the ROM 11 through an AND gate 21D. The ROM 11 stores programs for controlling the transmission circuit 14 and also for controlling the writing operation of the data and the programs into the PROM 10.
The electronic watt-hour meter of the above described construction operates as follows.
In a case where the data setting device 15 is not connected to the data transmission circuit 14 through the data bus line 16, the transmission status signal 20 is brought to "0", whereas when the setting device 15 is connected, the status signal 20 is brought to "1". By applying the status signal 20 at "1" level, an access to the ROM 11 of the CPU 5 by way of the select signal 18B and the read signal (RD) is made possible. Furthermore, when the status signal 20 is at "1" level, one of the inputs to the AND gate 21C is made "1", and hence a writing operation into the PROM 10 by use of the select signal 18A and a write signal is made possible.
FIG. 3 is a timing chart indicating the above described operations. At the same time when the transmission status signal 20 becomes "1", the monostable multivibrator 25A operates to deliver a pulse signal, a reset signal 23 thereby resetting the CPU 5. As a consequence, the CPU 5 executes programs starting from the 0 address for delivering a select signal 18B. The select signal 18B is applied to the ROM 11 through the AND gate 21A, thereby to operate CPU 5 in accordance with the instructions stored in the ROM 11. That is, in a period T 2 shown in FIG. 3, CPU 5 receives data and programs set by the data setting device 15 through the UART 24, and writes the data and programs into the PROM 10. At this time, the PROM 10 is controlled by the select signal 18A and the write signal.
Upon termination of the writing operation in the PROM 10, the data setting device 15 is disconnected from the data transmission circuit 14 so that the transmission status signal 20 is brought to "0" level. At this time, since one of the inputs of the AND gates 21B and 21E is brought to "1", the read signal RD and the select signal 18B are applied to the PROM 10. In this case, since one of the inputs of the AND gate 21C is held at "0", the select signal 18A is not applied to the PROM 10. Furthermore, the application of the read signal and the select signal to the ROM 11 is prohibited by the AND gates 21D and 21A, so that the access of the CPU 5 to the ROM 11 is prohibited at this time. In addition, at the same time with the build-down of the transmission status signal 20, another monostable multivibrator 25B operates to deliver the reset signal for resetting CPU 5 (during an interval T 1 in FIG. 3), and therefore the CPU 5 executes the programs starting from 0 address of the PROM 10.
Summarizing the above description, during the time period T 1 in the timing chart, CPU 5 operates in accordance with the contents of PROM 10, while in the interval T 2 , CPU 5 operates in accordance with the contents of ROM 11. The frequency dividing ratio of the frequency divider 8 provided in the power measuring device 1 is set to a predetermined frequency dividing ratio when the CPU 5 operates according to the contents of the PROM 10, and hence the output of the power converting circuit 7 is converted into the corresponding value, and is received in the CPU 5. The displaying device 13 which displays the value obtained in the display circuit 12 may be a dot-matrix type liquid crystal display device (LCD), a plasma display device, cathode ray tube (CRT) and the like, the displayed values being controlled by the CPU 5 through the display circuit 12 in accordance with the programs set by the data setting device 15 and now stored in the PROM 10 so that the measured electric power is displayed on the display device with respect to different time zones and also in the form of an effective electric power, reactive electric power and an apparent electric power (in volt-ampere-hour), for example.
In the above described embodiment, although a ROM 11 and a PROM 10 have been provided in the memory circuit as its essential components, in a case where the CPU 5 includes a mask ROM, only a PROM may be provided in the memory circuit. In such an arrangement, it is apparent that the advantageous effect similar to those obtained by the above described embodiment can also be obtained by the modified arrangement when the transmission status signal used in the embodiment is utilized as a transfer signal between the mask ROM and the PROM.
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In an electronic watt-hour meter including a power measuring device and a clock circuit, a data setting device for setting data such as time zones, holidays and the like and programs is detachably connected to a data transmission circuit, while a PROM for storing the set data and programs and a ROM for storing programs required for receiving the set data and programs through the data transmission circuit and storing the same in the PROM are provided in a memory circuit. Under the control of a CPU, an electric power measured by the power measuring device is processed in accordance with the data and the programs stored in the PROM and displayed on a displaying device, while the data setting device itself is removed from the watt-hour meter after the data and the programs have been memorized in the PROM.
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BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates to cardiac leads used in combination with a cardiac rhythm management device, e.g., heart pacemakers or defibrillator, to monitor and control the rhythm of the heart. This invention is more particularly directed toward lead configurations adapted to be implanted in the coronary veins on the left side of the heart and to methods for implanting such leads.
II. Discussion of the Prior Art
As explained in U.S. Pat. No. 4,928,688 to Morton M. Mower dated May 29, 1990, under normal circumstances impulses from the SA node affect contraction of the atria and then propagate to the AV node. The AV node then emits a second nerve impulse which affects contraction of the ventricles. In healthy individuals this is done in a coordinated manner to circulate blood through the body. However, many patients suffer from conditions which inhibit the transfer of nerve impulses from the SA node to the AV node and from there to the ventricles. In such cases, the chambers of the heart do not contract in a coordinated fashion and hemodynamic efficiency of the heart is decreased. This has profound adverse implications for the health and well-being of the patient. In minor cases, the quality of life is considerably reduced. More severe cases can result in death.
The Mower U.S. Pat. No. 4,928,688 describes a method for improving the hemodynamic efficiency of a sick heart. The method proposed in that patent is to place electrodes in both the right and left ventricles, monitor the cardiac signals originating in the right and left ventricles, analyze these signals and the absence thereof in a control circuit, and provide stimulating pulses to one or both ventricles within a time interval designed to improve the heart's hemodynamic efficiency.
Others have discussed the advantages of implanting leads in both the right and left ventricles to permit a sick heart to be more effectively defibrillated. See, for example, U.S. Pat. No. 4,922,407 to Williams; U.S. Pat. No. 5,099,838 to Bardy; and U.S. Pat. Nos. 5,348,021, 5,433,729, and 5,350,404 all to Adams et al. Each of the patents describe inserting a lead through the right atrium and coronary sinus into one of the coronary veins. None of these patents, however, discuss the difficulties encountered in doing so.
Important health advantages are achieved by positioning an electrode in a branch of the great vein of the heart. A lead so positioned can be used to stimulate the left ventricle. While it would be possible to position the electrode within the left ventricle, this can increase the potential for clot formation. If such a clot were released to the brain, the situation could be life threatening. However, traditional leads are not well suited for implantation in the coronary vein. Traditional leads tend to be too big, tend to have some type of fixation device (such as tines or a screw) that must be altered to advance the lead into the sinus, or tend to require a style for positioning which is not flexible enough to negotiate the coronary vessels.
An arrangement intended to address such difficulties associated with the implantation of leads is disclosed in U.S. Pat. No. 5,304,218 granted to Clifton A. Alertness on Apr. 19, 1994. The arrangement disclosed in this patent includes a lead having an electrode. The electrode has a follower means for slid ably engaging a guide wire. The electrode is implanted by feeding the guide wire along the desired path, engaging the follower means to the guide wire, advancing the lead along the guide wire until the electrode resides at the implant site, and retracting the guide wire from the follower means after the electrode is implanted at the implant site.
A review of the specification and drawings of U.S. Pat. No. 5,304,218 and an understanding of the anatomy and physiology of the heart demonstrates several problems with this approach. First, the path through which the lead must be fed is very restricted. The increased size of the distal end of the lead, given the presence of the follower, may make it more difficult to advance such a lead along the desired path so as to be positioned on myocardial tissue of the left ventricle. Second, the direction of blood flow through the veins tends to force electrodes implanted there out of the vein. This problem is likely to be exacerbated by the increase in the profile area of the distal end given the presence of the follower. Third, the profile of the distal end of a lead implanted in a coronary vein may need to be made as small as possible to limit occlusion and permit blood to flow as freely as possible through the blood vessel when the lead is in place and to limit damage to the vessels and/or myocardium.
SUMMARY OF THE INVENTION
The present invention provides an improved lead for implantation of an electrode into a coronary vein on the left side of the heart. The lead includes an elongated, flexible body member made of an electrically insulative material. The body member includes a proximal end and a distal end. A lumen extends through the body member from the proximal end toward the distal end. The lumen may extend all the way to the distal end so that the distal end includes an opening. The lead also includes a conductive member extending through the body member from the proximal end toward the distal end. Electrically coupled to the conductive member near its distal end is an electrode. Additional lumens, electrodes and conductive members may be included within and on the lead body.
Leads made in conformance with the present invention can be inserted in a number of different ways. For example, a guide catheter can be inserted and then the lead passed through the guide catheter until it is properly positioned. The lead can be coated with a lubricious coating to reduce friction in the guide catheter. The guide catheter can then be retracted. Similarly, a guide wire can be advanced to the implant site alone or through a guide catheter. Using the open distal lumen, the lead can be slid over the guide wire until the electrode is properly positioned. The guide wire or guide catheters can then be retracted. Also, the lead can be temporarily fixed to a guide catheter. The fixate may be designed to be dissolved by body fluids. The lead is then inserted along with the guide catheter. After the electrode is in place and the fixate dissolves, the guide catheter can be retracted.
Alternative embodiments of the present invention offer other advantages and features. For example, the wall of the lumen can be coated with a lubricious coating or a polymer with a low coefficient of friction to reduce friction between a guide wire and the wall of the lumen. The lumen can also be used to deploy a separate electrode past the distal end of the lead's body member. Additional lumens can be provided and the cross-section of the body member can be modified to provide a channel for a guide wire. These features are shown in the drawings and discussed in further detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an intravenous cardiac lead having an electrode positioned in a coronary vein.
FIG. 2 is a cross-section of a distal end portion of the intravenous cardiac lead shown in FIG. 1.
FIG. 3 is a longitudinal cross-section view of a distal end portion of an intravenous coronary lead of the present invention with a tapered end and deployable electrode.
FIG. 4 is a longitudinal cross-section of a distal end portion of an intravenous coronary lead inserted within and temporarily fixed to a guide catheter.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a human heart 1 with the intravenous coronary lead 10 of the present invention passing through the superior vena cava 2, the right atrium 3, and the coronary sinus 4 into the great vein of the heart 5 so that a surface electrode 12 on the lead 10 is implanted in a branch of the coronary vein. When positioned as shown, the electrode 12 can be used to sense the electrical activity of the heart or to apply a stimulating pulse to the left ventricle 7 and without the need of being in the left ventricular chamber.
FIG. 2 shows in greater detail the structure of the intravenous coronary lead shown in FIG. 1. As shown in FIG. 2, the lead 10 includes an elongated body member 14 having a proximal end 16 and a distal end 18. The body member 14 is preferably made of a flexible, electrically insulative material. The outer surface of the body member 14 is preferably treated to prevent fibrotic attachment and to reduce inflammation response to the lead. Such a treatment could include a carbon coating, a steroid embedded in the material, a steroid eluting collar, or the like.
The body member 14 encapsulates a flexible electrically conductive member 20 extending from the proximal end 16 toward the distal end 18 of the lead's body member 14. Conductive member 20 is shown as a flexible wire coil in FIG. 2. Alternatively, the conductor member 20 could be in the form of a conductive wire, a thin ribbon, a plurality of fine wires formed as a cable, or a flexible tube without deviating from the invention.
FIG. 2 also shows the lead 10 as including a central lumen 22 extending from the proximal end 16 to the distal end 18 of the body member 14. In fact, in this embodiment, there is an opening 24 through the distal end 18 to the lumen 22. A coating of a material such as polytetrafluoroethylene (Teflon) preferably forms the wall 26 of the lumen 22 to increase its lubricity. The coating material, of course, could be some other polymer having a low coefficient of friction.
The electrode 12 shown in FIG. 2 is preferably created by removing an annular portion of the insulative body member 14 to expose a portion of the underlying conductive member 20. When the conductive member 20 is a coil as shown in FIG. 2, the turns of the coil can be melt-banded such as by application of laser energy, to form the surface electrode 12. Those skilled in the art will recognize that a ring electrode electrically coupled to the conductive member 20 will also suffice. Likewise, the position of the electrode 12 along the body member 14 can be changed. Certain advantages may be achieved, for example, if the electrode 12 is at the tip of the lead.
The lumen 22 can be put to many uses. For example, a surgeon can advance a guide wire through the coronary sinus and coronary veins to the proper position for the electrode 12. The free proximal end of the guide wire can then be inserted through the opening 24 in the distal end 18 and the lead 10 slid over the guide wire to position the electrode 12. The guide wire can then be retracted through the lumen 22. The lumen 22 can also be used to insert a small separate structure with an electrode or sensor deployable beyond the tip of the lead. This allows separation of the electrodes and can be used for bipolar pacing or for a combination of pacing and defibrillation. Likewise, the lumen could be used to inject a contrast fluid to facilitate fluoroscopic viewing. The lumen can also be used to deploy a fixation mechanism, deploy an extraction mechanism, or deploy a plug to close the opening 24 and seal the lumen.
FIG. 3 shows how the lead 10 can be modified to provide a tip 40 of a reduced diameter. The body member 14 of lead 10 has a distal end 18 with an opening 24 in communication with the lumen 22. FIG. 3 shows how the lumen 22 can be used to deploy a separate structure such as second, miniaturized lead 42. The deployable lead 42 has a lead body 44, an electrode 46 and a conductive member (not shown) coupled to electrode 46 and running from the electrode 46 to the proximal end of the lead body 44. The lead body 44 may be designed to coil after it exits the lumen to fix the electrode 46 in the correct position. FIG. 3 also shows a ring electrode 47 surrounding a portion of the tip 40. The ring electrode 47, when present, is electrically coupled to conductive member 20. Additional electrodes and conductors can be added for sensing, pacing or defibrillating as desired. As indicated above, the ring electrode can also be formed by exposing and laser bonding the coils of the conductive member 20. The electrode 46 may be multipolar. It can be used for defibrillating and the electrode 47 is used for pacing. Alternatively, electrode 46 may be used for pacing and the electrode 47 used for pacing. Electrodes 47 and 46 could also be used for sensing electrical activity of the heart. Electrodes 47 and 46 can also be used together for bipolar pacing. Without limitation, the main portion of body member 14 could have an outside diameter in the range of 0.020 inches to 0.100 inches. If, for example, the main portion of the body member has an outside diameter of 0.058 inches, the diameter of the tip 40 could have an outside diameter of approximately 0.046 inches and the deployable lead 42 could have an outside diameter of 0.014 inches. When used, the main lead body can be positioned first over a guide wire. Once the lead is in place the guide wire is removed and replaced with the deployable structure which can be advanced beyond the tip of the larger lead body.
FIG. 4 is provided to assist in explaining an alternative method for implanting an electrode 12 in a coronary vein. As shown in FIG. 4, the lead 10 is loaded and temporarily fixed to the inside of a guide catheter 70 designed to be placed in the coronary sinus. The fixation means 72 may consist of a material such as mannitol which will dissolve after short exposure to blood. Once the guide catheter 70 is properly positioned and the fixation means 72 is dissolved, the guide catheter 70 can be retracted leaving the lead in place with an electrode at a desired position. The lead can then be advanced further if necessary using a stylet and/or guide wire as previously described.
While not shown in any of the views, each lead will have one or more connectors of a type known in the art at its proximal end for mating with the pacer and/or defibrillator pulse generator whereby depolarization signals originating in the heart can be sensed and stimulating pulses applied in accordance with the device's control algorithms.
The foregoing discussion is intended to illustrate various preferred arrangements for meeting the objections of the present invention. Modifications and variation can be made by those skilled in the art without departing from the invention. Accordingly, the invention is limited only by the scope of the following claims which are intended to cover all alternate embodiments and modifications as may fall within the true scope of this invention.
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Intravenous cardiac leads having at least one electrode intended to be implanted within the coronary veins are disclosed. Also disclosed are structures and techniques for advancing such leads through the atrium and coronary sinus into the coronary veins overlaying the left ventricle.
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FIELD OF THE INVENTION
[0001] The present invention relates to automobile racetracks and their design and more particularly to automobile racetrack designs that are capable of accommodating several different types of automobile racing.
BACKGROUND OF THE INVENTION
[0002] When auto racing started in Europe at the beginning of the 1900's it generally took place through the countryside on standard roads. This tradition has continued down to the present with the typical European auto race taking place on a road type of circuit. On the other hand in the United States at the beginning of the 1900's auto racing started on rundown horse racing tracks. This tradition has substantially continued to the present with the typical auto race venue being on a dedicated oval circuit with some exceptions. Additionally, professional auto racing of various types has become multibillion-dollar sport/entertainment industry.
[0003] Over the years auto racing has fragmented into several different forms, which in many respects are or may become mutually exclusive. A number of the major variations are Formula 1 (F-1) (A privately owned, Europe based, international series running formula autos on road circuits), Championship Auto Racing Teams (CART, a publicly traded U.S. based corporation that sponsors an international series running formula autos on road, street, oval and mixed circuits.) and National Association of Stock Car Auto Racers (NASCAR), (Privately owned, U.S. based, National Series Running “stock” cars on 99% oval mix and 2% road circuits).
[0004] One of the more recent fractures in auto racing occurred in the mid-1990's when the Indianapolis Motor Speedway (IMS) and CART parted ways, leading to the creation of the Indy Racing League (IRL), (A privately owned, U.S. based, National series running formula cars on a variety of oval mix circuits). Given the fact that sponsors, fans and contracts with broadcast outlets are limited the more fractured the sport becomes the less it will be able to sustain the concentration of money and fans necessary for the sport to survive and thrive.
[0005] As noted the IRL Series confines their racing to an oval type racetrack when the car moves around the oval in one direction and makes each turn in only one direction. Racing on oval tracks began on horse tracks and since horses' raced in a counter clockwise direction with only left turns modern auto racing continues this tradition. The cars in this type of racing are thus designed to turn only to the left during the race and consequently a number of mechanical, structural and aerodynamic design features of this form of racing machine are intended to optimize the operation of the car and the safety of the driver under the conditions for racing on an oval circuit in one direction.
[0006] Presently, CART incorporates a more flexibly designed car suitable for racing on oval, street or road circuits and where there are turns to both the left and right. The fissure between CART and IMS resulted in part from IMS mandated requirements regarding engine power and design, and chassis rules for the INDY 500 (An IMS Corp., Race) in order to slow the cars down. At the time of this fissure CART had 20 other races in its series and was locked into engine contracts that specified engines which did not meet the engines design mandated by IMS's. CART'S powerful engines were too fast for IMS thus CART and IMS parted ways. IMS started its own series, the IRL, with a more restrictive engine formula in order to slow the speeds down on ovals. CART went on its way without the INDY 500 as its showcase event while IMS with the establishment of IRL continued developed its own series of events.
[0007] Since CART cars do not have the design limitations mandated by IRL they can achieve higher speeds than IRL cars. However, this fact in itself causes problems in that on some racetracks, in particular oval ones. CART cars can reach speeds of over 240 miles per hour. Since the turns of the typical high performance oval racetrack are steeply banked the cars can enter the curves at speeds of 240 miles per hour or more. At these speeds the driver experiences forces equivalent to two to three G's, similar to that experienced by jet fighter pilots, only in a different direction, i.e. laterally. Thus in a race on an oval track in which a car completes one circuit of the track in a half a minute or less the driver may experience these forces two or three times over the course of half a minute. From experience it has been determined that an individual undergoing periodic G forces more frequently than every 40 to 50 seconds will have a tendency to black out. Additionally, G-suits used by fighter pilots are useless in a racing car since a pilot only experiences an up and down force while that experienced by a racing car driver also to the side, lateral.
[0008] The situation become so bad that on Apr. 29, 2001 the President of the CART had to cancel a race, the Firestone Fire hawk 600, scheduled at the Texas Motor Speedway. During trials the drivers were experiencing excessive G forces in the turns and there was a fear that in the drivers attempts to perform at maximum possible speeds some of the drivers might black out with catastrophic consequences. Texas Motor Speedway like many other oval tracks have high-banked corner's that allow the cars to maintain their maximum speeds in the turns. Additionally the Texas Motor Speedway had no straights of significant length to give the drivers a break. Drivers were thus experiencing G forces a majority of the time in each lap. On the other hand although IMS has long straights it has tow-banked 90-degree corners with no runoff but the drivers are still able to maintain speed without lifting off the throttle.
[0009] Although street courses can be set up to inhibit the speed at which CART autos run at they usually provide a spectator only a limited view of the race unlike an oval track which usually allows a spectator a view of substantially most of the race. Additionally, street courses lack the efficiency and crowd control features of an oval track. Since one of the purposes of auto racing is to make money for its promoters and participants oval or enclosed tracks that allow for optimal crowd placement and control are much more desirable than open road courses. Typically, several different types of racecourses can be placed inside the confines of an oval track including a street type of course for Formula 1 racing. However, one of the limitations of an oval track are the limited design options for IRL racing autos which are designed to turn in one direction during a race, to the left.
[0010] Given present design techniques available for oval auto racecourses and the need to limit turns to one direction around the entire course the options available for IRL type of tracks are severely limited. Most oval courses are limited in total acreage and if made too big in area Lose the advantage associated with an oval track. Only so many turns can be introduced into an oval course and then it simply becomes a circular course.
[0011] Thus, what is needed is some means to reverse the effects of fragmentation within auto racing and allow each of the different racing series to compete at the same facility, but not on the same circuit. Such a racecourse would have the advantage of limiting all turns to the left for certain types of races while increasing the distance and number of corners of the track, much like a road course.
SUMMARY
[0012] It is an objective of the present invention to provide a multifunction racecourse; one that most if not all forms of auto racing can be conducted. It is an additional objective to provide a racetrack on which the speed of the cars can be controlled to avoid having the drivers exposed to excessive and prolonged G-forces. It is still another objective of the present invention to provide a racetrack design that can be easily retrofitted on to existing racetracks.
[0013] The present invention accomplishes these and other objectives by providing a racetrack design that includes one exterior complete closed circuit and at least one interior loop, the at least one interior loop connecting to the exterior closed circuit at two points, the exterior closed circuit and at least one interior loop being configured such that a racer can make a continuous movement starting from and returning to the same point by moving around substantially all of the closed circuit and all of the loop while making turns in only one direction and the loop includes at least one overpass so that the one continuous movement by the racer can be made without touching any portion of the at least one loop and the closed circuit more than once before passing the start tine a second time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention wilt be better understood by an examination of the following description, together with the accompanying drawings, in which:
[0015] [0015]FIG. 1 depicts a prior art oval racetrack;
[0016] [0016]FIG. 2 depicts a racetrack made according the present invention;
[0017] [0017]FIG. 3A depicts a raised view of a crossover or overpass that allows the racetrack of the present invention to pass over itself in a nongrade crossing;
[0018] [0018]FIG. 3B depicts a lower roadway view of a crossover or overpass that allows the racetrack of the present invention to pass over itself in a nongrade crossing;
[0019] [0019]FIG. 4 depicts an inverted figure eight variation of the racetrack of the present invention;
[0020] [0020]FIG. 5 depicts a variation of the racetrack of the present invention with two crossovers and two additional ovals; and
[0021] [0021]FIG. 6 depicts another version of the racetrack of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The present invention provides a design for a racecourse that incorporates unique design elements that allow for the incorporation of the best features of both IRL course requirements but with a flexibility that allows for the racing of CART type of cars in a controlled speed environment. The present invention does this by adding at least one underpass or bridge on the racecourse to allow the track to turn back or loop back on itself. The use of a bridge or underpass, i.e. a nongrade or nonlevel crossing, and thus avoids a grad crossing giving the cars the ability to move over the entire course without stopping. FIG. 1 depicts a very basic prior art oval racecourse 21 with four turns. FIG. 2 depicts a racecourse made according to the present invention that is set up with an outer oval 23 and inner oval 25 . Roads 27 and 29 connect the outer oval 23 and inner oval 25 with a crossover at 31 . The crossover is either a bridge or underpass to avoid a level crossing. The start of a race might be at 33 and the flow of the race could follow the arrows 34 around the track. As can be seen all of the turns the racecars would make during the race would be to the left around the track. Naturally, it is possible to reverse the direction and make all of the turns to the right. Having the turns all go in one direction meets one of the major requirements of IRL type of cars.
[0023] One of the advantages of this set up of the racetrack according to the principles of the present invention is that a variety of straight-aways of varying lengths and turns at various positions can be incorporated into the design of the racetrack. This type of setup will allow for the control of the speed of the cars. The setup depicted in FIG. 2 allows only one very high-speed turn at 37 that the cars reach after passing down the Long opening straightaway 39 . The rest of the turns either do not have an approach straightaway Long enough to gain maximum speed or the approach straightaway ends at a very sharp turn that requires the car to slow down substantially. The advantage of this aspect is that it limits the track to one turn in which the driver will experience substantial G-forces. The other long straightaway 38 ends in a sharp turn 40 that require the racing car driver to slow down significantly to make the turn. The racetrack depicted in FIG. 2 provides two different racecourses. The first being around the entire out side oval 23 including section 42 . The second racecourse is around the inside oval 25 and the outside oval 23 with the exception of section 42 of the outside oval. Thus, one could safely run IRL racing cars around the first racecourse the entire outside oval and CART, Formula 1 and IRL racing cars around the second racecourse consisting of most of the outer oval 23 and all of the inner oval 25 .
[0024] [0024]FIG. 3A provides a view of a crossover 43 of the present invention. The crossover is a bridge, overpass or underpass that allows the racetrack to loop back on itself without the need of a grad crossing. This arrangement allows the racecars to move continuously around the track and not have to periodically stop for traffic. The crossover can be a typical concrete or metal bridge. A car 44 on lower roadway 47 has just passed under the bridge 46 of over pass 43 . FIG. 3B provides a view from lower roadway 47 of overpass 43 and bridge 46 that forms the overpass.
[0025] A racetrack constructed according to the present invention would be made with a concrete roadway. The roadway will be banked at a number of the important turns while some of the sharper turns will not be banked much at all to provide for control the speed of the cars during the race. The present description, other than describing the set of the racecourse, does not include a detailed discuss of the construction of a racetrack since those skilled in the art, once they read and understand the principles of the present invention, will be able to construct a racetrack according to the present invention based on generally known racetrack construction principles.
[0026] One of the key features of the present invention is that the ovals 23 and 25 of the track progressively turn in towards a common center as depicted in FIG. 2. Thus, an existing oval racetack could be easily modified to incorporate the present invention without the need for expanding onto more land. The infield of the existing track would be used for the added oval or ovals as the case maybe. In fact the track set up depicted in FIG. 2 could be very easily retrofitted onto an existing oval racetrack. The original oval of the racetrack being oval 23 and the new oval being oval 25 with roadway section 27 and 29 connecting the two ovals. Naturally, crossover 31 would be included to complete the racecourse. The outside oval 23 on a typical racecourse might be 2.6 miles or 4.2 kilometers in total circumference. Thus, the addition of an interior loop or oval 25 might add from three quarters of a mile to 1.5 miles to the entire racecourses. One of the unique advantages of the present invention is that spectators sitting in typical racetrack grandstands 45 located around the periphery of the outside oval 23 will be able to see a significant portion of the race on both the inside and outside ovals 23 and 25 . Additionally, there will still be enough room for the pit stop area 47 .
[0027] Since the racecourse of the present invention can be constructed within the parameters of a typical oval racetrack the operators of a racetrack of the present invention will be able to exercise good crowd control and be able to tightly control access to races conducted on the racecourse. In fact there would not have to be any modification of existing systems of crowd control or control of access.
[0028] [0028]FIG. 4 shows a variation of the racecourse of the present invention in the form of an inverted figure eight 51 . Racecourse 51 includes a crossover or overpass 53 . Racecourse 51 has outer loop 55 and inner loop 57 . Additionally, by adding roadway 52 it becomes a modified figure eight design.
[0029] [0029]FIG. 5 shows yet another variation of the present invention in which the racecourse 71 has one outer oval 73 and two inner ovals or loops 75 and 77 . In this configuration the racecourse 71 has two crossovers or overpasses 82 and 84 to allow the racecourse to pass over itself and avoid a grad crossing. As can be seen all three ovals or loops 73 , 75 and 77 have a common center area 85 .
[0030] [0030]FIG. 6 provides a variation of the present invention on which just about all forms of auto racing could be run including CART, IRL, Formula One, NASCAR and drag racing. The racetrack 90 includes an outside oval 91 an inside oval or loop 93 with a crossover 95 . However, the racecourse also includes one long center straightaway 97 that could be used for drag racing. Also, racetrack 90 includes a meandering portion of the racecourse 99 that starts from outside oval 91 at point 101 and rejoins outer oval 91 at point 103 .
[0031] This meandering course together with oval could form the basis of a Formula One course. Inner oval 93 and outer oval 91 could form IRL and CART racecourses. Additionally, outer oval 91 could form a NASCAR racecourse. Racetrack 90 has the standard grandstands 107 located around the outside periphery of outer oval plus the standard pit areas 109 .
[0032] While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made to it without departing from the spirit and scope of the invention.
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A racetrack designed to accommodate various types of auto racing class including Indy, CART, Formula 1 etc. is disclosed. The race track of the present invention is a continuous closed circuit track with at least two loops which loop about a common center area and with track passing over itself at least once by a nonlevel crossing such as an overpass so that the track does not have a level crossover and thereby allowing a vehicle making an entire circuit of the track the option of only making turns in one direction and not passing over any portion of the track more than once is a single circuit of the track.
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BACKGROUND
In human hearing, hair cells in the cochlea respond to sound waves and produce corresponding auditory nerve impulses. These nerve impulses are then conducted to the brain and perceived as sound.
Hearing loss, which may be due to many different causes, is generally of two types: conductive and sensorineural. Conductive hearing loss typically occurs where the normal mechanical pathways for sound to reach the hair cells in the cochlea are impeded, for example, from damage to the ossicles. Conductive hearing loss may often be helped by using conventional hearing aids that amplify sounds so that acoustic information can reach the cochlea and the hair cells. Some types of conductive hearing loss are also treatable by surgical procedures.
Many people who are profoundly deaf, however, have sensorineural hearing loss. This type of hearing loss can arise from the absence or the destruction of the hair cells in the cochlea which then no longer transduce acoustic signals into auditory nerve impulses. Individuals with sensorineural hearing loss may be unable to derive significant benefit from conventional hearing aid systems alone, no matter how loud the acoustic stimulus is. This is because the mechanism for transducing sound energy into auditory nerve impulses has been damaged. Thus, in the absence of properly functioning hair cells, auditory nerve impulses cannot be generated directly from sounds.
To overcome sensorineural deafness, cochlear implant systems, or cochlear prostheses, have been developed that can bypass the hair cells located in the cochlea by presenting electrical stimulation directly to the auditory nerve fibers. This leads to the perception of sound in the brain and provides at least partial restoration of hearing function. Most of these cochlear prosthesis systems treat sensorineural deficit by stimulating the ganglion cells in the cochlea directly using an implanted electrode or lead that has an electrode array. Thus, a cochlear prosthesis operates by directly stimulating the auditory nerve cells, bypassing the defective cochlear hair cells that normally transduce acoustic energy into electrical activity in the connected auditory nerve cells.
Prior to stimulating the nerve cells, the electronic circuitry and the electrode array of the cochlear prosthesis separate acoustic signals into a number of parallel channels of information, each representing a narrow band of frequencies within the perceived audio spectrum. Ideally, each channel of information should be conveyed selectively to a subset of auditory nerve cells that normally transmit information about that frequency band to the brain. Those nerve cells are arranged in an orderly tonotopic sequence, from the highest frequencies at the basal end of the cochlear spiral to progressively lower frequencies towards the apex.
A cochlear implant system typically comprises both an external unit that receives and processes ambient sound waves and a cochlear implant that receives data from the external unit and uses that data to directly stimulate the auditory nerve. A cochlear implant is a surgically implanted electronic device having electrodes that reside in the cochlea of a patient's ear and provides a sense of sound to the patient who is profoundly deaf or severely hard of hearing. In a typical cochlear implant, a microphone receives sound and converts it into electrical signals. These electrical signals are transmitted to a processor. Typically, the processor is implanted in the patient's body and is connected to an array of electrode contacts which are implanted within one of the cochlear ducts, such as the scala tympani. The processor receives the electrical signals and transmits them down a bundle of wires to specific electrode contacts. The electrode contacts then generate electrical fields which stimulate the auditory nerve. This provides the patient with a sense of hearing.
One challenge in constructing and surgically inserting a cochlear device is managing the delicate wires which connect the processor to the electrode contacts. To minimize the trauma to the patient, the wires have a small diameter. However, during manufacturing and insertion, extra precautions are required to maintain the organization of the wire bundle and to protect the wire bundle from kinking. Damage to the wires can result in decrease performance or failure of the cochlear implant.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate various embodiments of the principles described herein and are a part of the specification. The illustrated embodiments are merely examples and do not limit the scope of the claims.
FIG. 1 is an illustrative diagram showing a cochlear implant system in use, according to one embodiment of principles described herein.
FIG. 2 is a diagram showing external components of an illustrative cochlear implant system, according to one embodiment of principles described herein.
FIG. 3 is a diagram showing the internal components of an illustrative cochlear implant system, according to one embodiment of principles described herein.
FIG. 4 is a perspective view of an illustrative electrode array being inserted into a cochlea, according to one embodiment of principles described herein.
FIGS. 5A and 5B are a perspective view and cross-sectional view, respectively, of one illustrative embodiment of an electrode which shapes a wire bundle, according to one embodiment of principles described herein.
FIG. 6A is a side view of an illustrative cochlear lead which includes an integrated wire carrier, according to one embodiment of principles described herein.
FIGS. 6B-6E are cross-sectional views of illustrative integrated wire carriers, according to one embodiment of principles described herein.
FIG. 7 is a side view of an illustrative cochlear lead which includes an integrated wire carrier, according to one embodiment of principles described herein.
FIG. 8 is a side view of an illustrative cochlear lead which includes an integrated wire carrier, according to one embodiment of principles described herein.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
DETAILED DESCRIPTION
As mentioned above, individuals with hearing loss can be assisted by a number of hearing devices, including cochlear implants. To place the lead of a cochlear implant, the distal (or apical) portion of a cochlear lead is pushed through an opening into the cochlea. The distal portion of the lead is typically constructed out of biocompatible silicone, platinum-iridium wires, and platinum electrodes. This gives the distal portion of the lead the flexibility to curve around the helical interior of the cochlea. During manufacturing, the proper management of wires which pass through the lead and connect to electrodes avoids damage to the wire or flawed assembly of the lead.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present systems and methods. It will be apparent, however, to one skilled in the art that the present systems and methods may be practiced without these specific details. Reference in the specification to “an embodiment,” “an example,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least that one embodiment, but not necessarily in other embodiments. The various instances of the phrase “in one embodiment” or similar phrases in various places in the specification are not necessarily all referring to the same embodiment.
The electrode array to be implanted in the scala tympani typically comprises a thin, elongated, flexible carrier containing several longitudinally disposed and separately connected stimulating electrode contacts, conventionally numbering about 6 to 30. Such an electrode array is pushed into the scala tympani duct in the cochlea, typically to a depth of about 13-30 mm via a cochleostomy or via a surgical opening made in the round window at the basal end of the duct.
In use, the cochlear electrode array delivers electrical current into the fluids and tissues immediately surrounding the individual electrode contacts to create transient potential gradients that, if sufficiently strong, cause the nearby auditory nerve fibers to generate action potentials. The auditory nerve fibers branch from cell bodies located in the spiral ganglion, which lies in the modiolus, adjacent to the inside wall of the scala tympani. The density of electrical current flowing through volume conductors such as tissues and fluids tends to be highest near the electrode contact that is the source of such current. Consequently, stimulation at one contact site tends to selectively activate those spiral ganglion cells and their auditory nerve fibers that are closest to that contact site.
FIG. 1 is a diagram showing one illustrative embodiment of a cochlear implant system ( 100 ) having a cochlear implant ( 300 ) with an electrode array ( 195 ) that is surgically placed within the patient's auditory system. Ordinarily, sound enters the external ear, or pinna, ( 110 ) and is directed into the auditory canal ( 120 ) where the sound wave vibrates the tympanic membrane ( 130 ). The motion of the tympanic membrane is amplified and transmitted through the ossicular chain ( 140 ), which consists of three bones in the middle ear. The third bone of the ossicular chain ( 140 ), the stirrup ( 145 ), contacts the outer surface of the cochlea ( 150 ) and causes movement of the fluid within the cochlea. Cochlear hair cells respond to the fluid-borne vibration in the cochlea ( 150 ) and trigger neural electrical signals that are conducted from the cochlea to the auditory cortex by the auditory nerve ( 160 ).
As indicated above, the cochlear implant ( 300 ) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing. In many cases, deafness is caused by the absence or destruction of the hair cells in the cochlea, i.e., sensorineural hearing loss. In the absence of properly functioning hair cells, there is no way auditory nerve impulses can be directly generated from ambient sound. Thus, conventional hearing aids, which amplify external sound waves, provide no benefit to persons suffering from complete sensorineural hearing loss.
Unlike hearing aids, the cochlear implant ( 300 ) does not amplify sound, but works by directly stimulating any functioning auditory nerve cells inside the cochlea ( 150 ) with electrical impulses representing the ambient acoustic sound. Cochlear prosthesis typically involves the implantation of electrodes into the cochlea. The cochlear implant operates by direct electrical stimulation of the auditory nerve cells, bypassing the defective cochlear hair cells that normally transduce acoustic energy into electrical energy.
External components ( 200 ) of the cochlear implant system can include a Behind-The-Ear (BTE) unit ( 175 ), which contains the sound processor and has a microphone ( 170 ), a cable ( 177 ), and a transmitter ( 180 ). The microphone ( 170 ) picks up sound from the environment and converts it into electrical impulses. The sound processor within the BTE unit ( 175 ) selectively filters and manipulates the electrical impulses and sends the processed electrical signals through the cable ( 177 ) to the transmitter ( 180 ). The transmitter ( 180 ) receives the processed electrical signals from the processor and transmits them to the implanted antenna ( 187 ) by electromagnetic transmission. In some cochlear implant systems, the transmitter ( 180 ) is held in place by magnetic interaction with the underlying antenna ( 187 ).
The components of the cochlear implant ( 300 ) include an internal processor ( 185 ), an antenna ( 187 ), and a cochlear lead ( 190 ) having an electrode array ( 195 ). The internal processor ( 185 ) and antenna ( 187 ) are secured beneath the user's skin, typically above and behind the pinna ( 110 ). The antenna ( 187 ) receives signals and power from the transmitter ( 180 ). The internal processor ( 185 ) receives these signals and performs one or more operations on the signals to generate modified signals. These modified signals are then sent along a number of delicate wires which pass through the cochlear lead ( 190 ) are individually connected to the electrodes in the electrode array ( 195 ). The electrode array ( 195 ) is implanted within the cochlea ( 150 ) and provides electrical stimulation to the auditory nerve ( 160 ).
The cochlear implant ( 300 ) stimulates different portions of the cochlea ( 150 ) according to the frequencies detected by the microphone ( 170 ), just as a normal functioning ear would experience stimulation at different portions of the cochlea depending on the frequency of sound vibrating the liquid within the cochlea ( 150 ). This allows the brain to interpret the frequency of the sound as if the hair cells of the basilar membrane were functioning properly.
FIG. 2 is an illustrative diagram showing a more detailed view of the external components ( 200 ) of one embodiment of a cochlear implant system. External components ( 200 ) of the cochlear implant system include a BTE unit ( 175 ), which comprises a microphone ( 170 ), an ear hook ( 210 ), a sound processor ( 220 ), and a battery ( 230 ), which may be rechargeable. The microphone ( 170 ) picks up sound from the environment and converts it into electrical impulses. The sound processor ( 220 ) selectively filters and manipulates the electrical impulses and sends the processed electrical signals through a cable ( 177 ) to the transmitter ( 180 ). A number of controls ( 240 , 245 ) adjust the operation of the processor ( 220 ). These controls may include a volume switch ( 240 ) and program selection switch ( 245 ). The transmitter ( 180 ) receives the processed electrical signals from the processor ( 220 ) and transmits these electrical signals and power from the battery ( 230 ) to the cochlear implant by electromagnetic transmission.
FIG. 3 is an illustrative diagram showing one embodiment of a cochlear implant ( 300 ), including an internal processor ( 185 ), an antenna ( 187 ), and a cochlear lead ( 190 ) having an electrode array ( 195 ). The cochlear implant ( 300 ) is surgically implanted such that the electrode array ( 195 ) is internal to the cochlea, as shown in FIG. 1 . The internal processor ( 185 ) and antenna ( 187 ) are secured beneath the user's skin, typically above and behind the pinna ( 110 ), with the cochlear lead ( 190 ) connecting the internal processor ( 185 ) to the electrode array ( 195 ) within the cochlea. As discussed above, the antenna ( 187 ) receives signals from the transmitter ( 180 ) and sends the signals to the internal processor ( 185 ). The internal processor ( 185 ) modifies the signals and passes them along the appropriate wires to activate one or more of the electrodes within the electrode array ( 195 ). This provides the user with sensory input that is a representation of external sound waves sensed by the microphone ( 170 ).
FIG. 4 is a partially cut away perspective view of a cochlea ( 150 ) and shows an illustrative electrode array ( 195 ) being inserted into the cochlea ( 150 ). The primary structure of the cochlea is a hollow, helically coiled, tubular bone, similar to a nautilus shell. The coiled tube is divided through most of its length into three fluid-filled spaces (scalae). The scala vestibuli ( 410 ) is partitioned from the scala media ( 430 ) by Reissner's membrane ( 415 ) and lies superior to it. The scala tympani ( 420 ) is partitioned from the scala media ( 430 ) by the basilar membrane ( 425 ) and lies inferior to it. A typical human cochlea includes approximately two and a half helical turns of its various constituent channels. The cochlear lead ( 190 ) is inserted into one of the scalae, typically the scalae tympani ( 420 ), to bring the individual electrodes into close proximity with the tonotopically organized nerves.
The illustrative cochlear lead ( 190 ) includes a lead body ( 445 ). The lead body ( 445 ) connects the electrode array ( 195 ) to the internal processor ( 185 , FIG. 3 ). A number of wires ( 455 ) pass through the lead body ( 445 ) to bring electrical signals from the internal processor ( 185 , FIG. 3 ) to the electrode array ( 195 ). According to one illustrative embodiment, at the junction of the electrode array ( 195 ) to the lead body ( 445 ) is a molded silicone rubber feature ( 450 ). The feature ( 450 ) can serve a variety of functions, including, but not limited to, providing a structure which can be gripped by an insertion tool, providing a visual indicator of how far the cochlear lead ( 190 ) has been inserted, and securing the electrode array ( 195 ) within the cochlea.
The wires ( 455 ) that conduct electrical signals are connected to the electrodes ( 465 , 470 ) within the electrode array ( 195 ). For example, electrical signals which correspond to a low frequency sound may be communicated via a first wire to an electrode near the tip ( 440 ) of the electrode array ( 195 ). Electrical signals which correspond to a high frequency sound may be communicated by a second wire to an electrode ( 465 ) near the base of the electrode array ( 195 ). According to one illustrative embodiment, there may be one wire ( 455 ) for each electrode ( 610 ) within the electrode array ( 195 ). The internal processor ( 185 , FIG. 3 ) may then control the electrical field generated by each electrode individually. For example, one electrode may be designated as a ground electrode. The remainder of the electrodes may then generate electrical fields which correspond to various frequencies of sound. Additionally or alternatively, adjacent electrodes may be paired, with one electrode serving as a ground and the other electrode being actively driven to produce the desired electrical field.
According to one illustrative embodiment, the wires ( 445 ) and portions of the electrodes ( 470 ) are encased in a flexible body ( 475 ). The flexible body ( 475 ) may be formed from a variety of biocompatible materials, including, but not limited to medical grade silicone rubber. The flexible body ( 475 ) secures and protects the wires ( 455 ) and electrodes ( 465 , 470 ). The flexible body ( 475 ) allows the electrode array ( 195 ) to bend and conform to the geometry of the cochlea.
Management of the wires during the manufacturing process can be challenging. Typically there will be 16 or more small wires which are formed into a bundle. According to one illustrative embodiment, the electrodes are designed to assist in wire management. However, between the end of the lead body ( 445 ) and the first electrode ( 465 ), there is a significant distance where there are no electrodes to assist in the wire management. In some embodiments, a dummy electrode ( 460 ) is inserted midway between the first electrode ( 465 ) and the end of the lead body ( 445 ) to assist in wire management. The dummy electrode ( 460 ) may also serve as a marker which indicates to the surgeon the current depth of insertion. Additionally, a marker rib ( 462 ) may be formed in proximity to the dummy electrode ( 460 ) and may serve as an insertion marker.
According to one illustrative embodiment, the dummy electrode ( 460 ) may assist in wire management by wrapping around the wires and forming a wire bundle. This can prevent the wires from splaying out and contacting other edges or surfaces during the manufacturing process. Damage to the wires can lead to shorts which may degrade the performance of the cochlear implant.
FIG. 5A is a perspective view of one illustrative embodiment of an electrode ( 500 ) which assists in wire management. According to one illustrative embodiment, the electrode ( 500 ) is formed from a platinum or platinum alloy sheet which is cut and bent into the desired shape. To connect a specific wire to the electrode ( 500 ), a flap ( 530 ) is folded over the wire ( 535 ) associated with this electrode ( 500 ) and welded to electrically and mechanically secure it in place. The wings ( 525 ) are folded up to secure the wires for the more distal electrodes and form a bundle of wires which passes back along the electrode array, along the cochlear lead and to the integral processor. The wings ( 525 ) may have a number of features ( 545 , 515 ) which assist in bending the wings or securing the electrode in place. The electrode surface ( 520 ) is on the underside of the electrode ( 500 ). The electrode surface ( 520 ) is not covered by the flexible body and is consequently exposed to the body tissues and fluids within the cochlea. The electrode surface ( 520 ) is used to generate an electrical field through these tissues, thereby stimulating the adjacent auditory nerve.
FIG. 5B is a cross-sectional view of the electrode ( 500 ) shown in FIG. 5A . Cross-sections of the wires ( 535 ) are shown in a wire bundle ( 580 ) contained by the wings ( 525 ). As discussed above, this wire bundle ( 580 ) passes through the entire length of the electrode array ( 195 ); however, each individual wire within the bundle terminated at the electrode to which it is welded.
The management of the wire bundle ( 580 ) has several goals. For example, one goal is to protect the integrity of the wires and their connections to the electrodes. Another goal may be to shape the wire bundle ( 580 ) to influence the overall stiffness of the electrode array ( 195 , FIG. 1 ). Another goal in wire management may be to reduce the manufacturing complexity and cost of the cochlear implant. Additionally, the proper management of the wire bundle can reduce kinking of the lead and incidences of shorts.
FIG. 6A is a side view of an illustrative cochlear lead ( 600 ) which includes an integrated wire carrier ( 605 ). In this illustrative embodiment, the integrated wire carrier ( 605 ) encloses the wires ( 455 ) along a region which extends the location where the wires enter the flexible body ( 475 ) to just before the first electrode ( 465 ). In one illustrative embodiment, the dummy electrode ( 460 ; FIG. 4 ) and marker rib ( 462 ; FIG. 4 ) are no longer needed because of the integrated wire carrier ( 605 ).
According to one illustrative embodiment, the integrated wire carrier ( 605 ) may have a number of marks ( 607 ) which form an insertion depth scale ( 609 ). As the surgeon is inserting the electrode array ( 195 ) into the cochlea, these marks ( 607 ) could be easily visible through the transparent or translucent silicone which makes up the flexible body ( 475 ). The surgeon would then be able to better gauge the depth of insertion or over insertion. For example, a center mark may be the target depth of insertion while marks at the ends of the scale indicate the allowable range of insertion depths. Additionally or alternatively, the scale may allow a surgeon to more precisely personalize the insertion of the electrode into a given cochlea. For example, if a patient has a malformed or partly ossified cochlea, the surgeon may opt not to insert the electrode array as far. The scale ( 609 ) would allow the surgeon to more precisely gauge this customized depth.
The marks ( 607 ) on the scale ( 609 ) may take a variety of forms, colors, thicknesses, and arrangements. According to one illustrative embodiment, the marks on the scale may be formed so that they are visible during X-ray or other non-invasive imaging. The marks ( 607 ) could then be used to gage the accuracy of surgical placement, location of the cochleostomy, or the motion of the electrode over time.
Radio-opaque markers formed on the wire carrier ( 605 ) are one illustrative method for providing visibility of the marks by non-invasive imaging techniques. For example, the radio-opaque markers could be formed from one or more platinum rings which are crimped around the wire carrier ( 605 ). Additionally or alternatively, radio-opaque particles could be incorporated into portions of the wire carrier ( 605 ). For example, tantalum or barium sulfate particles could be incorporated into a silicone rubber wire carrier. In an alternative embodiment, the radio opaque marker could be incorporated directly into the flexible body ( 475 ).
The integrated wire carrier ( 605 ) may have a variety of geometries and be made from a number of different materials. FIGS. 6B-6E are cross-sectional views of illustrative integrated wire carriers ( 605 , 615 , 620 , 625 ) which may be used control, shape, and protect the wire bundle ( 455 ). The integrated wire carriers may be made from a variety of rigid, semi-rigid, or rigid materials, including plastics, metals, composite materials, or other suitable materials. According to on illustrative embodiment, the integrated wire carrier is formed from polytetrafluoroethylene (PTFE), acetal, such as DuPont™ Delrin® acetal resin, polyaryletheretherketone, (PEEK) or silicone.
FIG. 6B is a cross sectional view of one illustrative integrated wire carrier which has a circular cross-section with wires ( 455 ) which pass through the center opening ( 607 ). This design may have a number of advantages including low cost and very good containment of the wires.
FIG. 6C is a cross-sectional view of one illustrative integrated wire carrier which has a circular cross-section with a slit ( 610 ) along one side. The slit ( 610 ) may provide some manufacturing advantages as the wires ( 455 ) do not need to be threaded through the length of the integrated wire carrier ( 615 ). Instead, the wires ( 455 ) or wire bundle can be passed through the slit ( 610 ) and into the center opening ( 607 ). Similarly, FIG. 6D is a cross-sectional view of an illustrative integrated wire carrier ( 620 ) which has a hollow elliptical cross-section. The elliptical cross-section may be useful in forming a wire bundle which is similar to the shape the electrodes will define further down the wire bundle. Additionally, the elliptical integrated wire carrier ( 620 ) may form a wire bundle which has asymmetric bending stiffness which reduces the bending stress as the electrode is inserted around the spiral interior of the cochlea.
FIG. 6E is a cross-sectional view of a “U” shaped integrated wire carrier ( 625 ) which provides containment of the wires ( 455 ) on three sides. This may further simplify the manufacturing process because the integrated wire carrier ( 625 ) may simply be slipped over the wire bundle.
The integrated wire carrier ( 605 , 615 , 620 , 625 ) may have a number of alternative geometries and/or additional features. For example, the composition or wall thickness of the integrated wire carrier may change over its length. Further, the integrated wire carrier may have varying lengths and cover the wires over a different length than that shown in FIG. 6A .
FIG. 7 is a side view of an illustrative cochlear lead ( 190 ) which includes an integrated wire carrier ( 700 ) which follows the wire bundle ( 455 ) as it turns to exit the flexible body ( 475 ). Dashed lines show the path of the wire bundle ( 455 ) through the integrated wire carrier ( 700 ). This extended integrated wire carrier ( 700 ) can provide more comprehensive wire management because the wires will be controlled over almost the entire distance between the exit of the lead body ( 445 ) and the first electrode ( 465 ).
FIG. 8 is a side view of an illustrative cochlear lead ( 190 ) which includes an integrated wire carrier ( 800 ) which extends into the molded feature ( 450 ) and past the first several electrodes ( 465 ). In this illustrative embodiment, the integrated wire carrier ( 800 ) may have a slit which extends over only a portion of its length. For example, the slit may extend from the entry point of the wire bundle to its exit point. The slit may be wide enough to accommodate the protrusion of the electrodes ( 465 , 470 ) to the surface of the flexible body ( 475 ) and to allow for individual electrode wires to be routed and bonded (e.g. welded) to an electrode. Alternatively, the integrated wire carrier ( 800 ) may have a slit along its entire length or other geometry.
The extension of the integrated wire carrier ( 800 ) into the molded feature may have a number of benefits, including better securing the integrated wire carrier into place and better control over the integrated wire carrier during the insertion process.
In sum, an integrated wire carrier can provide wire management within the electrode array. This wire management can shape the wire bundle to reduce the potential for damage to the delicate wires, decrease manufacturing costs, and increase the uniformity of the electrode array. A scale on the exterior of the integrated wire carrier can provide information about the insertion depth of the electrode array during surgery or over time.
The preceding description has been presented only to illustrate and describe embodiments and examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.
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A cochlear lead includes a plurality electrodes forming an electrode array configured to stimulate an auditory nerve from within a cochlea; a lead body connected to the electrode array; a plurality of wires passing through the lead body and connecting to the plurality of electrodes; an integrated wire carrier extending between an exit of the wires from the lead body and a first electrode in the electrode array, the integrated wire carrier comprising a cavity along its longitudinal axis configured to contain the plurality of wires and shape the plurality of wires into a wire bundle in which the plurality of wires passing through the integrated wire carrier are substantially parallel to the longitudinal axis of the integrated wire carrier; and a flexible body encapsulating the integrated wire carrier and the wires.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
Not Applicable
BACKGROUND
1. Technical Field
The present invention generally relates to concrete structures and the methods for forming the same. More particularly, the present invention relates to concrete structures and forming methods that enhance the replenishment of underground water in aquifers.
2. Description of Related Art
As is generally understood, a common source of fresh water for irrigation, human consumption, and other uses is groundwater. Usable groundwater is contained in aquifers, which are subterranean layers of permeable material such as sand and gravel that channel the flow of the groundwater. Other forms of groundwater include soil moisture, frozen soil, immobile water in low permeability bedrock, and deep geothermal water. Among the methods utilized to extract groundwater include drilling wells down to the water table, as well as removing it from springs where an aquifer intersects with the curvature of the surface of the earth.
While groundwater extraction methods are well known, much consideration has not been given to the replenishment thereof. It is not surprising that many aquifers are being overexploited, significantly depleting the supply. The most typical method of aquifer replenishment is through natural means, where precipitation on the land surface is absorbed into the soil and filtered through the earth before reaching the aquifer. However, in arid and semi-arid regions, the supply cannot be renewed as rapidly as it is being withdrawn because the natural process takes years, even centuries, to complete. It is well understood that in its equilibrium state, groundwater in aquifers support some of the weight of the overlying sediments. When aquifers are depressurized or depleted, the overall capacity is decreased, and subsidence may occur. In fact, such subsidence that occurs because of depleted aquifers is partially the reason why some cities, such as New Orleans in the state of Louisiana in the United States, are below sea level. It is well recognized that such low-lying and subsided areas have many attendant public safety and welfare problems, particularly when flooding or other like natural disasters occur.
The problem of rapid depletion is particularly compounded in developed areas such as cities and towns, where roads, buildings, and other man-made structures block the natural absorption of precipitation through permeable soil. Generally, building and paving materials such as concrete and asphalt are not porous, in that water cannot move through the Material and be absorbed into the soil. In fact, porous material would be unsuitable for construction of buildings, where internal moisture is desirably kept to a minimum. Thus, these developed areas are typically engineered with storm drainage systems whereby precipitation is channeled to a central location, marginally cleaned of debris, bacteria, and other elements harmful to the environment which were picked up along the drainage path, and carried out to the sea. Instead of allowing precipitation to absorb into the ground, modern developed areas transport almost all surface water elsewhere.
One of the methods for replenishing aquifers is described in U.S. Pat. No. 6,811,353 to Madison, which teaches a valve assembly for attachment to aquifer replenishment pipes. However, the use of such replenishment systems required frequent human intervention. Furthermore, in order for the water in the aquifer to remain clean, existing clean water had to be pumped in. Additionally, the volume of water that was able to be carried to these re-charging locations was limited, thus limiting the replenishment capacity.
Changes to paving materials have also been considered. As is well known in the art, concrete is a composite material made from aggregate and a cement binder, the most common form of concrete being Portland cement concrete. The mixture is fluid in form before curing, and after pouring, the cement begins to hydrate and gluing the other components together, resulting in a relatively impermeable stone-like material. By eliminating the aggregate of gravel and sand, the concrete formed miniature holes upon curing, resulting in porous concrete. This form of concrete, while allowing limited amounts of water to pass through, was unsuitable for paving purposes because of its reduced strength. Additionally, the aforementioned drainage systems were still required because the porous concrete was unable to handle all of the water in a typical rainfall. Structures designed to increase the strength while maintaining porosity have been attempted, whereby reinforcement in the form of rods, rebar, and/or fibers were incorporated into the structure. Nevertheless, the strength of the structure was insufficient because of the reduced internal bonding force of the concrete due to the lack of an aggregate.
Therefore, there is a need in the art for an aquifer replenishment system for collecting precipitation and absorbing the same into the pavement and the soil in the immediate vicinity. There is also a need for aquifer replenishment system that are capable of withstanding environmental stresses such as changes in temperature, as well as structural stresses such as those associated with vehicle travel. Furthermore, there is a need for an aquifer replenishment system that can be retrofitted into existing pavement structures.
BRIEF SUMMARY
In light of the foregoing problems and limitations, the present invention was conceived. In accordance with one embodiment of the present invention, an aquifer replenishing pavement is provided, which lies above soil having a sand lens above an aquifer, and a clay layer above the sand lens. The structure is comprised of: an aggregate leach field abutting the subgrade (typically comprised of clay); and a layer of suitable surface paving material such as reinforced concrete or asphalt, abutting the aggregate leach field. Additionally, one or more surface drains extend through the concrete layer, and one or more aggregate drains extend from the aggregate leach field to the sand lens. The surface drains have a higher porosity than the paving layer, and is filled with rocks. According to another aspect of the invention, leach lines having a higher porosity than the surrounding leach field are provided. The surface drains are in direct fluid communication with the leach lines, and the leach lines are in direct fluid communication with the aggregate drains.
An aquifer replenishing concrete paving method is also provided, comprising the steps of: (a) clearing and removing a top soil layer until reaching a clay layer; (b) forming one or more aggregate drains through the clay layer to a sand lens; (c) forming an aggregate leach field above the clay layer; (d) forming a pavement layer above the aggregate leach field; and (e) forming surface drains extending the entire height of the pavement layer. Additionally, forming of the aggregate leach field also includes the step of forming one or more leach lines therein.
In accordance with another embodiment of the present invention, an aquifer replenishing concrete gutter for use on a road surface with an elevated curb section is provided. The gutter is comprised of a porous concrete section having an exposed top surface in a co-planar relationship with the road surface, supported by the elevated curb section and the side surface of the road. According to another aspect of the present invention, a cut-off wall is provided to further support the porous concrete section. A bore extending from the porous concrete down to the aquifer is also provided, and is filled with rocks.
An aquifer replenishing concrete gutter formation method is provided, comprising the steps of: (a) forming a gutter section between an elevated curb section and a road surface; (b) boring a hole in the gutter section into the aquifer; (c) filling the hole with rocks; (d) filling the gutter section with porous concrete; and (e) curing the porous concrete. In accordance with another aspect of the present invention, step (a) includes removing a section of the road surface adjacent to the elevated curb section. Finally, step (a) also includes forming a cut off wall extending downwards from the road surface and offset from the elevated curb section.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
FIG. 1 is a cross-sectional view of the surface of the earth;
FIG. 2 is a perspective cross-sectional view of a road surface aquifer replenishment system in accordance with an aspect of the present invention;
FIG. 3 is a cross-sectional view of a gutter aquifer replenishment system in accordance with an aspect of the present invention;
FIG. 4 is a cross-sectional view of a conventional road;
FIG. 5 is a cross-sectional view of a conventional road excavated for retrofitting an aquifer replenishment system in accordance with an aspect of the present invention;
FIG. 6 is a cross-sectional view of conventional road after excavation and formation of a cut-off wall in accordance with an aspect of the present invention; and
FIG. 7 is a cross sectional view of a road after excavating a bore reaching an aquifer and filling the same with rocks, and depicts the pouring of concrete into the gutter section in accordance with an aspect of the present invention.
DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. It is to be understood, however, that the same or equivalent functions may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.
With reference now to FIG. 1 , a cross sectional view of the earth's surface is shown. Atmosphere 30 is shown with clouds 32 releasing precipitation 34 , falling towards the ground 50 . As is well understood, ground 50 is comprised of top soil layer 52 . Underneath top soil layer 52 is clay layer 54 , and underneath that is sand lens 56 . Aquifer 60 is a layer of water, and can exist in permeable rock, permeable mixtures of gravel, and/or sand, or fractured rock 58 . Precipitation 34 falls on top soil layer 52 , and is gradually filtered of impurities by the varying layers of sand, soil, rocks, gravel, and clay as it moves through the same by gravitational force, eventually reaching aquifer 60 . In the context of the above natural features, the present invention will be described.
Referring now to FIG. 2 , a first embodiment of the present inventive concrete paving system 100 is shown. Situated above clay layer 54 is an aggregate leach field 82 comprised of sand and gravel particles. Above aggregate leach field 82 is a pavement layer 80 , which by way of example only and not of limitation, is concrete composed of Portland cement and an aggregate. Pavement layer 80 may be reinforced with any reinforcement structures known in the art such as rebar, rods and so forth for increased strength. Preferably, the reinforcement structure has the same coefficient of thermal expansion as the pavement material, for example, steel, where concrete is utilized, to prevent internal stresses in increased temperature environments. By way of example only and not of limitation, pavement layer 80 has reinforcement bars 90 . It will be appreciated by one of ordinary skill in the art that the pavement layer 80 need not be limited to architectural concrete, and asphalt and other pavement materials may be readily substituted without departing from the scope of the present invention.
Extending from the top surface to the bottom surface of pavement layer 80 are one or more surface drains 84 . Due to the fact that non-porous concrete, that is, concrete having aggregate mixed into the cement, permits little water to seep through, surface drains 84 expedite the water flow into aggregate leach field 82 . Typically, by way of example only and not of limitation, surface drains 84 are filled with rocks to prevent large debris such as leaves and trash from clogging the same.
Within aggregate leach field 82 are one or more leach lines 86 , which assist the transfer of fluids arriving through surface drains 84 . By way of example only, leach lines 86 are in direct fluid communication with surface drains 84 . Leach lines 86 have a higher porosity than the surrounding leach field 82 to enable faster transmission of fluids. Leach field 82 is also capable of absorbing water, and in fact, certain amounts are absorbed from leach lines 86 . Additional water flowing from surface drains 84 is also absorbed into leach field 82 . In this fashion, water is distributed across the entire surface area of leach field 82 , resulting in greater replenishment of the aquifer. A person of ordinary skill in the art will recognize that the leach field 82 acts as a filter by gradually removing particulates from precipitation, and resulting in cleaner water in the aquifer.
As is well understood in the art, clay has a lower porosity as compared to an aggregate of, for example, sand, gravel, or soil. In order to expedite the transmission of water into the aquifer, aggregate drains 88 extend from aggregate leach field 82 , through clay layer 54 , and into sand lens 56 . Therefore, a minimal amount of water is absorbed into the clay layer 54 , and the replenishment process is expedited.
After the water flows from leach field 82 into sand lens 56 via aggregate drains 88 , it is dispersed throughout sand lens 56 , trickling through to the aquifers in the vicinity. The water in the aquifer is thus replenished through largely natural means, namely the filtration process involved in absorbing precipitation through aggregate leach field 82 and sand lens 56 , despite the existence of a non-porous material such as concrete overlying the ground surface in the form of pavement layer 80 .
The aquifer replenishment system as described above is generally formed over previously undeveloped land, or any land that has been excavated to a clay layer 54 . Thus, surfaces that have been previously paved by other means must first be removed so that the natural water absorption mechanisms of the earth are exposed. After this has been completed, aggregate drains 88 are drilled from the exposed clay surface 54 into sand lens 56 . After filling the aggregate drains 88 with aggregate, a generally planar aggregate leach field 82 is formed. Contemporaneously, leach lines 86 are formed, and is encapsulated by the aggregate which constitutes leach field 82 . After leach field 82 is constructed, concrete reinforcements 90 are placed, and uncured concrete is poured to create pavement layer 80 .
With respect to the formation of surface drains 84 , any conventionally known methods of creating generally cylindrical openings in concrete may be employed. For example, before pouring the uncured concrete, hollow cylinders may be placed and inserted slightly into leach field 82 to prevent the concrete from flowing into the opening. Yet another example is pouring the concrete and forming a continuous layer, and drilling the concrete after curing to form surface drain 84 . It is to be understood that any method of forming surface drain 84 is contemplated as within the scope of the present invention.
With reference to FIG. 3 , a second embodiment of the aquifer replenishing system 200 is shown, including an elevated curb section 192 , a gutter section 196 , and a road pavement section 190 . Road pavement section 190 is comprised of a pavement surface 195 , which by way of example only and not of limitation, is architectural concrete, asphalt concrete, or any other paving material known in the art, and is supported by base course 194 . Base course 194 is generally comprised of larger grade aggregate, which is spread and compacted to provide a stable base. The aggregate used is typically ¾ inches in size, but can vary between ¾ inches and dust-size.
In accordance with the present invention, gutter section 196 has a porous concrete gutter 184 in which the top surface thereof is in a substantially co-planar relationship with the top surface of pavement surface 195 . Optionally, porous concrete gutter 184 is supported by base 185 which is composed of similar aggregate material as base course 194 . Furthermore, extending from optional base 185 into aquifer 60 is a rock filled bore 188 . As a person of ordinary skill in the art will recognize, a bore filled with rocks will improve the channeling of water due to its increased porosity as compared with ordinary soil. Optional base 185 and porous concrete gutter 184 is laterally reinforced by cut off walls 183 and elevated curb section 192 . The cut off walls 183 are disposed on opposing sides of the porous concrete gutter 184 and the base 185 between the elevated curve section 192 and the pavement surface 195 . It is expressly contemplated that the cut off walls 183 may be pre-cast or cast in place.
When precipitation falls upon road pavement section 190 , the water is channeled toward gutter section 196 . Porous concrete gutter 184 permits the precipitation to trickle down to aquifer 60 . When optional base 185 and rock filled bore 188 is in place, there is an additional filter effect supplementing that of the porous concrete gutter 184 . A similar result can be materialized where the water drains from the upper surface of elevated curb section 192 , or precipitation directly falls upon porous concrete gutter 184 . Please note a large surface drain may be used in lieu of the porous concrete gutter.
This embodiment is particularly beneficial where retrofitting the gutter is a more desirable solution rather than re-paving the entire road surface. In a conventional road pavement as shown in FIG. 4 , pavement surface 195 and base course 194 extend to abut elevated curb section 192 . In preparation for retrofitting gutter section 196 , a section of pavement surface 195 and base course 194 is excavated as shown in FIG. 5 , leaving a hole 197 defined by the exposed surfaces of elevated curb section 192 , base course 194 , and pavement surface 195 . This is followed by the optional step of pouring and curing a cut-off wall 183 as illustrated in FIG. 6 , which, as discussed above, serves to reinforce the gutter section 196 . One or more bores 188 are drilled down to aquifer 60 , and filled with rocks, as shown in FIG. 7 . An optional base of aggregate 185 is formed above rock filled bore 188 , and compacted by any one of well recognized techniques in the art. Finally, a volume of porous concrete mixture, that is, a concrete without sand or other aggregate material, is poured and cured, forming porous concrete gutter 184 . While recognizing the disadvantages of using porous concrete, namely, the reduced strength of the resultant structure, a person of ordinary skill in the art will also recognize that gutter section 196 sustains less stress thereupon in normal use as compared to road pavement section 190 .
The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.
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A concrete structure for replenishing an aquifer and a method for constructing the same is provided. The structure is comprised of a pavement layer with surface drains that extend through the pavement layer and into an aggregate leach field. The leach field includes leach lines spanning the leach field. An aggregate drain extends from the leach field into a sand lens. Precipitation which falls upon the structure thus flows through the surface drain, absorbed into the aggregate leach field, and transported to the aggregate drains by way of aggregate leach lines. The water is then absorbed into the sand lens, ultimately replenishing the aquifer. Existing conventional pavement structures are retrofitted by the removal of a section of the pavement, and filling the same with porous concrete.
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RELATING APPLICATION
This application is a continuation in part of application, Ser. No. 377,368, file July 30, 1982 which is hereby incorporated by reference (now abandoned), and which is the parent application of Ser. No. 738,544 filed May 28, 1985 (now U.S. Pat. No. 4,707,995).
TECHNICAL FIELD
This invention relates to a method of and means for controlling the condition of air in an enclosure, and more particularly for controlling the temperature and humidity of air in an enclosure such as a greenhouse.
BACKGROUND OF THE INVENTION
Agricultural products, such as vegetables and flowers, are grown on a large scale in greenhouses throughout the world. During daylight hours, growing agricultural products introduce water vapor into the greenhouse and extract carbon dioxide from the air. The growth of such products is enhanced when excess carbon dioxide is introduced into the greenhouse during daylight hours. This can be accomplished, particularly if heat is needed during the day, by burning LP or natural gas and passing the products of combustion directly into the greenhouse. Water heated by burning the fuel can be stored during the day to provide a reservoir of heat that can be released during the night time to heat the greenhouse. The primary deficiency of this approach is the water vapor contained in the flue gases. When this water vapor is added to the water vapor produced by the the growing agricultural products, saturated or nearly saturated conditions are created within the greenhouse. This condition of high humidity produces undesirable stress on all but tropical plants, and increases susceptibility the plants to various diseases which require periodic spraying or other treatment. As a consequence, considerable resistance thas been encountered in applying this approach to greenhouse management.
It is therefore an object of the present invention to provide a new and improved method of and apparatus for controlling the condition of air in an enclosure such as a greenhouse, where the disadvantages of the prior art are substantially overcome or reduced.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, the air in a greenhouse is dehumidified using a direct-contact heat exchanger utilizing concentrated brine. The diluted brine produced when water vapor in the greenhouse condenses on the concentrated brine is regenerated in a fuel-fired boiler whose products of combustion are passed into the greenhouse. The products of combustion provide the desired level of carbon dioxide in the greenhouse; and the excess water vapor in the products of combustion as well as a significant portion of the water vapor produced by the plants growing in the greenhouse are removed by the hygroscopic concentrated brine. Thus the relative humidity of the air in the greenhouse can be closely controlled by controlling the concentration of the brine, the size of the direct-contact heat exchanger, and the mass flow of air passing over the heat exchanger.
The heating of the diluted brine in the boiler produces steam that is available to heat the interior of the greenhouse, if this is necessary; or the steam can be used for other purposes. Thus, the steam, as it is produced, can be piped directly to a closed heat exchanger within the greenhouse to warm the air therein; or the steam can be condensed to provide fresh water if the greenhouse is in an arid climate. Alternatively, the steam can be piped to a heat storage tank to provide hot water that can be circulated into a heat exchanger in the greenhouse during the night if, heat is needed only at night. Preferably, a heat exchanger is provided by which the concentrated brine produced by the boiler is tranfered to the diluted brine before it enters the boiler.
DESCRIPTION OF DRAWINGS
Embodiments of the invention are shown in the accompanying drawings wherein:
FIG. 1 is a schematic block diagram illustrating the method of and apparatus for controlling the condition of air in a greenhouse in accordance with present invention; and
FIG. 2 is a schematic block diagram of an alternative arrangement for removing water vapor from a greenhouse and heating the greenhouse using a brine dehumidifier.
DETAILED DESCRIPTION
Referring now to the drawing, reference numeral 10 designates a greenhouse containing agricultural products 12 that absorb carbon dioxide during daylight hours and produce water vapor. At night, products 12 are quiescent. Associated with greenhouse 10 is apparatus 14 according to the present invention. Apparatus 14 comprises direct-contact brine dehumidifier 16 to which concentrated brine is supplied by a conduit 18 from brine reservoir 20, and from which diluted brine is obtained by conduit 22. Dehumidifier 16 comprises a felt pad or mate of jute material that provides a large surface area over which the concentrated brine is fed to form a thin film of brine exposed to the air. Thus, dehumidifier 16 operates as a thin film, direct-contact heat exchanger as described below.
Duct 24 contained within greenhouse 10, and within which brine dehumidifier 16 is located, provides means for recirculating air in the greenhouse through the dehumidifier. Specifically, duct 24 contains fan 26 which draws humid air in the greenhouse through the dehumidifier and causes the air to pass through heat exchanger or radiator 28 before the air is reintroduced into the greenhouse.
Boiler 30, associated with brine reservoir 20 is heated by fuel burned in burner 32 which is connected to source 34 of fuel. Diluted brine from conduit 22 is pumped, or flows by gravity, through counter-flow heat exchanger 36 and enters boiler 30 where it is regenerated by being heated. The boiler concentrates the diluted brine by evaporating water therefrom producing steam. Conduit 38 carries the steam to valve 40 which selectively directs the steam into radiator 28 (if the greenhouse must be heated), or into water tank 42 when the heat in the steam must be stored for use at a later time.
Boiler 30 thus concentrates the diluted brine; and the concentrated brine passes through heat exchanger 36 into brine reservoir 20. The hot, concentrated brine produced by the boiler is cooled in heat exchanger 36 before being delivered to brine reservoir 20; and heat extracted from the concentrated brine is transfered to the incoming diluted brine.
Preferably, the fuel burned in burner 32 is liquified petroleum gas or natural gas in order to limit the products of combustion to carbon dioxide and water vapor. The products of combustion produced by the burned fuel associated with burner 30 are piped by a ductwork 44 into greenhouse 10 such that the products of combustion, namely carbon dioxide and water, are transfered into the greenhouse.
During daylight hours, when the agricultural products such as flowers or vegetables are growing, they actively absorb carbon dioxide in the air in the greenhouse. The active agricultural products also give off water vapor which adds to the water vapor introduced into the greenhouse by the products of combustion. In the absence of steps to the contrary, an almost saturated condition will result; and the purpose of brine dehumidifier 16 is to dehumidify the air within the grenhouse. Additionally, dehumidifier 16 serves to increase the temperature of the air in the greenhouse in a manner explained below. Effectively, dehumidifier 16 is designed to maintain a humidity within the greenhouse at a level below 85%, and preferably between 80 and 85%. As explained below, the humidity of the air will be a function of the concentration of brine in the dehumidifier, the effective area of the brine dehumidifier and the mass flow therethrough.
If it is desirable, steam from boiler 30 can be introduced into heat exchanger 28 for purposes of further increasing the temperature in the air and in the greenhouse, or valve 40 can be selectively operated to direct the steam into water tank 42. At night, when excess carbon dioxide is not needed in the greenhouse, the operation of boiler 30 can be suspended; and the heat stored in water tank 42 as a consequence of daytime operation of the boiler to produce carbon dioxide. Alternatively, the steam produced by the boiler can be directed into a network of pipes buried in the ground beneath the greenhouse thus storing the heat in the ground. When the greenhouse is based on hydrophonic operation, the steam produced by the boiler can be used to heat the liquids that are used in the hydrophonic process.
Dehumidifier 16 may be conventional in sense that it is a direct contact heat exchanger in which concentrated brine is applied to a felt, jute or paper mat as a thin film.
Alternatively, the mat may be a capillary web through which the brine flows slowly. The vapor pressure of concentrated brine is small as compared with the saturated vapor pressure of water at the same temperature. When concentrated brine is exposed to the air in the greenhouse, water vapor in the air condensers on the brine. The latent of condensation supplied to the brine during evaporation of water vapor heats the brine film; and the heated brine transfers its heat to the air flowing over the brine. This is an isentropic process in which the temperature of the brine remains substantially constant as the air is warmed and dried in passing through the dehumidifier.
If the temperature in the greenhouse during the day is 27 deg. C., and if the brine temperature is about 30 deg. C both entering and leaving the dehumidifier, a flow rate of about 1.5 cu.m per hour per 1000 sq.m of a greenhouse would be required in order to maintain a rate of humidity of about 84% within the greenhouse. This arrangement provides about about 200 kWh per 1000 sq.m. of greenhouse area of heating during daylight hours assuming that the brine concentration changes from about 50% concentration to about 30% concentration within the dehumidifier. At night, the flow rate of the brine can be reduced to a level that just keeps the mat wet. This would provide additional dehumidification at night. To obtain the high concentration brine, calcium chloride is the preferred salt; but other salts such as magnesium or mixtures of salts can be used. Dead Sea and brine can also be used. The fuel required to regenerate the brine and provide carbon dioxide during the day would be about 10 kg/1000 sq.m. of greenhouse area which will provide about 10 hours of operation per day. In some environments, the operation can be carried out only for 3 to 4 hours during the day because the temperature within the greenhouse will become excessive so far as the agricultural products are concerned. This requires either the shutdown of the system or the introduction of outside air into the greenhouse.
To provide suitable control over the operation of the system shown in FIG. 1, duct 44 may be provided with an adjustable butterfly valve 48 for controlling the rate in which the products of combustion are admitted into greenhouse 10 and a suitable valve (not shown) may be provided in duct 24 and in the greenhouse itself for purpose of controlling the flow air into the duct and into the greenhouse respectively.
The present invention is also usable in drying agricultural product, such as tobacco. In such case, the products of combustion are discharged directly to the atmosphere bypassing the enclosure. The heat in the steam produced during regeneration of the brine can be saved and used for drying the agricultural products--or used by the consumer. For example, if the drier requires a temperature of 73 deg C. and a humidity of 77%, the dehumidifier can deliver air at 88 deg C. with a humidity of 25%. To achieve this, the temperature of the concentrated brine entering the dehumidifier should be about 92 deg C. The vapor pressure of brine of density 1.5 at this temperature is only about 20% of the vapor pressure of water at this temperature, An airflow rate of only about 1 kg/sec of air will remove vapor at the rate of 7 gm/sec or 15 KW of heat.
FIG. 2 is an embodiment of the invention by which a brine dehumidifier according to the present invention is used to dehumidify the air in a greenhouse and to extract and store sensible heat from the air during the day, and to give back the sensible heat to the air during the night for the purpose of heating the greenhouse. In this embodiment, regeneration of the brine is achieved on an annual basis using solar energy rather than a boiler.
Reference numeral 50 designates a greenhouse containing agricultural products 52 that produce water vapor during the day as indicated previously. Duct 54 contains brine dehumidifier 56 through which air in the greenhouse is recirculated by reason of the operation of fan 58. Dehumidifier 56 is similar to dehumidifier 16 in the sense that concentrated brine contained in a reservoir 60 is applied to the dehumidifier such that the brine and humid air come into direct contact. By reason of the hygroscopic nature of brine, water vapor in the air in the greenhouse condenses on the brine diluting the same.
During daylight hours when the temperature within the greenhouse is some 10 deg. C. higher than the temperature at night, a considerable amount of sensible heat contained in the air in the greenhouse is absorbed by the brine which increases in temperature. At the same time, the brine also absorbs the latent heat of condensation of the water vapor contained in the air. For example, if the temperature within the greenhouse during the day is about 27 deg. C. and the brine temperature at the inlet is about 25 deg. C., a 5 deg. C. increase in the brine temperature to about 30 deg. C. can occur. With a flow rate of about 30 cu.m./h per 1000 sp.m. of greenhouse area, about 1200 kWh of heat will be removed from the air and stored in the brine. The heated, diluted brine is delivered to reservoir 60.
At night, when the temperature of the greenhouse drops by about 10 deg. C., the temperature of the concentrated brine entering the dehumidifier will be about 30 deg. C.; and in this case, the sensible heat from the brine is transfered to the air which is thus heated. About 5 deg. C. temperature drop of the brine will occur; and diluted brine, at about 25 deg. C. is delivered to reservoir 60. Thus, at night, the brine will give up about the same amount of heat as was absorbed during the day.
During the beginning of the winter season, the concentration of the brine may be about 50%. After the winter season it would be diluted to about 30%. This difference in salinity represents the latent heat of condensation made available for heating during nights of the winter; and this heat must be restored to the brine in order to regenerate it. Regeneration is achieved during the summer. Reservoir 60 acts as an evaporator wherein the water vapor accumulated during the winter evaporates thereby concentrating the brine.
The advantages and improved results furnished by the methods and apparatus of the present invention are apparent from the foregoing description of the various embodiments of the invention. Various changes and modifications may be made without parting from the spirit and scope of the invention as described in the claims that follow.
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The air in a greenhouse is dehumidified using a direct-contact heat exchanger utilizing concentrated brine. The diluted brine produced when water vapor in the greenhouse condenses on the concentrated brine is regenerated in a fuel-fired boiler whose products of combustion, carbon dioxide and water vapor, are passed into the greenhouse. The products of combustion provide the desired level of carbon dioxide in the greenhouse; and the excess water vapor in the products of combustion as well as a significant portion of the water vapor produced by plants, growing in the greenhouse are removed by the hygroscopic concentrated brine.
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The government has rights in this invention pursuant to Grant Number DE-FG02-85ER45176.
The United States Government retains rights to this invention based upon funding by the Department of Energy under Contract DE-FG02-85ER-45176.
BACKGROUND OF THE INVENTION
This invention relates to press coating and oxidation of metallic precursor alloy synthesis methods for high T c superconducting materials.
Bulk, high T c superconducting oxides suitable for power transmission applications have been synthesized with a number of processing techniques. These techniques include high temperature oxidation of metallic precursor alloys containing metallic constituents of desired superconducting oxides. Such metallic precursors can be made by any metal forming technique depending upon the required superconductor shape including melt spinning, planar flow casting, melt dipping and melt writing. Metallic precursors can contain metals stable through oxidation processing including noble metals such as silver to produce superconducting oxide/metal microcomposites with combined good mechanical and superconducting electrical properties.
SUMMARY OF THE INVENTION
According to one aspect of the invention, high T c oxide superconductor composites are synthesized by pressure coating a substrate with oxidized metallic precursor alloy.
As an example of the invention, a Bi--Pb--Sr--Ca--Cu--O superconductor composite is synthesized by pressure coating a substrate with an oxidized Bi--Pb--Sr--Ca--Cu/noble metal precursor alloy to produce the Bi--Pb--Sr--Ca--Cu--O/noble metal superconductor composite. Other superconducting systems including Yb--Ba--Cu--O, Y--Ba--Cu--O, and Tl--Ba--Ca--Cu--O can be processed with the press coating method.
In some embodiments, the metallic precursor alloy can be prepared using any metals processing technique including melt spinning, melt dipping, and melt writing. The oxidized metallic precursor alloy can be pressed or rolled onto the substrate at temperatures between 25° C.-800° C. and pressures between 1 and 20 MPa. Substrate materials can be pure metals such as Ag, Au, Pt, Pd, Cu or Ni; stainless steel and nickel alloys; composites including Ag sheets on stainless steel and Ag sheets on Fe, Co, Cu, and Ni alloys, and metal/ceramic composites and ceramics. The Bi--Pb--Sr--Ca--Cu metallic precursor can contain surplus Ca or Cu.
In other embodiments, multiple layers whose thickness and width are controlled by adjusting processing conditions, can be applied to a substrate. Superconducting properties can be optimized by design of suitable heat treatments and multiple press/anneal sequence repetition. Selected mechanical deformation and atmospheric conditions can be combined to enhance superconductor texturing.
In other embodiments, the method can be used to produce high T c superconductor coatings in a variety of geometries including large or small areas with flat, smooth surfaces and uniform thickness, long wires, and ribbons of selected thickness. Protective coatings can be pressed or rolled onto superconductor coatings using this technique.
Press coating can be used in combination with other superconductor preparation techniques including melt dipping and melt writing methods to further enhance superconducting and mechanical properties. Press coating can be used to join superconductors or fabricate superconductor/normal metal joints. Press coating can also be used in combination with superconducting oxides prepared by other fabrication techniques including powder processing of the individual metal oxides and pyrolysis of metal-organo precursors.
Compared with conventional ceramic processes or the simple metallic precursor oxidation method, the present method offers several advantages. The pressing or rolling treatment produces a dense superconductor coating. The resulting composite has good mechanical properties based on substrate strength and toughness combined with good adhesion between coating and substrate. Combined mechanical deformation and controlled atmosphere annealing produces textured microstructures, characterized by increased critical current density. This method offers considerable flexibility in fabrication of varied geometry composites including wire, narrow or wide ribbon, and small or large area coatings. Coating thickness is uniform (typically 5-200 μm), and can be accurately controlled by the pressing or rolling process.
The product of the oxidation and press coating method is typified by having a textured microstructure with platelike grains of superconductor phase aligned parallel to the substrate plane. The superconductor composite contains no gap between the coating and the substrate.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic illustration of the press coating process;
FIG. 2 is a schematic illustration of the press coating of a multi-layered superconductor composite;
FIG. 3 is an SEM backscattered electron (BSE) micrograph from a polished, longitudinal cross-section of multi-layered Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 21 ribbon pressed on a Ag substrate after suitable oxidation and annealing;
FIG. 4 is an SEM backscattered electron (BSE) micrograph from a polished longitudinal cross-section of a multi-layered Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 21 ribbon pressed on a Au substrate after suitable oxidation and annealing;
FIG. 5 is an SEM (BSE) cross-section micrograph for an oxidized Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 5 alloy press-coated onto a Ag substrate after suitable oxidation and annealing;
FIG. 6 is an SEM (BSE) cross-section micrograph for a Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 11 alloy press-coated onto a Ag substrate after suitable oxidation and annealing;
FIG. 7 is an SEM (BSE) micrograph for a Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 36 alloy pressed on a Ag substrate after suitable annealing; and
FIG. 8 is an SEM (BSE) micrograph for Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 21 alloy pressed on a Ag substrate after suitable oxidation and repeated pressing and annealing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In a preferred embodiment, Bi--Pb--Sr--Ca--Cu--O/Ag microcomposites were fabricated on Ag, Au, Cu, Pt, Pd, Ni and silver sheet covered stainless steel substrates.
Precursor alloy ribbons were produced by vacuum melting and melt spinning rapid solidification of alloys with nominal compositions (atomic proportions) 1.4 Bi--0.6 Pb--2 Sr--3 Ca--4 Cu with 5, 11, 21 and 36 Ag, corresponding to 35-80 wt. % Ag. Surplus Ca and Cu in the alloys is necessary for obtaining a well developed "2223" superconducting phase. Ribbon thickness and width ranged typically from 50-70 μm and 2 to 3 mm respectively. Ribbons were fully oxidized at 500°-600° C. in 100% O 2 for 40 h and annealed at 820° C. in 5% O 2 +95% Ar for 8 h prior to press coating. Pure Ag sheets (≧99.9% Ag) 0.025-0.25 mm thick, Au, Pt, Pd, Ni, Cu sheets 0.051 mm thick, and stainless steel plates (≃0.3 mm) covered by 0.025 mm thick Ag sheet were used as substrates. Metallic substrates were used as received without further polishing. Substrates were cleaned with dry methanol and distilled water.
Press coating was conducted in a PR-22 Pneumatic Mounting Press under 2-10 MPa pressure at 160° C. Substrates of approximately 3×10 mm dimensions and ribbon were positioned between two steel dies. FIG. 1 shows one piece of ribbon 30 being pressed as indicated by arrow 31 on substrate 32 by dies 34. Alternately, substrates 10 and five layers of ribbon 12, 14, 15, 16, and 18 were positioned between dies 20 with or without lubricating teflon films 22 as shown in FIG. 2. Pressure was applied slowly in the direction given by arrow 24, held for at least 4 minutes, and released.
Press-coated layers were flat, with smooth, shiny surfaces and uniform thicknesses. The degree of adhesion between coating and substrates depends upon substrate properties, applied pressure and processing temperature. Substrate/coating adhesion has been qualitatively classified by visual inspection after cooling, heat treatment and slow bending to approximately 20 degree angles.
Coatings on Ag substrates exhibited the best adhesion, followed by those on Au, Cu and Pd substrates. Coating adhesion on Ag and Au was satisfactory, without spalling or delamination even after subsequent annealing, cooling and bending to 20 degrees. Coatings on Pt, Ni and 304 stainless steel were not adherent. Coatings on Pt, Ni or stainless steels were made adherent by pressing two substrate sheets with teflon films on both sides of the coatings, as shown in FIG. 2.
Pressing caused coating and substrate deformation. The extent of deformation depended on applied pressure, coating and substrate materials, processing temperature and lubrication. A thickness reduction ratio R was used to describe the deformation, as
R=t.sub.2 /t.sub.1
where t 1 and t 2 are the coating thickness before and after pressing, respectively. Table I shows thickness reduction ratio R, applied pressure, coating and substrate materials, and adhesion behavior of coated layers.
As shown in Table I, ratios R vary from 0.30 to 0.45 for Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 21 coatings on different substrates subject to identical pressing conditions of 8 MPa without lubrication. Deformation decreased in order for Au, Ag, Cu, Pd, Pt and Ni substrates consistent with the different hardness, ductility and contact friction characteristic of these metals. Lubricant teflon films reduced contact friction and increased deformation by 30-40%, and made behavior of different substrates more uniform.
Adhesion and deformation of coatings also depended on applied pressure. A ≧4 MPa pressure was needed for good coating adhesion on Ag, while pressure ≧10 MPa caused large deformation and sample edge cracking. Coating material composition did not affect the deformation ratio significantly. Coatings with different Ag concentrations exhibited similar thickness after pressing, as shown in Table I.
Press-coated specimens required a second anneal to ensure good superconducting properties. Such anneals removed microcracks created by press/deformation processes which interrupt superconducting grain continuity and adversely affect superconducting properties. Anneals were conducted in 5% O 2 +95% Ar atmospheres. Deformation processing and annealing were combined to optimize superconducting properties. Resulting superconducting onset temperature, T on , zero resistance temperature, T R ═O, and critical current density, J c , at 77K in zero field are listed in Table II, together with sample pressing and annealing conditions.
T c and J c were measured using a standard four-point probe technique. In J c (77) measurements, a criterion of 1 μv/cm was used to define the critical current I c and the entire coating cross section was used to calculate the critical current density J c (77) Special attention was given to current passing through the Ag substrate since Ag is an excellent electrical conductor. At 77K, a pure Ag substrate showed a linear plot of voltage versus current at a scale of 1 mA, with a slope of order 0.1-1 μV/mA, while a superconducting coating on a Ag substrate did not show any voltage until the current reached I c (approximately 1A), when a sharp transition occurred. Hence, it follows that I c measurements were not significantly affected by the Ag substrates.
TABLE I__________________________________________________________________________Deformation Ratio and Pressed Coating Quality Applied DeformationCoating Substrate & Pressure Ratio Surface QualityMaterial Lubricant (MPa) R(= t.sub.2 /t.sub.1).sup.*1 & Adhesion.sup.*2__________________________________________________________________________Bi.sub.1.4 Pb.sub.0.6 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ag.sub.21 Ag/NL.sup.*3 8 0.35 adhesion good600C/48h + 820/8h smooth surface Au/NL 8 0.30 adhesion good smooth surface Cu/NL 8 0.36 adhesion fair smooth surface Pd/NL 8 0.38 adhesion fair smooth surface Pt/NL 8 0.42 no adhesion Ni/NL 8 0.45 no adhesionAs above Ag/TF.sup.*4 8 0.24 adhesion good smooth surface Cu/TF 8 0.25 edge cracking Ni/TF 8 0.27 smooth surfaceAs above Ag/NL 2 0.80 barely adhered Ag/NL 4 0.70 adhesion fair smooth surface Ag/NL 6 0.40 adhesion good smooth surface Ag/NL 10 0.32 adhesion good smooth surface edge crackingBi.sub. 1.4 Pt.sub.0.6 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ag.sub.3 Ag/NL 8 0.33 adhesion fair400C/48h + 820/8h surface roughnessBi.sub.1.4 Pb.sub.0.6 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ag.sub.11 Ag/NL 8 0.35 adhesion fair600C/48h + 820/8h smooth surfaceBi.sub.1.4 Pb.sub.0.6 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ag.sub.36 Ag/NL 8 0.35 adhesion good600C/48h + 820/8h smooth surface__________________________________________________________________________ .sup.*1 Obtained by pressing the coating with two substrates on both sides; t.sub.1 and t.sub.2 are the coating thickness before and after pressing. .sup.*2 Obtained by pressing the coating to a metal substrate. .sup.*3 NL indicates pressing without lubrication. .sup.*4 TF indicates pressing with teflon sheets as lubricant.
TABLE II__________________________________________________________________________Pressing, Oxidation and Annealing Conditions With ResultantSuperconducting Properties T.sub.on /T.sub.R=0 J.sub.c (77)Alloy Substrate Treatment K A/cm.sup.2__________________________________________________________________________Bi.sub.1.4 Pb.sub.0.6 Sr.sub.2 -- Ag melt writing, without pressing, 116/106 500Ca.sub.3 Cu.sub.4 Ag.sub.21 600/40h + 820/72h Ag 600/40h + 820/80h + P.sub.1 .sup.*1 + 820/72h 116/105 800 Au same as above 114/102 400 Pt same as above 70/-- -- Pd same as above 110/75 -- Cu same as above 80/72 -- Ni same as above 76/71 -- Ag/S.S..sup.*2 same as above 114/102 450 Ag 600/40h + 820/80h + P.sub.2 .sup.*3 + 820/72h 116/107 1200 Ag 600/40h + 820/80h + P.sub.2 + 820/72h + P.sub.2 116/107 2000 800/48hBi.sub.1.4 Pb.sub.0.6 Sr.sub.2 -- Ag 500/40h + 820/80h + P.sub.1 + 830/72h 116/100 500Ca.sub.3 Cu.sub.4 Ag.sub.5Bi.sub.1.4 Pb.sub.0.6 Sr.sub.2 -- Ag 500/40h + 820/80h + P.sub.1 + 820/72h 114/104 700Ca.sub.3 Cu.sub.4 Ag.sub.11Bi.sub.1.4 Pb.sub.0.6 Sr.sub.2 -- Ag 600/40h + 820/80h + P.sub.1 + 815/72h 116/104 750Ca.sub.3 Cu.sub.4 Ag.sub.36__________________________________________________________________________ .sup.*1 P.sub.1 = Pressing with two substrates on both sides at 150-200C, pressure = 8MPa. .sup.*2 Ag/S.S. = Ag sheets covered stainless steel (304). .sup.*3 P.sub.2 = Pressing with two substrates on both sides at 150-200C, with teflon films between dies and substrates, pressure = 8MPa.
As shown in Table II, the pressed coatings on all the substrates used in the present work exhibited superconductivity after annealing. Those on Ag and Au substrates showed T R ═O ≧100K, indicating that a well developed "2223" superconductor phase was formed. The coating on Pd showed T on ═˜110K, but T R ═O ═70-80K, reflecting co-existence of "2223" and "2212" superconducting phases. Coatings on Cu and Ni showed superconducting transition temperatures of 70-80K, indicating that the superconducting phase was mainly the "2212" phase. Coatings on Pt exhibited superconducting onset temperatures around 70K, with no zero resistance temperatures. Reactions between coatings and certain of these substrates during annealing affected the formation of the superconducting phases. The "2223" phase did not form after coating reaction with Pt, Cu and Ni substrates. The "2212" superconducting phase, however, survived the reactions, probably because of its greater stability.
Substrate/coating reactions can be avoided by covering substrates with Ag sheets. Coatings pressed on Ag covered stainless steel(304) substrates exhibited T R ═O ≧100K and J c (77)=450 A/cm 2 , comparable to results with Ag and Au substrates.
Microstructural observation and microanalysis were performed with a JEOL Superprobe 733 Microanalyzer equipped with Tracor Northern 5500-5600 WDS and EDS systems. Backscattered electron images (BSE) show contrast between phases of differing chemical composition. FIGS. 3 and 4 show two BSE micrographs of longitudinal cross sectional microstructure of multilayer ribbons of Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 21 pressed on Ag and Au substrates. The ribbons were oxidized at 600° C. in 100% O 2 for 40 h, then annealed at 820° C. in 5% O 2 +95% Ar for 8 h before pressing. Pressing was conducted at 8 MPa and both sides of the coating were covered by substrates. Specimens were reannealed at 820° C. in 5% O 2 +95% Ar for 72 h. Substrates are marked to indicate Ag or Au, bright areas are Ag, plate-like, light gray grains are "2223" superconducting phase, and the dark grains are non-superconducting oxides.
As shown in FIG. 3, no gap is visible between the coating and Ag substrate, indicating that there is no coating/substrate reaction. Coating adhesion is very good. In FIG. 4, a dark area close to the Au substrate indicates that some reaction took place at that interface. The affected area was thin (5-10 μm wide), and did not compromise superconducting properties significantly.
FIGS. 5, 6 and 7 are BSE micrographs of Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 4 , Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 11 , and Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 36 coatings on Ag substrates oxidized sequentially at 500° C., 550° C. and 600° C. in 100% O 2 for 40 h, annealed at 820° C. in 5% O 2 +95% Ar for 8 h, pressed with 8 MPa and both sides covered with Ag, and reannealed at 820° C. in 5% O 2 +95% Ar for 72 h. The Ag, "2223" superconducting phase, and non-superconducting phases have contrasts similar to those in FIGS. 3 and 4. The "2223" superconducting phase (platelike, gray grains) was well developed in all three specimens consistent with the T c and J c listed in Table II. The microstructure shows apparent texture with Ag and plate-like "2223" grains aligned parallel to the substrate plane, especially for the higher Ag content specimens shown in FIGS. 6 and 7. Texturing produced by pressing deformation enhanced J c .
FIG. 8 is a BSE micrograph for a Bi 1 .4 Pb 0 .6 Sr 2 Ca 3 Cu 4 Ag 21 coating pressed on a Ag substrate by repeated pressing and annealing. Processing included oxidation at 600° C. for 40 h, annealing at 820° C. for 8 h, pressing at 8 MPa with Ag sheets and teflon films, annealing at 820° C. for 72 h, pressing under the same conditions, and reannealing at 800° C. for 48 h. The "2223" phase exhibited better developed texture than is visible in FIGS. 3, 4, 5, 6 or 7. The coating was thin (approximately 20 μm), and J c (approximately 2000 A/cm 2 ) was further improved.
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A superconductor oxide composite is prepared using a press coating technique. The coated layers on various substrates exhibit good adhesion, textured microstructure, and improved J c .
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BACKGROUND OF THE INVENTION
The present invention relates generally to equipment for pressing draperies by the application of air and steam thereto.
The pressing of draperies in cleaning and pressing establishments normally entails lengthy and tedious handling of each drapery. The considerable size and pliable nature of draperies renders same extremely awkward to handle. The large size of most draperies requires that they each be manually introduced and removed from pressing equipment by a worker or workers with considerable time being devoted to each drapery processed. The labor expense encountered by existing pressing equipment results in a high per drapery pressing cost.
SUMMARY OF THE PRESENT INVENTION
The present invention is embodied within an apparatus for processing draperies while the drapery is suspended and includes a movable series of pressing tubes cooperating with a second series of perforate tubes to impart physical pressure and a fluid flow, such as steam or air or a combination thereof, to the drapery surfaces.
The apparatus includes a movable support on which is mounted a series of tubular structures which move into intimate contact with the drapery and displace same into like contact with a second series of tubular members which may be stationary. Upright support structures define air passageways which receive a pressurized flow of air and distribute the flow into each of the tubular structures supported thereon. The stationary structure for one series of tubular structures also defines a chamber receiving and distributing a pressurized flow of air (or steam). The support structures are adapted for opening and closing movement relative to one another and to a drapery therebetween. A track supports a curtain carrying trolley which enables a worker to conveniently pull the curtain into place between the upright structures and, subsequently, remove the suspended drapery after completion of the finishing operation. Controls are provided regulating a flow of pressurized air and steam into the series of tubular structures as well as to control movement of a positionable tube support structure.
Important objectives of the present apparatus include the provision of an apparatus for pressing draperies while the latter are suspended in their normal hanging state and accordingly avoids the tedious manual operations of loading and removing the draperies from existing pressing equipment; an additional objective of the present apparatus is the pressing of draperies into the gently folded serpentine state desired whereby the drapery is finished for immediate hanging in the home or building; an additional objective is the provision of an apparatus having communicating duct structures which close into communication with one another during a pressing operation to supply tubular air members with a source of pressurized air and/or steam; the provision of an apparatus whereby a single operator may press a large number of rail supported draperies within a working shift to substantially lower per drapery pressing costs to the plant operator. These and other objectives will become subsequently apparent upon an understanding of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a perspective view of the present apparatus in an open, drapery receiving configuration;
FIG. 2 is a fragmentary side elevational view of the uppermost portions of the upright air tube support structures in an open drapery receiving position;
FIG. 3 is an elevational view of the back side of a movable air tube support structure; and
FIG. 4 is an enlarged elevational view of duct structure with outlets and air tubes attached thereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With continuing reference to the accompanying drawing wherein applied reference numerals indicate parts similarly identified in the following specification, reference numeral 1 indicates a stationary tube supporting structure while a movable tube supporting structure is indicated at 2.
The upright support structures are, generally speaking, of internally braced, panel construction having inner and outer planar surfaces at 1A-1B; 2A-2B. Support structure 1 is fixed in place on a floor surface 3 as by an angle member 4 for serving to secure the lower end of the support structure. Braces at B secure the upper end of support structure 1. Secured in place across the top of support structure 1 is a transverse duct 5 defining a chamber 6 which receives a pressurized flow of air (or steam, or steam and air) from a dispersal duct 7 which in turn receives an air flow from a blower fan 8 via a duct 9. Control means are provided at 10 for airflow regulation. Dispersal duct 7 provides a uniform flow of air into chamber 6 of duct 5.
With attention now to FIGS. 2 and 4, the fragment of chamber 6 shown therein is provided with spaced apart baffles at 11 which confine the air for downward passage into chamber outlets 12 for subsequent discharge into a first series of air tube structures each comprising a rigid tubular member 14 in endwise communication with an outlet 12 with a porous fabric sheath 15 overlying the length of the tubular member and secured as by a tie 15A about its upper end. Tubular member 14 is perforate with openings 14A spaced therealong for the outward discharge of pressurized air towards a drapery. The bottom end of each tube 14 is closed and suitably secured in place on a support 16 (FIG. 1). Fabric sheath 15 is preferably of a woven synthetic fiber.
With attention now to movable support structure 2, the upper end of same is provided with an elongate duct 17 defining a chamber 18, partitions 20 spaced thereacross. Outlets at 21 are in the form of collars to which are applied tubular members 22 all as earlier described in connection with stationary structure 1. The lower end of each tubular member 22 is closed and rests on a support 24. Desirably the tube ends and the outlets 21 are in sealed engagement as by an intermediate O-ring. No fabric sheaths are used on the tubular series in place on movable support structure 2. Again, each tube 22 is apertured at 22A along its outer surface for air dispersal toward the adjacent drapery.
With attention to transverse ducts 5 and 17, the same are each defined by top, bottom and end wall members with duct 17 additionally defined by a back wall 25. Each duct is suitably secured atop its respective upright structure and includes a resilient strip 5A, 17A to affect a seal when in abutment with one another. Duct 5 of the stationary unit 1 is, as earlier noted, in open communication with dispersal duct 7.
To provide for opening and closing movement of upright support structure 2 the same is rail supported by pairs of upper and lower gear racks indicated at 26 and 27. Upper racks 26 are secured in place on beams 29 affixed at their ends to support structure 1 and to a pair of braces at 28. Lower racks 27 are secured to floor 3. To assure uniform movement of upright structure 2, rail engaging upper and lower pinions at 30 and 31 are in toothed engagement with their respective racks.
A drive motor at 33 (FIG. 3) on support structure 2 is in driving engagement with upper and lower pinions 30 and 31 by a right angle reduction drive 34, output shaft 35, sprockets 36-37 and roller chains 38-39 which, in turn, drive sprockets 40 and 41 affixed to pinion carrying shafts 42-43. Pillow block bearings at 44 and 45 carry the shafts. Motor 33 is reversible to power support structure 2 toward and away from support structure 1. A motor control is indicated at 46 on stationary support 1. Limit switches as at 49 limit motor operation. A switch 47 on structure 1 at an operator's station is in circuit with a solenoid valve 48 in a steam line SL to permit operator control of steam flow into the airflow of duct 9 and ultimately to the draperies. Indicated at 50 at the operator's station is a blower switch for controlling motor operation of blower 8.
Draperies are manually drawn through the apparatus while suspended from a track 52 which is yieldably mounted by means of hangers at 53. The upper ends of said hangers may swing about horizontal pivots to provide a limited degree of drapery displacement during a pressing operation whereby the drapery is uniformly acted upon by the two series of tubular pressing components. Trolleys at 54 traverse the rail 52 with each serving to receive a drapery hook 55.
In operation, the drapery is suspended from trolley 53 and moved into position between the support structures 1 and 2 whereupon the structures are closed by actuation of motor control 46. Limit switch 49 (FIG. 2) serves to open the motor circuit to stop the advancement of support structure 2 in duct abutment against structure 1 with the two series of air tubes biasing opposite sides of the drapery. The operator closes a switch at 50 to energize blower fan 8, steam being injected via solenoid valve 48. The draperies are accordingly pressed for the desired duration, whereupon the air and steam are terminated prior to opening of the structures 1 and 2 for drapery removal.
While I have shown but one embodiment of the invention it will be apparent to those skilled in the art that the invention may be embodied still otherwise without departing from the spirit and scope of the claimed invention.
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An apparatus having cooperating upright structures each having a series of air carrying tubes acting on opposite sides of a drapery to press same into desired folds. The two series of tubes and upright structures are adapted for opening and closing movement during a pressing cycle. Ducting admits a pressurized airflow and steam into communicating ducts of the upright structures for dispersal by the air tubes. Some of said air tubes are covered with fabric jackets which inflate during a pressing operation.
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[0001] The invention relates to fluid flow control labyrinths and in particular labyrinths that are used to restrict water flow from emitters used in drip irrigation.
BACKGROUND OF THE INVENTION
[0002] Irrigation systems that deliver water, often containing plant nutrients, pesticides and/or medications, to plants via networks of irrigation pipes are very well known. In many such irrigation networks, water from an irrigation pipe is delivered to the plants by “emitters” or “drippers”, hereinafter generically referred to as emitters, which are connected to or installed along the length of the pipe. Each emitter comprises at least one inlet or an array of inlets through which water flowing in the pipe enters the emitter and an outlet through which water that enters the emitter exits the emitter. The emitter diverts a relatively small portion of water flowing in the pipe and discharges the diverted water to irrigate plants in a neighborhood of the location of the emitter.
[0003] Generally, to control rate of water discharge by the emitter, the emitter comprises a water flow and pressure reduction channel, a “labyrinth channel” or “labyrinth” through which water that enters the emitter must flow to reach the emitter outlet. The labyrinth channel is a high resistance flow channel along which pressure of water flowing through the emitter drops relatively rapidly with distance along the labyrinth channel from a relatively high water pressure which prevails substantially at or near the emitter inlet to a relatively low discharge pressure, generally a gauge pressure equal to about zero, substantially at or near the emitter outlet. The labyrinth channel generally comprises a tortuous “obstacle” flow path that generates turbulence in water flowing in the labyrinth to reduce water pressure and discharge of water by the emitter. Usually the obstacle path comprises a configuration of baffles that impede and introduce turbulence into water flow.
[0004] U.S. Pat. No. 4,060,200 to Mehouder, the disclosure of which is incorporated herein by reference, describes a labyrinth channel comprising two opposing arrays of equally spaced baffle “teeth” that extend out towards each other from opposite walls of the channel. Each tooth has a cross section perpendicular to the wall substantially in the shape of a truncated isosceles triangle, i.e. the apex of the triangle is “cut off”. The arrays of baffle teeth are substantially mirror images of each other but are displaced relative to each other along the channel by half a repeat period of the baffle teeth, i.e. by half the distance between adjacent baffle teeth. A tooth in one baffle array therefore faces a point in a space, hereinafter a “bay” substantially half way between adjacent baffle teeth in the other array. The tips of two adjacent baffle teeth in one baffle array in the labyrinth and the tip of the tooth in the opposing baffle array that faces the bay formed by the adjacent baffle teeth are substantially coplanar.
[0005] U.S. Pat. No. 5,207,386, the disclosure of which is incorporated herein by reference, also to Mehoudar, describes a labyrinth channel comprising a central “through-flow” flow channel that does not comprise impediments to water flow. The impediment free through-flow channel is flanked on either side by an array of equally spaced, symmetric baffle teeth, similar to the arrays of baffle teeth described in U.S. Pat. No. 4,060,200. As in U.S. Pat. No. 4,060,200, the baffle teeth arrays in U.S. Pat. No. 5,207,386 are displaced relative to each other along the labyrinth channel by half a repeat period of the baffle teeth.
[0006] U.S. Pat. No. 5,207,386 notes that a labyrinth channel comprising a central, impediment free through-flow channel, provides greater reduction in water flow pressure per unit length of the labyrinth than other labyrinth channels. The patent provides a range for the width of the through-flow channel and an optimum for its width relative to dimensions of the baffle teeth. The patent notes that the increased pressure reduction functionality results in a “comparatively low” sensitivity of outflow of water from an emitter to changes in inlet water pressure to the emitter. In addition, the improved pressure reduction functionality enables shorter labyrinth channels to be used to reduce water pressure in emitters, and as a result enables emitters to be produced less expensively.
[0007] US Patent Publication 2003/0150940, the disclosure of which is incorporated herein by reference, shows a labyrinth channel comprising two opposing rows of equally spaced baffle “fingers” that extend out towards each other from opposite walls of the channel. The tips of the finger baffles are terraced so that tips of the fingers decrease step-wise in size with height of the fingers off the floor of the channel. The labyrinth channel does not comprise a through-flow channel and tips of fingers in each row extend into spaces between fingers of the other row, i.e. the fingers mesh. All the fingers appear to be tilted at a same angle towards a downstream direction of water flow.
[0008] PCT publication WO 00/01219, the disclosure of which is incorporated herein by reference, describes a “sawblade-shaped zig-zagging” pattern comprised in a fluid flow regulatory channel of an irrigation pipe. The zig-zagging pattern is embossed on a relatively thin web of flexible plastic material. The web is folded over so that longitudinal edges of the web overlap and regions of the overlapping edges are welded to form the irrigation pipe and regulatory channel comprising the zig-zagging pattern.
SUMMARY OF THE INVENTION
[0009] An aspect of some embodiments of the invention relates to providing a labyrinth channel that comprises a new configuration of baffles for reducing pressure in a fluid that flows through the channel and/or the fluid flow rate through the channel.
[0010] An aspect of some embodiments of the invention relates to providing a labyrinth channel comprising opposing arrays of baffle teeth that extend toward each other from opposite side walls of the channel and for which upstream and downstream sides of the baffle teeth have different configurations and are not parallel. Baffle teeth in different arrays have a same shape and upstream sides of closest baffle teeth in different arrays have different configurations and/or downstream sides of closes baffle teeth in different arrays have different configurations. A configuration of a side of a baffle tooth refers to a geometrical shape of the side and/or orientation of the side. Hereinafter an upstream or downstream side of a baffle tooth is referred to as a “face” and baffle faces having different configurations are referred to as being different.
[0011] In an embodiment of the invention, each array of baffle teeth in a labyrinth channel comprises baffle teeth, hereinafter “shark-fin baffle teeth”, which have a cross section shape reminiscent of a shark's dorsal fin. Each shark-fin baffle tooth has an optionally planar “leading-edge face surface” and an optionally planar “trailing-edge face surface”. The leading-edge face surface is more swept back with respect to the side-wall of the channel from which the tooth extends than the trailing-edge face surface. The leading-edge face surface is oriented at an angle with respect to the side wall that is more acute than an angle that the trailing-edge face surface makes with the side wall.
[0012] In an embodiment of the invention, the leading-edge face surfaces of shark-fin baffle teeth in one array and their nearest shark-fin baffle teeth “neighbors” in the other array face in opposite upstream and downstream directions. That is, the leading-edge face surfaces of baffle teeth in the first array and the trailing-edge face surfaces of their nearest baffle teeth neighbors in the other array face in a same upstream or downstream direction.
[0013] Optionally, the shark-fin baffle teeth in a same array are equidistant from each other and are positioned so that the baffle teeth in one array are located opposite the bay regions between adjacent baffle teeth in the other array. Optionally, the baffle teeth in the opposing arrays mesh. Optionally, the tips of two adjacent shark-fin baffle teeth in one baffle array in the labyrinth and the tip of the shark-fin baffle tooth in the opposing baffle array that faces the bay between the two adjacent baffle teeth are substantially coplanar. In some embodiments of the invention, the labyrinth channel comprises a through-flow channel located between the opposing arrays of shark-fin baffles.
[0014] There is therefore provided in accordance with an embodiment of the invention, a labyrinth channel for reducing pressure and/or flow rate in a liquid flowing in the channel, the labyrinth channel having a bottom surface and first and second opposing walls and comprising: a first array of spaced apart first baffle teeth that have non-parallel upstream and downstream faces and extend from the first wall towards the second wall to terminate in an end; a second array of spaced apart second baffle teeth that have non-parallel upstream and downstream faces and extend from the second wall towards the first wall to terminate in an end; wherein baffle teeth in different arrays have a substantially same shape and upstream faces of closest baffle teeth in different arrays are different and/or downstream faces of closest baffle teeth in different arrays are different.
[0015] Optionally, ends of the first teeth are contiguous with or intersect a same first surface that follows a contour of the labyrinth flow channel. Optionally, ends of the second teeth are contiguous with or intersect a same second surface that follows a contour of the labyrinth flow channel. Optionally, the first and second surfaces that follow the channel contour are coincident. Alternatively, the first and second surfaces that follow the channel contour are parallel and displaced one from the other.
[0016] In some embodiments of the invention, each tooth has a planar trailing-edge surface that makes an external angle β with the wall from which the tooth extends. Optionally, β has a value less than or equal to 100°. Alternatively or additionally, β optionally has a value greater than or equal to 80°. Optionally, β has a value substantially equal to 90°.
[0017] In some embodiments of the invention, each tooth has a planar leading-edge surface that makes an included angle α with the trailing edge surface. Optionally, α has a value less than or equal to 45°. Additionally or alternatively, α optionally has a value greater than or equal to 15°.
[0018] In some embodiments of the invention, the value of α is the same for all baffle teeth. In some embodiments of the invention, the value of β is the same for all baffle teeth.
[0019] In some embodiments of the invention, one of the leading-edge and trailing-edge face surfaces of a tooth is an upstream face of the tooth. Optionally, if the upstream face of a first tooth is a leading-edge surface of the tooth, the downstream face of the nearest second tooth is the leading-edge surface of the second tooth.
[0020] In some embodiments of the invention, the upstream and downstream faces of a first baffle tooth are respectively parallel with the downstream and upstream faces of a nearest second baffle tooth. Optionally, a distance between the upstream face of a first baffle tooth and a nearest downstream face of a second baffle tooth is equal to a same distance “A” between the downstream face of the first baffle tooth and the nearest upstream face of a second baffle tooth. Optionally, A is less than or equal to 3 mm. Additionally or alternatively, A is greater than or equal to 0.3 mm.
[0021] In some embodiments of the invention, ends of the first and second teeth are located a same distance B from the respective walls from which they extend. Optionally, the channel has a width greater than 2 B. Alternatively, the channel has a width optionally less than 2 B. Optionally, the channel has a width substantially equal to about 2 B. In some embodiments of the invention, B is greater than A.
[0022] In some embodiments of the invention, the leading-edge and trailing-edge face surfaces intersect a common surface at different locations of the common surface to define an end surface of the tooth. Optionally, the common surface is planar. Optionally, the intersections of the leading and trailing edge surfaces are different parallel straight lines.
[0023] In some embodiments of the invention, the labyrinth channel or portion thereof is straight. In some embodiments of the invention, the labyrinth channel or a portion thereof is circular. In some embodiments of the invention, the bottom surface of the labyrinth channel or portion thereof is substantially a circularly cylindrical surface.
BRIEF DESCRIPTION OF FIGURES
[0024] Non-limiting examples of embodiments of the present invention are described below with reference to figures attached hereto. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same symbol in all the figures in which they appear. Dimensions of components and features shown in the figures are chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.
[0025] FIG. 1A schematically shows a perspective view of an irrigation pipe having an optionally internally mounted emitter comprising a labyrinth channel, in accordance with an embodiment of the invention;
[0026] FIG. 1B schematically shows an enlarged view of a portion of the emitter shown in FIG. 1A ;
[0027] FIG. 1C schematically shows a plan view of the emitter shown in FIG. 1A ;
[0028] FIG. 1D schematically shows an enlarged view of a portion of the plan view shown in FIG. 1C greatly enlarged;
[0029] FIGS. 2A and 2B schematically show perspective and plan views of a circular labyrinth in accordance with an embodiment of the invention;
[0030] FIGS. 3A and 3B schematically show perspective and side views of a cylindrical labyrinth in accordance with an embodiment of the invention; and
[0031] FIG. 4 schematically shows a plan view of a portion of a labyrinth similar to the labyrinth shown in FIG. 1B and FIG. 1D , in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0032] FIG. 1A schematically shows a perspective view of a portion of an irrigation pipe 20 having an internally mounted emitter 30 comprising a labyrinth channel 40 , in accordance with an embodiment of the invention. An enlarged view of a portion of emitter 30 is shown in FIG. 1B . The enlarged portion of emitter 30 that is shown in FIG. 1B is indicated by an ellipse 31 in FIG. 1A . FIG. 1C schematically shows a plan view of emitter 30 and a portion, indicated by ellipse 33 , of emitter 30 in FIG. 1C is shown greatly enlarged in FIG. 1D . Emitter 30 is optionally formed from a plastic and is bonded to an inside surface 22 of irrigation pipe 20 using any of various methods, such as thermal or ultrasound welding, known in the art. After bonding to surface 22 , the portion of the surface to which it is bonded optionally forms a wall, or “roof” of the emitter that delimits labyrinth channel 40 . In FIGS. 1B-1D surfaces of emitter 30 that are bonded to inside surface 22 of pipe 20 are shown shaded. Irrigation pipe 20 is formed with outlet orifices 21 from which fluid that emitter 30 diverts from fluid flowing in the pipe is discharged.
[0033] Emitter 30 is optionally formed having a plurality of inlet apertures 32 optionally located along an upper edge surface of the emitter which is bonded to inside surface 22 of irrigation pipe 20 . Optionally, emitter 30 is formed with additional inlet apertures (not shown) on a bottom surface of the emitter, which surface is not seen in the perspectives of FIGS. 1A-1D .
[0034] Water in irrigation pipe 20 enters emitter 30 through inlet apertures 32 at a relatively high inlet pressure equal to the water pressure in the irrigation pipe at the location of the emitter and flows into an optionally circumferential inlet channel 34 . Water entering the emitter through inlet apertures 32 is schematically indicated for some of the apertures by bold dashed arrows 24 . In inlet channel 34 the water flows in an optionally counterclockwise direction indicated by bold dashed arrows 25 until it reaches and enters an inlet portal 36 of labyrinth channel 40 . The inlet portal, labyrinth channel 40 and water flow in the labyrinth channel are most clearly shown in FIGS. 1C and 1D .
[0035] Water that enters labyrinth inlet portal 36 flows generally in an optionally clockwise direction indicated by arrows 27 through labyrinth channel 40 until it reaches a labyrinth outlet portal 37 from which it exits the labyrinth and empties into a discharge reservoir 39 . Because of the presence and configuration of baffle teeth arrays 45 and 46 , labyrinth channel 40 is characterized by a relatively high resistance to water flow per unit length of the labyrinth. As a result, pressure of water that entered the channel at the relatively high inlet pressure drops rapidly per unit length of the labyrinth as the water flows through the labyrinth and the water flows into a discharge reservoir 39 at a relatively low flow rate and gauge pressure, optionally substantially equal to about zero. Water in discharge reservoir 39 drips out of irrigation pipe 20 via discharge apertures 21 that communicate with discharge reservoir 39 at a relatively low “drip” flow rate. Water discharging from the discharge apertures is indicated by dashed arrows 29 in FIG. 1A .
[0036] Labyrinth channel 40 optionally comprises an outer wall 41 and an inner wall 42 that extend from a channel floor and define a perimeter of the channel and two channel sections 40 a and 40 b . Labyrinth channel 40 is lined with opposing arrays 45 and 46 of baffle teeth in accordance with an embodiment of the invention. Array 45 comprises optionally shark-fin baffle teeth 47 that extend from outer wall 41 towards inner wall 42 and array 46 comprises optionally shark-fin baffle teeth 48 that extend from inner wall 42 towards outer wall 41 . Optionally, baffle teeth 47 and 48 have similar shapes and may be transformed one into the other by rotation and/or translation. Each pair of adjacent baffle teeth 47 delineate a bay 51 between them and each pair of adjacent baffle teeth 48 delineate a bay 52 between them. Optionally, the baffle teeth are equally spaced one from the other in their respective arrays by a same distance. Details of shark-fin baffle teeth 47 and 48 are most clearly shown in FIGS. 1B and 1D .
[0037] Each shark-fin baffle tooth 47 and 48 has a swept back leading-edge face surface 61 and a trailing-edge surface 62 . In a given baffle tooth 47 or 48 the trailing-edge surface 62 makes an external angle β ( FIG. 1D ) with the wall 41 or 42 respectively from which it extends and an internal “included” tooth angle α with the leading-edge face surface 61 of the given baffle tooth. Angle α is optionally between 15° and 45° and angle β is optionally between 80° to 100° and preferably substantially equal to 90°. In accordance with an embodiment of the invention, as shown in FIGS. 1A-1D , an upstream face of a baffle tooth in one array is parallel to the downstream face of its nearest neighbor in the opposing array. Leading and trailing-edge face surfaces 61 and 62 of a given baffle tooth 47 or 48 intersect a relatively narrow optionally rectangular, planar end surface 64 ( FIG. 1B ) of the tooth. Optionally, end surfaces 64 of teeth in opposing baffle teeth arrays 45 and 46 are substantially coplanar and lie substantially on or intersect a same plane schematically indicted in FIGS. 1B and 1D by a dashed line 50 . (It is noted that if a labyrinth such as labyrinth 40 is produced by injection molding, dies for producing the labyrinth may in some instances require that surfaces of features of the labyrinth, such as face and end surfaces 61 , 62 and 64 of baffle teeth 47 and 48 be slightly angled at a release angle. The release angle allows satisfactory release of the labyrinth from the die that produces it after production. In FIG. 1D a die release angle would result in surfaces 61 , 62 and 64 being slightly tilted away from the normal to the plane of the figure. End surfaces 64 would then intersect the planar surface indicated by numeral 50 at the release angle and not lie completely on the surface.)
[0038] In accordance with an embodiment of the invention, an upstream face of a baffle tooth in one array is different, i.e. has a different configuration, respectively from the upstream face of its nearest neighbors in the opposing array and/or a downstream face of a baffle tooth in one array is different from the downstream face of its nearest neighbors in the opposing array. Optionally, in section 40 a of labyrinth 40 , leading-edge face surfaces 61 of each baffle tooth 47 in array 45 faces upstream and leading-edge face surfaces 61 of its nearest baffle teeth neighbors 48 in array 46 face downstream. Optionally, in section 40 b of labyrinth 40 , leading-edge faces 61 of each baffle tooth 47 face downstream while the leading-edge face surfaces of its nearest opposing neighbors face upstream. It is noted that whereas in labyrinth 40 , baffle teeth in different sections, i.e. 40 a and 40 b , of the array are shown facing opposite upstream and downstream directions, a labyrinth in accordance with an embodiment of the invention, similar to labyrinth 40 , may have baffle teeth in a same array in different sections of the labyrinth face a same direction.
[0039] Dimensions of features of labyrinth channel 40 are labeled in FIG. 1D . The labyrinth channel has a depth “D”, schematically indicated by a circle with a cross inside to indicate a direction perpendicular to the plane of the figure and width “W”. Baffle teeth 47 extend from their associated wall 41 into the channel a distance “B 1 ” and baffle teeth 48 extends from their associated wall 42 into the channel a distance “B 2 ”. As a result, bays 51 and 52 have a depth respectively equal to B 1 and B 2 . Optionally, as indicated in FIG. 1D , end surfaces 64 of baffle teeth 47 and 48 are substantially coplanar so that W=B 1 +B 2 . Optionally B 1 is equal to B 2 . A leading-edge face surface 61 of a baffle tooth 47 and a nearest leading-edge face surface 61 of a baffle tooth 48 are separated by a distance “A 1 ”. A trailing-edge face surface 62 of a baffle tooth 47 and a nearest trailing-edge face surface 61 of a baffle tooth 48 are separated by a distance “A 2 ”. Optionally, A 1 =A 2 . Optionally, distance between an end surface 64 of a given baffle tooth 47 , 48 and the opposing wall 42 , 41 towards which the given tooth extends, is respectively larger than A 1 or A 2 and preferably at least equal to B 2 or B 1 respectively. End surfaces 64 have a width “e” and baffle teeth 47 and 48 in a same array 45 and 46 respectively are separated by a distance “L”. For the exemplary embodiment of the invention shown in FIGS. 1A-1D , for which an upstream face of a baffle tooth in one array is parallel to the downstream face of its nearest neighbor in the opposing array, L=A 1 /cos α+A 2 /sin β+2 e.
[0040] By way of a numerical example, optionally, A 1 and A 2 satisfy a relationship 3 mm≧A 1 , A 2 ≧0.3 mm and A 1 =A 2 =A. Optionally B 1 =B 2 =B and A and B satisfy a relationship of 2 A≧B≧A. Optionally, 2 A≧D≧0.5 A and 0≧e≧0.25 A.
[0041] The inventors have performed theoretical studies of the efficiency of a labyrinth channel in accordance with an embodiment of the invention that is similar to labyrinth channel 40 and has dimensions similar to those noted above. The studies indicate that per unit length, a labyrinth channel in accordance with an embodiment of the invention provides resistance to fluid flow that is greater than that provided by prior art labyrinth channels having similar dimensions. In particular, the studies indicate that the turbulence or “head loss” coefficient “K” for a single baffle tooth in a labyrinth in accordance with an embodiment of the invention may be as much as 16% greater than that of prior baffle teeth in prior art labyrinths having similar dimensions.
[0042] As a result of the improved resistance to fluid flow per unit length, a labyrinth configuration in accordance with an embodiment of the invention provides greater design latitude in tailoring a labyrinth to a given desired range in pressure drop between an inlet and an outlet of the labyrinth and/or flow rates through the labyrinth than conventional labyrinth configurations.
[0043] For example, for a given desired or anticipated pressure drop, a labyrinth in accordance with an embodiment of the invention can generally be made shorter than a conventional labyrinth. An emitter comprising a shorter labyrinth, is generally less expensive to make and less prone to clogging by particulate matter in fluids discharged by the emitter than an emitter comprising a longer labyrinth. Alternatively, for a given pressure drop, and a same length, a labyrinth in accordance with an embodiment of the invention can be made wider than a conventional labyrinth. A wider labyrinth is usually less prone to trapping particulate matter and clogging than a narrower labyrinth and can be particularly advantageous for use in environments for which fluids discharged by an emitter comprising the labyrinth are expected to be unusually adulterated by particulate matter. Additionally, for a same length, width and operating pressure range drop, a labyrinth in accordance with an embodiment of the invention may advantageously be used to provide a lower fluid flow rate than a conventional labyrinth. For example, for a same pressure operating range of an irrigation emitter, and same length and width of a labyrinth in the emitter, an emitter comprising a labyrinth in accordance with an embodiment of the invention may provide a lower drip rate than a conventional emitter.
[0044] It is noted that whereas in the exemplary embodiment of the invention shown in FIGS. 1A-1D , labyrinth channel 40 comprises straight sections, the invention is not limited to straight labyrinths. A labyrinth in accordance with an embodiment of the invention may, for example be curvilinear, elliptical, circular or cylindrical and is not limited to planar labyrinths.
[0045] FIGS. 2A and 2B schematically show perspective and plan views of a circular emitter labyrinth channel 100 , in accordance with an embodiment of the invention. In the figures only features of the emitter that are germane to labyrinth channel 100 are shown. Water optionally enters labyrinth channel 100 through an inlet portal 101 and empties into a discharge reservoir 102 via an outlet portal 103 . Water flow is indicted by dashed arrows 104 .
[0046] Labyrinth channel 100 comprises an inner array 110 of optionally shark-fin baffle teeth 112 and an opposing outer array 111 of shark-fin baffle teeth 113 . Shark-fin baffle teeth 112 and 113 have leading-edge face surfaces 116 ( FIG. 2B ) and trailing-edge face surfaces 118 and ends 117 . Optionally, ends 117 lie substantially on or intersect a same circularly cylindrical surface indicated by a dashed line 121 . By way of example, leading-edge surfaces 116 of baffle teeth 113 in array 111 face upstream while leading-edge surfaces 116 of baffle teeth 112 in array 110 face downstream. It is noted that in labyrinth channel 100 all the baffle teeth in a same array, optionally as shown in FIGS. 2A and 2B , face a same direction.
[0047] FIGS. 3A and 3B schematically show perspective and plan views of a cylindrical emitter labyrinth channel 140 , in accordance with an embodiment of the invention. Only features of the emitter that are germane to labyrinth channel 140 are shown. Water optionally enters labyrinth channel 140 through an inlet portal 141 and empties into a discharge reservoir, not shown, via an outlet portal 142 . Water flow is indicted in FIG. 3B by dashed arrows 144 .
[0048] Labyrinth channel 140 comprises an upper array 150 of optionally shark-fin baffle teeth 152 and an opposing lower array 151 of shark-fin baffle teeth 153 . Shark-fin baffle teeth 152 and 153 have leading-edge face surfaces 156 , trailing edge face surfaces 158 and ends 157 . Optionally ends 157 are substantially coplanar and lie substantially on or intersect a same plane schematically indicted by a dashed line 221 . By way of example, leading-edge surfaces 156 of baffle teeth 152 face downstream while leading edge surfaces 156 of baffle teeth 153 face upstream.
[0049] It is noted that in the above embodiments of the invention, ends of baffle teeth in different opposing arrays of baffle teeth comprised in a labyrinth are indicated as being contiguous with a same surface, a “contour surface”, that follows a contour of the labyrinth. For example, the ends of baffle teeth in opposing arrays of labyrinth 40 and 140 ( FIGS. 1B , 1 D, 3 A, 3 B) are indicated as lying in or intersecting a same plane while baffle teeth in opposing arrays of labyrinth 100 lie on or intersect a same circularly cylindrical surface ( FIGS. 2A , 2 B). In some embodiments of the invention, ends of baffle teeth in different opposing arrays are not contiguous with a same contour surface. In some embodiments of the invention, ends of baffle teeth in a same array of opposing arrays of baffle teeth in a labyrinth are contiguous with a same contour surface while ends of baffle teeth in different arrays are contiguous with different parallel contour surfaces.
[0050] By way of example, FIG. 4 schematically shows a plan view of a portion of a labyrinth 200 similar to labyrinth 40 shown in FIG. 1B and FIG. 1D . However, whereas in labyrinth 40 , ends 64 of opposing baffle teeth 47 and 48 are substantially contiguous with a same plane 50 , in labyrinth 200 ends 64 of baffle teeth 47 are coplanar with a plane 201 while ends 64 of opposing baffle teeth 48 are coplanar with a different plane 202 parallel to plane 201 but displaced from plane 201 by a distance “d”.
[0051] It is further noted that whereas in the above discussion it is indicted that a labyrinth may be produced by injection molding, a labyrinth in accordance with an embodiment of the invention is not limited to production by injection molding but may of course be produced using any suitable method known in the art. For example a labyrinth in accordance with an embodiment of the invention may be produced by embossing on a suitable plastic material. In addition a “roof” of a labyrinth in accordance with an embodiment of the invention is not necessarily provided by a wall of an irrigation pipe with which it is used but may be provided in part or completely by a component that is not a part of the wall. It is also noted that a labyrinth in accordance with an embodiment of the invention is not limited to being used with emitters that are internally mounted to an irrigation pipe, but may of course be comprised in emitters that are coupled externally to an irrigation pipe or inline between portions of an irrigation pipe. In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
[0052] The invention has been described with reference to embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the described invention and embodiments of the invention comprising different combinations of features than those noted in the described embodiments will occur to persons of the art. The scope of the invention is limited only by the following claims.
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A labyrinth channel for reducing pressure and/or flow rate in a liquid flowing in the channel, the labyrinth channel having a bottom surface and first and second opposing walls and comprising: a first array of spaced apart first baffle teeth that have non-parallel upstream and downstream faces and extend from the first wall towards the second wall to terminate in an end; and a second array of spaced apart second baffle teeth that have non-parallel upstream and downstream faces and extend from the second wall towards the first wall to terminate in an end; wherein baffle teeth in different arrays have a substantially same shape and upstream faces of closest baffle teeth in different arrays are different and/or downstream faces of closest baffle teeth in different arrays are different.
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BACKGROUND OF THE INVENTION
The invention relates to a particle injector for introducing particles into a carrier flow of a microfluidic system, in particular for injecting biological cells into the carrier flow of a cell sorter, according to the preamble of claim 1 .
U.S. Pat. No. 5,489,506 discloses a cell sorter which enables biological cells to be separated dielectrophoretically in a carrier flow, whereby the dielectrophoretic effects used for separating are described for example in MÜLLER, T. et al. : “A 3-D microelectrode system for handling and caging single cells and particles”, Biosensors & Bioelectronics 14 (1999) 247-256. The biological cells to be sorted are hereby injected by a particle injector into the carrier flow, whereby the carrier flow enters the particle injector via an inlet and later leaves it along with the injected biological cells via an outlet. The actual injecting of the biological cells to be sorted takes place through an injection needle, which is stuck through a septum in the particle injector and is guided coaxially into the carrier flow between the inlet and the outlet of the particle injector, so that the cells introduced via the injection needle are carried along by the carrier flow.
The disadvantage to this known particle injector is the loss of cells, arising from cell depositing in the particle injector. In the extreme case these cell deposits can result in clogging of the particle injector, impairing the feed of the carrier flow or to total obstruction. This has a particularly strong effect in fluidic systems with minimal feed rates of e.g. less than 200 μl/h.
The object of the invention therefore is to minimize the loss of cells through particle depositing in the above described known particle injector to prevent obstruction of the particle injector.
SUMMARY OF THE INVENTION
In particular a particle injector is to be provided, which selectively enables continuous or discontinuous injection of particles in a fluidic microchip (“Lab-on-Chip”), whereby the most uniform possible incessant (e.g. in the range of hours), loading of the system with particles is achieved. In addition, scattering of the particles is also ensured, thus counteracting interfering aggregate formation.
So as to prevent obstruction of the particle injector the carrier flow channel between the inlet of the particle injector and the outlet of the particle injector preferably has no dead volume, to avoid particles being stopped in the flow channel.
The carrier flow channel of the particle injector therefore preferably has a smooth inner contour without projections or depressions, which could hinder a laminar flow course. When considered as mathematically idealized the inner contour of the carrier flow channel therefore preferably has a constantly differentiable top surface.
The carrier flow channel in the particle injector between the inlet and the outlet preferably even has a constant cross-section of flow, since each change in cross-section in the carrier flow channel facilitates particles being stopped.
The cross-section of the carrier flow channel is preferably circular, however with the inventive particle injector the carrier flow channel can also be formed elliptical or angular.
In the preferred embodiment of the invention the injection channel for injecting the particles terminates obtusely and preferably right-angled in the carrier flow channel, so that the particle injector can also be described as a T injector. The advantage of such a geometric arrangement of the injection channel is that the carrier flow flowing in the carrier flow channel carries along the particles to be injected. The invention is however not limited with respect to the geometric arrangement of the injection channel to obtuse confluence of the injection channel in the carrier flow channel. It is also possible for example that the injection channel, as explained for the abovementioned U.S. Pat. No. 5,489,506, runs coaxially to the carrier flow channel so as to inject the particles coaxially into the carrier flow.
With the inventive particle injector the injection channel preferably serves not only for injecting the particles, but also for mechanical guiding of an injection needle, which can be stuck for example in through a septum and guided into the injection channel. The injection channel therefore preferably has an inner diameter, which is slightly greater than the outer diameter of the injection needle. With the injection channel of the particle injector the injection needle preferably forms a loose fit or transition fit to achieve good mechanical guiding of the injection needle.
Inserting the injection needle into the injection channel can be made easier in the inventive particle injector by a feeding-in aid, preferably comprising funnel-shaped cross-sectional widening of the injection channel. The feeding-in aid for the injection needle is preferably arranged in a separate component, attached detachably to the particle injector. By way of example this component serving as feeding-in aid can be screwed separately onto the particle injector or connected in some other way to the particle injector. By way of alternative however it is also possible that the feeding-in aid is arranged monobloc on the particle injector, so that a separate component as feeding-in aid can be dispensed with.
The abovementioned septum for sealing off the injection channel is preferably exchangeable and constructed multilayer. By way of example the septum can have a silicon core, coated on both sides with Teflon.
The fluidic contacting of the inventive particle injector occurs preferably by way of hoses, which are fastened on the inlet or respectively the outlet of the particle injector. With this fluidic contacting it is desirable that at the transition point between the hoses and the carrier flow channel as far as possible no cross-sectional leaks occur, so as to prevent depositing of particles there. To facilitate correct mounting of the hoses the inventive particle injector therefore preferably has at the inlet and/or the outlet a centering aid so that the hose is mounted as coaxially as possible to the carrier flow channel.
Such a centering aid can for example comprise a substantially hollow-cylindrical pick-up, which borders the carrier flow channel and is arranged coaxially to the carrier flow channel, whereby the inner diameter of the pick-up is greater by the wall thickness of the line to be connected than the inner diameter of the carrier flow channel. The line is therefore inserted into the hollow-cylindrical pick-up, which runs coaxially to the carrier flow channel and thereby ensures corresponding coaxial alignment to the line.
In a variant of the invention injecting the particles into the carrier flow channel takes place with respect to the gravity acting on the particle injector from top to bottom preferably vertically, whereby the injection channel is arranged on the top side of the particle injector. With such an arrangement of the injection channel above the carrier flow channel the effect of gravity favors introducing the particles into the carrier flow channel.
Here it is possible that the cross-section of the injection channel tapers conically down to the carrier flow channel, which also supports introducing an injection needle into the injection channel. In addition to this, the conical tapering of the injection channel also has a funneling function, as the particles converge in the lower region of the injection channel, so that no or only some particles remain caught in the injection channel, guaranteeing continuous particle feeding.
By way of example, the injection channel can taper to the carrier flow channel with a conic angle between 5° and 45°, whereby any intermediate values are possible.
In another variant of the invention the inlet of the carrier flow channel on the other hand is arranged on the underside of the particle injector, while the outlet of the carrier flow channel is located on the top side of the particle injector, so that the carrier flow is directed from the bottom to the top. The injection channel can hereby terminate to the side in the carrier flow channel, whereby the carrier flow channel preferably has a cross-section, which widens out from the inlet to the outlet. By way of example, the carrier flow channel can narrow conically to the inlet with a conic angle of between 5° and 45°, whereby any intermediate values are possible. Such narrowing of the cross-section of the carrier flow channel to the subjacent inlet is advantageous, since this counteracts any occluding of the carrier flow channel. In this way sedimentation effects in the carrier flow channel could lead to particle deposits in the lower region of the carrier flow channel. The narrowing of the cross-section in the lower region of the carrier flow channel however leads to a corresponding increase in the flow rate, thus extensively avoiding sedimentation deposits with the danger of occlusion.
The carrier flow channel between the inlet and the outlet preferably has a volume of between 0.02 μl and 5 μl, where any intermediate values are possible. Though there is also the possibility that the volume of the carrier flow channel between the inlet and the outlet is between 20 μl and 50 μl, whereby likewise any intermediate values are possible. Furthermore, this volume can even be up to 1 ml or more, with volumes of between 0.02 μl and more than 1 ml possible.
There is also the possibility that the injection channel terminates obliquely upwards in the carrier flow channel, whereby the carrier flow channel preferably runs vertically. With the carrier flow channel flowing through from bottom to top the suspended particles are then carried along upwards and are flushed out of the particle injector. The angle between the injection channel and the carrier flow channel can hereby for example be between 10° and 80°, whereby any intermediate values are possible.
In addition to this, an agitation chamber, in which a magnetic stirring rod is located, can be arranged in the particle injector. This advantageously enables the carrier flow with the particles suspended therein in the agitation chamber to be intermixed with a conventional magnetic stirrer.
Several inlets and/or several outlets for the carrier flow can be arranged parallel to one another. In addition to this, there is also the possibility for several particle inlets to be provided.
The inventive particle injector can also have two carrier flow inlets, via which the two carrier flows are fed, whereby both carrier flow inlets preferably terminate in a single carrier flow outlet. Both the carrier flow inlets can hereby be arranged laterally and opposite one another.
It is a further advantage if the carrier flow channel in the particle injector is guided meandering between the inlet and the outlet. Due to the narrowing and widening in the carrier flow channel the sedimentizing of the particles in the carrier flow channel is countered, so that the suspended particles move uniformly and continuously.
It should also be mentioned that the inventive particle injector can preferably be autoclaved so as to enable sterilization of the particle injector. A suitable material for the particle injector therefore is preferably PEEK, however the inventive particle injector can also comprise other materials.
It is also advantageous if the particle injector comprises a heat-conductive material, so as to measure or influence the temperature of the particle injector. The particle injector is preferably therefore connected to a temperature sensor and/or a tempering element, whereby the tempering element preferably enables both heating and also cooling of the particle injector and for example may comprise a Peltier element.
The inventive particle injector can be made for example by machining methods or an injection molding process, however the invention is not limited to these particular manufacturing methods.
In addition to this, the invention also comprises a microfluidic system with the inventive particle injector, whereby the particle injector is preferably arranged in a carrier flow line, terminating in a cell sorter.
In an embodiment of such a microfluidic system several inventive particle injectors can be arranged in the carrier flow line behind one another, so that different particles can be injected successively. Instead of particles specific reagents or reaction solutions can also be added via the individual particle injectors in each case.
It should also be mentioned that the term particle used within the scope of the invention is to be understood generally, and is not limited to individual biological cells. Rather, the inventive particle injector can operate with various types of particles, in particular synthetic or biological particles. Specific advantages will emerge if the particles include biological materials, therefore for example biological cells, cell groups, cell constituents or biologically relevant macromolecules, in each case if required in combination with other biological particles or synthetic carrier particles.
Synthetic particles can include solid particles, liquid particles separated out from the suspension medium, or multi-phase particles, which form a separate phase relative to the suspension medium in the carrier flow channel.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
Other advantageous further developments of the invention are characterized in the independent claims or are explained in greater detail hereinbelow along with the description of the preferred embodiments of the invention by way of the figures, in which:
FIG. 1 illustrates a cell sorter with an inventive particle injector,
FIGS. 2 to 4 illustrate cross-sectional views of various alternative embodiments of the particle injector,
FIG. 5 illustrates a side elevation of a feeding-in aid for easing insertion of an injection needle into the inventive particle injectors,
FIG. 6 illustrates a variant of a microfluidic system with an inventive particle injector,
FIG. 7 illustrates a further embodiment of an inventive particle injector with integrated magnetic stirring rods,
FIG. 8 illustrates a further embodiment of an inventive particle injector with angled guiding of the carrier flow,
FIG. 9 illustrates an embodiment of an inventive particle injector, in which the particles are injected obliquely into the carrier flow,
FIG. 10 illustrates another embodiment of an inventive particle injector with two opposing carrier flow feeds,
FIG. 11 illustrates a perspective illustration of an inventive particle injector, and
FIG. 12 illustrates a further embodiment of an inventive particle injector with meandering guiding of the carrier flow channel.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The schematic illustration in FIG. 1 shows an inventive cell sorter, which sorts biological cells dielectrophoretically by means of a microfluidic sorter chip 1 .
The techniques of the dielectrophoretic influence of biological cells are described for example in MÜLLER T. et al. : “A 3-D microelectrode system for handling and caging single cells and particles”, Biosensors & Bioelectronics 14 (1999) 247-256, so that a detailed description of the dielectrophoretic processes in the sorter chip 1 are dispensed with hereinbelow, and this is pointed out with respect to the above publication.
The sorter chip 1 has several terminals 2 - 6 for fluidic contacting whereby fluidic contacting of the terminals 2 - 6 is described in DE 102 13 272, the content of which is incorporated herein by reference.
The terminal 2 of the sorter chip 1 serves to receive a carrier flow with the biological cells to be sorted, while the terminal 3 of the sorter chip 1 serves to discard the selected biological cells, which are no longer being inspected on the sorter chip 1 . The selected biological cells can be intercepted by an injection 7 , which can be connected to the terminal 3 of the sorter chip 1 . The output 5 of the sorter chip 1 on the other hand serves to reject the interesting biological cells, which are then further processed or inspected.
The purpose of the terminals 4 and 6 of the sorter chip 1 is to feed a so-called shell flow, whereof the task is to guide the selected biological cells to the terminal 5 of the sorter chip 1 . With respect to the functioning of the shell flow reference is made to the German patent application DE 100 05 735, so that a detailed description of the functioning of the shell flow can be omitted.
The terminals 4 and 6 of the sorter chip are connected via two shell flow lines 8 , 9 , a Y piece 10 and a four-way valve 11 with a pressurized container 12 , in which there is a cultivation medium for the shell flow. Instead of the cultivation medium, however, in the pressurized container 12 there can also be a so-called manipulation buffer.
The pressurized container 12 is set on a compressed air line 13 at superpressure, so that with corresponding adjustment of the four-way valve 11 the cultivation medium in the pressurized container 12 flows via the Y piece 10 and the shell flow lines 8 , 9 to the terminals 4 , 6 of the sorter chip 1 .
The terminal 2 of the sorter chip 1 by way of comparison is connected via a carrier flow line 14 to a particle injector 15 , whereof various alternative embodiments are illustrated in FIGS. 2 to 4 and are described hereinbelow in greater detail.
Upstream the particle injector 15 is connected via a T piece 16 to a carrier flow injection 17 , driven by machine and injecting a preset liquid flow of a carrier flow.
In addition to this, the T piece 16 upstream is connected via a further four-way valve 18 and a shell flow line 19 to a three-way valve 20 . The three-way valve 20 enables flushing of the shell flow lines 8 , 9 as well as the carrier flow line 14 prior to actual running.
For this purpose the three-way valve 20 upstream is connected via a peristaltic pump 21 to three three-way valves 22 . 1 - 22 . 3 , to which in each case an injection reservoir 23 . 1 - 23 . 3 is attached. The injection reservoirs 23 . 1 - 23 . 3 hereby serve to feed a filling flow for flushing the entire fluidics system prior to actual operation, whereby the injection reservoir 23 . 1 contains 70% ethanol, whereas the injection reservoir 23 . 2 contains Aqua destillata as filling flow substance. The injection reservoir 23 . 3 finally contains a buffer solution as filling flow substance, whereby alternatively another manipulation solution can also be used as filling flow substance, such as for example a physiological saline solution.
Also, the cell sorter has a collection container 27 for excess shell flow as well as a collection container 28 for excess filling flow.
Hereinafter the flushing procedure is first described, which is carried out prior to actual operation of the cell sorter so as to free the shell flow line 8 , 9 , the carrier flow line 14 and the remaining fluidics system of the cell sorter of air bubbles and contaminants.
For this purpose first the three-way valve 22 . 1 is opened and ethanol is injected from the injection reservoir 23 . 1 as a filling flow, whereby the ethanol is conveyed by the peristaltic pump 21 first to the three-way valve 20 . During the flushing procedure the three-way valve 20 is adjusted such that part of the filling flow forwarded by the peristaltic pump 21 is conveyed via the filling flow line 19 , while the remaining portion of the filling flow conveyed by the peristaltic pump 21 reaches the four-way valve 11 . Both four-way valves 11 , 18 are again adjusted such that the filling flow is lead through the shell flow lines 8 , 9 and the carrier flow line 14 . Cultivation medium flows from the pressurized container 12 into the collection container 27 to briefly inundate the lines.
After the above described flushing of the cell sorter with ethanol flushing with Aqua destillata or respectively buffer solution takes place in the same way, whereby in each case the three-way valves or respectively 22 . 2 or respectively 22 . 3 are opened.
With the above described flushing procedure excess filling flow can be diverted by the four-way valve 18 to the collection container 28 .
Following the flushing procedure the three-way valves 22 . 1 - 22 . 3 are closed and the peristaltic pump 21 is switched off.
To introduce the sorting operation the four-way valve 11 is adjusted such that the pressurized container 12 is connected to the Y piece 10 , such that the cultivation medium in the pressurized container 12 is pressed into the shell flow lines 8 , 9 on account of the excess pressure prevailing in the pressurized container 12 .
Further to this, during the sorting operation the four-way valve 18 is adjusted such that there is no flow connection between the T piece 16 and the four-way valve 18 .
The carrier flow injected by the carrier flow injection 17 then flows via the T piece 16 into the particle injector 15 , whereby biological cells are injected into the carrier flow by a further injection 29 . Next the carrier flow flows with the injected biological cells from the particle injector 15 via the carrier flow line 14 to the terminal 2 of the sorter chip.
It should also be mentioned that attached to the particle injector 15 is a temperature sensor 30 for measuring the temperature T of the particle injector 15 .
In addition to this, a tempering element 31 in the form of a Peltier element, for heating or cooling the particle injector 15 , is located on the particle injector 15 .
The heating or respectively cooling energy Q is hereby preset by a temperature controller 32 , which is connected at the inlet side to the temperature sensor 30 and resets the temperature T of the particle injector 15 to a preset nominal value.
The embodiment of the particle injector 15 illustrated in FIG. 2 will now be described hereinbelow.
The particle injector 15 has a basic body 33 made of PEEK, which can be autoclaved and thus enables easy and/or multiple sterilization.
For taking up the carrier flow the particle injector 15 has an inlet 34 with an inner thread 35 , into which a screw flange of a terminal hose 36 can be screwed, with the screw flange not being illustrated here for the sake of clarity.
For discharging the carrier flow with the injected biological cells the particle injector 15 has an outlet 37 with an inner thread 38 , in which likewise a screw flange of a terminal hose 39 can be screwed, with the screw flange of the terminal hose 39 likewise not being illustrated here for the sake of clarity.
To make mounting of both hoses 36 , 39 easier the particle injector 15 in each case has a centering aid 40 , 41 , comprising a cylindrical pick-up and bordering the inlet 34 or respectively 37 . Running between both centering aids 40 , 41 is a carrier flow channel 42 coaxially to both centering aids 40 , 41 , whereby the inner diameter of both centering aids 40 , 41 is larger by the wall thickness of both connecting hoses 36 , 39 than the inner diameter of the carrier flow channel 42 . With mounting the connecting hoses 36 , 39 the former are therefore placed in the centering aids 40 , 41 such that at the point of impact between the hoses 36 , 39 and the carrier flow channel 42 no leaks occur, which extensively prevents occlusion of the carrier flow channel 42 .
In the carrier flow channel 42 an injection channel 43 , into which an injection needle of the injection 29 can be introduced for injecting biological cells, terminates at a right angle to the carrier flow channel 42 , whereby the injection needle of the injection 29 punctures a septum 44 .
FIG. 3 shows an alternative embodiment of an injector 15 ′, which substantially matches with the above described embodiment illustrated in FIG. 2 . In the interests of avoiding repetition reference is therefore made hereinbelow to the above described description to FIG. 2 , whereby the same reference numerals are used as in FIG. 2 for corresponding parts, which are distinguished for differentiating only by an apostrophe.
A particularity of the particle injector 15 ′ comprises the inlet 34 ′ for the carrier flow being arranged on the underside of the particle injector 15 ′, while the outlet 37 ′ for the carrier flow with the injected biological cells being located on the top side of the particle injector 15 ′. The carrier flow therefore runs in the particle injector 15 ′ vertically from bottom to top, whereby the injection channel 43 ′ terminates to the side in the carrier flow channel 42 ′.
A further particularity of the particle injector 15 ′ is that the cross-section of the carrier flow channel 42 ′ tapers from top to bottom, so that the flow rate of the carrier flow in the carrier flow channel 42 ′ accordingly increases from top to bottom. Sedimentation deposits on the underside of the carrier flow channel 42 ′ are counteracted by this increase in the flow rate in the carrier flow channel 42 ′.
There is also the possibility that at the lower end of the funnel-shaped narrowing of the injection channel 43 ′ just above the carrier flow channel 42 ′ there is a valve arranged, enabling discontinuous particle feeding.
FIG. 4 shows another alternative embodiment of a particle injector 15 ″, which likewise substantially matches the above described particle injector 15 shown in FIG. 2 . To avoid repetition therefore hereinbelow reference is also made to the above description to FIG. 2 , whereby the same reference numerals are used for corresponding parts, which are distinguished for differentiating only by two apostrophes.
A particularity of the particle injector 15 ″ comprises the cross-section of the injection channel 43 ″ widening upwards to its terminal opening, so that the injection needle of the injection 29 can be introduced more easily.
In addition to this, the conical narrowing of the injection channel 43 ″ also has a funnel function, since the particles converge in the lower region of the injection channel 43 ″, so that no or only some particles remain in the injection channel 43 ″, ensuring continuous particle feeding.
The cross-sectional widening of the injection channel 43 ″ further offers the advantage that the injection channel 43 ″ has an additional injection volume in the range of 5-100 μl.
Finally, FIG. 5 shows an exemplary feeding-in aid 45 for the injection needle of the injection 29 , whereby the feeding-in aid 45 is designed as a separate component. The feeding-in aid 45 has on its underside a cylindrical section 46 with an external thread 47 , which can be screwed into a corresponding inner thread of the particle injector 15 ′ or respectively 15 ″, in order to attach the feeding-in aid 45 on the particle injector 15 ′ or respectively 15 ″.
The feeding-in aid 45 is screwed in manually via knurling 48 , arranged on an upper section of the feeding-in aid 45 .
In the feeding-in aid is a projection 49 of the injection channel 43 or respectively 43 ′, which transitions at its top side into a funnel-shaped widening 50 , to facilitate introducing the injection needle of the injection 29 .
FIG. 6 finally shows a modification of the region outlined in dashed lines in FIG. 1 , so that hereinbelow reference is made to the description to FIG. 1 to avoid repetition. In addition to this, the same reference numerals, which are distinguished to avoid repetition only by additional indices, are used for corresponding components.
A particularity of this modification comprises three particle injectors 15 . 1 - 15 . 3 being arranged successively in the carrier flow line 14 ′, so that three different particles can be injected into the carrier flow.
FIG. 7 shows a further embodiment of an inventive particle injector 51 with an inlet 52 for receiving a carrier flow and an outlet 53 for discharging the carrier flow with particles suspended therein.
The inlet 52 terminates in the particle injector 51 in an agitation chamber 54 , in which a magnetic stirring rod is located, not illustrated here for the sake of clarity. The carrier fluid in the agitation chamber 54 can therefore be agitated by a conventional magnetic stirrer, resulting in thorough intermingling of the carrier fluid with the particles suspended therein. The agitation rate is hereby selected such that the particles suspended in the carrier fluid are not damaged by the stirring procedure.
The particle injector 51 comprises a lower part 55 and an upper part 56 , whereby the agitation chamber 54 is arranged in the lower part 55 . In the mounted state the lower part 55 is connected firmly to the upper part 56 and sealed by an O ring located in between.
The particles are injected into the carrier flow via an injection channel 57 , which terminates in the agitation chamber 54 to the side near the outlet 53 ′. The injection channel 57 can hereby be closed by a septum, as already described hereinabove.
In this embodiment the inlet 52 for the carrier flow is on the underside of the particle injector 51 , whereas the outlet 53 is arranged on the top side, so that the carrier flow flows through the particle injector 51 from bottom to top.
Alternatively, however, it is also possible that the inlet 52 is arranged on the top side of the particle injector 51 , while the outlet 53 is located on the underside of the particle injector 51 , such that the carrier flow slows through the particle injector 51 from top to bottom.
Hereby, parallelizing is also possible and between the agitation chamber 54 and the outlet 53 a valve can be arranged to enable discontinuous discharge.
FIG. 8 shows a further embodiment of an inventive particle injector 58 with an inlet 59 for receiving a carrier flow and an outlet 60 for discharging the carrier flow with particles suspended therein.
The inlet 59 is hereby arranged on the left side of the particle injector 58 , while the outlet 60 is located on the underside of the particle injector 58 . The carrier flow is therefore deflected down into the particle injector 58 by 90°.
For particle injection the particle injector 58 has an injection terminal 61 , arranged on the top side of the particle injector 58 and closed by a septum 62 . The septum 62 is penetrated by an injection needle for injecting particles into the carrier flow.
Located under the septum 62 in the particle injector 58 are a cylindrical sedimentation space 63 , in which the suspended particles illustrated by hatching 64 sedimentize downwards due to gravity, and enter the carrier flow depending on the sedimentation rate. The sedimentation space 63 can however alternatively be designed conically.
FIG. 9 shows a further embodiment of an inventive particle injector 65 with an inlet 66 for the carrier flow and an outlet 67 for discharging the carrier flow with the particles suspended therein.
The inlet 66 for the carrier flow is located on the underside of the particle injector 65 , while the outlet 67 is arranged on the top side, so that the carrier flow flows through the particle injector 65 from bottom to top.
The inlet 66 is connected via a carrier flow channel 68 to the outlet 67 , whereby an injection channel 69 , which goes out from an injection terminal 70 , terminates in the carrier flow channel 68 obliquely from above, whereby the injection terminal 70 is closed by a septum 71 in the above described manner.
A particle suspension, which is distributed in the long-stretched-out injection channel 69 , is injected through the injection terminal 70 . Due to gravity the particles begin to sink. A jet, which already receives sunken and other still sinking particles and flows upwards out of the particle injector 65 , is formed by the carrier flow, which enters the particle injector 65 from below and via the narrowing of the carrier flow channel 68 , as shown. In the long-stretched-out carrier flow channel 68 the resulting carrier flow rates and injected volumes can vary, depending on length and diameter.
FIG. 10 shows a further embodiment of an inventive particle injector 72 with two laterally arranged, opposing inlets 73 , 74 for receiving two carrier flows, whereby both inlets 73 , 74 terminate in the middle of the particle injector 72 into a perpendicular cylindrical injection channel 75 .
The injection channel 75 goes from an injection terminal arranged on the top side of the particle injector 72 76 and terminates on the underside of the particle injector 72 in an outlet 77 for discharging the carrier flow with the particles suspended therein.
FIG. 11 shows a perspective illustration of a further embodiment of an inventive cuboid particle injector 78 with an inlet 79 for receiving a carrier flow and an outlet 80 for discharging the carrier flow with particles suspended therein, whereby the inlet 79 inside the particle injector 78 is connected to the outlet 80 by a carrier flow channel.
The inlet 79 is hereby located on the side of the particle injector 78 in the lower third, whereas the outlet 80 is arranged centrally on the top side of the particle injector 78 .
Situated on the front side of the particle injector 78 is an injection terminal 81 , by means of which particles can be injected into the carrier flow.
FIG. 12 finally shows an embodiment of an inventive particle injector 82 with a meandering guide for a carrier flow channel 83 between an inlet 84 and an outlet 85 .
Terminating in the meandering carrier flow channel 83 is an injection terminal 86 , via which particles can be injected into the carrier flow. Due to the narrowing and widening in the carrier flow channel 83 the sedimentizing of particles in the carrier flow channel 83 is countered, so that the suspended particles move uniformly and continuously.
The invention is not limited to the above described preferred embodiments. Rather a plurality of variants and modifications is possible, which can likewise make use of the inventive idea and therefore fall within the range of protection.
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The invention relates to a particle injector for introducing particles into a carrier flow of a microfluidic system, especially for injecting biological cells into the carrier flow of a cell sorter. The particle injector includes an inlet for receiving the carrier flow, an outlet for discharging the carrier flow including the introduced particles, a carrier flow channel which connects the inlet to the outlet, and an injection channel flowing into the carrier flow channel for introducing the particles into the carrier flow. The inventive particle injector is characterized in that the carrier flow channel has substantially no dead volume.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for interlacing a continuous multifilament yarn by passing the yarn through a yarn passageway and directing high pressure fluid from orifices onto the yarn.
Various types of apparatus are known for producing interlaced yarns, i.e., yarns possessing continuous multifilaments which have been subjected to an interlacing operation to provide the multifilaments with cohesion in place of twisting or twisting and sizing. An interlaced yarn is formed of continuous multifilaments which have been interlaced, i.e., commingled, entwined or entangled, in a disordered fashion forming "pseudoknots" in order to produce a yarn having an approximately zero overall twist. Such interlacing facilitates such down-stream textile operations as beaming, sizing, weaving, twisting, tufting, knitting, and the like.
Known and conventional yarn interlacers subject the yarn moving under relatively low tension between two yarn guides in an interlacing zone to the action of a high velocity fluid stream, usually a jet of compressed air. In practice, the jet of compressed air is directed in a plane substantially transverse to the advancing direction of the yarn.
Important considerations in the design and fabrication of a yarn interlacer include the versatility of the apparatus for processing different types of yarn and achieving a variety of interlacing objectives In known and conventional yarn interlacers, e.g., those described in U.S. Pat. Nos. 3,262,179; 3,286,321; 3,751,775; 3,828,404; and 3,889,327, the yarn undergoing interlacing is passed through a passageway of fixed and unvarying configuration with the pressurized fluid outlets similarly bearing a fixed and unvarying relationship to the yarn. The fixed geometry of such interlacers necessarily limits their ability to process different types and constructions of yarns and produce a variety of interlacing effects.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a yarn interlacer of modifiable configuration which can be readily and inexpensively manufactured.
It is a particular object of the invention to provide a modular yarn interlacer assembled from a series of plates in sandwich-like or laminate fashion, the number and specific sequence of the plates being readily altered to provide interlacers of varying configurations.
By way of meeting these and other objects of the invention there is provided a modular yarn interlacer comprising an assembly of intermediate plates which in registry cooperate to form one or more longitudinal yarn passageways, a longitudinal fluid inlet passageway, one or more fluid inlet channels connecting the fluid inlet passageway with the yarn passageway, and a pair of end blocks with the assembly of intermediate plates being positioned therebetween. The interlacer of the invention may also include one or more spacer plates which include no fluid inlet channels and/or which alter the diameter of the yarn passageway.
The modular construction of the yarn interlacer of this invention makes it possible to provide yarn processing passageways of different lengths and cross sections with the fluid inlet channels being distributed along the length of the yarn passageway in accordance with almost, any desired pattern. Thus, simple rearrangement of the number, type and positioning of the intermediate plates, each of which is placed in registry through a common alignment means, e.g., bolts extending the full length of the interlacer, permits the configuration of the interlacer to be altered for optimum interlacing of a particular yarn.
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. This invention can, however, be embodied in many different forms and the invention should not be construed as being limited to the specific embodiments set forth herein. Rather, applicant provides these embodiments so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a front view of an intermediate plate of a yarn interlacer in accordance with the present invention;
FIG. 2 illustrates, a longitudinal cross-sectional view of one arrangement of intermediate plates in a yarn interlacer in accordance with the present invention;
FIGS. 3 and 4 illustrate, respectively, a perspective view and an exploded perspective view of a fully assembled yarn interlacer in accordance with the present invention;
FIGS. 5A-5J illustrate front views of a variety of intermediate plates of a yarn interlacer in accordance with the present invention;
FIG. 6 illustrates a cross-sectional view of another embodiment of an interlacer in accordance with the present invention; and
FIGS. 7 and 8 illustrate, respectively, an exploded perspective and a cross sectional view taken along line A--A of FIG. 7 of a presently preferred embodiment of an interlacer in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, the modular construction of yarn interlacer 10 is made possible through the variable arrangement of a series of individual intermediate plates 20, specific configurations of which are shown in FIG. 2 as plates 20a, 20b, 20c and 20d, in FIGS. 3 and 4 as plates 20e, 20f, 20g and 20h and in each of FIGS. 5A-5J.
As shown in FIG. 1, an intermediate plate 20 is advantageously made up of half-plates 21a and 21b which are assembled and disassembled in clam shell fashion to facilitate string-up of the interlacer. Any suitable clamping means (not shown) may be used to secure the two sets of half-plates together. At a minimum, each intermediate plate 20 will possess one or more longitudinal yarn passageways 22, and at least one, preferably a pair of longitudinal fluid, inlet passageways 23, 24. In addition, one or more of the plates in the series will possess one or more transverse channels 25, 26 connecting fluid inlet passageways 23, 24 with yarn passageway 22. The geometries of passageways 22, 23 and 24 and channels 25 and 26 can vary considerably as can the positioning and/or the size of orifices 28 which open into the yarn passageway 22. One ordinarily skilled in the art will recognize that such geometries can be optimized for particular processes. As shown in FIG. 2, orifices 28a, 28b, 28c, 28d in successive intermediate plates 20a, 20b, 20c and 20d are positioned along the wall of yarn passageway 22 so as to form a spiral or helical pattern thereon. Other patterns can, or course, be readily obtained by simply varying the selection, number and/or arrangement of plates 20 making up intermediate section 30 of yarn interlacer 10. Aside from considerations of practicality, there is no intrinsic limit to the number or kinds of plates 20 that can be combined to provide the interlacer of this invention.
As seen in FIGS. 5A-5J, the channels formed in the intermediate plates can have a variety of patterns. FIG. 5A is a spacer plate which may be used in the interlacer of the invention, having no channel connecting fluid inlet passageway 23 with the yarn passageway 22. It should be noted that one can change the position of the orifices in the yarn passageway simply by rotating an intermediate plate 180 degrees. Thus, for example, the intermediate plate illustrated in FIG. 5C and the intermediate plate illustrated in FIG. 5F are the same, but are rotated 180 degrees. Similarly, the plates illustrated in FIGS. 5B and 5D are the same as the plates illustrated in FIGS. 5G and 5E, respectively, only rotated 180 degrees. Additionally, an advantage of having the intermediate plates divided into two half-plates is that various combinations of the halves may be assembled to provide different intermediate plate configurations. For example, the plates illustrated in FIGS. 5B-5G and 5I each include one half-plate which is of the spacer type illustrated in FIG. 5A. Also, the plate illustrated in FIG. 5J includes a top half of the type illustrated in FIG. 5H in combination with a different bottom half.
In FIG. 6 there is shown an illustrative embodiment of the invention composed of the various plates illustrated in FIGS. 5A-5I. In FIG. 6, the designations A, B, C, etc. correspond to the plates illustrated in FIGS. 5A, 5B, 5C, etc., respectively. The embodiment illustrated in FIG. 6 shows the advantageous use of spacer blocks (such as those illustrated in FIG. 5A) of varying thickness, as well as a variety of patterns which may be formed by the orifices by which fluid is introduced into the yarn passageway. Thus, for example, a spiral or helical pattern is formed along the yarn passageway by stacking the plates shown in FIGS. 5B-5H in sequence alternating with spacer plates of the type shown in FIG. 5A. As another example, an elongated horizontal jet of fluid is formed by placing several plates of the type illustrated in FIG. 5C in side-by-side relationship. An elongated vertical jet of fluid is created in the yarn passageway by employing the plate illustrated in FIG. 5I.
In FIGS. 7 and 8 there is shown a presently preferred embodiment of the invention composed of plate 20i and end blocks 50 and 51. The embodiment also illustrates the advantageous use of guide pieces 61 at entrance and exit ends of yarn passageway 22. Guides 61 prevent the abrasion of end blocks 50 and 51 by the moving yarn and reduce yarn fraying. The guide pieces may also be designed to advantageously position the yarn within the yarn passageway 22 to obtain a desired interlacing effect.
When assembling intermediate plates 20 possessing different diameters for one of the passageways therein, such passageway in the assembled intermediate section of the yarn interlacer will vary in diameter along its length. In this manner, the passageway, e.g., yarn passageway 22, can be made to abruptly or progressively increase, then decrease, in diameter along its length or a portion thereof.
Plate 20 can be manufactured from any suitable material, e.g., mild steel, stainless steel, brass, aluminum, plastic, etc. The plates and their various passageways and channels can be formed by any suitable manufacturing technique including die cutting, punching, stamping, drilling, etching, machining, electric discharge machining, molding, etc., or combinations thereof. Any suitable means may be employed to align intermediate plates in precise registry with each other and to maintain the assembled plates and their associated end blocks 50 and 51 in a tight fitting relationship. Thus, e.g., the intermediate plates and the end blocks can possess a series of evenly spaced apart apertures 29 which, in the assembled yarn interlacer, provide thruways accommodating terminallythreaded aligning bolts, or rods, 56. The bolts 56 extend beyond each end of the apparatus a sufficient distance to receive locking nuts 57.
The overall dimensions of the intermediate plates and end blocks can vary considerably according to the dimensions suitable for the process where the invention is used. In general, the plates and end blocks may have the same, or substantially the same, planar dimensions, e.g., from about 0.75 to about 1.5 inches in width and about 0.75 to about 1.5 in height. The plates can possess the same or different thicknesses, e.g., from about 0.015 to about 0.1 inches and the overall length of the fully assembled yarn interlacer can vary in the usual case from about 0.75 to about 2.0 inches, with a diameter ranging from about 0.1 to 0.3 inches.
End block 50 possesses ducts 52 and 53 (see FIG. 4) for receiving fluid inlet conduits 54 and 55 (see FIG. 3), respectively. Both end blocks possess passageways which cooperate with passageways 22 in intermediate plates 20 to form a single longitudinal yarn passageway. It should be understood that the yarn passageway 22 in end blocks 50 and 51 may be flared to form a converging/diverging configuration when assembled. It should also be understood that a pair of guide plates (not shown) which are made from a material which offers a minimum amount of friction against the yarn or fibers so as to reduce the possibility of yarn fraying may be used in lieu of guides 61 (FIG. 8). These plates are advantageously positioned adjacent to end blocks 50, 51 to protect the yarn as it enters and exits the ends of the yarn passageway. The holes through these guide plates have a diameter somewhat smaller than that of yarn passageway 22 to inhibit the yarn from being abraded by or abrading the interlacer. Suitable materials for these optional guide plates include, but are not limited to fluroplastics (like Teflon®), polished chrome platings, glass and ceramics.
In operation, yarn 40 advances under slight tension from a supply source into entrance end 60 of yarn passageway 22, passing therethrough to emerge at the other end of the interlacer unit (see FIG. 3). A pressurized fluid such as air or steam supplied to fluid inlet passageway 23 through conduit 54 (see FIG. 3) is directed by channels 25, 26 through orifices 28 against yarn strand 40 thereby effecting the interlacing of the yarn. Elevated pressure within yarn passageway 22 is relieved at either end thereof. The fluid introduced through orifices 28 exits the interlacer via either end of yarn passageway 22.
A major benefit provided by the modular approach to interlacer construction of the present invention is the ability to easily assemble a large variety of orifice configurations. As illustrated in FIGS. 1, 2, 6 and 7 the plates of the present invention can be stacked to form complex orifice arrangements that would be very difficult to machine conventionally Because interlacer design is largely empirical, the present invention provides the benefit of allowing evaluation of a large number of configurations using a limited number of parts.
The foregoing description is to be considered illustrative rather than restrictive of the invention, and those modifications which come within the meaning and range of equivalence of the claims are to be included therein.
|
A yarn interlacer is provided which, being of modular construction, possess a greater versatility for processing yarns of different types.
| 3
|
FIELD OF THE INVENTION
[0001] The invention relates to arrangements for receiving plural information flows. A possible field of use of such arrangements are so-called Multiple Input Multiple Output (MIMO) antenna systems.
DESCRIPTION OF THE RELATED ART
[0002] MIMO systems represent a promising solution for improving the capacity (throughput) and reliability (coverage range) of wireless communication systems.
[0003] In a MIMO system the transmitter is equipped with n T antennas and the receiver with n R antennas operating at the same time on the same frequency. A possible transmission mode of MIMO systems is the so-called spatial multiplexing (SM) technique based on the transmission of different data streams across the n T antennas with the goal of increasing the overall throughput. Recent information theory results have revealed that a richly scattered multi-path wireless channel is capable of providing a huge capacity. In the presence of MIMO-SM transmission mode, the multi-path environment can be exploited by transmitting simultaneously on the same frequency different data streams on different transmitting antennas providing a K-fold capacity increase, where K is the minimum between the number of transmitting antennas and the number of receiving antennas, i.e. K=min(n T , n R ) with the constraint that n R ≧n T .
[0004] A block diagram of an exemplary MIMO system operating in a spatial multiplexing (SM) mode is shown in FIG. 1 . There, a transmitter TX is shown which transmits a plurality of information flows towards a receiver RX over a channel C.
[0005] The transmitter TX can be thought of as a serial-to-parallel converter (S/P) or, equivalently, a time de-multiplexer. Supposing that every antenna is able to carry a data signal with a throughput equal to S, the overall throughput of the data signal x at the input of the MIMO transmitter TX is equal to n T ·S, that is n T times larger than the throughput S carried by every single antenna. The spatial multiplexing effect across the multiple transmitting antennas introduced by the MIMO-SM transmitter leads to these data streams being mixed up in the air (i.e. in the “channel” C). If n R ≧n T the output signal y can be recovered at the receiver RX by means of suitable signal processing algorithms. MIMO systems also offer a significant diversity advantage and thus they can improve the coverage range with respect to single antenna systems (SISO) by exploiting both transmit and receive antenna diversity.
[0006] The propagation channel C from the transmitter TX to the receiver RX can be modeled, for each multi-path component, by means of a channel matrix H of complex channel coefficients with size n R ×n T . The larger spectral efficiencies (high throughputs) that can be achieved with MIMO channels are based on the assumption that a rich scattering environment provides independent transmission paths from each transmit antenna to each receive antenna. Therefore, for single-user systems, a transmission and reception strategy that exploits this structure will achieve, with the minimum number of transmitting and receiving antennas K=min(n T , n R ), a linear increase of the transmission rate for the same bandwidth with no additional power expenditure over a single antenna system. This capacity increase requires a scattering environment such that the channel matrix between transmit and receive antenna pairs has full rank and independent entries and that perfect estimates of its coefficients are available at the receiver. Performance of a MIMO system operating in a SM mode, in terms of throughput versus signal to noise plus interference (SINR) ratio, will thus depend on the properties of the channel matrix.
[0007] The exemplary SM technique considered here is based on digital signal processing operations that are performed by the receiver, at base-band level, and, in principle, is essentially independent of the electromagnetic characteristics of the receiving antennas (provided they have omni-directional radiation patterns). In the case in question, the number n R of receiving antennas is assumed to be larger or at most equal to the number n T of the transmitting antennas or equivalently the number of the transmitted spatial streams. In comparison to conventional MIMO receivers with n R =n T , those MIMO receivers having a number n R of receiving antennas higher than the number n T of multiple spatial streams provide a higher performance level, in terms of throughput versus signal to noise plus interference (SINR) ratio. This entails however a cost in terms of additional complexity due to the n R −n T additional receivers and more complex base band (BB) algorithms.
[0008] WO-A-03/073645 describes a radio communications device comprising three or more diverse antennas and either a plurality of transmit chains or a plurality of receive chains, and wherein there are fewer transmit or receive chains than antennas. The radio communications device is arranged to provide multiple-input multiple-output (MIMO) communications with the advantage that increased data rates can be achieved in addition to cost and space reduction. The antennas employed can have directional radiation patterns with the further advantage of providing higher levels of signal-to-interference plus noise ratios (SINR) when employed in a cellular network. The radio communications device comprises a selector arranged to select for each receive chain or for each transmit chain any one of the antennas for use in conjunction with that receive or transmit chain as, for example, in a switched antenna selection scheme.
[0009] WO-A-06/052058 describes a method for enhancing performance of a MIMO system employing a space-time coding (STC) scheme, MIMO-STC, in conjunction with transmit antenna selection scheme. The transmitter includes N transmit antennas that are in excess of the M transmit antennas required for transmitting a signal to a space channel. The transmitter selects the M transmit antennas among the N transmit antennas and transmits a symbol by space-time encoding the symbol. The receiver includes M receive antennas for receiving a signal from the space channel so that it detects the transmitted information symbol by using the signal received through the receive antenna and subsequently generates a transmit antenna selection information for selecting M transmit antennas among N transmit antennas and returns the information to the transmitter.
[0010] PCT Application PCT/EP2006/011430, not yet published at the time of filing of this application, discloses a wireless communication system wherein a sub-set of RF signals received from corresponding antenna elements is selected and combined into a single RF signal. The single RF signal is processed and demodulated in a single processing chain, which comprises a RF phasing network for co-phasing the selected RF signals before combining and a processor for controlling combining and phasing in order to obtain a single RF signal having a radio performance indicator which satisfies predetermined conditions.
OBJECT AND SUMMARY OF THE INVENTION
[0011] The Applicant has observed that the need exists for arrangements for use at the receiving side of e.g. a MIMO system with a number n R of receiving antennas larger than the number n T of transmitted spatial streams wherein only n T RF receivers are required, with a consequent reduction in terms of hardware complexity.
[0012] A specific object of the invention is to provide such arrangements which can be used advantageously e.g. in a Wireless LAN (WLAN) or HSDPA (High Speed Downlink Packet Access) context while being simple and thus easy and inexpensive to produce.
[0013] The object of the invention is to provide a response to that need.
[0014] According to the present invention, that object is achieved by means of a method having the features set forth in the claims that follow. The invention also relates to a corresponding system as well a Wireless Local Area Network (W-LAN) device comprising such a system.
[0015] The claims are an integral part of the disclosure of the invention provided herein.
[0016] An embodiment of the invention is thus a method of receiving via a set of receive antennas a plurality of information flows, the method including the steps of:
deriving from at least a subset of said set of receive antennas respective RF signals, and producing from said RF signals a plurality of receive signals, each said receive signal to be demodulated to recover one of said information flows,
[0019] wherein said receive signals are produced as combinations of said RF signals having applied thereto relative phase shift weights.
[0020] In an embodiment, said respective RF signals re derived from all the receive antennas in the set.
[0021] In an embodiment, a MIMO receiver is provided which operates on the basis of the combination, at the RF level, of the signals received at the output of the n R antennas in order to generate n T RF signals at the input of the n T RF receivers.
[0022] Embodiments of the invention provide a performance level which is higher than that of a conventional MIMO receiver with n T omni-directional receive antennas while the extra complexity is limited to the additional number n R −n T of antennas and to the RF combining unit.
[0023] An embodiment of the invention is suitable to be employed in the presence of a switched beam antenna architecture where the combination of the signals received at the output of particular directional antennas can provide benefits in terms of array gain, diversity and interference rejection.
[0024] An embodiment of the invention can be employed in wireless systems transmitting multiple spatial streams as for example Wireless LAN (WLAN) compliant with the standard IEEE 802.11n, Wireless MAN (WMAN) compliant with the standard IEEE 802.16e and the HSDPA-MIMO system proposed in 3GPP Release 7.
BRIEF DESCRIPTION OF THE ANNEXED DRAWINGS
[0025] The invention will now be described, by way of example only, with reference to the enclosed figures of drawing, wherein:
[0026] FIG. 1 has been already described in the foregoing,
[0027] FIGS. 2 a to 2 c show exemplary antenna configurations,
[0028] FIG. 3 is a schematic representation of a switched beam antenna system,
[0029] FIG. 4 is a schematic representation of a RF phasing circuit,
[0030] FIGS. 5 and 6 are further schematic representations of RF phasing circuits,
[0031] FIGS. 7 and 8 are schematic representations of switched beam antenna systems, and
[0032] FIG. 9 shows an exemplary antenna arrangement with directional antennas.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] This detailed description presents an exemplary method and a related device for the implementation of a MIMO-SM receiver that, while including a number n R of receiving antennas larger than the number n T of transmitted spatial streams, may require only n T RF receivers with a consequent reduction in terms of hardware complexity. The exemplary architecture described herein may be based on the combination, at the RF level, of the signals received at the output of the n R antennas in order to generate n T RF signals at the input of the n T RF receivers.
[0034] The n R −n T redundant antennas at the receiver may be used to collect different versions of the n T transmitted spatial streams that can be combined, at the RF level, with suitable weighting factors, in order to generate an equivalent channel matrix H with good properties for the transmission of multiple spatial streams.
[0035] The minimum Euclidean distance of the received constellation may be a good parameter for determining the performance of a MIMO system operating in SM mode. A description of the related theory is provided by R. W. Heath and A. J. Paulraj in: “Switching Between Diversity and Multiplexing in MIMO Systems” published on IEEE Transactions on Communications, Vol. 53, No. 6, June 2005.
[0036] In the following, an exemplary MIMO-SM system with two transmitting antennas and two receiving antennas will be considered, so that n R =n T =2.
[0037] In this particular example the channel matrix H has the following expression
[0000]
H
=
(
h
11
h
12
h
21
h
22
)
(
1
)
[0000] where the coefficients h ij with i=1,2 and j=1,2, in the case of omni-directional receiving antennas and a propagation scenario rich of scattering objects, are statistically independent complex zero mean Gaussian processes with an envelope having a Rayleigh probability density function and unitary variance. The minimum Euclidean distance of the codebook (or constellation) at the receiver (i.e. the codebook constructed when the channel operates on each codeword) may be a good performance indicator of a MIMO-SM system because, assuming maximum likelihood detection, the conditional error probability, given a channel realization, can be determined by the distance properties of the codebook at the receiver.
[0038] If s =[s 1 , s 2 ] T denotes a codeword comprised of two QPSK symbols s 1 and s 2 respectively transmitted by the first and the second antenna of a 2×2 MIMO-SM system and r =[r 1 , r 2 ] T denotes the corresponding codeword of symbols received respectively by the first and the second antenna, the following relationship applies:
[0000] r =H· s + n (2)
[0039] where n =[n 1 , n 2 ] T is the contribution of the thermal noise samples n 1 and n 2 at the input of the first and the second antenna, respectively. These noise samples can be assumed to be gaussian with zero mean and variance equal to N 0 . For convenience every transmitted signal codeword is assumed here to be normalized in order to have unit energy E s so that E s =∥s 1 ∥ 2 +∥s 2 ∥ 2 =1 and the channel H is assumed to be perfectly known at the receiver (via training symbols).
[0040] The following description will refer to a MIMO decoder based on a maximum likelihood (ML) algorithm and performance of the MIMO-SM system will be assumed to be indicated by the raw Bit Error Rate (BER) as a function of the signal-to-noise plus interference ratio (SINR) at each receiving antenna. Those skilled in the art will appreciate that any other MIMO decoder, such as e.g. a MIMO decoder based on maximum-a-posteriori algorithm, or any other performance indicator may be used.
[0041] The paper by R. W. Heath and A. J. Paulraj already cited in the foregoing shows that the error probability on the received codeword r conditioned to a particular channel realization H, denoted as P(error/H), is upper bounded by the following expression
[0000]
P
(
error
/
H
)
≤
(
2
M
-
1
)
erfc
(
E
S
2
N
0
d
min
,
r
2
(
H
)
)
(
3
)
[0000] where M is the overall number of bits carried by the MIMO-SM system for each possible transmitted codeword (e.g. with M equal to 4 for a system with n T =2 and a QPSK modulation) and d min,r 2 (H) is the squared minimum Euclidean distance of the received codebook. In the particular case of QPSK modulation and n R =n T =2 transmitting and receiving antennas the squared minimum Euclidean distance of the received codebook d min,r 2 (H) conditioned to the channel matrix H can be computed as detailed in the following.
[0042] If one considers two transmitted codewords s i and s j such that s i ≠ s j . The squared Euclidean distance between two possible transmitted codewords s i and s j at the receiver is given by
[0000] ∥H·( s i − s j )∥ 2
[0043] The minimum squared Euclidean distance at the receiver can be found by minimizing this difference over all possible codewords and can be expressed as
[0000]
d
min
,
r
2
(
H
)
=
min
i
,
j
i
≠
j
r
_
i
-
r
_
j
2
=
min
i
,
j
i
≠
j
H
·
(
s
_
i
-
s
_
j
)
2
(
4
)
[0044] The impact of the minimum Euclidean distance d min,r 2 (H) of the codebook (or constellation) at the receiver on the performance of a MIMO-SM system in terms of raw BER as a function of the signal to interference plus noise ratio (SINR) measured at each receiving antenna can be evaluated on the basis of the following conditional probabilities:
[0000] Raw BER 1 =P{error| 0.0 <d min,r 2 ( H )≦0.5}
[0000] Raw BER 2 =P{error| 0.5 <d min,r 2 ( H )≦1.0}
[0000] Raw BER 3 =P{error| 1.0 <d min,r 2 ( H )≦1.5}
[0000] Raw BER 4 =P{error| 1.5 <d min,r 2 ( H )≦2.0}
[0000] Raw BER 5 =P{error| 2.0 <d min,r 2 ( H )≦2.5}
[0045] These can be obtained by conditioning the Raw BER to different values of the minimum squared Euclidean distance d min,r 2 (H) quantized over five different intervals derived from the corresponding probability density function. For higher values of the parameter d min,r 2 (H), performance in terms of raw BER exhibits a significant gain in terms of SINR with respect to the corresponding curves obtained for smaller values of d min,r 2 (H).
[0046] The minimum Euclidean distance d min,r 2 (H) can be calculated at the receiver by exploiting the knowledge of channel matrix H, which is estimated by means of reference sequences. The computation of equation (4) may however require a search over a large number of transmitted codewords, which may be prohibitive for large constellations such as 16 QAM or 64 QAM. Measuring the parameter d min,r 2 (H) at the receiver may thus turn out to be overly complex.
[0047] It is thus possible to derive an indication about the minimum squared Euclidean distance of the constellation received from the corresponding value of Raw BER measured by the baseband (BB) modules of a MIMO receiver. Moreover, by exploiting the one-to-one relationship between one particular value of the raw BER and the corresponding value of the BER decoded at the output of the channel decoder or, alternatively, the corresponding value of packet error rate (PER), it is possible to derive an indirect measure of the minimum squared Euclidean distance through the corresponding value of PER averaged over a certain number of received packets. The lower the value of PER, the higher the corresponding value of minimum squared Euclidean distance.
[0048] Measuring MIMO receiver performance in terms of PER involves the reception of several packets and may be slower than a corresponding measurement of the minimum squared Euclidean distance (which in principle can be performed instantaneously on every packet received). Moreover, the measure of PER can be performed with a negligible complexity with respect to the measure of minimum squared Euclidean distance that, on the contrary, may impact on system complexity. The throughput (T) that a MIMO receiver can achieve is directly related to the PER according to the following relationship
[0000] T=T peak ·(1− PER )
[0000] where T peak is the peak throughput achievable in the absence of errors in the received data stream. Consequently, it may also be possible to measure MIMO receiver performance in terms of the throughput (T) achievable in a particular propagation scenario. Moreover, MIMO wireless systems usually support adaptive modulation and coding techniques that adaptively change the employed modulation and coding scheme. A higher signal-to-interference-plus-noise ratio (SINR) at the receiver will translate into a higher product of the modulation order and the channel encoding rate employed and, consequently, the maximum achievable throughput T peak will be higher.
[0049] If one defines the transmission mode (TM) employed as the set of parameters, including modulation order and channel encoding rate, which determines the maximum achievable throughput T peak , an alternative way for measuring the performance of a MIMO receiver may be via the transmission mode (TM) employed in a particular propagation scenario.
[0050] For a IEEE 802.11 WLAN system, the transmission mode may correspond to a particular transmission scheme, characterized by a particular modulation scheme (QPSK, 16 QAM, 64 QAM for example) and channel encoding rate (1/2, 3/4, 5/6 for example) that determine the maximum data rate at the output of PHY layer (6, 12, 18, 24, 54 Mbps for example). New transmission modes have been introduced for a MIMO-WLAN system compliant with the standard IEEE 802.11n. Similarly, for a UMTS system the transmission mode may correspond to a particular value for the transport format (TF) that determines the maximum data rate at the output of PHY layer (e.g. 12.2, 64, 128, 384 kbps) while for a HSPDA system the transmission mode may correspond to a particular value of the channel quality indicator (CQI) that determines the maximum data rate at the output of PHY layer (e.g. 325, 631, 871, 1291, 1800 kbps).
[0051] The quality of a MIMO-SM radio link perceived by a MIMO receiver can be reasonably measured by means of a quality function Q, that depends on some physical (PHY) and MAC layer parameters such as received signal strength indicator (RSSI), Packet Error Rate (PER), MAC throughput (T) and employed transmission mode (TM), i.e.:
[0000] Q s =f ( RSSI,PER,T,TM )
[0052] Usually, the higher the value of Q s , the higher the quality of the received signal at application level. Those skilled in the art will appreciate that other quality indicators as indicated in the foregoing may be used to calculate an alternative quality function.
[0053] The function Q s may thus be used as a Radio Performance Indicator (RPI) to select the beams (i.e. the RF channels) and the RF phase shift weights to be applied. Other types of Radio Performance Indicators (RPI) may be used within the framework of the arrangement described herein. It will however be appreciated that, while being representative of the quality of the respective RF signal, such radio performance indicators as e.g. the Received Signal Strength Indicator (RSSI), Packet Error Rate (PER), Signal to Interference-plus-Noise ratio (SINR), MAC throughput (T) and employed transmission mode (TM), or any combination of the aforementioned performance indicators will be non-RF, i.e. Intermediate Frequency (IF) or BaseBand (BB) indicators.
[0054] FIGS. 2 a to 2 c show some exemplary antenna configurations including a number of receive antennas n R which will be assumed to be larger than the number n T of transmitted spatial streams (i.e. information flows). In the following, the RF signals received at the output of the n R antennas will be denoted as r i where i=1,2, . . . , n R .
[0055] Specifically, in FIG. 2 a six antennas A 1 ,A 2 , . . . , A 6 are arranged on a line. In FIGS. 2 b and 2 c , eight antennas A 1 ,A 2 , . . . , A 8 are placed equidistantly on the perimeter of a square ( FIG. 2 b ) and the perimeter of a circle ( FIG. 2 c ).
[0056] For instance, an exemplary case can be considered where the number of transmitted spatial streams n T is equal to 2 (two) and the number of receiving antennas n R is equal to 8 (eight).
[0057] In a receiving apparatus the number of RF receivers may be equal to the number of receiving antennas n R so that the base band (BB) processing unit has, as input, n R digital signals that can be exploited for improving the system performance in terms of coverage and throughput. In this case, an equivalent channel matrix H can be defined as
[0000]
H
=
(
h
11
h
12
h
21
h
22
h
31
h
32
h
41
h
42
h
51
h
52
…
h
n
R
1
h
n
R
2
)
[0000] so that the BB receiver may be a Maximum Likelihood (ML) receiver computing, with the knowledge of the signals r =[r 1 , r 2 , . . . r n R ] T received in correspondence of the transmitted unknown symbols s =[s 1 , s 2 ] T , the following metrics.
[0000] d 2 ( r , s i,j )=∥( r −H·s i,j )∥ 2 (5)
[0000] where s i,j =[s i , s j ] T is a particular codeword of the transmitted Codebook.
[0058] This first technique for exploiting the n R −n T redundant antennas may require a number of RF receivers or transceivers equal to the number n R of receiving antennas with a consequent impact on the hardware complexity of the receiver at both BB and RF level.
[0059] In order to exploit the n R −n T redundant antennas, the receiver may select a set of n T signals {A i ,A j , . . . A k } obtained at the output of n T receiving antennas and feeding the input of the n T RF receivers with the corresponding RF signals.
[0060] For exemplary purposes, one may consider the case of n R =8 and n T =2. In that case, an exemplary criterion for the selection of the pair (A i ,A j ) of receiving antennas may involve selecting the two antennas (A i ,A j ) with the highest values of received signal strength indicator (RSSI) measured by the BB processing unit. In particular, feedback signals generated by the BB processing unit may be used to control the antenna selection unit during the measurement of the RSSI from every particular beam.
[0061] A second possible criterion may involve selecting the two antennas (A i , A j ) that provide an equivalent channel matrix H
[0000]
H
=
(
h
i
1
h
i2
h
j
1
h
j2
)
[0000] with the largest squared Euclidean distance or, alternatively, with the highest value of quality function Q s in terms of throughput (T) or transmission mode (TM).
[0062] In the following, this technique will be referred to generally as MIMO-SM with antenna selection, independently from the particular criterion employed for the selection of the antenna pair (A i , A j ).
[0063] An approach for exploiting the n R −n T redundant antennas at the receiver may be based on the generation of n T signals z =[z 1 , z 2 , . . . z n T ] T by linear multiplying the vector r =[r 1 , r 2 , . . . r n R ] T of n R received signals for a combining matrix W with n T lines and n R columns
[0000]
W
=
[
w
1
,
1
w
1
,
2
w
1
,
3
…
w
1
,
n
R
w
2
,
1
w
2
,
2
w
2
,
3
…
w
2
,
n
R
w
n
T
,
1
w
n
T
,
2
w
n
T
,
3
…
w
n
T
,
n
R
]
so
that
z
_
=
W
·
r
_
(
6
)
[0064] In the exemplary case, where the number of transmitted spatial streams n T is equal to 2 and the number of receiving antennas n R is equal to 8, the matrix W has 2 lines and 8 columns.
[0065] An embodiment of a possible switched beam antenna system is shown in FIG. 3 . Specifically, a number of n R antennas A 1 ,A 2 , . . . A n R are connected to a phasing and combining network 10 , which is in turn connected to two RF receivers 20 a and 20 b . A BB processing unit 30 is then able to generate feedback signals 40 for controlling the network 10 , to perform an analysis of the signals currently received from the RF receivers 20 a and 20 b , and to select the most suitable antennas. Those skilled in the art will appreciate that also a dedicated control unit may be used in order to avoid modifications of the BB processing unit 30 . Such a control unit may e.g. read the measurements provided by the BB processing unit 30 and control the feedback signals 40 .
[0066] Generally, the received signals r =[r 1 , r 2 , . . . r n R ] T can be written as:
[0000] r =H· s + n (7)
[0000] where n =[n 1 , n 2 , . . . n n R ] T is the vector of noise and interference samples at the input of every receiving antenna with components n i with i=1,2, . . . n R that are supposed to be spatially white complex gaussian random variables with zero mean and variance equal to N 0 . By combining equation (7) and (6) follows that
[0000] z =W·H· s +W· n =G· s + m (8)
[0000] where G is a matrix with n T lines and n T columns given by the product of the combining matrix W and the channel matrix H and m =[m 1 , m 2 , . . . m n R ] T is the vector obtained by multiplying the vector of noise and interference samples n for the combining matrix W. Given a certain channel matrix H the basic idea consists in selecting the combining matrix W in order to obtain an equivalent channel matrix G with good properties in terms of minimum Euclidean distance of the received codebook d min,r 2 (G) or alternatively with higher value of quality function Q, in terms of throughput (T) or transmission mode (TM).
[0067] Moreover, when adopting this approach, by introducing some constraints on the values of the coefficients of the combining matrix W, the computation of the n T signals z =[z 1 , z 2 , . . . z n T ] T can be directly performed at the RF level with consequent savings in terms of hardware complexity; in this particular case, the number of required RF receivers is only equal to n T .
[0068] Assuming that every coefficient w i,j with j=1,2, . . . n R and i=1,2, . . . n T of W has unitary module and phase equal to φ i,j the product of the vector r =[r 1 , r 2 , . . . r n R ] T by a particular line w i =[w i,1 , w i,2 w i,3 . . . w i,n R ] T of the matrix W may be implemented by means the circuit shown in FIG. 4 .
[0069] Specifically, such a circuit may include a set of RF phasing networks 12 , which are connected to the respective antennas A i ,A 2 , . . . A nR and to a common combiner 14 .
[0070] In the exemplary case, the phasing and combining network 10 of FIG. 3 could be implemented by two of these circuits, which would then provide the signals to the RF receivers 20 a and 20 b.
[0071] A further simplification of the RF phasing network of FIG. 4 can be obtained by assuming that the phase φ i,j of the weighting coefficient w i,j can assume only particular quantized values.
[0072] Assuming that the phase φ i,j of the coefficient w i,j can take values in the set {0, π/2, π, 3/2 π}, the corresponding multiplication of the received signal r i for the coefficient w ii can be obtained by means of the circuit shown in FIG. 5 , including a number of RF delay lines 52 , 54 , 56 , 58 with different lengths.
[0073] It will be appreciated that, for the purposes of this description, a unitary real coefficient w i,j with φ i,j equal to zero will in any case be considered as a particular case for a phase shift weight.
[0074] In a corresponding embodiment as shown in FIG. 5 , the “delay” line 52 will thus be a line avoiding (i.e. exempt of) any phase shift, while the delay lines 54 , 56 and 58 generate phase shifts of 90°, 180° and 270°, respectively.
[0075] An arrangement including six RF switches SW 1 , SW 2 , . . . SW 6 will permit, by adequately setting the switches, to selectively obtain any one of the four values of phase shift in the set {0, π/2, π, 3/2π}.
[0076] The exemplary processing arrangement just described thus includes at least one RF delay line 54 to 58 to apply a phase shift weight (W) to a respective RF signal r 1 , . . . , r nR derived from the receive antennas. In the embodiment shown, the processing arrangement thus includes at least two propagation paths 52 to 58 for the RF signal r 1 , . . . , r nR . At least one of these propagation paths 52 to 58 includes a said delay line (this is the case for the paths 54 to 58 ) with a different delay value. The switching elements SW 1 to SW 6 are operable to selectively direct the respective RF signal r 1 , . . . , r nR to the propagation paths 52 to 58 in order implement a different phase shift weight. One of the propagation paths, namely the path indicated by reference numeral 52 is exempt of any delay line (i.e. implements a phase shift weight equal tozero).
[0077] Implementing RF delay lines providing a specified phase shift and RF switches for selective connection thereof is well known in the art, which makes it unnecessary to provide a more detailed description herein.
[0078] The RF multiplier circuits of FIG. 4 can be simplified by assuming that the phase φ i,j of the weighting coefficient w i,j can assume only two particular quantized values in the set {0, π}. The corresponding multiplication of the received signal r i for the coefficient w i,j can thus be obtained by means of the circuit shown in FIG. 6 .
[0079] Specifically, in this arrangement only the delay lines 52 (with no phase shift proper) and 56 and two switches SW 1 and SW 2 are required to obtain the RF multiplication.
[0080] A simplification of the overall receiver architecture can be obtained by supposing that, in every line of the combining matrix W, only n T −1 coefficients w i,j have unitary module and phase φ i,j quantized e.g. over 4 or 2 different values, one coefficient is equal to 1, and the remaining n R −n T coefficients are equal to zero.
[0081] In this particular case an additional constraint may be introduced by requiring that, in every column of the combining matrix W only one coefficient w i,j with j=1,2, . . . , n R has a module equal to 1. This means that each one of the n R signals received contributes only once to the combination.
[0082] For example, the combining matrix W may have the following structure
[0000]
W
=
[
0
,
0
,
0
,
w
1
,
A
,
0
,
0
,
w
1
,
B
,
0
0
,
w
2
,
C
,
0
,
0
,
0
,
w
2
,
D
,
0
,
0
]
[0000] with the following conditions for the four coefficients different from zero:
[0000] w 1,A =1
[0000] w 2,C =1
[0000] w 1,B =w 1 =exp( jφ 1 ) with φ 1 ε{0, π} or
φ 1 ε{0,π/2, π, 3/2π}
[0000] w 2,D =w 2 =exp( jφ 2 ) with φ 2 ε{0, π} or
φ 2 ε{0, π/2, π, 3/2π}
[0085] Specifically, the positions of the coefficients w 1,A and w 1,B in the first line of the combining matrix W determine, among the n R =8 signals r =[r 1 , r 2 , . . . r n R ] T received from the antennas A 1 ,A 2 , . . . A 8 , those signals r A and r B that are combined through the RF multiplication for the weighting coefficient w 1,B in the following denoted as w 1 .
[0086] In a similar way the position of the coefficients w 2,C and w 2,D in the second line of the combining matrix W determines the signals r C and r D that are combined through the RF multiplication for the weighting coefficient W 2,D in the following denoted as w 2 .
[0087] Finally, the constraint requiring that in every column of the combining matrix W is only one coefficient w i,j with j=1,2, . . . , n R that has a module equal to 1, corresponds to combining, at RF level, two RF signals r A and r B , whose weighted sum feeds the first RF receiver, that are different from the corresponding two RF signals r C and r D that are combined at RF level and whose weighted sum feeds the second RF receiver.
[0088] FIG. 7 shows schematically a possible embodiment of a switched beam antenna system for the exemplary case of n R =8 and n T =2. Specifically, the signals r =[r 1 , r 2 , . . . r n R ] T received from the antennas A 1 ,A 2 , . . . A 8 are connected to a switching network 122 , which provides the signals r A , r B , r C and r D . The switching network 122 may be set e.g. through the BB processing circuit 30 , which analyses the quality function Q s and provides the information about the signals r A , r B , r C and r D which are selected.
[0089] The signals r A and r B are then processed by multiplying them by the respective coefficients of the matrix W, to be then combined in a combiner 14 a and provided to the first RF processing chain 20 a . Specifically, no multiplication is necessary for the signal r A , because the coefficient w 1,A is equal to 1. Instead the signal r B is multiplied with the coefficient w 1 (i.e. w 1,B ) by a first RF phasing network 124 a.
[0090] Similarly, only the signal r D may be multiplied with the coefficient w 2 (i.e. w 2,D ) by a second RF phasing network 124 b , and the weighted signals are combined in a combiner 14 b and provided to the second RF processing chain 20 b.
[0091] Applicants verified that this condition ensures that the equivalent channel matrix G has good properties in terms of minimum Euclidean distance of the received codebook and consequently also in terms of in terms of throughput (T).
[0092] The operations performed by the MIMO wireless receiver or transceiver with redundant antennas shown in FIG. 7 are therefore the following:
determine, among the n R =8 received signals, the 4 signals r A , r B , r C and r D according to a first criteria, and determine the values of the phases of the 2 weighting coefficients w 1 and w 2 according to a second criteria.
[0095] The final goal is to maximize a certain quality function Q s that can be measured by the receiver in terms, for example, of received signal strength indicator (RSSI), Packet Error Rate (PER), MAC throughput (T) and employed transmission mode (TM) or in terms of a suitable combination of the aforementioned performance indicators so that the first criteria for the selection of the signals r A , r B , r C , and r D together with the second criteria for the selection of the weighting coefficients w 1 and w 2 should be chosen with the goal of maximizing a quality function Q s .
[0096] Exemplary embodiments of criteria for the selection of the signals r A , r B , r C , and r D are provided in the following. In the particular case of propagation scenarios without interference from the neighboring cells, where thermal noise is the main limiting factor, it is possible to select the four signals r A , r B , r C and r D with the higher values of received signal strength indicator (RSSI) measured by the BB processing unit 30 .
[0097] On the contrary, for propagation scenarios with a high level of interference it is possible to select the 4 signals r A , r B , r C and r D with the highest value of signal-to-noise plus interference ratio (SINR) measured by the BB processing unit 30 . The signal-to-noise plus interference ratio (SINR) can be measured, for example, as difference of subsequent measures of RSSI obtained first on the useful transmitter and then on the interfering transmitter. This approach is not very precise when the transmissions of the reference beacon channels of the useful and of the interfering transmitters present a certain overlap in time.
[0098] Alternatively, it is possible to select the four signals r A , r B , r C and r D providing the higher values of throughput (T) measured by the BB processing unit 30 .
[0099] After having selected the four signals r A , r B , r C and r D it is possible to optimize the values of the coefficients w 1 and w 2 through an exhaustive search driven by a certain performance indicator provided by the BB processing unit 30 such as the throughput (T) of the radio link.
[0100] In case of coefficients w 1 and w 2 quantized over two different values four different values of the aforementioned performance indicators are computed, while, in the case of coefficients quantized over four different values, sixteen different values of the performance indicator are computed and the coefficients w 1 and w 2 providing the highest value of the performance indicator are selected.
[0101] Another exemplary approach involves selecting the four signals r A , r B , r C and r D jointly with the four or sixteen 16 values of the coefficients w 1 and w 2 through an exhaustive search driven by a certain performance indicator provided by the BB processing unit 30 , such as the throughput (T) of the radio link. This approach may require a longer computational time but provides the optimal combination of the signals received and the weights that maximize the performance indicator considered.
[0102] In the particular case where the number of transmitted spatial streams n T is equal to two and the number of receiving antennas n R is equal to eight, the overall number of combination of the signals r A , r B , r C and r D with the values of the coefficients w 1 and w 2 is equal to 6720 for coefficients w 1 and w 2 quantized over 2 values and to 26880 for coefficients w 1 and w 2 quantized over 4 values. Under these assumptions an exhaustive search may not be feasible for most applications.
[0103] Possible simplifications of the switching network 122 for selecting the signals r A , r B , r C and r D can be envisaged in order to reduce the time for performing the exhaustive search.
[0104] In FIG. 8 shows an exemplary simplified switching network where only some particular combinations of the signals received by the different beams can be provided to the two RF processing chains 20 a and 20 b.
[0105] Specifically, the switching network 122 of FIG. 7 may be implemented e.g. by means of four switches. A first switch 122 a may select the signal r A among the signals provided from the antennas B 6 and B 8 . Similarly the switches 122 b , 122 c , 122 d may select the signal r B , r C and r D among the signals provided from the antennas B 2 and B 4 , B 5 and B 7 , and B 1 and B 3 , respectively.
[0106] In the exemplary implementation of the switching network shown in FIG. 8 , the overall number of combination of the signals r A , r B , r C and r D with the values of the coefficients w 1 and w 2 is equal to 64 for coefficients w 1 and w 2 quantized over 2 values and to 256 for coefficients w 1 and w 2 quantized over 4 values so that the search procedure is greatly simplified at the cost of a slight reduction of the system performance due to non exhaustive search procedure of the received signals.
[0107] The technique proposed for the reception of multiple spatial streams with redundant antennas can be employed in the presence of receiving antennas with omni-directional radiation patterns or alternatively in the presence of directional antennas with the further advantage of introducing a beneficial effect of spatial filtering (through the selection of four out of eight directional receiving antennas) that can increase system performance in the presence of a propagation scenario limited by interferers that are not spatially white.
[0108] The most common antenna types for WLANs have omni-directional radiation patterns. Omni-directional antennas propagate RF signals in all directions equally on a horizontal plane (azimuth plane). The gain achieved with an omni-directional antenna can somehow not be sufficient to reach certain coverage ranges. Higher gain values can be obtained when adopting a directional antenna, which is able to focus the transmitted and received RF energy in a particular direction thus achieving higher coverage ranges.
[0109] Moreover, in order to achieve an improvement both in terms of coverage and throughput, the spatial domain of the propagation environment can be exploited by adopting multiple antennas. Such systems increase the information available at the receiver end by means of appropriate signal processing techniques, thus reducing the impairments such as multi-path interference introduced during the transmission over the propagation channel. The exploitation of multiple directional antennas can lead to good performance in terms of throughput and coverage range.
[0110] In the particular case of directional antennas, the design of the antenna system has to take into account that the received signals arrive from all possible directions. In particular the Angle of Arrival (AoA) in the azimuth plane may take all the possible values between 0 and 360 degrees due to the presence of many scattering objects surrounding the receiver.
[0111] The AoA distribution in the elevation plane depends on the transmitter position. The transmitters are generally placed in the centre of the room or fixed to a wall or to the ceiling in order to provide maximum coverage. It is then reasonable to assume the AoA in the elevation plane is concentrated around the horizontal direction with an angular spread lower than 180 degrees.
[0112] The top view of a possible multiple directional antenna system is shown in FIG. 9 in the particular case of N=8 directional antennas B 1 , B 2 , . . . B 8 (placed on the vertexes of a regular octagon circumscribed by a circumference).
[0113] Experimental results have been obtained by the Applicant, i.a. with reference to three different receiver architectures, namely:
MIMO 2×2: the basic reference system, equipped with 2 omni-directional antennas that feed 2 RF receivers at the receiver end, MIMO 2×8 with selection of 2 directional antennas, where the receiver selects (among the 8 available receiving antennas) a suitable pair of antennas and feeds their signals to the input of 2 RF receivers. The selection of the 2 antennas is carried out by referring to the two highest Received Signal Strength Indicator (RSSI) values, and MIMO 2×8 with RF combination of 4 directional antennas, where the receiver selects (among the 8 available receiving antennas) two pairs of signals feeding the input of the 2 RF receivers. The 4 signals are selected as follows. First the selection of 4 antennas is carried on by determining, among the 8 signals received by the available antennas, the 4 signals that maximize a certain performance indicator (e.g. RSSI in a noise-limited scenario, SINR in an interference-limited scenario). Subsequently the receiver determines the appropriate phase values of the 2 weighting coefficients that maximize the same performance indicator value for the combined signals. The architecture is shown in FIG. 8 .
[0117] Four different propagation scenarios were used to evaluate system performance. These four scenarios refer to different propagation environments that are all characterized by the presence of a transmitter (TX) position and a receiver (RX) position, by two separate clusters of scatterers. All the scenarios had the same Angle of Arrival (AoA) and Angle of Departure (AoD) values but have different Angle Spread (AS) values. The angle spread values were subsequently reduced from Case 1 to Case 4, this leading to less scattered environments thus achieving higher correlation conditions. In the two first scenarios a richly scattered propagation leads to low correlation, and in the last case poorly scattered propagation leads to high correlation.
[0118] Results were obtained, in the particular case of n R =8 and n T =2, by employing the directional antenna system as shown in FIG. 9 and the architecture of the MIMO wireless transceiver with redundant antennas shown in FIG. 8 .
[0119] Performance of these two 2×8 MIMO antenna systems were compared with that of a conventional 2×2 MIMO antenna system, with specific reference to a propagation scenario where the limiting factor is the interference generated by the other users (access point or clients), which were assumed to be uniformly distributed in the spatial domain (spatially white).
[0120] The results demonstrate that the enhancement in performance, expressed in terms of raw BER, is approximately 6 dB in the range of interest. This value is slightly reduced (to 5 dB) when the propagation conditions are such that the reduced angle spread leads to higher correlation of the received signals.
[0121] The results show an even higher gain in performance in the case of spatially colored interferers.
[0122] Without prejudice to the underlying principles of the invention, the details and the embodiments may vary, even appreciably, with reference to what has been described by way of example only, without departing from the scope of the invention as defined by the annexed claims.
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In a communication system, such as a Multiple Input Multiple Output system operating in a spatial multiplexing mode, for use, e.g., in a WLAN or HSPDA device, a plurality of information flows are received via a set of receive antennas by deriving from at least some, and possibly all, of the receive antennas, respective RF signals, and producing from the RF signals thus derived, a plurality of receive signals, each receive signal to be demodulated to recover one of the information flows transmitted. The receive signals are produced as combinations of the RF signals having applied thereto relative RF phase shift weights.
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CROSS REFERENCE TO RELATED APPLICATION
This application is related to copending application U.S. Ser. No. 72,542 filed Sept. 4, 1979, in the names of Edward J. Reilly and Glenn L. Williams, the same inventors of the present invention and with the same assignee.
BACKGROUND OF THE INVENTION
The present invention relates to thermal array imaging, printing or recording devices and is more particularly directed to a protection method and apparatus to prevent overheating of the thermal array device.
It is known in the art to fabricate thermal recording devices having imaging stylii arranged in a linear array. Such devices typically are comprised of a plurality of stylii which are formed by disposing electrically resistive material on an insulating substrate to form a plurality of individual stylus in a single row. These stylii are electrically connected to driver circuits. Each stylus is selectively energized by the driver circuits to produce Joule heat. When the stylii are brought into contact with or suitable proximity with thermally sensitive imaging medium, each energized stylus makes a mark on the medium. The stylii typically are spaced to a density of 100 stylii per inch and may require as much as one watt of power to raise the stylus temperature to a level suitable for imaging. Energizing the stylii at a high repetition rate can cause overheating or even burn out of the stylii. Overheating of the stylii can also cause smudging or shadows on the recording medium.
To avoid an occurence of overheating in thermal array stylii, the prior art teaches the use of various types of temperature compensation circuits. One such circuit, disclosed in U.S. Pat. No. 3,577,137 to James Brennan, Jr., uses a temperature sensor to sense the temperature of the stylii. The power applied to the stylii then is adjusted in order to reduce the heat. Such circuits require calibration and are therefore expensive to build and maintain and are also subject to reliability problems.
Another method taught by the prior art to prevent overheating of a thermal array stylii is to control the "on" time of the incoming print command. U.S. Pat. No. 4,070,587 to Takayoshi Hanakata discloses a circuit using a "one shot" control principle, so that the drive current to the thermal stylus is cut off by the "one shot" after a predetermined interval. Such circuits, however, will not protect against overheating of the thermal stylii caused by rapid repetition of the stylus drive current.
Still another way to prevent overheating is accomplished in the prior art by the use of large metal heatsinks and by air cooling. Such devices add weight to the device and are not very efficient.
OBJECTS OF THE INVENTION
An object of the invention is to provide a protection apparatus for thermal arrays which reduces the severity of heating problems known in the prior art of thermal imaging devices.
Another object of the invention is to provide such a protection apparatus which will greatly improve the efficiency of stylii temperature reduction.
Still another object of the invention is to provide a protection apparatus which enables a thermal imaging array to operate at higher data rates than was heretofore achievable.
The above objects are given by way of example. Thus, other desirable objectives and advantages achieved by the invention may occur to those skilled in the art. The scope of the invention is to be limited only by the appended claims.
BRIEF SUMMARY OF THE INVENTION
The above objects and other advantages are achieved by the present invention. An apparatus is provided for use in thermal array imaging, printing or recording devices to prevent heat build up and thermal burn out of the stylii. An incoming digital line of data comprised of individual datum positions is received. The line of data is passed by a first passing means to a second passing means and is simultaneously stored in a first storing means. The second passing means passes the line of data to a drive circuit which in turn current drives the thermal array stylii. A next line of data is received and is compared to the previous line of data in the first storing means to determine if data exist in corresponding positions. The data of the next line of data are blocked from passing through the first passing means for those positions. All other data are passed. A first storing means stores the data passed in the next line of data. A second storing means stores data for those corresponding positions between the two lines of data. The next line of data is then passed to the drive circuit by the second passing means. Another line of data is received and is compared to the line of data just passed to determine again if data exist in corresponding positions. Only the data that does not have data in a corresponding position will be passed to the second passing means by the first passing means. The second passing means will pass only that data in positions for which the second storing means has stored data in corresponding positions or for positions which is a coincidence function of one-fourth the word length frequency and one-half the datum position frequency. The sequence is then repeated for each subsequent line of data received.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a generalized embodiment of the present invention;
FIG. 2 is a circuit diagram showing an embodiment of the present invention;
FIG. 3 is a signal waveform representation for illustrating the operation of the embodiment shown in FIG. 2;
FIG. 4 is a print out representation for illustrating the operation of the embodiment shown in FIG. 2;
FIG. 5 is a circuit diagram showing another embodiment of the present invention; and
FIG. 6 is a dot pattern representation for illustrating the overlap phenomena that occur in thermal printers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description of the invention follows, referring to the drawings in which like reference numerals denote like elements of structure in each of the several Figures.
In this application, the word "HIGH" is used, as is known in the art, to represent a digital voltage level. A digital HIGH in this application will also be designated by the numeral "1" and will be referred to as a "logic state 1". The word "LOW" is used, as is known in the art, to represent a different, lower digital voltage level. A digital LOW in this application will also be designated by the nuneral "0" and will be referred to as a "logic state 0". The voltage levels that define a digital HIGH or a digital LOW will depend on the type of digital devices used. For example, if Transistor-Transistor Logic (TTL) is used, a digital LOW will typically be from 0.0 to 0.8 volts d.c. and a digital HIGH will be from 2.0 to 5.5 volts d.c.
FIG. 1 is a block diagram showing a generic embodiment of the apparatus according to the present invention. Print data is generated by a suitable source 2 and is transmitted to a receiving means 4. The print data coming from source 2 is a series of digital lines of data which may be representative of an analog waveform. Each line of data comprises individual datum points located in individual datum positions. The number of datum positions in each line corresponds to the number of stylii in the thermal array. For example, if the thermal array has 512 stylii, there will be 512 datum positions in each line of data received. If a digital HIGH or a 1 is present in a particular datum position, this will be interpreted as data existing in the position. The line of data received is passed by a first passing means 6 to a second passing means 8. The second passing means 8 then passes the line of data received to a current drive circuit 10. The current drive circuit 10 powers the individual stylus within the thermal array 12. For example, if data exist in datum positions 21 through 50 and 176 through 200 and is passed by first passing means 6 and second passing means 8, the drive circuit 10 will power the stylii 21 through 50 and 176 through 200 in thermal array 12. A clocking means 14 is operatively connected to the passing means 6 in order to synchronize and position the line of data passing to the individual stylus to be driven. If there are 512 stylii in thermal array 12, there will be 512 clock pulses from clocking means 14 per line of data received; each clock pulse corresponding to a separate stylus to be driven.
The line of data passed by passing means 6 is also stored in first storing means 16. A next line of data is then received by receiving means 4. Each datum position in this next line of data received is compared to the corresponding datum positions in the passed line of data stored in first storing means 16. This comparison is done in first comparing means 18. If the comparing means 18 determines that data exist in corresponding datum positions, a first blocking means 20 is provided to block the passing through the first passing means 6 of data for those positions containing corresponding data in this next line of data. In the prior example, the first line of data had data in positions 21 through 50 and 176 through 200. If the next line of data has data in positions 16 through 25 and 190 through 250, the first blocking means 20 will prevent the passing of data for positions 21 through 25 and 190 through 200. The first storing means 16 will then be updated to store the datum for positions 16 through 20 and 201 through 250. This will be the data passed to second passing means 8. The effect of first storing means 16 is to delay the line of data passed by first passing means 6 by one line of data, i.e., 512 clock pulses.
A second comparing means 22 is provided which is operatively connected to both the receiving means 4 and first storing means 16. Second comparing means 22 compares the corresponding datum positions between the line of data in first storing means 16 and the next line of data received by receiving means 4. The second comparing means 22 will generate a digital signal, typically a digital HIGH when data is detected in corresponding datum positions. This signal generated by second comparing means 22 is stored in second storing means 24.
A word enable means 26 is provided that preferably generates a digital HIGH signal for a duration equal to a line of data received. For example, if a line of data is 512 clock pulses long, the word enable means 26 would preferably generate a digital HIGH signal for a time equivalent to 512 clock pulses.
A first division means 28 is operatively connected to word enable means 26 to divide the frequency of the word enable output by four. A second division means 30 is operatively connected to the clocking means 14 to divide the clocking frequency by two. A coincidence means 32 is operatively connected to both the first division means 28 and the second division means 30 to produce an EXCLUSIVE-OR output signal of the two divided frequencies. An enabling means 34 is operatively connected to coincidence means 32 and second storing means 24 to provide an enabling signal when the coincidence means 32 produces a signal or when the second storing means 24 has datum in the line of data position presently being clocked by the clocking means 14. Second blocking means 36 is operatively connected to enabling means 34 and to second passing means 8 to block the passing of datum from first passing means 6 to the current drive circuit 10 for those positions which the enabling means 34 produced a signal. The result of this invention is to reduce the effective power output and thus reduce the heat generated by the thermal array by as much as 75%. As will be discussed infra, this has no adverse effect on the resultant print out on the thermal sensitive media caused by using this apparatus.
FIG. 2 illustrates a specific embodiment of the invention. The general mode of operation of this circuit is the same as that of the generic embodiment shown in FIG. 1. The print data from source 2 is a series of lines of data comprising individual datum positions as described above. The line of data is received by AND gate 38 through one of its inputs 40. The line of data passes from the output 42 of AND gate 38 to the input 44 of FLIP-FLOP 46. Clock means 14 is connected to the clock input 48 of FLIP-FLOP 46. The FLIP-FLOP 46 positions and synchronizes the line of data received to the stylii to be driven. The output 50, of FLIP-FLOP 46 is connected to one of the inputs 52 of AND gate 54 and is also connected to input 56 of shift register 58. Clocking means 14 is also connected to the clock input 60 of shift register 58. The shift register 58 is of a type selected to correspond to the number of datum positions within a line of data. As in the previous examples, if a line of data has 512 datum positions, shift register 58 will have 512 positions. The effect of shift register 58, as will be apparent to those skilled in the art, is to delay the line of data passed by one line of data. Thus, the first datum position passed by the output 62 of shift register 58 will be synchronized with and correspond to the first datum positions of the next line of data received. An EXCLUSIVE-OR gate 64 is provided as a comparing means. The output 62 of shift register 58 is connected to the input 66 of EXCLUSIVE-OR gate 64. The incoming print data from source 2 is connected to the other input 68 of EXCLUSIVE-OR gate 64. This means that the 68 of EXCLUSIVE-OR gate 64 is connected to the input 40 of AND gate 38. The output 70 of EXCLUSIVE-OR gate 64 is connected to the other input 72 of AND gate 38. It will be apparent to those skilled in the art that AND gate 38 acts as a first blocking means to allow incoming data to be passed only when data exist in a datum position of the new line of data received and there was no data in the corresponding datum positions of the previously passed line of data. AND gate 38 in combination with FLIP-FLOP 46 acts as the first blocking means and the first passing means. AND gate 38 also acts as the receiving means. Output 62 of shift register 58 is connected to input 74 of AND gate 76. The other input 78 of AND gate 76 is connected to the print data source 2. Output 80 of AND gate 76 is connected to input 82 of shift register 84. Clocking means 14 is connected to clock input 86 of shift register 84. AND gate 76 acts as a second comparing means to compare the data being clocked out of shift register 58 to the next line of data received from print data source 2. AND gate 76 will produce the digital HIGH out of output 80 whenever data is detected in corresponding positions for the next line of data received and the line of data stored in shift register 58. Shift register 84 acts as a second storing means to store the signals produced by AND gate 76. Output 88 of shift register 84 is connected to the input 90 of INVERTER 92. The output 94 of INVERTER 92 is connected to the input 96 of OR gate 98. The output 100 of OR gate 98 is connected to input 102 of AND gate 54.
Word enable means 26 is connected to the input 104 of FLIP-FLOP 106. The output 108 of FLIP-FLOP 106 is connected to the input 110 of FLIP-FLOP 112. The output 114 of FLIP-FLOP 112 is connected to input 116 of EXCLUSIVE-OR gate 118.
The circuit in FIG. 2 is not limited to construction with discrete or individual components. This protection circuit can be formed into a hybrid integrated circuit which may in turn lead to a reduction in the number of components.
An individual stylus can use one watt of power to generate a sufficient amount of Joule heat to make a mark on thermal sensitive paper. If there are 512 stylii in an array and a line of incoming data has data in all 512 positions, the stylii would use 512 watts of power. If every successive line also contains data in all positions, this invention would yield an effective reduced power output of 75%.
FIG. 4 shows a print out pattern generated by the present invention for a thermal array containing 16 stylii. An "x" represents data received within a line of data and the "." represents the mark that would be made on the thermal sensitive paper by the stylii using the present invention. FIG. 4 is only a diagrammatic representation of what the typical print out would look like in actual practice of this invention. A typical thermal linear array may contain 512 stylii with a spacing of 100 stylii per inch. New lines of data can typically be received at a rate of 200 lines per second. An individual energized stylus will make a mark on a thermal sensitive paper approximately 0.25 mm in diameter, assuming a stylus of approximately the same size. A maximum paper speed in a thermal recording device in the orthogonal direction from the linear array can typically be 50 mm/sec. FIG. 6 shows a dot pattern produced by one stylus pulsed at a rate of 200 HZ with the paper moving at 50 mm/sec. It can be seen that there is an overlapping of data for successive positions. At even moderate paper speed rates, there can be an overlapping of data by as much as eightfold or more, i.e., there can be as many as eight or more pieces of data printed at least partially on top of each other. Thus, it will be apparent to those skilled in the art that there will be no loss of resolution and no appreciable effect in the print out by use of the present invention. But, it will also be apparent that there will be an effective reduction in the heat produced by the thermal array by as much as 75%.
FIG. 5 illustrates another embodiment of this invention. The embodiment illustrated in FIG. 2 is more particularly useful for displaying graphical data. Since character generation requires a higher degree of resolution, a modification has been made to the FIG. 2 embodiment. Referring now to FIG. 5, the portion of the circuit designated B is essentially the same circuit as shown and described with reference to FIG. 2. Print data A generated by an appropriate source 2A is graphic data, i.e., sine waves, square waves, etc. Print data B generated by an appropriate source 2B is character data. The portion of the circuit designated A' operates identically as described above for the portion of the circuit designated A. Output 132 of AND gate 54 is connected to input 138 of OR gate 136. Print data B from an appropriate source 2B is connected to input 134 of OR gate 136. Output 140 of OR gate 136 is connected to the input of the circuit A'. The output of circuit A' is connected to current drive circuit 10 which is connected to thermal array 12. Clock 14 is also connected to circuit A' but because of inherent timing delays in digital circuitry, may be required to pass through a delay means or skewing means, not shown, prior to the connection with circuit A'. The result of this modification is to allow graphic data to be printed out in the manner described above and to allow character data to be printed out for all datum positions that were not printed in the prior line of data. This gives the needed higher resolution for character data. The effective power reductions are 75% for graphic data and 50% for character data printed. For a more detailed explanation of the operation of the circuit portion designated A' used in character generation, see co-pending application Serial No. 72,542 filed by the same Applicants concurrently herewith, and assigned to the same assignee, which is incorporated herein by reference.
The use of the protection method or the protection circuit is not limited to linear thermal array devices but can be used in any display device that receives successive lines of data wherein the lines of data comprise a plurality of individual datum separated into a number of datum positions.
This invention has been described with reference to preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding of this specification. The intention is to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalent thereof.
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A thermal array protection apparatus is disclosed primarily for use in linear thermal array imaging devices. Data to be printed within a given line of data are compared to data printed within the previous lines of data. Whether data will or will not be printed in the given line of data is a function of the previous data printed. Since the apparatus prevents data from being printed for the same position in successive lines of data, the temperature of the individual thermal imaging stylii will be kept within acceptable limits.
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[0001] This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/DE01/02316 which has an International filing date of Jun. 21, 2001, which designated the United States of America and which claims priority on German Patent Application number DE 100 35 593.5 filed Jul. 21, 2000, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention generally relates to a method or process for decreasing the oxygen content of a copper melt. Preferably, it relates to one whereby at least one flushing plug is arranged in the lower region of the copper melt, and at least one scavenging gas emerges from the flushing plug and ascends into the copper melt.
[0003] The invention also generally relates to a device for decreasing the oxygen content of a copper melt. Preferably, it relates to one whereby the device is essentially constructed in the form of a closed treatment vessel or a closed treatment furnace in which the copper melt can be thermostatically regulated and/or thoroughly mixed by use of an electric current.
BACKGROUND OF THE INVENTION
[0004] Many processes are already known for manufacturing copper and its alloys with very low concentrations of impurities, e.g. less than 50 ppm, and/or with very low oxygen contents, e.g. less than 5 ppm. Similar processes are also used in industry for other metals (e.g. in the case of aluminum and iron).
[0005] The objective of the various technologies in accordance with the prior art usually involves the following:
[0006] the removal of reaction products, and/or impurities, and/or materials comprising slag, and/or the individual/miscellaneous elements that are present in the liquid metal.
[0007] The following are known in this regard in order to achieve the desired refining effects: the use of e.g. filters, the provision of dwell times for settling processes, treatment via additions that react with the impurities, the use of physical separating processes such as e.g. scavenging, the application of a vacuum, etc. in one or more steps in combination with the above technologies, or in the form of the pertinent individual application of these technologies.
[0008] These processes have become known and have found their widest application in the treatment of aluminum and steel along with their alloys, whereas they are used only in part in the copper industry.
[0009] Poling with tree trunks and reducing gases have generally been used from time immemorial for removing the oxygen content of copper during its manufacture. The addition of reducing elements, such as e.g. phosphorus and lithium or boron in the form of e.g. starting alloys, is also known. Use is also made of filters, slag sumps, vacuum chambers/vacuum furnaces and/or settling times in order to purify the metal.
[0010] In the case of copper, all the processes that are listed above are applied and exploited in a widespread manner in order to decrease its very high concentrations of impurities and/or oxygen (e.g. in excess of 200-2000 ppm). Likewise, it is known that deoxidizing agents, such as e.g. phosphorus, can also be used simultaneously as an alloying element for achieving particular material properties.
[0011] In order to manufacture very pure copper materials, use is made almost generally of electrolytically refined copper (cathodes) as the basic material whose level of impurities in the case of stock market registered versions lies below 100 ppm as a result of the preceding steps in the refining procedure (thermal and chemical).
[0012] In the case of the additional thermal processing steps via melting and casting that then always follow on, the concentration of impurities and/or the concentration of oxygen is decreased further as a result of additional process steps and, in part, via the technologies that are listed above, or, as the case may be, the contamination level, which is caused by melting and casting or which is still present, is eliminated.
[0013] Thus, for example, electrical melting down of copper cathodes is used in the form of a discontinuous or continuous standard process for decreasing the oxygen content to below 5 to 15 ppm, whereby, in some processes, the cathodes are additionally heated to 950° C. beforehand via gas burners in order to increase melting efficiency or to remove adhering/included impurities.
[0014] Melting down then takes place in an electric furnace, which is provided with wood charcoal and/or a reducing protective gas, which is largely free from hydrogen, or, preferably, in induction furnaces. Transfer of the liquid copper then takes place via a channel, which, if necessary, is electrically heated and which is also flooded with a reducing/protective gas, and thence into a holding furnace/buffer furnace/settling furnace that is also usually constructed in the form of an induction furnace, and that is again covered with wood charcoal, and/or that it is flooded with a reducing/protective gas. After leaving this furnace, the melt is transferred via a channel, which is also electrically heated and which is flooded with a reducing/protective gas, and thence into an electrically heated tundish that is also covered with wood charcoal, and/or that is flooded with a reducing/protective gas. On its way from the tundish, the liquid metal arrives, usually via a ceramic valve, which is installed in the bottom, in the ingot mold that is, in part, also covered with a reducing/protective gas and/or with e.g. carbon black, whereby the metal solidifies continuously in the ingot mold and is drawn off continuously or discontinuously.
[0015] This standard process that has been described is essentially based on a reducing atmosphere in the furnace and the channels and, in particular, on the large exchange surface between the metal and the reducing/protective gas inside the transfer system in the channels, and also on the long dwell time inside the furnace.
[0016] Processes are also known within, and in addition to, this standard process that, in part, conduct the above process steps without, or only in part with, a reducing/protective gas. Processes are also known that merely seek to achieve low oxygen contents via long dwell times of the liquid metal in an induction furnace under a covering of wood charcoal.
[0017] Moreover, processes are known that additionally undertake the treatment of the liquid metal via a vacuum and/or, additionally, the above standard process or, as the case may be, their modifications.
[0018] It is already known from DE-OS 36 40 753 that a mixture comprising a gaseous hydrocarbon and an inert gas can be blown into a copper melt in order to remove oxygen from the copper melt. This blowing in procedure can take place by using a porous clay brick, or by using a special nozzle.
[0019] An additional process and a device are known from DE-OS 20 19 538 for de-gassing and purifying metal melts. In particular, a procedure is described for decreasing the proportion of oxygen in a copper melt when using porous flushing plugs from which an inert gas emerges that ascends into the copper melt. Reducing or oxidizing gases can be added to the inert gas.
[0020] The devices and processes in accordance with the prior art are not suitable to an adequate extent for decreasing the oxygen content of the metal melt to a proportion of less than 5 ppm in a reproducible manner and at an adequate production speed together with appropriate costs for carrying out the process.
SUMMARY OF THE INVENTION
[0021] A problem for an embodiment of the present invention is therefore to indicate a process such that, in the case of large scale industrial use, a prescribed oxygen content can be achieved in a reproducible manner and at appropriate and low costs relative to the prior art as sketched above.
[0022] In accordance with an embodiment of the invention, this problem may be solved by way of a feature that the copper is initially melted in a gas fired shaft furnace, and then it is led to a treatment furnace via a channel that is also gas fired.
[0023] A device in accordance with DE 2 517 957 C2 can be used as the shaft furnace.
[0024] In this case, the scavenging gas emerges both in the region of the channel and/or in the region of the treatment furnace as a result of flowing out of the flushing (porous) plugs from below, and thence through the copper melt, whereby the scavenging gas flows out from at least one of the flushing plugs with a composition corresponding to 30% to 70% reducing gas and 70% to 30% inert gas. The shaft furnace is configured in such a way that copper with little oxygen and hydrogen and low concentrations of gas is continuously melted and transferred to the channel.
[0025] An additional problem for an embodiment of the present invention is to construct a device of the type that was designated in the introduction such that a decrease in the oxygen content of the copper melt can be implemented in a continuous process and at an appropriate production speed.
[0026] This problem may be solved by way of the feature that flushing plugs are arranged in the region of the bottom and the sides as well as in the outlet region of the treatment furnace in such a way that a vertical flow of ascending scavenging gas is formed within the copper melt, whereby, in addition to the treatment furnace, a completely closed system is formed with controlled conditions for the metal and gases.
[0027] Basically, the process and the device are suitable for being operated completely continuously. Casting of the copper melt can also be carried out discontinuously, depending on the treatment furnace that is used. In particular, thought has been given to melting down the starting material in a shaft furnace that is gas fired and that is favorable in regard to costs.
[0028] As a result of the process in accordance with an embodiment of the invention and the device in accordance with an embodiment of the invention, it is possible to manufacture copper continuously with an oxygen content of less than 5 ppm and with a density that is greater than 8.9. In the event of carrying out the process, both the investment costs for the manufacture of the production plant and the operating costs in DM [German marks]/metric ton are decreased relative to the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Examples of embodiments of the invention are illustrated schematically in the drawings. The following aspects are shown.
[0030] [0030]FIG. 1 shows a cross section through a treatment furnace, and
[0031] [0031]FIG. 2 shows a block circuit diagram in order to illustrate the flow of materials.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] It can be seen from the schematic cross section in FIG. 1 that the process technical treatment of the copper melt takes place inside a treatment furnace ( 1 ). The treatment furnace ( 1 ) is provided with an inlet portion ( 2 ) and an outlet portion ( 3 ). The copper melt is preferably transferred to the inlet portion ( 2 ) from above via a supply port ( 4 ).
[0033] A level for the height of the melt is provided in such a way inside the inlet portion ( 2 ) that a free zone ( 6 ) remains in the perpendicular direction above the filling level ( 5 ) between the melt and the inlet lid ( 7 ). The melt is provided with a cover layer ( 8 ) inside the inlet portion ( 2 ), whereby this cover layer can be formed from e.g. carbon black or wood charcoal. The supply port ( 4 ) extends into the melt in the perpendicular direction so that the supply of melt takes place below the covering layer ( 8 ).
[0034] In the case of the form of embodiment that is illustrated, one or more inlet [porous] flushing plugs ( 10 ) are provided from which the scavenging gas mixture ascends in order to decrease the oxygen content of the melt.
[0035] The inlet portion ( 2 ) is connected to a connecting channel ( 11 ) at the central portion ( 12 ) of the treatment furnace ( 1 ). The connecting channel ( 11 ) extends below the filling level of the melt in the treatment furnace ( 1 ). In particular, thought has been given to arranging the connecting channel ( 11 ) directly above the inlet bottom ( 9 ), and localizing the upper boundary of the connecting channel ( 11 ) at a certain distance from the inlet bottom ( 9 ) such that the inlet channel ( 11 ) is restricted at the top, in a perpendicular direction, to approximately half the filling height of the melt inside the inlet portion ( 2 ).
[0036] A crucible-like depression or tunnel-like depression ( 13 ) is provided in the region of the central portion ( 12 ), whereby the melt flows into this depression. In accordance with the form of embodiment in FIG. 1, thought has been given, in particular, to arranging an inlet bottom ( 15 ) at a certain height in the region of an inlet ( 14 ) of the central portion ( 12 ), whereby this height corresponds to approximately the height, or to the lower level, of the inlet bottom ( 9 ) of the inlet portion ( 2 ). One or more [porous] flushing plugs can be positioned in the region of the inlet bottom ( 15 ) or above the inlet bottom ( 15 ).
[0037] The melt inside the central portion ( 12 ) can also be provided with a cover layer ( 8 ). A gas collection zone ( 17 ) is arranged above the cover layer ( 8 ), whereby this zone is restricted in the upward perpendicular direction by a furnace lid ( 18 ). The furnace lid ( 18 ) has a gas outlet ( 19 ).
[0038] One or more [porous] flushing plugs ( 21 ) are arranged in the region of the bottom ( 20 ) of the central portion ( 12 ). The [porous] flushing plug(s) ( 21 ) is/are preferably placed in such a way that the ascending gas bubbles produce a flow of the melt inside the depression ( 13 ) such that the flow direction in the central region points upward in a perpendicular direction, and a flow direction in the perpendicular direction downward is achieved in the edge regions. These flow directions are sufficiently intensely redirected, e.g. by means of electric fields and/or inductors, that the exchange reactions between the [porous] flushing plug and the melt are intensified/prolonged. As a result of this, one ensures that, in the region of the central portion ( 12 ), a melt, which is flowing in, is initially guided in the direction of the bottom ( 20 ) and that, as a result of this, adequate contact is ensured with the scavenging gas that is emerging from the [porous] flushing plug(s) ( 21 ). If required, the flow that is formed can also be assisted by an electrical heating system that has been provided.
[0039] The central portion ( 12 ) is connected to the outlet portion ( 3 ) via an outlet channel ( 22 ). The outlet channel ( 22 ) has a height localization arrangement that is similar to the connecting channel ( 11 ). An upper height restriction of the outlet channel ( 22 ) is provided at approximately half the filling height of the melt inside the outlet portion ( 3 ). One or more [porous] flushing plug(s) can be arranged in the region of the bottom ( 23 ) of the outlet channel ( 22 ).
[0040] An outlet bottom ( 25 ) is provided in the region of a transition from the central portion ( 12 ) to the outlet channel ( 22 ), whereby this outlet bottom extends to approximately the same height as the channel bottom ( 23 ) and the inlet bottom ( 15 ). One or more [porous] flushing plug(s) ( 26 ) can be placed in the region of the outlet bottom ( 25 ) or above the outlet bottom ( 25 ).
[0041] The melt can also be provided with a cover layer ( 8 ) inside the outlet portion ( 3 ), and a free zone ( 28 ) is provided above the cover layer ( 8 ) between the outlet lid ( 27 ) and the filling level. A outlet opening ( 30 ) for running off the melt is arranged in the region of the outlet bottom ( 29 ).
[0042] In the highly schematic illustration in FIG. 2, the aspect is illustrated that the starting material ( 31 ) that is to be melted is initially supplied to a melting furnace ( 32 ), and then it is transported via a channel ( 33 ) in the region of the treatment furnace ( 1 ). Impacting with scavenging gas can take place in the region of the channel ( 33 ), and in the region of the inlet portion ( 2 ), and in that of the outlet portion ( 3 ), and in that of the central portion ( 12 ). The respective supply lines ( 35 ) for the scavenging gas have been drawn in.
[0043] Melting down via gas in the shaft furnace, whose shaft acts like a heat exchanger, is significantly more efficient and thus more economical in terms of energy than melting down by use of an electric current in the induction furnaces of standard processes.
[0044] The liquid metal, which has been melted in this way and which has been pre-adjusted (in terms, inter alia, of oxygen, total gas content, and impurities) arrives continuously in the gas fired channel ( 33 ) on its way from the sampling hole, whereby this channel is controlled and equipped in a similar manner to that in the cathode shaft furnace.
[0045] The copper arrives in the treatment furnace ( 1 ) on its way from the gas fired and/or electrically heated and covered and/or closed channel ( 33 ), whereby this treatment furnace can simultaneously be a casting furnace.
[0046] In addition to the slag sump, further sumps can be arranged within the length of the channel, whereby these additional sumps are heated by inductors, and whereby [porous] flushing plugs are arranged therein in such a way in the bottom and/or from above that intimate mixing of the liquid metal and the scavenging gases takes place in these sumps. These sumps are connected to the channel ( 33 ) either in a direct serial manner or via siphon-type skimmers.
[0047] The inductors that are designated above can be channel inductors and also crucible inductors. Depending on whether one or several treatment/casting furnaces are being used, the channel ( 33 ) can be arranged such that it is either fixed in position or movable.
[0048] As in the case of melting down, transfer via gas heating is significantly more efficient and thus more economical in terms of energy than transfer in the case of the fully electrically heated channels ( 33 ) of the standard process.
[0049] The treatment furnace ( 1 ) is preferably a closed, fire resistant, masonry lined vessel. This can be arranged in such a way that it is either fixed in position or movable and, moreover, it can be present either in merely single form or in multiple form depending on the casting technology and/or the performance design.
[0050] On its way from the channel ( 33 ), the pre-treated liquid copper, which comes into the treatment furnace ( 1 ), is admitted—e.g. via a bottom drain under the bath or in the flat supply conduit—to the inlet region ( 2 ) of the treatment furnace, whereby this inlet region is covered with reducing agents, e.g. wood charcoal, and it is sealed off from the atmosphere via lids.
[0051] The bottom ( 9 ), and/or the sides, and/or the lids ( 7 ) of the inlet portion ( 2 ) are equipped with flushing nozzles in such a way that intimate mixing together is ensured between the copper, which is flowing in, and the scavenging gas. Depending on its holding capacity, the inlet portion ( 2 ) can also be provided with inductors as in the case of the channel ( 33 ).
[0052] On its way from the inlet portion ( 2 ), the liquid copper, which has been additionally treated in this way, arrives at the central portion ( 12 ) of the treatment furnace ( 1 ) either directly or via a siphon-type skimmer. This portion of the furnace is also sealed off from the atmosphere via a lid ( 18 ), and the metal strip therein is covered with reducing agents, e.g. carbon black.
[0053] The bottom ( 20 ), and/or the sides, and/or the entrance and exit regions of the central portion ( 12 ) are equipped with flushing nozzles in such a way that intimate mixing together is ensured between the copper, which is flowing in, and the scavenging gas.
[0054] In addition, the bottom ( 20 ) is provided with one or more inductors and/or an electromagnetic stirrer so that the melt is moved additionally and, as a result of this, intimate mixing together takes place between the scavenging gases and the copper that is flowing in and out in the case of e.g. continuous operation; the wood charcoal cover and, if required, the melt in the treatment furnace ( 1 ) are held at the required casting temperature or, as the case may be they are brought to this casting temperature.
[0055] On its way from the central portion ( 12 ), the melt arrives at the outlet portion ( 3 ) either directly or via a siphon-type skimmer, whereby this outlet portion is also covered with reducing agents, e.g. wood charcoal, and is sealed off from the atmosphere with lids ( 27 ).
[0056] Depending on the construction, [porous] flushing plugs and inductors can also be installed in the outlet section ( 3 ) in a similar manner to the inlet portion ( 2 ). The melt then arrives in the ingot mold/molds under the bath via a ceramic valve and a ceramic pipe, including a nozzle, under the bath.
[0057] Depending on the casting process, the ingot mold can also be directly flange connected to the outlet portion ( 3 ) under the bath, so that the above mentioned ceramic valve is then eliminated. If the ingot mold is flange connected above the bath, then an appropriate mechanical or electromagnetic pump can be installed in the form of a closed construction, e.g. between the outlet portion ( 3 ) and the ingot mold, or, in the case where the ingot mold is closed, the melt can be drawn into the ingot mold in the form of its solidified billet in accordance with a known process.
[0058] The non flange connected ingot mold and the liquid metal in the upper part of the ingot mold are sealed off from the atmosphere by covering with e.g. a protective gas, and/or carbon black, and/or mixtures of carbon black and wood charcoal.
[0059] Ingot molds that are flange connected or non flange connected are also sealed off from the atmosphere via a protective gas at their end from which metal emerges. The metal is now solidified but it is still hot.
[0060] The protective gas that is used in the channel ( 33 ) and in the treatment furnace ( 1 ) and for the ingot mold essentially consists of an inert gas, such as e.g. argon, nitrogen, and CO/CO 2 mixtures, whereby proportions of inert gas from 100% to 70% in the mixture have proven to be effective depending on the blowing in location, and proportions of CO/CO 2 from 0% to 30% in the mixture have proven to be effective depending on the blowing in location in the case of usage in accordance with the process, which has been described, and for the purpose in accordance with an embodiment of the invention.
[0061] In general, it is expedient to provide a proportion of reducing gas in the range from 40% to 60% of the total gas volume that comprises the reducing gas and the inert gas. The proportion of reducing gas typically amounts to approximately 50%. All the above designated proportions are proportions by volume.
[0062] The proportion of reducing gas in the atmosphere of the furnace ought to lie in the range from 10% to 40%. Typically, this proportion amounts to approximately 20%. The proportion of oxidizing gas components in the atmosphere of the furnace amounts to approximately 0% to 10%. A proportion of 5% is typically present.
[0063] The [porous] flushing plugs, their internal configuration, and their arrangement in the fire resistant masonry lining or in the lids and thus the bath height or blowing-in depth, which is located above them, and their positional distribution and their number in the channel ( 33 ) and in the treatment furnace ( 1 ) are governed by the pertinent parameters that are in place or, as the case may be, the parameters that are to be set up.
[0064] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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The process and the device serve for decreasing the oxygen content of a copper melt. One or more [porous] flushing plugs, from which a scavenging gas emerges, are arranged in the perpendicular direction in the lower region of the copper melt. The scavenging gas ascends into the copper melt, and the copper melt itself is electrically stirred. The copper is initially melted in a shaft furnace, and then it is led to a treatment furnace via a transportation channel. As a result of flowing out of the [porous] flushing plugs, the scavenging gas ascends into the copper melt both in the region of the transportation channel and also in the region of the treatment furnace. The scavenging gas flows out of at least one of the [porous] flushing plugs with a composition corresponding to 30% to 70% reducing gas and 70% to 30% inert gas.
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BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates generally to antennas. More particularly, the present invention is directed to a novel and improved variable length whip and helix antenna system for use in a portable communication device.
II. Description of the Related Art
Portable communication devices, such as portable radiotelephones, typically employ a simple dipole whip antenna as the main antenna. This antenna is usually retractable to make the unit more compact when a call is not in progress. However, when the whip antenna is retracted within the portable radiotelephone housing, the efficiency of the antenna is substantially reduced due to the presence of conductive objects in the antenna pattern.
Several prior art antenna systems attempt to compensate for these object-induced nulls in the whip antenna pattern. For example, some prior art portable radiotelephones utilize a compact helical antenna as an auxiliary antenna, with the main whip antenna extending through the center of the helix. In these prior art portable radiotelephones, the helical antenna remains exposed while the main antenna is retracted within the radiotelephone housing. As such, the helical antenna is able to receive and transmit radio frequency (RF) signals even though the main antenna is retracted.
However, since the main whip antenna extends through the center of the helical antenna, there may be RF coupling between the helical antenna and the whip antenna when the helical antenna is in use, i.e. when the whip antenna is retracted. This coupling results in an undesirable loss of efficiency of the helical antenna. Some prior art antenna systems attempt to avoid this undesirable loss of efficiency due to coupling by fabricating a whip antenna in which a substantial length of the top portion of the whip antenna is constructed of a non-conductive material, such as plastic.
Such a prior art antenna system 100 is illustrated in FIGS. 1A and 1B. In FIG. 1A, prior art antenna system 100 is seen to comprise a whip antenna 102 and a helical antenna 104. Whip antenna 102 comprises a conductive portion 108 and a non-conductive portion 110. Helical antenna 104 is typically encased in a dielectric housing 106 which is external to portable radiotelephone housing 150. In FIG. 1A, whip antenna 102 is fully extended, exposing conductive portion 108. In this position, helical antenna 104 surrounds the bottom of conductive portion 108.
In FIG. 1B, whip antenna 102 is fully retracted, and helical antenna 104 receives and transmits RF signals. In this position, helical antenna 104 surrounds the non-conductive portion 110 of whip antenna 102. Since the non-conductive portion 110 does not couple signal energy from helical antenna 104, the undesirable loss in efficiency by parasitic coupling of whip antenna 102 described above is avoided.
However, a problem with the prior art solution described above is that when whip antenna 102 is in the extended position as shown in FIG. 1A, helical antenna 104 has an unintended effect on the antenna pattern of whip antenna 102. Some of the energy intended to be radiated through whip antenna 102 is coupled to helical antenna 104. In many applications, this parasitic coupling by the helical antenna 104 is undesirable and inefficient in much the same way as the parasitic coupling by the whip antenna 102 as described above.
Another problem with the prior art solution as shown in FIGS. 1A and 1B is that the length of whip antenna 102 must be increased to incorporate non-conductive portion 110. This results in an overall antenna length that is greater than is necessary for whip antenna 102 to perform efficiently. When whip antenna 102 is extended, the non-conductive portion 110 serves no functional purpose, increasing the physical antenna length without increasing the antenna electrical length. This extra length adds size, cost and weight to the portable radiotelephone 150.
What is needed is a combination whip/helix antenna system which operates efficiently whether the whip antenna is extended or retracted, and in which the length of the whip antenna is independent of coupling considerations with the helical antenna.
SUMMARY OF THE INVENTION
The present invention is a novel and improved antenna system for a communication device. In the preferred embodiment, a whip antenna is surrounded by a helical antenna. The preferred embodiment of the antenna system further comprises a mechanical switch which couples the helical antenna to the signal source when the whip antenna is in a retracted position. The whip antenna is comprised of an upper conductive portion, a lower conductive portion, and an intermediate dielectric portion connected between the upper and lower conductive portions and isolating the upper and lower conductive portions from each other. A conductive sleeve member also surrounds the whip antenna and is slidably mounted thereon.
In a first embodiment, the helical antenna and the conductive sleeve member are two separate elements, with the helical antenna being fixedly mounted to the housing of the communication device. In this first embodiment, when the whip antenna is extended, the conductive sleeve member slides over the dielectric portion, coupling the upper and lower conductive portions together. As the whip antenna is retracted, the helical antenna pushes the conductive sleeve member to the top end of the whip antenna, isolating the whip antenna from the helical antenna. Furthermore, when the whip antenna is retracted, the mechanical switch couples the helical antenna to the signal source.
In a second embodiment, the helical antenna is an integral part of the conductive sleeve member. In this second embodiment, when the whip antenna is extended, the conductive sleeve member containing the helical antenna slides over the dielectric portion, coupling the upper and lower conductive portions together through the helical antenna element. The resulting antenna structure is a single radiating element having a lower whip-like conductive portion, an intermediate helical conductive portion, and an upper whip-like conductive portion. As the whip antenna is retracted, the housing of the communication device pushes the conductive sleeve member containing the helical antenna to the top end of the whip antenna, thereby isolating the whip antenna from the helical antenna. Furthermore, when the whip antenna is retracted, the mechanical switch couples the conductive sleeve member containing the helical antenna to the signal source.
In both of the above embodiments, since the conductive sleeve member couples the upper and lower conductive portions together when the whip antenna is extended, the physical length of the whip antenna is dictated only by the desired electrical length, and not by adverse RF coupling considerations. Furthermore, when the whip antenna is retracted, it does not adversely affect the antenna gain pattern of the helical antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:
FIG. 1A is an illustration of a prior art antenna system in which the whip antenna is extended;
FIG. 1B is an illustration of the antenna system of FIG. 1A in which the whip antenna is retracted;
FIG. 2A is an illustration of a first embodiment of the antenna system of the present invention with the whip antenna extended and the sleeve member in cut-away view;
FIG. 2B is an illustration of the antenna system of FIG. 2A with the whip antenna retracted and the sleeve member in cut-away view;
FIG. 3A is an illustration of an exemplary portable radiotelephone, shown in partially cut-away view, employing the first embodiment of the antenna system of the present invention with the whip antenna extended;
FIG. 3B is an illustration of an exemplary portable radiotelephone of FIG. 3A with the whip antenna retracted;
FIG. 4A is an illustration of a second embodiment of the antenna system of the present invention with the whip antenna extended and the sleeve member in cut-away view; and
FIG. 4B is an illustration of the antenna system of FIG. 4A with the whip antenna retracted and the sleeve member in cut-away view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the antenna system 200 of the present invention as shown in FIGS. 2A and 2B comprises a whip antenna 202 inserted longitudinally through the center of helical antenna 204. Helical antenna 204 is preferably encased in a dielectric casing 206 such as plastic, and is mounted externally on portable radiotelephone housing 250 by means known in the art; for example, by a threaded insert (not shown). Whip antenna 202 may be extended as shown in FIG. 2A, or retracted within portable radiotelephone housing 250 as shown in FIG. 2B. In this first embodiment, regardless of whether whip antenna 202 is extended or retracted, helical antenna 204 remains mounted externally on housing 250.
When whip antenna 202 is extended as shown in FIG. 2A, the helical antenna 204 is preferably not used, although it may be used to intentionally augment or alter the antenna gain pattern of whip antenna 202. In order to switch out helical antenna 204 when whip antenna 202 is extended, a variety of electrical or mechanical switches may be used. For example, in FIGS. 2A and 2B, a feed point 220 of helical antenna 204 extends downwardly from the coils of helical antenna 204. As can be seen from FIG. 2B, when whip antenna 202 is in a retracted position, feed point 220 is contacted by a spring arm 222 which provides signals to and from the radiotelephone's transceiver (not shown). Spring arm 222 is held securely against feed point 220 by a lateral spring force. However, when whip antenna 202 is in an extended position as shown in FIG. 2A, a widened portion 224 at the bottom of whip antenna 202 engages spring arm 222, pushing spring arm laterally away from feed point 220 and electrically de-coupling spring arm 222 from helical antenna feed point 220. By switching out helical antenna 204 when whip antenna 202 is extended, one may avoid undesirable alterations or inefficiencies in the antenna gain pattern of whip antenna 202 when it is extended.
In another aspect of the first embodiment of the present invention, whip antenna 202 comprises an upper conductive portion 209, a lower conductive portion 208, and an intermediate dielectric portion 210. A sliding sleeve member 211 surrounds whip antenna 202 and is slidably mounted thereon. In this first embodiment, sleeve member 211 is made of a conductive material, such as copper, steel or the like, and optionally may be outwardly encased in a protective dielectric material such as plastic (not shown). Also, although helical antenna 204 is illustrated in FIG. 2A and 2B as a proper helix, it may also be of other construction as is known in the art; for example a solid cylinder, a braided mesh, or a loop antenna. Likewise, whip antenna 202 may be of various constructions, such as telescopic or fixed length. Both upper and lower conductive portions 209, 208 are constructed from metallic materials as are known in the art. Also, intermediate dielectric portion 210 is preferably constructed of a strong plastic, but may alternately be made of any non-conductive composite dielectric material as are known in the art.
When whip antenna 202 is extended from the portable radiotelephone housing 250 as shown in FIG. 2A, sleeve member 211 couples upper conductive portion 209 to lower conductive portion 208, thus bypassing intermediate dielectric portion 210 and providing electrical continuity throughout the length of whip antenna 202. In this extended position, whip antenna 202 conducts RF signals throughout its length. Current oscillates in whip antenna 202 through conductive portion 208, sleeve member 211, and upper conductive portion 209, enabling whip antenna 202 to transmit and receive RF signals using its entire physical length.
As was previously mentioned, when whip antenna 202 is extended as shown in FIG. 2A, helical antenna 204 may be switched out by the engagement of widened portion 224 with spring arm 222. In addition to switching out helical antenna 204, spring arm 222 may also be used to couple whip antenna 202 to the radiotelephone's transceiver (not shown) if widened portion 224 is made of a conductive material, or is an integral part of lower conductive portion 208. In such an embodiment, spring arm 222 would conduct RF signals to and from whip antenna 202 through widened portion 224 when whip antenna 202 is in the extended position shown in FIG. 2A, and would conduct RF signals to and from helical antenna 204 through feed point 220 otherwise, for example, when whip antenna 202 is in the retracted position shown in FIG. 2B.
In the first embodiment shown in FIGS. 2A and 2B, sleeve member 211 is a metallic cylinder having an inward turned "lip" or taper at each end for contacting the upper and lower conductive portions 209, 208. Alternatively, sleeve member 211 may be a "clip" arrangement which does not completely surround whip antenna 202. Optionally, an upper lip of sleeve member 211 also engages sleeve stop 212. Sleeve member 211 physically rests against sleeve stop 212 when whip antenna 202 is in the extended position illustrated in FIG. 2A. Sleeve stop 212 may be a "bump" on the upper conductive portion 209 as shown, or it may be a mere widening or flare of upper conductive portion 209. Alternatively, sleeve stop 212 may be an integral part of lower conductive portion 208 as is shown in FIGS. 2A and 2B. Clearly, there are may different ways to physically suspend sleeve member 211 such that it bridges intermediate dielectric portion 210, coupling upper conductive portion 209 to lower conductive portion 208.
When whip antenna 202 is retracted substantially within portable radiotelephone housing 250 as shown in FIG. 2B, sleeve member 211 is pushed to the top of whip antenna 202, de-coupling upper conductive portion 209 from lower conductive portion 208, and allowing intermediate dielectric portion to electrically isolate upper conductive portion 209 from lower conductive portion 208. In this retracted position, helical antenna 204 is isolated from lower conductive portion 208 by the physical distance of intermediate dielectric portion 210. As such, RF signals received and radiated by helical antenna 204 are not coupled to the entire length of whip antenna 202, although there may be some negligible coupling to sleeve member 211 and upper conductive portion 209.
In the first embodiment shown in FIG. 2B, sleeve member 211 has an outer diameter smaller than the inner diameter of helical antenna 204, and thus slides in between upper conductive portion 209 and helical antenna 204 when whip antenna 202 is in the retracted position. The sliding of sleeve member 211 as whip antenna 202 is moved from the extended position of FIG. 2A to the retracted position of FIG. 2B may be arrested by engaging a lower lip on sleeve stop 212. Alternatively it may be arrested by engaging an upper lip on a widened upper end of upper conductive portion 209. Based on the length of sleeve member 211 and the size and location of intermediate dielectric portion 210 along the length of whip antenna 202, one may design many different schemes as are known in the art for limiting the travel of sleeve member 211 along the length of whip antenna 202.
FIGS. 3A and 3B illustrate a partially cut-away view of the first embodiment of the antenna system 200 of the present invention employed by a portable radiotelephone 250 suitable for use with the present invention. When whip antenna 202 is in the extended position of FIG. 3A, spring arm 222 engages widened portion 224, switching out the helical antenna encased in dielectric housing 206. Also, sleeve member 211 (here shown as a metallic cylinder with a lip at a top end) couples upper conductive portion 209 to lower conductive portion 208, providing for full electrical continuity along the length of whip antenna 202. When whip antenna 202 is in the retracted position of FIG. 3B, spring arm 222 connects to the helical antenna encased in dielectric housing 206. Also, sleeve member 211 slides to the top of upper conductive portion 209, thus de-coupling upper conductive portion 209 from lower conductive portion 208. In this position, the upper conductive portion 209 of whip antenna 202, and the helical antenna encased in dielectric housing 206 are isolated from lower conductive portion 208 by intermediate dielectric portion 210.
In this first embodiment of the present invention, spring arm 222 provides for the reduction of parasitic coupling by helical antenna 204 (see FIGS. 2A and 2B) when whip antenna 202 is extended, while sleeve member 211 provides for the reduction of parasitic coupling by whip antenna 202 when whip antenna 202 is retracted. Furthermore, sleeve member 211 allows the full physical length of whip antenna 202 to be used for receiving and radiating RF signals, without adding the additional length required in the prior art antenna system shown in FIGS. 1A and 1B. Thus, the physical length of whip antenna 202 in the present invention is independent of adverse coupling considerations found in the prior art antenna systems. Additionally, sleeve member 211 adds negligible size and weight to the phone, and may be compactly stored within helical antenna 204 when whip antenna 202 is retracted.
A second embodiment of the antenna system 200 of the present invention is illustrated in FIGS. 4A and 4B. This second embodiment is similar to the first embodiment in that sleeve member 211 couples upper conductive portion 209 to lower conductive portion 208 when whip antenna 202 is in the extended position as shown in FIG. 4A. However, in contrast to the first embodiment, helical antenna 204 is not fixedly mounted to the housing of portable radiotelephone 250. In this second embodiment, helical antenna 204 is an integral part of sleeve member 211, and current actually flows through helical antenna 204 when whip antenna 202 is in the extended position. Preferably, in this second embodiment, with the exception of helical antenna 204, sliding sleeve member 211 is a non-conductive dielectric plastic material. Thus, when whip antenna 202 is extended, the resulting radiating element comprises a whip-like lower conductive portion 208, the intermediate helical conductive portion of helical antenna 204 encased in sleeve member 211, and the upper conductive portion 209. When whip antenna 202 is in this extended position, helical antenna 204 behaves like a phasing coil, extending the electrical length of whip antenna 202, while concentrating its radiating pattern along the horizontal plane. Alternatively, sleeve member 211 may still be a conductive material, however this would obviate the need for the helical antenna 204, and the sleeve member 211 would merely act as a cylindrical radiator.
When whip antenna 202 is retracted as shown in FIG. 4B, sleeve member 211 and integral helical antenna 204 are pushed to the top of whip antenna 202, but remain exposed externally to portable radiotelephone housing 250. However, feed point 220 of helical antenna 204 extends internally into portable radiotelephone housing 250 to make electrical contact with spring arm 222. Thus, when whip antenna 202 is retracted, this second embodiment behaves similarly to the first embodiment of FIGS. 2A and 2B with helical antenna 204 acting as the primary radiator, while still isolating lower conductive portion 208 from whip antenna 204 by intermediate dielectric portion 210. Alternatively, feed point 220 may be directly coupled to sleeve member 211 if sleeve member 211 is made from a conductive material. In such a case, the sleeve member 211 would act as a cylindrical radiator.
The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. The various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
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An antenna system for a communication device. A whip antenna is surrounded by a helical antenna. A switch couples the helical antenna to the signal source when the whip antenna is in a retracted position. The whip antenna is comprised of an upper conductive portion, a lower conductive portion, and a dielectric portion which isolates the upper and lower conductive portions from each other. A conductive sleeve member surrounds the whip antenna and is slidably mounted thereon. In a first embodiment, when the whip antenna is extended, the conductive sleeve member slides over the dielectric portion, coupling the upper and lower conductive portions together. As the whip antenna is retracted, the helical antenna pushes the conductive sleeve member to the top end of the whip antenna, isolating the whip antenna from the helical antenna. In a second embodiment, the helical antenna is an integral part of the conductive sleeve member.
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