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DESCRIPTION
1. Technical Field
This invention relates to roving frames and more particularly to a novel and improved mechanism for fixing a thread winding bobbin in driven engagement with a driving spindle.
2. Background Art
In the textile industry threads are manufactured in machines known as roving frames. As a thread is manufactured it is wound on a bobbin. With a typical roving frame a bank of bobbins are concurrently spun at speeds in the order of 1,200-1,400 revolutions per minute as newly formed thread is wound on each. Each bobbin is removably mounted on a drive spindle and each has a coacting flier which functions to distribute the thread evenly on the bobbin as thread is wound on the bobbin.
One type of roving machine which is now widely used, incorporates a bank of vertically extending drive spindles each of which has a driving spur at its top. When the machine is in use, each spindle carries a bobbin, hopefully in driven relationship. The driving spur and bobbin have coacting torque transmitting surfaces. An annular groove is formed in the spur surfaces and an O-ring is mounted in this groove. The O-ring is intended to frictionally engage the coacting surfaces of the bobbin to assist in maintaining the bobbin on the spindle.
Each bobbin has a frusto conical shaped surface near its top which coaxially communicates with a spindle and drive spur receiving bore formed in the bobbin. The driving spur has a plurality of machined slots each of which carries a ball. As the spindle commences to rotate, it is intended that centrifugal force will drive these balls radially outwardly into engagement with the frusto conical surface of the bobbin and provide a bobbin retaining lock.
In practice, the described bobbin retaining mechanism has too often failed to achieve its bobbin retaining function. As a consequence, the bobbin may be thrown from the spindle causing damage to fliers, spindles, bobbins, and other roving frame components. If the bobbin is not being driven properly, it is necessary for the operator to stop the entire machine and in some instances remove the bobbin entirely shutting down the production of one of the thread roving components of the machine. Alternately, if the spindle or bobbin is worn to the point that they will not function properly but only to a point where they still can be caused to function, the operator will laborously make a paper shim which is inserted between the bobbin and spindle for the purpose of providing enough friction between them to hold the bobbin on the spindle in an adequately driven relationship.
It will be apparent that the deficiencies of the described bobbin retaining arrangement are such that it is common for a number of spindles of bank to be non-functioning reducing the productivity of the machine. It is also all to common that the machine must be shut down while the operator makes a "fix" to cause as many spindles as possible to appropriately and properly drive associated bobbins.
DISCLOSURE OF INVENTION
According to the present invention, a novel and improved locking arrangement has been conceived which can be retrofit in place of the previously described bobbin drive spur to effectively lock bobbins in place on their associated spindles. Indeed, this new locking arrangement is so effective that badly worn spindles, which would be well beyond their normal productivity with the prior bobbin drive spurs arrangements, continue to function for their intended and desired thread winding procedures.
The bobbin lock of this invention improves the efficiency and profitability of a roving operation by virtually eliminating damage due to bobbins coming off spindles, insuring virtually all spindles are indeed used for thread winding, significantly reducing downtime due to malfunctioning bobbin locking arrangements and significantly reducing the frequency with which spindles must be replaced.
A lock made in accordance with this invention has a body with a through stepped bore. A lower portion of the bore telescopes over the spindle and the body is pin connected to it. A central reduced diameter bore portion communicates with the lower portion and the two are connected by a radially extending clamping shoulder. A headed cam stem projects through central bore and extends upwardly past the top of the body. The head of the stem coacts with the clamping shoulder.
An overcenter cam is rotatably connected to the stem near its top to act against a cam disc which in turn acts against an elastomeric retainer. A spring is carried in a large upper bore portion urging the retainer upwardly and with it the cam and stem so that the head is maintained in engagement with the clamping shoulder.
When the cam is in a release position a spindle may be telescoped over the lock device and down over the spindle until complemental surfaces on the bobbin and the lock body are in engagement for the transmission of bobbin rotation torque. The cam is then moved to a locked position to distend the retainer into bobbin retaining lock engagement with the frusto conical shaped surface designed for engagement with the radially movable centrifugal balls of the prior art. With the retainer so deformed the bobbin is firmly locked on the spindle and will not accidently be removed.
While the bobbin is firmly locked on the spindle, it is nonetheless facilely removable by manual action. When a bobbin is manually raised against the action of the elastomeric retainer, the retainer is sufficiently deformable to permit the bobbin to be moved axially into engagement with a cam tab. Thereafter the bobbin is moved upwardly against the tab until the cam passes over center and the entire locking arrangement is released. Alternately the cam can easily be moved to its release position when an operator simply rotates it about the pivotal connection of the cam stem.
Thus, the locking device of this invention is a positive action device with finger trip control which will not increase either stopping or startup times compared with the prior art. In addition if a spindle falls unlike the prior art, the bobbin is automatically released from the spindle and no damage results. The device has no screws to be released and no adjustments are necessary. In addition to all of these advantages tests have shown that the device will drive a bobbin with the order of 50-80% of the bobbin drive surfaces being worn away and yet there is no noticeable slippage.
Accordingly, an object of this invention is to provide a novel and improved locking device for assuring driving relationship between a spindle and a bobbin.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary sectional view showing a top portion of a bobbin in cross section, a top portion of a spindle and the locking mechanism of this invention interposed between the spindle and the bobbin.
FIG. 2 is an exploded view showing the lock mechanism in its release position and the relative spatial relationship of a bobbin and spindle as the bobbin is about to be placed on, or is being removed from, the spindle.
FIG. 3 is a cross-sectional view of the lock mechanism of this invention in its locked position; and,
FIG. 4 is a cross-sectional view of the lock mechanism of this invention showing the cam in its release position.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to the drawings, a bobbin lock assembly made in accordance with this invention is shown generally at 10. The lock assembly 10 is mounted on a spindle 12 for rotation with it. A thread winding bobbin 13 telescopes over the assembly 10 and the spindle 12 and is retained in place on the spindle when the lock is in the position shown in FIGS. 1 and 3.
The lock assembly 10 includes a tubular lock body 15. The body 15 has a through bore including a lower spindle receiving portion 16. The body telescopes over a reduced diameter spindle top portion 17 and seats against the spindle shoulder 18, FIG. 1. A pin 20 extends radially through aligned transverse bores in the spindle and the body 12, 15 to fix the two together and maintain the lock assembly 10 fixedly connected to the spindle 12.
The body 15 includes external hexagonal torque transmitting surfaces 22 which engage complemental surfaces 23 formed in the bobbin to provide torque transmission between the spindle and the bobbin when the spindle is rotated. The body has a frusto conical bobbin support surface 24 which engages a complemental bobbin surface 25 to provide vertical support for the bobbin. Radial location of the bobbin on the lock is provided by coacting cylindrical surfaces 26, 28 formed on the body and in bobbin respectively.
A frusto conical outwardly flaring lock surface 29 is formed near the top of the bobbin in coaxial alignment with the cylindrical surface 28 and the bobbin complemental supporting surface 25.
The body 15 has a central bore portion 30 which is axially aligned with and in communication with the spindle receiving bore portion 16. A radially extending annular clamping shoulder 32 interconnects the spindle and central bore portions 16, 30. A cam stem mechanism is provided which includes a stem 34 and head 35. The head 35 abuts the shoulder 32 while the stem 34 extends axially upwardly through the central bore portion 30 and an axially aligned upper spring receiving bore portion 36. An annular radially extending spring engaging shoulder 37 connects the central and the spring bore portions 30, 36.
An overcenter actuator cam 40 is rotatably mounted on the stem 34 by a cam pin 41. Cam 40 includes a central strut section 42 and a pair of spaced and parallel cam lobe sections 43a, 43b. The cam lobe sections 43a, 43b are perpendicular to the strut section 42 projecting from edge portions of it. As can best be seen in FIG. 2 the cam pin 41 extends through both of the cam lobe sections 43a, 43b to secure the cam in its rotational engagement with the cam stem 34.
The cam has a pair of essentially semi-circular camming lobes 44a, 44b. These lobes act against a camming disk 46 which is a substantially flat annulus that is mounted around the cam stem 34. A deformable elastomeric retainer 47 is around the cam stem 34. The retainer is interposed between camming disk 46 and an annular radially extending top surface 48 of body 15.
A retainer release coil spring 50 is disposed in the spring bore portion 36 and interposed between the retainer 46 and the spring shoulder 37. When the cam is in its locked position as shown in FIGS. 1 and 3 the retainer is compressed against the top surface 48 and deformed into bobbin locking engagement as is shown in FIG. 1. When the cam is in this locked position the spring 50 is compressed into an ineffectual position.
The cam 40 includes an actuating tab 52 which may be grasped manually and rotated counterclockwise from the position of FIGS. 1 and 3 to the position of FIG. 4 which is the cam release position. When the cam is in the release position in FIG. 4 the coil spring 50 elevates the now relaxed and substantially undeformed retainer 47 against the disk 46. The disk in turn acts against the cam and thus elevates the cam stem 34 maintaining the head 35 in engagement with the clamping shoulder 32.
Should a spindle have a failure known in the textile industry as a "fall" the bobbin will act against the tab 52 thereby shifting the cam to its release position 54 so that no further damage will result.
While a preferred embodiment of the invention has been disclosed in detail, various modifications or alterations may be made herein without departing from the spirit and scope of the invention set forth in the appended claims.
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A new locking arrangement is disclosed for effectively locking bobbins in place on associated roving machine spindles. The locking arrangement includes a body that is drivingly connected to the spindle and has torque transmitting surfaces coacting with the bobbin. A deformable retainer is moveably coupled to the body. An over center cam is moveably coupled to the body and is coactable with the retainer in retainer compression and a retainer release position. When the cam is in the compression position, the retainer is deformed into a lock producing position securing the body and the bobbin in a torque transmitting relationship with forces which include an axial vector urging the members together. When the cam is in a release position, the bobbin can be removed from the spindle.
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This application claims priority under 35 U.S.C. §§119, 120 and/or 365 to Patent Application No. 20020881 filed in Finland on May 8, 2002 and to International Application No. PCT/FI03/00354 filed on May 7, 2003; the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The invention relates to a percussion device having means for providing a stress pulse in a tool connected to the percussion device.
BACKGROUND OF THE INVENTION
In known percussion devices an impact is produced using a reciprocating percussion piston, whose motion is typically generated hydraulically or pneumatically and in some cases electrically or by means of a combustion engine. A stress pulse is produced in the tool, such as a drill rod, when the percussion piston strikes the impact surface of a shank adapter or tool.
The known percussion devices have a drawback that the reciprocating motion of the percussion piston generates dynamic acceleration forces that make the control of the apparatus difficult. As the percussion piston accelerates in the striking direction, at the same time the body of the percussion device tends to move in the opposite direction so as to alleviate the pressing force of a drill bit or a tool tip with respect to the material to be treated. In order to maintain the pressing force of the drill bit or the tool sufficient against the material to be treated, it is necessary to push the percussion device with sufficient force towards the material. This, in turn, brings about a problem that the extra force must be taken into account both in the supporting structures of the percussion device and elsewhere, as a result of which the size and mass of the apparatus as well as the manufacturing costs will increase. Inertia resulting from the mass of the percussion piston restricts the frequency of the reciprocating motion of the percussion piston, and thus, the impact frequency, which, instead, should be considerably raised from the present level in order to achieve a more efficient result. The result of the current solutions is considerable deterioration of operating efficiency, however, and therefore it is not possible in practice.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a percussion device, advantageously for a rock drilling machine or the like, in which adverse effects of percussion-induced dynamic forces are lower than in the known solutions and by which it will be easier to increase the impact frequency than at present. The percussion device of the invention is characterized in that the means for providing a stress pulse include an energy storing space, which is located in the body of the percussion device and limited by the body of the percussion device and a separate transmission element located movably in the axial direction of the tool with respect to the body of the percussion device, the energy storing space being filled with elastic and reversible compressible energy storing material, means for bringing the energy storing material to stress state by increasing its pressure so that when the energy storing material is in a desired state of stress, the transmission element is in a position with respect to the body of the percussion device, from which position it can move with respect to the body of the percussion device towards the tool, and correspondingly, means for releasing the transmission element abruptly to move towards the tool, whereby the energy stored in the energy storing material is discharged as a stress pulse via the transmission element to the tool that is directly or indirectly in contact therewith.
The basic idea of the invention is that energy storable in an elastic and reversible, compressible material, which is compressed and whose compressibility is relatively low, such as fluid, rubber, elastomer, etc, is used for providing an impact. The energy is transferred to the tool by releasing the compressed material abruptly from the stress state, whereby the material tends to restore its rest volume and by means of the stored stress energy it delivers an impact, i.e. a stress pulse, to the tool.
The invention has an advantage that the impulse-like impact motion provided in this manner does not require a reciprocating percussion piston, and therefore large masses are not moved to and fro in the striking direction, and the dynamic forces remain low as compared with the dynamic forces of heavy reciprocating percussion pistons in the known solutions. Further, the present structure enables a raised impact frequency without considerable deterioration of operating efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention will be described in greater detail in connection with the attached drawings, wherein
FIG. 1 shows schematically an operating principle of a percussion device according to the invention;
FIG. 2 shows schematically an embodiment of the percussion device according to the invention;
FIG. 3 shows schematically a second embodiment of the percussion device according to the invention;
FIG. 4 shows schematically a third embodiment of the percussion device according to the invention;
FIG. 5 shows schematically a fourth embodiment of the percussion device according to the invention;
FIG. 6 shows schematically a fifth embodiment of the percussion device according to the invention;
FIG. 7 shows schematically a sixth embodiment of the percussion device according to the invention; and
FIG. 8 shows a seventh embodiment of the percussion device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows schematically an operating principle of a percussion device according to the invention. In the figure, a broken line indicates a percussion device 1 and its body 2 , at one end of which there is mounted a tool 3 that is movable in its longitudinal direction with respect to the percussion device 1 . Inside the body 2 there is an energy storing space 4 , which is filled with elastic and reversible, compressible energy storing material 4 a. The energy storing space 4 is partly limited by a transmission element 5 between the energy storing material 4 a and the tool 3 , which element can move in the axial direction of the tool 3 with respect to the body 2 . Fluid, which constitutes by way of example the energy storing material 4 a, is compressed with such a force that its volume, i.e. in this case its axial length in the direction of the tool 3 , changes as compared with the length at rest. Correspondingly, the fluid pressure changes, i.e. rises, in proportion to the compression. Naturally, to generate stress in the energy storing material requires energy that is made to affect the energy storing material 4 a in various ways hydraulically, for instance, of which there are practical examples in FIGS. 2 and 3 .
As the energy storing material is stressed, for instance compressed as in the figure, the percussion device 1 is pushed forwards such that the end of the tool 3 is firmly pressed against the transmission element 5 either directly or through a separate transmission piece, such as a shank adapter or the like. By releasing abruptly the stress state of the material a stress wave is produced, which propagates in the direction of arrow A, in a drill rod or another tool and which delivers an impact on reaching the front end of the tool in the material to be treated, in the same way as in the known percussion devices.
The length and the intensity of the propagating stress wave, are in proportion to the volume and stress state of the energy storing material as well as to the physical characteristics of the tool and the energy storing material.
FIG. 2 shows schematically an embodiment of a percussion device according to the invention. In this embodiment a transmission piston serves as a transmission element 5 between the energy storing material 4 a and the tool 3 . Between the transmission piston 5 ′ and the body 2 there is a separate working cylinder 6 , into which pressure medium can be fed so as to generate stress. The pressure fluid is fed from a pressure fluid pump 7 via a channel 9 to the working cylinder 6 controlled by a valve 8 for generating stress. Thus, the pressure of the pressure fluid pushes the transmission piston 5 ′ to the left as indicated in FIG. 2 , whereby the fluid constituting the energy storing material 4 a is compressed in the axial direction of the tool 3 and its pressure rises. As the prestress has reached a desired level, the position of the valve 8 is changed such that the pressure fluid can be discharged from the working cylinder 6 to a pressure fluid container 10 and the fluid pressure in the compressed energy storing material 4 a tends to transfer the transmission piston towards to the tool 3 . Because the percussion device 1 is pushed in the manner known per se by a feeding force F towards the tool 3 , and the tool 3 is pushed through the energy storing material via the transmission piston towards material to be broken, not shown, a stress pulse is generated in the tool 3 and this stress pulse propagates through the tool 3 to the material to be broken and makes the material break. In the embodiment of FIG. 2 , the surface of the transmission piston 5 ′ facing the working cylinder 6 has a larger cross-section than the surface facing the energy storing material 4 a. However, this is in no way restrictive in this embodiment, but the surfaces may be equal in size, have the same proportions as in FIG. 2 or vice versa. Further, FIG. 2 does not propose any particular seals known per se in relation to the transmission piston and the working cylinder or the walls of the energy storing space 4 containing the energy storing material 4 a, because the seals are generally known per se and apparent to a person skilled in the art, and they are not relevant to the actual invention. Any suitable structure known per se can be applied to the sealing solutions.
FIG. 3 shows a second embodiment of the percussion device according to the invention. In this embodiment the stressing of the energy storing material is implemented with a two-part transmission piston. In this embodiment the transmission piston 5 ″ comprises a separate working flange 5 a, which closes at one end the energy storing space 4 containing the fluid that serves as the energy storing material 4 a. Correspondingly, the transmission piston 5 ″ extends outside the energy storing space 4 , at the end opposite to the tool 3 , into a separate working cylinder space 6 , where there is a separate auxiliary piston 5 b associated with the transmission piston 5 ″. In this embodiment the transmission piston is pulled by feeding pressure fluid in the working cylinder 6 by means of the auxiliary piston 5 b, whereby the fluid acting as the energy storing material 4 a is compressed. At the same time, part of the energy is also stored in the transmission piston 5 ″ as tensile stress. Otherwise the operation of this solution corresponds to that of FIG. 2 .
FIG. 4 shows schematically a third embodiment according to the invention. It proposes a structure by which the magnitude of a stress pulse can be raised without the pressure fluid pump 7 having to provide particularly high pressure of the pressure fluid. This embodiment comprises one or more separate pressure intensifier pistons 11 communicating with the working cylinder 6 . In the case shown in FIG. 4 , the intensifier piston is in its rest position. Pressurized fluid can then be fed into the working cylinder 6 in the previously described manner. When the pressure of the pressure fluid is sufficient in the working cylinder 6 , the pressure fluid feed is stopped with a valve 12 , and at the same time the pressure fluid feed is conducted via a channel 13 to the pressure intensifier piston 11 . By feeding the pressure fluid the pressure intensifier piston 11 is pushed towards the cylinder space of the working cylinder 6 , whereby the pressure in the working cylinder 6 further increases and consequently the volume of the fluid acting as the energy storing material 4 a further reduces and the pressure correspondingly rises. After pushing the pressure intensifier piston 11 to a desired point, the pressure fluid flow is released abruptly from the working cylinder 6 and from behind the pressure intensifier piston 11 , whereby a stress pulse is generated in the tool in the previously described manner.
As shown in FIG. 4 , it is possible to push the pressure intensifier piston by means of a separate control valve 12 utilizing the pressure of the pressure fluid pump 7 . In that case when the valve 12 is switched downwards from the position shown in FIG. 4 the pressure fluid channel 9 leading to the working cylinder 6 is closed and the pressure fluid flows to the pressure intensifier piston 11 . Correspondingly, when the valve 8 is switched upwards from the position shown in FIG. 4 and the valve 12 is restored to the position of the figure, the pressure fluid can be discharged both from the working cylinder 6 and from behind the pressure intensifier piston 12 , whereby a stress pulse is generated.
FIG. 5 shows schematically a fourth embodiment of the invention. In this embodiment, the pressure of the pressure fluid in the working cylinder is used for enhancing the stress pulse to be provided in the tool. In this embodiment, at the beginning of a working phase the transmission piston 5 ′ moves against shoulders 13 on the left in the figure, and the pressure fluid from the pump 7 is fed into the working cylinder 6 and pressure fluid will be discharged from the energy storing space 4 into the pressure fluid container 10 . Thereafter the valve 8 is switched downwards in the figure to its midmost position, whereby the channel 9 leading to the working cylinder 6 is closed and a closed pressure fluid space is formed. At the same time, pressure fluid is fed from the pump 7 into the energy storing space 4 , and the pressure fluid therein is compressed to have a smaller volume than originally by the effect of the intruding pressure fluid, and the pressure in the space 4 rises. Because the pressure surface of the transmission piston 5 is larger on the side of the energy storing space 4 than on the side of the working cylinder 6 , the pressure in the working cylinder rises higher than the pressure from the pump 7 in the inverse proportion to the pressure surfaces. After feeding a sufficient amount of pressurized fluid acting as the energy storing material 4 a from the pump 7 into the energy storing space 4 , the valve is switched further downwards to its third position, in which the pressure fluid supply from the pump 7 is blocked and the highly pressurized pressure fluid can flow from the working cylinder 6 into the energy storing space 4 until the pressures are equal. As this is done abruptly, the transmission piston 5 ′ tends to move in the direction of the tool 3 generating thus a stress pulse in the tool 3 in the previously described manner.
FIG. 6 shows a fifth embodiment of the percussion device according to the invention. In this embodiment the energy storing space differs in shape from the previous embodiments. The energy storing space 4 is limited by a separate membrane 4 b, which results in a closed energy storing space 4 . On the other side of the membrane 4 b there is a separate transmission piece 5 ′″ that acts as the transmission element and is in direct or indirect contact with the tool 3 . Further, there is a pressure fluid space 6 ′ on the side of the membrane 4 b facing the tool 3 . When pressure fluid is fed into the pressure fluid space 6 ′, and correspondingly, when pressure is released from the pressure fluid space, a stress pulse is generated in the tool in the previously described manner.
FIG. 7 shows schematically a sixth embodiment of the percussion device according to the invention. This embodiment corresponds to the solution of FIG. 5 in all other respects but the energy storing space is provided with a separate volume adjustment piston 16 , which in this case, by way of example, adjusts the length of the energy storing space having a constant cross-section. The piston position can be changed by adjustment means, such as a mechanical screw, which is schematically illustrated by a screw 17 . When the screw is turned in either direction as indicated by arrow B, the adjustment piston 16 moves in the energy storing space 4 such that the volume of the space 4 reduces or increases depending on the turning direction of the screw 17 . Instead of the screw 17 it is possible to use any other solution known per se for shifting the adjustment piston 16 and thus for adjusting the volume of the energy storing space 4 . The change in the volume can be used for controlling the properties, such as amplitude and length, of the stress pulse.
FIG. 8 shows a seventh embodiment of the percussion device according to the invention. This embodiment corresponds in part to that shown in FIG. 4 . However, in this embodiment the pressure intensifier piston 11 is located on the side of the energy storing space 4 . The operation takes place such that when the valve 8 is in the position shown in FIG. 8 , pressure fluid flows from the pressure fluid pump 7 into the working cylinder 6 pushing the transmission piston 5 ′ towards the energy storing space 4 a. At the same time, the pressure fluid is able to flow from behind the pressure intensifier piston 11 into the pressure fluid container 10 in the manner which enables the transmission piston 5 ′ to push its flange against the shoulders. Thereafter the valve 8 is switched from the position shown in FIG. 8 to the midmost position, i.e. upwards in the figure, whereby the working cylinder 6 will become a closed space and pressure fluid flows from the pump 7 via the channel 13 behind the pressure intensifier piston 11 pushing it towards the energy storing space 4 a, and consequently the pressure in the energy storing space rises as the volume reduces. At the same time the pressure in the working cylinder also rises, because the pressure liquid cannot be discharged therefrom. After the pressure in the energy storing space 4 has reached a sufficiently high level, the valve 8 is switched to its third position, which allows the pressure fluid in the working cylinder 6 to be discharged into the pressure fluid container and a stress pulse is generated in the tool in the previously described manner. In the situation shown in FIG. 8 the pressure fluid continues to be fed behind the pressure intensifier piston 11 in the third position of the valve 8 , but if desired, it is possible to discontinue the feed of the pressure fluid in said situation. However, in this embodiment the pressure fluid feed behind the pressure intensifier piston 11 enhances the power of the stress pulse slightly.
In the above embodiments the invention is described only schematically and also the valves and the couplings associated with the pressure fluid feed are described only schematically. To implement the invention, it is possible to use any suitable valve solutions known per se, and for instance the valves 8 and 12 can constitute one single control valve as schematically indicated by a broken line 14 . The valves 8 and 12 can also be independent, separately controlled valves having one or more channels for feeding the pressure fluid into the working cylinder 6 and discharging it therefrom, respectively. Instead of the hydraulic pressure intensifier apparatus it is possible to use any mechanical or mechanical hydraulic apparatus for pushing the pressure intensifier piston 11 . Correspondingly, the pressure intensifier solution can also be applied to the embodiment of FIG. 3 and other embodiments of the invention defined in the claims.
In the above description and the drawings the invention is only presented by way of example and it is not restricted thereto in any way. It is essential, for providing a stress pulse in a tool, to use elastic and reversible, compressible material, whose compressibility is relatively low, which is stored in a separate energy storing space, and which is compressed by a desired force to create a desired stress state, i.e pressure, whereafter the energy storing material is abruptly released so that the pressure therein is discharged directly or indirectly to a tool end and further through the tool to the material to be broken. Instead of a liquid, the elastic and reversible, compressible material can be a substantially solid or porous material, such as rubber, polyurethane, elastomer or a similar elastic material, whose compression index is substantially lower than that of gases. The transmission piston can be separate from the tool, but in some cases it can also be an integral part of the tool. The transmission element, such as transmission piston, is pushed towards the energy storing material as described e.g. in connection with FIG. 2 until the desired level of press in the material and thus the desired state of stress has been reached, whereby the transmission element is in a position corresponding to the desired state of stress. Also, the transmission element, or transmission piston, can be pushed, as described for instance in connection with FIG. 8 , to a predetermined position, which is defined by shoulders or corresponding mechanical means, which stop the transmission element to a predetermined place with respect to the body of the percussion device irrespective of what is the state of energy stored in the energy storing material.
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A percussion device for a rock drilling machine or the like, which comprises means for providing an impact, i.e. a stress pulse, to a tool connected to the percussion device. The means for proving the stress pulse include a stress element ( 4 ) of liquid, which is supported to a body ( 2 ) of the percussion device and means for subjecting the stress element to pressure and correspondingly for releasing the stress element ( 4 ) abruptly, whereby the stress energy is discharged as a stress pulse to the tool in direct or indirect contact with the stress element.
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FIELD OF THE INVENTION
[0001] The present invention pertains to a process for measuring the inking during printing, in which integral measurements are carried out on the running paper web. The present invention also pertains to a device for carrying out the process. Furthermore, the present invention pertains to the regulation of the inking in web-printing presses. The present invention also pertains to a device for carrying out the process.
BACKGROUND OF THE INVENTION
[0002] Newspapers are produced predominantly according to the offset process. A plurality of paper webs are unwound from rolls, printed in the printing units and finally folded in the folding apparatus and cut. The inking can be set zone by zone in conventional inking systems. The presetting of the inking systems is based on the surface coverage of the printing plates, which is determined by means of so-called plate scanners, or can be calculated directly from the image data. The printer monitors the inking during the entire production and makes corrections in inking when necessary.
[0003] WO 96/12934 of Graphics Microsystems Inc., discloses a process for measuring the inking. In this or similar processes, a measuring element is recognized using video cameras and subjected to spectral measurement. The drawback of these processes is, first, the great technical effort and, second, the need to jointly print measuring elements on the web, which are subsequently cut off. The format of a newspaper is usually not trimmed, and it is therefore, in general, undesired to print measuring elements jointly. Therefore, such measurement processes or automatic ink regulating systems based on such processes have not yet been used in newspaper printing.
[0004] Another basic difficulty for the automatic regulation of inking arises from the complex dynamics of the conventional gap inking systems. For example, the inking must always be set zone by zone, the delay time with which an adjustment of the inking becomes effective on the printed web depends strongly on the ink take-off, and, moreover, the inking is affected in adjacent zones.
[0005] The production of printing plates is carried out in newspaper printing in the so-called preliminary printing stage. To do so, the original prepared in the editorial office of the newspaper is typically separated into four printing colors cyan, magenta, yellow and black. The color separations are reduced to half-tones after the separation, and pixel data, which represent the elements to be printed on the printing plate, which are exposed on the basis of these data, are obtained as a result.
[0006] Three-dimensional tristimulus values are transformed during the color separation into the four-dimensional color space C, M. Y, K. Depending on the type of separation, superimposed chromatic colors can be replaced to a certain extent or completely by black color. The type of separation should be known for corrections of the inking.
[0007] Changes also arise in the color effect of a paper web printed according to the web offset process when the amount of moisture fed in is changed. In fact, the establishment of a so-called ink-water balance requires a certain amount of experience in practice. Moreover, it depends on the type of paper and the printing style.
[0008] The visual evaluation of the color in the print is carried out in the three-dimensional color space, which corresponds to the human eye. On the other hand, there is a large number of adjusting possibilities to affect the color reproduction. As a result, the automatic regulation of the inking is made more difficult.
[0009] DE 198 22 662 A1 of MAN Roland Druckmaschinen AG proposes a process for operating a printing press, in which basic knowledge is obtained on the cooperation of operating media in the printing press by printing tests or during the production, it is stored in an expert system and used for the printing operation. An expert system is a “computer program system which stores all the material available on a special area, draws conclusions from same, and proposes solutions for problems of the area in question. The structure of expert systems and their use falls within the area of artificial intelligence” (cf. LexiRom 4.0, Microsoft Corp., 1999). Such systems typically have a dialog component, an explanation component, a knowledge acquisition component, a problem solving component, and a knowledge base. Such a system is difficult to operate and maintain. Besides the personnel for operating the printing press, it requires specialists from the area of information processing. An expert system is also not a closed regulatory circuit, it does not replace the expert, but is a tool to support the expert in processing complex problems by proposing solutions. To reduce the errors in the printing process, the applicant of the above-mentioned disclosure document proposes to reduce the complexity of the printing press by using a short inking system.
SUMMARY OF THE INVENTION
[0010] One object of the present invention is to provide an inexpensive process for color measurement on the web, in which no measuring elements need to be printed jointly.
[0011] According to the invention, a process is provided for measuring the inking in web printing in which a measuring head or a plurality of measuring heads performs/perform an integrating measurement of the light remitted by a printed material web in the direction of run of the material web. Device is also provided for measuring the inking in web printing, preferably for carrying out the measurement process in accordance with the invention The device includes at least one sensor element for receiving light that is remitted by a running, printed web of material, an adding or integrating means, which is connected to a sensor element, of which there is at least one, in order to determine the intensity of the light received, and a control, which presets the duration of reception of light and/or the duration of the addition or integration by means of the adding or integrating means for an adding or integrating intensity measurement of the remitted light in the direction of run of the web. Furthermore, another subject of the present invention is a process for the rapid regulation of the inking of a gap printing system. According to this aspect of the invention, actual values are generated by a process discussed above. Set points are calculated from the image data, forming integrals of the remission spectrum over the columns of the image and folding these with the measuring field function of a measuring head, or set points are formed from the measured actual values of pages that are considered to be good. The ink density is set by setting the ink feed or the damping agent feed. A device for regulating the ink density in web printing, preferably for carrying out the regulating process in accordance with one of the above claims, characterized in that set points are calculated from the image data.
[0012] The basic idea of the present invention is based on the fact that the inking of a printing press with gap inking system takes place zone by zone. One zone always corresponds to one strip of the printed image in the direction of the press. This circumstance is taken into account in the process according to the present invention insofar as an integral measurement of the colors on the web is carried out over a longitudinal strip. Whether a spectral color measurement or a densitometric measurement or another principle of measurement is used to evaluate the printed web is basically irrelevant.
[0013] Each measurement process for evaluating the optical effect of a surface is based on the fact that the radiation remitted from the surface is received by a measuring apparatus, in which the incident light is integrated. For example, free charges are produced in a fiber-optic light guide in electronic detectors in proportion to the effect of the light, unless the working range of the apparatus is exceeded. In the case of densitometric measurement, the incident light is separated by color filters before it is detected by photosensitive detectors. In the case of spectral measurement, the dispersion of a prism or a grid is utilized to image the components of different wavelengths onto a photosensitive semiconductor array in a locally resolved manner. The amount of incident light is integrated in the individual cells until saturation is reached.
[0014] If it is desirable to measure the optical effect of the surface of a moving object at a certain point, it is possible, e.g., to move the measuring head in relation to the object to be measured at equal velocity as long as the measuring operation lasts. It is usually simpler to use a flash lamp and thus send a large amount of radiation into the detector during the short duration of the flash. The integration times of the measuring apparatus are short in this case, so that the movement of the object during the measurement can be ignored.
[0015] In this case, the measured object is the running, printed web in a printing press. The image located thereon is repeated with the frequency of rotation of the printing cylinders. If a detector is placed in a fixed manner over the web, and the measurement is performed for the duration of one revolution of the cylinders, the radiation emitted from all locations along one strip in the direction of the press is integrated in the measuring head. The length of the strip corresponds to the revolution of the cylinder, and the width of the strip depends on the optical system of the detector. It is not absolutely necessary to image a sharp image strip into the detector. If the integral measurement of a periodic original is performed, as is the case in the case of the printing operation, over the duration of one period or over an integer multiple of the duration of the period, it is important to adjust the duration of the measurement to the duration of the period, the point in time at which the measurement begins being irrelevant in this case.
[0016] If the measurement is carried out over part of the duration of one period, e.g., over half of one period, it is necessary to know the point in time of the measurement.
[0017] Such an integral measurement can be advantageously broken down into a plurality of integral partial measurements following one another without delay and the results can be summed up.
[0018] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the drawings:
[0020] [0020]FIG. 1 is a schematic view of an arrangement for carrying out the process based on the example of a spectral measurement;
[0021] [0021]FIG. 2 is a schematic view showing a displacing unit in the X direction, at right angles to the direction of the press;
[0022] [0022]FIG. 3 is a view illustrating the local measuring behavior of a measuring head;
[0023] [0023]FIG. 3 b is a view illustrating the problem of the measuring field function for the two-dimensional case;
[0024] [0024]FIG. 4 a is an example for a spectral measurement showing saturation (Sat) of the photosensitive element;
[0025] [0025]FIG. 4 b is an example for a spectral measurement showing the amount of light must too low so as not to reach a high ratio of the measured signal to noise of the detector;
[0026] [0026]FIG. 4 c is an example for a spectral measurement showing the measurement selected to be such that a maximum is located in the spectrum just below the saturation limit of the detector;
[0027] [0027]FIG. 5 a is a schematic view of an example of a printed image showing the areas covered by ink;
[0028] [0028]FIG. 5 b is a graph showing the spectrum sum function S(X), which is obtained from the ink coverage;
[0029] [0029]FIG. 5 c is a graph showing the measuring field function Ψ, which arises from the properties of the measuring head and its positioning in relation to the web; and
[0030] [0030]FIG. 5 d is a graph showing the set point function T(X), which is formed by folding S with Ψ.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Referring to the drawings in particular, FIG. 1 shows a schematic arrangement for carrying out the process based on the example of a spectral measurement. The press 1 prints on a paper web 2 . A measuring head 3 is placed over the web 2 . The measuring head contains an illuminating means, which is connected to a light source 31 via a glass fiber line 32 . The light reflected by the web 2 is introduced into a spectrometer 33 via a glass fiber line 34 . The spectrometer is controlled by a computer 4 such that the measurements are adjusted to the speed of rotation. A measurement includes one or more partial measurements. The overall duration of the measurement is exactly the duration of one revolution of the cylinder or a multiple thereof As a result of the measurement, a spectrum is transmitted to the computer 4 . This spectrum is the integral of all remission spectra that are measured at the locations on the paper web that pass under the measuring head during the measurement. The measuring head can be positioned by means of a displacing unit at right angles to the direction of the press, and the positioning is likewise controlled by the computer 4 by means of the control line 41 .
[0032] [0032]FIG. 2 shows a sketch of a displacing unit in the X direction, at right angles to the direction of the press. The measuring head 3 with the optical connections 32 , 34 is mounted on a spindle 43 . The spindle drive 42 is controlled via the line 41 . The measuring head can thus be positioned at right angles to the direction of the press at any desired point over the paper web.
[0033] [0033]FIG. 3 a illustrates the local measuring behavior of a measuring head. In general, a measuring head detects a range of the width Bx. The optical effect of the object being measured in the detected range is not of equal intensity at all locations, and it can be weighted by a function Ψξ. Ψξ depends on the nature of the measuring head and the distance between the measuring head and the object being measured. This function will hereinafter be called the measuring field function.
[0034] [0034]FIG. 3 b illustrates the problem of the measuring field function for the two-dimensional case. The measuring field also has an extension in the Y direction, By, besides the extension in the X direction, Bx. Even though it is possible to design a measuring head by means of a suitable optical system such that the extension of the measuring field in the Y direction is restricted so greatly that this dimension of the measuring field function can be ignored, this is associated with increased technical effort or with a loss of sensitivity. A sharp limitation of the measuring field in the Y direction is not necessary for the process according to the present invention.
[0035] A remission spectrum is an intensity distribution as a function of the wavelength A. If it is measured in a spectrometer that breaks down the spectral range into n intervals, a vector r=[I(λ1), I(λ2), I(λ3), . . . I(λn)] is obtained. The remission spectrum at the location X can be considered to be a vector rX.
[0036] The spectrum R recorded by a measuring head with the measuring field function Ψ at the location X is obtained by integration:
R ( X ) = ∫ - B x / 2 B x / 2 r ( X + ξ ) · Φ ( ξ ) ξ .
[0037] In the 2 or 3-dimensional case:
R ( X , Y ) = ∫ - B x / 2 B x / 2 ∫ - B y / 2 B y / 2 r ( X + ξ , Y + ψ ) · Φ ( ξ , ψ ) ψ ξ
[0038] The fact described here on the basis of the example of a spectral measurement can be applied to any color measurement process commonly used in the graphics industry. In the case of a densitometric measurement, the vector r has only 3 or 4 dimensions.
[0039] If the object being measured is moving during the measurement, a further integration must be performed in order to describe the result of the measurement. The longer the measuring head remains at the points located on the path traveled during the measurement, the greater is the contribution of these points to the measured value. A simple case is obtained during the measurement of the duration T with a measuring head that is positioned in a fixed position over a printed paper web that is running at constant velocity V in the direction Y under the measuring head. If the measurement begins at the time t 0 and the measuring head is located at the point X 0 , Y 0 at this point in time, is obtained.
R = ∫ t0 t0 + T R ( X0 , Y0 + V ( t - t0 ) ) t .
[0040] A further simplification is obtained based on the periodicity of the printing operation. If the circumference of the printing cylinder is U, the remission spectra are repeated in the ideal case at this period, i.e., r(X,Y)=r(X,Y+U) in the direction of the press.
[0041] This periodicity can be applied to the measurement with one measuring head. R(X,Y)=R(X,Y+U) is obtained for each measuring field function.
[0042] Due to fact that the stretching of the paper changes during the run through the press, this relationship is not exact. However, a periodicity in time is obtained at constant speeds of rotation. Since the stretching of the web reaches steady states, the measurement over the duration of one revolution of the cylinder corresponds precisely to the measurement of one section length, even if the web is stretched. Measurement over a time T=U/V corresponds to the scanning of the web over one section length. Now,
R = ∫ t0 t0 + T R ( X0 , Y0 + V ( t - t0 ) ) t = ∫ 0 U R ( X0 , Y ) Y .
[0043] Thus, an integral measurement depends only on the measuring field function of the measuring head, the lateral measuring position X and the spectral remission r(X,Y) of the printed image. It is, in particular, independent from the point in time at which the measurement begins.
[0044] Thus, such a process yields reproducible measured values, which are locally resolved in one dimension, namely, at right angles to the direction of printing. Thus, the measuring method corresponds to the possibilities of setting the ink feed zone by zone in a printing press. However, it is also possible to use the process in presses that have so-called zone-free inking systems.
[0045] [0045]FIG. 4 shows examples for spectral measurements.
[0046] Each detector has an ideal working range. On the one hand, the incident radiation energy must not be too high so as not to bring about saturation Sat of the photosensitive element FIG. 4 a , but, on the other hand, the amount of light must not be too low FIG. 4 b so as not to reach a high ratio of the measured signal to noise of the detector. The strongest signal that can be measured during the remission measurement occurs when the white color of the paper is measured. A measurement of the whiteness of the paper may occur, e.g., during the pulling in of the web. Another possibility is to position the measuring head over the normally unprinted edge strip next to the printing area or between the individual pages, where the width of the measuring field function must be taken into account.
[0047] The time during which a measuring operation leads to the saturation of the defector varies depending on the light source. By performing one or more test measurements, the measurement is selected to be such that a maximum is located in the spectrum just below the saturation limit of the detector (FIG. 4 c ), e.g., at 90% of the saturation. The ideal measurement time is thus set. A reference spectrum 1 R ref =[I ref (λ1), I ref (λ2), I ref (λ3), . . . I ref (λn)] is obtained, which can be used to standardize the subsequent measurements. A standardized spectrum is obtained if the spectral values of a measurement are divided by the corresponding values of the reference spectrum:
R norm =[I (λ1)/ I ref (λ1), I (λ2)/ I ref (λ2), I (λ3)/ I ref (λ3), . . . I (λ n )/ I ref (λ n )].
[0048] Differences in the spectral sensitivity of the detector and of the light source are compensated by the standardization.
[0049] Once the ideal measurement time T ideal has been set, the actual measurement time T real must be determined from the cycle time for one printing operation T.
[0050] The cycle time of the printing operation is the duration of one printing operation, i.e., a single-time copying of the print original on the paper web. It is often equal to the duration of the period of one revolution of the printing cylinder in rotary printing presses. This is true especially if exactly one print original, e.g., an offset printing plate, is located on the circumference of the printing cylinder.
[0051] The cycle time of the printing operation is also equal to the duration of the period for one revolution of the printing cylinder in rotary printing presses that carry two printing plates one behind another on the circumference of the printing cylinder, as they are used, e.g., for printing newspapers, if the two printing plates carry different images and the printing press is operated in the collect-run production mode.
[0052] However, the cycle time may also be different from the duration of the period of one revolution of the printing cylinder. This may happen, e.g., in rotary printing presses used for printing newspapers, which carry two printing plates one behind another on the circumference of the printing cylinder, if the two printing plates carry the same image and the printing presses are operated in the double production mode. The cycle time of the printing operation may be equal to half the duration of the period of one revolution of the printing cylinder.
[0053] Consequently, depending on the mode of production, T=U/V and T=0.5*U/V is obtained for the circumference U of the cylinder and the press speed V, respectively. If the press speed is so low that the cycle time for one printing operation T is greater than the ideal measurement time T ideal , the measurement should be broken down into a plurality of partial measurements, whose values are subsequently added up. If the cycle time becomes short at high press speeds, the measurement may take place over a multiple of T. In principle, a measurement over a plurality of printing cycles may also be broken down into a plurality of measuring intervals in order to optimize the signal-to-noise ratio of the measuring head: The measurement is performed over K printing cycles and these are broken down into J intervals, where the rational K:J ratio approaches the ratio T ideal :T real . The measured value is thus formed from the sum of J measurements. For standardization, the spectrum must be divided by the measurement time T real and, in addition, by the reference spectrum.
[0054] It is thus achieved that the measuring head always operates in a favorable range.
[0055] The regulation of the ink density is used on the integral measurement of the remission spectrum, as was described above, or on an integral, densitometric measurement of the web. The necessary actual values are obtained as a result.
[0056] The set points are determined in the process according to the present invention for regulating the ink density from the separated pixel data, which are available after the reduction to half-tones of the original to be printed at the digital preliminary printing stage, or they are taken over from the actual values of printed pages considered to be good.
[0057] A method for calculating remission spectra was described by Hübler [HUB]. The scattering behavior of the substrate and the effect of the ink layers applied are taken into account here. The requirement for the calculation of the local remission spectra is that the different colors are transferred to the substrate without register error. To ensure this, it is possible to use a corresponding regulating system. Another possibility is the use of so-called satellite printing units, which have only small register errors due to their design.
[0058] What is novel in the basic idea of the process according to the present invention is that what are used as set points are not the local remission spectra, but the integral is determined over columns of the image in the direction of the press in this case as well. In addition, the measuring field function of the measuring head is taken into account in the calculation of the set points. The calculation of set points is performed, e.g., in two steps. The sum of all remission spectra of the pixels that form one column is formed from the separated pixel data reduced to half-tones in the first step, the scattering behavior in the paper and consequently the color of the pixels in the environment of a scattering radius having to be taken into account. An integral remission spectrum is thus obtained for each column of pixels. A column of pixels corresponds to a position X at right angles to the direction of the press. The result is a spectrum S as a function of the position X:
S:X→ρ,X S(x),
[0059] in which Xε[0,b] is the lateral measurement position on a web of width b and p is the mathematical space of the remission spectra that agree with the spectra obtained during a measurement in terms of the spectral range and the number of support points per spectrum. The function S will hereinafter be called the spectral sum function.
[0060] The measuring field function of the measuring head is taken into account in a second step. To do so, the measuring field function Ψ is folded with the spectral sum function S. A set point T is obtained for each position X as a result of this folding:
T ( X ) = ( S * Φ ) ( X ) = ∫ - B x / 2 B x / 2 Φ ( ξ ) · S ( X + ξ ) ξ
[0061] The regulation of the ink density is based on the comparison of the set points TX with the measured values RX.
[0062] Different printing colors differ precisely in that they absorb the radiations of different spectral ranges at different intensities. For example, the long-wave spectral range of the visible light is absorbed by cyan, whereas it is transparent to the printing color magenta. By narrowing the spectrum to certain ranges, color separations of the printed image can be obtained. This applies to both a measurement of the color and the precalculation of the set point from image data. If it is desirable to obtain information concerning a certain color, it is advantageous to measure at a location X at which this color is present and at which the corresponding color separation of the set value function TX has a flat shape. In ranges in which TX has an irregular shape, there is a risk that a small error in the positioning of the measuring head leads to a great error of measurement.
[0063] [0063]FIG. 5 shows a schematic example of a printed image and the generation of the set point function.
[0064] [0064]FIG. 5 a shows the areas covered by ink.
[0065] [0065]FIG. 5 b shows the spectrum sum function SX, which is obtained from the ink coverage.
[0066] [0066]FIG. 5 c shows the measuring field function Ψ, which arises from the properties of the measuring head and its positioning in relation to the web.
[0067] [0067]FIG. 5 d shows the set point function TX, which is formed by folding S with Ψ. It corresponds, in principle, to a smoothened spectral sum function. An analysis of TX permits favorable measuring locations to be set. There are ranges 1 in which TX displays great variations. The placement of the measuring head is critical here, and these measuring locations should therefore be possibly avoided. Furthermore, there is a range 2 in which the set point function has a uniform shape, even though the spectral sum function T is still subject to great variations. This uniformly can be attributed to the smoothening, which arises from the folding with the measuring field function. This circumstance contributes to the fact that, e.g., the measurement of print areas reduced to half-tones is possible if the width of the measuring field exceeds the grid width. Even though ranges without printing ink 3 show a uniform shape of the set point, they are unsuitable for the color measurement. The measured values are at their maxima, and they correspond to the reference measurement of the whiteness of the paper. Locations with high ink take-off 4 are, in principle, best suited for carrying out accurate color measurements. However, there may also be ranges 5 even here in which the set points vary with the position, which reduces the suitability of these locations for the measurement. Measurement is also possible in ranges of uniform, slight ink take-off 6 .
[0068] The accuracy of positioning of the measuring head should be advantageously more accurate than the width of the measuring width. The width of the measuring field should also be greater than the possible lateral displacements of the printed web in order to avoid errors in measurement that may arise from the relative positioning error between the measuring head and the web.
[0069] There are a large number of parameters that affect the color reproduction, especially in web offset. A good starting point can be created as a basis for the regulation if the printing press is set correctly and especially the position of the rollers of the inking system and the damping system can be kept constant. The production processes of the preliminary stage should also be standardized, especially the production of the plates. Furthermore, the printing press should make possible printing true to register, because register errors lead to color shifts, which cannot be compensated by the adjustment of the ink and water feed. Satellite printing units are suitable for this, or, e.g., presses of the so-called eight-up tower configuration, if measures are taken to compensate the stretching of the paper. Without such a starting point, on-line regulation of the ink density is unthinkable anyway, because errors in the preliminary printing stage can be compensated during printing to a low extent only, or presses with poor roller position or a high register inaccuracy are not suitable for quality printing anyway, for which the use of an ink density regulator is desirable.
[0070] If the requirements are met on the part of the preliminary printing stage and the printing press, it is sufficient to use the zone-by-zone ink feed and the damping agent feed for ink density regulation as final control elements of the control circuit.
[0071] The dynamics of a conventional gap inking system are complex and depend on the number, type and arrangement of the rollers used. However, it can be stated, in general, that the higher the ink take-off, the more rapidly adjustments on the ink management will become visible in the printed image. At low ink take-off, the adjustments become effective more slowly. The ink take-off varying at right angles to the direction of the press is taken into account by zone-by-zone ink feed. Traversing rollers ensure the lateral distribution of the ink. The correct setting of the zones becomes important at high ink take-off, while the zones become rather “blurred” at low ink take-off, because the macroscopic ink transport takes place more slowly in the direction of the press and the traversing rollers bring about a more intense lateral spreading of the ink.
[0072] The damping agent feed also affects the color reproduction, and there also is a dependence on surface coverage. If the amount of damping agent feed is too small, “toning” occurs, i.e., ink is transferred to nonprinting areas of the printing form. If the amount of damping agent feed is too large, there is a risk of “emulsification” of the ink, especially in the case of low ink take-off, which leads to uncontrollable phenomena. The damping agent feed is often set over the width of the page, but it may also be carried out zone by zone, but usually only a small number of zones are formed in this case.
[0073] According to one control strategy of the regulating process according to the present invention, a set of weighting parameters, according to which an adjustment of the ink screws or an adjustment of the damping agent feed is carried out, is determined depending on the zone-by-zone ink take-off of the individual printing inks and their respective overall ink take-off. By performing measurements at a plurality of points, it is possible to decide whether the damping agent feed or the ink feed must be set or whether a weighted adjustment of both manipulated variables is necessary.
[0074] The order of the measuring locations and the frequency with which measurements are performed at the respective measuring locations should also be selected as a function of the image according to the present invention. Locations with high ink take-off should be monitored more frequently, especially at the start of the production; this corresponds to the dynamics of the inking system, because these locations respond to adjustments more quickly. At locations with low ink take-off, the time intervals between two measurements may be longer, but it is advantageous to perform a plurality of measurements at locations with low ink take-off in order to achieve increased accuracy of the measurement by averaging. In fact, the differences to be expected from the reference measurement are small, so that a more accurate measurement becomes necessary than in the case of high ink take-off.
[0075] The present invention preferably pertains to web offset printing, especially wet offset, but it is not limited to offset printing, but it may be advantageously used in other printing processes as well. The material web is preferably a paper web as is the case with the especially preferred printing of large newspaper runs. However, in principle, the material of the web does not need to be paper, and the present invention may rather be used wherever high qualitative requirements are imposed on the printing process.
REFERENCES
[0076] WO 96/12934, “On-Press Color Measurement Method with Verification,” Runyan, S. et al., Graphics Microsystems, Inc., Oct. 19, 1995.
[0077] Offenlegungsschrift DE 198 22 662 A1, “Image Data-Oriented Printing Press and Process for Operating the Image Data-Oriented Printing Press,” Dilling, P., MAN Roland Druckmaschinen AG, Nov. 25, 1999.
[0078] [HUB] Hübler, A. C., “Structure of the Radiation Process in Autotype Half-tone Printed Images,” Dissertation at the Institut für Technologie und Planung Druck, Berlin 1992.
[0079] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A process is provided for measuring the inking in web printing, wherein a measuring head or a plurality of measuring heads performs/perform an integrating measurement of the light remitted from a printed web of material in the direction of run of the web of material. A device is also provided for measuring the inking in web printing. The device includes at least one sensor element for receiving light, which is remitted by a running, printed web of material, an adding or integrating device, which is connected to a sensor element, of which there is at least one, in order to determine the intensity of the light received and a control, which presets the duration of reception of light and/or the duration of the addition or integration by means of the adding or integrating means for an adding or integrating intensity measurement of the remitted light in the direction of run of the web.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 60/713,570, filed Sep. 1, 2005, incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates generally to the field of testing hydrocarbon-bearing formations, and more particularly to methods, systems and apparatus useful in such operations.
[0004] 2. Related Art
[0005] Coiled tubing is a technology that has been expanding its range of application since its introduction to the oil industry in the 1960's. Its ability to pass through completion tubulars and the wide array of tools and technologies that can be used in conjunction with it make it a very versatile technology, and this versatility is the core of this invention. Recent advances in coiled tubing allow real-time control of downhole equipment, transmission of measurement data and isolation of individual zones within the reservoir.
[0006] Typical coiled tubing apparatus includes surface pumping facilities, a coiled tubing string mounted on a reel, a method to convey the coiled tubing into and out of the wellbore, and surface control apparatus at the wellhead. During the spooling process the coiled tubing is plastically deformed as it comes off the reel and is straightened by the injector as it is run into the well. The coiled tubing will expand slightly under the influence of differential pressure.
[0007] One typical method of testing and evaluating reservoirs is drill-stem testing. Another is wireline testing. Reservoir boundaries, skin and permeability information are needed to optimize production and reservoir development. Problems arise because of commingled flow.
[0008] Unfortunately, drill-stem testing requires removing existing completions, and includes the cost of bringing a rig to convey individual sections of drillpipe. Drill-stem testing also does not lend itself to real-time data collection during the testing operation. Wireline testing includes the necessity to kill the well to convey the wireline tool, which is undesirable, and the short interval that can be tested is frequently unsatisfactory.
[0009] Multiple patents exist for reservoir testing using concentric coiled tubing. Reservoir fluid is returned up the innermost layer and well-control fluid is pumped in the outermost layer of the concentric tubing. Sophisticated valves and flow apparatus are required at the surface to maintain well control as the reservoir fluid is diverted into the surface production facilities. The weight and cost of the concentric coiled tubing limits commercial application.
[0010] There remains a need for methods and apparatus to test and evaluate reservoirs without having to remove existing completion equipment in the wellbore. There is also a need for methods and apparatus to test and evaluate individual zones within a reservoir including testing of those zones that would not normally flow without artificial lift. Methods and apparatus that may provide a stable amount of hydrostatic lift to a reservoir zone are desired, as well as methods and apparatus for reliably conveying formation fluids from the interior of coiled tubing to the annulus around coiled tubing at some point higher in the string. There is also a need for valve apparatus at the base, or anywhere between the surface and the base of a coil of coiled tubing, and there is a need for data communication to the valve apparatus to find out what is going on at or near the valve apparatus.
SUMMARY OF THE INVENTION
[0011] An embodiment of the present invention provides a method of testing a multi-zone reservoir while reservoir fluids are flowing from within a wellbore. The method comprises the steps of: running coiled tubing into the wellbore; activating a zonal isolation apparatus to isolate at least one zone; allowing fluid to flow from the isolated zone; and measuring the downhole flow and pressure of the fluid flowing from the isolated zone.
[0012] Another embodiment of the present invention provides a method of testing a multi-zone reservoir while reservoir fluids are flowing from within a wellbore. In this embodiment, the method comprises the steps of: running coiled tubing into the wellbore; setting a first isolation apparatus to prevent reservoir fluid from flowing to surface; activating a zonal isolation apparatus below the first isolation apparatus to isolate a first zone; allowing fluid to flow from the first zone; measuring the downhole flow and pressure of the fluid flowing from the first zone; and diverting the fluid flow from the first zone to the annulus above the first isolation apparatus.
[0013] Yet another embodiment of the present invention provides an apparatus for testing reservoir fluids while they are flowing from a wellbore. The apparatus comprises: coiled tubing; a straddle system of packers activated to isolate a reservoir zone, the straddle system conveyed and positioned by the coiled tubing; a surface controlled valve system that enables fluid pumped from the surface to flow into the wellbore annulus above the straddle system of packers, enables fluid pumped from the surface to flow into a zone isolated by the straddle system of packers, and enables fluid flowing from the isolated zone of the reservoir to flow into the annulus above the straddle system of packers; and a measurement apparatus to provide flow measurements for fluid flowing from the isolated zone.
[0014] The various aspects of the invention and permutations thereof will become more apparent upon review of the brief description of the drawings, the detailed description of the invention, and the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The manner in which the objectives of the invention and other desirable characteristics may be obtained is explained in the following description and attached drawings in which:
[0016] FIG. 1 is a schematic illustration of a prior art coiled tubing apparatus used for well treatment operations;
[0017] FIG. 2 is a schematic illustration of a prior art drill-stem test apparatus used for well treatment operations;
[0018] FIG. 3 is a schematic illustration of a prior art wireline testing apparatus used for reservoir evaluation;
[0019] FIG. 4 is a schematic illustration of a prior art production logging operation used for reservoir testing that allows hydrocarbons to return to the surface exterior to spoolable tubing, with or without artificial gas lift;
[0020] FIG. 5 illustrates schematically a prior art improvement to the apparatus of FIG. 4 ;
[0021] FIG. 6 illustrates schematically in side elevation, partially in cross section, a communication system using a bundle of optical fibers inside a metal tube that has been inserted into spoolable tubing. The optical fibers transmit data but no power. The downhole sensors are powered by a;
[0022] FIG. 7 illustrates schematically an apparatus of the invention allowing a spoolable connector to be broken into two and a component inserted therein between;
[0023] FIG. 8 illustrates schematically a spoolable testing system of the invention having a valve for diverting fluid, the valve positioned intermediate of the surface and the base of the coiled tubing, plus a downhole component with isolation and sensors, but that commingles fluid from a zone being tested with fluid from a zone above the zone being tested;
[0024] FIG. 9 illustrates schematically a spoolable testing apparatus of the invention having a valve for diverting fluid, the valve positioned intermediate of the surface and the base of the coiled tubing, plus a downhole component with valves and sensors for reservoir testing, illustrating an embodiment of an apparatus of the invention inside a monobore completion with and without gas lift that does not commingle fluid from a zone of interest with fluid from other zones;
[0025] FIG. 10 illustrates schematically a spoolable testing apparatus of the invention having a valve for diverting fluid, the valve positioned intermediate of the surface and the base of the coiled tubing, plus a downhole component with valves and sensors for reservoir testing, illustrating a testing system through production tubing;
[0026] FIG. 11 illustrates schematically a zoned testing apparatus of the invention that removes the requirement for an intermediate diverter section; instead, a downhole sensor apparatus is included together with a communication system that can transmit downhole data in real-time during the testing;
[0027] FIG. 12 illustrates schematically an apparatus of the invention able to transmit flow data to the surface; reservoir flow is diverted into an interior pathway within a bottomhole assembly, and a venturi or spinner is included and flow data transmitted to the surface; and
[0028] FIG. 13 is a schematic illustration of a method for testing of the invention including the steps of running spoolable tubing into the wellbore, providing zonal isolation and withdrawing formation fluid from the isolated zone of the reservoir.
[0029] It is to be noted, however, that the appended drawings are not to scale and illustrate only typical embodiments of this invention, and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0030] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it may be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
[0031] By “wellbore”, we mean the innermost tubular of the completion system. “Surface”, unless otherwise noted, means very generally out of the wellbore, above or at ground level, and generally at the well site, although other geographic locations above or at ground level may be included. “Tubular” and “tubing” refer to a conduit or any kind of a round hollow apparatus in general, and in the area of oilfield applications to casing, drill pipe, metal tube, or coiled tubing or other such apparatus. By “well servicing”, we mean any operation designed to increase hydrocarbon recovery from a reservoir, reduce non-hydrocarbon recovery (when non-hydrocarbons are present), or combinations thereof, involving the step of pumping a fluid into a wellbore. This includes pumping fluid into an injector well and recovering the hydrocarbon from a second wellbore. The fluid pumped may be a composition to increase the production of a hydrocarbon-bearing zone, or it may be a composition pumped into other zones to block their permeability or porosity. Methods of the invention may include pumping fluids to stabilize sections of the wellbore to stop sand production, for example, or pumping a cementations fluid down a wellbore, in which case the fluid being pumped may penetrate into the completion (e.g. down the innermost tubular and then up the exterior of the tubular in the annulus between that tubular and the rock) and provide mechanical integrity to the wellbore. As used here in the phrases “treatment” and “servicing” are thus broader than “stimulation”. In many applications, when the rock is largely composed of carbonates, one of the fluids may include an acid and the hydrocarbon increase comes from directly increasing the porosity and permeability of the rock matrix. In other applications, often sandstones, the stages may include proppant or additional materials added to the fluid, so that the pressure of the fluid fractures the rock hydraulically and the proppant is carried behind so as to keep the fractures from resealing. The details are covered in most standard well service texts and are known to those skilled in the well service art so are omitted here.
[0032] As used herein, the terms “BOP” and “blow-out preventer” are used generally to include any system of valves at the top of a well that may be closed if an operating crew loses control of formation fluids. The term includes annular blow-out preventers, ram blow-out preventers, shear rams, and well control stacks. By closing this valve or system of valves (usually operated remotely via hydraulic actuators), the crew usually regains control of the well, and procedures may then be initiated to increase the mud density until it is possible to open the BOP and retain pressure control of the formation. A “well control stack” may comprise a set of two or more BOPs used to ensure pressure control of a well. A typical stack might consist of one to six ram-type preventers and, optionally, one or two annular-type preventers. A typical stack configuration has the ram preventers on the bottom and the annular preventers at the top. The configuration of the stack preventers is optimized to provide maximum pressure integrity, safety and flexibility in the event of a well control incident. The well control stack may also include various spools, adapters and piping outlets to permit the circulation of wellbore fluids under pressure in the event of a well control incident.
[0033] A “lubricator”, sometimes referred to as a lubricator tube or cylinder, provides a method and apparatus whereby oilfield tools of virtually any length may be used in coiled or jointed tubing operations. In some embodiments use of a lubricator allows the coiled tubing injector drive mechanism to be mounted directly on the wellhead. An oilfield tool of any length may be mounted within a closed-end, cylindrical lubricator which is then mounted on the BOP. Upon establishment of fluid communication between the injector and the BOP and wellhead by opening of at least one valve, the oilfield tool is lowered from the lubricator into the wellbore with a portion of the tool remaining within the wellhead adjacent first seal rams located in the BOP which are then closed to engage and seal around the tool. The lubricator may then be removed and the injector head positioned above the BOP and wellhead. The tubing string is extended to engage the captured tool and fluid and/or electrical communication is established between the tubing and the tool. The injector drive mechanism (already holding/attached to the tubing string) may then be connected to the BOP or wellhead and the first seal rams capturing the tool are released and fluid communication is established between the wellbore and the tubing injector drive head. The retrieval and removal of the oilfield tool components are effected by performing the above steps in reverse order.
[0034] By “pumping system” we mean a surface apparatus of pumps, which may include an electrical or hydraulic power unit, commonly known as a powerpack. In the case of a multiplicity of pumps, the pumps may be fluidly connected together in series or parallel, and the power conveying the communication line may come from one pump or a multiplicity. The pumping system may also include mixing devices to combine different fluids or blend solids into the fluid, and the invention contemplates using downhole and surface data to change the parameters of the fluid being pumped, as well as controlling on-the-fly mixing.
[0035] By the phrase “surface acquisition system” is meant one or more computers at the well site, but also allows for the possibility of a networked series of computers, and a networked series of surface sensors. The computers and sensors may exchange information via a wireless network. Some of the computers do not need to be at the well site but may be communicating via a communication system. In certain embodiments of the present invention the communication line may terminate at the wellhead at a wireless transmitter, and the downhole data may be transmitted wirelessly. The surface acquisition system may have a mechanism to merge the downhole data with the surface data and then display them on a user's console.
[0036] In exemplary embodiments of the invention, advisor software programs may run on the acquisition system that would make recommendations to change the parameters of the operation based upon the downhole data, or upon a combination of the downhole data and the surface data. Such advisor programs may also be run on a remote computer. Indeed, the remote computer may be receiving data from a number of wells simultaneously.
[0037] Communication lines useful in the invention may have a length much greater than their diameter, or effective diameter (defined as the average of the largest and smallest dimensions in any cross section). Communication lines may have any cross section including, but not limited to, round, rectangular, triangular, any conical section such as oval, lobed, and the like. The communication line diameter may or may not be uniform over the length of the communication line. The term communication line includes bundles of individual fibers, for example, bundles of optical fibers, bundles of metallic wires, and bundles comprising both metallic wires and optical fibers. Other fibers may be present, such as strength-providing fibers, either in a core or distributed through the cross section, such as polymeric fibers. Aramid fibers are well known for their strength, one aramid fiber-based material being known under the trade designation “Kevlar”. In certain embodiments the diameter or effective diameter of the communication line may be 0.125 inch (0.318 cm) or less. In one embodiment, a communication line would include an optical fiber, or a bundle of multiple optical fibers to allow for possible damage to one fiber. Commonly assigned U.S. patent application Ser. No. 11/111,230 entitled “Optical Fiber Equipped Tubing and Methods of Making and Using”, filed Apr. 21, 2005, discloses one possible communication line wherein an Inconel tube is constructed by folding it around the optical fiber and then laser-welding the joint to close the tube. The resulting construction is referred to as an optical fiber tube, and is very rugged and may withstand severely abrasive and corrosive fluids, including hydrochloric and hydrofluoric acids. Fiber optic tubes are also available from K-Tube, Inc., of California, USA. An advantage of fiber optic tubes of this nature is that it is straightforward to attach sensors to the bottom of the tube. The sensors may be machined to be substantially the same or smaller diameter than the fiber optic tube, which minimizes the likelihood of the sensor getting ripped off the end of the tube during conveyance. Fiber optic tubes are not inexpensive, however, and thus certain embodiments of the invention comprise retrieving the sensors by reverse spooling so that the tube may be reused. The reverse spooling may be controlled by the surface acquisition system, but also may be a standalone apparatus added after the stimulation process is complete.
[0038] In an alternative embodiment, the communication line may comprise a single optical fiber having a fluoropolymer or other engineered polymeric coating, such as a Parylene coating. The advantage of such a system is the cost is low enough to be disposable after each job. One disadvantage is that it needs to be able to survive being conveyed into the well, and survive the subsequent fluid stages, which may include proppant stages. In these embodiments, a long blast tube or joint comprising a very hard material, or a material coated with known surface hardeners such as carbides and nitrides may be used. The communication line would be fed through this blast tube or joint. The length of blast joint may be chosen so that the fluid passing through the distal end of the joint would be laminar. This length may be dozens of feet or meters, so the blast joint may be deployed into the wellbore itself. In embodiments where the communication line is a single fiber, the sensing apparatus may need to be very small. In these embodiments, nano-machined apparatus that may be attached to the end of the fiber without significantly increasing the diameter of the fiber may be used. A small sheath may be added to the lowest end of the fiber and cover the sensing portion so that any changes in outer diameter are very gradual.
[0039] Referring now to the figures, FIG. 1 is a schematic block diagram, not to scale, of a prior art system embodiment used to deploy a coiled tubing string into a well. (The same numerals are used throughout the drawing figures for the same components unless otherwise indicated.) Illustrated in FIG. 1 is a coiled tubing 22 being unwound from a coiled tubing reel 20 by an injector 26 through a gooseneck 24 , as is known in the art. An apparatus (not illustrated) may be provided in any number of positions that may be useful in taking geometric measurements of the coiled tubing. Coiled tubing 22 is spoolable and can be run in hole (RIH), and pulled out of hole (POOH), of a live well because of well-control apparatus at the surface. Reservoir fluids can return up the annulus between coiled tubing 22 and the wellbore (not illustrated in FIG. 1 ).
[0040] Although coiled tubing is useful for a variety of functions at a well site, primarily for its usefulness in being able to convey fluids into and out of a well, well control can be an issue, especially in so-called reverse flow situations, where production fluids may be allowed to flow up through the tubing toward the surface. Further, coiled tubing is subject to plastic deformation during use and pinhole defects and other defects are not uncommon. Concentric coiled tubing may be used to allow a reservoir fluid to return to the surface but it has significant operational issues, including safely diverting the fluids at the surface from the reel of concentric coil to the production facilities.
[0041] In practice, if reservoir fluids are desired at the surface, they are most typically conveyed through more robust tubing such as used during drill-stem testing. In this case, as illustrated in FIGS. 2A-2B , drill pipe is typically used to convey a system of packers. FIGS. 2A and 2B are substantially the same as FIGS. 1A and 1B from assignee's U.S. Pat. No. 4,320,800. For conducting a test of an interval of the well, the running-in string 10 of drill pipe or tubing is provided with a reverse circulating valve 11 of any typical design, for example a valve of the type illustrated in U.S. Pat. No. 2,863,511, assigned to the assignee of this invention. A suitable length of drill pipe 12 is connected between the reverse circulating valve 11 and a multi-flow evaluator or test valve assembly 13 that functions to alternately flow and shut-in the formation interval to be tested. A preferred form of test valve assembly 13 is illustrated in U.S. Pat. No. 3,308,887, also assigned to the assignee of this invention. The lower end of the test valve 13 is connected to a pressure relief valve 14 that is, in turn, connected to a recorder carrier 15 that houses a pressure recorder of the type shown in the assignee's U.S. Pat. No. 2,816,440. The recorder functions to make a permanent record of fluid pressure versus lapsed time during the test in a typical manner. The recorder carrier 15 is connected to the upper end of a screen sub 16 that serves to take in and to exhaust well fluids during operation of an upper packer inflation pump assembly 17 to which the lower end of the screen sub is connected. The pump assembly 17 , which together with the various other component parts of the tool string typically includes inner and outer telescoping members and a system of check valves arranged so that well fluids are displaced under pressure during upward movement of the outer member with respect to the inner member, and are drawn in via the screen sub 16 during downward movement. Thus a series of vertical upward and downward movements of the running-in string 10 is effective to operate the pump assembly 17 and to supply pressurized fluids for inflating the upper packer to be described below.
[0042] The lower end of the pump assembly 17 is coupled to an equalizing and packer deflating valve 18 that can be operated upon completion of the test to equalize the pressures in the well interval being tested with the hydrostatic head of the well fluids in the annulus above the tools, and to enable deflating the upper packer element to its normally relaxed condition. Of course an equalizing valve is necessary to enable the packers to be released so that the tool string can be withdrawn from the well. Valve 18 is connected to the upper end of a straddle-type inflatable packer system shown generally at 19 , the system including upper and lower inflatable packers 21 A and 21 B connected together by various components including elongated spacer sub 7 . Inflatable packers 21 A and 21 B each include an elastomeric sleeve that is normally retracted but which can be expanded outwardly by internal fluid pressure into sealing contact with the surrounding well bore wall. The length of spacer sub 7 is selected such that during a test upper packer 21 A is above the upper end of the formation zone of interest, and lower packer 21 B is below the interval. Of course when the packer elements are expanded as illustrated in FIG. 2A , the well interval between the elements is isolated or sealed off from the rest of the well bore so that fluid recovery from the interval can be conducted through the tools described above and into drill pipe 12 .
[0043] A rotationally operated pump assembly 23 that is functionally separate from upper pump assembly 17 is connected between the two packers and adapted to supply fluid under pressure to lower packer 21 B for inflating the same into sealing engagement with the well bore wall in response to rotation of pipe string 10 extending upwardly to the surface. Pump 23 has its lower end connected to an intermediate packer deflating valve 8 that functions when operated at the end of a test to cause packer 21 B to deflate. Lower packer assembly 21 B is generally similar in construction to upper assembly 21 A, and has its lower end connected to a deflate-drag spring tool 25 having means 9 frictionally engaging the well bore wall in a manner to prevent rotation so as to enable rotary operation of pump assembly 23 . Tool 25 may also include a valve that is opened at termination of a test to insure deflation of element 21 B.
[0044] If desired, another recorder carrier 27 may be connected to the lower end of drag tool 25 and arranged via an appropriate passageway to measure directly the formation fluid pressure in the isolated interval to enable a determination by comparison with the pressure readings of the recorder in upper carrier 15 whether the test passages and ports have become blocked by debris or the like during the test. Also, though not illustrated in FIG. 2 , it will be appreciated that other tools such as a jar and a safety joint may be incorporated in the string, for example between test valve assembly 13 and pump assembly 17 , in accordance with typical practice.
[0045] As shown rather schematically in FIG. 2A , the pipe string 10 typically extends upwardly to the surface where it is suspended for handling within a derrick D by typical structure such as a swivel S, traveling block B and cable C extending between the traveling block and the crown block S′ at the top of the derrick. The dead line of the cable has a transducer such as a load cell thereon to sense the weight of the drill string and the tools in the borehole. The output of the transducer is coupled to a weight indicator W that provides the rig operator with a visual indication of the precise amount of weight being supported by the cable and the derrick at all times. The line end of the cable extends to a drawworks that is used in typical manner to raise and lower the pipe as desired.
[0046] In operation, formation fluid is allowed to flow between packers, then to the surface through the drill pipe and from there to testing and production facilities. The drill pipe cannot be readily moved during this operation from one zone to the next, because an individual joint of pipe cannot be removed from the string without first killing the well. The jointed sections of pipe are also not spoolable so running in and out of the wellbore is time consuming.
[0047] Isolation techniques can be conveyed rapidly to the zone of interest when the isolation packers are lowered on a slickline or wireline cable. In this case, no reservoir fluids can be allowed to return to the surface because of the inability to provide well control across the heptacable.
[0048] FIG. 3 is a schematic illustration of a prior art wireline testing apparatus used for reservoir evaluation. Downhole measurements of flow and pressure are used to derive reservoir properties such as skin, permeability and reservoir extent. Illustrated in FIG. 3 , not to scale, is a partial cross-sectional view of a communication slick line or wire line, designated as 32 . Communication line 32 is usually kept spooled on a drum 34 kept some distance away from wellhead 48 . Typically an operator sits in an operator station 36 . Communication line 32 passes over sheaves 37 and 38 prior to passing into the top of a lubricator or stuffing box 40 . Lubricator or stuffing box 40 forms the pressure barrier around communication line 32 at its entry point. The remainder of the parts shown complete the well control stack, such as connectors 42 and 46 , and BOPs 44 .
[0049] When there is sufficient bottom-hole pressure, formation fluids flow naturally into the wellbore and upwardly to the surface. Flow characteristics of the reservoir can be simply determined either by gauging at the surface or by lowering a production logging tool into the wellbore. Some difficulty arises, however, when there is insufficient bottom-hole pressure to produce wellbore fluids to the surface. The hydrostatic column of fluid within the wellbore restricts reservoir fluid entry to the formation face or into the wellbore through the perforations. In order to overcome this hydrostatic column and produce fluids from the well, it is well known in the art to provide “artificial lift” of fluids by injecting a gas, usually nitrogen, into the wellbore at a depth sufficient to artificially lift wellbore fluids to the surface.
[0050] FIG. 4 illustrates one common way of achieving artificial lift utilizing nitrogen injection, as described in U.S. Pat. No. 3,722,589. The '589 patent describes an apparatus that allows spoolable tubing to be run into the pipe and which allows reservoir fluids to flow to the surface while production measurements are taken. The apparatus may comprise a hydraulic production logging tool in memory mode. The tool measures fluid flow rate and pressure, as well as other parameters such as viscosity, pH, and the like. The production logging tool is lowered to the zone of interest on spoolable tubing. No zonal isolation is possible. Nitrogen or other fluid may be pumped down the coiled tubing to an exit port some distance down the coiled tubing. The gas lifts the reservoir fluids, and the gas exits at some desired point along the tubing.
[0051] This technique utilizes coiled tubing which is stored as a continuous length of small diameter pipe on a reel located at the surface. The tubing is injected into the wellbore by well-known coiled tubing operations employing a tubing injector head located at or near the wellhead. Once the remote end of the coiled tubing has reached the proper depth for gas injection, it is a relatively simple matter of pumping the gas through the coiled tubing to produce the desired artificial lift.
[0052] Referring to FIG. 4 , a well 50 has therein one or more casings 51 lining the wellbore, and may have other pipes, casings, or tubing therein as required, all as well known in the art. Above the wellbore, there is provided a well head 48 which may be of any form employed in the art, the wellhead including devices for suspending pipes in the wellbore, valves, and valve-controlled outlets as is known. Above the wellhead there is typically a BOP 42 or other device through which a pipe string may be run without leakage or pressure from within the well. A tubing injector device 26 is provided, as well as a curved tubing guide 24 . Tubing injector device 26 is typically supported by a frame 54 , and coiled tubing 22 is typically stored on a reel 20 , which may be skid mounted or, as illustrated in FIG. 4 , carried on a truck 53 so as to be moveable from job site to job site. Liquid nitrogen may be pumped by a pump 56 through a heater 57 to produce high pressure nitrogen gas which is then delivered through a conduit 55 to coiled tubing 22 by way of hub flow connections of reel 20 . Wellbore 10 will in most cases contain a liquid having a level 60 in the well. For displacement of the liquid form the well, the end 22 a of coiled tubing 22 is injected into the wellbore by injector 26 to a position somewhat below liquid surface 60 . As the lower end 22 a of coiled tubing 22 moves downward in the well, gaseous nitrogen is continuously or discontinuously introduced at a rate so as to purge and circulate incremental portions of the liquid upwardly from the well through the annulus of a well pipe such as casing 51 . The liquid is evacuated through an outlet 63 of the well head. After the fluid has been removed from the well, a pressure draw down exists on a reservoir 62 at the lower portion of the well. Casing perforations 61 are provided as known so that fluid communication from reservoir 62 may exist.
[0053] Attempts have been made to log the flow within a wellbore in order to determine various reservoir parameters during the production of wellbore fluids by artificial lift utilizing gas injection with coiled tubing. Some difficulties have been noted in interpreting the data received. One patentee noted this was possibly due to the nature of the apparatus used for such logging, theorizing that the logging tool, typically mounted on the coiled tubing immediately below the gas injection orifice, experiences nitrogen bubbles entrained in the wellbore fluid which is passing through the propeller flow meter of the logging tool. Additional theory is that the hydrodynamic effects resulting from the injection of the gas into the wellbore fluid may cause swirls, eddies and the like which may also have an adverse effect on the accuracy of the measurement as determined by the flow meter propeller. Also, due to the size of the pumping equipment commonly employed with coiled tubing, it is necessary to pump relatively large amounts of gas through the apparatus, a condition which may not facilitate the production of the best data in conjunction with a production logging tool attached to the gas injection tool on coiled tubing.
[0054] FIG. 5 illustrates schematically a prior art improvement to the apparatus of FIG. 4 ; as described in U.S. Pat. No. 4,984,634. The '634 patent describes a gas injector tool 70 having at least one gas port 72 located generally on the lower end of a string of coiled tubing 22 within a wellbore 50 having a well casing 51 . With the injection of a gas such as nitrogen through coiled tubing 22 and out into wellbore 50 through gas port 72 , fluids within wellbore 50 will be artificially lifted to flow upwardly within the wellbore as is well known in the art. In accordance with the '634 patent, gas injection tool 70 has connected to its lowermost end an adaptor member 75 which acts to interconnect gas injection tool 70 with a first wireline cable head connector 76 . A wireline 74 , allowing electrical communication from the surface to the cable head, passes through coiled tubing 22 , gas injector tool 70 , adaptor 75 and is connected to the electrical connectors within the first cable head 76 . Below first cable head 76 , a support spacer 79 extends downwardly to a second cable head connector 77 and establishes electrical communication between first cable head 76 and second cable head 77 . Second cable head 77 is then connected to a production logging tool 78 in accordance with standard wireline logging connection procedures. Production logging tool 78 can then log the flow rate of fluids upwardly within wellbore 50 . As stated previously, the length of the spacer member 26 may be adjusted to a length which will accomplish the desired ends of both removing the production logging tool from the effects of gas injection and allow for the adjustment of the flow rate of wellbore fluids within wellbore 50 relative to an available flow rate of gas through the coiled tubing and out port 72 of gas injection tool 70 . Generally, the length of the spacer member 79 is varied between about 100 feet to in excess of 1000 feet (about 30 to 300 m).
[0055] FIG. 6 illustrates schematically in side elevation, partially in cross section, a communication system using a bundle of optical fibers inside a metal tube that has been inserted into spoolable tubing. The optical fibers transmit data but no power. The downhole sensors are powered by a;Illustrated is a coiled tubing 22 having an optical fiber carrier conduit or tube 86 , which may be straight as illustrated. Tube 86 routes one or more optical fibers 92 through coiled tubing 22 . Optical fiber termination end 89 is illustrated having four optical fiber terminations, while a second end includes a cartridge seal 93 , and a mechanical hold and seal 87 , which in this embodiment is a compression style fitting. This series of seals 87 , 93 , and a bulkhead seal (not illustrated) sealingly connects body 88 to optical fiber carrier 86 . Optical fiber 92 may have slack, which may be wound around a fiber optic termination support rod 94 for a portion of its length. A bare fiber optic bulkhead 96 is provided which functions to seal off fiber carrier 86 from well bore and treatment fluids in the event that the coiled tubing head or bottom hole assembly has a failure. A series of connectors 80 A, 80 B and 82 may be employed as illustrated. Connector 80 B may be a threaded collar. Note that a fluid flow path is provided through coiled tubing 22 , connectors 80 A, 80 B, and 82 , and through coiled tubing head 82 at 98 . Item 85 is a protector and could be replaced with a variety of components.
[0056] The communication system may be an electrical cable or a system of optical fibers inside a metal tube such as illustrated in FIGS. 6A and 6B just described. An advantage of using a tube containing optical fibers is that the tube takes up less space inside the coiled tubing and causes less drag. In particular, the tube can be inserted into the coiled tubing before the operation. In the case when the communication system includes an optical fiber, the pressure sensor may also be an optical pressure sensor. A light source such as a laser is included on the coiled tubing reel, which activates the pressure sensor.
[0057] It is a feature of this invention to extend the communications system past the point where the nitrogen exits down to the production logging tool. In this case, the reservoir flow and pressure measurements are available in real-time, which greatly enhances the value to the customer. In one embodiment, the apparatus for this requires a lower communication system from the production logging tool to the nitrogen exit, wherein a communications bulkhead may be provided to pass data from directly below the nitrogen valve to directly above it. The upper communication system then conveys the data from there to the surface.
[0058] It is also a feature in this invention to provide means for deploying the production logging system without having to kill the well before and after the operation. As illustrated in FIG. 5 there is an exit point 72 in the coiled tubing through which the nitrogen is pumped; this means that there could be well control problems. What is needed is a way to insert a check-valve above the hole 72 , so that nitrogen could be pumped down the coiled tubing but reservoir fluids could not enter. The embodiment illustrated in FIG. 7 presents a solution to this problem. Illustrated is a coiled tubing reel 20 having an upper portion of coiled tubing 22 A spooled thereon. An upper spoolable connector 102 connects coiled tubing 22 A with a non- spoolable check valve 104 , which is in turn connected to a bottom spoolable connector 103 , and finally to a lower portion 22 B of coiled tubing. The latter is closed by the production logging tool (not illustrated), and is run in hole until spoolable connector 103 is at the level of the well-head. Neutral kill-fluid such as brine or water is pumped into the coiled tubing to fill it to that point. The rams are closed around the coiled tubing and the spoolable connector is then separated into two. Note that two barriers for well control exist: the coiled tubing itself plus the kill-fluid. A new device, such as a check valve apparatus 104 may then be added to lower portion 22 B of coiled tubing. The new device may have an exit port for nitrogen and a double-flapper check-valve above it. The upper spoolable connector 102 is then attached to the newly installed device. The assembly can now be safely run into the wellbore.
[0059] FIG. 7 illustrates schematically an apparatus of the invention allowing a spoolable connector to be broken into two and a component inserted therein between; While the type of connection is not illustrated, threaded connections, turnbuckle connections, or other similarly functioning connection type may be used. One advantage is to provide for the introduction of a check-valve or other component by having a system that can be shipped to the rig as two coils spooled together. They are unspooled at the rig and a valving apparatus is inserted which allows the system to be deployed under pressure.
[0060] Another feature of the invention is to extend this method and apparatus to allow a lower communication system to be attached to an upper communication system during this process, as well as attaching a pressure sensor.
[0061] The coiled tubing apparatus and systems described so far do not include the zonal isolation of prior art systems illustrated for example in FIG. 2 (drill-stem testing) and FIG. 3 (wire-line testing). When there are multiple flowing intervals, it is difficult to separate the contributions from each zone without some kind of zonal isolation. Moreover, the pumped nitrogen can itself affect the data being measured on the production logging tool, e.g., if there is a thief zone below the production logging tool, then it is conceivable the pumped nitrogen could go there instead of uphole to the surface.
[0062] For this reason, methods, apparatus, and systems of the invention may comprise zonal isolation tools including cup or non-inflatable packers for monobore operations, and inflatable packers for through-tubing operations. A pair of such packers may be positioned across a reservoir zone of interest and transmit fluid up the coiled tubing to an intermediate diverting section. As used herein “intermediate” means anywhere that is convenient between the base of the coiled tubing and the surface.
[0063] FIG. 8 provides zonal isolation. One primary advantage of this system is the ability to have the test zone flow into the annulus and have the produced fluids managed conventionally at surface. Illustrated in FIG. 8 is a monobore application wherein a coiled tubing 22 is inserted into casing 50 . Coiled tubing 22 includes in the string a top part of a splittable, spoolable connection 102 , a surface-controlled circulation valve or sub 110 (illustrated in circulation mode), a regular, unspoolable check valve 111 , a dual ball valve 112 , and a bottom part of a splittable, spoolable connection 104 . Also illustrated are three production zones 130 , 132 , and 134 , along with respective flows 123 , 122 , and 121 . An optional disconnect 113 may be provided. Illustrated is a surface-controlled downhole shut-in valve 114 , a reversible check valve 115 (which may be hydraulically, electronically, or fiber optically actuated), and a pair of conventional packers 116 and 117 . A flow port 118 may be provided in between packers 116 and 117 , as well as a gauge carrier 119 that may carry one or more sensors therein, and a bull nozzle 120 that may include an optional shear off.
[0064] Use of this method, apparatus and system includes use of a circulation port above the isolation packers. A test as we know it currently would be very difficult due to the communication with the upper zones. This system would depend on the test parameters, such as whether or not the influence of the upper zones would negatively impact the test or not.
[0065] The circulation port 135 would have to inserted above the isolation tools and need not require the development of a spoolable coiled tubing tube-to-tube connector because the entry to the annulus could be a relatively short distance above the bottom-hole assembly, but the interpretation of the testing results will be a lot simpler if the fluid exit to the annulus is far uphole, such as above all of the other reservoir zones.
[0066] Deployment of this system may require a positive isolation of the circulation port 135 during deployment. This can be accomplished through the use of a TIW style ball valve. This system could be used with real time or memory style production logging tools.
[0067] The embodiment of the invention illustrated in FIG. 8 provides the ability to perform a test evaluation on a zone of a reservoir that would allow for the influence of other zones on the test. The embodiment of FIG. 8 also allows selective circulation via a surface-controlled valve to allow fluids to circulate from within the coiled tubing to the coiled tubing annulus.
[0068] For many multilayered reservoirs, it will be necessary to bypass the upper zones and not have their flow contribution enter the surface measurements, as in the embodiment illustrated in FIG. 8 . In such situations, the embodiments of FIGS. 9 and 10 may be useful. These embodiments would provide the necessary zonal isolation and bypass any upper zones to prevent any influence from those zones. The primary advantage of the embodiments of FIGS. 9 and 10 is the ability to have the test zone flow into the annulus at a point above the other contributing zones and still have the produced fluids managed conventionally at surface, eliminating the need to flow produced fluids through the coiled tubing at surface. FIG. 9 illustrates a monobore embodiment with and without gas lift that does not commingle fluid from a zone of interest with fluid from other zones;
[0069] FIG. 10 illustrates a through-tubing embodiment where producing zones 130 , 132 , and 134 are all below tubing 70 and gas lift may be provided from coiled tubing 22 . In some applications of this embodiment, pumping nitrogen down the back-side of the production tubing could also provide the gas lift. In this embodiment, lower two packers 141 and 142 are coiled tubing inflatable packers, while third packer 125 may comprise a conventional tandem packer (mechanically actuated) with a cross flow tool. Optionally, third packer 125 may be an in-casing-set inflatable packer. All other components are as described previously.
[0070] The methods, apparatus and systems of the invention comprise a mid- or intermediate-string isolation apparatus. This apparatus may comprise “cup” style sealing elements. However, this would depend on the test parameters, and whether to inhibit the influence of the upper zones or to provide absolute isolation of a zone of interest.
[0071] An upper isolation system may be inserted mid- or intermediate-string to allow for lengths of up to 3000 ft (0.91 km) from the tested zone to the top of the shallowest influencing zone. A coiled tubing tube-to-tube connector system such as illustrated in FIG. 7 may be used for this purpose.
[0072] Deployment of a mid-string circulation system could be performed either by circulating the well to a kill weight fluid, or by installation of an internal isolation system during deployment of the coiled tubing into or out of the well. The latter method comprises management of the system to avoid coiled tubing collapse, buckling, and differential sticking of the system due to the third packer arrangement.
[0073] Methods, apparatus, and systems of this aspect of the invention comprise a reliable spoolable and splittable connector system and a selective circulation valve to allow fluids to circulate from within the coiled tubing to the coiled tubing annulus. The system functions to isolate the coiled tubing below the circulation valve for deployment and/or removal from the well. A cup-style non-inflatable packer system may be employed to isolate flow in the coiled tubing annulus below the circulation valve, and another valve to function in conjunction with the described system.
[0074] In other embodiments, methods, apparatus and systems of the invention may comprise replacing, when desired, the bottom-most two packers (in monobore applications) with hydraulic packers, so that these may be left in the well for a period of the pressure build-up test, and later either retrieved or moved to the next zone up to be tested.
[0075] Non-limiting examples are now provided for installing systems of the invention that does not commingle fluid from a zone of interest with fluid from other zones.
[0076] An example installation comprises a spliced coiled tubing, wherein the splice is positioned based on the highest difference between the bottom zone and the top zone in a field or area. Once at the wellsite, downhole tools may be installed at the end of the coiled tubing. The installed downhole tools include tools such as: coiled tubing connector; optional disconnect (hydraulicaly or electricaly operated, or operated by other means); surface controlled downhole shut-in valve; reversible check valve (hydraulicaly or electricaly operated, or operated by other means) (this valve could be integrated in the upper packer as well); upper packer (conventional tandem packer for monobore application, inflatable straddle for through tubing application); spacer pipes; one ported sub with optional burst disk for safety; gauge carrier, which may carry one or more downhole pressure and temperature sensors; lower packer (conventional packer for monobore application, inflatable straddle for through tubing application); and nozzle.
[0077] The coiled tubing will then be run in hole (RIH) until the splice section is below the stripper. At this point the coiled tubing injection is stopped, the BOP slip and pipe rams are closed on the coiled tubing pipe and tested, the pressure bled, and the injector head is separated from the coiled tubing BOP. There should be enough risers rigged-up between the injector head and the BOP that is sitting on top of the wellhead.
[0078] Once the riser is disconnected, the coiled tubing is lowered until the splice connection is exposed. The connection is undone, via the a threaded connection, turnbuckle connection, or other like connection built into the splice connector. Tools such as the following may then be connected between the top and bottom halves of the splittable spoolable connector (from top to bottom): surface controlled circulation sub; regular dual flapper check valve; cross-over tool (can also be built-into the top cross-over packer); top cross-over packer (conventional packer if in monobore application or if set inside the tubing string in the through tubing application. Inflatable packer if set in casing in the through tubing application scenario); and dual ball valve.
[0079] The riser connection to the BOP may then be made up, and the BOP slip and pipe rams opened. Then the coiled tubing may be RIH to target depth. Once at the target depth, there may be several processes taking place. All tools may be operated via hydraulics, electrical signals, fiber optic signals or otherwise. The general method is the same, although the specific operation will change slightly depending on the method of operation of the tools.
1) First, pressure up inside the coiled tubing to blow the burst disk in the ported sub. 2) All the packers are then set at the same time. 3) The reversible check valve is open, and the downhole shut-in valve should also be opened at this time. 4) The well is allowed to flow until the rate is constant. 5) The surface controlled shut-in valve is then closed, and the pressure build-up testing begins.
[0085] The surface-controlled downhole shut-in valve and the surface-controlled reversible check valve can both perform the same function, in a way that only one of them is needed for the operation. This is not necessary, though, so the method allows for two separate components to perform these functions independently. The pressure and temperature information is recorded in the downhole gauges.
[0086] Once the testing is finished, if need be, a remedial treatment can take place. For this to happen the shut-in valve has to be open and the downhole circulation sub has to be closed. The treatment fluid is then injected into the formation.
[0087] During the well test phase, there might be a need for pumping nitrogen, so the circulation valve may be opened and nitrogen pumped to lighten the hydrostatic and help the formation in testing to produce.
[0088] Once the first zone is tested, all packers can be unset at once, moved up, and reset and the process can be restarted for the other zones.
[0089] After all the testing in done, the surface controlled reversible check valve is closed, and the coiled tubing pulled out of hole until the split spoolable connector tags the stripper. At this point, the BOP slip and pipe rams are closed, the pressure bled, the riser disconnected.
[0090] All the tools are disconnected. At this point, the reversible check valve is holding the pressure from the well.
[0091] The split spoolable connector is made up together, the riser reconnected, the BOP rams are opened and the coiled tubing is pulled out of hole. The process is repeated until all the tools are out of the hole.
[0092] This process is safe due to the use of the reversible check valve, which again can be either hydraulically operated, electrically operated or fiber optic operated.
[0093] FIG. 11 illustrates schematically a zoned testing apparatus of the invention that removes the requirement for an intermediate diverter section; instead, a downhole sensor apparatus is included together with a communication system that can transmit downhole data in real-time during the testing. Alternatively, one or more downhole sensors and communication components may be integrated into a bottom-hole assembly as illustrated in FIG. 12 , discussed below. The systems as described have a key advantage in that they do not require any communications system within the coiled tubing. The reservoir testing information is performed in these embodiments with surface apparatus as in conventional well testing. The method relies upon the downhole valving apparatus (check valve 112 ) to ensure that only one zone is flowing at a time to that surface apparatus.
[0094] A reliable communication device has been described in reference to FIGS. 6A and 6B herein, which allows the use of the coiled tubing for both flow and reverse flow operations. The device may also be used to activate downhole controls and transmit downhole sensor data. This leads to another embodiment of the invention, wherein the use of the communication system allows elimination of spoolable connectors. Instead, the testing measurements and apparatus are conveyed downhole on the coiled tubing, using sensors similar to those of conventional wireline operations described herein in reference to FIG. 3 . Transmitting downhole power is less of an issue for coiled tubing because hydraulic power is a much more efficient way of moving large amounts of power. This does not mean that hydraulic power needs to be used exclusively for downhole applications on coiled tubing. For example, an apparatus useful in the present invention utilizes a small battery to switch a hydraulic valve. The position of that valve has a large effect on the surface pressure while pumping, so the combination is almost like a transistor: a small amount of power moves the valve but the valve itself controls a large volume of fluid. Similarly, an apparatus useful in the present invention utilizes a battery to move a valve that controls whether or not surface pumped fluid is diverted into an inflatable packer (or a pair of such packers). When the packers are inflated the effect is that the coil to the surface is now in hydraulic communication with a zone of the reservoir and isolated hydraulically from the rest of the reservoir. Large volumes of fluid may then be pumped from the surface into that zone (e.g. to stimulate the rock with acid), or conversely the formation could be allowed to flow into the coil in order to clean out damage or precipitation in the near wellbore. Batteries useful in the invention may include primary cells, secondary (rechargeable) cells, and fuel cells. Some useful primary cell chemistries include lithium thionyl chloride [LiSOCl 2 ], lithium sulfur dioxide [LiSO 2 ], lithium manganese dioxide [LiMnO 2 ], magnesium manganese dioxide [MgMnO 2 ], lithium iron disulfide [LiFeS 2 ], zinc silver oxide [ZnAg 2 O], zinc mercury oxide [ZnHgO], zinc-air, [Zn-air], alkaline manganese dioxide [alkaline-MgO 2 ], heavy-duty zinc carbon [Zn-carbon], and mercad, or cadmium silver oxide [CdAgO] batteries. Suitable rechargeable batteries include nickel-cadmium [Ni—Cd], nickel- metal hydride [Ni-MH], lithium ion batteries, and others.
[0095] FIG. 12 illustrates schematically an apparatus useful in the invention for transmitting flow data to the surface. Reservoir flow from formation 130 is diverted by packers 141 and 142 into an interior pathway within a bottomhole assembly (BHA) 150 , which is connected to coiled tubing 22 via a connector 151 . A venturi or spinner flow meter element 152 is included in the BHA 150 , and flow data transmitted to the surface via a wireless transmitter 154 , which could also operate via electric wire or fiber optic connection.
[0096] FIG. 13 is a schematic logic diagram of a method of the invention for testing one or more producing zones of a wellbore, including the steps of pressuring up inside the coiled tubing to blow a burst disk in a ported sub; setting of all packers at the same time; opening a reversible check valve and a surface-controlled DH shut-in valve; allow a zone of the well to flow until flow rate is constant, and optionally pump in nitrogen for artificial lift; closing the surface-controlled DH shut-in valve; beginning pressure build-up testing; recording pressure and temperature in downhole gauges; determining whether remedial treatment is needed, and if not, repeating the steps for other producing zones.
[0097] In conclusion, methods, apparatus, and systems of the invention provide a downhole valving mechanism which uses a small amount of power downhole to divert fluids in a variety of ways, and wherein the operation of that valve is surface-controlled, either by a fiber-optic line to the surface, or other means, and wherein the fiber-optic line can also be used to pass communication about the status of the valve, and about parameters of the operation (typically pressure and temperature, but could be pH, flow-rate, and the like). The valve may be placed in position above a packer inflation enabling apparatus, with a fiber optic apparatus sending pressure, flowmeter and temperature data to the surface. The straddle packers of the apparatus are then inflated in the usual way, allowing hydraulic communication to and/or from the reservoir. Wellbore fluids are allowed to flow up out of the coiled tubing annulus. A pump may be used to speed this annular fluid flow. The check-valve about the packer inflation device may be activated to allow fluid to flow up from below the valve and into the annulus. This causes a draw-down in pressure across the straddle packer which would cause formation pressure to flow. The formation fluid potentially contains hydrocarbon so it would be risky to allow it to flow to the surface within the coiled tubing, but because of the valve mechanism, instead the hydrocarbon will go through the valve and out into the annulus. At the surface a BOP around the coiled-tubing diverts the annular flow safely into the production facilities, e.g., where it can run through testing equipment to analyze the properties of the hydrocarbon.
[0098] In this example, if there were no perforations in the casing above the straddle packer, then surface flow-meter data could be combined with the downhole pressure data to solve for reservoir properties such as skin, permeability and damage. If there are perforations above the straddle, this would not work, because the flow-meter would also be measuring the contribution of any fluids flowing in, or out, of those perforations. A downhole flow meter solves the problem, and its data may also be transferred to the surface via fiber-optic line, wireline, or wireless transmission. A spinner-type flow meter in the line of flow would lend itself well to a fiber-optic device because as the spinner turns it alternately blocks and releases a beam of light, which provide a data channel to a surface receiver. The faster the beam of light flickers on and off, the faster the spinner was turning, and the higher the measured flow rate.
[0099] Lastly, for wells with very low bottom hole pressure, sometimes even pumping out the annulus at the surface will not allow the wells to flow. In such cases, the valve mechanism could be set up to allow nitrogen or other gas, or mixtures of gases, to be pumped down the coiled tubing. The gas vents out to the annulus. Below, the reservoir fluid would no longer have to displace a hydrostatic column of fluid in the annulus and it would be “lifted” by the down-going gas. This is a natural extension of the embodiment of FIG. 9 to downhole testing.
[0100] For a somewhat more complicated valve apparatus, it is possible to combine the above valving system with the existing packer inflation system. Thus in one position fluid (or gas) from the surface is directed into the wellbore, in another position fluid is directed to inflate the packers, and in a third position there is direct hydraulic communication between the coiled tubing at the surface and the reservoir (e.g. to pump acid). When the valve is diverting surface fluid (gas) to the annulus it may also allow formation fluid via the packers to flow through the annulus. There may be a fourth position that allows flow to pass directly through the tool to any assembly underneath. Surface data to be transmitted may include temperature and pressure, possibly the pressure in each of the ports: coil, annulus, packer, reservoir and below the packer.
[0101] Similarly, if the well had a monobore construction, cup or non-inflatable packers may be used instead of inflatable packers. Or the packer elements could be inflated directly by pumping fluid down the coiled tubing. In both cases zonal isolation would only occur while the pumps were on, but a check-valve apparatus may be installed higher in the coiled tubing string to maintain pressure below it. This may be more successful for the inflatable packer approach because the coil underneath would be a closed system. Because of leakage into the formation, a continuous flow of fluid may be required to keep the cups isolated so non-inflatable (or hydraulic) packers may be employed.
[0102] Bringing the formation fluid into the straddle section raises the important possibility that the zone of the reservoir could be allowed to flow until it had reached steady state equilibrium. The reservoir fluid would pass through an inline flow measurement (spinner or venturi, for example) and this data may be monitored along with downhole pressure to ensure steady-state. At that point the inline flow may be stopped very quickly and the build-up of pressure data monitored. This is a significant improvement over pressure build-up tests done using drill-stem pipe.
[0103] Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art may readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, no clauses are intended to be in the means-plus-function format allowed by 35 U.S.C. § 112, paragraph 6 unless “means for” is explicitly recited together with an associated function. “Means for” clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures.
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A method and apparatus for testing a multi-zone reservoir while reservoir fluids are flowing from within the wellbore. The method and apparatus enables isolation and testing of individual zones without the need to pull production tubing. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It may not be used to interpret or limit the scope or meaning of the claims.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Patent Application No. PCT/CN2011/072943, filed Apr. 18, 2011, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
Embodiments of the present invention relate to communications technologies, and in particular, to a method and device for determining power consumption of a communication site.
BACKGROUND OF THE INVENTION
In a mobile communication network, accompanying with an increase of subscribers and a fast increase of data services, traffic volume of communication grows quickly and mobile network power consumption is in a growing tendency. In order to realize network energy saving and emission reduction, it is necessary to monitor power consumption of a communication site, so as to find a power consumption state of the base station and make an energy saving policy.
A configuration situation of a typical communication site is as follows: A base station in a communication site includes a baseband unit module and a base station carrier module, and further includes a fan, a transmission device, and so on. The communication site is further configured with auxiliary devices such as a communication power supply, a solar energy power supply, a wind energy power supply, an equipment room power supply, and an equipment room air-conditioner. The auxiliary devices are connected to an auxiliary monitoring interface module, where the auxiliary monitoring interface module is configured to report power consumption of the auxiliary devices. The auxiliary monitoring interface module reports the power consumption of the auxiliary device to a power consumption reporting module of the base station. The power consumption reporting module of the base station sends power consumption of the base station and the power consumption of the auxiliary device to an Operating and supporting system (OSS).
However, part of the auxiliary devices of the communication site have a power consumption monitoring capability and part of the auxiliary devices do not have a power consumption reporting capability, therefore, part of the auxiliary devices cannot realize power consumption reporting through the power consumption reporting module. In the same way, the baseband unit module and the base station carrier module in the base station may realize power consumption reporting through the power consumption reporting module, but the transmission device and the fan cannot report power consumption. Therefore, power consumption reported to the OSS by the base station cannot completely reflect power consumption of the communication site.
SUMMARY OF THE INVENTION
Embodiments of the present invention provide a method and device for determining power consumption of a communication site, so as to solve a defect that in the prior art, power consumption of a communication site, which is obtained by an OSS, is not complete.
An embodiment of the present invention provides a method for determining power consumption of a communication site, where the method includes:
receiving power consumption reported by the communication site;
determining power consumption of virtual devices in the communication site according to power of the virtual devices in the communication site and/or traffic volume of the communication site, where the virtual devices include one or more devices which are not capable of monitoring power consumption monitoring and one or more devices which are not capable of reporting power consumption in the communication site; and the traffic volume of the communication site is traffic volume of the communication site at a time point when the power consumption is reported; and
determining power consumption of the communication site according to the power consumption reported by the communication site and the power consumption of the virtual devices in the communication site.
An embodiment of the present invention provides a device for determining power consumption of a communication site, where the method includes:
a power consumption receiving module, configured to receive power consumption reported by the communication site;
a virtual device power consumption calculation module, configured to determine power consumption of virtual devices in the communication site according to power of the virtual devices in the communication site and/or traffic volume of the communication site, where the virtual devices include a device without a power consumption monitoring capability and a device without a power consumption reporting capability in the communication site, and the traffic volume of the communication site is traffic volume of the communication site at a time point when the power consumption is reported; and
a power consumption calculation module, configured to determine power consumption of the communication site according to the power consumption reported by the communication site and the power consumption of the virtual devices in the communication site.
In the embodiments of the present invention, the device without a power consumption monitoring capability and the device without a power consumption reporting capability in the communication site are defined as virtual devices. After receiving the power consumption reported by the communication site, an OSS power consumption platform obtains the traffic volume of the communication site at the time point when the power consumption is reported and determines power consumption of each virtual device respectively according to the traffic volume of the communication site and power of each virtual device. After aggregating the reported power consumption with power consumption of all virtual devices, the OSS power consumption platform obtains total power consumption of the communication site. Therefore, in the embodiments of the present invention, the OSS power consumption platform implements statistics of the total power consumption of the communication site, so that an appropriate energy saving policy may be made for the communication site.
BRIEF DESCRIPTION OF THE DRAWINGS
To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the accompanying drawings required for describing the embodiments or the prior art are introduced briefly in the following. Apparently, the accompanying drawings in the following description are only some embodiments of the present invention, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.
FIG. 1 is a flow chart of a method for determining power consumption of a communication site according to an embodiment of the present invention;
FIG. 2 is a flow chart of another method for determining power consumption of a communication site according to an embodiment of the present invention;
FIG. 3 is an application scenario diagram of another method for determining power consumption of a communication site according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a device for determining power consumption of a communication site according to an embodiment of the present invention; and
FIG. 5 is a schematic structural diagram of a virtual device power consumption calculation module in FIG. 4 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
In order to make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the embodiments in the following description are merely a part rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
FIG. 1 is a flow chart of a method for determining power consumption of a communication site according to an embodiment of the present invention. As shown in FIG. 1 , this embodiment includes:
Step 11 : An OSS power consumption platform receives power consumption reported by a communication site.
The communication site reports power consumption of the communication site to the OSS power consumption platform, and the power consumption reported by the communication site includes power consumption of one or more devices which are capable of monitoring and reporting their power consumption in the communication site.
Step 12 : The OSS power consumption platform determines power consumption of one or more virtual devices in the communication site according to power of the virtual devices and/or traffic volume of the communication site.
In the communication site, some devices is capable of reporting their power consumption, but not capable of monitoring their power consumption. For example, a transmission device and a power amplification device that may report information to a base station in the communication site, they are capable of reporting power consumption but they are not capable of monitoring power consumption. Therefore, power consumption reported to the OSS by the base station does not include power consumption of these devices. Some devices are capable of monitoring power consumption but they are not capable of reporting power consumption. For example, an equipment room power supply in the communication site is capable of displaying its power consumption on a local monitor screen but is not capable of reporting its power consumption to the OSS. In the communication site, some devices are not capable of monitoring power consumption and reporting power consumption, such as a fan and an equipment room air-conditioner. In this embodiment of the present invention, the one or more virtual devices include: one or more devices which are not capable of monitoring power consumption and one or more devices which are not capable of reporting power consumption reporting in the communication site, such as a transmission device, a power amplification device, a fan, an equipment room power supply, and an equipment room air-conditioner, etc.
The traffic volume of the communication site is traffic volume of the communication site at a time point when the power consumption is reported. The traffic volume of the communication site may include at least one of the following: a circuit service volume, temperature, and radio output power of the communication site.
Power consumption of each virtual device may be related to power of the virtual device and the traffic volume of the communication site. The power of a virtual device is power after the virtual device is powered on and before service processing is performed, and is related to configuration and type of the virtual device. For example, a first virtual device is a device with fixed power consumption, such as a transmission device, etc.; and the first virtual device's power consumption is fixed and unchangeable given the same configuration and type. The power consumption of the first virtual device is related to the configuration and type rather than the traffic volume of the communication site. After being configured, no matter whether data being received or sent, the transmission device is in a working state and its power consumption is power consumption in the case of current configuration. If the virtual device is a device with fixed power consumption, the OSS power consumption platform determines power consumption of the virtual device in the communication site according to power of the virtual device in the communication site.
Some virtual devices are devices with changeable power consumption. These virtual devices' power consumption is not just related to the configuration and type, but also related to the traffic volume of the communication site. A second virtual device is a device with a first order linear relationship between its power consumption and the traffic volume of the communication site, such as a power amplification device. The second virtual device's power consumption is related to the traffic volume of the communication site in a first order linear relationship given the same configuration and type. A third virtual device is a device with a second order linear relationship between its power consumption and the traffic volume of the communication site, such as a fan. The third virtual device's power consumption is related to the traffic volume of the communication site in a second order linear relationship given the same configuration and type. Some other devices are fourth virtual devices such as an equipment room power supply. For the fourth virtual devices, in the case that configuration and types are the same, power consumption needs to be obtained by searching a traffic volume and power consumption mapping table. In the communication site, for persons skilled in the art, a device with another relationship between power consumption and the traffic volume of the communication site may also exist, which is not repeated herein.
If the virtual device is a device with changeable power consumption, the OSS power consumption platform determines power consumption of the virtual device in the communication site according to power of the virtual device in the communication site and the traffic volume of the communication site.
After the OSS power consumption platform determines power consumption of each virtual device in the communication site according to the power of the virtual device and the traffic volume of the communication site, total power consumption of all virtual devices may also be calculated. In this embodiment, according to the power consumption of the first virtual devices, the power consumption of the second virtual devices, the power consumption of the third virtual devices, and the power consumption of the fourth virtual devices in the communication site, the OSS power consumption platform obtains power consumption of all virtual devices in the communication site.
Step 13 : The OSS power consumption platform determines power consumption of the communication site according to the reported power consumption and the power consumption of the virtual devices.
In this embodiment of the present invention, the devices without power consumption monitoring capability and the devices without power consumption reporting capability in the communication site are defined as virtual devices. After receiving the power consumption reported by the communication site, the OSS power consumption platform obtains the traffic volume of the communication site at the time point when the power consumption is reported, determines the power consumption of the virtual devices according to the traffic volume of the communication site and the power of the virtual devices, and obtains the power consumption of the communication site according to the reported power consumption and the power consumption of the virtual devices. Therefore, in this embodiment of the present invention, the OSS power consumption platform implements statistics of the power consumption of the communication site, so that an appropriate energy saving policy may be made for the communication site.
FIG. 2 is a flow chart of another method for determining power consumption of a communication site according to an embodiment of the present invention; and FIG. 3 is an application scenario diagram of another method for determining power consumption of a communication site according to an embodiment of the present invention.
As shown in FIG. 2 , this embodiment includes:
Step 21 : An OSS power consumption platform receives power consumption reported by a communication site.
A base station in the communication site reports power consumption of the communication site and traffic volume of the communication site to the OSS power consumption platform through a management channel of a base station controller. The power consumption reported by the communication site includes: power consumption of devices which are capable of monitoring power consumption and reporting power consumption in the communication site. In addition, the base station may also periodically report the traffic volume of the communication site together with the power consumption of the communication site to the OSS. After receiving the traffic volume reported by the communication site, the OSS platform stores the traffic volume for query and analysis.
In the communication site, some devices are not capable of monitoring power consumption, some devices are capable of monitoring power consumption but not capable of reporting power consumption, or some devices are not capable of reporting power consumption and monitoring power consumption. In FIG. 3 , virtual devices include: a transmission device, a power amplification device, a fan, an equipment room power supply, an equipment room air-conditioner, and so on. In FIG. 3 , devices which are capable of reporting power consumption and monitoring power consumption include: a baseband unit module (BBU), a base station carrier module (TRU), a communication power supply, a solar energy power supply, a wind energy power supply, and so on. The communication power supply, the solar energy power supply, and the wind energy power supply may report monitored power consumption to the base station, and the base station reports the monitored power consumption to the OSS power consumption platform.
In this embodiment, power consumption of the virtual devices in the communication site is determined through the following steps.
Step 22 : The OSS power consumption platform determines power consumption of the virtual devices in the communication site according to power of the virtual devices and/or traffic volume of the communication site.
The traffic volume of the communication site is traffic volume of the communication site at a time point when the power consumption is reported.
In this embodiment, the OSS power consumption platform includes a device list of the communication site. In order to make statistics on power consumption of each virtual device, the OSS power consumption platform, according to a feature of each device, defines devices which are not capable of reporting power consumption and devices which are not capable of monitoring power consumption in the device list as virtual devices. By analyzing power consumption of the virtual devices and the traffic volume of the communication site, in this embodiment, the virtual devices are classified into four main categories and a corresponding relationship between power consumption of a virtual device and the traffic volume is established for each virtual device.
Specifically, a virtual device power consumption function table, as shown in Table 1, may be established, where P0 is power of a virtual device in the case of certain configuration and a certain type. In Table 1, a virtual device category may correspond to multiple virtual devices; and virtual devices belonging to the same category have the same corresponding relationship between their power consumption and the traffic volume. In this embodiment, one or more first virtual devices are devices with fixed power consumption. The power consumption of the one or more first virtual devices is fixed and unchangeable given the same configuration and type. A second virtual device, a third virtual device, and a fourth virtual device are devices with changeable power consumption. Their power consumption is not just related to their configurations and types, but also related to traffic volume of a communication site given the same configurations and types. Specifically, a first order linear relationship P=P0+k1*ta is set between power consumption of the second virtual device, such as a power amplification device, and the traffic volume of the communication site. A second order linear relationship P=P0+k1×ta+k2×ta 2 is set between power consumption of the third virtual device, such as a fan, and the traffic volume of the communication site. Some other devices are set as fourth virtual devices, such as an equipment room power supply. For the fourth virtual devices, in the case that configuration and types are the same, power consumption needs to be obtained by searching a traffic volume and power consumption mapping table. In the communication site, for persons skilled in the art, a device with another relationship between power consumption and the traffic volume of the communication site may also exist, which is not repeated herein.
TABLE 1
Virtual device power consumption function table
Virtual Device
Category
Virtual Device
Power Consumption Function
First virtual device
Transmission
P = P0
device, . . .
Second virtual device
Power
P = P0 + k1 × ta
amplification
device, . . .
Third virtual device
Fan, . . .
P = P0 + k1 × ta + k2 × ta 2
Fourth virtual device
Equipment room
Search the traffic volume
power supply . . .
and power consumption
mapping table
In this embodiment, a relationship between the traffic volume and the power consumption of the fourth virtual device (such as an equipment room power supply or an equipment room air-conditioner) may be obtained through practical measurement and analysis, as shown in Table 2.
TABLE 2
Traffic volume and power consumption mapping table
Traffic volume
Power Consumption
ta 1
p1
ta 2
p2
ta 3
P3
. . .
. . .
ta n
Pn
For each virtual device in the device list of the communication site, the OSS power consumption platform determines power consumption of a virtual device according to power of the virtual device and/or the traffic volume of the communication site and with reference to a virtual device category to which each virtual device belongs. In this embodiment, if the virtual device is a first virtual device with fixed power consumption, the OSS power consumption platform determines power consumption of the virtual device in the communication site according to power of the virtual device in the communication site. If the virtual device is a device with changeable power consumption, the OSS power consumption platform determines power consumption of the virtual device in the communication site according to power of the virtual device in the communication site and the traffic volume of the communication site. Specifically, the OSS power consumption platform determines power consumption of the second virtual device in the communication site according to a first order linear relationship between power consumption of the second virtual device and the traffic volume of the communication site. The OSS power consumption platform determines the power consumption of the third virtual device in the communication site according to a second order linear relationship between power consumption of the third virtual device and the traffic volume of the communication site. The OSS power consumption platform determines power consumption of the fourth virtual device in the communication site according to the traffic volume and power consumption mapping table.
Step 23 : The OSS power consumption platform obtains total power consumption of all virtual devices according to power consumption of each virtual device.
In this embodiment, the OSS power consumption platform may obtain power consumption of all virtual devices in the communication site after aggregating the power consumption of the first virtual devices, the power consumption of the second virtual devices, the power consumption of the third virtual devices, and the power consumption of the fourth virtual devices in the communication site.
Step 24 : The OSS power consumption platform calculates power consumption of the communication site according to the power consumption reported by the communication site and the total power consumption of all virtual devices.
After receiving the power consumption reported by the communication site, the OSS power consumption platform obtains the traffic volume of the communication site at the time point when the power consumption is reported, and determines power consumption of each virtual device in the device list of the communication site according to the power of the virtual device and/or the traffic volume of the communication site and with reference to the virtual device category to which each virtual device belongs. The OSS power consumption platform obtains the power consumption of the communication site according to the reported power consumption and the power consumption of all virtual devices. Therefore, in this embodiment of the present invention, the OSS power consumption platform implements statistics of the power consumption of the communication site, so that an appropriate energy saving policy may be made for the communication site.
FIG. 4 is a schematic structural diagram of a device for determining power consumption of a communication site according to an embodiment of the present invention. As shown in FIG. 4 , this embodiment includes: a power consumption receiving module 41 , a virtual device power consumption calculation module 42 , and a power consumption calculation module 43 .
The power consumption receiving module 41 is configured to receive power consumption reported by a communication site.
The power consumption reported by the communication site is power consumption of a device with both a power consumption monitoring capability and a power consumption reporting capability.
The virtual device power consumption calculation module 42 is configured to determine power consumption of virtual devices in the communication site according to power of the virtual devices and/or traffic volume of the communication site.
The virtual devices include: a device without a power consumption monitoring capability and a device without a power consumption reporting capability in the communication site, such as a transmission device, a power amplification device, a fan, an equipment room power supply, and an equipment room power supply.
The traffic volume of the communication site is traffic volume of the communication site at a time point when the power consumption is reported. Power consumption of each virtual device may be related to power of the virtual device and/or the traffic volume of the communication site. In this embodiment, it is set that a first virtual device is a device with fixed power consumption, and a second virtual device, a third virtual device, and a fourth virtual device are devices with changeable power consumption. In the case that configuration and types are the same, a first order linear relationship P=P0+k1*ta is set between power consumption of the second virtual device and the traffic volume of the communication site, such as a power amplification device. A second order linear relationship P=P0+k1×ta+k2×ta 2 is set between power consumption of the third virtual device and the traffic volume of the communication site, such as a fan. Some other devices are set as fourth virtual devices such as an equipment room power supply. For the fourth virtual devices, in the case that configuration and types are the same, power consumption needs to be obtained by searching a traffic volume and power consumption mapping table. In the communication site, for persons skilled in the art, a device with another relationship between power consumption and the traffic volume of the communication site may also exist, which is not repeated herein.
The power consumption calculation module 43 is configured to determine power consumption of the communication site according to the power consumption received by the power consumption receiving module 41 and the power consumption of the virtual devices in the communication site, where the power consumption of the virtual devices in the communication site is determined by the virtual device power consumption calculation module 42 .
In this embodiment of the present invention, the device without a power consumption monitoring capability and the device without a power consumption reporting capability in the communication site are defined as virtual devices. After the power consumption receiving module 41 receives the power consumption reported by the communication site, the virtual device power consumption calculation module 42 obtains the traffic volume of the communication site at the time point when the power consumption is reported, and determines power consumption of each virtual device according to the traffic volume of the communication site and power of each virtual device. The power consumption calculation module 43 obtains the power consumption of the communication site according to the reported power consumption and the power consumption of the virtual devices. Therefore, in this embodiment of the present invention, the OSS power consumption platform implements statistics of the power consumption of the communication site, so that an appropriate energy saving policy may be made for the communication site.
FIG. 5 is a schematic structural diagram of a virtual device power consumption calculation module in FIG. 4 . As shown in FIG. 5 , a virtual device power consumption calculation module 42 includes: a first calculation unit 421 , a second calculation unit 422 , a third calculation unit 423 , a fourth calculation unit 424 , and a fifth calculation unit 425 .
The first calculation unit 421 is configured to determine power consumption of a first virtual device according to power of the first virtual device, where the first virtual device is a device with fixed power consumption in a communication site.
The second calculation unit 422 is configured to determine power consumption of a second virtual device according to power of the second virtual device and traffic volume of the communication site, where there is a first order linear relationship between the power consumption of the second virtual device and the traffic volume of the communication site.
The third calculation unit 423 is configured to determine power consumption of a third virtual device according to power of the third virtual device and the traffic volume of the communication site, where there is a second order linear relationship between the power consumption of the third virtual device and the traffic volume of the communication site.
The fourth calculation unit 424 is configured to determine, according to the traffic volume of the communication site, power consumption of a fourth virtual device by searching a traffic volume and power consumption mapping table.
The fifth calculation unit 425 is configured to obtain power consumption of all virtual devices in the communication site according to the power consumption of the first virtual device, the power consumption of the second virtual device, the power consumption of the third virtual device, and the power consumption of the fourth virtual device.
In this embodiment of the present invention, each unit determines power consumption of each virtual device in a device list of the communication site according to the power of the virtual device and the traffic volume of the communication site. According to the reported power consumption and the power consumption of all virtual devices, power consumption of the communication site is obtained. Therefore, in this embodiment of the present invention, statistics of the power consumption of the communication site is implemented, so that an appropriate energy saving policy may be made for the communication site.
Those of ordinary skill in the art may understand that all or a part of the steps of the foregoing method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program runs, the steps of the foregoing method embodiments are performed. The storage medium may include any medium that is capable of storing program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.
Finally, it should be noted that the foregoing embodiments are merely used for describing the technical solutions of the present invention, but are not intended to limit the present invention. It should be understood by persons of ordinary skill in the art that although the present invention has been described in detail with reference to the foregoing embodiments, modifications may still be made to the technical solutions described in the foregoing embodiments, or equivalent replacements may be made to some technical features in the technical solutions; however, these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions in the embodiments of the present invention.
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In a mobile communication network, technologies are provided for determining power consumption of a communication site. An OSS system receives power consumption information of one or more devices and traffic volume information from a communication site. Then, the OSS determines power consumption of one or more virtue devices of the communication site, which are listed on a pre-configured device list according to power of the virtue devices, traffic volume information of the communication site, or both, wherein the a virtue device is not capable of monitoring power consumption, reporting power consumption, or both. Then the OSS determines power consumption of the communication site according to the power consumption information of the one or more devices received from the communication site and the power consumption of the virtual device in the communication site.
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RELATED APPLICATIONS
This is a continuation of copending U.S. patent application Ser. No. 08/481,740, filed Jun. 7, 1995, now U.S. Pat. No. 5,794,830, which is a divisional of copending U.S. patent application Ser. No. 08/296,127, filed Aug. 25, 1994, now U.S. Pat. No. 5,538,171, which is a division of copending U.S. patent application Ser. No. 07/848,039, filed Mar. 9, 1992, now U.S. Pat. No. 5,344,057, which is a division of copending U.S. patent application Ser. No. 07/560,127, filed Jul. 31, 1990, now U.S. Pat. No. 5,193,727.
FIELD OF THE INVENTION
This invention relates to a unique system and method for performing a post-production operation upon a web subsequent to its output from an image transfer device.
BACKGROUND OF THE INVENTION
It is often desirable in a printing process involving a continuous stream of images laid down upon a moving paper web to incorporate other post-production processes to the web downstream of the printing process. These post-production processes may include, for example, page or job separation, hole punching, color logo application or folding operations. The problem with performing such post-production processes or operations is that the web transferred between the image and the post-production machines may not contain standard length pages or may otherwise have pages in locations upon the web that are difficult to gauge. Thus, the post-processing device must have some means for accurately locating each page presented to it, and furthermore, once each page location is found, must have a means of distinguishing between each individual page sent to it to determine which page must include a given post-production operation.
An additional problem with keeping track of processed pages as they are transferred to a post-production device is that the two devices may run at unsynchronized speeds, especially where they are discrete and separate units. As such, slack may develop in the transfer loop of web between the two devices, resulting in more images en route than expected and potential misapplication of the post-production operation.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a unique system and method for allowing post-production operations to be performed on a moving web containing images wherein the image production element and the post-production device may not be synchronized in their feeding of the web.
It is another object of this invention to provide a system and method for incorporating post-production operations that accurately locates the point upon the web at which the post-production operation is to be applied.
It is another object of this invention to provide a system and method for incorporating post production operations that allows the tracking of various locations upon a moving web to accurately perform a multiplicity of types of post-production operations at these various locations.
It is yet another object of this invention to provide a system and method for incorporating post-production operations that allows the tracking of pages and images placed upon a moving web wherein the pages and images are of variable length.
This invention provides a system for incorporation, in the production of continuous stream of images by an image transfer device upon a moving web, post-production operations upon the web at various web locations. There are means for tracking locations of a web, having a plurality of images placed thereon, output from an image transfer device. There are post-production means to perform a specific operation at locations of the web upon its passing through the post-production means. There are also means for directing the web from the image transfer device to the post-production means. There are means, responsive to the means for tracking, for determining when the location has entered the post-production means, and there are also means responsive to these determining means for commanding the post-production means to perform its specific operation at the location.
In a preferred embodiment, the means for tracking also includes means for generating a pulse each time a interval of web is output from the image transfer device. This means for generating may include means for combining a plurality of pulses to indicate the output from the image transfer device of a page length of web. The post-production means may include means for creating an electronic mark each time one of the intervals of the web passes through the post-production means. This means for creating may include page identification means that indicates, by means of counting the electronic marks, the passing of the page length or certain image of the web through the post-production means.
The determining means may further include counter means that increments a stored value for each page indicated by the means for combining, and decrements the stored value for each page indicated by the page identification means. This stored value is a total length value equaling the number of page lengths upon the web disposed between the image transfer device and the post-production means when the web is pulled taut with relatively no slack thereon. The determining means may further include a register means, responsive to the counter means, to store first through last data blocks equal in number to at least a current value contained in the counter means. Each of the data blocks directly corresponds to a page length disposed between the image transfer device and the post-production means and each of the data blocks contains a data value representative of a post-production operation to be performed upon the web at the page length. The last of the data blocks contains a data value corresponding to the page length increment currently entering the post-production means. The register means may include a shifting means that adds a new data value, deletes a data value, or moves values in data blocks to correspond directly to the movement of each page length increment upon the web from the image transfer device to the post-production means.
In an alternative embodiment, the determining means may including storage register means having a number of storage locations to each store a data value corresponding to the number of intervals between each of the locations upon which the specific post-production operation is to be performed. This storage register means may also include means for monitoring the total number of intervals of the web currently disposed between the image transfer device and the post-production means.
In yet another embodiment, a storage register means may also have a number of storage locations to consecutively store first through last data values corresponding to the number of page length increments between each of the locations upon which a specific post-production operation is to be performed. This storage register may also include a means for structuring a number of storage locations; equal to the maximum number of page lengths upon the web that may be disposed between the image transfer device and the post-production means. This storage register may further include a means for comparing a last data value stored in the storage register to the number of pages successively indicated by the page identification means. This allows the means for comparing to indicate when a correct location has entered the post-production means. There may be a means for moving data values, in response to the comparing means, within the storage register means to add a new data value to the storage register and to delete last data values from the storage register. This means for structuring may include a means for calculating the number of page lengths on the web currently disposed between the image transfer device and the post-production means.
The post-production means may generally include, among other devices, a folder, job separator, printing device, hole punching device, or web cutting device. Additionally, the image transfer device may include among its elements an electronic printer such as a laser, impact or other type capable of the production of variable page length images.
A method for incorporating, in the production of a continuous stream of images by an image transfer device upon a moving continuous web, post-production operations upon the web at various locations is also provided. Such a method would generally include the steps of tracking the locations of a web, having a plurality of images placed thereon, output from the image transfer device. There would also be provided a step of performing, with a post-production means, a specific operation at each of the locations on the web upon its passing through the post-production means. In another step, the web is then directed from the image transfer device to the post-production means. In response to the tracking step, the time when a correct location has entered the post-production means is then determined. The method further includes the step of commanding the post-production means, in response to the determination of the point when the correct location has entered the post-production means, to perform its specific operation at the correct location.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects and advantages of the present invention will be more clearly understood in connection with the accompanying drawings in which:
FIG. 1 is a schematic diagram of a system for incorporating post-production operations to a printed web according to this invention;
FIG. 2 is a block diagram showing the calculation of the number of pages in the intermediate loop for the post-production page pass through determination system of FIG. 1;
FIG. 3 is a sequence of three sequential diagrams of a shifting operation for the shift register used in the post-production page pass through determination system of FIG. 1;
FIG. 4 is a block diagram of the shifting control process for the shift register of FIG. 3;
FIG. 5 is a sequence of three sequential diagrams of an alternative incremental distance storage register system for use with the post-production page pass through determination system of FIG. 1.;
FIG. 6 is a sequence of three sequential diagrams of an alternative absolute distance storage register for use with the post-production page pass through determination system of FIG. 1;
FIG. 7 is a schematic diagram of the electronic interval detector in the image transfer device of FIG. 1; and
FIG. 8 is a schematic diagram of the electronic interval detector of the post-production device of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A system for incorporating a post-production operation to a printed web is depicted in FIG. 1 . The system consists of a source of web 20 that is, for example, a paper material upon which printing is to be transferred. The web is thus fed to an image transfer device 40 that performs the printing process. A loop of web material 74 exits the image transfer device and enters a desired post-production device 48 . This post-production device 48 performs an operation upon the web at various locations. This specific operation may be, for example, one of folding, cutting, application of further printing or hole punching. The length of web, when disposed tautly between the image transfer device and the post-production device, is known as the taut distance 50 . This taut distance can be characterized in terms of predetermined intervals 72 of length as small as ⅛″, or in terms of a given number of page lengths 70 . Each page length generally corresponds to a given number of intervals 72 .
The image transfer device 40 contains an image transfer element 180 and contains a distance measurement device 200 , as shown in FIG. 7, that measures the intervals 72 of length passing out of the image transfer device. These intervals of length are converted into corresponding electronic pulses or marks that are transmitted to a mark combiner 42 .
This mark combiner translates the marks into a quantifiable increment, generally the length of a, page, and outputs data 54 indicating a page each time enough marks are combined to designate a page length of web passing through the image transfer device 40 . The system quantifies measurements to page size to lessen the effects of rounding and truncation errors potentially resulting from discrete interval measurements.
After the web is fed from the image transfer device, it is carried over an intermediate loop 74 before again traveling into and out of the post-production device 48 . Thus, a means for hand-shaking the operation of the image transfer device and the post-production device must be utilized if a page from the image transfer device is to be accurately processed by the post-production device. This hand-shake means is the system symbolized by the post-production pass through determination block 44 in FIG. 1 . This determination system 44 is fed data 52 indicating which page should contain a post-production operation. The data 52 may be synchronized with data 53 controlling the image transfer device 40 . When a page passes through the image transfer device 40 and a simultaneous signal for post-production 52 is sent to the determination system 44 , the system 44 internally flags that page for a post-production operation.
The post-production device also reads pages passing through itself, as shown by the distance measuring element 220 in FIG. 8 . The determination system 44 has the taut distance 50 programmed into it, so it determines how many pages must pass through the post-production device 48 for the flagged page from the image transfer device to reach the post-production device. It then counts off pages passing through the post-production device, using the post-production output indicator signal 56 , to determine when the flagged page is present at the post-production device. At this point, the determination device transfers a post-production command 76 to the post-production device 48 to instruct the post-production device operational element 194 , as shown in FIG. 8 to perform its operation.
As illustrated, one important variable that must be known for the determination system 44 to accurately command an operation is the number of pages in the intermediate loop 74 . If the image transfer device 40 and the post-production device 48 are initiated with a loop that is relatively taut and with both running at synchronized rates of web transfer, then the number of page lengths in the loop remain equal to the taut distance 50 . However, it is sometimes the case, especially where independent and removable post-production units are utilized, that the two devices will run at slightly offset speeds. To account for this, FIG. 2 depicts a counter unit 82 that receives the taut distance value 80 and continually increments 88 or decrements 90 this initial value 80 based, respectively, upon each time a page is output by the image transfer device 84 or passed through the post-production device 86 . In this way, an ongoing real-time calculation of total pages in the loop 92 is achieved.
Using this loop page number figure, the determination system 44 accurately gauges when a page arrives at the post-production device.
The actual storage of post-production signals for pages disposed in the intermediate loop is depicted in three time frames in FIG. 3 . The storage means consists of a shift register shown in a relative starting time frame 94 . The shift register contains a number of shift locations equal to the number of pages in the loop 100 . In the starting state 115 , this number of pages 100 should equal the taut distance. In a simple embodiment, where one post-production device is utilized, each page in order of its appearance in the left-to-right loop from the image transfer device to the post-production device contains a number equal to either zero or one. Zero may represent no operation by the post-production device for that page location, while one represents that a post-production operation is to be performed.
The register 96 depicts the second time frame for the shift register in which a new page 116 has been added to the loop from the image transfer device. This new page holds a zero value, meaning no post-production operation is to be performed to it. At the same time, the post-production device has relatively synchronously transferred out a completed page. This page is shown in the previous time frame register having a one value 108 at the register end position. The determination system has read the last end value and commanded the post-production device to operate upon the page. The new end value 110 of the register 96 of the second time frame contains a zero value and, thus, shall have no post-production operation performed to it. All other zeros and ones in the register have been shifted one space. This process continues indefinitely, until all web images have been processed.
In the final time frame 98 of FIG. 3, another new page 104 has been added to the front of the register having a zero, non-post-production, value. However, the post-production device has not yet received and processed the last page designated by a zero in the end register 110 . Thus, a slack 102 has developed in the loop. The counter means depicted in FIG. 2 will, therefore, be incremented without a nearly simultaneous decrement due to a page leaving the post-production device. The shift register then gains a value holding the new page instruction at the front of the register 106 . When the post-production device again passes through a sheet, decrementing the counter, the shift register will disable the front location as the simultaneous shifting of all values in the register occurs.
A general flow chart depicting this block adding operation of the shift register of FIG. 3 is shown in FIG. 4 . The current number of pages in the loop 142 is input to a decision block 144 in response to the output of an image page by the image transfer unit 140 . If the number of pages has increased 146 , then a block is added to the shift register for storage of the new page data 150 and no shift occurs. Similarly, if the number of pages has not changed 148 , then all blocks will be shifted down, and the new image page data, when ready, is added to the first block 152 .
The above embodiment generally involves the storage of a piece of data corresponding to each page in the intermediate loop 74 between the image transfer device 40 and the post-production device 48 . As each page is shifted down the loop, the data of the shift register means is also shifted with new page data added at the front and old page data read for commands and dropped off at the rear of the register, just as the pages in the loop themselves enter and leave. An alternative means for storage of data corresponding to pages in the loop is depicted in FIG. 5 . This means stores the number of pages disposed between the post-production pages rather than a single data value for each page. The last storage block 162 in the register 160 at the exemplified starting state depicts nine pages until the next post-production page will appear at the post-production means. Once nine pages have moved through the post-production unit, the operation will then be performed to that ninth page. All the storage blocks will then be shifted, as shown by the second register 170 , such that the second-to-last block 164 in the starting register 160 is now the new last end block upon which the determining system 44 bases its count of identified pages 56 from the post-production unit for the next post-production operation 168 . In this exemplified register 170 , the number of pages until the next post-production operation is seven.
At a point in time when a new post-production page enters the loop, based upon signals 52 and 53 shown in FIG. 1, the next incremental page distance value 174 is placed at the front of the storage register. Generally, this system requires fewer storage blocks than the shift register system of the embodiment of FIG. 3 . However, it is possible that, if a post-production operation must be performed it each page within the loop, as many storage locations are required as for the shift register system of FIG. 3 . The creation of additional storage blocks may be accomplished in this type of system with a counter that detects pages in the loop.
An advantage of the second storage embodiment is more clearly prevalent in FIG. 6 . Here, absolute distance consisting of the number of pulses between post-production operations is stored rather than numbers of pages. This system depicts a storage register 210 at a starting time and then at a time 212 after 30 pulses have been counted off by the post-production device wherein a shift 214 has occurred and a new distance of 14 pulses has been added to the front of the register 216 . An advantage of using pulses directly from the distance measuring devices 200 of FIG. 7 and 220 of FIG. 8 is that post-production operations can be more accurately pinpointed to specific variable locations upon each page as designated by a specified number of pulses, rather than simply at the page. Furthermore, since post-production operations are located relative to an absolute distance measurement rather than an arbitrary preprogrammed page measurement, pages of varying length may be easily included in the same web. Note that FIG. 8 includes a pair of drive rollers 224 that rotate (arrows 226 ) to drive the web 74 through the post-production device 48 .
In any of the above embodiments, several post-production devices may be included and a multiplicity of types signals may be shifted by the storage means in order to perform one or more selectable types of post-production operations. These different operations may each be performed upon the same or upon differing pages within the web.
It should be understood that the preceding is merely a detailed description of a preferred embodiment. It will be obvious to those skilled in the art that various modifications can be made without departing from the spirit or scope of the invention. The preceding description is meant to describe only a preferred embodiment and not to limit the scope of the invention.
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A system and method for incorporating, in the production of a continuous stream of images, by an image transfer device upon a moving web, post-production operations upon the web at various locations. Locations of a web, having a plurality of images placed thereon, output from an image transfer device are tracked. Specific operations at various locations upon the web are performed by a post-production device as the web passes through it. The web is directed from the image transfer device to the post-production device. In response to the tracking of locations upon the web, the point when a location has entered the post-production device is determined. In response to this determination, the post-production device is commanded to perform its specific operation at a connect location.
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BACKGROUND
[0001] The invention relates to a rotating passage feed system for connecting, on one side, pressure means conduits arranged in a shaft and, on the other side, pressure means connections, which are rotating relative to each other, through which a liquid pressure means is guided. The rotating passage includes a shaft; at least one pressure means conduit in the form of a channel extending axially within the shaft; a radial bore hole for each pressure means conduit from the surface of the shaft to the pressure means conduit, wherein the bore holes of the different pressure means conduits are offset relative to each other in the axial direction; a connecting part, which surrounds the shaft in a region of the bore holes, wherein the connecting part is provided in the region of each bore hole with a ring groove, which completely covers the bore hole, so that a ring channel is produced with the shaft; a pressure means connection for each pressure means conduit, which is connected in a pressure-tight manner to each of the ring channels and supplies these channels with pressure means; and seal rings, which seal the ring channels from each other.
[0002] Rotating passage feeds for connecting pressure means conduits in machine parts rotating relative to each other about a rotational axis are known, wherein the pressure means conduits of the different machine parts are connected to each other via tapped bore holes and ring grooves. From DE 41 22 926 A1, a rotating passage feed is known, which connects pressure means conduits in the form of several axial channels within a rotating first shaft by means of an upright housing with pressure means conduits of a second rotating shaft. The pressure means conduits of the first shaft connect via radial bore holes to ring channels in the surface of the shaft, which are formed by ring grooves. Going out from the ring channels, additional pressure means conduits are attached in the housing. The pressure means can now flow into the ring channel via the axial pressure means lines of the first rotating shaft by means of the radial bore holes and from there into the pressure means conduit of the upright machine part. A disadvantage in this construction is the ring grooves, which are to be machined with high work expense both into the shafts and also into the housing part.
[0003] Another rotating passage feed is known from DE 42 03 964 C1. Here, pressure means conduits of a stator connect to the pressure means conduits of a rotor via ring channels and tapped bore holes. To prevent leakage between the ring channels, which are offset axially relative to each other, sealing rings are attached between the ring channels, whereby a sealing connection between the stator and rotor is produced. Due to the use of the sealing rings, the assembly of the shaft with recessed regions is made considerably more difficult. Furthermore, radial or conical transitions are provided at the transition between the recesses and the shaft, in order to enable assembly. This requires, in turn, expensive finishing work.
SUMMARY
[0004] Therefore, the invention is based on the objective of preventing the noted disadvantages and thus creating a rotating passage feed for pressure means, which can be produced inexpensively and with lightweight construction and which is easily assembled.
[0005] According to the invention, this objective is met in that between the connecting part and the shaft, a central sleeve is attached, which is connected to the connecting part in a pressure-tight and non-rotatable manner and which has first cylindrical ring sections, whose outer surface is provided with annular openings spaced regularly in the peripheral direction, wherein the openings are covered completely by the annular grooves of the outer channel, wherein the first cylindrical ring sections are separated from each other by second cylindrical ring sections, which have no openings, in the axial direction; that the radial bore holes are provided as elongated holes and the length is selected so that in each position of the shaft relative to the central sleeve, at least one opening aligns completely with the elongated hole; and that the sealing rings are attached in ring grooves of the shaft and interact with the second cylindrical ring sections of the central sleeve.
[0006] The pressure means are led through the pressure means connections into the ring channels of the connecting piece. From there, the pressure means are guided via the openings of the first ring section and the bore hole configured as an elongated hole into the pressure means conduit of the shaft. In this configuration, a reversal of the pressure means flow is also conceivable.
[0007] Through the insertion of a central sleeve between the shaft and connecting piece, the requirements on the load capacity of the connecting pieces can be decreased considerably. So that the loading of a shaft rotating relative to the connecting piece is carried by the central sleeve, the connecting piece still only has to fulfill the task of providing ring channels, through which the pressure means can be guided from the connecting piece into the pressure means conduits of the shaft. Therefore, in detail it is possible to realize the connecting piece inexpensively and with lightweight construction.
[0008] To prevent or to minimize leakage of the pressure means in the axial direction between the shaft and the connecting piece, steel sealing rings are provided between these two components. These are positioned in annular recesses in the shaft. For assembly, the shaft is pushed into the connecting part, with the steel sealing rings being flattened in the radial direction. If the steel sealing rings fit in a ring groove of the connecting part, these rings snap into place. In order to enable assembly, the side walls of the ring grooves of the connecting piece must be provided with transitions in the form of a radius, a hyperbola, a parabola, a cone, or the like. This makes complicated and expensive finishing work on the connecting part necessary. In the configuration of a rotating passage feed according to the invention, the steel sealing rings are attached in ring-shaped recesses in the shaft. The central sleeve is positioned, such that the first cylindrical ring sections border the ring grooves radially inwards. The seal closure between the shaft and connecting part is created by the interaction of the sealing rings lying in the recesses with the inner surface of the central sleeve. When the shaft is inserted into the central sleeve, the sealing rings are pressed together. When the shaft with the sealing rings arranged thereon is shifted further in the axial direction, the sealing rings are now guided not to the ring grooves in the direction of the axial end position, but instead to the first cylindrical ring sections with ring-shaped openings, which prevents the steel sealing rings from snapping into place. Therefore, the complicated finishing work on the side surfaces of the ring grooves can be eliminated.
[0009] Through the ring-shaped, uniformly spaced openings in the first cylindrical ring sections, a constant contact between the radial bore holes configured as elongated holes in the shaft and the associated ring channels is produced and thus a continuous flow of pressure means during the operation is guaranteed.
[0010] In an advantageous configuration of the invention, the connecting part includes of one or more sleeves, which are produced from sheet metal parts through a shaping process. Through the use of sheet metal parts, which are brought into the desired sleeve-shaped form by a shaping process, the connecting part can be produced with lightweight construction. The inexpensive and easy to manage production method represents another advantage.
[0011] In another advantageous configuration of the invention, the central sleeve is produced from a sheet metal part through a shaping process and the openings are stamped out of this part after the shaping. Through the use of a central sleeve produced from a sheet metal part through shaping, the weight of this arrangement can be reduced to a minimum. Furthermore, the production costs are significantly reduced through the use of an easy to handle production process. Another advantage results from the fact that rotating passage feeds can be produced with many different pressure means conduits without complicated adaptation of the production paths.
[0012] In one embodiment also included in the protective scope of this invention, the connecting part is formed of an angle sleeve for each pressure means connection, wherein the wall of the angle sleeve has a U shape in its longitudinal section and thus forms a ring groove. Through this building-block principle, it is possible to produce different rotating passage feeds, which differ through the number of pressure means conduits or pressure means connections, inexpensively without complicated adaptation of the production processes.
[0013] It is also possible to provide the connecting part formed from an outer sleeve and several angle sleeves, wherein the angle sleeves are attached between the first cylindrical sections on the central sleeve, the angle sleeves are covered by the outer sleeve, and the connections between the outer sleeve and the central sleeve, between the outer sleeve and the angle sleeves, and between the angle sleeves and the central sleeve are pressure-tight. In this configuration of the invention, the ring channels, which connect the pressure means connections to the pressure means conduits, are defined in the radial direction by the central sleeve or the outer sleeve. The boundaries in the axial direction are realized by the angle sleeves. Pressure means, which is guided, for example, in an axial pressure means conduit of the shaft, can flow into the ring channel between the central sleeve, outer sleeve, and angle sleeve via the radial bore hole configured as an elongated hole and the openings of the first cylindrical ring section of the central sleeve communicating with the radial bore hole and from there into the pressure means connection. In this configuration of the invention, it is also possible to produce rotating passage feeds with many different pressure means conduits, for a minimum number of different individual parts, through slight changes in the embodiment of the outer sleeve.
[0014] Furthermore, the angle sleeve can be set on the central sleeve by means of a press fit. Therefore, a pressure-tight connection between these two components is produced.
[0015] In another reduction of the invention to practice, the wall of the angle sleeves have a U shape in its longitudinal section, wherein the legs of the U are directed radially away from the central sleeve of the outer sleeve. Here, it is conceivable that the connecting piece of the two legs contacts either the central sleeve or the outer sleeve. Therefore, the stability of this arrangement is increased relative to a one-leg angle sleeve.
[0016] In another embodiment, the angle sleeves are each provided with a sealing ring, whereby a pressure-tight connection between the angle sleeve and the central sleeve or outer sleeve is produced. Here, the ring groove defined by the U-shaped wall of the angle sleeve can be used as a receptacle space for the steel sealing ring.
[0017] In other embodiments of the invention, the connections between the central sleeve and the outer sleeve, the central sleeve and the angle sleeves, and the outer sleeve and the angle sleeves are produced in the form of press-fit connections or in the form of ring-shaped weld connections.
[0018] Advantageously, in the outer surface of the central sleeve there are additional elongated holes in the peripheral direction, which are each covered by an additional ring channel. Through this arrangement, pressure means leakage, which is guided in the axial direction along the shaft, can escape via the elongated holes and can be discharged via a ring channel and a pressure means conduit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Additional features of the invention result from the following description and from the drawings, in which embodiments of the invention are shown in a simplified form. In the drawings:
[0020] FIG. 1 a partial view of a rotating passage feed according to the invention in longitudinal section;
[0021] FIG. 2 a longitudinal section view through the hub part of a rotating passage feed according to the invention;
[0022] FIG. 3 a cross sectional view through a rotating passage feed according to the invention along III-III from FIG. 1 ,
[0023] FIG. 4 a partial cut-out view of the central sleeve in the region of a first cylindrical section in plan view;
[0024] FIG. 5 a longitudinal section view through another embodiment of a hub part of a rotating passage feed according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In FIG. 1 , a partial view of a rotating passage feed 1 according to the invention is shown in longitudinal section. This includes a hub part 2 , a shaft 3 , and a bearing 4 . The hub part 2 and shaft 3 are supported by means of the bearing 4 so that they can rotate relative to each other about a common rotational axis. For the inventive concept, it is not important whether the hub part 1 is stationary and the shaft 2 performs a rotating motion or whether the shaft 1 is stationary and the hub part 2 performs a rotating motion or whether both components perform a rotating motion, wherein the rpm values of the two components can be different.
[0026] The hub part 2 is assembled from a central sleeve 9 and a connecting part 5 , comprising a pressure means connection 6 and a first angle sleeve 7 . The first angle sleeve 7 is attached with a positive-fit on the central sleeve 9 , wherein the wall of the first angle sleeve 7 , which has a U shape in cross section, forms a ring channel 8 , which covers the central sleeve 9 , together with the outer surface 13 of the central sleeve 9 . In order to produce a pressure-tight connection between the pressure means connection 6 and the ring channel 8 , this is connected to one of its ends by a press fit and a weld seam 14 with the outer periphery of the first angle sleeve 7 .
[0027] In FIG. 1 , only one pressure means connection is shown, which is in flow connection with a pressure means conduit. It is easy to see that through multiple duplication of the components, an arbitrary number of pressure means connection can be connected to pressure means conduits.
[0028] The central sleeve 9 is assembled from a hollow cylindrical part 10 and a pot-shaped extension 11 . The pot-shaped extension 11 is used for holding a bearing, whereby the central sleeve 9 can be connected to the shaft 3 so that it can rotate. The cylindrical part 10 is provided with openings 12 , which are completely covered by the first angle sleeve 7 . Therefore, it is guaranteed that the openings 12 are in flow connection with the ring channel 8 . Both the connection between the pressure means connection 6 and the first angle sleeve 7 and also the connection between the central sleeve 9 and the first angle sleeve 7 are pressure-tight. This can be realized through weld connections 14 , 15 or with the help of sealing rings 16 .
[0029] The shaft 3 is provided with pressure means conduits 17 , which are in flow connection with the ring channel 8 via radial bore holes 22 and the opening 12 of the central sleeve 9 .
[0030] In one advantageous configuration of the invention, the central sleeve 9 and/or the first angle sleeve 7 are formed of a sheet metal part, which is brought into the desired form through a shaping process.
[0031] FIG. 2 shows a longitudinal section through a preferred embodiment of the hub part 2 of a rotating passage feed according to the invention. Here, it involves an embodiment, in which two separate pressure means flows can be transmitted. First angle sleeves 7 are shown, which are attached in a pressure-tight manner to a central sleeve 9 , wherein the inner side of the angle sleeves form ring channels 8 , which are in flow connection with pressure means connections 6 , together with the outer surfaces of the central sleeve 9 , wherein each end of the pressure means connections is connected to the outer periphery of an angle sleeve. The hollow cylindrical part 10 of the central sleeve 9 includes first cylindrical ring sections 18 , whose outer surfaces are provided with ring-shaped openings 12 spaced regularly in the peripheral direction. The hollow cylindrical part 10 of the central sleeve 9 is provided with a first cylindrical ring section 18 for each pressure means connection 6 or first angle sleeve 7 , wherein each first cylindrical ring section 18 is covered by a first angle sleeve 7 , so that its openings 12 lie completely within the ring channel 8 .
[0032] In the axial direction, the first cylindrical ring sections are bounded by second cylindrical ring sections 19 without openings.
[0033] Furthermore, the hollow cylindrical part 10 of the central sleeve 9 includes third cylindrical ring sections 20 , in whose outer surfaces elongated holes 21 extending in the peripheral direction are provided. The third cylindrical ring sections 20 are covered by second angle sleeve 7 a , wherein the axial extent of the elongated holes 21 is selected so that these are completely covered by the angle sleeve 7 . The second angle sleeve 7 a forms another ring channel 8 in interaction with the outer surface of the third cylindrical ring section 20 .
[0034] Here, although one embodiment of a rotating passage feed according to the invention is shown with two pressure means connections and two pressure means conduits, the invention is obviously not limited to this special embodiment. As is easy to see for someone skilled in the art, it is naturally possible to connect an arbitrary number of pressure means connections 6 to the pressure means conduits 17 as a function of the length of the central sleeve 9 and the embodiment of the shaft 3 . Furthermore, it is naturally possible to provide the central sleeve 9 with several third cylindrical ring sections 20 .
[0035] FIG. 3 shows a cross section through a rotating passage feed according to the invention from FIG. 1 taken along the line III-III. A pressure means connection 6 and a first angle sleeve 7 , which forms the ring channel 8 in interaction with a first cylindrical ring section 18 of the central sleeve 9 , can be seen clearly. The ring-shaped openings 12 spaced regularly in the peripheral direction in the first cylindrical ring section 18 of the central sleeve 9 can be seen clearly.
[0036] In the illustrated embodiment, the shaft 3 comprises a hollow shaft 23 , which is provided on the inner surface with pressure means conduits 17 in the form of axial recesses. A solid shaft 24 is arranged within the hollow shaft 23 , wherein a pressure-tight connection exists between the outer surface of the solid shaft 24 and the inner surface of the hollow shaft 23 . The outer surface of the solid shaft 24 thus forms the radially inner boundary of the pressure means conduits 17 . Furthermore, the pressure-tight contact between the hollow shaft 23 and the solid shaft 24 prevents pressure means from being able to be exchanged between the various pressure means conduits.
[0037] The connection between the pressure means conduit 17 and the associated ring channel 8 is produced via the openings 12 of the central sleeve 9 and a radial bore hole 22 in the hollow shaft 23 , wherein the radial bore hole 22 is formed as an elongated hole. Each pressure means conduit 17 is provided with a radial bore hole 22 embodied as an elongated hole. Here, the various radial bore holes 22 are offset axially relative to each other, wherein each radial bore hole 22 communicates with the openings 12 of a first cylindrical ring section 18 . In order to minimize leakage between two adjacent first cylindrical ring sections, in the region of the second cylindrical ring sections 19 there are sealing rings 25 between the central sleeve 9 and the hollow shaft 23 ( FIG. 1 ).
[0038] In order to guarantee that a flow of pressure means can take place in each position of the shaft 3 relative to the central sleeve 9 , the radial bore hole 22 is provided such that at least one opening 12 lies completely over the radial bore hole 22 embodied as an elongated hole. This is shown both in FIG. 3 and also in FIG. 4 .
[0039] Although in FIG. 3 a shaft 3 is shown comprising a hollow shaft 23 and a solid shaft 24 , it is understood that the field of application of the rotating passage feed according to the invention is not limited to such configurations. Naturally, it would also be conceivable that the axial recesses, which form the pressure means conduits 17 are formed in the outer surface of the solid shaft. Furthermore, concentric hollow shafts would also be conceivable, between which several pressure means conduits are arranged. In connection with this, pressure means conduits provided as ring channels would also be conceivable. Furthermore, solid shafts with axial bore holes and the like would also be possible.
[0040] With reference to FIGS. 1 and 3 , the function of the rotating passage feed will be explained below. Here, a flow of pressure means from the pressure means connection 6 to the pressure means line 17 is assumed. Naturally, with this arrangement the pressure means can also be led in the reverse direction.
[0041] The pressure means can flow along the path designated with the arrows 26 . Via the pressure means connection 6 , the flow is led into the ring channel 8 . From the ring channel 8 out, the openings 12 of the central sleeve 9 are pressurized. It should be pointed out again that the radial bore hole embodied as an elongated hole always communicates with at least one of the openings 12 . Via the appropriate opening 12 a , the pressure means is now led via the radial bore hole 22 into the pressure means conduit 17 . This applies naturally for each system consisting of pressure means connection 6 , ring channel 8 , opening 12 , radial bore hole 22 , and pressure means conduit 17 independent of the other systems present. Therefore, it is possible to charge different pressure means conduits 17 with different pressures.
[0042] Possibly escaping pressure means leakage, which flows in the axial direction between the shaft 3 and central sleeve 9 , is fed via the elongated holes 21 into ring channels 8 and can be discharged from there either via pressure means conduits 17 into the shaft 3 or a not-shown pressure means connection on the angle sleeve 7 a.
[0043] FIG. 5 shows a longitudinal section through another embodiment of a hub part 2 of a rotating passage feed according to the invention. This includes, in turn, of a central sleeve 9 , with first cylindrical ring sections 18 , whose outer surface is provided with ring-shaped openings 12 spaced regularly in the peripheral direction, second cylindrical sections 19 in the axial direction between first cylindrical ring sections 18 , third cylindrical ring sections 20 , whose outer surface is provided with elongated holes 21 extending in the peripheral direction, and a pot-shaped extension 11 for holding a bearing. The embodiment according to FIG. 5 differs from that of FIG. 1 by the configuration of the connecting part 5 . In the present case, this comprises several third angle sleeves 27 and an outer sleeve 28 .
[0044] In a preferred embodiment, the third angle sleeves 27 and/or the outer sleeve 28 are produced from a sheet metal part through a shaping process.
[0045] The third angle sleeves 27 are fixed on the outer surface of the second cylindrical ring sections 19 in a positive-fit manner and covered by the outer sleeve 28 , wherein a positive-fit connection with the third angle sleeves 27 is provided. In the illustrated embodiment, the wall of the third angle sleeves 27 has a U shape in its longitudinal section, wherein the legs 29 of the U-shaped wall point radially outwards from the central sleeve 9 towards the outer sleeve 28 . A connecting part 30 couples the two legs 29 of a third angle sleeve. Two embodiments are conceivable. First, a radially outwards open U (shown in FIG. 5 ) or a radially inwards open U (not shown). In the first case, the connecting part 30 contacts the central sleeve 9 ; in the second case it contacts the outer sleeve 28 . The pressure-tight connection between the central sleeve 9 and the outer sleeve 28 can be produced via ring-shaped weld connections 31 at the contact points of the two sleeves. To prevent axial leakage of the pressure means, in addition to a positive-fit press connection, ring-shaped weld connections 32 are provided between the connecting part 30 of the third angle sleeves 27 and the outer sleeve 28 and/or the central sleeve 9 . The other connecting point can also be secured against leakage with sealing rings 33 , which are arranged between the legs 29 of the third angle sleeves 27 .
[0046] The function of this embodiment is identical to that described above, with the exception that the ring channels 8 are formed in this case by the central sleeve 9 , the outer sleeve 28 , and the legs 29 of the third angle sleeves 27 .
[0000] LIST OF REFERENCE SYMBOLS
[0000]
1 Rotating passage feed
2 Hub part
3 Shaft
4 Bearing
5 Connecting part
6 Pressure means connection
7 First angle sleeve
7 a Second angle sleeve
8 Ring channel
9 Central sleeve
10 Hollow cylindrical part
11 Pot-shaped extension
12 Opening
13 Outer surface
14 Weld connection
15 Weld connection
16 Sealing ring
17 Pressure means conduit
18 First cylindrical ring section
19 Second cylindrical ring section
20 Third cylindrical ring section
21 Elongated hole
22 Radial bore hole
23 Hollow shaft
24 Solid shaft
25 Sealing ring
26 Pressure means path
27 Third angle sleeve
28 Outer sleeve
29 Leg
30 Connecting part
31 Weld connection
32 Weld connection
33 Sealing ring
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A rotating passage feed system for admitting pressure means into two machine parts (hub part ( 2 ), shaft ( 3 )) which rotate relative to one another about a common axis is provided. Conduits ( 17 ) that convey the pressure means are located in the shaft ( 3 ) and are joined to pressure means connections ( 6 ) via tapped holes while a connecting part ( 5 ) in which ring channels ( 8 ) are provided is also joined thereto. A central sleeve ( 9 ) is joined to the connecting part ( 5 ) in a non-rotatable manner. The connecting part ( 5 ) and the central sleeve ( 9 ) are produced in an inexpensive manner as lightweight structure formed from sheet metal through a shaping process.
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This is a divisional patent application of U.S. Ser. No. 10/424,612 filed 28 Apr. 2003, now U.S. Pat. No. 7,022,664 issued 4 Apr. 2006, which in turn is a continuation of U.S. Ser. No. 09/816,631 filed 23 Mar. 2001, now abandoned.
FIELD OF THE INVENTION
The invention relates to 1,2-substituted 2,3-dihydro-1H-5,9-dioxacyclohepta[f]inden-7-ones and 7-substituted benzo[b][1,4]dioxepin-3-ones and to the use of these compounds in fragrance compositions.
BACKGROUND OF THE INVENTION
With the launch of an unusual marine women's fragrance, a new trend began to be established in perfumery at the beginning of the 1990s, which was continued in numerous similar marine fragrance creations and peaked in very successful feminine perfumes in 1996 and 1997. However, as soon as 1991 a successful marine men's fragrance also appeared on the market and in 1997 a bodycare series having an extremely marine effect. Virtually all of these marine fragrances are based on 7-methylbenzo[b][1,4]dioxepin-3-one (Calon 1951®). This key compound is described in Beereboom, et al. U.S. Pat. No. 3,647,479 (“Beereboom”) together with derivatives which bear methyl, ethyl, propyl and butyl groups in the 7 position. Published patent EP 0 902 024 A1 describes the compound 7-propylbenzo[b][1,4]dioxepin-3-one and its use in perfumery. This compound comes under the general formula of Beereboom and has a similar odor to the abovementioned methyl derivative. To date, no further compounds of similar marine odor are known in perfumery.
SUMMARY OF THE INVENTION
Accordingly, it would be advantageous to provide novel compounds with a marine odor for use in perfumery.
One embodiment of the present invention is a compound of the general formula I:
wherein
R 1 ═H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 , CH 2 CH 2 CH 2 CH 3 , R 2 ═H, or CH 3 , and R 3 ═H, CH 3 , or CH 2 CH 3 ,
and the dashed line may be a double bond or a ring closure to form an indane ring system where, in the case of a double bond R 1 ═R 2 ═H, and in all other cases, the total number of carbon atoms of all residues is given by C 8 >R 1 +R 2 +R 3 >C 1 .
A further embodiment of the present invention is a fragrance composition containing at least one compound. according to formula I:
wherein
R 1 is H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 , CH 2 CH 2 CH 2 CH 3 ; R 2 is H, or CH 3 ; and R 3 is H, CH 3 , or CH 2 CH 3 ,
and the dashed line is a double bond or a ring closure forming an indane ring system where, in the case of a double bond R 1 ═R 2 ═H, and in all other cases, the total number of carbon atoms of all residues in formula I is given by C 8 >R 1 +R 2 +R 3 >C 1 .
Another embodiment of the present invention is a method for providing a fragrance by applying to a substrate a fragrance composition containing at least one compound according to formula I:
wherein
R 1 is H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 , CH 2 CH 2 CH 2 CH 3 ; R 2 is H, or CH 3 ; and R 3 is H, CH 3 , or CH 2 CH 3 ,
and the dashed line is a double bond or a ring closure forming an indane ring system where, in the case of a double bond R 1 ═R 2 ═H, and in all other cases, the total number of carbon atoms of all residues in formula I is give by C 8 >R 1 +R 2 +R 3 >C 1 .
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, it has now been found that compounds outside of the general formula of Beereboom also have marine odor properties, with additional completely unexpected, novel, and interesting properties. These compounds are summarized in the general formula I:
where R 1 ═H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , CH(CH 3 ) 2 , or CH 2 CH 2 CH 2 CH 3 ,
R 2 ═H, or CH 3 , and R 3 ═H, CH 3 , or CH 2 CH 3 , and
the dashed line is an optional double bond or an optional ring closure to form the indane ring system, where in the case of a double bond R 1 ═R 2 ═H, and in all other cases the total number of carbon atoms of all residues is given by C 8 >R 1 +R 2 +R 3 >C 1 .
In the case of the indane ring system, R 1 or R 2 is preferably CH 3 .
The general formula I thus encompasses compounds 1-11:
The compounds of the general formula I generally have a fresh, marine fragrance, generally with predominantly aldehydic, floral characters and are therefore particularly suitable for building up fresh, marine and aquatic effects, in particular, for instance, for modern marine Fougere perfumes and floral-aquatic women's fragrances. Those which are of particular interest for perfumes are harmonious blends of compound 1 with Tropional®, Melonal®, or Floralozon®. However, the use is neither restricted to these harmonious blends nor to specific fragrances, classes of substances or fragrance odors. Examples of further classes of substances which harmonize well include:
Essential oils and
bergamot oil, grapefruit
extracts, e.g.
oil, jasmine absolue,
mandarin oil, patchouli
oil, vetiver oil, ylang-
ylang oil, lemon oil.
Alcohols, ethers,
Acetal E ®, citronellol,
acetals, e.g.
dihydromyrcenol, Ebanol ®,
eugenol, Florol ®, geraniol,
Helional ®, cis-hex-3-enol,
Mayol ®, 2-phenylethyl
alcohol, Sandalor ®,
Spirambren ®.
Aldehydes and ketones,
Adoxal ®, Bourgeonal ®,
e.g.
Cyclohexal ®, damascone,
damascenone, Florhydral ®,
Hedion ®, Iralia ®, Iso E
Super ®, lauryl aldehyde,
Lilial ®, methyl ionone,
2-methylundecanal,
Myralden ®, undecanal,
Vertofix ®.
Esters and lactones,
allyl amyl glycolate,
e.g.
benzyl salicylate,
Cyclogalbanat ®, gamma-
decalactone, Gardenol ®,
geranyl acetate,
cis-hex-3-enyl acetate,
linalyl acetate, gamma-
undecalactone, Verdox ®.
Macrocycles, polycycles,
Ambroxan ®, Cashmeran ®,
heterocycles, e.g.
Galaxolid ®, Habanolid ®,
Thibetolid ®.
The compounds of the present invention may be incorporated into fragrance compositions, which may be applied to various substrates, such as skin, hair, and articles of clothing, etc.
The following examples are provided to further illustrate the compounds of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way.
EXAMPLES
Example 1
7-allybenzo[b][1,4]dioxepin-3-one (1)
A solution of 354 ml (2.30 mmol) of eugenol and 292 g (6.89 mol) of lithium chloride in 3.7 l of N,N-dimethylformamide was refluxed for a total of 44 hours (h), and, after 4 h, 22 h and 29 h, a further 292 g (6.89 mol) of lithium chloride were added each time. After cooling, 2 l of toluene were added and the resultant precipitate was filtered off with suction and extracted with toluene. The organic extracts were combined and concentrated on a rotary evaporator. After flash chromatography (ether/pentane, 1:1, R f =0.37) on silica gel, 173 g (50%) of 4-allylcatechol were obtained.
12.8 g (225 mmol) of 95% pure sodium methoxide were introduced into a solution of 16.8 g (112 mmol) of 4-allylcatechol in 250 ml of methanol, with stirring, followed by 21 ml (225 mmol) of methyl bromoacetate. After refluxing for 8 h, a further 21 ml (225 mmol) of methyl bromoacetate were added, and, after a further 4 h of heating, a further 12.8 g (225 mmol) of sodium methoxide and a further 21 ml (225 mmol) of methyl bromoacetate. After a further 4 h under reflux, the mixture was worked up by adding 500 ml of ether and filtering off the precipitate formed. The filtrate was concentrated on a rotary evaporator and taken up in ether/water/saturated ammonium chloride solution (1:1:1). The organic phase was separated off, and the aqueous phase was extracted three times, each time with 200 ml of ether. The combined organic phases were dried over sodium sulfate and concentrated to dryness on a rotary evaporator. After flash chromatography (ether/pentane, 1:1, R f =0.35) on silica gel, 21.4 g (65%) of methyl 4-allyl-2-(ethoxycarbonylmethoxy)phenoxyacetate were obtained.
A solution of 69.0 g (234 mmol) of methyl 4-allyl-2-(ethoxycarbonylmethoxy)phenoxyacetate was added dropwise in the course of 2.5 h to a suspension of 12.0 g (500 mmol) of sodium hydride in 500 ml of tetrahydrofuran. The reaction mixture was then refluxed for 20 h and, after cooling, poured into 1.51 of ice water. The resultant mixture was acidified to pH 2 with 2N hydrochloric acid and extracted three times, each time with 2 l of ether. The combined ether extracts were dried over sodium sulfate, freed from solvent on a rotary evaporator and taken up into 400 ml of ethanol. 400 ml of 2N hydrochloric acid were added and the mixture was refluxed for 20 h. The mixture was then poured into 1.5 l of ice water, the product was extracted four times, each time with 1.5 l of ether, and the combined ether extracts were washed with 1 l of water and 100 ml of saturated sodium chloride solution. After drying over sodium sulfate, concentration on a rotary evaporator and flash chromatography (pentane/ether, 4:1, R f =0.37) on silica gel, 20.0 g (42%) of 7-allylbenzo[b][1,4]dioxepin-3-one (1) were obtained as a colorless liquid. Odor: linear, very intensive marine-floral odor with nuances of ozone, watermelons and fatty aldehydes. -IR (film): ν=1502/1581/1436/1639 cm −1 (ν C═C, Ar), 1742 cm −1 (ν C═O), 1267/1305 cm −1 (ν ring), 1051 cm −1 (ν C—O—C). - 1 H-NMR (CDCl 3 ): δ=3.30 (d, J=6.8 Hz, 2H, 1′-H 2 ), 4.68 (d, J=7.2 Hz, 2-, 4-H 2 ) 5.05-5.10 (m, 2H, 3′-H 2 ), 5.92 (m c , 1H, 2′-H), 6.77-6.93 (m, 3H, 6-, 8-, 9-H). - 13 C-NMR (CDCl 3 ): δ=39.15 (t, C-1′), 75.41/75.63 (2t, C-2,-4), 116.00 (t, C-3′), 120.67/120.73 (2d, C-6,-9), 123.73 (d, C-8), 135.94 (s, C-7), 136.88 (d, C-2′), 146.46 (s, C-9a), 148.00 (s, C-5a), 204.61 (s, C-3). -MS (EI): m/z (%)=91 (97) [C 7 H 7 + ], 120 (25) [C 7 H 4 O 2 + ], 161 (13) [M + -C 2 H 3 O], 175 (6) [M + -CHO], 204 (100) [M + ].
Example 2
1-methyl-2,3-dihydro-1H-5,9-dioxacyclohepta[f]inden-7-one (2)
A mixture of 19.1 ml (150 mmol) of veratrol and 19.2 ml (225 mmol) of vinylacetic acid in 230 g of 83% polyphosphoric acid was stirred for 15 h at 60° C. and then poured into 500 ml of ice water. After 30 minutes (min) of stirring, the product was extracted three times, each time with 200 ml of ether. The combined organic phases were washed twice, each time with 100 ml of 2N NaOH, once with 100 ml of water and once with 50 ml of saturated sodium chloride solution, dried over sodium sulfate and freed from solvent on a rotary evaporator. After recrystallizing the residue (in AcOEt/pentane), 22.8 g (74%) of 5,6-dimethoxy-3-methylindan-1-one were obtained.
To a suspension of 53.3 g (815 mmol) of zinc dust in 74 ml of water were added 4 ml of concentrated hydrochloric acid. The supernatant was decanted off after stirring for 30 min, and to the residue were added, with ice cooling, 42 ml of water and then, dropwise, 55 ml of concentrated hydrochloric acid. 28.0 g (136 mmol) of 5,6-dimethoxy-3-methylindan-1-one dissolved in 53 ml of toluene were added and the mixture was refluxed for 3 days (d), in the course of which, after 48 h, a further 55 ml of concentrated hydrochloric acid were added. After cooling, the reaction mixture was poured into 200 ml of water and the product was extracted twice in 300 ml of ether. The combined extracts were washed with 100 ml of water and 25 ml of saturated sodium chloride solution, dried over sodium sulfate and concentrated on a rotary evaporator. After flash chromatography (pentane/ether, 9:1, R f =0.23) on silica gel, 19.6 g (75%) of 5,6-dimethoxy-1-methylindane were obtained.
Over 90 min at room temperature, 27.5 ml (202 mmol) of iodotrimethylsilane were added dropwise with stirring to a solution of 19.4 g (101 mmol) of 5,6-dimethoxy-1-methylindane in 150 ml of acetonitrile. The mixture was stirred for a further 2.5 d at room temperature, in the course of which, after 48 h, again 10 ml (73.5 mmol) of iodotrimethylsilane were added. The reaction mixture was then poured into 500 ml of water and the product was extracted twice, each time with 200 ml of ether. The combined extracts were washed with 100 ml of 40% sodium hydrogen sulfite solution, 100 ml of water and 50 ml of saturated sodium chloride solution, dried over sodium sulfate and concentrated on a rotary evaporator. After flash chromatography (pentane/ether, 2:1, R f =0.28) on silica gel, 15.5 g (93%) of 1-methylindane-5,6-diol were obtained.
A suspension of 25.7 g (186 mmol) of potassium carbonate were heated to reflux with stirring. At this temperature, over the course of 5 h, a mixture of 15.3 g (93.2 mmol) of 1-methylindane-5,6-diol and 11.6 g (92.8 mmol) of 3-chloro-2-chloromethylprop-1-ene dissolved in 50 ml of dioxane was added dropwise. When addition was complete, the mixture was stirred for a further 1 h under reflux and the inorganic solids precipitated out were filtered off with suction after cooling the reaction mixture. The solids were washed with acetone and the combined organic phases freed from solvent on a rotary evaporator. After flash chromatography (pentane/ether, 19:1, R f =0.66) on silica gel, 7.3 g (36%) of 1-methyl-7-methylene-2,3,7,8-tetrahydro-1H,6H-5,9-dioxacyclohepta[f]indene were obtained.
6.6 g (30.5 mmol) of 1-methyl-7-methylene-2,3,7,8-tetrahydro-1H,6H-5,9-dioxacyclohepta[f]indene were dissolved in a mixture of 140 ml of acetonitrile, 140 ml of water and 90 ml of carbon tetrachloride. 6.50 g (30.5 mmol) of sodium periodate were added at room temperature with stirring, with the temperature falling to 15° C. After stirring for 30 min, 0.3 g (1.5 mmol, 5 mol %) of ruthenium (III) chloride hydrate were then added, with the temperature increasing back to 30° C. The mixture was stirred for 48 h at room temperature, in the course of which, after 6 h, a further 6.50 g (30.5 mmol) of sodium periodate and 0.3 g (1.5 mmol, 5 mol %) of ruthenium (III) chloride hydrate were added. The reaction mixture was then poured into 500 ml of water and the product was extracted three times, each time with 200 ml of dichloromethane. The combined organic extracts were washed with 200 ml of 20% sodium hydrogen sulfite solution and 200 ml of water and dried over sodium sulfate. After removing the solvent on a rotary evaporator and flash chromatography (pentane/ether, 4:1, R f =0.32) on silica gel, 3.3 g (50%) of 1-methyl-2,3-dihydro-1H-5,9-dioxacyclohepta[f]inden-7-one (2) were obtained as colorless crystals of m.p. 79-80° C.
Odor: Linear, very intensive marine odor with strongly floral aspects. -IR (film): ν=1323/1280/1256/1351 cm −1 (n ring), 1735 cm −1 (ν C═O), 1041 cm −1 (ν C—O—C sym), 1482/1439/1577 cm −1 (ν C═C, Ar), 1155 cm −1 (ν C—O—C asym). - 1 H-NMR (CDCl 3 ): δ=1.24 (d, J=7.0 Hz, 3H, 1-Me), 1.60 (qd, J=12.4, 8.7 Hz, 1H, 2-H b ), 2.30 (tdd, J=12.4, 7.7, 3.9 Hz, 1H, 2-H a ), 2.74 (ddd, J=15.7, 8.7, 7.7 Hz, 1H, 3-H b ), 2.82 (ddd, J=15.7, 8.7, 3.9 Hz, 1H, 3-H a ), 3.10 (br. sext, J=7.0 Hz, 1H, 1-H), 4.66 (d, J=1.6 Hz, 4H, 6-,8-H 2 ), 6.80 (s, 1H, 4-H), 6.83 (s, 1H, 10-H). - 13 C-NMR (CDCl 3 ): δ=19.78 (q, 1-Me), 30.70 (t, C-2), 35.13 (t, C-3), 38.88 (d, C-1), 75.49/75.53 (2t, C-6,-8), 115.15/116.17 (2d, C-4,-10), 139.19 (s, C-10a), 144.39 (s, C-3a), 146.82/146.97 (2s, C-4a, 9a), 205.03 (s, C-7). -MS (EI): m/z (%)=91 (97) [C 7 H 7 + ], 103 (20) [C 8 H 7 + ], 115 (13) [C 8 H 19 + ], 175 (14), [M + -CH 3 —CO], 203 (100) M + -CH 3 ], 218 (57) [M + ].
The compounds of the general formula I listed in the examples below were synthesized according to the process of Example 2 by reaction of veratrol with the corresponding unsaturated and saturated carboxylic acids. Therefore, of these, only the odor descriptions and the spectroscopic data are listed.
Example 3
7-(3-methylbutyl)benzo[b][1,4]dioxepin-3-one (3)
Odor: Very intensive and diffuse, linear, marine odor with nuances of Adoxal® (2,6,10-trimethylundec-9-en-1-al). -IR (film): ν=1502/1435/1581/1467 cm −1 (ν C═C, Ar), 1265/1304/1201 cm −1 (ν ring), 1050 cm −1 (ν C—O—C sym), 1740 cm −1 (ν C═O), - 1 H-NMR (CDCl 3 ): δ=0.92 (d, J=6.4 Hz, 6H, 3′-Me 2 ), 1.46/1.47 (2dd, J=8.0, 6.8 Hz, 2H, 2′-H 2 ), 1.57 (nonett, J=6.8 Hz, 1H, 3′-H), 2.52 (t, J=8.0 Hz, 2H, 1′-H 2 ), 4.68 (d, J=9.2 Hz, 4H, 2-, 4-H 2 ), 6.77 (dd, J=8.2, 2.4 Hz, 1H, 8-H), 6.82 (d, J=2.4 Hz, 1H, 6-H), 6.90 (d, J=8.4 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=22.36 (2q, 3′-Me 2 ), 27.43 (d, C-3′), 32.69 (t, C-1′) 40.53 (t, C-2′), 75.35/75.63 (2t, C-2,-4), 120.27/120.50 (d, C-6,-9), 123.45 (d, C-8), 138.99 (s, C-7), 146.00/147.86 (2s, C-5a,-9a), 204.71 (s, C-3). -MS (EI): m/z (%)=77 (26) [C 6 H 6 + ], 135 (12) [M + -C 4 H 9 —C 2 H 2 O], 149 (21) [M + -C 4 H 9 —CO], 177 (100) [M + -C 4 H 9 ], 191 (7) [M + -C 3 H 7 ], 234 (52) [M + ].
Example 4
1,1-dimethyl-2,3-dihydro-1H-5,9-dioxacyclohepta[f]inden-7-one (4)
Odor: Marine-aldehyde-like, floral-rosy odor with nuances of citronelloxyacetaldehyde [(3,7-dimethyl-6-octenyl)oxyacetaldehyde]. -IR (film): ν=1322/1253/1281/1350 cm −1 (ν ring), 1040/1067 cm −1 (ν C—O—C), 1484/1438 cm −1 (ν C═C, Ar), 1736 cm −1 (ν C═O). 1 H-NMR (CDCl 3 ): δ=1.22 (s, 6H, 1-Me 2 ), 1.92 (t, J=7.2 Hz, 2H, 2-H 2 ), 2.79 (t, J=7.2 Hz, 2H, 3-H 2 ), 4.67 (d, J=2.8 Hz, 4H, 6-, 8-H 2 ), 6.75 (s, 1H, 4-H), 6.81 (s, 1H, 10-H). - 13 C-NMR (CDCl 3 ): δ=28.43 (2q, 1-Me 2 ), 29.29 (t, C-3), 41.68 (t, C-2), 43.61 (s, C-1), 75.47/75.51 (2t, C-6,-8), 113.99 (d, C-10), 116.31 (d, C-4), 138.98 (s, C-3a), 146.83/147.22 (2s, C-4a, -9a), 148.30 (s, C-10a), 205.06 (s, C-7). -MS (EI): m/z (%)=133 (33) [C 9 H 9 O + ], 145 (6) [C 11 H 13 + ], 161 (7) [M + -CH 3 -2CO], 189 (2) [M + -CH 3 —CO], 217 (100) [M + -CH 3 ], 232 (30) [M + ].
Example 5
7-(2-methylbutyl)benzo[b][1,4]dioxepin-3-one (5)
Odor: Intensive, marine-floral odor. IR (film): ν=1501/1434/1460/1580 cm −1 (ν C═C, Ar), 1265/1302/1201 cm −1 (ν ring), 1050 cm −1 (ν C—O—C), 1740 cm −1 (ν C═O). - 1 H-NMR (CDCl 3 ): δ=0.84 (d, J=6.4 Hz, 3H, 2′-Me), 0.90 (t, J=7.5 Hz, 3H, 4′-H 2 ), 1.16 (m c′ 1H, 3′-H b ), 1.39 (m1 c , 1H, 3′-H a ), 160 (m c , 1H, 2′-H), 2,28 (dd, J=11.6, 8.0 Hz, 1H, 1′-H b ), 2.53 (dd, J=11.6, 6.0 Hz, 1H, 1′-H a ), 4.69 (d, J=8.4 Hz, 4H, 2-, 4-H 2 ), 6.74 (dd, J=8.0, 2.0 Hz, 1H, 8-H), 6.78 (d, J=2.0 Hz, 1H, 6-H), 6.90 (d, J=8.0 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=11.32 (q, C-4′), 18.75 (q, 2′-Me), 28.95 (t, C-3′), 36.42 (d, C-2′), 42.22 (t, C-1′), 75.36/75.64 (2t, C-2,-4), 120.30/121.03 (2d, C-6,-9), 124.27 (d, C-8), 137.62 (s, C-7), 146.06/147.70 (2s, C-5a,-9a), 204.74 (s, C-3), −MS (EI): m/z (%)=77 (11) [C 8 H 5 + ], 91 (7) [C 7 H 7 + ], 135 (5) [M + -C 4 H 9 —C 2 H 2 O], 149 (4) [M + -C 4 H 9 —CO], 177 (100) [M + -C 4 H 9 ], 191 (2) [M + -C 3 H 7 ], 205 (1) [M + -C 2 H 5 ], 219 (1) [M + -CH 3 ], 234 (26) [M + ].
Example 6
7-Pentylbenzo[b][1,4]dioxepin-3-one (6)
Odor: Marine, floral odor with aldehydic nuances. -IR (film): ν=1502/1435/1580 cm −1 (ν C═C, Ar), 1265/1304/1201 cm −1 (ν ring), 1050 cm −1 (ν C—O—C), 1740 cm −1 (ν C═O). - 1 H-NMR (CDCl 3 ): δ=0.89 (t, J=7.0 Hz, 3H, 5′-H 2 ), 1.28-1.35 (m, 4H, 3′-, 4′-H 2 ), 1.59 (br. quint, J=7.6 Hz, 2H, 2′-H 2 ), 2.51 (t, J=7.8 Hz, 2H, 1′-H 2 ), 4.69 (d, J=9.6 Hz, 4H, 2-, 4-H 2 ), 6.77 (dd, J=8.0, 2.0 Hz, 1H, 8-H), 6.81 (d, J=2.0 Hz, 1H, 6-H), 6.90 (d, J=8.0 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=13.88 (q, C-5′), 22.38 (t, C-4′), 30.90/31.26 (2t, C-2′, -3′), 34.84 (t, C-1′), 75.35/75.64 (2t, C-2,-4), 120.31/120.47 (2d, C-6,-9), 123.51 (d, C-8), 138.85 (s, C-7), 146.03/147.83 (2s, C-5a,-9a), 204.72 (s, C-3-). -MS (EI): m/z (%)=77 (18) [C 6 H 5 + ], 91 (10) [C 7 H 7 + ], 135 (9) [M + -C 4 H 9 —C 2 H 2 O], 149 (22) [M + -C 4 H 9 —CO], 177 (100) [M + -C 4 H 9 ], 191 (8) [M + -C 3 H 7 ], 205 (1) [M + -C 2 H 5 ], 234 (42) [M + ].
Example 7
(E/Z)-1,2-dimethyl-2,3-dihydro-1H-5,9-dioxacyclohepta[f]inden-7-one (7)
Odor: Mixed odor of walnuts, Trigonella foenum - graecum , seawater and moss. -IR (film) : ν=1736 cm −1 (ν C═O), 1324/1263/1289/1352 cm −1 (ν ring), 1484/1439 cm −1 (ν C═C, Ar), 1042 cm −1 (ν C—O—C sym), 1159 cm −1 (ν C—O—C asym). - 1 H-NMR (CDCl 3 ): δ=0.95/1.08/1.17/1.24 (4d, J=7.0 Hz, 6H, 1-, 2-Me), 1.91-2.02 (m, 1H, 2-H), 2.41 (dd, J=15.0, 9.6 Hz)/2.49 (dd, J=15.0, 6.4 Hz)/2.55 (dd, J=14.0, 6.8 Hz)/2.59 (dd, J=14.0, 7.2 Hz) [2H, 3-H 2 ], 2.89 (td, J=15.7, 7.2 Hz)/3.06 (quint, J=7.2 Hz) [1H, 1-H], 4.66 (d, J=1.6 Hz, 4H 4-, 8-H 2 ), 6.76-6.80 (m, 2H, 4-, 10-H). - 13 C-NMR (CDCl 3 ): δ=14.50/15.00/17.54/18.31 (4q, 1,-2-Me), 38.64/39.38 (2t, C-3), 38.24/41.83/44.41/46.18 (4d, C-1,-2), 75.49/75.50/75.53/75.54 (4d, C-6,-8), 115.11/115.56/116.06/116.39 (4d, C-4,-10), 138.26/138.43 (2s, C-3a), 144.22/144.37 (2s, C-10a), 146.73/146.79/146.91/146.95 (4s, C-4a,-9a), 205.03/205.10 (2s, C-7). -MS (EI):m/z (%) =77 (13)/91(19)/105(20)/133(20)/161(7)/175(4) [C n H 2n7 + ], 189 (18) [M + -CH 3 —CO], 203 (1) [M + -C 2 H 5 ], 217 (100) [M + -CH 3 ], 232 (70). [M + ].
Example 8
7-Hexylbenzo[b][1,4]dioxepin-3-one (8)
Odor: Marine, aquatic. -IR (film): ν=1502/1435/1580 cm −1 (ν C═C, Ar), 1265/1304/1201 cm −1 (ν ring), 1051 cm −1 (ν C—O—C), 1741 cm −1 (ν C═O). - 1 H-NMR (CDCl 3 ): δ=0.88 (t, J=6.8 Hz, 3H, 6′-H 2 ), 1.27-1.35 (m, 6H, 3′-H 2 -5′-H 2 ), 1.57 (br. quint, J=8.0 Hz, 2H, 2′-H 2 ), 2.51 (t, J=7.8 Hz, 2H, 1′-H 2 ), 4.68 (d, J=8.0 Hz, 4H, 2-, 4-H 2 ), 6.77 (dd, J=8.0, 4.0 Hz, 1H, 8-H), 6.81 (d, J=4.0 Hz, 1H, 6-H), 6.90 (d, J=8.0 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=13.96 (q, C-6′), 22.46 (t, C-5′), 28.77 (t, C-3′), 31.19/31.56 (2t,C-2′,-4′), 34.89 (t, C-1′), 75.35/75.63 (2t, C-2,-4), 120.31/120.47 (2d, C-6,-9), 123.50 (d, C-8), 138.85 (s, C-7), 146.03/147.83 (2s, C-5a,-9a), 204.73 (s, C-3). -MS (EI): m/z (%) =77 (16)[C 8 H 6 + ], 91 (9) [C 7 H 7 + ], 135 (9) [M + -C 5 H 11 —C 2 H 2 O], 149 (21) [M + -C 5 H 11 —CO], 177 (100) [M 30 -C 5 H 11 ], 191 (2) [M + -C 4 H 9 ], 205 (3) [M + -C 3 H 7 ], 248 (43) [M + ].
Example 9
7-(3-methylpentyl)benzo[b][1,4]dioxepin-3-one (9)
Odor: Marine, animalic, civet-like, floral-aldehyde odor, also somewhat reminiscent of citronelloxyacetaldehyde ([3,7-dimethyl-6-octenyl]oxy-acetaldehyde). -IR (film): ν=1502/1435/1460/1580 cm −1 (ν C═C, Ar), 1265/1304/1202 cm −1 (ν ring), 1051 cm − (ν C—O—C), 1741 cm −1 (ν C═O). - 1 H-NMR (CDCl 3 ): δ=0.87 (t, J=7.2 Hz, 3H, 5′-H 3 ), 0.91 (d, J=6.4 Hz, 3H, 3′-Me), 1.18 (m c1 1H, 2′-H b ), 1.34-1.43 (m, 3H, 2′-H a , 4′-H 2 ), 1.56-1.62 (m, 1H, 3′-H), 2.48 (ddd, J=14.0, 10.0, 6.4 Hz, 1H, 1′-H a ), 2.56 (ddd, J=14.0, 10.4, 5.2 Hz, 1H, 1′-H b ), 4.67 (d, J=2.4 Hz, 4H, 2-,4-H 2 ), 6.78 (dd, J=8.2, 2.4 Hz, 1H, 8-H), 6.82 (d, J=2.0 Hz, 1H, 6-H), 6.90 (d, J=8.4 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=11.14 (q, C-5′), 18.93 (q, 3′-Me), 29.18 (t, C-4′), 32.42 (t, C-1′), 33.84 (d, C-3′), 38.23 (t, C-2′), 22.38 (t, C-4′), 30.90/31.26 (2t, C-2′,-3′), 75.35/75.64 (2t, C-2,-4), 120.27/120.51 (2d, C-6,-9), 123.45 (d, C-8), 139.11 (s, C-7), 146.00/147.86 (2s, C-5a,-9a), 204.72 (s, C-3). -MS (EI): m/z (%)=77 (21) [C 8 H 5 + ], 92 (14) [C 7 H 8 + ], 135 (11) [M + -C 5 H 11 —C 2 H 2 O], 149 (16) [M + -C 5 H 11 —CO], 177 (100) [M + -C 5 H 11 ], 191 (4) [M + -C 4 H 9 ], 205 (7) [M + -C 3 H 7 ], 248 (45) [M + ].
Example 10
7-(2-Methylpentyl)benzo[b][1,4]dioxepin-3-one (10)
Odor: Marine, floral-aldehyde odor. -IR (film): ν=1501/1434/1460/1580 cm −1 (ν C═C, Ar), 1265/1303/1201 cm −1 (ν ring), 1049 cm − (ν C—O—C), 1740 cm −1 (ν C═O), - 1 H-NMR (CDCl 3 ): δ=0.83 (d, 3H, 2′-Me), 0.88 (t, J=7.0 Hz, 3H, 5′-H 3 ), 1.11-1.40 (m, 4H, 3′-,4′-H 2 ), 1.68 (m c1 1H, 2′-H), 2.26 (dd, J=13.6, 8.4 Hz, 1H, 1′-H b ), 2.54 (dd, J=13.6, 6.0 Hz, 1H, 1′-H a ), 4.69 (d, J=8.4 Hz, 4H, 2-,4-H 2 ) 6.73 (dd, J=8.0, 2.0 Hz, 1H, 8-H), 6.78 (d, J=2.0 Hz, 1H, 6-H), 6.89 (d, J=8.0 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=14.15 (q, C-5′), 19.17 (q, 2′-Me), 20.02 (t, C-4′), 34.50 (d, C-2′), 38.77 (t, C-3′), 42.61 (t, C-1′), 75.36.75.63 (2t, C-2, -4), 120.30/121.04 (2d, C-6,-9), 124.28 (d, C-8), 137.61 (s, C-7), 146.05/147.70 (2s, C-5a,-9a), 204.77 (s, C-3). -MS (EI): m/z (%)=77 (9) [C 6 H 5 + ], 91 (6) [C 7 H 7 + ], 135 (5) [M + -C 5 H 11 —C 2 H 2 O], 149 (3) [M + -C 5 H 11 —CO], 177 (100) [M + -C 5 H 11 ], 205 (2) [M + -C 3 H 7 ], 248 (21) [M + ].
Example 11
7-(4-methylpentyl)benzo[b][1,4]dioxepin-3-on (11)
Odor: Marine, floral-aldehyde odor. -IR (film): ν=1502/1418/1466/1580 cm −1 (ν C═C, Ar), 1265/1304/1201 cm −1 (ν ring), 1050 cm −1 (ν C—O—C), 1741 cm −1 (ν C═O). - 1 H-NMR (CDCl 3 ): δ=0.88 (2d, J=6.4 Hz, 6H, 4′-Me 2 ), 1.18-1.24 (m, 2H, 3′-H 2 ), 1.53-1.61 (m, 4H, 2′-H 2 , 4′-H), 2.50 (t, J=7.8 Hz, 2H, 1′-H 2 ), 4.69 (d, J=8.0 Hz, 4H, 2-,4-H 2 ), 6.78 (dd, J=8.0, 4.0 Hz, 1H, 8-H), 6.82 (d, J=4.0 Hz, 1H, 6-H), 6.90 (d, J=8.0 Hz, 1H, 9-H). - 13 C-NMR (CDCl 3 ): δ=22.44 (2q, 4′-Me 2 ), 27.74 (d, C-4′), 29.07 (t, C-2′), 35.14 (t, C-1′), 38.39 (t, C-3′), 75.35/75.63 . (2t, C-2,-4), 120.30/120.48 (2d, C-6,-9), 123.50 (d, C-8), 138.86 (s, C-7), 146.03/147.83 (2s, C-5a,-9a), 204.76 (s, C-3). -MS (EI): m/z (%)=77 (13) [C 6 H 5 + ], 91 (8) [C 7 H 7 + ], 135 (7) [M + -C 5 H 11 —C 2 H 2 O], 149 (16) [M + -C 5 H 11 —CO], 177 (100) [M + -C 5 H 11 ], 191 (1) [M + -C 4 H 9 ], 205 (3) [M + -C 3 H 7 ], 248 (38) [M + ].
The compounds 7-(2-ethylbutyl)benzo[b][1,4]dioxepin-3-one and 7-heptylbenzo[b][1,4]dioxapin-3-one also have the faceted marine odor typical of this class of compound and are therefore suitable, as are the abovementioned compounds, for preparing harmonious fragrance blends having marine notes. In this regard, the abovementioned compounds 1 and 3 are particularly outstanding, as shown by the examples below.
Example 12
Floral-Marine-Fruity Women's Fragrance Containing Compound
Contents by weight
in parts per
No.
Compound/constituent
thousand
1.
Citronellol extra
30
2.
Cyclohexal
150
3.
Damascone 10% in DPG
2
4.
gamma-Decalactone
2
5.
beta-Dihydroionone
55
6.
DPG (dipropylene glycol)
76
7.
Eugenol, pure
35
8.
Galaxolid 50 BB
275
9.
Hedion
110
10.
Iso E Super
145
11.
Jasmolactone (Firmenich) 1
25
percent strength in DPG
12.
Linalool, synthetic
30
13
Compound 1, 10% in DPG
65
1000
The composition produces a feminine-sensual, transparent, modern perfume with a rosy-floral, fresh jasmine-like head and floral-fruity heart note with spicy aspects on a musky-wooden base.
Compound 1 gives the composition its marine aspects, and gives it its radiance and richness in character. It transforms the traditional floral fragrance into a modern-transparent, trend perfume. In comparison with the compound 7-methylbenzo[b][1.4]dioxepin-3-one, that is to say Calon 1951® mentioned at the outset, compound 1 is much more intense and, at the same dosage, is accompanied by a much stronger marine impression without transition into fishy or salty, as is the case with Calon 1951® at the high dosage here. The compound 1 is much more floral than Calon 1951® and therefore harmonizes much better with the floral elements of the composition. It develops the floral-aquatic accord, while remaining transparent.
Example 13
Feminine Floral-marine Perfume Containing Compound 3
Contents by weight
in parts per
No.
Compound/constituent
thousand
1.
Algenon PB
100
2.
Benzyl salicylate
110
3.
Bergamot oil, Italian
50
4.
Boisambren forte
10
5.
Cyclohexal
12
6.
Dihydromyrcenol
35
7.
DPG (dipropylene glycol)
358
8.
Eugenol, pure
10
9.
Fixolid
10
10.
Galaxolid 50 PHT
65
11.
Georgywood
25
12.
Hedion
20
13.
Linalool, synthetic
10
14.
Linalyl acetate, synthetic
30
15.
Sandela
25
16.
Tropional
75
17.
Vertofix Coeur
35
18.
Compound 3, 10% in DPG
20
1000
Compound 3 enhances the fresh, marine impression of the composition. It combines harmoniously with the hesperidic topnote, emphasizes the floral heart note and finally blends in the base with woody and musk-like notes to give a character harmonious composition. Compound 3 provides volume, radiance and body to the composition. It gives the impression of a fresh sea breeze. Compared with Calon 1951® (see Example 12), compound 3 is much more intense, but nevertheless does not have a heavy or suppressive effect on the other constituents of the composition. In contrast, compound 3 brings the perfume more radiance, diffusivity and volume than Calon 1951®.
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 are intended to be included within the scope of the following claims.
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The invention relates to 1,2-substituted 2,3-dihydro-1H-5,9-dioxacyclohepta[f]inden-7-ones and 7-substituted benzo[b][1,4]dioxepin-3-ones and to the use of these compounds in fragrance compositions.
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[0001] The present invention relates to a method of generically and transparently expanding and contracting a query, comprising the steps of:
[0002] A. receiving a first query comprising one or more search values,
[0003] B. obtaining a second query by a first processing of the first query,
[0004] C. executing the second query in a database,
[0005] D. receiving a first result comprising one or more rows with instances of data from the database on the basis of the second query, and
[0006] E. providing a second result by a second processing of the first result.
[0007] The present invention also relates to an apparatus for generically and transparently expanding and contracting a query, comprising:
[0008] receiving means adapted to receive a first query comprising one or more search values,
[0009] processing means adapted to provide a second query by a first processing of the first query,
[0010] executing means adapted to execute the second query in a database,
[0011] receiving means adapted to receive a first result comprising one or more rows with instances of data from the database on the basis of the second query, and
[0012] processing means adapted to provide a second result by a second processing of the first result.
TECHNICAL FIELD
[0013] This invention relates to a generic method and apparatus for expanding and contracting a query in order to include functionality in the form of query functions like Fuzzy logic and a rating/scoring function in a standardised query language, e.g. SQL, thereby providing access to multiple heterogeneous data sources and/or homogeneous sources.
BACKGROUND AND PROBLEM
[0014] Searching of information in structured information sources like databases is most often done by using SQL (Standard Query Language) which is a very common standard query language to which almost every database has an interface.
[0015] However, one of the disadvantages of SQL is that the results obtained by a query are presented to the user in the order that they are retrieved from the database. This gives the user a very poor general view of which result is the most important for him.
[0016] Another disadvantage of SQL is that prior to the generation of an SQL query the type of the contents of the individual fields, i.e. field types/values, must be known. This is generally far from being the case. A type of field that varies very much from database to database is e.g. a field containing a date. Additionally the range of values, i.e. dimension, must be known in order to specify/construct a usable query. E.g., one needs to know if the values of a given row in a database are within a range of −1000 to 1000 or −1 to 1.
[0017] Yet another problem is the handling of consistency of values for the individual fields. A great inconsistency may occur dependent on who enters the data and how the data is entered into a database. Different sales persons might input data for a given product differently. In a field which was designed to receive “Yes” and “No”, different people could enter: “Y”, “y”, “N”, “n”, “+”, “−”, etc.
[0018] Therefore it is often necessary to cleanse a database at a regular interval of time to ensure consistency for each type of field. Cleansing is both a very time consuming and computationally heavy task, especially for large databases. Further, cleansing of a database may delete valuable information, since information may be hidden in the way different data is entered into the database. For example, if a field was to contain the value “Yes” or “No” reflecting an answer to “colored”, the entered data may be “green”, “blue” etc. During cleansing the information of the actual color will be lost and changed to “YES”.
[0019] SQL only gives the possibility of ‘Categorical Query’, i.e. there has to be an exact match to provided search criteria in order to obtain a result, or a null result will be given.
[0020] Even though fuzzy functions and phonetics are known in connection with databases it needs a dedicated driver; e.g. Oracle has some of this functionality in their “Stored Procedures”, which is dedicated to an Oracle database. Other database vendors have similar functionalities bound to their proprietary systems.
Solutions
[0021] The object of the invention is to provide a method which enables a generic and more intelligent communication with one or more standard databases and a more intelligent handling of the data/values in the fields of the database(s). The database(s) may even be heterogeneous.
[0022] This is achieved by a method of the said type
[0023] the first processing is done by expanding the first query according to one or more query functions,
[0024] the second processing is done by contracting the first result, and in that the method further comprises the step of F. calculating an overall score for one or more query functions according to a second function.
[0025] Hereby, a method is provided where a generic ‘intercepting’ layer of functionality may be applied to incorporate many different functionalities between the user at one end and the database at the other. In this way, the user sees a ‘virtual database’ having the functionality which the generic and intercepting layer provides.
[0026] The method is generic, since the functionality is transparent, i.e. intercepting, and builds on a standard query language.
[0027] Additionally the method is able to handle lacking consistency in different fields of e.g. an SQL, database, thereby avoiding the need for cleansing.
[0028] Additionally the method is able to sort the result of an SQL query, e.g. by ranking and indication of metric distance given by an overall score so that the most relevant information is presented first to the user.
[0029] These features bring the quality of a search up to a higher level than possible in a standard SQL search.
[0030] In accordance with an embodiment the database is a virtual database comprising one or more heterogeneous sources and/or homogenous sources. Theses sources may be standard databases or even file systems and other unstructured information sources.
[0031] In this way a user only sees or experiences the communication with a collection of databases as communication with a single database and does not have to worry about or even know which data requested by him comes from which physical database. Additionally the user may request data from heterogeneous databases/sources. All that is needed is the implementation of corresponding query functions.
[0032] In accordance with another embodiment the method is repeated until the overall score for all query functions satisfies a given criterion.
[0033] Hereby, it is possible to expand the original query gradually, so that only the most relevant information is retrieved. If no result is returned, then the query can be expanded to search for values with differ more from the originally specified search value(s). This functionality will be denoted a ‘Query Manager’ in the following.
[0034] In accordance with another embodiment the expanding of the first query for each repetition of the method is done according to only the query functions having an overall score which does not satisfy the given criteria.
[0035] Hereby, only the parts of the originally expanded query not satisfying the given criteria have their distance to the specified search value(s) enlarged, which reduces the computational effort needed to bring all the overall scores for the query functions into satisfaction.
[0036] In accordance with another embodiment the contracting of the first result by the second processing is done on the basis of the overall score for one or more query functions.
[0037] In accordance with another embodiment the overall score for one or more query functions is calculated on the basis of one or more individual scores.
[0038] In accordance with another embodiment the one or more individual scores are calculated as a metric distance representing how close instances of data in the first result are to the one or more search values.
[0039] In accordance with another embodiment the one or more query functions execute one or more of the functions:
[0040] automatic translation of words,
[0041] conversion of values,
[0042] fuzzy logic functions,
[0043] personalising,
[0044] security control functions.
[0045] In this way it is possible to have query functions which can e.g. automatically convert words between one or more languages. For example all words contained in one or more databases may be translated into another language, e.g. from English into Danish.
[0046] The query functions may also provide an automatic conversion of values. This avoids the need for cleansing of the database since fields having a format that differs can be converted by the intercepting layer/query functions and be presented to the user in a uniform way. For example “Y”, “y”, “+” and “N”, “n”, “−” may be converted into “Yes” and “No”, respectively.
[0047] This enables intelligent handling of fields with contents that frequently vary, e.g. time, dates, etc.
[0048] Another advantage is the possibility of being able to include fuzzy logic in an existing SQL database by using the query functions. This gives the advantage that e.g. if the user specifies a search value and that value is not present in any field in the database being searched, then the user can be presented with the value or values being closest to the specified search value. This is not possible in a standard SQL without any functional layer.
[0049] Additionally functionality may be personalising and/or security control functions responding indirectly to input parameters from the user level or from an application handling the communication between the user and the database as well as receiving input and presenting results to the user.
[0050] The above functionalities are only examples and in principle all kinds of different functionalities may be implemented.
[0051] This together with the ‘Query Manager’ is a very useful feature, since the ‘Query Manager’ gives the possibility of repeated expansion/evaluation until a given criterion is met and/or a satisfactory result is obtained.
[0052] For example, it is possible to ‘Query by example’, since a result can always be presented to the user, i.e. the result being closest to the specified search value, as opposed to a standard SQL database where a null result will be provided if a search value is not present in the database.
[0053] Alternatively, the query functions of a layer may contain combinations of different types of functions so that both fuzzy logic and translation of words are provided, and etc.
[0054] Another object of the present invention is to provide an apparatus which enables a more intelligent and generic communication with one or more standard databases and a more intelligent handling of the data/values in the fields of the database(s). The databases may even be heterogeneous.
[0055] This object is achieved by an apparatus of the said type where
[0056] the first processing is done by expanding the first query according to one or more query functions,
[0057] the second processing is done by contracting the first result, and that
[0058] an overall score is calculated for one or more query functions according to a second function.
[0059] This gives the same advantages for the same reasons as described previously in relation to the method.
[0060] Other embodiments of the apparatus according to the invention are characterized by the features defined in the dependent claims which are advantageous for the same reasons as described previously in relation to the method.
[0061] Further, the invention relates to a computer-readable medium whose contents are adapted to cause a computer system to perform the method described above. A medium may e.g. be a CD-ROM, a floppy disk, a hard disk, a DVD RAM/ROM drive, a network, etc.
[0062] Hereby, when a computer is caused to retrieve electronic information—as a consequence of the contents of a computer-readable medium as described above—the advantages mentioned in connection with the corresponding method according to the invention are achieved.
[0063] Finally, the invention relates to a computer program element comprising program code means adapted to enable a computer system to perform the method described above.
[0064] When a computer program element causes a computer to retrieve electronic information as described above, the advantages mentioned in connection with the corresponding method according to the invention are achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] The present invention will now be described more fully with reference to the drawings, in which
[0066] [0066]FIG. 1 shows a flowchart according to one embodiment of the invention;
[0067] [0067]FIG. 2 shows a fuzzy curve;
[0068] [0068]FIG. 3 illustrates an example of how the Query Manager imposes constraints;
[0069] [0069]FIG. 4 shows a schematic representation of the relationship between different query functions and a database;
[0070] [0070]FIG. 5 illustrates a schematic block diagram of an apparatus according to one embodiment of the invention.
DETAILED DESCRIPTION
[0071] [0071]FIG. 1 shows a flowchart according to one embodiment of the invention. In the following the method will only be described broadly and a more detailed description will be given later in connection with FIGS. 2, 3 and 4 .
[0072] In step (101) a query statement specified by a user is ‘intercepted’ or received by an application using the method according to the invention. This query is expanded in step ( 102 ) according to one or more query functions/rules. Additionally one or more parameters may be specified, e.g. by the user and/or by the application, preferably for each query function together with the original query. An example of a parameter could e.g. be a minimum score for a value of a particular field. These parameters are used together with the query, resulting in one or more restrictions. The result and/or restrictions of each query function return a subpart query which is concatenated into the single expanded query.
[0073] The expanded query statement is then sent to the database in step ( 103 ) and executed, which returns a search result in step ( 104 ) based on the expanded query. The search result consists of a number of rows which have fields fulfilling the expanded query.
[0074] The search result is then evaluated in step ( 105 with respect to how well the returned result is in accordance with the original query. For example, a score for each function may be obtained, as will be described later in connection with FIG. 2.
[0075] In step ( 106 ) it is determined whether the result is OK and thereby ready to be presented to the user. This functionality of checking whether another iteration of expansion and contraction of the query is needed, is denoted a ‘Query Manager’. If the result is OK then the result is sent and/or presented to the user in step ( 107 ), and if not then the method loops back to step ( 102 ) where another iteration of expansion, collection and scoring takes places.
[0076] More specifically, if the scores for all query functions are not fulfilled, then the query functions which had non-fulfilled scores generate another sub-query which is expanded in a broader sense, e.g. the interval of values of interest may be expanded. So another expanded query comprising elements from the non-fulfilled query functions with broader values is executed in the database. This is done until all the query functions score sufficiently according to a given criterion, and the method will then proceed to step ( 107 ) and present the search result as mentioned earlier.
[0077] The various query functions may include many different functions to be performed on the database. Each query function may be applied to only certain fields in the database. Examples of query functions include automatical translation of words from one language into another, conversion of values, fuzzy logic, etc.
[0078] [0078]FIG. 2 shows a fuzzy curve ( 201 ). This figure will be used to describe an example of how one query function implementing fuzzy logic returns a subpart of the expanded query and how the obtained result is scored. As an example, the query function is chosen to be a fuzzy query function, associated with the logarithmic fuzzy curve ( 201 ), which provides a more intelligent handling of real numbers in a database.
[0079] Shown is the logarithmic fuzzy curve ( 201 ) which gives the relationship between a real value q and the corresponding fuzzy score s. Also shown is a search value v ( 202 ) specified by the user in the original query together with qmin=v/w ( 203 ) and qmax=v*w ( 204 ). w (not shown) is the width of the fuzzy curve and defines the width of the fuzzy curve ( 201 ), i.e. for which values/interval of q around v we have a corresponding fuzzy score s different from zero. qmin ( 203 ) and qmax ( 204 ) in this way give the interval of values we find interesting.
[0080] Given the search value v ( 202 ) and a minimum score Smin (between 0 and 1), e.g. specified by the user, we need to create a part of an SQL statement for returning all rows of a database table, which scores more than the Smin for a given fuzzy function.
[0081] As the field to select in the SQL query we choose an SQL expression exp that returns the real value on which we would like to perform the search. In order to restrict the query we create a subpart of the SQL: <exp> BETWEEN <a> AND <b>, where a ( 205 ) and b ( 206 ) limit the interval of values we want to include in our search result. a ( 205 ) and b ( 206 ) are given by:
a = S min · v + ( 1 - S min ) · v 25 · w ,
b = S min · v + ( 1 - S min ) · v w .
[0082] Note that in the special cases where Smin=1 or Smin=0, then a=b=v or a=qmin and b=qmax, respectively.
[0083] In this way the value of Smin defines the expansion of the interval in which we look for relevant values.
[0084] After the query has been executed, a set of rows, each containing a field with a real value within the specified interval, fulfilling the query is returned. These real values for each row are then processed in order to obtain a score, S, for each of the rows. This score is a measure of how close the real value in a particular row is to the original search value v.
[0085] The scoring is preferably:
S = { v - q v · w - v , if q > v v - q v / w - v , otherwise .
[0086] This score, S, e.g. enables the presentation of retrieved rows from the database to be sorted according to which row has a real value which is closest to the specified search value.
[0087] In this way fuzzy functions may be used to expand values. For example, the user may specify interest in a value of 100 and be presented with a search result containing fields in the interval of 90 to 110 sorted according to how close the fields are to the initial, specified value of 100, i.e. sorted according to their score.
[0088] [0088]FIG. 3 illustrates an example of how the Query Manager gradually imposes different constraints on the expanded query. It is very useful to gradually broaden the interval of values which are retrieved by the method, i.e. to reduce the Smin (see FIG. 2). In this way it is possible, by evaluating a total score for each iteration of the Query Manager, to stop when interesting information/values have been retrieved without the inclusion of uninteresting noise in the form of fields containing a value that is very far from the original, specified search criteria.
[0089] In this way we want to find the best n matches for a query by performing a number of queries starting with an exact match and ending with a very broad query. When each query function, e.g. fuzzy query function, is asked to construct an SQL query, it is given the minimum score Smin. The query function should then construct an SQL query which returns all the rows of the database table that have a score equal to or higher than the specified Smin. This process is done for each query function independent of each other. In this way the Query Manager expands the SQL query until it is guaranteed that the result contains the n best rows of the database table.
[0090] The overall score of a row is calculated by the expression:
S = ∏ s i w i 15 ,
[0091] where s i ε [0;1] is the score of the i'th query function, w i ε [0;∞] is a weight number applied to the i'th query function, and S is the overall score obtained by multiplying all the individual scores of each query function together.
[0092] The restrictions given by the individual query functions form a ‘bounding box’ for the query in question. The result is found by expanding the overall minimum score and thereby the bounding box until the best n overall scores are greater than the given overall minimum score.
[0093] As an example we assume that we execute a query using the following sequence of minimum overall scores:
S′=1.0; S′=0.8; S′=0.6; S′=0.4; S′=0.2;S′=0.0;
[0094] Then the bounding box would increase in size as S′ gets smaller. S′=1.0 means that only rows with fields having values identical with the specified search number/keyword (see FIG. 2) are returned, and S′=0.0 means that all rows are returned.
[0095] This process of a gradually expanding fuzzy search is illustrated in FIG. 3 where the diamonds ( 301 ) represent different rows in the database table, the circles ( 302 ) represent the distance of the field and the query, and the boxes ( 303 ) represent the ‘bounding boxes’ for each of the overall minimum scores S′.
[0096] As can be seen in FIG. 3 no rows for S′=1.0 are returned. When the Query Manager receives no rows, it generates another expanded query with S′=0.8 which does not return any rows either. For S′=0.6 two rows ( 304 and 305 ) are returned which both have the same distance as illustrated by the bounding box ( 306 ). This procedure is repeated until all the interesting rows are returned either by S′=0.0 or by a given criterion, e.g. specified by the user or internally by the method. Such a criterion may be a metric distance of e.g. 5%, 10%, etc.
[0097] [0097]FIG. 4 shows a schematic representation of the relationship between different query functions and a database. Shown is the intercepting layer ( 401 ) of query functions ( 402 ). In this example eight different query functions ( 402 ) are shown, each providing different functionalities.
[0098] The query functions ( 402 ) receive/intercept the original query e.g. together with additional parameters ( 403 ) specified by the user or internally by an application. These additional parameters ( 403 ) may be maximum metric distance, maximum number of returned rows, etc.
[0099] After receiving the original query, each query function ( 402 ) generates an expanded sub SQL statement according to that particular query function and parameters, if any. The expanded sub statement relates to one or more fields ( 404 ) in the database ( 405 ) as indicated by the arrows ( 406 ) pointing from the query functions ( 402 ) to the database ( 405 ) in FIG. 4. The fields ( 404 ) to which a given query function relates may e.g. be predefined or dependent on the parameters ( 403 ). All these SQL statements from each query function are then concatenated into a single expanded SQL statement, which is executed in the database ( 405 ), and a search result containing rows ( 407 ) with fields ( 404 ) fulfilling the expanded query is returned.
[0100] The search result is sent back to the intercepting/receiving layer ( 401 ) where each query function ( 402 ) receives the values each particular query function ( 402 ) was responsible for selecting. If two or more query functions ( 402 ) both selected a specific field, the value of that field is returned to both query functions ( 403 ).
[0101] After the query functions ( 402 ) have received the values from the database ( 405 ) a scoring of the result is executed by a Score Calculator ( 408 ) as described in connection with FIG. 2.
[0102] If the scoring for a given query function ( 402 ) is sufficient, then the result of that query function ( 402 ) is ready to be presented to the user. If the scoring for a given query function ( 402 ) is not sufficient, then another iteration may be performed by the Query Manager where a new sub SQL statement is created with gradually fewer and/or looser constraints. All the new sub SQL statements for each query function ( 402 ) which did not score sufficiently are concatenated into a new expanded query, which is executed in the database. This procedure is repeted until every query function ( 402 ) scores sufficiently.
[0103] When all scores are satisfactory, the result of each query function ( 403 ) is contracted into a single search result, which is presented to the user.
[0104] The user perceives this single result as the result on the basis of the original query and does not have to know of the functionality in the intercepting/receiving layer ( 401 ). That is, the user sees a virtual database with the functionality provided by the query functions ( 402 ).
[0105] The query functions ( 402 ) may implement all kinds of different functionality and may be set to perform exactly as desired. For example, the query functions ( 402 ) may respond to input parameters ( 402 ) from the user level or from an application handling the communication between the user and the database as well as receiving input and presenting results to the user. In this way the query functions ( 402 ) may work as personalisers, security functions, etc.
[0106] A personalising part may e.g. be implemented by using an input consisting of a personal profile and using this profile to contribute to the total score in the Score Calculator ( 408 ), e.g. by modifying weights, w i , in the individual scoring functions as described in connection with FIG. 2. If the results found are not within the personal profile they will be scored very low and thereby not be relevant as such.
[0107] A security function may be implemented in a similar way, since fields or results not accessible to the user will score too low to match.
[0108] In an alternative embodiment the intercepting/receiving layer ( 401 ) is connected to two or more databases.
[0109] [0109]FIG. 5 illustrates a schematic block diagram of an apparatus according to one embodiment of the invention. Shown here are processing means ( 502 ) which may be any kind of a CPU. The processing means ( 502 ) are connected to receiving means ( 501 ) which are responsible for receiving information from other units outside the apparatus. This information may e.g. be data from a database ( 504 ) or input directly by a user, e.g. by mouse and keyboard or the like, or from another (server/client) application e.g. providing a graphical interface to the user and/or handling the exchange of information in a network. The database ( 504 ) may be a locally or externally stored database. Alternatively the database ( 504 ) may comprise one or more heterogeneous and/or homogeneous databases which the user, through the functionality of the layer, may perceive as one single database. In this way data from many different databases may be accessed by one query if query functions are specified which handle this situation properly. So the user does not have to think about which databases contain which data when he specifies a query.
[0110] The processing means ( 502 ) are also connected to storing means ( 506 ) for storage and later retrieval of results, variables, etc. The storing means ( 506 ) may be any kind of RAM, hard disk, etc. (preferably a combination).
[0111] The processing means ( 502 ) are additionally connected to executing means ( 503 ) which are responsible for executing the query expanded by the processing means ( 502 ) in one or more databases ( 504 ). In a preferred embodiment the processing means ( 502 ) and the executing means ( 503 ) are formed by a single CPU means ( 500 ).
[0112] The processing means ( 502 ) are also connected to sending/presenting means ( 507 ), e.g. a display, for displaying information, choices, results, etc. to a user, or for sending the result(s) of a query to another application which may be responsible for presenting the result(s) to a user and/or long-time storage, etc.
[0113] The processing means ( 403 ) are responsible for the execution of a program which enables the expansion of a query according to one or more query functions, the expanded query being executed in one or more databases ( 504 ) instead of the original query. The query functions provide the possibility of implementing different functionalities like fuzzy functions, etc. into a standard database ( 504 ) transparently to the user.
[0114] After the expanded query has been executed by the executing means ( 503 ) in the database ( 504 ) the receiving means ( 510 ) receive a result of the expanded query. The result is a number of rows which fulfil the expanded query. The result is then sent to the processing means ( 502 ) where a score for each query functions is provided. If not all scores satisfy a given criterion, a new expanded query is generated which is then executed in the database ( 504 ).
[0115] This is repeated until all the scores are satisfactory, and then the result is presented to the user or sent to another application via the sending/presenting means ( 507 ).
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The invention relates to an apparatus and method of genericallly and transparently expanding and contracting a query comprising the steps of: receiving a first query comprising one or more search values, obtaining a second query by a first processing of the first query, executing the second query in a database, receiving a first result comprising one or more rows with instances of data from the database on the basis of the second query, and providing a second result by a second processing of the first result, wherein the first processing is done by expanding the first query according to one or more query functions, the second processing is done by contracting the first result, and in that the method further comprises the step of calculating an overall score for one or more query functions according to a second function.
The invention also relates to a computer-readable medium and a computer program element comprising computer program code means adapted to perform the method
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. §119(e) to U.S. provisional patent application No. 60/747,957 (“the '957 application”), which was filed on May 23, 2006 and entitled “Skew Adjustment Device For Coverings For Architectural Openings.” The '957 application is incorporated by reference into the present application in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to coverings for architectural openings and more particularly to a skew adjustment device positioned within the head rail of the covering to maintain a uniform rollup of covering fabric onto a roller disposed within the head rail.
[0004] 2. Description of the Relevant Art
[0005] Coverings for architectural openings have assumed different forms over many years. Early forms of coverings simply consisted of fabric draped across all or some portion of an architectural opening such as a door, archway, window or the like.
[0006] Retractable coverings have also been a popular product wherein the covering is either suspended vertically and retracted to one or both sides of the architectural opening or rolled up or down about a roller at the top or bottom of the opening. The latter category of retractable coverings include a flexible fabric or fabric like material that is connected to a roller and can be retracted about the roller in a retracted condition of the covering or extended from the roller across the architectural opening in an extended condition.
[0007] One problem with retractable coverings that include a flexible material that is wound onto or unwound from a roller resides in the material skewing as it is wound onto the roller or unwound from the roller. When the material skews, it translates horizontally along the longitudinal axis of the roller as it is raised and wraps around the roller in a spiral fashion sometimes referred to as barber poling. As a result, the bottom rail along the bottom edge of the material is not desirably horizontally disposed during operation of the covering. Skewing of the material can be caused by various features of the covering including the roller not being horizontally mounted, the fabric not being fixed to the roller horizontally, or the fabric being asymmetrically configured, but regardless of the cause of the skew, it is aesthetically undesirable and can cause the fabric to engage the housing for the roller where it can fray. Accordingly, attempts have been made to correct skew.
[0008] Typically, the skew is corrected with a ballast bar or bars slidably positioned in the bottom rail of the covering so that the ballast bar or bars can be releasably fixed at any desired location along the horizontal length of the bottom rail. This of course shifts the center of gravity of the bottom rail which counters the bias in the covering material so that the bottom rail remains horizontal as desired for operation and aesthetics.
[0009] While ballast bars in the bottom rail are typically concealed within the bottom of the bottom rail, under certain circumstances, they can become visible and accordingly alternative anti-skew systems are continually being investigated.
[0010] It is to provide an alternative skew adjustment system that the present invention has been developed.
SUMMARY OF THE INVENTION
[0011] The skew adjustment system of the present invention is incorporated into the head rail of a rollup covering for architectural openings wherein the covering includes a flexible fabric or fabric-like material adapted to be wound about a roller in the head rail when retracting the covering or unwound from the roller when extending the covering. It has been found that by creating a point of increased tension on the flexible material at a predetermined fixed position along the horizontal length of the roller the tendency of the fabric to skew as it is being rolled on or unrolled from the roller can be offset.
[0012] In accordance with the present invention, an engagement arm is slidably positionable at releasably fixed positions along the horizontal length of the head rail, with the arm being resilient and adapted to slidably engage the fabric material when it is at least partially wound about the roller. The engagement arm creates a frictional drag on the material which inhibits the wrapping of the material at the location of the engagement arm while allowing other locations along the length of the roller to accept the fabric with a looser wrap so as to counter the skew bias. Other aspects, features and details of the present invention can be more completely understood by reference to the following detailed description of a preferred embodiment, taken in conjunction with the drawings and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an isometric view of a retractable covering for an architectural opening shown in an extended position with a portion of the head rail removed to show the skew adjustment device of the present invention.
[0014] FIG. 2 is a front elevation of the covering of FIG. 1 with the skew adjustment device shown in dash lines.
[0015] FIG. 3 is a front elevation similar to FIG. 2 showing the covering partially retracted and with the bottom rail inclined relative to horizontal illustrating a skew in the fabric of the covering.
[0016] FIG. 4 is a front elevation similar to FIG. 3 with the covering fully retracted and with the bottom rail still forming an incline with horizontal.
[0017] FIG. 5 is a front elevation similar to FIG. 2 with the covering in a fully extended position but with the skew adjustment device having been shifted to the right.
[0018] FIG. 5A is an enlarged fragmentary section taken along line 5 A- 5 A of FIG. 5 .
[0019] FIG. 6 is a front elevation similar to FIG. 5 showing the covering in a partially retracted position.
[0020] FIG. 7 is a front elevation similar to FIG. 6 with the covering fully retracted.
[0021] FIG. 8 is an enlarged vertical section taken along line 8 - 8 of FIG. 7 .
[0022] FIG. 9 is an isometric showing the skew adjustment device of the present invention.
[0023] FIG. 10 is a view of the skew adjustment device taken along line 10 - 10 of FIG. 9 .
[0024] FIG. 11 is a left-side elevation of the skew adjustment device of FIG. 9 .
[0025] FIG. 12 is a front elevation of the skew adjustment device.
[0026] FIG. 13 is a section taken along line 13 - 13 of FIG. 12 .
[0027] FIG. 14 is an enlarged vertical section taken through a portion of the head rail of the covering of FIG. 1 with the skew adjustment device positioned in the head rail.
[0028] FIG. 15 is a fragmentary isometric showing the skew adjustment device being inserted into the head rail.
[0029] FIG. 16 is an isometric of a second embodiment of the skew adjustment device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Referring first to FIG. 1 , a covering 20 for an architectural opening such as a door, window, archway or the like is illustrated in a fully extended position. The covering can be seen to include a head rail 22 that rotatably supports a roller 24 ( FIG. 5A ) that is reversibly driven by a control cord 26 in a conventional manner. The roller supports a flexible fabric material 28 which for illustrative purposes is shown as being comprised of a pair of face sheets 30 of material such as sheer interconnected at vertically spaced locations by horizontally disposed translucent flexible vanes 32 . Other fabric or fabric-like materials could be used in lieu of the material illustrated as will be appreciated with the description that follows. The bottom edge of the fabric material supports a rigid bottom rail 34 . A fabric covering of the type illustrated is described in detail in applicant's U.S. Pat. No. 5,313,999, the disclosure of which is hereby incorporated by reference. As can also be seen in FIG. 1 , at the location where the head rail is broken away, a skew adjustment device 36 in accordance with the present invention is incorporated into the head rail and the device and its operation will be described hereafter.
[0031] The covering 20 shown in FIG. 1 is shown in a front elevation in FIG. 2 . As will be appreciated, the bottom rail 34 is disposed horizontally and in a parallel relationship with the head rail 22 as is desired for aesthetics. In FIG. 3 , however, the covering is shown partially retracted and it can be seen the bottom rail forms an acute angle with horizontal with this position of the covering being referred to in the industry as skewed. In other words, as the fabric material is being wrapped around the roller 24 , the right edge is wrapping more rapidly or more tightly than the left edge causing the bottom rail to skew or tilt as illustrated. Of course, such a skew is undesirable from an aesthetic standpoint, and in fact, when the covering is fully retracted as shown in FIG. 4 , the bottom rail is clearly no longer parallel with the head rail as it was when the covering was fully extended in FIG. 2 . It should also be noted in FIGS. 2-4 that the skew adjustment device 36 which is shown in dashed lines, as it is hidden within the head rail, is longitudinally centered within the horizontal head rail.
[0032] As will be more clearly appreciated with the description that follows, the skew adjustment device 36 is slidably disposed within the head rail 22 and can be releasably fixed at any position along the horizontal length of the head rail. The skew adjustment device is a frictional device that slidably engages and compresses the fabric material 28 as it is being wrapped onto the roller or unwrapped from the roller 24 . The frictional engagement with the fabric material provides drag and compression at a preselected position along the horizontal length of the roller so that the rate at which the fabric wraps about the roller at the location of engagement and the tightness of the wrap can be controlled thereby controlling skew.
[0033] With reference to FIGS. 5-7 , FIG. 5 shows the covering 20 fully extended and of course the bottom rail 34 is horizontal and parallel with the head rail 22 . The skew adjustment device 36 is positioned to the right of center so as to correct the skew illustrated in FIGS. 2-4 . In FIG. 6 , the covering has been partially retracted and due to the affect of the skew adjustment device on the fabric material 28 being wrapped about the roller, the bottom rail remains horizontal and parallel with the head rail as desired. FIG. 7 shows the covering fully retracted and as will be appreciated, the bottom rail is flush and parallel with the head rail as desired.
[0034] With reference to FIGS. 9-13 , the skew adjustment device 36 can be seen to be a punched or molded member that is made of a semi-rigid but resilient material such as plastic, aluminum, spring steel or the like and includes an arched plate-like back 38 with an integral forwardly and upwardly inclined engagement arm 40 . The bottom edge 42 of the engagement arm is integral with the bottom edge of an opening 44 through the plate-like back of the device and due to the integral connection of the engagement arm with the back along an edge of the engagement arm and the resilient semi-rigid characteristics of the material from which the device is made, the engagement arm is spring biased so that if deflected up or down, it will be encouraged or biased to return to the neutral position shown in FIG. 9 . A second opening 46 is provided through the back plate 38 adjacent to the bottom edge thereof thereby defining a somewhat flexible arched segment 47 . As is possibly best appreciated by reference to FIGS. 11 and 13 , the plate-like back of the device is generally arcuate and concave in a forward direction having an optional horizontally wavy or serpentine segment 48 immediately above the location of attachment of the engagement arm 40 with the back 38 . An illustration of the skew adjustment device without the serpentine segment 48 is shown in FIG. 16 . A flat horizontal tab 50 is provided in the device above the serpentine segment for a purpose to be described hereafter.
[0035] It should also be noted that the free or distal edge 52 of the engagement arm is hook shaped so as to provide a smooth curved forwardly convex edge portion which as will become more clear hereafter, slidably engages the fabric material 28 in the covering to correct any skew that may be inherent therein.
[0036] The head rail 22 for the covering as possibly best seen in FIG. 8 , includes an arcuate front wall 54 connected to a rear component 56 and a top wall 58 . The space between the front wall and an open rear of the head rail along the bottom of the head rail is also open so the fabric for the covering can be rolled onto or unrolled from the roller 24 through the open bottom of the head rail. End caps 62 are also provided at opposite ends of the head rail for aesthetics.
[0037] The front wall 54 of the head rail 22 , again as probably best seen in FIG. 8 , has an arcuate main body 64 continuous upwardly with an inclined flat segment 66 that is in turn continuous with a generally flat upper ledge 68 that interconnects with the top wall 58 of the rear component 56 of the head rail in a conventional manner. Adjacent to the uppermost edge of the inclined flat segment 66 of the front wall, a generally inverted T-shaped rib 70 extends inwardly perpendicularly to the inclined flat segment and defines a downwardly opening pocket or groove 72 for receipt of the horizontal tab 50 along the upper edge of the skew adjustment device 36 as will be more clear hereafter. Adjacent to the lower edge of the arcuate main body 64 of the front wall of the head rail is another generally T-shaped inward projection 74 which defines an upperwardly opening seat or groove 76 for the lower edge of the skew adjustment device.
[0038] The front wall 54 of the head rail 22 is preferably an extruded member that can be made from aluminum, plastic or other suitable material so that the features described above are formed continuously along the horizontal length of the front wall. Accordingly, the pocket 72 and the seat 76 are confronting along the inner surface of the front wall for slidable receipt of the top and bottom edges of the skew adjustment device.
[0039] With reference to FIG. 15 , the skew adjustment device 36 can be seen being inserted into the space on the front wall 54 between the pocket 72 and the seat 76 by positioning the flat horizontal tab 50 along the top edge of the skew adjustment device into the pocket at the top of the front wall of the head rail and then sliding the skew adjustment device along the inner surface of the front wall of the head rail until the bottom edge of the skew adjustment device is received in the upwardly opening seat 76 . The skew adjustment device, as mentioned, is made of a semi-rigid but resilient material and is sized so that it is compressed into the space between the upperwardly opening seat and the downwardly opening pocket with some spring bias being provided by the serpentine segment 48 of the skew adjustment device along with the inherent resilient characteristics of the material from which the skew adjustment device is made. Due to the flexibility of the device, it can also be inserted into the head rail laterally and snapped into place at a desired location.
[0040] When the skew adjustment device 36 is fully and slidably mounted on the front wall 54 of the head rail 22 , it is positioned as seen best in FIG. 14 so as to apply pressure along the top and bottom edges against the pocket 72 and the seat 76 so that it can be releasably frictionally fixed at any position along the length of the head rail. As will be appreciated in FIGS. 5A and 8 , when the skew adjustment device is desirably and slidably mounted on the head rail, the engagement arm 40 projects inwardly toward the roller 24 .
[0041] The hook shaped distal edge 52 of the engagement arm 40 as mentioned above provides a smooth curved convex surface for engagement with the material or fabric 28 of the covering and due to the arcuate nature of the distal edge of the engagement arm, the arm engages the material of the covering tangentially so as not to snag the material. As will be appreciated in FIGS. 5A and 8 , when the material is substantially unwrapped from the roller 24 , the engagement arm remains in frictional engagement with the material as it obviously does when the material is fully wrapped about the roller as shown in FIG. 8 .
[0042] The engagement of the arm 40 with the material 28 is designed to establish a frictional drag on the material and compresses the material on the roller as it is being wrapped or unwrapped from the roller. As will be appreciated by providing frictional drag and compression at a predetermined location along the length of the roller 24 the fabric is encouraged to wrap or unwrap in an unnatural way. This of course is designed to counter or offset the natural bias that may be in the fabric causing it to skew if not corrected. In other word, at the location on the fabric where the skew adjustment device 36 is engaged, the fabric is compressed toward the roller causing the material beneath the engagement arm to wrap more slowly and more tightly about the roller or unwrap more slowly and more tightly from the roller. Due to the fact that the skew adjustment device can be releasably fixed through friction at any position along the length of the head rail 22 , any degree of skew or inherent bias in the covering can be corrected.
[0043] By way of example, if the skew in the covering is as illustrated in FIG. 3 with the right edge of the fabric 28 being wrapped more rapidly and more loosely than the left edge, the skew adjustment device 36 can be shifted to the right as shown in FIGS. 5-7 to provide a frictional drag and increased tension toward the right side of the fabric allowing the left side to catch up so that the covering can be extended and retracted without skew.
[0044] An alternative embodiment of the skew adjustment device is shown in FIG. 16 where again the device is made of a semi-rigid but resilient material wherein an arched plate-like back 78 of the device is smooth and does not include the serpentine segment 48 of the first-described embodiment. The device again includes an integral forwardly and upwardly inclined engagement arm 40 with the bottom edge 42 of the engagement arm being integral with the bottom edge of an opening 44 through the plate-like back 78 of the device and due to the integral connection of the engagement arm with the back along an edge of the engagement arm and the resilient semi-rigid characteristics of the material from which the device is made, the engagement arm is spring biased so if deflected up or down, it will be encouraged or biased to return to the neutral position shown in FIG. 16 . Again, an opening 46 is provided through the back plate adjacent to the bottom edge thereof which defines a somewhat flexible arched segment 47 as in the first-described embodiment. The resiliency of the material and the relatively thin arched segment 47 in comparison to the remainder of the back plate enables the device to be laterally inserted and snapped into place within the head rail. It will be appreciated the serpentine segment 48 of the first-described embodiment is an optional feature of the device and is not mandatory.
[0045] Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example and changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.
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A device for correcting skew in roll-up retractable coverings for architectural openings includes a friction device positioned within the head rail for movement between releasably fixed positions and disposed for engagement with the fabric of the covering to regulate the rate at which the fabric is wrapped about a roller in the covering at selected locations along the length of the roller to correct for any inherent skew in the covering.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method, a system, and a computer program product for performing functional verification of logic circuits.
[0002] Digital logic circuits implement a logic function of a digital hardware. Such circuits represent the core of any computing processing unit. Thus, before a logic circuit or “hardware design” is constructed in real hardware, its respective logic design must be tested and the proper operation thereof has to be verified against a design specification. This task is called functional verification and described for example in J. M. Ludden et al.: “Functional verification of the POWER4 microprocessor and POWER4 multiprocessor systems”, IBM Journal of Research and Development, Vol. 46 No. 1, January 2002.
[0003] In one step of the functional verification process, the hardware logic design is represented as a so-called register-transfer level netlist, or netlist. Register transfers take place during the execution of each hardware cycle: Input values are read from a set of storage elements (registers, memory cells, etc.), a computation is performed on these values, and the result is assigned to set of storage elements. A netlist can be generated from a high-level description of the hardware circuit in a standard hardware description language such as VHDL. Logic simulation systems are able to use this netlist in order to simulate the behaviour of the hardware logic design for a given set of input signal values.
[0004] A netlist can be treated as a directed graph structure with simple building blocks as nodes and signals as connecting arcs; see Kupriyanov et al.: “High Speed Event-Driven RTL Compiled Simulation”, Proc. of the 4 TH . Int. Workshop on Computer Systems: Architectures, Modelling, and Simulation 2004. The building blocks are often called boxes and the signals are called nets, hence the name netlist. Among the simple building blocks are Boolean gates, registers, arrays, latches, and black boxes representing special logical functions.
[0005] Assume a simple exemplary circuit has a plurality of 16 input signals. Then a plurality of 2 to the power of 16 different input signal values exist, which should be tested in total for the correct operation of the circuit, or its logic model, respectively. But today's hardware designs are much more complex. Even single sections of a hardware design may comprise hundreds, or several thousands of input signal values. This enormous input signal value space cannot be verified by logic simulation completely. Regression runs of logic simulations using randomly generated values for the input signals of the hardware design are used instead.
[0006] A special verification technique that addresses the complete input signal value space is called functional formal verification. But also functional formal verification of hardware logic designs at the register-transfer level is inherently difficult using automated methods. Many automated functional formal verification methods are based on algorithms using Binary Decision Diagrams (BDDs) to represent the hardware logic design, where a temporal logic formula is verified for a given hardware logic design. Systems implementing these methods are called a (symbolic) model checker. Model checkers take benefit from the fact that a hardware logic design can be represented as a finite state machine, for which the complete finite state space is verified.
[0007] A temporal logic formula allows specifying the behaviour of a system over time; see for example Mana/Pnueli: “The Temporal Logic of Reactive and Concurrent Systems”, Vol. 1, Springer 1995. For example for logic design verification the Computational Tree Logic can be used to specify the signal value of a certain signal at certain discrete points in time (cycles), e.g. a signal has a value of 1 in the next cycle, a signal has a value of 0 in all following cycles, a signal has a value of 1 in at least one of the following cycles etc.
[0008] If the model checker finds a specific combination of signal values for the inputs for a netlist of a design under test for which a temporal logic formula is not fulfilled then it produces a counterexample. A counterexample is a list of signals and their values of either 0 or 1 at certain cycles. A model checker delivers a counterexample with a minimal number of cycles such that the temporal logic formula is not fulfilled.
[0009] Other automated functional formal verification methods are based on algorithms using conjunctive normal forms (CNF) to represent the hardware logic design, where it is checked whether a CNF can be satisfied (SAT) for a given hardware logic design. Except for special cases, attempts to formally verify a hardware logic design result in either memory (BDD-based algorithms) or runtime (SAT-based algorithms) explosions.
[0010] Floating-point circuits are notoriously difficult to design and verify. For verification, simulation barely offers adequate coverage. For a complete state of the art floating point unit it takes many months to perform a reasonable number of logic simulation regression runs. Therefore, in logic simulation a large set of special test cases is used to maximize the test coverage for the logic design of the floating point unit.
[0011] For floating point multiplication, an adding process for exponential parts of the multiplied values, a multiplying process for the mantissa parts of the multiplied values, a normalizing process for the product of the multiplication of the mantissa, and a rounding process are performed to finally obtain the result of the multiplication. Such floating point multiplication methods are described in the IEEE 754, “IEEE Standard for Binary Floating-Point Arithmetic”. Binary multiplication is discussed in detail in chapter 5 of the textbook “Arithmetic Operations in Digital Computers” by R. K. Richards.
[0012] Any hardware logic design containing a binary multiplier circuit is difficult to verify using functional formal verification methods. As described in C. Jacobi et al.: “Automatic Formal Verification of Fused-Multiply-Add FPUs”, Proc. of the 2005 Design, Automation and Test in Europe Conference and Exhibition (DATE'05), the usual method to overcome this problem is to mask out the multiplier from the design by overwriting the multiplier output signals with non-deterministic (random) values. These non-deterministic values mimic the behaviour of the multiplier such that any logic connected to the outputs of the multiplier behaves as if the multiplier itself would be part of the design.
[0013] The multiplier is then verified by other means such as simulation and adapted formal verification methods. In many cases the multiplier itself is simple enough to be verified quickly using logic simulation methods. A special functional formal verification method is shown in R. Kaivola, N. Narasimhan: “Formal Verification of the Pentium©4 Floating-Point Multiplier”, Proc. of the 2002 Design, Automation and Test in Europe Conference and Exhibition (DATE'02). The disadvantage of this method is that it comprises many manual steps that are specific for a given design. Therefore, a verification framework that has been developed using this method is difficult or even impossible to use in different hardware development projects.
[0014] With the actual multiplier being replaced by non-deterministic overwrites, the connection to the multiplier input signal values is lost. Therefore it is complicated to reconstruct the input signal values of the multiplier if a design error has been detected during the verification of the modified hardware logic design with the multiplier masked out, such that these input signal values would produce the same design error in the unmodified design.
[0015] Typically, it is a lot easier to detect the cause of the design error if all the input signal values of the design are known. One way to analyse the problem then is to perform a logic simulation using all the input signal values that lead to the design error.
SUMMARY OF THE INVENTION
[0016] It is therefore an object of the present invention, to provide a method for performing functional verification of logic circuits that is improved over the prior art and a corresponding computer system and a computer program product.
[0017] The present invention allows performing the functional formal verification of hardware logic designs by replacing the parts of the design that cannot be easily formally verified with other parts that emulate the behaviour of the replaced parts. Especially, the method can be used automatically for any hardware logic design.
[0018] In one embodiment of the invention the method is applied to a hardware logic design including a multiplier circuit for which it is assumed that the multiplier is implemented correctly.
[0019] The advantages of the present invention are achieved by determining the input signal values of the multiplier circuit from a given set of output signal values of the multiplier and a given set of constraints for the input signal values.
[0020] The output signal values of the multiplier will be defined by using a counterexample that is produced automatically by a verification system, for example a model checker. Such a counterexample is typically given as a signal value trace for the hardware logic design, starting with a given set of input signal values for the design, and ending with the signal value combination in the design that does not match the design specification.
[0021] The test for a counterexample will be done on a modified hardware logic design, where the multiplier is removed by replacing its input and output signals by pseudo-signals. These pseudo-signals are non-deterministic (random) values and mimic the potential set of output signal values of the multiplier.
[0022] The output signal values of the multiplier circuit will be treated as an integer number. Then the prime factors of this number are determined. In a preferred embodiment of the invention, a prime number test is performed before the prime number factorisation as a time saving method.
[0023] Among the prime factors, a combination is determined which satisfies the given set of constraints for the input signal values, which are treated as two integer numbers. Such a combination is used to generate these two integer numbers, which are the result of the multiplication of the prime factors from the determined prime factor combination.
[0024] The two numbers are then treated again as input signal values for the multiplier and combined with the other input signal values for the hardware logic design from the counterexample to form a test case file. This test case file will then be used by a logic simulation system in order to simulate the unmodified hardware logic design including the multiplier circuit. In this simulation a complete signal value trace for the hardware logic design can be generated and used to find the root cause of the design error.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] For the present invention, and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings.
[0026] FIG. 1A : Is a block diagram of a floating point unit in a processor;
[0027] FIG. 1B : Is a block diagram of a floating point unit in a processor for test purposes according to the present invention;
[0028] FIG. 2A : Is a block diagram of a the inputs and outputs of a multiplier;
[0029] FIG. 2B : Is a block diagram of a building block to replace a multiplier in accordance with the present invention;
[0030] FIG. 3 : Is a flow chart of a method in accordance with the invention;
[0031] FIG. 4 : Is a flow chart of a method in accordance with the invention.
DETAILED DESCRIPTION
[0032] FIG. 1A illustrates a floating point unit (FPU) 10 supporting the IEEE 754 standard in a processor. This floating point unit 10 implements the multiplication of two floating point numbers stored in the registers 11 and 12 by a multiplier 13 and is part of a subsystem of the processor that is responsible for the implementation of the IEEE 754 standard.
[0033] For the present invention, the netlist representation of the FPU 10 is modified such that the multiplier 13 and its input floating point numbers 11 and 12 are replaced by a random variable building block 15 . FIG. 1B illustrates the modified floating point unit 14 . The random variable building block 15 is a special node in the directed graph structure of the netlist that is interpreted as signals with random values by a model checker.
[0034] The inputs of the multiplier 13 can be separated in two groups related to the two numbers that will be multiplied by the multiplier 13 . For a floating point number to be handled by the FPU 10 , the multiplier 13 is multiplying the mantissa parts only. FIG. 2A is an exemplary illustration for these two groups for the netlist representation of the FPU 10 . In the first group are the input signals 200 , 201 , 202 , and 203 . In the second group are the input signals 210 , 211 , 212 , and 213 . The outputs of the multiplier 13 are the output signals 220 , 221 , 222 , 223 , 224 , 225 , 226 , 227 . The input and output signals of the multiplier 13 are nets in the directed graph structure of the netlist of the FPU 10 . The actual netlist representation of the multiplier 13 is not shown in FIG. 2A . This representation is itself a directed graph structure that represents the actual logic design implementation of the multiplier at the register-transfer level.
[0035] For the above described modification of the netlist of the FPU 10 that results in the modified FPU 14 the two groups of input signals are removed from the directed graph structure and the random variable building block node 15 as shown in FIG. 2B is added as a node to the graph structure. The output signals 220 , 221 , 222 , 223 , 224 , 225 , 226 , 227 of the multiplier 13 are replaced by the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random variable building block 15 respectively.
[0036] In a preferred embodiment of the invention, the random variable building block 15 is a node in the graph structure of the netlist representation of the modified FPU 14 and not represented as a directed graph structure within the graph structure of the modified FPU 14 as is the case for the multiplier 13 because the building block 15 serves as a place holder for verification purposes, which cannot be implemented as hardware. In other embodiments a netlist can be used instead, which allows to model the behaviour of the multiplier 13 . The only requirement to the replacement netlist is that it can be easily formally verified.
[0037] Since there are no arcs left in the graph representing the netlist of the modified FPU 14 that connect the graph representing the multiplier 13 with the graph representing the other logic circuits of the FPU 10 , the multiplier has no influence to the behaviour of the modified FPU 14 . Therefore the graph structure representing the multiplier 13 can be removed in the graph structure representing the modified FPU 14 ; hence the multiplier 13 can be removed in the netlist representation of the modified FPU 14 .
[0038] As known from the mathematical graph theory, a directed graph is a pair G=(V, E), where V is a finite set of nodes and E is a subset of V×V, a relation on V called the set of arcs. A path in a graph G is a finite sequence of arcs (u — 0, v — 0), . . . ,(u_n, v_n) such that v_(i−1)=u_i. In a preferred embodiment of the invention all the nodes and arcs of the graph structure representing the FPU 10 will be removed from the graph structure representing the modified FPU 14 , for which a path exists that ends in one of the input signals 200 , 201 , 202 , 203 , 210 , 211 , 212 , 213 of the multiplier 13 . The sub-graph that is defined by all these paths is also called the cone-of-influence.
[0039] The modification step of the netlist representation of the FPU 10 that leads to the netlist representation of the modified FPU 14 can be performed automatically by a software program executed on a computer system as this modification is a graph manipulation for which well-known algorithms exist. The inputs that have to be provided for this program besides the netlist of the FPU 10 are the input signals 200 , 201 , 202 , 203 , 210 , 211 , 212 , 213 and the output signals 220 , 221 , 222 , 223 , 224 , 225 , 226 , 227 of the multiplier 13 .
[0040] The state of the art modification technique described above allows to mask out the multiplier 13 from the FPU 10 and to verify the modified FPU 14 separately. The modified FPU 14 can be verified by a model checker that treats the outputs 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random variable building block 15 as an integer number. This integer number is the concatenation of the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 into a binary number by using a signal value of either 0 or 1 for each of the signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 . For example, the signal values can be 1, 0, 1, 0, 1, 0, 1, 0 for each of the signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 , 238 respectively such that the binary number is 10101010. Since the signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 are the outputs of the random variable building block 15 , the model checker treats the signals as all possible 8-digit binary numbers.
[0041] The model checker is now used to perform a functional formal verification of the implementation of the FPU 10 against a design specification. The temporal logic properties used for the verification of the FPU 10 can be derived manually from a design specification document for the FPU 10 . The temporal logic formulas and the netlist representation of the modified FPU 14 are used as an input for the model checker. If a temporal logic property is not fulfilled, then the model checker presents a counterexample for the modified FPU 14 .
[0042] The signal value list of the counterexample comprises the signal values for all the signals within the modified FPU 14 including the input signals of the modified FPU 14 and the concrete signal values for the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random value building block 15 for every cycle until the temporal property is not fulfilled.
[0043] The counterexample is used to generate a test case for a logic simulation of the unmodified netlist representation of the FPU 10 . For the test case the signal values for the input signals of the modified FPU 14 have to be taken from the counterexample at a specific cycle, the start cycle. The input signal values for the multiplier input signals 200 , 201 , 202 , 203 , 210 , 211 , 212 , 213 need to be determined from the signal values of the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random variable building block 15 . The signal values for the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random value building block 15 have to be taken from the counterexample at a specific cycle, the multiplier result cycle.
[0044] For the preferred embodiment of the invention the multiplier result cycle and the start cycle need be determined manually from the logic design specification document of the FPU 10 , and provided as an input for the method. In other embodiments these two cycles can be determined automatically from the counterexample by using a set of properties, e.g. specific signal values, which must be fulfilled at certain cycles.
[0045] The signal values of the input signals of the modified FPU 14 at the start cycle, and the signal values of the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random variable building block 15 at the multiplier result cycle can be extracted from the counterexample by using a program interface that delivers the signal value for a given signal at a given cycle.
[0046] For the present invention the signal values for the input signals 200 , 201 , 202 , 203 , 210 , 211 , 212 , 213 of the multiplier 13 are determined from the signal values of the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random value building block 15 . In order to achieve this, the signal values of the output signals 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 of the random value building block 15 are treated as an integer number N as described above. This integer number N is factorised into its prime factors. The factorisation can be performed automatically by a program executed on a computer system using well-known algorithms, e.g. the Pollard-Rho algorithm described in J. M. Pollard “A Monte Carlo Method for Factorization”, BIT 15(1975), pp. 331-334. As a time saving method, a prime number test can be performed for the integer number N in a preferred embodiment of the invention. If the integer number N is a prime number, N does not need to be factorised.
[0047] The result of the factorisation of N is a list of prime factors and their number of occurrences. If 12 is the integer number N, then its prime factors are 3, 2, 2 because 12=3*2*2; an example list of prime factors is ((2, 2), (3, 1)). The prime factors of N can be divided in two groups, e.g. (2, 3) and (2) for the integer number 12. For the present invention all possible combinations of dividing the prime factors in two groups are determined; e.g. {(2, 3), (2)) and {(2, 2), (3)} for the integer number 12.
[0048] These combinations are determined in a brute-force approach, which is feasible since typical multipliers have at most 64 input signal values and therefore a relatively small maximum number of 2*64=128 prime factors. The brute force approach works such that all integer factors of N are computed from the prime number factorisation of N. Let
p :=(( f — 1, o — 1), . . . ,( f — n, o — n ))
be a list of prime numbers, and f_i and o_i be the number of occurrences of these prime numbers in the list. Then
F ( p ):=( f — 1 to the power of o — 1)* . . . *( f — n to the power of o — n )
is the factor of the list p. Let p be the list of the n prime factors of the integer number N. A new list can be generated from the prime factor list p by replacing an o_i by an integer number in the range from 0 to o_i. Let F — 1, . . . ,F_m be the factors of all these possible lists.
[0049] Obviously, the list factors F — 1, . . . ,F_m are all the integer number factors of N and can be computed by a program running on a computer system from the list p. Now a pair (F_i, F_j) is searched such that N=F_i*F_j. For the first pair (F_i, F_j) that is found, F_i is treated as a concatenation of signal values of the signals 200 , 201 , 202 , 203 of the multiplier 13 , and F_j is treated as a concatenation of signal values of the signals 210 , 211 , 212 , 213 of the multiplier 13 . This delivers a list of signal values for the signals 200 , 201 , 202 , 203 , 210 , 211 , 212 , 213 of the multiplier 13 . These signal values are now used together with other signal values for signals from the counterexample as a test case for a logic simulation of the unmodified FPU 10 in order to obtain all the information required to understand the design error completely.
[0050] FIG. 3 summarizes the steps described above. The netlist 50 representation of the FPU 10 is modified (step 51 ) such that the multiplier 13 is masked out and replaced by the pseudo-inputs 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 . The modified netlist will be verified by a model checker, which produces (step 52 ) a counterexample 53 in case a design error i's found. From this counterexample 53 the input signal values of the multiplier 13 are determined (step 54 ), which are used to generate (step 55 ) a test case 56 for a logic simulation system.
[0051] The determination (step 54 ) of the input signal values of the multiplier 13 is shown in FIG. 4 . The output signal values 60 of the random variable 15 are treated as an integer number N, for which the prime factors are determined (step 61 ). The prime factors of N are used to generate a list F — 1, . . . ,F_m of all integer factors of N (step 62 ). From this list a pair (F_i, F_j) of integer factors of N is searched, such that N=F_i*F_j (step 63 ). This pair is used to generate (step 64 ) corresponding input signal values 65 for the multiplier.
[0052] In a preferred embodiment of the present invention, a pair of factors (F_i, F_j) that fulfils a set of additional properties besides N=F_i*F_j is searched in the list of factors F — 1, . . . ,F_m. An example for such a constraint is that F_i and F_j have to be mantissas of normal or denormal (subnormal) floating point numbers N_i and N_j as defined in the IEEE 754 standard. If F_i and F_j are both mantissas of normal numbers, then 1<=F_i*F_j<4. If F_i and F_j are both mantissas of denormal numbers, then 0<F_i*F_j<1. If either F_i or F_j are a mantissa of a denormal number, then 0<F_i*F_j<2. Since the exponential part of a denormal number is 0, it can be determined if N_i and N_j are normal or denormal from the exponential part of N_i and N_i at the start cycle in the counterexample.
[0053] In order to determine the constraints, the signals representing the exponential parts of the floating point numbers that will be multiplied have to be known. These signals do not have to be in the cone-of-influence for the multiplier inputs as they do not contribute to the mantissa multiplication. Therefore they are part of the netlist representation of the modified FPU 14 .
[0054] Another example for constraints is related to the precision of the floating point numbers that get multiplied. The IEEE 754 standard defines different precisions such as single precision, double precision, etc. Associated constraints can be derived from the processor instruction set code for the multiplication operation that gets handled by the FPU 10 . This code is represented by signal values of certain signals in the modified FPU 14 and can therefore be found in the counterexample.
[0055] In case there is no pair (F_i, F_j) in the list of factors of N that fulfils the constraints, then another counterexample for the same design error can be used. Some model checkers allow specifying the maximum number of counterexamples that will be produced. It is not guaranteed that more than one counterexample exists for the same design error, but the likelihood increases with the number of binary digits used for the floating point numbers. For real-world examples for the FPU 10 , it can therefore be assumed that another counterexample can always be found.
[0056] The invention is not restricted to hardware designs including a multiplier. It can be used to replace any part of a netlist that cannot be verified easily using functional formal verification. Such a part gets replaced by another netlist that is suitable to model the behaviour of the replaced parts in a formal verification tool, and for which a method exists to deliver signal values for the input signals of the netlist from the signal values of the output signals of the netlist.
[0057] This invention is preferably implemented as software, a sequence of machine-readable instructions executing on one or more hardware machines. While a particular embodiment has been shown and described, various modifications of the present invention will be apparent to those skilled in the art.
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A method, a computer program product and a system for performing functional verification logic circuits. The invention enables the functional formal verification of a hardware logic design by replacing the parts that cannot be formally verified easily. In one form the invention is applied to a logic design including a multiplier circuit. The multiplier is replaced ( 51 ) by pseudo inputs. The input signal values of the multiplier circuit are determined ( 54 ) automatically from a counterexample ( 53 ) delivered ( 52 ) by a functional formal verification system for a modified design where the multiplier is replaced by pseudo signals. The input signal values are combined ( 55 ) with other known inputs to form a test case ( 56 ) file that can be used by a logic simulator to analyse the counterexample ( 52 ) on the unmodified hardware design including the multiplier.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Stage application of International Application No. PCT/EP2004/004993, filed on May 10, 2004, which claims priority of German application number 103 20 898.4, filed on May 9, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a biocompatible or biologically compatible sensor electrode arrangement and a process for its manufacture.
[0004] 2. Description of the Prior Art
[0005] In many areas of chemical and biochemical analysis technology, biocompatible or biologically compatible material arrangements, in particular biocompatible or biologically compatible sensor arrangements or sensor electrode arrangements are used. As a result of these material arrangements, sensor arrangements or sensor electrode arrangements, certain measuring processes are used in practical application with respect to a chemical, biological or biochemically relevant analyte.
[0006] In the case of analytical processes with high rates of throughput, i.e. in the case of so-called high throughput screening processes, different characteristics are desirable for biocompatible material arrangements, sensor arrangements or sensor electrode arrangements, in particular with regard to their electrical sensitivity, their mechanically stability and/or their high and cost-effective availability. In the case of conventional material arrangements, sensor arrangements or sensor electrode arrangements, carrier substrates are used which, although having a mechanically relatively stable construction, they may entail an otherwise comparatively difficult handleability and also not be necessarily producible in a cost-effect manner.
SUMMARY OF THE INVENTION
[0007] The invention is based on the task of indicating a biocompatible or biologically compatible sensor electrode arrangement and a process for its manufacture in the case of which cost-effective and both reliably handleable biocompatible or biologically compatible material arrangements are used in a particularly simple manner.
[0008] This task is achieved in the case of a biologically compatible or biocompatible sensor electrode arrangement according to the present invention. Moreover, the task is achieved according to the invention in the case of a process for the manufacture of a biologically compatible or biocompatible sensor electrode arrangement. The biologically compatible or biocompatible sensor electrode arrangement according to the invention exhibits at least one carrier substrate area which is formed with a top side with a surface area or a top side surface area. Moreover, an intermediate substrate area or a connecting substrate area is provided which is formed on the surface area of the carrier substrate area or a part thereof, in particular in a structured manner, and which is formed with a top side facing away from the carrier substrate area with a surface area or with a top side surface area. Finally, a biomaterial area is provided which is formed on the top side surface area of the intermediate substrate area or the connecting area or a part thereof, in particular in a structured manner, with at least one biocompatible or biologically compatible material component. The carrier substrate area with the intermediate substrate area or the connecting substrate area thereon or the intermediate substrate area or the connecting substrate area as such and/or a part thereof in each case are formed, for example, in the form or in the manner of a wafer element or a printed circuit. Alternatively or additionally, the intermediate substrate area or the connecting substrate area are formed as a or with a photolithographically processed structure or as a or with a photographically processed element. As a further alternative or additionally, the intermediate substrate area or the connecting substrate area are provided as a or with a structure processed by being bonded on or laminated on or as an or with an element processed by being bonded on or laminated on. As a further alternative or additionally, the intermediate substrate area or the connecting substrate area are formed as a or with a structure processed by printing or as an or with an element processed by printing. Moreover, alternatively or additionally, the intermediate substrate area or the connecting substrate area are formed as a or with a structure processed micromechanically and/or by laser ablation or as an or with an element processed micromechanically and/or by laser ablation.
[0009] This takes place in particularly directly on the carrier substrate area in each case.
[0010] It is consequently a core idea of the present invention to form the biocompatible sensor electrode arrangement according to the invention based on a carrier substrate area, between the carrier substrate area and the biomaterial area, an intermediate substrate area or connecting substrate area being provided by way of at least one biocompatible material component.
[0011] A further core idea of the present invention consists of the fact that the carrier substrate area with the intermediate substrate area or the connecting substrate area or that the intermediate substrate area or connecting substrate area as such or parts thereof are provided as a wafer element, as a printed circuit, as a photolithographically processed structure, as a structure bonded or laminated on, as structure processed micromechanically and/or by laser ablation and/or as a structure processed by printing, in particular on the substrate carrier area in each case.
[0012] As a result of this structure provided according to the invention, advantages arise compared with the state of the art to the effect that low material and manufacture costs, for example, arise in the case of the biocompatible sensor electrode arrangement according to the invention because common mass manufacture techniques connected with the suggested modes of formation and structures can be used during the manufacture.
[0013] Moreover, a corresponding mechanical strength of the biocompatible sensor electrode arrangement according to the invention is obtained automatically with a high reliability in use and a high application flexibility, the aspect of miniaturisation of the structures of the biocompatible sensor electrode arrangements of the invention being thereby taken into consideration, on the basis of the corresponding process technology, sufficiently and in a reliable manner.
[0014] Although it is possible to produce the intermediate substrate area or the connecting substrate area by epitaxial growing, by vapour deposition and/or sputtering in a particularly well controlled, well defined manner and/or with planar surfaces, it is possible under certain circumstances for straight structures and processes for their manufacture and corresponding techniques to offer themselves for reasons of costs and/or simplification, in the case of which such a control of the area properties and surface properties of the intermediate substrate area or the connecting substrate area is not possible, such as e.g. in the case of application and/or structurisation by photolithography, bonding, lamination, printing, ablation, laser ablation or such like if a good definition, controllability and/or planarity of the intermediate substrate area or the connecting substrate area or their surface are not important.
[0015] In the case of a preferred embodiment of the biocompatible sensor electrode arrangement according to the invention it is provided that the carrier substrate area exhibits a chemically inert, biologically inert and/or essentially electrically insulated material or is formed of such a material. As a result of this measure, minimal interactions with the chemical or biological surroundings arise and the use as a carrier for an electrode offers itself in particular.
[0016] With a view to the multiple application possibilities, it may be additionally or alternatively provided for the carrier substrate area to exhibit a mechanically flexible material or to be formed of such a material, in particular in the manner or in the form of a film. This then allows the manufacture of, e.g., single use sensors for single application, e.g. for diagnostic or clinical purposes or for use in the field, in situ or at the point of care.
[0017] With the regard to the structurisation of the biocompatible material arrangement as a sensor electrode arrangement, it is provided additionally or alternatively in the case of another embodiment of the sensor electrode arrangement according to the invention that a layer of an electrically conductive metal oxide, e.g. ITO or indium tin oxide is formed for the intermediate substrate area or for the connecting substrate area.
[0018] On the other hand, it may be possible, with respect to the structuralisation of the biocompatible material arrangement as a sensor electrode arrangement in the case of another embodiment of the sensor electrode arrangement according to the invention to be additionally or alternatively provided that a metallic layer structure is formed on the top side surface area of the carrier substrate area for the intermediate substrate area or for the connecting substrate area.
[0019] In this connection, it may be advantageous if the layer structure for the intermediate substrate area or for the connecting substrate area is formed with or from at least one primary metal area arranged at bottom most, a subsequent auxiliary layer and an actual electrode layer arranged top most.
[0020] The auxiliary layer can serve, in particular, as an alloy and/or diffusion barrier between the primary metal area and the actual electrode layer such that an alloy formation as a result of interdiffusion of the materials of the primary metal area and the actual electrode layer into or with each other is avoided. This maintains, for example, the specificity of the actual electrode layer, in particular in the case where a surface functionalisation or surface improvement of the actual electrode layer is involved.
[0021] The primary metal area can be formed with or of copper, for example.
[0022] The structurisation of the primary metal area can be provided in different forms, e.g. in the form of a photolithographically structured or applied primary metal area. In addition or alternatively, primary metal areas applied by bonding, lamination, ablation and/or processed by printing are conceivable.
[0023] According to another embodiment of the sensor electrode arrangement according to the invention, the auxiliary layer is formed with or from nickel.
[0024] In the case of a further alternative embodiment of the sensor electrode arrangement according to the invention it is provided that the actual electrode layer arranged top most is formed with or from a noble metal. Gold is preferably used in this respect.
[0025] The auxiliary layer and/or the actual electrode layer arranged top most can be formed by electrodeposition.
[0026] Alternatively or additionally, it is possible to consider a micromechanical formation and/or a laser ablation.
[0027] With respect to the further biological, chemical or biochemical compatibility of the sensor electrode arrangement as a whole, it can be provided that the carrier substrate area is formed entirely or partly from a chemically inert, biologically inert material and/or material with an at most lost adsorptivity vis-à-vis proteins, biological and/or chemical active substances.
[0028] With regard to the material selection, entirely different materials can be used in the carrier substrate area:
[0029] It is conceivable to use glass, quartz and/or mica as materials for or in the carrier substrate area because, then, a particularly well-defined, well-controlled and/or planar carrier substrate area and/or surface area is then present.
[0030] However, it is advantageous if the carrier substrate area is formed entirely or partly of PMMA, PEEK, PTFE, POM, FR4 polyimide such as e.g. PI or Kapton, PEN, PET and/or a material which is transparent—in particular in the UV range—if good definition, control and/or planarity of the carrier substrate area and/or the surface area is not important. As a result of this material selection, the processing effort and the costs can be reduced.
[0031] The meaning in this respect is as follows:
PMMA polymethylmethacrylate PEEK polyetheretherketone PEN polyethylene naphthalat FR4 glass fibre-reinforced epoxy resin PI polyimide PET polyethylene terephthalate POM polyoxymethylene and PTFE polytetrafluoroethylene or Teflon
[0032] PEEK, POM and PTFE are not transparent as a rule. PTFE can usually not be bonded. However, if bonding techniques other than UV bonding are used, these materials can also be used in a meaningful manner.
[0033] With respect to as high a surface yield as possible and/or possible automation, it is, moreover, advantageous if a multiplicity, in particular of identical intermediate substrate areas or connecting substrate areas and/or corresponding biomaterial areas is formed. This plurality can be formed in a connected or in a separated form. In particular, an electrical insulation from each other offers itself in order to obtain sensor elements of the sensor electrode arrangement which are separated and insulated from each other, for example. The majority of intermediate substrate areas or connecting substrate areas and/or biomaterial areas is formed also in a form laterally arranged side by side on the carrier substrate area, for example.
[0034] An arrangement of the plurality of intermediate substrate areas or connecting substrate areas and/or corresponding biomaterial areas in a sequence or matrix form is particularly advantageous.
[0035] In a particularly advantageous manner, the use of the sensor electrode arrangement according to the present invention offers itself as sensor electrode arrangement for amperometric and/or potentiometric pharmacological effective site and/or active principle testing.
[0036] The intermediate substrate area and/or the biomaterial area or their combination can be provided in an advantageous manner as membrane biosensor electrode area or as secondary carrier of the sensor electrode arrangement.
[0037] The intermediate substrate area or the connecting substrate area and the biomaterial area can be formed respectively as a membrane biosensor electrode area or as secondary carrier with an electrically conductive and solid body-type electrode area.
[0038] With respect to the use in the area of amperometric and/or potentiometric pharmacological active site and/or active principle testing, in particular, further aspects may be essential as will be explained below.
[0039] In the case of the biocompatible or biologically compatible sensor arrangement or sensor electrode arrangement according to the invention for amperometric and/or potentiometric, pharmacological active site and/or active principle testing, a membrane biosensor electrode area is provided which, according to the meaning of the invention, is also referred to synonymously as secondary carrier. This membrane biosensor electrode area or secondary carrier exhibits an electrically conductive and solid body-type electrode area.
[0040] This is formed by the intermediate substrate area or the connecting substrate area, for example, and in particular by the actual electrode layer.
[0041] Moreover, a plurality of primary carriers is provided which are arranged in the immediate spatial vicinity of the membrane biosensor electrode area or the secondary carrier and which exhibit units which are activable to an electrical action and biological, in particular membrane proteins. In addition, an aqueous measuring medium is provided in which the primary carriers and at least part of the membrane biosensor electrode area or the secondary carrier are arranged.
[0042] According to the invention, the electrode area is formed in a manner that is electrically insulated vis-à-vis the measuring medium, the primary carriers and vis-à-vis the biological units.
[0043] According to the invention, a eukaryotic cell, a prokaryotic cell, a bacterium, a virus or components, in particular membrane fragments or associations thereof in the native form or in the modified form, in particular in the purified, microbiological form and/or form modified by molecular biology are provided as primary carrier in each case. Alternatively or additionally, a vesicle, a liposome or a micellar structure are provided as primary carrier.
[0044] An essential component of the sensor arrangement or sensor electrode arrangement according to the invention also consists of a membrane biosensor electrode area or a secondary carrier which, in the following, can also be called sensor electrode device. This sensor electrode device for amperometric and/or potentiometric, pharmacological active site and/or active principle testing itself thus exhibits at least one electrically conductive electrode area. The sensor electrode device is formed such as to be arranged in an aqueous measuring medium during operation. Moreover, the sensor electrode device is formed such that a plurality or a multiplicity of primary carriers with biological units activable into electrical action, in particular membrane proteins or such like are arranged in immediate spatial vicinity, in particular of the electrode area. According to the invention, at least the electrode area is in this respect formed like a solid body. Moreover, according to the invention, the electrode area is formed such that it is electrically insulated vis-à-vis the measuring medium to be provided and vis-à-vis the primary carriers.
[0045] It is thus a further idea of the present invention to form at least the electrode area of the sensor arrangement according to the invention and, in particular, the sensor electrode device as a solid body or in a solid body supported manner. As a result, the sensor electrode device and, in particular, the provided electrode area thereof are provided with a particularly high mechanical stability as a result of which a particularly robust operation not susceptible to interference is possible within the framework of the active site and/or active principle testing.
[0046] Only by solid body support is an activation e.g. of membrane proteins made possible by a concentration jump. This can take place, in particular, within the framework of a rapid and/or continuous solution exchange as a result of which—particularly in the case of amperometric measurements—a high signal level and consequently a high sensitivity can be achieved. As a result of the robustness due to the solid body support, easier handling and convenient incorporation are possible.
[0047] A further aspect of the present invention consists of forming the electrode area in such a way that it is formed in an electrically insulated manner vis-à-vis the measuring medium and vis-à-vis the primary carriers during operation. As a result of this measure it is possible to use the sensor electrode device as a capacitively coupled electrode, for example. This has considerable advantages particularly with regard to the signal-to-noise ratio, i.e. with regard to the accuracy of detection. Moreover, in the case of capacitive coupling, the electrode area of the sensor electrode device does not participate in any chemical conversion such as would be the case with a typical electrochemical half-cell.
[0048] The selection of the primary carriers carrying the biological units needs to be regarded as a further core aspect of the sensor arrangement according to the invention. The primary carriers may consist of eukaryotic cells, prokaryotic cells, bacteria, viruses or components, in particular membrane fragments or associations thereof respectively, namely in the native form or in a modified form, in particular in a purified form or a form modified by molecular biology and/or microbiologically. Alternatively or additionally, vesicles, liposomes or micellar structures are conceivable as primary carriers.
[0049] In the case of a particularly advantageous embodiment of the sensor arrangement according to the invention, it is anticipated that the electrode area exhibits at least one electrically conductive electrode, that an electrically insulating insulation area is provided and that the electrode concerned is electrically insulated from the measuring medium, from the primary carriers and from the biological units by the insulation area.
[0050] In this case, the electrode is formed by the intermediate substrate area or by the connecting substrate area, for example, and in particular by the actual electrode layer. The biomaterial area forms the insulation area in this case.
[0051] The electrode area also advantageously possesses at least one electrode. This can be formed, on the one hand, as such as a mechanically stable material area.
[0052] On the other hand, the electrode area can also exhibit a carrier which is formed in particular in the form of a solid body. This function is assumed by the carrier substrate area, for example. It is then possible for the electrode to be formed, respectively, as a material area or material layer on a surface area or the surface of this carrier, in particular in a continuous manner. In this respect, it is anticipated in particular for the electrode to achieve mechanical stability as a result of the solid body support provided by the carrier. This procedure has the advantage that, if necessary, high-value materials can be applied onto the carrier as a thin layer, for example, such that the possibility of a single use sensor electrode device presents itself in an economic operating respect, which device can be manufactured at affordable prices and utilised on the market. If necessary, the carrier, in particular the electrode area, can be recycled in which case, in particular, a replace insulation area, e.g. a new thiol layer, may become necessary.
[0053] Preferably, the electrode exhibits at least one metallic material or is formed of such a material. In this respect, a chemically inert noble metal, in particular, preferably gold, is advantageously used. Platinum or silver, in particular, are also conceivable.
[0054] Moreover, the use of electrically conductive metal oxides for or in the intermediate substrate area or the connecting substrate area, e.g. of ITO or indium tin oxide, is conceivable. From or with this class of material, counter-electrodes, which may need to be provided, may be manufactured.
[0055] The carrier for accepting the electrode consequently advantageously exhibits an electrically insulating material or is formed of such a material. Moreover, or alternatively, it is advantageous for the material of the carrier to be essentially chemically inert. Advantageously, glass or the like offers itself as a material. In this respect, the shape may that of a panel or such like. The chemical inertness prevents both a modification of the carrier and a contamination of the measuring medium during the measuring process. As a result of the selection of an electrically insulating carrier, it is guaranteed that all measuring signals originate essentially from the area of the electrode.
[0056] A possible arrangement of the sensor electrode device is obtained if the electrode is essentially formed as material layer deposited on the surface of the carrier. It can also be a vapour deposited or sputtered material layer. The material layer for the formation of the electrode has a layer thickness of approximately 10 nm to 200 nm, for example.
[0057] Between the material layer for the electrode and the surface of the carrier, an adhesive layer may, if necessary, be of advantage. On applying a gold electrode onto glass, in particular, an adhesive layer of chromium or such like present in between is of advantage. Advantageously, the adhesive layer has a relatively low layer thickness, preferably of approximately 5 nm.
[0058] To form the capacitive electrode and the insulation of the electrode area from the measuring medium and/or from the primary carriers, which is necessary for this purpose, at least one insulating area or biomaterial area is thus preferably formed as a result of which the electrode area, in particular the electrode, is essentially electrically insulatable in operation, in particular in areas thereof which are provided for mechanical contact with the measuring medium and/or the primary carriers during operation.
[0059] In a further preferred embodiment of the sensor arrangement or sensor electrode arrangement according to the invention, the insulation area or biomaterial area is formed in the form of layers. In this respect, the insulation area or biomaterial area consists at least partly of a sequence of monolayers, the monolayers being formed as spontaneously self-organising layers.
[0060] In this respect, it is advantageous for a layer of an organic thio compound to be provided as a sub-layer of the insulation area or biomaterial area or as a bottom most area, or an area facing towards the electrode, of the insulation area or the biomaterial area, with a view to the electrical properties and the electrical insulation, preferably of a long-chain alkane thiol, in particular of octadecane thiol.
[0061] Moreover a layer of an amphiphilic organic compound, in particular of a lipid, is provided as top layer of the insulation area or biomaterial area, as an uppermost area facing away from the electrode or surface area of the insulation area.
[0062] It can thus be advantageous to form the insulation area or biomaterial area at least partly in layer form, in particular in multilayer form. In this way, the insulation effect is strengthened and the manufacture simplified. In order to obtain as high a rate of attached and/or arranged primary carriers as possible in the area of the sensor electrode device, it is anticipated according to a preferred embodiment of the sensor electrode device according to the invention that at least the surface area of the insulation area is formed in such a matched manner that an attachment and/or arrangement of primary carriers on the surface area of the insulation area is promoted, in particular in a manner compatible with the surface of the primary carriers. This means that, depending on the surface properties of the primary carrier, the surface area of the insulation area of the sensor electrode device be formed in a correspondingly adjusted manner such that the primary carriers attach themselves in a favoured manner to the surface area of the insulation area and remain there.
[0063] With respect to a particularly marked capacitive coupling of the sensor electrode device during measuring operation, it is therefore anticipated that the insulation area is formed at least partly as a single layer, monolayer and/or as a sequence thereof. In this case, the specific area-related electric capacitance of the electrode boundary layer is particularly high. The arrangement and formation of the sensor arrangement according to the invention is particularly simple if the layer or layers of the insulation area are formed as spontaneously self-organising layers or as self-assembling layers. In this respect, the tendency and the endeavours of certain essentially liquid starting materials or those dissolved in the liquid state to form, on a surface, under the influence of the interaction with the structure of the surface, spontaneously and in a self-organising manner, an ordered and/or layer-type structure which, under certain circumstances and in the case of certain classes of substances leads to the formation of particularly thin and, if necessary, single-layer layers or monolayers, in particular of molecules, are exploited in an advantageous manner.
[0064] In the case of the use of, according to the invention, organic thio compounds, in particular of alkane thiols, use is made of the fact that, on certain noble metal surfaces, e.g. gold, silver and platinum, it is possible to form, from an organic solution which contains the corresponding thio compound in solution, a covalently bonded monolayer on the electrode surface as a result of a specific chemical interaction of the thio group with the surface atoms of the noble metal electrode, which monolayer is capable of forming a hexagonal dense package in the case of a corresponding geometry of the thio compound, as a result of which a particularly low residual conductivity of the noble metal surface is achievable with respect to the measuring medium to be provided.
[0065] Correspondingly, it is possible when using metal oxides in the area of exposed surface areas of the intermediate substrate area or the connecting substrate area, in particular of indium tin oxide, to make use of a correspondingly specific siloxane chemistry for the formation of a covalently bonded sub-layer of the insulation area or the biomaterial area, in which, as top layer or as uppermost layer and area facing away from the electrode or surface area of the insulation area or biomaterial area, a layer of an amphiphilic organic compound, in particular a lipid and/or the like is provided.
[0066] As a result of the procedure in which, as top layer or as uppermost area facing away from the electrode or surface area of the insulation area or biomaterial area, a layer of an amphiphilic organic compound, in particular a lipid and/or the like is provided, a particularly well-defined arrangement and structurisation of the surface of the insulation area or biomaterial area is forcefully obtained.
[0067] The amphiphilic organic compounds possess at least one area of polar formation such that a certain partial solubility arises in the measuring medium which, in particular, is of an aqueous nature. On the other hand, amphiphilic organic compounds possess a non-polar or hydrophobic area whose arrangement in an aqueous measuring medium is less preferred from the energy point of view. As a result of this phenomenon, a layer structure is preferably formed in the case of which the polar or water-soluble areas of the amphiphilic compounds are allocated to the aqueous measuring medium whereas the non-polar or hydrophobic areas of the amphiphilic organic compounds are arranged facing away from the aqueous measuring medium. Consequently, a monolayer can be formed which forms, in particular, the surface area of the electrode area. This is preferably done in combination with an alkane thiol monolayer as sub-layer such that, at least partly, a double layer of two monolayers is formed as insulation area or biomaterial area.
[0068] The sequence of two monolayers thus formed has certain structural similarities to certain membrane structures which are known from biological systems such that a certain membrane structure can be allocated to the sequence of two monolayers thus formed—namely the alkane thiol monolayer facing towards the electrode and the lipid monolayer arranged on top. As a result of the basic solid body carrier, this membrane structure is also referred to as solid body supported membrane SSM (SSM: solid supported membrane). This SSM membrane structure has particularly advantageous properties with respect to the arrangement and characteristic property of the sensor electrode device according to the invention, as a capacitively coupled electrode.
[0069] The area which is defined by the electrode-insulating and/or covering layer of the insulation area or biomaterial area, in particular, exhibits the membrane structure just described in an advantageous manner. In this respect, it is also advantageous that this membrane structure or SSM has at least in part a specific electric conductivity of approximately G m ≈1-100 nS/cm 2 . Moreover, a specific electric capacitance of approximately C m ≈10-1000 nF/cm 2 is advantageously present. Finally a surface for the membrane structure of approximately A≈0.1-50 mm 2 is provided alternatively or as a supplement.
[0070] The high specific capacitance Cm is of particular advantage with respect to an amperometric active principle test to be carried out, in the case of which initiated electrical actions of the essentially biological units are measured as electric currents, namely as displacement currents or capacitive currents.
[0071] With a view to the signal-to-noise ratio, a corresponding sealant resistance in the area of a few nanosiemens is of particular advantage.
[0072] According to another embodiment of the sensor arrangement according to the invention, this can also be achieved by applying a Teflon layer, e.g. directly onto the metal electrode. Such a procedure is entirely sufficient for potentiometric active principle testing, for example, since, in this case, it is not a high electrical capacitance which is important but a high sealing resistance because of the voltage measurements.
[0073] Particularly simple geometric circumstances arise, in particular with a view to the reproducibility of the measured results, if the carrier, the electrode and/or the insulation area and/or its surface or boundary surface areas are formed at least partly in an essentially planar manner, in particular also at the microscopic level or scale. The planarity guarantees that certain field strength effects at the edges or tips which may lead to the breakthrough of the sealing resistance, do not arise. Moreover, with a view to the exchange, in operation, of the measuring medium to be provided, the advantage of a homogeneous boundary surface distribution arises. Any possible protuberances or cavities would lead to concentration inhomogeneities at the boundary surface between the insulation area and the measuring medium, which inhomogeneities could possibly have a negative influence on the results of detection or measurement achieved. The planarity, in particular of the metallic boundary surfaces, can be guaranteed by corresponding manufacturing processes, e.g. by epitactic growth, annealing or such like.
[0074] For external contacting of the sensor arrangement, e.g. with an external measuring circuit or the like, a contact area is provided, a corresponding insulation to avoid other short circuits, in particular with respect to the measuring medium, being formed.
[0075] In particular with a view to a high rate of throughput in the case of active site and/or active principle tests to be carried out correspondingly, it is particularly advantageous if the sensor arrangement according to the invention is formed in such a way that, at least in operation, it exhibits essentially constant mechanical, electrical and/or structural properties vis-à-vis liquid streams with a high flow rate, preferably in the region of approximately v≈0.1-2 m/s, in particular in the region of the membrane structure and/or especially with a view to the attachment and/or arrangement of primary carriers. This required and advantageous consistency of the mechanical, electrical and/or structural properties of the sensor arrangement according to the invention and, in particular, the membrane structure provided therein is obtained inherently as a result of the above-mentioned measures for the formation of the electrode and the insulation layer covering the electrode, in particular in the form of self-assembling monolayers of an alkane thiol on gold with a corresponding monolayer of lipid in an aqueous medium.
[0076] Advantageously, the sensor arrangement according to the invention is used with the sensor electrode device described, in a process for amperometric and/or potentiometric, pharmacological active site and/or active principle testing and in a device for carrying out such a process.
[0077] In the case of the sensor arrangement according to the invention, a eukaryotic cell, a prokaryotic cell, organelles thereof, a bacterial unit, a viral unit and/or such like and/or components, fragments, in particular membrane fragments of such like and/or associations thereof in an essentially native and/or modified, in particular purified form or form modified microbiologically and/or by molecular biology are provided as primary carriers respectively.
[0078] It is thus conceivable in principle that insulated and whole cells are used as primary carriers of corresponding biological units which can be activated to an electrical action, irrespective of whether these are of plant or animal origin. Thus, an examination of entire heart cells, for example, is possible and conceivable. On the other hand, the examination of plant cells, for example algae cells or other unicellular organisms, can also be considered. In addition, certain bacteria or viruses can be examined as a whole. Moreover, it is conceivable to use components or fragments of cells, bacteria or viruses as primary carriers as a result of specific microbiological or biochemical measures. Also, it is conceivable to use associations of cells, bacteria or such like as primary carriers and to connect these to the corresponding sensor electrode device for the formation of a sensor arrangement according to the invention.
[0079] Moreover, the possibility exists according to the invention of using the suggested primary carriers in their native form or in a modified form. In this respect, eukaryotic cells, prokaryotic cells or bacteria, for example can be used which have been modified by corresponding purification, microbiological and/or molecular biology processes in order to preferably form specific proteins with certain desired properties, for example.
[0080] Apart from the primary carriers already available in their natural form in the form of cells, bacteria and the like, it is also conceivable to produce artificial primary carriers in the form of vesicles, liposomes, micellar structures and/or the like, for example. If necessary, these are then provided and/or enriched with corresponding biological units which can be activated to electrical action. Corresponding processes for the reconstitution of membrane proteins or such like in vesicles or liposomes are known and can be exploited here in an advantageous manner in order to create particularly advantageous embodiments of the sensor arrangement according to the invention.
[0081] Suitable as essentially biological units are all units which can be triggered into an at least partly electrically produced action. Such biological units are conceivable in particular which are activable to perform an at least partial electrogenic and/or electrophoretic charge carrier transport and/or an at least partial electrogenic or electrophoretic charge carrier movement and which represent biological, chemical and biochemical units. These are in particular transport units which move charge carriers upon their activation. Components, fragments and/or associations of such units, in particular transport units, are also conceivable.
[0082] Membrane proteins, in particular ion pumps, ion channels, transporters, receptors and/or such like offer themselves in particular as biological units. With respect to many of these biological units, findings and/or assumptions exist to the effect that certain processes are associated with at least one electrogenic partial step. These electrogenic partial steps can be associated with an actual substance transport such as in the case of a channel, an ion pump or certain transporters, for example. However, biological units, in particular membrane proteins, are also known whose electrical activity is not connected with a net material transport but rather with a, if necessary reversible, charge displacement within the framework of a conformation change or bonding or such like. Such electrical activities, too, are measurable, in principle, according to the invention as short-term displacement currents and/or potential changes.
[0083] The biological units, in particular the membrane proteins, can be provided in essentially their native form and/or in a modified, in particular purified form or a form modified microbiologically and/or by molecular biology, respectively. On the one hand, certain native properties, can be tested and pharmacologically investigated in the organism of existing proteins, for example. On the other hand, modifications initiated by molecular biology or gene technology also offer themselves for analysing certain aspects, e.g. the transportation or the pharmacological mode of action of an active principle.
[0084] It is particularly advantageous that primary carriers of an essentially uniform type of primary carrier are provided in each case. This is of importance with regard to as unambiguous as possible as evidence and analysis of an active substance test and relates to the geometric, physical, chemical, biological and molecular biological properties of the primary carrier.
[0085] The same also applies to the biological units provided for the primary carrier, in particular to the membrane proteins or such like. In this case, biological units of an essentially uniform type are provided in each case, in particular with respect to their geometrical, physical, chemical, biological and molecular biological properties. In addition, the biological units should advantageously be approximately uniform with respect to their orientation and/or with respect to their activatibility in relation to the primary carrier concerned.
[0086] To achieve as high a signal quality as possible, it is advantageous for the surfaces of the primary carrier and/or the secondary carrier to be formed in such a way that an attachment and/or arrangement of the primary carriers on the secondary carrier is promoted. In this way, a particularly high number of attached primary carriers and/or a particularly close contact of the primary carriers to the secondary carrier is obtained, on the one hand, as a result of which the electrical connection and consequently the signal-to-noise ratio are increased.
[0087] The attachment can be controlled e.g. via the so-called lipid-lipid interaction between the primary carrier, e.g. vesicle, and the secondary carrier, e.g. lipid thiol SSM. On the other hand, a covalent bond of the primary carrier to the surface of the secondary carrier is conceivable, e.g. in the form of a biotin-streptavidin scheme or according to the meaning of His-Tag coupling.
[0088] In this connection, it is particularly advantageous if the surfaces of the primary carriers and of the secondary carrier are formed with an opposite polarity to each other. This promotes the rate of attachment of the primary carriers to the secondary carrier and the strength of the contact between them.
[0089] It is particularly advantageous if vesicles or liposomes with essentially the same effect and/or of the same type, preferably of a lipid, are provided as primary carriers in and/or on the membrane of which units of essentially one type of membrane protein are embedded and/or attached in preferably essentially an oriented form.
[0090] The sensor arrangement according to the invention is advantageously used in a process for amperometric and/or potentiometric, in particular pharmacological active site and/or active principle testing and/or in a device for carrying out such a process.
[0091] According to a further aspect of the present invention, a process for manufacturing a biologically compatible or biocompatible sensor electrode arrangement, in particular a sensor electrode arrangement for amperometric and/or potentiometric, pharmacological active site and/or active principle testing is created.
[0092] In the manufacturing process according to the invention, at least one carrier substrate area with a top side with a surface area or with a top side surface area is formed. Moreover, at least one intermediate substrate area or a connecting substrate area is formed on the surface area or the top side surface area of the carrier substrate area or a part thereof, in particular in a structured manner and with a top side facing away from the carrier substrate area with a surface area or with a top side surface area. Moreover, a biomaterial area is formed on the top side surface area of the intermediate substrate area or the connecting substrate area or a part thereof, in particular in a structured manner, with at least one biologically compatible or biocompatible material component. According to the invention, the carrier substrate area with the intermediate substrate area or the connecting substrate area thereon or the intermediate substrate area or the connecting substrate area as such and/or a part thereof in each case are formed in the form or the manner of a wafer element or a printed circuit. Alternatively or additionally, it is anticipated that the carrier substrate area with the intermediate substrate area and the connecting substrate area thereon or the intermediate substrate area or the connecting substrate area as such and/or a part thereof in each case are formed as a or with a photolithographically processed structure or as a or with a photographically processed element, as a or with a structure processed by being bonded on or laminated on or as an or with an element processed by being bonded on or laminated on, as a or with a structure processed micromechanically and/or by laser ablation or as an or with an element processed micromechanically and/or by laser ablation and/or a structure processed by printing or as an or with an element processed by printing. This is provided in particular on the carrier substrate area in each case.
[0093] Basic aspects of the manufacturing process according to the invention consequently need to be seen in the fact that a carrier substrate area, an intermediate substrate area or a connecting substrate area thereon and a biomaterial area are provided on the surface area of the intermediate substrate area or the connecting substrate area. In this connection, it is a further aspect that the carrier substrate area with the intermediate substrate area or the connecting substrate area thereon or the intermediate substrate area or the connecting substrate area as such and/or a part thereof in each case are processed in a manner possible for wafers or printed circuits in order to achieve a particularly reliable and cost-effective manufacture, in particular in mass manufacture.
[0094] The further manufacturing modes with a view to the provision of photolithographically processed structures or elements, bonded-on and/or laminated-on processed structures or elements, structures or elements processed micromechanically and/or by laser ablation and/or structures or elements processed by printing need to be additionally or alternatively provided.
[0095] The ablation and/or laser ablation takes place, if necessary, with mask support.
[0096] The individual process steps of the manufacturing process according to the invention and/or their modifications are also carried out in line with the structural measures described above.
[0097] Thus, it is anticipated according to a preferred embodiment of the manufacturing process according to the invention that the carrier substrate area is formed with a chemically inert, biologically inert and/or essentially electrically insulated material or of such a material.
[0098] Moreover, it is anticipated alternatively or additionally that the carrier substrate area is formed with a mechanically flexible material or of such a material, in particular in the form or in the manner of a film.
[0099] With regard to the structurisation of the biocompatible material arrangement as sensor electrode arrangement, it is additionally or alternatively provided in the case of an another embodiment of the manufacturing process according to the invention of a sensor electrode arrangement that, for the intermediate substrate area or for the connecting substrate area, a layer of an electrically conductive metal oxide, for example ITO or indium tin oxide, is formed.
[0100] In the case of another embodiment of the manufacturing process according to the invention, it is anticipated that, for the intermediate substrate area or for the connecting substrate area, a metallic layer structure is formed on the top side surface or the top side surface area of the carrier substrate area.
[0101] In this connection, it may be anticipated in an advantageous manner that the layer structure for the intermediate substrate area or for the connecting substrate area is formed with at least one or of a primary metal area arranged bottom most, a subsequent auxiliary layer and an actual electrode layer arranged top most.
[0102] In this connection, the primary metal layer or the primary metal area is formed as an alloy barrier and/or diffusion barrier.
[0103] It is moreover preferred that the primary metal area is formed with or of copper.
[0104] Moreover, it is preferred that the primary metal area is formed photolithographically. Alternatively or additionally, the possibility offers itself to process by bonding on, laminating on, ablation and/or printing on.
[0105] The auxiliary layer is advantageously formed of nickel or containing nickel.
[0106] According to a further alternative embodiment of the manufacturing process according to the invention, the actual electrode material arranged top most or the actual electrode layer arranged top most is formed with or of noble metal, preferably with or of gold.
[0107] It is particularly preferred that the auxiliary layer and/or the actual electrode layer arranged top most is formed by electrodeposition.
[0108] Alternatively or additionally, micromechanical processing and/or laser ablation can be used.
[0109] Particularly advantageous properties of the sensor electrode arrangement to be manufactured are obtained if, according to a preferred embodiment of the manufacturing process, the carrier substrate area is formed entirely or partly of a chemically inert, biologically inert material and/or a material that is at most slightly absorptive vis-à-vis proteins, biological and/or chemical active principles.
[0110] In the case of a further advantageous embodiment of the manufacturing process according to the invention it is anticipated that the carrier substrate area is formed entirely or partly of PMMA, PTFE, POM, FR4, polyimide such as e.g. PI or Kapton, PEN, PET and/or of a material that is transparent—particularly in the UV range.
[0111] For further flexibilisation and enlargement of the area of use of the product to be manufactured according to the meaning of the sensor electrode arrangement to be manufactured, it is anticipated in the case of a further advantageous development of the manufacturing process according to the invention that a plurality—in particular of homogeneous—intermediate substrate areas or connecting substrate areas and/or biomaterial areas is formed. These may be formed in a connecting or in a separate form, in particular with a view to their electrical connection and/or electrical insulation with and/or from each other. This takes place, in particular, in a laterally separated manner.
[0112] In an advantageous manner, the plurality of intermediate substrate areas or connecting substrate areas and/or biomaterial areas is arranged in series or in matrix form.
[0113] According to a further advantageous embodiment of the manufacturing process according to the invention, the sensor electrode arrangement is formed as a sensor electrode arrangement for amperometric and/or potentiometric, pharmacological active site and/or active principle testing.
[0114] In this connection, the intermediate substrate area and/or the biomaterial area are provided in each case as membrane sensor electrode area or as secondary carrier of the sensor electrode arrangement.
[0115] In the case of another embodiment of the process according to the invention, the intermediate substrate area or the connecting substrate area and the biomaterial area are formed, in each case, as a membrane biosensor electrode area or as a secondary carrier with an electrically conductive and solid body-type electrode area.
[0116] In this connection, a plurality of primary carriers is provided in the immediate spatial vicinity of the secondary carriers or the secondary carrier. In this case, the primary carriers contain, biological units activable into electrical action, in particular membrane proteins.
[0117] According to the invention, a eukaryotic cell, a prokaryotic cell, a bacterium, a virus or components, in particular membrane fragments or associations thereof in the native form or in the modified form, in particular in the purified, microbiological form and/or form modified by molecular biology are provided as primary carrier in each case. Alternatively or additionally, a vesicle, a liposome or a cellular structure are provided as primary carrier.
[0118] Moreover, it may be anticipated that the intermediate substrate area or the connecting substrate area is provided as at least one electrically conductive electrode of the electrode area, that the biomaterial area is provided as an electrically insulated insulation area and that, in operation, the electrode concerned is electrically insulated by the biomaterial area or the insulation area from a measuring medium, from the primary carriers and from the biological units.
[0119] According to a further embodiment of the process according to the invention, it is anticipated that the biomaterial area or insulation area is formed in layers, that the insulation area is formed at least partly of a sequence of monolayers and/or that the monolayers are formed as spontaneously self-organising layers.
[0120] In the case of another embodiment of the process according to the invention, it is anticipated that, as a sub-layer of the biomaterial area or the insulation area, a layer of an organic thio compound is provided as a bottom most area of the insulation area facing towards the electrode, preferably of a long-chain alkane thiol, in particular of octadecane thiol, and that, as top layer of the biomaterial area or the insulation area, a layer of an amphiphilic organic compound, in particular of a lipid, is provided as uppermost area facing away from the electrode or surface area of the insulation area.
[0121] In the case of a further advantageous embodiment of the manufacturing process according to the invention, it is anticipated that the area of the biomaterial area or the insulation area insulating and covering the electrode is formed with a membrane structure with a surface of approximately A≈0.1-50 mm 2 and with a specific electric conductivity of approximately G m ≈1-100 nS/cm 2 and/or with a specific capacitance of approximately C m ≈10-1000 nF/cm 2 .
[0122] According to a further preferred embodiment of the manufacturing process according to the invention, it is anticipated that a biological unit is provided which is formed to be activable to an electrogenic charge carrier movement, in particular to an electrogenic charge carrier transport.
[0123] Additionally or alternatively, it is anticipated that a membrane protein, in particular an ion pump, an ion channel, a transporter or a receptor or a component or an association thereof is provided as biological unit in each case.
[0124] Moreover, it is preferred alternatively or additionally that the biological unit is provided in native form or in a modified form, in particular in a purified, microbiologically modified form and/or a form modified by molecular biology.
[0125] In a further advantageous development of the manufacturing process according to the invention, it is anticipated that the surface of the primary carriers and the surface of the secondary carriers are formed with opposite polarity or oppositely charged to each other and/or that, between the surface of the primary carriers and the surface of the secondary carrier, a connection in the manner of a chemical bond is formed, in particular via a His-Tag coupling or a streptavidin-biotin coupling or the like.
[0126] These and other aspects of the present invention result, in other words, also from the following remarks:
[0127] The invention relates not only to corresponding structures but also to a process for the manufacture of electrically insulating, extremely thin layers as biocompatible areas or material areas, in particular on printed circuit boards or the like and to their use as sensor elements, in particular for single use.
[0128] In the field of bioanalysis, it is desirable in certain cases to have biocompatible surfaces available which are suitable for the absorptive attachment of biological membranes, membrane fragments or of artificial lipid double layers. The task, on which the invention described herein is based, consisted of manufacturing such surfaces in as cost-effective a manner as possible without suffering restrictions in functionality.
[0129] Methods are known which operate on the basis of optical measured values on biocompatible layers, so-called biacore measurements, for example, according to the principle of surface plasmon resonance or measurements of the load increase change using the quartz microbalance. In other cases, electrical properties of the attached, often protein-containing vesicles, cells or membrane fragments are to be detected.
[0130] Frequently, substrates or carrier substrate areas of mica, glass or quartz can be used which are coated e.g. with gold, by thin layer technique.
[0131] Occasionally, the selection of the substrate needs to be made on the basis of the specific properties of the substrate, e.g. glass, because of its transmittance in the area of visible light and because of its refractive index, quartz as a result of its ability to be induced to oscillation in the condenser field. Occasionally, glass is used because of its chemical inertness and the possibility of lithographic structuring of the gold layer down into the microstructure region.
[0132] Providing mica, glass and/or quartz with the intermediate substrate area or connecting substrate area by epitaxial growth, by vapour deposition and/or sputtering, for example, is meaningful and anticipated according to the invention in those cases where the controllability, high definition, high value and/or planarity of the intermediate substrate area or connecting substrate area and/or the corresponding surface areas are of importance.
[0133] It is also conceivable that areas can be produced on gold surfaces which are capable of providing specific bonding for target molecules.
[0134] The manufacture of structured biocompatible areas on gold surfaces which, in turn, have been applied onto glass substrates is complicated and costly under certain circumstances. Moreover, glass is fragile and may form, under certain circumstances, sharp edges capable of causing injuries.
[0135] These properties lead to the replacement according to the invention of glass substrates, mica or quartz as carrier for biocompatible areas according to the meaning of the invention by other materials and/or coating techniques other than epitaxial growing, vapour deposition and/or sputtering.
[0136] The use of a self-organising monolayer, a self-assembled monolayer or an SAM does not lead to the desired or necessary electrical properties and only partly to the ability of the surface to adsorb vesicles, cells or membrane fragments.
[0137] It is a core idea of this invention to produce, on printed circuit boards or such like producible cost-effectively in very large numbers, for example, biocompatible areas which provide a very low electric conductivity between the actual electrode or intermediate substrate and the surroundings and exhibit suitable adsorption properties with respect to cells, cell membrane fragments, liposomes or such like.
[0138] The structurisation of the printed circuit boards or such like takes place by selective or structured coating of a primary metal layer, e.g. a copper layer, for example, by subsequently selectively removing the primary metal layer, e.g. by wet-chemical etching, and by subsequent finishing, e.g. by gold plating.
[0139] These techniques permit the manufacture of very large numbers of items, the costs being lower by a multiple than those in the case of glass substrates. Moreover, biocompatible areas serving as biosensor can be manufactured in the immediate spatial vicinity to amplifier devices on wafers such that noise and interference can be considerably reduced. The substrates used for the manufacture are highly stable and, optionally, do not have sharp edges. They are therefore highly suitable for manufacturing disposables.
[0140] A copper-coated printed circuit board—e.g. with 17 μm copper—, for example, is coated with photoresist. A layout is transferred onto the photoresist by light exposure. The photoresist is developed and removed specifically in the areas not exposed to light, the copper layer being exposed in those areas. The copper layer is removed at the exposed sites. The remaining resist residues are also removed. Nickel, for example, is electrodeposited onto the free copper structures. Gold, for example, is electrodeposited onto the nickel layer thus obtained.
[0141] An alkane thiol monolayer is produced on the gold layer as self-assembled monolayer or SAM. By adding lipid-containing solution, a hybrid lipid layer is produced on the SAM in a manner analogous to a lipid double layer. This hybrid lipid layer permits the stable adsorption e.g. of membrane fragments of biological membranes, cell fragments, vesicles and liposomes.
[0142] By integrating the printed circuit boards or the like into an electric amplifier circuit and by integrating the biocompatible area into a flow cell and by introducing an Ag/AgCl reference electrode into the fluid-coupled system and by attaching membrane fragments with electrogenic membrane proteins, the modified printed circuit boards can be used as biosensors.
[0143] Further aspects of the present invention arise as follows:
[0144] Frequently, glass and/or a complicated technical process are used in order to obtain thin, very high quality intermediate substrate areas, connecting substrate areas and/or actual electrode layers according to the meaning of the invention, in particular gold layers, with it. The basic idea has been that a slightly rough surface is particularly advantageous.
[0145] This process may be uneconomical. As an alternative, it is thus possible to use intermediate substrate areas, connecting substrate areas and/or actual electrode layers, i.e. gold layers, for example, and corresponding surface areas of comparatively extremely poor quality with respect to visible granularity under the light microscope, layer thickness of several micrometers, beads, scratches etc, for example.
[0146] However, it has been found that essential characteristics of the membrane biosensor electrode area, i.e. the SSM, are retained such that the materials mica, glass, quartz and/or the application or structurisation by epitaxial growing, by vapour deposition and/or by sputtering are not necessarily required.
[0147] Consequently, fields of application for these comparatively low value but also cheap electrodes thus specifically arise in an advantageous manner.
[0148] Consequently, comprehensive extensions of the comparatively complex arrangements and the corresponding manufacturing processes thus arise according to the invention.
[0149] For this reason, too, the possibility offers itself to structurise gold-vapour deposition treated films, for example, consisting of polyimid or PEN, for example, by laser ablation, the laser beam being passed through a mask. The film may be drawn from a roll and structured in a continuous process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0150] In the following, the present invention is explained in further detail by way of a diagrammatic representation based on preferred practical examples.
[0151] FIG. 1 shows a diagrammatic and sectional side view of an embodiment of the biocompatible sensor electrode arrangement according to the invention.
[0152] FIGS. 2A , B show a diagrammatic top view and/or a sectional side view of another embodiment of the biocompatible sensor electrode arrangement according to the invention.
[0153] FIG. 3 shows a diagrammatic top view of a further embodiment of the biocompatible sensor electrode arrangement according to the invention with a plurality of individual electrodes.
[0154] FIG. 4 shows a diagrammatic and partial sectional side view of another embodiment of the biocompatible sensor electrode arrangement according to the invention with a vesicle as primary carrier and its use in a measuring device.
[0155] FIG. 5 shows a further embodiment of the biocompatible sensor electrode arrangement according to the invention with a membrane fragment as a primary carrier.
DETAILED DESCRIPTION OF THE INVENTION
[0156] In the following the same references indicate the same, identical or identically acting structures or elements. A detailed description will therefore not be repeated each time they occur.
[0157] FIG. 1 shows a diagrammatic and sectional side view of a first embodiment of the biocompatible sensor electrode arrangement 1 according to the invention.
[0158] This first embodiment of the biocompatible sensor electrode arrangement 1 according to the invention exhibits a carrier substrate area 22 or a carrier substrate 22 with a top side surface area 22 a on which the connecting intermediate substrate area 26 or the connecting substrate area 26 is provided in the form of a layered metal structure, namely with a primary metal area 26 - 1 , of copper in this case, an auxiliary layer 26 - 2 , e.g. of nickel in this case, which serves as diffusion barrier and alloy formation barrier, as well as an actual electrode layer 26 - 3 , of gold in this case.
[0159] By a specific chemical interaction with the actual electrode layer 26 - 3 , a biomaterial layer 24 or a biomaterial area 24 is immobilised on the top side surface area 26 a of the connecting substrate area 26 . This biomaterial area 24 serves as insulation area 24 for the sensor electrode arrangement 1 according to the invention and consists of a layered sequence of self-organising monolayers 24 a and 24 b , namely of a sub-layer arranged bottom most in the form of an alkane thiol monolayer 24 b which is connected via the specific thiol gold interaction or SH—Au interaction, and a lipid monolayer 24 a provided uppermost. By means of this arrangement, a membrane biosensor electrode device M or 20 with a solid body-supported membrane SSM is formed.
[0160] FIGS. 2A and 2B show a diagrammatic top view and/or a diagrammatic and sectional side view of another embodiment of the biocompatible sensor electrode arrangement 1 according to the invention. In this case, a processed counter-electrode device 46 is also shown in the top view of FIG. 2A , which device, however, was left out from the side view of FIG. 2B . This counter-electrode 46 can also consist of ITO or indium tin oxide and assume alternative embodiments.
[0161] FIG. 3 shows, by way of a diagrammatic top view, an embodiment of the sensor electrode arrangement 1 according to the invention on which six individual electrodes 26 with corresponding supply leads 29 are formed on the upper surface 22 a of the carrier substrate 22 . The individual electrodes 26 with their corresponding terminal leads 29 are formed in an essentially identical manner, at least insofar as the manufacturing tolerances allow.
[0162] All characteristic properties relating to the mesoscopic or microscope structure of the surface of the membrane biosensor electrode area M, the secondary carrier 20 and, in particular, the respective allocated electrodes 26 can also be seen in the representation of the following FIGS. 4 and 5 . All the characteristic properties illustrated therein are applicable in any random combination to the structures described above in FIG. 1 to 3 .
[0163] FIG. 4 shows a diagrammatic and partly sectional side view of a further embodiment of the sensor arrangement 1 according to the invention and a corresponding device for amperometric and/or potentiometric pharmacological active principle testing.
[0164] A measuring chamber 50 in the form of an essentially closed vessel forms, together with an exchanger/mixing device 60 in the form of a perfuser system or a pump facility, for example, a closed liquid circuit. Communication of the liquid serving as measuring medium 30 is effected via corresponding feed and discharge devices 51 and/or 52 . The measuring medium 30 can be an aqueous electrolyte solution in this case which exhibits certain ion moieties, a given temperature, a specific pH etc. Moreover, specific substrate substances S and/or specific active principles W are, if necessary, contained in the measuring medium 30 or they are added in later process steps through the exchange/mixing device 60 .
[0165] In the measuring area 50 , a sensor arrangement 1 according to the invention is provided. The sensor arrangement 1 consists of primary carriers 10 which are attached to the surface area 24 a of the sensor electrode device 20 serving as secondary carrier.
[0166] In the practical example shown in FIG. 4 in diagrammatic form not true to scale, only a single primary carrier 10 is shown. This consists of a lipid vesicle or liposome in the form of a lipid double layer or lipid membrane 11 formed as an essentially hollow closed sphere. In this lipid double layer 11 of the vesicle serving as primary carrier 10 , a membrane protein is embedded in a manner penetrating through the membrane as essentially biological unit 12 .
[0167] By converting a substrate S present in the measuring medium 30 into a converted substrate S′, certain processes are initiated in the membrane protein 12 which, in the case shown in FIG. 1 , leads to a substance transport of a species Q from the extra-vesicular side or outside 10 a of the vesicle 10 to the intravesicular side or inside 10 b of the vesicle 10 . If the species Q has an electric charge, the transportation of the species Q from side 10 a to side 10 b leads to a net charge transportation which corresponds to an electric current from the outside 10 a of the vesicle 10 to the inside 10 b of the vesicle 10 .
[0168] Into each vesicle 10 , a multiplicity of essentially identical membrane protein molecules 12 are incorporated in essentially the same orientation into membrane 11 of the vesicle 10 as a rule and on the one hand. If these are essentially simultaneously activated—e.g. by a concentration jump, initiated by mixing, in the concentration of the substrate S of a non-activating measuring medium N, 30 without substrate S to an activating measuring medium A, 30 with substrate S—this leads to a measurable electric current.
[0169] This charge carrier transportation is measurable because a multiplicity of primary carriers 10 or vesicles are attached to the surface 24 a of the sensor electrode device 20 such that, on activation of a multiplicity of protein molecules 12 in a multiplicity of vesicles in front of the surface 24 a of the sensor electrode device 20 , a spatial charge of a certain polarity is formed. This spatial charge then acts onto the electrode 26 which, in the case shown in FIG. 1 , is vapour deposited onto a carrier 22 of glass in the form of a gold layer and covered by a double layer, serving as insulation area 24 , of a bottom layer 24 b and a top layer 24 a serving as surface and electrically insulated vis-à-vis the measuring medium 30 .
[0170] The surface or upper layer 24 a of the insulation area 24 is a lipid monolayer, for example, which is compatible with the lipid double layer 11 of the vesicle 10 which monolayer is formed by means of a self-assembly process on an alkane thiol monolayer forming the bottom layer 24 b in such a way that the sequence of the layers 24 b and 24 a , namely the sequence of an alkane thiol monolayer and a lipid monolayer, forms a membrane structure SSM as electrode 26 on a gold substrate formed in the manner of a solid body, which membrane structure is also referred to as solid supported membrane (SSM).
[0171] The sensor arrangement 1 and, in particular, the sensor electrode device 20 is connected to a data acquisition/control device 40 via a connecting line 48 i . This device is equipped with a measuring device 44 in which an electric current I(t) or an electric voltage U(t) can be measured as a function of time. Moreover, an amplifier device 42 is anticipated in which the measuring signals are filtered and/or amplified. Via a control line 48 s , the active principle testing is controlled by controlling the exchange/measuring device 60 . Via a further line 48 o , the electric circuit is closed by a counter-electrode 46 , e.g. in the form of a Pt/Pt electrode or by an Ag/AgCl electrode. Insulations 28 , 27 and 47 prevent short circuits of the SSM and/or the counter-electrode 46 vis-à-vis the measuring medium 30 .
[0172] FIG. 5 shows a diagrammatic and partly sectional side view of an embodiment of the sensor arrangement 1 according to the invention in the case of which a membrane fragment 10 is provided as primary carrier 10 instead of a vesicle or liposome, into which fragment a membrane protein is embedded as biological unit 12 in an oriented manner. With respect to the embodiment of FIG. 5 , it should be noted that the representation is not true to scale and on the other hand, a large plurality of membrane fragments are, as a rule, attached or adsorbed simultaneously to the SSM or the surface 24 a of the sensor electrode device 20 serving as secondary carrier.
[0173] Here, too, it is shown that, by converting the substrate S provided in the measuring medium 30 into a converted substrate S′, a substance transport of the species Q from one side 10 a of the membrane fragment 10 to the opposite side 10 b takes place which can be detected via the corresponding net charge transport and the displacement current connected therewith as a function of the time.
[0174] The invention has been described with particular reference to the preferred embodiments thereof, but it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains.
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The invention relates to a biocompatible sensor electrode arrangement and to a process for its manufacture, at least one carrier substrate area ( 22 ), at least one intermediate substrate area ( 26 ) on the surface area ( 22 a ) of the carrier substrate area ( 22 ) and a biomaterial area ( 24 ) on the top side surface area ( 26 a ) of the intermediate substrate area ( 26 ) being provided. The biomaterial area ( 24 ) consists of at least one biologically compatible material component. The carrier substrate area ( 22 ) with the intermediate substrate area ( 26 ) is formed in the form or the manner of a wafer element or a printed circuit, as photolithographically processed structure, as structure bonded on or laminated on and/or as structure processed by printing, in particular on the carrier substrate ( 22 ) in each case.
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BACKGROUND OF THE INVENTION
Glasses demonstrating relatively high transmission in the infrared region of the radiation spectrum are well known in the art. One rather large use of such glasses has been as elements in the construction of commercial detection systems based upon sensitivity to heat or infrared radiation.
U.S. Pat. No. 3,723,141 provides a brief review of the prior art directed to glass compositions asserted to exhibit good infrared transmission. In general, those prior art glasses had displayed good transmittances to wavelengths no longer than six microns and, commonly, no greater than five microns. The patent described glass compositions in the lead bismuthate system capable of transmitting substantial amounts of infrared radiation at wavelengths longer than six microns. Those glasses consisted essentially, expressed in terms of weight percent on the oxide basis, of
PbO: 10-75
Bi 2 O 3 : 10-85
PbO+Bi 2 O 3 : at least 60
BaO: 2-25
ZnO: 1-10
SiO 2 +B 2 O 3 +P 2 O 5 : <1
Optionally, up to 10% individually and up to 20% collectively of the following oxides may also be present: As 2 O 3 , CaO, CdO, GeO 2 , HgO, Sb 2 O 3 , SrO, TiO 2 , Tl 2 O 3 , the alkali metal oxides, and the colorant or transition metal oxides. A drawing appended to the patent, wherein percent transmission is plotted against transmitting wavelengths, indicated a transmittance of at least 50% at a wavelength of 7.5 microns, but a rapid loss of transmission at longer wavelengths.
U.S. Pat. No. 3,837,868 is asserted to be an improvement upon the glasses of U.S. Pat. No. 3,723,141, wherein those latter glasses were stabilized to better avoid devitrification through the inclusion of Fe 2 O 3 . Those glasses consisted essentially, expressed in terms of cation percent on the oxide basis, of
Bi 2 O 3 : 8-80
PbO: 0-57
CdO: 0-32
PbO+CdO: at least 5%
Fe 2 O 3 : 5-32.5
Optionally, up to 15% total of compatible glassmaking constituents may also be present including up to 7.5% BaO and/or ZnO, up to 5% GeO 2 , V 2 O 5 , NiO, CoO, and other transition metal oxides, and up to 2% B 2 O 3 +SiO 2 .
Rather than repeating the reviews of prior art supplied in those patents, the full disclosures of those patents are explicitly incorporated herein by reference.
SUMMARY OF THE INVENTION
We have discovered a region of glass compositions in the base PbO--Ga 2 O 3 system, to which Bi 2 O 3 is preferably included, which can transmit substantial infrared radiation to a wavelength of 8 microns and can exhibit refractive indices greater than 2.4. Those glasses have base compositions consisting essentially, expressed in terms of weight percent on the oxide basis, of about 72-85% PbO and 15-28% Ga 2 O 3 . The inclusion of Bi 2 O 3 greatly improves the stability of the glasses against devitrification and the melting and forming chracteristics thereof. The chemical durability of these compositions is very good for glasses exhibiting high indices of refraction and infrared transmissions. They demonstrate no weathering after several months' exposure to ambient environments and do not dissolve when immersed into water for extended periods at ambient conditions. Moreover, the addition of Bi 2 O 3 dramatically broadens the scope of operable glass compositions. Thus, Bi 2 O 3 may be incorporated into the glass composition in amounts up to 85% and, in so doing, provides glasses demonstrating the desired infrared transmitting character within the area generally encompassed by the curve depicted on the ternary diagram comprising FIG. 1. A somewhat rough approximation of the operable ternary compositions consists essentially of
PbO: 10-85
Ga 2 O 3 : 5-30
Bi 2 O 3 : up to 85
The following compatible metal oxides in the indicated individual proportions and collectively in an amount not exceeding about 30% may also optionally be present to modify the chemical and physical properties of the glass without significantly altering the infrared radiation transmission capability thereof.
______________________________________Cs.sub.2 O 0-20 Rb.sub.2 O 0-5HgO 0-30 HfO.sub.2 0-5Tl.sub.2 O.sub.3 0-20 Al.sub.2 O.sub.3 0-3Sb.sub.2 O.sub.3 0-10 ZnO 0-5TeO.sub.2 0-10 K.sub.2 O 0-2Cr.sub.2 O.sub.3 0-5 In.sub.2 O.sub.3 0-10MnO.sub.2 0-5 SiO.sub.2 0-2CuO 0-2 ZrO.sub.2 0-5CdO 0-12 Nb.sub.2 O.sub.5 0-5GeO.sub.2 0-5 Ta.sub.2 O.sub.5 0-5Na.sub.2 O 0-2______________________________________
The inclusion of a halogen in an amount up to about 5% is useful in removing water from the glass and thereby eliminating the strong absorption in the infrared region of the radiation spectrum at about three microns which is characteristic of water in glass. Chlorine appears to be the most effective of the halogens in this regard. The application of a halogen to reduce the water content of a glass is disclosed in U.S. Pat. Nos. 3,531,271 and 3,531,306.
PRIOR ART
Inorganic Glass-Forming Systems, H. Rawson, Academic Press, London and New York, 1967, pages 200-1, furnishes a summary of glass compositions in the CaO-Ga 2 O 3 system. Increased glass stability was achieved through the addition of a few percent of SiO 2 .
P. Kantor, A. Revcolevschi, and R. Collongues, "Preparation of Iron Sesquioxide Glasses by Ultra-Fast Quenching from the Melt ("splat cooling")", Journal of Materials Science, 8, pages 1359-61 (1973) describes the formation of glass bodies of very small size dimensions through splat cooling, i.e., essentially instantaneous cooling. Thus, the products consisted of flakes and/or thin films. The publication was concerned principally with compositions in the Fe 2 O 3 --BaO, FeO--CaO, and Fe 2 O 3 --PbO systems, but glasses containing about 40-95 mole percent PbO and 5-60 mole percent Ga 2 O 3 (44.3-95.8 weight percent PbO and 4.2-55.7 weight percent Ga 2 O 3 ) were noted. Such ranges extend far beyond the 72-85% PbO/15-28% Ga 2 O 3 regions of the present inventive glasses, the latter ranges providing commercially practical glassmaking compositions. Moreover, no physical property data were supplied by the authors so no indication was furnished of the very high indices of refraction and transmission in the infrared portion of the radiation spectrum which are exhibited by the present inventive glasses.
U.S. Pat. No. 3,188,216 is concerned with the preparation of glasses having base compositions within the SrO--Ga 2 O 3 system which are capable of transmitting at least 15% of infrared radiation at a wavelength of 6.5 microns. The glasses consist essentially of at least 50% by weight of SrO and Ga 2 O 3 in the ratio of 0.66-1.13 parts of Ga 2 O 3 to one part of SrO and optionally contain up to 45% PbO, up to 35% of at least one oxide selected from the group of Li 2 O, Na 2 O, K 2 O, CaO, and MgO, and up to 40% of at least one oxide selected from the group of CdO, CuO, ZnO, La 2 O 3 , TiO 2 , ZrO 2 , ThO 2 , GeO 2 , Ta 2 O 5 , As 2 O 3 , and Sb 2 O 3 . Fluoride may replace part of the oxide.
U.S. Pat. No. 3,511,992 discusses the production of a glass consisting essentially of 35 atomic percent germanium, 60 atomic percent selenium, and 5 atomic percent gallium. The glass is stated to demonstrate good transmission in the 1-20 micron wavelength regime of the radiation spectrum.
U.S. Pat. No. 4,197,136 is drawn to glasses suitable for use in optical transmission lines. The glasses were composed principally of P 2 O 5 and GeO 2 , with Ga 2 O 3 being added to dramatically improve their resistance to attack by water. The patented compositions consisted essentially, in weight percent, of 10-58% P 2 O 5 , 15-85% GeO 2 , and 5-40% Ga 2 O 3 . No mention is made of the infrared transmission capabilities of the glasses.
U.S. Pat. No. 4,341,542 discloses a method for preparing glasses suitable for use in optical transmission bodies. The method involves precipitating an oxide of a glass forming element by the hydrolysis reaction of a halogen compound of said glass forming element in the liquid phase, adding phosphoric acid to the precipitate to produce phosphate, removing the water from the phosphate, and then firing the phosphate to vitrify it. Glasses useful in the process were asserted to consist essentially, in weight percent, of 45-55% P 2 O 5 , 20-35% Ga 2 O 3 , 10-25% GeO 2 , and 0-10% SiO 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts infrared transmittance curves demonstrated by operable inventive compositions over the range of about 2-8 microns; and
FIG. 2 is a ternary composition diagram of the PbO--Ga 2 O 3 --Bi 2 O 3 system illustrating the basic area of glass compositions displaying the desired infrared transmitting capabilities.
DESCRIPTION OF PREFERRED EMBODIMENTS
Table I reports a number of glass compositions, expressed in terms of approximate weight percent on the oxide basis, illustrating the parameters of the invention. PbO, Bi 2 O 3 , and Ga 2 O 3 constituted the batch ingredients therefor, although it will be appreciated that other starting materials capable, upon being melted together, of being converted into the desired oxide in the proper proportion would be suitable. Because it is not known with which cation(s) the chloride is combined, it is merely recorded in terms of chloride, in accordance with conventional glass analysis practice. In the following example it was batched as lead chloride. Table IA lists the compositions expressed in terms of cationic percent.
The batch components were compounded in the appropriate amounts to yield 50 grams of glass, the batches ballmilled in a polypropylene jar using Al 2 O 3 balls, the batches charged into platinum crucibles, and the crucibles introduced into a furnace operating at 1000° C. After 20 minutes, the melts were poured onto a steel plate and the resultant slabs allowed to cool to room temperature in the ambient environment. A visual description of glass quality is provided in Table I wherein "good" signifies essentially no unmelted batch or devitrification observed, "fair" indicates the inclusion of a minor amount of unmelted batch or devitrification, and "poor" designates the presence of less than 50% glass. Each exemplary composition is positioned in FIG. 2.
In Example 42 dry nitrogen was gently blown across the surface of the melt in order to sweep out the water vapor being volatilized off. Dry nitrogen is a very convenient gas for that purpose because, as supplied commercially, it is quite dry. Nevertheless, as is explained in U.S. Pat. No. 3,531,271, any gas may be utilized for that function so long as it is dry and is essentially inert to the molten glass. Air, helium, and oxygen are explicitly noted as being operable.
Removal of water from the molten glass can also be effected by bubbling a dry halogen-containing gas through the melt. Dry chlorine and dry HCl gases have been disclosed as useful for that purpose.
TABLE I__________________________________________________________________________ 1 2 3 4 5 6 7 8 9 10 11 12 13 14__________________________________________________________________________PbO 82 78 74 71 82 71.5 63.0 60.5 66 46 70.5 63.5 56 51.5Ga.sub.2 O.sub.3 18 22 26 29 12 21.5 29.5 25.5 15 12 7.0 12.0 18 21.5Bi.sub.2 O.sub.3 -- -- -- -- 6 7 7.5 14.0 19 42 22.5 24.5 26 27.0Cs.sub.2 OHgOTl.sub.2 OIn.sub.2 O.sub.3ClQuality Good Good Good Poor Fair Good Good Good Good Good Poor Good Good Poor__________________________________________________________________________ 15 16 17 18 19 20 21 22 23 24 25 26 27 28__________________________________________________________________________PbO 59.5 57.5 43.5 48.0 32.0 30.5 28.5 38.5 41.5 37.5 27.0 26 22.0 18.5Ga.sub.2 O.sub.3 7.0 4.5 18.0 7.5 21.5 18.0 12.0 9.5 4.5 6.5 6.5 4 9.5 18.0Bi.sub.2 O.sub.3 33.5 38.0 38.5 44.5 46.5 51.5 59.5 52.0 54.0 56.0 66.5 70 68.5 63.5Cs.sub.2 OHgOTl.sub.2 OIn.sub.2 O.sub.3ClQuality Good Poor Good Good Poor Poor Good Good Poor Good Good Poor Good Poor__________________________________________________________________________ 29 30 31 32 33 34 35 36 37 38 39 40 41 42__________________________________________________________________________PbO 17 16.0 15.5 11.0 10.5 10.0 6.0 5 40.1 37.6 34.4 37.7 26.2 45.3Ga.sub.2 O.sub.3 12 6.5 4.0 9.5 6.5 4.5 11.5 2 10.5 9.9 9.0 9.9 15.6 11.9Bi.sub.2 O.sub.3 71 77.5 80.5 79.5 83.0 85.5 82.5 93 36.7 34.3 31.5 34.5 50.1 41.4Cs.sub.2 O 12.7 -- -- -- -- --HgO -- 18.2 25.1 -- -- --Tl.sub.2 O -- -- -- 17.9 -- --In.sub.2 O.sub.3 -- -- -- -- 8.1 --Cl -- -- -- -- -- 1.4Quality Good Good Poor Good Good Poor Fair Poor Good Good Good Good Good Good__________________________________________________________________________
TABLE IA__________________________________________________________________________ 1 2 3 4 5 6 7 8 9 10 11 12 13 14__________________________________________________________________________PbO 65 60 55 50 70 55 45 45 55 40 65 55 45 40Ga.sub.2 O.sub.3 35 40 45 50 25 40 50 45 30 25 25 25 35 40Bi.sub.2 O.sub.3 -- -- -- -- 5 5 5 10 15 35 20 20 20 20Cs.sub.2 OHgOTl.sub.2 OIn.sub.2 O.sub.3Cl__________________________________________________________________________ 15 16 17 18 19 20 21 22 23 24 25 26 27 28__________________________________________________________________________PbO 55 55 35 45 25 25 25 35 40 35 25 25 20 15Ga.sub.2 O.sub.3 15 10 35 15 40 35 25 20 10 15 15 10 20 35Bi.sub.2 O.sub.3 30 35 30 40 35 40 50 45 50 50 60 65 60 50Cs.sub.2 OHgOTl.sub.2 OIn.sub.2 O.sub.3Cl__________________________________________________________________________ 29 30 31 32 33 34 35 36 37 38 39 40 41 42__________________________________________________________________________PbO 15 15 15 10 10 10 5 5 33.3 33.3 30.8 33.3 21.1 39.983Ga.sub.2 O.sub.3 25 15 10 20 15 10 25 5 21.8 21.8 19.2 21.8 29.8 24.990Bi.sub.2 O.sub.3 60 70 75 70 75 80 70 90 29.2 29.2 26.9 29.2 38.6 34.985Cs.sub.2 O 16.7 -- -- -- -- --HgO -- 16.7 23.1 -- -- --Tl.sub.2 O -- -- -- 16.7 -- --In.sub.2 O -- -- -- -- 10.5 --Cl -- -- -- -- -- 0.042__________________________________________________________________________
Table II records the annealing point (Ann. Pt.), strain point (Str. Pt.), coefficient of thermal expansion (Coef. Exp.) over the range of 25°-200° C. in terms of ×10 -7 /°C., and refractive index (R.I.) determined on several of the exemplary compositions of Table I utilizing measuring techniques conventional in the glass art.
TABLE II______________________________________2 6 21 37 38 39 40 41______________________________________Ann. 375° C. 383° C. -- -- -- -- -- --Pt.Str. 351° C. 360° C. -- -- -- -- -- --Pt.Coef. 87.6 83.5 111.3 -- -- -- -- --Exp.R.I. 2.43 2.21 2.39 2.27 2.45 2.53 2.35 2.31______________________________________
FIG. 1 sets out infrared transmittance curves exhibited by Examples 2, 10, and 42. Curve 1 represents Example 2, a binary PbO--Ga 2 O 3 composition; Curve 2 designates Example 10, a ternary PbO--Ga 2 O 3 --Bi 2 O 3 composition; and Curve 3 illustrates the marked effect which the removal of water from the glass can have upon the infrared transmission of the glass. Example 42 represents Example 10 to which chloride was added. As is evident from Curve 3, an essentially totally dry glass would display transmittances in excess of 60% out to wavelengths of 6.5 microns and beyond.
Example 10 demonstrated exceptionally good glass quality and so was selected for further examination. To undertake such examination, a batch appropriate to yield 500 grams of glass was compounded, ballmilled and melted in platinum crucibles in like manner to the description above. The melt was cast into a graphite mold preheated to 350° C. to produce a rectangular slab having dimensions of about 7.5 cm×3 cm×1.3 cm and this slab annealed at 350° C. The resulting body exhibited a coefficient of thermal expansion (25°-200° C.) of 111.6×10 -7 /°C., an annealing point of 319° C., a strain point of 297° C., and a refractive index of 2.46±0.05.
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This invention is directed to the preparation of glasses in the PbO--Ga 2 O 3 field exhibiting good infrared transmitting characteristics out to wavelengths of 8 microns. The binary glasses consist essentially, by weight, of about 15-28% Ga 2 O 3 and 72-85% PbO. However, the preferred glasses contain up to 85% Bi 2 O 3 and consist essentially as included within the area generally encompassed by the curve in FIG. 2.
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FIELD OF THE INVENTION
This invention relates to radar and other microwave antennas. By “microwave antenna” we mean one having an operating frequency of at least 300 MHz. The invention is particularly but not exclusively suitable for phased arrays.
Phased array antenna systems are well known in the antenna art. Such antennas generally comprise a plurality of radiating antennas that are individually controllable with regard to relative phase and amplitude. The antenna pattern of the array is selectively determined by the geometry of the individual antennas and the selected phase/amplitude relationships among the antennas. Typical radiating elements for such antenna systems may comprise dipoles, slots or any other suitable arrangement.
Microwave antennas include a wide variety of designs for various applications, such as satellite reception, remote broadcasting, or military communication. For low profile applications printed circuit antennas may be used.
RELATED ART
A schematic diagram of a low profile, highly coupled dipole array is illustrated in FIG. 1 . This particular array comprises a periodic arrangement of dipoles each having a span (periodicity) of around 10 mm. The target bandwidth of the antenna array is approximately 2 GHz to 18 GHz. Such antennas are more attractive for use in a low profile antenna than antennas using Vivaldi elements, for example, which are much taller for a similar range of frequencies.
Such a dipole array usually forms part of a layered structure, including a dielectric substrate upon which the dipole array is printed and dielectric spacer material separating the dipole array from a ground plane. Further dielectric layers may also be included to improve the performance at wide scan angles.
However, there is a problem with using such a highly coupled dipole array for applications requiring a low profile antenna. Such antennas have a so-called “vertical” feed structure to connect the elements of the dipole array to a driving circuit which extends through the ground plane. By “vertical” is meant substantially normal or perpendicular to the plane of the dipole array.
A problem arises with feeding a planar array of dipoles, for example, because the vertical feed structure will support unwanted currents. In a scanned array, these unwanted currents are present even when using a balanced feed structure such as twin wire transmission line. These currents are excited at the frequencies and range of scan angles over which the antenna will work effectively.
In order to avoid the problem of such unwanted common-mode currents due to the feed structure it would be possible to feed an array of dipoles using an optical fibre feeding an active device. However, this solution would be expensive and largely constrained to receive-only applications due to the limited transmit power. Furthermore whilst an optical feed structure might be possible at lower frequencies which mean larger dipole structures due to larger wavelengths this will become less feasible for smaller dipole structures such as those working around 10 GHz.
It is desirable to produce a phased array antenna having high bandwidth and high scan range whilst also having a low profile and being light in weight. Of course, it is also desirable to produce such antenna at as low a cost as possible.
Our co-pending patent application, published as WO 2009/047553, seeks to provide one solution to this problem of unwanted common-mode currents by at least partially surrounding each feed structure with a ferrite element to suppress the unwanted currents over the feed structure. The present invention offers an alternative approach.
In one aspect the invention provides a radar or other microwave antenna comprising at least one antenna element, a feed structure for the element extending to the antenna element substantially normally thereto through a dielectric substrate, and characterized in that the dielectric substrate is anisotropic thereby to reduce unwanted common-mode currents in the feed structure.
The invention also provides an antenna array (which may be a phased array) having a number of antenna elements as set forth above. The following optional features may be included in the antenna element or the array, as appropriate.
The dielectric substrate may selectively present an impedance to electric fields polarized in a first direction, parallel to the feed structure, which is relatively high compared to an impedance presented to electric fields polarized orthogonally to that first direction.
The dielectric substrate may comprise elongate electrically conductive elements having their longitudinal axes generally aligned in the first direction, and being distributed through the dielectric substrate. The pins may therefore be distributed to surround the feed structure. Such distribution of the electrically conductive elements throughout the substrate may provide that the electrically conductive elements are disposed beneath an antenna element, or in other words: the conductive element axis may be coincident with the antenna element.
Thus in another aspect the invention provides a radar or other microwave antenna comprising at least one antenna element disposed in an antenna substrate, a feed structure for the element extending to the element substantially normally thereto through a dielectric substrate, and characterized by an array of discrete elongate elements distributed through the dielectric substrate, the elements being spaced from the feed structure and disposed with their longitudinal axes aligned in a first direction that is parallel to the feed structure.
The elongate elements may present relatively high impedance to electric fields polarized in that first direction.
The antenna elements may be spaced apart in at least one direction, the spacing of the elongate elements in that at least one direction being regular from element to element and being a sub-multiple of the dimension (periodicity) of the antenna elements in that at least one direction.
Thus the antennas may be spaced apart in two orthogonal directions, the spacing of the elongate elements in each of the two orthogonal directions being a sub-multiple of the dimension (periodicity) of the antenna elements in each of those two orthogonal directions.
The said spacing of the elongate elements may be one half to one eighth and preferably one fourth of the respective dimension of the antenna elements.
The elongate elements may be spaced apart by a distance several times less, for example 4 to 16 times less, preferably 8 times less than the shortest wavelength of signals which the antenna is designed to transmit or receive.
The antenna elements may comprise pairs of dipoles, one of which dipoles is aligned in a second direction, the other of which is aligned orthogonally to the first and second directions.
The elongate elements may extend only partially through the thickness of the dielectric substrate normal to the antenna element.
The dielectric material may extend from the antenna element to a ground plane disposed substantially parallel to said antenna element, the elongate elements having ends spaced from at least one of the substrate and the ground plane.
The length of the elongate elements may be between 50% and 90% of the distance between the antenna element and the ground plane, and preferably about 70%. The elongate elements may be rod-like.
The elongate elements may be circular in section and have a length to diameter ratio in the range of between 5 and 15 to 1 and preferably 7 to 1.
The elongate elements in operation may couple capacitively to the ground plane.
The elongate elements may be made of copper or aluminium or other electrically conducting materials.
The dielectric substrate may be of a material of relatively low dielectric constant, preferably chosen from amongst low density foam materials such as closed-cell polyurethane foam.
The invention will now be described merely by way of example with reference to the accompanying drawings, wherein:
FIG. 1 is an illustration of one example of a highly coupled dipole array for use in a phased array antenna;
FIG. 2 is a second example of a highly coupled dipole array for use in a phased array antenna;
FIG. 3 is an illustration of an antenna element showing various layers in an antenna structure.
FIG. 4 a is an illustration of balanced currents in a feed structure;
FIG. 4 b is an example of an unbalanced current in a feed structure, and
FIGS. 5 and 6 are an illustration of an embodiment of the present inventions, FIG. 6 being a section on line 6 - 6 of FIG. 5 .
DETAILED DESCRIPTION
FIG. 1 illustrates schematically a highly coupled dipole array 11 comprising a substantially planar periodic arrangement of antenna elements 12 . Each antenna element 12 comprises four conducting arms 13 which form two orthogonal dipole antennas and provide dual polarisation. T-shaped elements 14 at the end of each arm 13 increase the series capacitance between adjacent antenna elements 12 in order to improve the antenna bandwidth. Each conducting arm has a feed portion 15 located at the centre of the antenna element 12 for receiving an electrical signal. A dielectric substrate for supporting the dipole array 11 (as is conventional in printed circuit antennas) is not shown.
FIG. 2 illustrates schematically a second example of a highly coupled dipole array 21 comprising a substantially planar periodic arrangement of antenna elements 22 supported by a thin dielectric substrate (not shown in FIG. 2 ). Each antenna element 22 comprises four substantially identical conducting arms 23 which form two orthogonal dipole antennas and provide dual polarisation. Parallel line coupling elements 24 which are provided on the opposite side of the thin dielectric substrate to that of the dipole elements serve to increase the series capacitance between adjacent antenna elements 22 in order to improve the antenna bandwidth. A section Z-Z of the antenna array is shown in FIG. 2 (with the thickness of the arms 23 and the coupling element 24 greatly exaggerated) to illustrate a side view of a coupling element 24 .
It will be appreciated that the arrangement shown in FIG. 2 is not as convenient as the arrangement shown in FIG. 1 if it is desired to produce a dipole array spanning more than one substrate section as a coupling element 24 would have to span two substrate sections.
FIG. 3 is a perspective view of an antenna element 22 shown in FIG. 2 illustrating the layers which were used in an antenna simulation. The antenna element 22 includes a feed structure 32 comprising a coaxial cable feeding each conducting arm 23 (a conducting arm from each of four adjacent antenna elements are also shown). A spacer layer 34 of a dielectric material separates the layer of conducting arms 23 from a ground plane layer (not shown). A relatively thin dielectric substrate layer 36 supports the conducting arms 23 and coupling elements 24 .
Because the substrate layer 36 has a dielectric constant of 2.2 and air has a dielectric constant of approximately 1, further dielectric layers—a first dielectric layer 38 and a second dielectric layer 40 —are provided to cover the layer of conducting arms 23 to smooth the differences in the dielectric properties between the substrate 36 and air and to improve the scan angle of an antenna array 21 made up of a periodic structure of the antenna elements 22 . In this example, a first dielectric layer 38 having a dielectric constant of 2.0 supports a second dielectric layer 40 having a dielectric constant of 1.33 between the substrate layer 36 and air. In this description the feed structure is sometimes referred to as a vertical feed structure, although it will be appreciated that an antenna array 21 may be in any orientation when in use.
The effective scanning angle of a phased array antenna is limited by the voltage standing wave ratio (VSWR) achieved in the feed structure when phases are applied to the antenna elements in order to scan in the plane of the electric field (the E plane) and the plane of the magnetic field (the H plane) which are orthogonal to one another. Predictions of the VSWR performance can be generated using conventional antenna modelling software.
Ideally the VSWR should be below 2:1 but a ratio of 2.5:1 can be tolerated for very wide bandwidth and scan angle operation.
Excessive VSWR can arise due to unwanted currents in the feed structure 32 . FIGS. 4 a and 4 b show conductive arms 23 fed by a feed structure 32 , each conductive arm 23 being fed by a coaxial cable 50 . FIG. 4 a illustrates, by means of arrows, balanced currents in the feed structure. FIG. 4 b on the other hand shows undesirable unbalanced or common mode currents which if not suppressed will cause noise in signals received by the conductive arms 23 .
In a preferred embodiment of the invention, shown in FIGS. 5 and 6 , the undesirable common mode currents are suppressed by concentrating the horizontally propagating vertically-polarized electric fields which produce them into an array of conductive rods distributed through the dielectric material of spacer layer 34 surrounding and spaced apart from the feed structures 32 . The dimensions of the rods are chosen to cause the currents to dissipate rather than travel in the feed structure. Furthermore, the spacing and distribution of the rods is chosen so as to appear homogeneous to signals at the operational wavelengths for the antenna.
Referring to FIGS. 5 and 6 (in which previously described items are labelled with the same reference numerals), an antenna element structure 60 is shown in which conducting elements 63 of an antenna element 62 are in this embodiment triangular in shape so as to increase the series capacitance between the conducting elements 63 of adjacent antenna elements 62 . The dielectric layers 38 and 40 of FIG. 3 are present also in this structure 60 , although not shown. The feed structure 32 is located at the centre of the antenna element structure 60 in a manner already described with reference to FIGS. 1 and 3 .
The feed structure 32 and the conducting elements 63 in this example are set at a pitch of 13 mm in both the x and y directions in the substrate layer 36 . Thus, the periodicity of antenna elements in an array antenna comprising a periodic arrangement of the square antenna elements 62 is 13 mm. The substrate layer 36 is positioned 10.4 mm above a base substrate 46 which includes a strip-line ground plane.
The spacer layer 34 consists of material of a relatively low dielectric constant (for example polyurethane foam, which has a dielectric constant approximating to that of free space, or other low density foam) in which are distributed an array of parallel, vertical, substantially equally spaced elongate rods 51 of for example copper or aluminium alloy or other electrically conducting material. The rods 51 are set at a pitch of 3.25 mm in the x and y directions, one quarter the (13 mm) pitch of the antenna elements 62 . The antenna array is designed for use at a maximum frequency of 11.5 GHz, equivalent to a wavelength of 26 mm. The pitch of the conductive rods 51 is thus one eighth of a wavelength and that of the antenna elements is one half of the wavelength of the highest frequency signals for which the antenna is designed.
In this example the rods are 7.2 mm long and are of circular section with a diameter of 1.0 mm. Their length to diameter ratio is thus 7.2:1. The rods 51 are suspended in the dielectric material 34 so that the lower end of each rod 51 is 0.7 mm from the ground plane and the upper end is 2.5 mm from the underside of the substrate layer 36 . The lower end of the rod 51 is capacitively coupled to the ground plane due to its proximity thereto and acts in combination with the inductance of the rod 51 to form a tuned circuit that dissipates the energy in the unwanted electric fields. Due to the relatively large gap between the top of the rods 51 and the antenna elements 62 there is negligible coupling between them.
The elongate shape of the rods 51 and their parallel vertical orientation between the conducting elements 63 and the ground plane layer 46 results in the dielectric layer 34 having different properties in the z direction (normal to the conducting elements 63 ) compared to its properties in the x and y directions. This enables the vertically polarized fields inducing undesirable common-mode currents to be suppressed whilst having little effect on the horizontally polarized fields associated with the induced currents in the conducting elements 63 of the antenna elements 62 which are necessary for transmission and reception.
To facilitate manufacture, the spacer layer comprises upper and lower portions 52 , 54 , shown in FIG. 6 , each with an array of blind holes to receive the rods 51 . The rods are placed in the lower portion 54 and then the upper portion 52 is placed on top and bonded to the lower portion 54 , or vice versa.
It will be appreciated that various alterations, modifications, and/or additions may be introduced into the constructions, arrangements and dimensions of parts described above without departing from the scope of the present invention as defined in the appended claims.
Although the invention has been discussed specifically referring to co-axial cables, other vertical feed structures, for example strip line or any other electrical conductor feeding an antenna array in parallel may benefit from the invention.
Although the invention has been described, using two dielectric layers 38 , 40 between the antenna array and air, fewer, more or no dielectric layers may be used. Furthermore the portions 52 , 54 of dielectric layer 34 may be of different materials.
Although the invention has been described in the context of arrays of antennas having four conducting arms (elements), the invention may also benefit arrays of antenna elements having two conducting arms and may also benefit other types of antenna or antenna array structures where a parallel (or ‘vertical’) electrical feed structure is required.
The dimensions and material properties described above relate to a specific example array antenna. However, variations are possible, according to the intended frequency range of operation of the antenna, which would be understood by a person of ordinary skill in the art and which fall within the scope of the present invention as defined in the claims.
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A radar or other microwave antenna comprises at least one antenna element, a feed structure for the element extending to the antenna element substantially normally thereto through a dielectric substrate, and characterized in that the dielectric substrate is anisotropic whereby to reduce unwanted common-mode currents in the feed structure. The anisotropy may be provided by elongate conductive elements distributed through the dielectric substrate and aligned with their longitudinal axes parallel to the feed structure.
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BACKGROUND OF INVENTION
In the past, hunters have used various devices to call game, such as the ubiquitous tube call, in which air is blown through a mouthpiece and over a reed to generate sound. Other calls, such as described in U.S. Pat. No. 6,254,451 issued to Ron M. Bean for a “Game Call with Volume Control”, have used a flexible bellows or bulb attached to a tube call to eliminate the need for blowing through the mouthpiece. In both of these examples, sound is produced pneumatically by air flowing over a reed or diaphragm, which induces vibration.
While these calls have many advantages, they also have significant drawbacks.
First of all, the skill required to successfully operate a pneumatically driven call at a low volume is often more than is possessed by inexperienced or infrequent hunters and game callers.
Secondly, in some calls, the lower volume threshold for normal operation may exceed a desired volume level.
Thirdly, the calls using bellows and bulbs have often had limited operational characteristics, owing to the lessened control that a bellows often has in comparison to a mouth-blown call.
Consequently, there exists a need for improvement in game calling methods and apparatuses.
SUMMARY OF INVENTION
It is an object of the present invention to provide an easily operated game call having volume variation capabilities.
It is a feature of the present invention to include an adjustable sound output port.
It is an advantage of the present invention to allow for manipulation of the call volume in an easy-to-use fashion.
It is another advantage of the present invention to increase the certainty that the call will produce an appropriate sound.
The present invention is an apparatus and method for calling game which is designed to satisfy the aforementioned needs, provide the previously stated objects, include the above-listed features and achieve the already articulated advantages. The present invention is carried out in an “error-less multi-volume” approach in a sense that the amount of errant sounds, which often are produced when attempting to make a softer sound in a pneumatically driven call, is dramatically reduced.
Accordingly, the present invention is an apparatus and method for controlling the volume of a game call which includes a twistable and partially open sleeve disposed axially about an inner sound chamber with a sound port therein.
BRIEF DESCRIPTION OF DRAWINGS
The invention may be more fully understood by reading the following description of the preferred embodiments of the invention, in conjunction with the appended drawings wherein:
FIG. 1 is a partially exploded perspective view of the game call and call volume control of the present invention.
FIG. 2 is a side view of the assembled call volume control of FIG. 1 .
FIG. 3 is a cross-sectional view taken on line A—A of FIG. 1 .
FIG. 4 is an end view of an inner chamber of an alternate embodiment of the present invention.
FIG. 5 is a side view of the inner chamber taken from line A—A of FIG. 4 .
FIG. 6 is a cross-sectional view of the inner chamber taken on line B—B of FIG. 4 .
FIG. 7 is a side view of an embodiment of the present invention which shows dual alternately oriented inner chamber sound exiting ports.
DETAILED DESCRIPTION
Now referring to the drawings, wherein like numerals refer to like matter throughout, and more particularly to FIG. 1, there is shown a game call 1 and game call volume control 100 , with an airflow axis 101 and also which includes a game call sound outlet end 102 , a game call volume control inner chamber 104 , a game call volume control outer chamber 106 , and an outer chamber to inner chamber fastener 108 . Game call 1 could be a hand-operated squeezable bellows—type call, as shown, or a mouth or lip-blown call or any type of pneumatic game call.
Game call sound outlet end 102 , game call volume control inner chamber 104 and game call volume control outer chamber 106 could be any suitable material, such as wood, PVC, or other synthetic material which is sufficiently rigid to permit proper operation of the present invention. Outer chamber to inner chamber fastener 108 could be of similar material.
Game call volume control 100 is intended to be affixed to or integrated with a game call sound outlet end 102 of any type of pneumatically driven game call.
Game call sound outlet end 102 is shown as including a game call body 120 having one or more O-ring grooves 126 therein. Game call sound outlet end 102 includes a game call sound outlet terminal end 122 , which is inserted into or integrated with game call volume control inner chamber 104 . When game call sound outlet terminal end 122 is inserted into game call volume control inner chamber 104 , one or more O-rings 124 are disposed in O-ring grooves 126 to maintain a pneumatic seal. Other means of sealing game call sound outlet end 102 to game call volume control inner chamber 104 could be substituted. No means of sealing game call sound outlet end 102 to game call volume control inner chamber 104 would be needed if they were integrated.
Game call volume control inner chamber 104 may have an inner chamber inlet end 140 which receives game call sound outlet terminal end 122 . Game call volume control inner chamber 104 may have an inner chamber unsleeved exterior section 142 and an inner chamber sleeved interior section 144 . Preferably, inner chamber sleeved interior section 144 has a decreasing cross-sectional diameter going from inner chamber unsleeved exterior section 142 to inner chamber outlet end 148 . Inner chamber sleeved interior section 144 may have at least one, but preferably two or more, inner chamber sound exiting ports 146 . Preferably, inner chamber sound exiting port 146 is not a simple narrow slot running along the longitudinal axis of game call volume control 100 from game call body 120 to airflow exit orifice 110 . Preferably, inner chamber sound exiting port 146 is a generally triangular shaped orifice in the side of inner chamber sleeved interior section 144 between inner chamber unsleeved exterior section 142 and inner chamber outlet end 148 . It should be understood that the present invention is described as a twisting volume control; however, a sliding volume control could be substituted. When a sliding volume control is used, it will likely be necessary to change the shape and orientations of inner chamber sound exiting port 146 and outer chamber sound exiting port 166 . The concept, a variably sized exposed inner port, would be readily implemented in many different configurations.
Inner chamber outlet end 148 may be configured to be inserted into game call volume control outer chamber 106 at the outer chamber inlet end 160 . Game call volume control outer chamber 106 may have an outer chamber exit end 164 and an outer chamber sound exiting port 166 in outer chamber sleeve 162 . An outer chamber sound exiting measurement scale 168 is preferred to be located adjacent to outer chamber sound exiting port 166 so as to provide a visual indication of a volume setting for the game call volume control 100 . It may be preferred to have inner chamber sleeved interior section 144 have a contrasting color in comparison to outer chamber sleeve 162 . Inner chamber outlet end 148 may be colored the same as outer chamber sleeve 162 or inner chamber sleeved interior section 144 .
Outer chamber to inner chamber fastener 108 with an airflow exit orifice 110 therein may be attached to game call volume control outer chamber 106 and game call volume control inner chamber 104 to hold the same in contact. Alternate configurations of attachment between game call volume control inner chamber 104 and game call volume control outer chamber 106 can be substituted. FIGS. 4-6 include an alternate means for coupling.
Now referring to FIG. 2, there is shown a side view of the game call volume control 100 of FIG. 1 in a fully assembled configuration.
Now referring to FIG. 3, there is shown a cross-sectional view of the game call volume control 100 taken along line A—A of FIG. 1 .
Now referring to FIG. 4, there is shown an alternate embodiment of the present invention which includes a fastener integrated game call volume control inner chamber 404 and an integrated fastener 408 . Otherwise, game call volume control inner chamber 104 and fastener integrated game call volume control inner chamber 404 are nearly identical. FIG. 4 shows an end view of fastener integrated game call volume control inner chamber 404 looking through airflow exit orifice 110 toward inner chamber inlet end 140 . Two inner chamber sound exiting ports 146 are shown disposed on opposing sides of inner chamber sleeved interior section 144 .
FIG. 5 shows a side view of the fastener integrated game call volume control inner chamber 404 taken from line A—A of FIG. 4 .
FIG. 6 shows a cross-sectional view of the fastener integrated game call volume control inner chamber 404 taken on line B—B of FIG. 4 .
In operation, the present invention accomplishes the goal of generating sounds with variable volume characteristics as follows: air is moved through game call body 120 , and a sound is produced therein. The air moves through game call volume control 100 , while the sound vibrations propagate through the moving air. When the sound vibrations meet inner chamber sound exiting port 146 , the vibration is permitted to propagate into any void exposed by inner chamber sound exiting port 146 . However, depending upon the orientation of outer chamber sound exiting port 166 on game call volume control outer chamber 106 with respect to inner chamber sound exiting port 146 , propagation of the sound radially from the longitudinal axis of game call volume control 100 can be permitted, precluded or variably permitted. When outer chamber sound exiting port 166 is aligned with a full-length segment of inner chamber sound exiting port 146 , then the volume of sound emitting from outer chamber sound exiting port 166 is maximized. Likewise, when outer chamber sound exiting port 166 is aligned with a solid section of inner chamber sleeved interior section 144 , then sound emitting from the inner chamber sound exiting port 146 is minimized. Variable sound volume levels are achievable by twisting game call volume control outer chamber 106 , so that outer chamber sound exiting port 166 registers with variable lengths of inner chamber sound exiting port 146 . Outer chamber sound exiting measurement scale 168 can be used to determine the volume setting by visual inspection of the relative size of the opening of inner chamber sound exiting port 146 , which is visible through outer chamber sound exiting port 166 .
Now referring to FIG. 7, there is shown an embodiment of the present invention which includes a first inner chamber sound exiting port and a second inner chamber sound exiting port 145 . Inner chamber sleeved interior section 144 is shown to have a tapered shape so as to create a sound chamber capable of producing varying tones at various positions within game call volume control inner chamber 104 . First inner chamber sound exiting port 146 has a first wide end 147 , while second inner chamber sound exiting port 145 has a second wide end 149 , which is in opposition along said first linear axis 101 . Depending on which port is in alignment with outer chamber sound exiting port 166 , the tonal characteristic of the sound output by the game call can be regulated as well.
It is thought that the method and apparatus of the present invention will be understood from the foregoing description and that it will be apparent that various changes may be made in the form, construct steps and arrangement of the parts and steps thereof, without departing from the spirit and scope of the invention, or sacrificing all of their material advantages. The form herein described is merely a preferred exemplary embodiment thereof.
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A game call with a game call multi-colored volume and tone control which includes a game call volume and tone control-tapered inner chamber and a rotatable game call volume and tone control outer chamber having an outer chamber sound exiting port which variably exposes alternately oriented inner chamber sound exiting ports.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part (CIP) of copending U.S. application Ser. No. 10/317,744 filed Dec. 12, 2002 (now U.S. Pat. No. 6,661,957 issued Dec. 09, 2003) which was a continuation-in-part (CIP) of copending U.S. application Ser. No. 09/907,241 filed Jul. 17, 2001 (now U.S. Pat. No. 6,496,634 issued Dec. 17, 2002), the above applications being incorporated herein by reference in their entirety including incorporated material.
FIELD OF THE INVENTION
The field of the invention is the field of optical fibers for the conduction of electromagnetic radiation, wherein the fibers have holes running along the fiber axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a “holey” optical fiber of the invention.
FIG. 2 is a sketch of the system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Copending U.S. application Ser. No. 10/317,744 filed Dec. 12, 2002 (now U.S. Pat. No. 6,661,957 issued Dec. 09, 2003) and its parent application Ser. No. 09/907,241 filed Jul. 17, 2001 (now U.S. Pat. No. 6,496,634 issued Dec. 17, 2002), included a detailed description of an optical fiber having fluid filled holes for Raman amplification of light. FIG. 1 shows a sketch of a cross section of the optical fiber 10 of the invention. The fiber 10 comprises a core region 12 and a transparent cladding region 14 surrounding the core region. The core region contains a plurality of holes 16 elongated in the axial direction of the fiber. The core region may or may not contain a central hole region 18 . The walls of at least one hole or the central region have an optically active material 17 adsorbed on to the wall.
Optical fibers will have a useful life measured in decades, and the material of the cladding 14 is usually fused silica.
When light is propagated down the fiber 10 , it will propagate a great distance with high power. If the optically active material 17 is a Raman active material, Raman light will be generated and will also propagate down the axis of the fiber or may escape through the transparent walls of the fiber. The Raman light may be detected and thus the presence of the Raman active material may be detected.
Similarly, if the adsorbed material is an infrared, visible, or ultraviolet active material, light propagating down the optical fiber will be absorbed or scattered or fluoresced, and the presence of the material can be detected by detectors placed either at the output of the axis of the fiber or at the side of the fiber.
It is well known that molecules adsorbed on surfaces often have a much enhanced Raman cross section. Polar molecules such as air pollutants carbon monoxide, nitrogen oxide, and nitrogen dioxide are particularly preferred embodiments of the invention. Detection of biothreat materials such as bacteria and nerve gas material are also preferred embodiments of the invention. For purposes of investigation of relatively large entities like bacteria, the central hole region 18 may be much larger than the core region of a single mode optical fiber.
The method of the invention comprises introducing optically active molecules or other entities into the hollow core region 18 or into the holes 16 of the holey fiber, and propagating light down the axis of the core. The light will be guided by the holey fiber, and the intensity and interaction length will be much larger than if the light is merely focused in a gas or other fluid medium. It is well known that optically active molecules like carbon monoxide or nitrous oxide can be made to “stick” to either the clean walls of the holes or to specially prepared material of the walls.
FIG. 2 shows a sketch of the system of the invention. Light output from one or more lasers or other sources of light 22 is introduced into the fiber of the invention 20 by an optical apparatus 24 as is known in the art. Optical apparatus 26 is used to conduct light from the fiber 20 to detectors, spectral analysis units, signal splitters, demodulators, etc 28 as are known in the art. Control apparatus 26 controls the light generator 22 and optical apparatus 24 and communicates with detectors etc. 28 .
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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The interior surfaces of the holes in holey optical fibers has adsorbed optically material which may be detected by propagating laser light down the axis of the fiber and detecting Raman, Infrared, or visible fluorescence or absorption.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 09/129,058 filed Aug. 4, 1998, pending, and which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention generally relates to structural members adapted to reinforce a product. The present invention also relates to methods of utilizing the structural member to form reinforced products.
BACKGROUND OF THE INVENTION
Structures formed of concrete and other masonry or cementitious materials often require reinforcement in their construction. These concrete materials have low tensile strength yet have good compressive strength. When using concrete as a structural member, for example, in a bridge, building or the like, reinforcement is often used to impart the necessary tensile strength. In new and existing concrete structures, such as precast driveways, slabs, sidewalks, pipe etc., reinforcement has been undertaken with a variety of steel shapes such as open steel meshes, steel rebar, and steel grids. Steel grids have been used in reinforcing concrete structures such as decking for drawbridges. These steel grids are a closed cell structure, and each section of steel grid contains and confines a rectangular or square column of concrete. These types of grids are inherently very inefficient in their use of the reinforcing material.
Steel and other metals used as a reinforcing agent are subject to corrosion. The products of corrosion result in an expansion of the column of the steel which causes a “spalling” effect which can cause a breakup and deterioration of the concrete structure. This breaking and crumbling of concrete structures is severe in areas of high humidity and areas where salt is used frequently on roads, driveways and sidewalks to melt ice or snow. Bridges over waterways in areas such as the Florida coast or Florida Keys are exposed to ocean air which causes deterioration and a short lifespan requiring constant rebuilding of these bridges. Concrete structures in the Middle East use concrete made with the local acidic sand which also causes corrosion of steel reinforcements.
In addition, because of the potential for spalling due to corroded metal reinforcing members, such configurations typically require a minimum of one inch or more of “cover” meaning that the steel reinforcing members are spaced at least about one inch from the surface of the concrete. This requires that the design thickness of concrete members, such as panels, must be of a certain minimum thickness, usually about three inches, to allow for the thickness of the steel reinforcing member and about one inch of concrete on either side of the reinforcing member. This minimum thickness to avoid spalling causes certain design constraints and requires a relatively high weight per square foot of surface area of the panel.
To replace traditional steel in reinforcing concrete, many types of plastics have been considered. One attempted replacement for steel in reinforcement uses steel rebars coated with epoxy resin. Complete coating coverage of the steel with epoxy, however, is difficult. Also, due to the harsh handling conditions in the field, the surface of the epoxy coated steel rebars frequently will be nicked. This nicking results in the promotion of localized, aggressive corrosion of the steel and results in the same problems as described above.
Fiberglass composite rebars have been used in reinforcing concrete structures such as the walls and floors of x-ray rooms in hospitals where metallic forms of reinforcement are not permitted. The method of use is similar to steel rebars. The fiberglass composite rebars have longitudinal discrete forms which are configured into matrixes using manual labor. Concrete is then poured onto this matrix structure arrangement.
Fiberglass composite rebars are similar to steel rebars in that the surface is deformed. Fiberglass gratings which are similar to steel walkway gratings also have been used as reinforcements in concrete, but their construction, which forms solid walls, does not allow the free movement of matrix material. This is due to the fact that the “Z” axis or vertical axis reinforcements form solid walls.
In dealing with reinforcing concrete support columns or structures, wraps have been applied around the columns to act like girdles and prevent the concrete from expanding and crumbling. Concrete is not a ductile material, thus, this type of reinforcing is for only the external portion of the column. One type of wrap consists of wrapping a fabric impregnated with a liquid thermosetting resin around the columns. The typical construction of these wraps has glass fiber in the hoop direction of the column and glass and Kevlar fibers in the column length direction. Another approach uses carbon fiber unidirectional (hoop direction) impregnated strips or strands which are designed to be wound under tension around deteriorated columns. The resulting composite is cured in place using an external heat source. In these approaches the materials used in the reinforcing wraps are essentially applied to the concrete column in an uncured state, although a prepreg substrate may be employed which is in a “semi-cured” state, i.e. cured to the B-stage. When using a woven fabric, “kinking” can take place when using either carbon or glass fibers, because the weaving process induces inherent “kinks” in either a woven wet laminate or woven prepreg, which results in a less than perfectly straight fiber being wrapped around the column.
Another approach to reinforcing concrete structures and columns is to weld steel plates around the concrete columns to give support to the concrete wall. Such steel plates are also subject to corrosion and loosening resulting from deterioration of the column being supported. This approach is only an external reinforcement and lacks an acceptable aesthetic appearance which makes it undesirable.
An approach to reinforcing concrete mixes has been using short (¼ to 1″) steel, nylon or polypropylene fibers. Bare “E-type” glass fibers are generally not used due to the susceptibility of glass fibers to alkaline attack in Portland cement.
An exemplary structural reinforcing member for asphalt and concrete roadways and other structures is provided in U.S. Pat. No. 5,836,715, which is incorporated herein by reference. The reinforcing member disclosed therein comprises a gridwork having a set of warp strands and a set of weft strands disposed at substantially right angles to each other. The gridwork is impregnated substantially throughout with a resin so as to interlock the strands at their crossover points. The set of warp strands is separated into groups each containing a plurality of contiguous strands, with at least one strand of each group lying on one side of the set of weft strands, and at least one other strand of each group lying on the other side of the set of weft strands in contiguous superimposed relationship with the other strand of the group on the other side of the weft strands. The strands may be composed of glass (suitably E-type glass), carbon, aramid, or nylon. As noted above, however, the use of glass fibers in cementitious materials can be difficult because of the susceptibility of glass fibers to alkaline attack in Portland cement. In addition, others of the fibers disclosed by the patent have individual disadvantages such as the relatively high cost of carbon, notwithstanding its exceptional strength and resistance to alkaline attack in concrete.
Thus, there is a need for improved structural members adapted to reinforce a variety of products. For example, there continues to be a need for a structural reinforcement member for concrete structures which accomplishes the reinforcement or increases material properties of the concrete structure without being subject to corrosion or attack. Such a structural reinforcement member would preferably not only be resistant to corrosion or attack, but would also be relatively inexpensive. There also remains a need for methods to reinforce products using these structural members.
It is an object of the invention to overcome the deficiencies of the prior art as noted. A more particular object of this invention is to provide a structural member adapted to effectively reinforce a variety of different products, including relatively thin walled concrete panels. A further object of the invention is to provide methods for utilizing the structural member adapted to reinforce a product, and for efficiently producing the structural member.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the present invention are achieved by the reinforcing grid of the present invention which advantageously includes fibers of both a first type and a second type. The first type of fibers have a strength sufficient to reinforce the hardenable structural material, such as concrete, after hardening. The first type of fibers also have a higher resistance to degradation in the hardenable material than the second type of fibers. As such, the first type of fibers will continue to reinforce the hardened material in the event the fibers of the second type become corroded in the hardened material. Consequently, a less expensive type of fiber can be used as the second type of fiber and can corrode in the hardenable material without concern for the strength of the hardened structural product.
More particularly, the present invention includes a structural member for reinforcing a product formed of a hardenable, structural material after hardening of the material. The hardenable material can be conventional concrete, asphalt or polymer concrete. The structural member is in the form of a reinforcing grid and includes a set of warp strands wherein at least some of the strands are spaced apart. The warp strands are formed of fibers of at least one of the first type of fibers and the second type of fibers. As noted above, the first type of fibers have a strength sufficient to reinforce the hardenable material after hardening and a higher resistance to degradation in the hardenable material than the second type of fibers. According to one embodiment of the invention, the fibers of the first type comprise carbon fibers and the fibers of the second type comprise glass fibers. The carbon fibers have a strength sufficient to reinforce the hardenable material after hardening. Conversely, the glass fibers may corrode in the hardenable material, but are much less expensive than the carbon fibers.
The grid also includes a set of weft strands wherein at least some of the strands are spaced apart and are disposed at substantially right angles to the set of warp strands to define an open structure through which the hardenable material can pass before hardening. The weft strands are also formed of at least one of the first and second types of fibers such that the gridwork is partially formed of fibers of the first type which will continue to reinforce the hardened material in the event the fibers of the second type become corroded in the hardened material.
The set of warp strands can be separated into groups each containing a plurality of contiguous strands, with at least one strand of each group lying on one side of the set of weft strands and at least one other strand of each group lying on the other side of the set of weft strands. In particular, the warp strand lying on one side of the weft strands can comprise fibers of the first type and the warp strand lying on the other side of the weft strands can comprise fibers of the second type.
The grid according to one embodiment is impregnated substantially throughout with a thermosettable B-stage resin so as to interlock the strands at the crossover points of the strands and maintain the grid in a semi-flexible state which permits the grid to conform to the shape of the product to be reinforced. The thermoset resin may further be fully cured before use so as to interlock the strands at the crossover points of the strands and maintain the grid in a relatively rigid state.
One particularly useful application of the reinforcing grid is in thin wall products made of concrete. The grid advantageously allows the thin wall panel to have a thickness of less than about three inches. Associated methods also form a part of the invention.
The present invention thus provides a reinforcing member for concrete and asphalt which is both strong and relatively inexpensive. The carbon fibers of the first type provide the necessary strength to reinforce the hardenable material after it is hardened, whereas the glass fibers of the second type provide structure to the reinforcing grid before it is embedded in the hardenable material. Because of the durability and strength of the fibers of the first type, the fibers of the second type can be less expensive and concerns about corrosion of these fibers are obviated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a structural reinforcement member comprising one embodiment of the present invention.
FIG. 2 is a perspective view of a structural member adapted to reinforce a product comprising another embodiment of the present invention.
FIG. 3 is a perspective view of a structural member adapted to reinforce a product comprising another embodiment of the present invention.
FIG. 4 is a perspective view of an embodiment of a structural member of the present invention and which is adapted for use with metal or fiber glass rebars.
FIG. 5 is a cross sectional view of a thin walled concrete panel structure reinforced with a reinforcing grid according to the invention.
FIG. 5A is a greatly enlarged cross sectional view of the thin walled panel according to FIG. 5 and illustrating the reinforcing grid in more detail.
FIG. 6 is a perspective view of another embodiment of the structural reinforcing member according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail hereinafter by reference to the accompanying drawings. The invention is not intended to be limited to the embodiments described; rather, this detailed description is included to enable any person skilled in the art to make and use the invention.
In FIG. 1, a structural reinforcement member for reinforcing a product is shown which embodies the present invention. This structural member can be used to reinforce products formed of a hardenable structural material, such as concrete or asphalt, by placing the structural member in the hardenable material before hardening of the material. The structural member comprises a gridwork 10 comprising a set of warp strands 12 and a set of weft strands 14 disposed at substantially right angles to each other. Each of the strands comprises a plurality of continuous filaments, composed for example of glass (an E-type glass is particularly suitable), carbon, aramid, or nylon fibers.
Advantageously, some of the strands 12 , 14 of the grid are formed of a first type 11 of fibers and some of the other strands of the grid are formed of a second type 16 of fibers, as can be seen in FIGS. 1 and 6 which illustrate preferred embodiments. The first type 11 of fibers have a sufficiently high tensile modulus and stiffness to reinforce concrete structures after hardening of the concrete. The first type 11 of fibers also are resistant to alkaline attack and corrosion from the concrete over time. The use of carbon fibers as the first type of fibers has been found to be particularly useful.
The fibers of the second type 16 are, according to a preferred embodiment, formed of glass. The glass fibers are not as strong as the carbon fibers and are subject to alkaline attack and corrosion from the concrete material. In fact, glass fibers in concrete structures have been found to break up and lose all of the original strength of the fibers over a period of several years. However, glass fibers are significantly less expensive than carbon fibers. With the present invention, the advantages of both types of fibers are retained while the disadvantages are minimized. In particular, the glass fibers 16 may only serve a reinforcing function during handling of the gridwork 10 prior to being surrounded by the concrete or during the subsequent hardening process of the concrete. It may be the case that the glass fibers are sufficient to reinforce the concrete if the fibers are not attacked by the concrete. However, even if the glass fibers 16 subsequently corrode and lose all of their strength, the carbon fibers 11 will remain to reinforce the concrete. On the other hand, the use of a reinforcing grid 10 formed only partially of carbon fibers is much less expensive than a reinforcing grid formed entirely of carbon fibers.
The first and second types of fibers are not necessarily carbon fibers and glass fibers, however, and these fibers may comprise other compositions as noted above. To optimize performance of the glass fibers, they can be sized with a coating (e.g., silane) which has been shown to help resist the effects of alkali attack and also give excellent compatibility with the thermoset resin discussed below. The fibers of the grid may, alternatively or additionally, be coated with rubber (such as styrene butadiene rubber latex) and the like to minimize corrosion of the glass fibers. In addition, the reinforcing grid according to the present invention is not limited to use in concrete structures and can be used in other products such as asphalt roadways where the fibers can be subjected to other kinds of corrosive effects such as exposure to rainwater having a high concentration of road salt.
The set of warp strands 12 is separated into groups 13 , each containing two contiguous strands in the illustrated embodiments. The set of weft strands 14 is separated into groups 15 , each containing several contiguous strands in the illustrated embodiments of FIGS. 2, 3 and 6 , although one of ordinary skill in the art would recognize that, as with the warp strands, each group may comprise only one strand. For example, FIG. 1 illustrates an embodiment where individual weft strands are separated from each other. The groups of strands of each set are spaced apart from each other so as to define an open structure. Also, it will be noted that in the illustrated embodiments, one strand of each group of the warp strands 13 lies on one side of the set of weft strands, and the other strand of each group of the warp strands 13 lies on the other side of the weft strands in a contiguous superimposed relationship. Thus, the sets of strands are non-interlaced. Also, the resulting superimposition of the warp strands achieves a “pinching or encapsulation” effect of the strands in the weft direction creating a mechanical and chemical bond at the crossover points.
The first type 11 and second types 16 of fibers can have various arrangements in the grid. For example the warp strands 12 or groups of warp strands 13 can alternate between fibers of the first type 11 and fibers of the second type 16 , as illustrated in FIG. 1 . Similarly, the weft strands 14 or groups of weft strands 15 can alternate between fibers of the first type 11 and fibers of the second type 16 . All of the strands in the weft direction may be comprised of fibers of one of the two types. Alternatively, all of the strands in the warp direction may be comprised of fibers of one of the two types. It is even possible to include additional fibers not of the first or second types in either or both directions to achieve other advantages.
The particular embodiment illustrated in FIG. 6 includes one strand of carbon fibers 11 after every three groups of strands of glass fibers 16 , in both the warp direction and the weft direction, such that every fourth strand is formed at least partly of carbon fibers. It is currently believed that a maximum spacing between neighboring carbon fiber strands is on the order of 2-2½ inches, although this spacing is dependent on a variety of factors, as would be appreciated by one of ordinary skill in the art. The glass fibers 16 are type 1715 available from PPG having a yield of 433 yards per pound and are arranged in bundles of two strands in each group. As explained above, the two warp strands 12 of each group 13 are disposed on either side of the weft strands 14 . The strands of carbon fibers 11 can be formed of 48K tows (each having approximately 48,000 individual filaments) having a yield of 425 feet per pound. The carbon fibers 11 can also be supplied in 3K, 6K, 12K and 24K tows although, as would be appreciated by one of ordinary skill in the art, the larger fiber tows are sometimes more economical than the smaller fiber tows.
The embodiment illustrated in FIG. 1 includes weft strands 14 which are formed entirely of glass fibers 16 and warp strands 12 which include both carbon fibers 11 and glass fibers 16 . The groups of warp strands 13 each comprise a pair of strands positioned one on either side of the weft strands 14 as discussed above. However, the groups of warp strands 13 alternate between groups where both of the warp strands are formed of glass fibers and groups where one of the strands comprises carbon fibers and the other comprises glass fibers. The carbon fiber strands 11 are all positioned on the same side of the weft strands 14 such that every alternating warp group 13 has a carbon strand on one side and a glass fiber strand on the other side. Accordingly, because the carbon fiber strands are so much stronger than the glass fiber strands, the glass fiber warp strands may function primarily to tie the glass weft strands to the carbon warp strands. Every alternating warp group 13 may also have carbon fiber strands 11 on both sides of the weft strands 14 , which provides a high long term “crossover bond strength” at the intersections of the warp and weft strands.
The gridwork 10 may be impregnated substantially throughout with a thermosettable B-stage resin so as to interlock the strands at their crossover points and maintain the gridwork in a semi-flexible state which permits the gridwork to conform to the shape of the product to be reinforced. The gridwork is designed to be incorporated into a finished product such that the material is conformed to the shape or the functionality of the end-use product and then cured to form a structural composite. The ability of the gridwork to be conformed to the shape of the product allows the member to be cured by the inherent heat that is applied or generated in the ultimate construction of the finished product. For example, in the case of laying hot asphalt in paving roads or using hot asphalt for roofing systems, the thermosettable B-stage resin impregnated into the gridwork would be cured by the heat of the hot asphalt as used in these processes. The resin would be selected for impregnation into the grid such that it would cure by subjecting it to the hot asphalt at a predetermined temperature. Heat can be applied to cure or partially cure the grid before incorporation into concrete structures.
The crossover of the strands can form openings of various shapes including square or rectangular which can range from ½ to 6 inches in grids such as that shown in FIG. 1 . FIG. 1 shows a square opening with dimensions of one inch in the warp direction and one inch in the weft direction. The size of the glass fiber bundles in each strand can vary. A range of glass strands with a yield from 1800 yards per pound up to 56 yards per pound can be used and, in particular, strands having yields of 247 yards per pound and 433 yards per pound.
The gridwork 10 may be constructed using a conventional machine, such as the web production machine disclosed in U.S. Pat. No. 4,242,779 to Curinier et al., the disclosure of which is expressly incorporated by reference herein.
A B-stage resin is a thermosetting type resin which has been thermally reactive beyond the A-stage so that the product has only partial solubility in common solvents and is not fully fusible even at 150°-180° F. Suitable resins include epoxy, phenolic, melamine, vinyl ester, cross linkable PVC, and isophthalic polyester. A common characteristic of all of these resins is that they are of the thermoset family, in that they will cross link into a rigid composite, which when fully cured cannot be resoftened and remolded. They also have the capability to be “B-staged”, in which they are not fully cured and can be softened and reshaped either to conform to the shape of the end use product or corrugated into a three dimensional shape as described below. A preferred embodiment uses urethane epoxy resin applied to the flat open mesh scrim by means of a water emulsion.
A preferred method of producing the gridwork 10 includes applying the resin in a “dip” operation, as discussed in U.S. Pat. No. 5,836,715 which is incorporated herein by reference as noted above. In the “dip” operation, the resin in the bath is water emulsified with the water being evaporated by the subsequent nipping and heating operations. Resins which are capable of being “B-staged” as described above, are suitable, and the resins contemplated for this structural member are non-solvent based resins, and may or may not be water emulsified. Resins such as polyethylene or PPS may also be utilized. These resins would be applied in an emulsion type coating operation, and cured to a B-stage. Also, to a certain extent, the individual filaments themselves can be impregnated with the resin.
Impregnating the gridwork 10 with a thermosettable B-stage resin permits the gridwork to be semi-flexible and conform to the shape of the product to be reinforced, particularly with the application of heat. Once the gridwork is conformed to the shape of the product to be reinforced, the B-stage resin is cured to a thermoset state, providing upon cooling added rigidity and enhanced properties to the resulting product.
One of the advantages of the impregnated gridwork 10 is that it can be conformed to the shape of the product desired to be reinforced and cured in situ using the heat available in the normal manufacturing process, such as heated asphaltic concrete in asphaltic roadway construction. Alternatively, it may be cured by external heat, in which case it may be cured to a rigid state prior to incorporation into a finished product or supplemental heat can be applied after incorporation in the finished product, if desired.
Once cured, the gridwork is relatively rigid. This produces a structural member adapted to reinforce a product such as a pre-cast concrete part, base of asphalt overlay, etc. Such a rigid gridwork would be structurally composed of the same strand configurations and compositions as the flat grid-work impregnated with a B-stage resin, except that the B-stage resin has been advanced to a fully cured C-stage. The resulting rigid state of the gridwork provides added reinforcement to the product.
Another embodiment of the structural reinforcement member comprises a three-dimensional structural member as illustrated in FIG. 2 at 32 . The three-dimensional structural member 32 may be formed by starting with the flat gridwork 10 impregnated with a B-stage resin described above and processing it into a three-dimensional structure according to techniques described in the '715 patent. More particularly, the set of warp strands 12 is corrugated into alternating ridges and grooves, while the set of weft strands 14 remains substantially linear.
The three-dimensional structural member 32 can accommodate a variety of parameters and grid configurations differing according to varying needs of different applications such as in concrete and asphalt road construction. Grid height can be varied to accommodate restrictions of end products. For example, grids for concrete will generally have a greater height than grids for asphalt paving primarily because of the need to reinforce the greater thickness of a new concrete road as compared to asphalt overlays which are usually only 2-2½ inches thick. In a new asphalt road construction, where the thickness of the overlay might be 5-11 inches, grids of greater height would be provided. Generally, asphalt is applied in asphaltic paving in a plurality of layers each being 2-5 inches thick, and as such the preferred grid for asphalt reinforcement would have a height between ½ and 4 inches. Grids of varying width can also be provided, for example, grids up to seven feet are presently contemplated, yet no restriction is intended on grids beyond this width by way of this example.
The three-dimensional structural member 32 , with a thermosettable B-stage resin as described previously, permits the gridwork to be semi-flexible and conform to the shape of the product to be reinforced. Once the gridwork is conformed to the shape of the product to be reinforced, the B-stage resin would be cured providing added rigidity and enhanced properties to the resulting product. One of the advantages of the gridwork as disclosed in FIG. 2 is that it can be conformed to the shape of the product desired to be reinforced and cured in situ using either the heat available in the normal manufacturing process, such as heated asphaltic concrete in asphaltic roadway construction, or by heating from an external heat source. The structural member 32 could also be cured to a rigid state prior to incorporation into a finished product if desired. The gridwork could be cured thermally at a predetermined temperature depending on the particular resin.
The three-dimensional structural member 32 has many potential applications. A preferred embodiment is a method for fabricating a reinforced concrete or asphaltic roadway. Also, the three-dimensional gridwork can be used for reinforcing concrete structures in concrete precast slabs, for reinforcing double “T” concrete beams, concrete pipe, concrete wall panels, and for stabilization of aggregate bases such as rock aggregate used as a sub-base in road construction.
FIG. 3 shows another embodiment of a three-dimensional structural composite member 40 adapted to reinforce a product, and which embodies the present invention. This embodiment comprises a three-dimensional corrugated member 32 a which is similar to the member 32 as described above, but wherein the corrugations of the warp strands 12 a are inclined at about 45° angles, rather than substantially vertical as in the member 32 . Also, the number and placement of the weft groups 14 a is different. As illustrated, the member 32 a is used in conjunction with a generally flat gridwork 10 as described above. Specifically, the generally flat gridwork 10 is positioned to be coextensive with one of the planes of the three-dimensional gridwork.
The three dimensional composite member 40 can be impregnated with a B-stage resin as described above, or alternatively, it can be fully cured prior to incorporation into a product to be reinforced, such as Portland cement concrete products as further described below.
Another embodiment of the invention is illustrated in FIG. 4, and comprises a three dimensional structural reinforcement member 32 b comprising gridwork of a construction very similar to that illustrated in FIG. 2, and which comprises groups of warp strands 13 b and groups of weft strands 15 b disposed at right angles to each other. The member 32 b further includes specific positions 42 molded into the warp strands of the gridwork to allow steel or fiber glass rebars 44 to be placed in at least some of the grooves of the corrugations and so as to extend in the direction of the corrugations. In the preferred embodiment, these positions would allow the steel or fiber glass rebars 44 to be placed between the upper and lower surfaces defined by the corrugations, and thus for example approximately 1 inch from the foundation or surface upon which the corrugated grid structure was placed. After placing the steel or fiber glass rebars on these molded in positions 42 , additional steel rebars (not shown) could be placed at right angles to the original steel rebars and on top of them holding them in place by tying them to the “Z-axis” fibers of the composite corrugated gridwork. The main benefit to the “molding in” of the positions 42 into the corrugated composite gridwork is to allow the steel or fiber glass rebars to be placed a distance from the foundation or base upon which the corrugated gridwork is placed. In placing steel rebars conventionally in products such as bridge decks, it is common to use small plastic chairs in order to position the steel rebars so that they are not lying on the foundation, but are positioned approximately 1-2 inch up off of the foundation These separate chairs are not required with the embodiment of FIG. 4 .
Methods for Utilizing the Structural Reinforcement Member
The several embodiments of the structural reinforcement members as described above can be utilized in a variety of methods for reinforcing various products. One method involves providing the gridwork impregnated with a B-stage resin as described, applying the gridwork to the product in conforming relation, and then applying heat to the product so as to cure the resin and convert the same into a fully cured resin to thereby rigidify the gridwork and reinforce the product. Any product where the advantage of having a semi-rigid open reinforcement which could be cured in situ would be a potential application in which this method could be used. Therefore the embodiments contained herein by way of example do not limit such methods and uses.
The use of the flat grid and three-dimensional grid in conjunction, as shown in FIG. 3, would serve to unitize the three-dimensional composite grid in the direction of corrugation and to allow workers in the field to be able to better walk on the material as the concrete is being pumped through the grid structure to form the finished concrete road. The flat grid can be laid on top of the three-dimensional grid, and fastened with fastening means such as metal or plastic twist ties in order to better hold the flat grid structure to the top of the corrugated grid structure. Also, in concrete road construction a flat composite grid could be positioned beneath the three-dimensional corrugated grid structure to give added structural integrity to the three-dimensional structure.
The three-dimensional gridwork is versatile in allowing the contractor to tailor the amount of desired reinforcement in the concrete road by nesting the corrugated three-dimensional structures one on top of the other. This would still allow concrete flow through the openings in the grid structure, but would provide a means to increase the amount of reinforcement in the concrete.
The embodiments of the novel gridwork as described herein have a variety of uses, in addition to reinforcing roadway surfaces. For example, decayed telephone poles can be rehabilitate, with the heat mechanism for cure being a hot asphalt matrix or possibly additional external heat for full cure. Another embodiment of the invention comprises a method for fabricating reinforced concrete columns with better performance in seismic regions with the heat cure provided by an external heater or by a hot asphalt matrix overcoat.
The gridwork of the present invention, when fully cured as described above, is particularly useful in reinforcing a structure composed of a concrete material, such as Portland cement concrete. For example, in the case of new roadway construction, the foundation is prepared and the fully cured gridwork is placed upon the foundation. Thereafter, the liquid concrete is poured upon the foundation so as to immerse the gridwork, and upon the curing of the concrete, a reinforced concrete roadway is produced with the gridwork embedded therein.
Another concrete product utilizing the reinforcing grid 10 according to the present invention is illustrated in FIG. 5 . In certain applications, it is desirable to make concrete structures having thin wall panel sections 58 . For example, panels 58 which do not require extremely high strength, and/or panels which are reinforced with one or more ribs 60 , are sometimes thicker than desired because of the limitations on conventional steel reinforced concrete. As mentioned above, typically at least one inch of concrete thickness is needed on either side of the reinforcing steel to cover the steel sufficiently to ensure that corrosion of the steel will not lead to spalling of the concrete. However, with the structural member according to the present invention, the materials used for the reinforcing grid will not corrode in a manner which causes spalling of the covering concrete when the covering concrete is less than one inch in thickness. In addition, the reinforcing grid 10 has a total thickness significantly less than the thickness of conventional reinforcing steel. Accordingly, concrete panels 58 or sections of panels having a thickness of less than three inches, and even as thin as ¾ to 1 inch, can advantageously be made with the reinforcing grid according to the invention.
Another use for the present invention involves a method of reinforcing asphaltic roofing, either as a prefabricated single-ply sheeting or as a conventional built-up roofing. During formation of the roofing, the heat of the hot asphalt will cure the B-staged resin to the C-stage. The result is a stronger roofing that will resist sagging or deformation and rupture by walking or rolling traffic on the roofing.
In the drawings and the specification, there have been set forth preferred embodiments of the invention and, although specific terms are employed, the terms are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being set forth in the following claims.
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A reinforcing grid which advantageously includes fibers of both a first type and a second type is provided. The first type of fibers have a strength sufficient to reinforce the hardenable structural material, such as concrete, after hardening. The first type of fibers also have a higher resistance to degradation in the hardenable material than the second type of fibers. As such, the first type of fibers will continue to reinforce the hardened material in the event the fibers of the second type become corroded in the hardened material. Consequently, a less expensive type of fiber can be used as the second type of fiber and can corrode in the hardenable material without concern for the strength of the hardened structural product. According to one embodiment, the first type of fibers comprises carbon fibers and the second type of fibers comprises glass fibers.
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This is a continuation of application Ser. No. 08/517,438, filed Aug. 21, 1995, now U.S. Pat. No. 5,844,657 the contents of which are herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a progressive power (multi-focal) lens for eyeglasses, in which the surface power continuously changes from a distance portion to a near portion. In particular, the present invention relates to a progressive power lens which is provided on a peripheral edge thereof with a rim surface portion whose width is reduced to provide an increased effective surface area of the lens. The present invention also relates to a mold which produce such a progressive power lens.
2. Description of Related Art
In a known process of producing a plastic lens for eyeglasses, a monomeric material 54 in liquid state is introduced and heated in a cavity defined between molds 51 , 52 and a gasket 53 to polymerize the same, so that a lens 50 of a solid polymer can be obtained, as shown in FIG. 16 .
The gasket 53 is made of a relatively elastically deformable material to confine the monomer 54 in the mold cavity defined between the molds 51 and 52 and to absorb a change in volume due to the polymerization from a monomer to a polymer.
The mold to produce a plastic single focal lens or a plastic multi-focus lens having a distance portion and a near portion separate from the distance portion, or a semi-product thereof, is usually provided with a spherical mold surface, and hence, the thickness T of the gasket 53 to be used is constant over the entire periphery of the lens. However, for a mold to produce an astigmatic power lens as a final product, a gasket whose thickness varies in accordance with a shape of a toric lens surface must be used. To reduce the number of kinds of gaskets to be prepared, the toric surfaces are systematized.
In the mold for the progressive power lens, the shape of the surface thereof on the progressive surface (progressive side) is a complex aspherical surface. Moreover, for example, in the arrangement of the mold and the gaskets as shown in FIG. 16, the thickness of the gaskets are not uniform. In particular, in a mold for the progressive power lens whose optical center is deviated from the center of the circle (diameter) of the lens, the change in the thickness of the gasket, along the outer periphery thereof, is much more complicated.
Assuming that, in coordinate systems as shown in FIGS. 17 and 18 in which the diameters of the lens 50 and the molds 51 , 52 are indicated by 55 and 56 , respectively, and coordinates Z1 and Z2 (FIG. 18) of both surfaces of the lens 50 at an optional angle θ are represented by the Z-axis, a graph as shown in FIG. 19 is obtained. The distance between Z1 and Z2, at an optional angle θ, corresponds to the thickness T of the gasket at the angle θ.
A progressive power lens includes a base curve representing the power of the distance portion and the power of the near portion in combination (note that a difference between the power of the distance portion and the power of the near portion is referred to as “addition power”). There are more than 100 combinations of the base curve and the power of the near portion for one lens system (product). It is therefore impractical to prepare many gaskets corresponding to these combinations in view of the production cost or stocking thereof.
To this end, the mold 51 , which forms the progressive surface of the lens, is ground flat at the peripheral portion, so that the rim surface portion (flat surface portion or non-progressive focus area) 58 , which does not serve as a progressive surface (effective surface), is formed at the periphery of the lens, as shown in FIG. 20 . Consequently, the gasket has a uniform thickness regardless of the angle θ.
Thus, the thickness T of the gasket is uniformly constant over the entire periphery of the lens as seen in FIG. 21, and the gasket can be commonly used with various kinds of progressive surfaces having different base curves and different addition powers in combination.
FIG. 22 shows a mold used to form the progressive surface (effective surface) of a progressive power lens, using the gasket having the rim surface 58 . As can be seen in FIG. 22, the rim surface 58 is formed around (on upper and lower sides of) the progressive surface (effective surface) 57 . The diameter of the effective progressive surface 57 is reduced in the vertical direction due to the presence of the rim surface portion 58 , but no serious problem is practically caused by the reduction of the effective diameter as, in general, the diameter of a frame for eyeglasses in the vertical direction is smaller than the diameter thereof in the horizontal direction.
However, to respond to the requirement to make the eyeglasses thinner and lighter, the radius of the base curve of the progressive power lens has recently been increased. In particular, in the lens having a large negative power, if the flat rim surface 58 is provided, the reduction of the effective diameter in the vertical direction is not acceptable.
FIG. 23 shows an example of a known progressive power lens which is used to correct a highly myopic presbyopia, wherein the addition power is about 3.00 D (diopter), and the surface power of the distance portion is around −7.00 D to −10.00 D (diopter). The effective progressive surface spreads over the whole lens diameter (=70 Φmm) in the horizontal direction, but is reduced in the vertical direction by the rim surface portions 58 each having a width of 8.2 mm, which are formed on the upper and lower sides of the progressive surface 57 . The average surface power at the distance reference point 59 is 0.12 D and the refractive index of the blank material is 1.6. The distance reference point refers to a point on the front surface of the lens at which the corrective power for the distance portion shall apply.
FIG. 25 shows vertical and horizontal sections 60 and 61 which define the progressive surface portion 57 of a progressive power lens in an overlapped state. For clarity, in the drawings, the dimension in the longitudinal direction, only, is enlarged. The vertical and horizontal section lines of the rim surface 58 are indicated by dotted and dashed lines. The intersecting points of the progressive surface and the rim surface in the vertical section are indicated at 64 and 64 ′, and the corresponding intersecting points in the horizontal section are indicated by 65 and 65 ′, respectively. The symbol φ designates the angle defined by lines normal to the rim surface and the progressive surface. The parenthesized numerals represent the angle θ in FIG. 17 . “Wa” designates the width of the upper rim surface portion, and “Wb” the width of the lower rim surface portion, respectively. The progressive surface is inclined at an appropriate angle so that the width Wa is identical to the width Wb.
FIG. 24 shows another example of a known progressive power lens which is used to correct a myopic presbyopia, wherein the addition power is about 3.00 D (diopter), and the surface power of the distance portion is around −3.00 D to −6.00 D (diopter). The effective progressive surface spreads over the whole lens diameter (=75 Φmm) in the horizontal direction but is reduced in the vertical direction by the rim surface portions 58 each having a width of 4.1 mm, which are formed on the upper and lower sides of the progressive surface 57 . The average surface power at the distance reference point 59 is 2.04 D and the refractive index of the blank material is 1.6.
FIG. 26, which corresponds to FIG. 25, shows vertical and horizontal sections 60 and 61 which define the progressive surface portion 57 of a progressive power lens in an overlapped state. FIGS. 25 and 26 show that the widths Wa and Wb of the upper and lower rim surface portions increase as the curvature of the base curve decreases, so long as the addition power is identical.
In the first example of a known progressive power lens, in which the curvature of the base curve is small, the angle φ, defined by the progressive surface and the rim surface at the boundary between the progressive surface 57 and the rim surface 58 , as shown in FIG. 25, is small on average. Consequently, the widths Wa and Wb, of the rim surfaces that correspond to the difference in the position between the intersecting points 64 and 64 ′ (in the vertical section) and the intersecting points 65 and 65 ′ (in the horizontal section) are increased.
In the two examples of prior art mentioned above, assuming that the angle φ is graphed as a function of the angle θ, the graphs of examples 1 and 2 are shown in FIGS. 27 and 28, respectively. The mean value AVG(φ) of the angle φ and the standard deviation STD(φ) are defined as follows: AVG ( φ ) = ∫ 0 360 φ ( θ ) θ / 360 STD ( φ ) = [ ∫ 0 360 { φ ( θ ) - AVG ( φ ) } 2 θ / 360 ] 1 2
The ratio between AVG(φ) and STD(φ) is an index (measure) which represents the magnitude of the change in the angle defined between the progressive surface and the rim surface. The index is 0.28 in the first example and 0.13 in the second example, respectively.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a progressive power lens in which the width of the rim surface can be decreased even when the curvature of the base curve is small.
Another object of the p resent invention is to provide a mold to produce such a progressive power lens.
Namely, according to the basic concept of the present invention, the angle φ, defined between the progressive surface and the rim surface, is set to be a relatively large value to lower the ratio of STD(φ)/AVG(φ), to reduce the width of the rim surface. Since the shape of the progressive surface is determined in accordance with requirements of optical performance and ornamental appearance, the rim surface, which is a planar surface in the prior art, is a curved surface in the present invention. The curved surface can be a conical surface, a toric surface, a spherical surface, a cylindrical surface, or a toroidal surface, (such as a doughnut-shaped surface), etc. The curved surface is oriented to project in the direction opposite to the projecting direction of the progressive surface.
According to the present invention, there is provided a progressive power lens having an effective surface, including a progressive surface portion which progressively varies the power, and a peripheral rim surface, which does not function as an effective surface, and which is provided to surround the effective surface. The rim surface portion is a curved surface.
In an embodiment of the invention, a progressive power lens satisfies the following relationship:
Df≦3 (1)
STD (φ) /AVG (φ)≦0.15 (2)
with
STD(φ) represents the standard deviation of φ over the entire circumferential length of the lens;
AVG(φ) represents a mean value of φ over the entire circumferential length of the lens;
Df (diopter) represents an average surface power at a distance reference point of the progressive surface portion; and,
φ (degree) stands for the angle defined by the progressive surface portion and the rim surface portion at a boundary therebetween.
Preferably, the progressive power lens further satisfies the following relationships:
Df≦2 (3)
STD (φ) /AVG (φ)≦0.1 (4)
If part of the rim surface is a spherical surface, the spherical surface is oriented to project in the direction opposite to the projecting direction of the progressive surface portion.
In other words, the surface power Ds (diopter) of the spherical surface and the average surface power Df (diopter) at the distance reference point of the progressive surface portion have different signs. Preferably, the progressive power lens satisfies the following relationships:
Df≦3 (5)
Ds≦Df− 2 (6)
More preferably, the lens meets the following relationships:
Df≦2 (7)
Ds≦Df− 3 (8)
A part of the rim surface can be made of a toric surface or cylindrical surface. Assuming that the surface powers of the toric or cylindrical surface in the vertical direction and in the horizontal direction are Dv (diopter) and Dh (diopter), respectively, it is preferable that Dv is equal to or greater than Dh, i.e.,
Dh≦Dv (9)
If a part of the rim surface is made of a toric surface or a cylindrical surface, the cylindrical surface is oriented to project in the direction opposite to the projecting direction of the progressive surface portion. Preferably, the progressive power lens satisfies the following relationships:
Df≦3 (10)
( Dh+Dv )/2≦ Df− 2 (11)
A part of the rim surface can be a toroidal surface, including a doughnut-shaped surface.
If a part of the rim surface is a conical surface, the apex thereof is oriented in the direction opposite to the projecting direction of the progressive surface portion. In this case, the progressive power lens preferably satisfies the following relationship:
Df≦3 (12)
Ω≦170 (13)
with
Df (diopter) represents an average surface power at a distance reference point of the progressive surface portion; and,
Ω (degree) represents an apex angle of the conical surface.
The requirement of Df≦3 in the formulae (1), (5), (10) and (12) refers to the application of the present invention to a progressive power lens in which the curvature of the base curve is relatively small. If the curvature of the base curve is larger, the width of the rim surface is originally so small that no improvement is necessary.
If the lens meets the requirements defined by the formulae (2), (6), (11) and (13), a reduction in the width of the rim surface can be expected to some extent. However, if the lens does not meet these formulae, no reduction in the width of the rim surface can be obtained.
Formulae (3), (7) and (4), (8) are directed to further increase the value of the angle φ in order to satisfactorily reduce the width of the rim surface, for the progressive surface whose curvature of the base curve is smaller. However, if the angle φ is too large, the workability of the lens is remarkably worsened, and a prism error can be easily caused. Consequently, the angle φ should not be too large.
According to another aspect of the present invention, there is also provided a mold which is used to produce a progressive power lens. A progressive surface forming portion forms a progressive surface portion of the lens. A rim surface forming portion forms a rim surface portion of the lens, (which does not function as a progressive surface). The rim surface forming portion is a curved surface. The above-mentioned requirements can be equally applied to the curved surface.
The present disclosure relates to subject matter contained in Japanese Patent Application No.06-197019 (filed on Aug. 22, 1994) which is expressly incorporated herein by reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described below in detail with reference to the accompanying drawings, in which:
FIG. 1 is a schematic view of curves representing the shape of a progressive power lens on the progressive surface thereof in the horizontal and vertical sections, and a curve representing the shape of a rim surface, in an overlapped state, according to a first embodiment of the present invention;
FIG. 2 is a front elevational view of a progressive power lens, according to a first embodiment of the present invention;
FIG. 3 is a diagram showing a change in the angle between the progressive surface and the angle rim surface in a first embodiment of the present invention;
FIG. 4 is a schematic view to explain the process to produce a rim surface, according to a first embodiment of the present invention;
FIG. 5 is a front elevational view of a progressive power lens, according to a second embodiment of the present invention;
FIG. 6 is a front elevational view of a progressive power lens, according to a third embodiment of the present invention;
FIG. 7 is a view similar to FIG. 1, according to a fourth embodiment of the present invention;
FIG. 8 is a front elevational view of a progressive power lens, according to a fourth embodiment of the present invention;
FIG. 9 is a view similar to FIG. 1, according to a fifth embodiment of the present invention;
FIG. 10 is a front elevational view of a progressive power lens, according to a fifth embodiment of the present invention;
FIG. 11 is a view similar to FIG. 1, according to a sixth embodiment of the present invention;
FIG. 12 is a front elevational view of a progressive power lens, according to a sixth embodiment of the present invention;
FIG. 13 is a schematic view to explain the process to produce a rim surface, according to a sixth embodiment of the present invention;
FIG. 14 is a schematic view to explain the process to produce a rim surface which is in the form of a toroidal surface;
FIG. 15 a is a schematic view of a smoothly continuous boundary portion between a progressive surface and a non-progressive surface (rim surface);
FIG. 15 b is an enlarged view of a circled portion in FIG. 15 a;
FIG. 16 is a schematic view showing a method for producing a known plastic lens;
FIGS. 17 and 18 are coordinates of a lens diameter and diameters of molds;
FIG. 19 is a graph showing the thickness of a gasket, wherein said gasket is used for forming a progressive power lens having no rim surface.
FIG. 20 is a schematic view to explain the process to produce a progressive surface with a flat rim surface according to the prior art;
FIG. 21 is a graph showing the uniform thickness of a gasket, wherein said gasket is used for forming a progressive power lens with a rim surface;
FIG. 22 is a front elevational view of a mold for forming a progressive power lens having a rim surface;
FIG. 23 is a front elevational view of a first known progressive power lens;
FIG. 24 is a front elevational view of a second known progressive power lens;
FIG. 25 is an explanatory view of curves representing the shape of a first known progressive power lens on the progressive surface in the horizontal and vertical sections, and a rim surface shown in an overlapped state;
FIG. 26 is a view similar to FIG. 25 for a second known progressive power lens;
FIG. 27 is a graph showing a change in the angle between the progressive surface and the rim surface in a first known progressive power lens; and,
FIG. 28 is a graph showing a change in the angle between the progressive surface and the rim surface in a second known progressive power lens.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show a first embodiment of the present invention.
In FIG. 1, the progressive power lens 50 whose specification is the same as that of the first known progressive power lens mentioned above is used. In FIGS. 1 and 2, in which only the lateral dimension is enlarged as in FIG. 25, the vertical section 60 and the horizontal section 61 that define the progressive surface (effective surface) 57 are shown in an overlapped state. FIG. 2 shows a front elevational view of a progressive power lens. In the first embodiment, the rim surface 58 defines a part of a spherical surface of −3 D (diopter). The vertical and horizontal section lines 62 and 63 of the rim surface overlap and are indicated by a dotted and dashed line. The width of the rim surface is reduced from 8.2 mm (prior art) to 2.7 mm, which can be practically negligible.
In FIGS. 1 and 2, φ designates the angle defined between the progressive surface 57 and the rim surface 58 as in the prior art, and the parenthesized numerals designate the angle θ in FIG. 17 .
FIG. 3 shows an aφ−θ diagram of a progressive power lens, corresponding to FIG. 27 . Comparing FIG. 3 and FIG. 27, it can be understood that the values of φ in the illustrated embodiment are larger than those in FIG. 27 by around 10 degrees. Namely, the value of AVG(φ) is increased in the present invention (it can be considered that the values of STD(φ) are substantially the same as those in FIG. 27 ). Consequently, the coefficient of change (ratio) defined by STD(φ)/AVG(φ) is reduced from 0.28 (prior art) to 0.09.
To obtain the rim surface, the peripheral edge of the mold 51 , for forming the progressive surface, is first ground by a coarse grinder 67 , which is normally used to form a spherical surface, and then polished. To reduce the width of the rim surface, it is necessary to increase the curvature of the spherical surface in the direction opposite to the curvature of the progressive surface. Nevertheless, if the curvature is excessively increased, it becomes difficult to precisely work or grind the rim surface, as a serious prism error can be caused due to a misfit of the gasket and the molds. Accordingly, the width of the rim surface is determined taking into account the workability and the prism error, as in a second embodiment of the present invention, discussed below.
FIG. 5 is a front elevational view of a progressive power lens according to a second embodiment of the present invention. The progressive power lens used in the second embodiment is the same as that of the first embodiment. The rim surface 58 is a part of a spherical surface of −2 D (diopter). Due to the restriction of the curvature of the rim surface, the width of the rim surface is reduced from 8.2 mm (prior art) to 3.4 mm, which is practically negligible. Moreover, not only can the workability of the rim surface be enhanced, but there is also little adverse influence on the prism error.
FIG. 6 shows a third embodiment of the present invention. In the third embodiment, the curvature of the base curve is not as small as the prior art (first known progressive power lens). Consequently, even if the rim surface 56 is made of a part of a spherical surface of −2 D (diopter), the width of the rim surface can be reduced to be 2.6 mm.
In general, the curve of the progressive surface is more sharp in the vertical section than in the horizontal section. Consequently, the width of the rim surface can be reduced by providing a difference in the curvature between the horizontal section and the vertical section.
FIGS. 7 and 8 show a fourth embodiment of the present invention. There is provided a difference in curvature between the horizontal section 63 and the vertical section 62 of the rim surface. FIG. 7 shows a view similar to FIG. 1, in which the vertical and horizontal sections 60 and 62 of the progressive power lens 50 and the vertical and horizontal sections 62 and 63 of the rim surface overlap. FIG. 8 is a front elevational view of a progressive power lens according to the fourth embodiment. In this embodiment, the surface power Dh of the horizontal section 63 is −2.5 D (diopter), and the surface power Dv of the vertical section 62 is a part of a toric surface of −2 D. With this arrangement, the width of the rim surface is reduced to 0.9 mm. To produce a mold for forming the progressive surface having a rim surface defined by a toric surface, the rim surface 58 is first coarsely ground by a toric generator and is then polished.
FIGS. 9 and 10 show a fifth embodiment of the present invention, in which the curvature of the base curve is not as small as the prior art (first known progressive power lens). In this embodiment, it is not necessary for the rim surface 58 to be made of a toric surface. Namely, the rim surface is defined by a part of a cylindrical surface in which the surface power Dh of the horizontal section 63 is −0.5 D and the surface power Dv of the vertical section 62 is 0D. The width of the rim surface is therefore reduced to 1.3 mm.
FIGS. 11 and 12 show a sixth embodiment of the present invention. In the sixth embodiment, the rim surface is defined by a part of a conical surface whose apex angle is 160 degrees. The direction of the apex 68 of the cone is opposite to the direction of the convex progressive surface 57 . The width of the rim surface is reduced to 2.6 mm. The apex angle of the conical surface can be selected to be an appropriate value smaller than about 170 degrees. If the apex angle exceeds 170 degrees, there is no remarkable difference between the present invention and the prior art (180 degrees).
FIG. 13 shows an example of a rim surface which has a partial conical surface. The conical grinder can be used instead of the coarse grinder 67 shown in FIG. 4 . Alternatively, a cylindrical, disc-shaped, or cup-shaped grinder 69 can be used to grind the peripheral edge of the mold, as shown in FIG. 13 .
As shown in FIG. 14, an hourglass-shaped or sheave-shaped grinder 70 forms a rim surface with a partial toroidal surface, including a doughnut-shaped surface. In this case, the technical advantage that the width of the rim surface is reduced can be equally obtained.
Numerical data of the progressive power lens according to the first to sixth embodiments of the present invention and the two prior art examples are shown in Table 1 below. Note that in all the lenses, the addition power is 3.00 D and the refractive index of the blank material is 1.6.
TABLE 1
average
surface
form of
width
whole
power
non-
of
lens
at distance
progressive
the
dia-
reference
surface
rim
meter
point
(rim
STD (φ)/
surface
(mm)
(Df)
surface)
AVG (φ)
(mm)
Example 1
70
0.12
plane
0.28
8.2
(Ds = 0)
Example 2
75
2.04
plane
0.13
4.1
(Ds = 0)
Embodiment 1
70
0.12
spherical
0.09
2.7
(Ds = −3)
Embodiment 2
70
0.12
spherical
0.11
3.4
(Ds = −2)
Embodiment 3
75
2.04
spherical
0.08
2.6
(Ds = −2)
Embodiment 4
70
0.12
toric*
0.10
0.9
Embodiment 5
75
2.04
cylindrical**
0.11
1.3
Embodiment 6
70
0.12
conical***
0.09
2.6
*Dh = −2.5, Dv = −2
**Dh = −0.5 Dv = 0
***Ω =160
Although the progressive surface and the rim surface (non-progressive surface) are clearly separated by the boundary 66 in the above discussion, the present invention can be equally applied when the boundary is a smooth boundary 66 which is smoothed by a grinder, etc. In this case, the boundary is defined by an intersecting line which is obtained by extrapolating the progressive surface and the rim surface. The angle formed between the progressive surface and the rim surface refers to that for the extrapolated progressive surface and the rim surface.
As can be seen from the above discussion, according to the present invention, a progressive power lens which is provided on the peripheral edge thereof with a rim surface portion (non-progressive surface) in which the width of the rim surface is reduced even if the curvature of the base curve of the progressive surface is small, can be provided. Also, according to the present invention, a mold to produce such a progressive power lens can be easily provided.
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A progressive power lens has an effective surface including a progressive surface portion which progressively varies the power, and a peripheral rim surface portion which does not function as an effective surface and which is provided to surround the progressive surface portion. The rim surface portion is made of a curved surface. The invention is also directed to a mold which is used to produce a progressive power lens. The mold includes a progressive surface which progressively varies the power and a rim surface forming portion which forms a rim surface portion of the lens which does not function as a progressive surface. The rim surface forming portion is made of a curved surface.
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FIELD OF THE INVENTION
This invention relates to a method of completing a well that penetrates a subtertranean formation and more particularly, relates to a well completion technique for controlling the production of sand from a formation where high temperatures are encountered.
BACKGROUND OF THE INVENTION
In the completion of wells drilled into the earth, a string of casing is normally run into the well and a cement slurry is flowed into the annulus between the casing string and the wall of the well. The cement slurry is allowed to set and form a cement sheath which bonds the string of casing to the wall of the well. Perforations are provided through the casing and cement sheath adjacent the subsurface formation.
Fluids, such as oil or gas, are produced through these perforations into the well. These produced fluids may carry entrained therein sand, particularly when the subsurface formation is an unconsolidated formation. Produced sand is undesirable for many reasons. It is abrasive to components found within the well, such as tubing, pumps, and valves, and must be removed from the produced fluids at the surface. Further, the produced sand may partially or completely clog the well, substantially inhibiting production, thereby making necessary an expensive workover. In addition, the sand flowing from the subsurface formation may leave therein a cavity which may result in caving of the formation and collapse of the casing.
In order to limit sand production, various techniques have been employed for preventing formation sands from entering the production stream. One such technique, commonly termed "gravel packing", involves the forming of a gravel pack in the well adjacent the entire portion of the formation exposed to the well to form a gravel filter. In a cased perforated well, the gravel may be placed inside the casing adjacent the perforations to form an inside-the-casing gravel pack or may be placed outside the casing and adjacent the formation or may be placed both inside and outside the casing. Various such conventional gravel packing techniques are described in U.S. Pat. Nos. 3,434,540; 3,708,013; 3,756,318; and 3,983,941. Such conventional gravel packing techniques have generally been successful in controlling the flow of sand from the formation into the well.
In U.S. Pat. No. 4,378,845, there is disclosed a special hydraulic fracturing technique which incorporates the gravel packing sand into the fracturing fluid. Normal hydraulic fracturing techniques include injecting a fracturing fluid ("frac fluid") under pressure into the surrounding formation, permitting the well to remain shut in long enough to allow decomposition or "break-back" of the cross-linked gel of the fracturing fluid, and removing the fracturing fluid to thereby stimulate production from the well. Such a fracturing method is effective at placing well sorted sand in vertically oriented fractures. The preferred sand for use in the fracturing fluid is the same sand which would have been selected, as described above, for constructing a gravel pack in the subject pay zone in accordance with prior art techniques. Normally, 20-40 mesh sand will be used; however, depending upon the nature of the particular formation to be subjected to the present treatment, 40-60 or 10-20 mesh sand may be used in the fracturing fluid.
The fracturing sand will be deposited around the outer surface of the borehole casing so that it covers and overlaps each borehole casing perforation. More particularly, at the fracture-borehole casing interface, the sand fill will cover and exceed the width of the casing perforations,and cover and exceed the vertical height of each perforation set. Care is also exercised to ensure that the fracturing sand deposited as the sand fill within the vertical fracture does not wash out during the flow-back and production steps. After completion of the fracturing treatment, fracture closure due to compressive earth stresses holds the fracturing sand in place.
In most reservoirs, a fracturing treatment employing 40-60 mesh gravel pack sand, as in U.S. Pat. No. 4,378,845, will prevent the migration of formation sands into the wellbore. However, in unconsolidated or loosely consolidated formations, such as a low resistivity oil or gas reservoir, clay particles or fines are also present and are attached to the formation sand grains. These clay particles or fines, sometimes called reservoir sands as distinguished from the larger diameter or coarser formation sands, are generally less than 0.1 millimeter in diameter and can comprise as much as 50% or more of the total reservoir components. Such a significant amount of clay particles or fines, being significantly smaller than the gravel packing sand, can migrate into and plug up the gravel packing sand, thereby inhibiting oil or gas production from the reservoir.
A hydraulic fracturing method employing a special sand control technique was disclosed in U.S. Pat. No. 4,549,608. The fracturing fluid utilized contained an agent for stabilizing clay particles or fines along a fracture face. A proppant comprised of gravel packing sand was injected into the fracture. The sand utilized was not suitable for use in certain acid and high temperature environments encountered in some formations.
Therefore, what is needed is a novel sand control method for use in producing an unconsolidated or loosely consolidated oil or gas reservoir which comprises a hydraulic fracturing method that stabilizes the clay particles or fines along the fracture face and which also creates a very fine refractory gravel pack along the length of such fracture face.
SUMMARY OF THE INVENTION
A sand control method is provided for use in a borehole having an unconsolidated or loosely consolidated oil or gas reservoir which is otherwise likely to introduce substantial amounts of sand into the borehole. The borehole casing is perforated through the reservoir at preselected intervals. The reservoir is hydraulically fractured by injecting a fracturing fluid through the casing perforations containing a clay stabilizing agent for stabilizing the clay particles or fines along the resulting formation fracture for the entire length of the fracture face so that they adhere to the formation sand grains and don't migrate into the fracture during oil or gas production from the reservoir. A proppant containing a fine mesh refractory gravel pack material is injected into the formed fracture. Hydrocarbonaceous fluids are then produced from the reservoir through said fracture.
The fracturing fluid is injected at a volume and rate to allow the stabilizing agent to penetrate the fracture face to a depth sufficient to overcome the effects of fluid velocity increases in oil or gas production flow or the movement of clay particles or fines located near the fracture face into the fracture as such production flow linearly approaches the fracture face.
Another finer mesh refractory material may also be included in the fracturing fluid. During hydraulic fracturing, the finer mesh refractory material is pushed up against the fracture face to produce a very fine mesh refractory gravel filter for preventing the migration of clay particles or fines from the reservoir into the fracture, which can plug said gravel pack material, which is thereafter injected into the fracture. Preferably, the finer mesh refractory material is about 100 mesh while the gravel packing refractory material is about 40-60 mesh.
In another aspect, a refractory gravel pack may be added inside the casing prior to production to assure the extension of gravel packing material into the fracture since the fracture step has brought the fracture right up to the casing perforations.
It is therefore an object of this invention to provide a novel proppant to be used in a fracture to allow for increased heat transfer into a formation when a thermal oil recovery operation is utilized.
It is a further object of this invention to provide for a novel proppant which is stable in the formation when high temperatures are generated from a formation via a thermal oil recovery method.
It is yet a further object of this invention to provide for a novel proppant which will prolong the life and effectiveness of a created fracture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of a foreshortened, perforated well casing at a location within an unconsolidated or loosely consolidated formation, illustrating vertical perforations, vertical fractures, and fracturing sands which have been injected into the formation to create the vertical fractures in accordance with the method of the present invention.
FIG. 2 is a cross-sectional end view of the reservoir fracture of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, a foreshortened borehole casing, designated generally as 10, is illustrated which is disposed within a loosely consolidated or unconsolidated formation 15. The borehole casing 10 may be a conventional perforatable borehole casing, such as, for example, a cement sheathed, metal-lined borehole casing.
The next step in the performance of the preferred embodiment method is the perforating of casing 10 to provide a plurality of perforations at preselected intervals therealong. Such perforations should, at each level, comprise two sets of perforations which are simultaneously formed on opposite sides of the borehole casing. These perforations should have diameters between 1/4 and 3/4 of an inch, be placed in line, and be substantially parallel to t he longitudinal axis of the borehole casing.
In order to produce the desired in-line perforation, a conventional perforation gun should be properly loaded and fired simultaneously to produce all of the perforations within the formation zone to be fractured. Proper alignment of the perforations should be achieved by equally spacing an appropriate number of charges on opposite sides of a single gun. The length of the gun should be equal to the thickness of the interval to be perforated. Azimuthal orientation of the charges at firing is not critical, since the initial fracture produced through the present method will leave the wellbore in the plane of the perforations. If this orientation is different from the preferred one, the fracture can be expected to bend smoothly into the preferred orientation within a few feet from the wellbore. This bending around of the fracture should not interfere with the characteristics of the completed well.
Following casing perforation, the formation is fractured in accordance with the method of the present invention to control sand production during oil or gas production. When fracturing with the method taught in U.S. Pat. No. 4,378,845, oil or gas production inflow will be linear into the fracture as opposed to radial into the well casing. This patent is incorporated by reference. From a fluid flow standpoint, there is a certain production fluid velocity required to carry fines toward the fracture face. Those fines located a few feet away from the fracture face will be left undisturbed during production since the fluid velocity at the distance from the fracture face is not sufficient to move the fines. However, fluid velocity increases as it linearly approaches the fracture and eventually is sufficient to move fines located near the fracture face into the fracture. It is, therefore, a specific feature of the present invention to stabilize such fines near the fracture faces to make sure they adhere to the formation sand grains and don't move into the fracture as fluid velocity increases. Prior stabilization producers have only been concerned with radial production flow into the well casing which would plug the perforations in the casing. Consequently, stabilization was only needed within a few feet around the well casing. In an unconsolidated sand formation, such fines can be 30%-50% or more of the total formation constituency, which can pose quite a sand control problem. Stabilization is, therefore, needed at a sufficient distance from the fracture face along the entire fracture line so that as the fluid velocity increases toward the fracture there won't be a sand control problem.
A brief description of the fracturing treatment of the invention will now be set forth. Initially, a fracture fluid containing an organic clay stabilizing agent is injected through the well casing perforations 10 into the formation 11, as shown in FIG. 1. Such a stabilizing agent adheres the clay particles or fines to the coarser sand grains. In the same fracturing fluid injection, or in a second injection step, a very small mesh fused refractory material, such as 100 mesh, is injected. As fracturing continues, the small mesh fused refractory material, will be pushed up against the fractured formation's face 16 to form a layer 12. Thereafter, a proppant injection step fills the fracture with a larger mesh fused refractory material, preferably 40-60 mesh to form a layer 13. A cross-sectional end view of the reservoir fracture is shown in FIG. 2. It has been conventional practice to use such a 40-60 mesh sand for gravel packing. However, for low resistivity unconsolidated or loosely consolidated sands, a conventional 40-60 mesh gravel pack will not hold out the fines. The combination of a 100 mesh fused refractory material layer up against the fracture face and the 4014 60 proppant fused refractory material layer makes a very fine grain gravel filter that will hold out such fines.
As oil or gas production is carried out from the reservoir, the 100 mesh fused refractory material layer will be held against the formation face by the 40-60 mesh proppant layer and won't be displaced, thereby providing for such a very fine grain gravel filter at the formation face. Fluid injection with the 40-60 mesh proppant fills the fracture and a point of screen out is reached at which the proppant comes all the way up to and fills the perforations in the well casing. The fracturing treatment of the invention is now completed and oil or gas production may now be carried out with improved sand control. Prior to production, however, it might be further advantageous for sand control purposes to carry out a conventional inside the casing gravel pack step. Such a conventional gravel pack step is assured of extending the packing material right into the fracture because the fracturing step has brought the fracture right up to the well casing perforations. A propping agent or fused refractory gravel concentration of about one pound per gallon to about fifteen pounds per gallon can be used. A more detailed description of a field operation wherein sand is employed as proppant is disclosed in U.S. Pat. No. 4,549,608 which issued on Oct. 29, 1985. This patent is hereby incorporated by reference herein.
Following the fracturing treatment, a conventional gravel pack was placed in and immediately surrounding the well casing to hold the 40-60 mesh sand in place and the well was opened to oil or gas flow from the reservoir.
The desired fused refractory material to be utilized herein comprises silicon carbide or silicon nitride. As is preferred, the size of the fused refractory material utilized should be from about 20 to about 100 U.S. Sieve. This fused refractory material should have a Mohs hardness of about 9. Both silicon carbide and silicon nitride have excellent thermal conductivity. Silicon nitride, for example, has a thermal conductivity of about 10.83 BTU/in/sq. ft/hr./°F. at 400° to 2400° F. A suitable silicon carbide material is sold under the trademark Crystolon and can be purchased from Norton Company, Metals Division, Newton, Mass. A suitable silicon nitride material can also be purchased from Norton Company.
This novel proppant is particularly advantageous when a thermal process is utilized during the recovery of hydrocarbonaceous fluids from a formation. One thermal recovery process which can be utilized comprises a steam-flood. A thermal oil recovery process wherein steam is utilized to remove viscous oil from a formation which can be employed herein is described in U.S. Pat. No. 4,598,770. This patent issued to Shu et al. on July 8, 1986 and is hereby incorporated by reference. Another thermal oil recovery method wherein steam is utilized which can be employed herein is described in U.S. Pat. No. 4,593,759. It issued to Penick on June 10, 1986 and is hereby incorporated by reference. Walton describes yet another thermal oil recovery process which can be used to recover hydrocarbonaceous fluids in U.S. Pat. 3,205,944. This patent issued on Sept. 14, 1965 and is hereby incorporated by reference. By this method hydrocarbons within the formation are auto-oxidized. Auto-oxidation occurs at a relatively low rate and the exothermic heat of reaction heats up the formation by a slow release of heat. Since during auto-oxidation, the temperature within the formation can be the ignition temperature of the hydrocarbon material within said formation, the auto-oxidation reaction is controlled to prevent combustion of the hydrocarbon material within the formation.
Heat generated by either of these methods is more effectively transferred into the formation via the fused refractory material used as a proppant herein. Since the fused refractory material used as a proppant herein allows for a more efficient transfer of heat into the formation, smaller volumes of steam can be utilized, for example, in a steam-flood process. Similarly, when using the auto-oxidation method to heat a formation, decreased amounts of oxygen can be used to obtain the same degree of heating within the formation. Once the formation has been heated to the desired degree, increased volumes of hydrocarbonaceous fluids can more effectively be produced to the surface from the formation.
In addition to providing high thermal conductivity, the proppant and fine refractory material used herein can also withstand acids used in treating a well and/or formation, including HCl/HF acid mixtures. The proppant and fine refractory material also provide for high fracture conductivity, acid stability, and high temperature stability when use in formations containing these environments. As will be understood by those skilled in the art, HCl/HF acid mixtures are often used when clearing channels in the formation and hear the well to increase the production of hydrocarbonaceous fluids after sand and clay materials have reduced flow through said channels.
The proppant material used herein could also be manufactured in a desired shape to cause it to bridge and remain in place within a created fracture. Using a shape required for a particular fracture would permit the proppant to more effectively prop the formation. It would also allow the proppant to withstand greater formation pressures while in a fracture.
Obviously, many other variations and modifications of this invention as previously set forth may be made without departing from the spirit and scope of this invention as those skilled in the art readily understand. Such variations and modifications are considered part of this invention and within the purview and scope of the appended claims.
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A process for hydraulic fracturing where a fracturing fluid contains a clay stabilizing agent. Said agent stabilizes clay particles or fines along the face of a resulting formation fracture. Thereafter a fused refractory proppant is injected into the fracture. The proppant increases thermal conductivity during a steam-flooding oil recovery method while controlling clay particles and sand.
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BACKGROUND
Ram-type blowout preventers are used to close the upper end of a well bore to maintain the well under control whenever there is danger of a blowout. The rams move in guideways in the body of the blowout preventer and when closed are positioned to seal across the bore through the body with a ram front packer. To make the seal complete a sealing element is provided between the ram and the ram guideways, usually across the top and side of the ram extending from the ram front packer. The operation of the rams causes wear particularly in the lower surface of the guideway, and excessive wear can reposition the ram so that a leak can occur across the ram top sealing element.
U.S. Pat. No. 3,692,316 discloses a ram-type blowout preventer with keys secured to the underside of the rams sliding in slots in the bottom of the guideways to maintain the rams in proper alignment but there is no suggestion of compensating for wear.
U.S. Pat. No. 1,970,964 discloses a well flow stopper which includes a plate that is moved across the bore and includes an upper packer and a pair of lower springs to support the plate and urge it upward with the aid of pressure to sealed position. U.S. Pat. No. 1,981,279 discloses a ram type blowout preventer including a spring-pressed ring to hold the rams against the upper seat. The use of springs as shown in these two patents would not be effective to compensate for excessive wear in guideways and/or ram lower surface, particularly when the string passing therethrough is hung in tension on the ram.
SUMMARY
The present invention relates to a ram-type blowout preventer having a body with a central bore and guideways extending outwardly therefrom with rams movable therein and with means to compensate for wear in the ram guideways or in the ram to ensure that the ram seals are held against the upper interior surface of the guideways.
An object of the present invention is to provide an improved ram-type blowout preventer which ensures the ram top and side seals are effective independent of wear of the rams and guideways.
Another object of this invention is to provide an improved ram type blowout preventer which does not require shop repair with welding and subsequent machining to correct and compensate for excessive ram and/or guideway wear.
Still another object of this invention is to provide an improved ram type blowout preventer which can be quickly repaired to compensate for excessive wear of the ram guideways and the rams.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages are hereinafter set forth and explained with reference to the drawings wherein:
FIG. 1 is an elevation view (partly in section) of the improved blowout preventer of the present invention.
FIG. 2 is a partial sectional and elevation view of a portion of the improved blowout preventer of the present invention.
FIG. 3 is an end elevation view of one form of improved ram of the present invention.
FIG. 4 is a sectional view taken along line 4--4 in FIG. 3.
FIG. 5 is a view of the front of another form of improved ram of the present invention.
FIG. 6 is a view of the rear of a modified form of improved ram of the present invention.
FIG. 7 is a bottom view of the ram shown in FIG. 6.
FIG. 8 is a bottom view of the insert skid used on the ram shown in FIGS. 6 and 7.
FIG. 9 is a sectional view of the insert skid taken along line 9--9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, blowout preventer 10 is shown having body 12 through which central bore 14 extends with opposed aligned guideways 16 extending outward from bore 14. Ram 18 is moved in guideway 16 by suitable actuator 20 connected to ram 18 by connector rod 22. Ram 18 includes the usual ram front packer 24 and sealing element 26 which extends along the sides and across the top of ram 18 and seals against the interior of guideway 16.
The ram 18 shown in FIGS. 3 and 4 has the front packer slot 25 and a lower mud slot 28. Skids 30 and shims 32 are mounted in mud slot 28 by cap screws 34 which extend through end flanges 36 and shims 32. With different thicknesses of shims 32 or the use of multiple shims 32 compensation is provided for the wear of the lower surface of guideways 16 or the surface of skids 30 to ensure that sealing elements 26 are maintained in sealing engagement with the upper interior of guideways 16.
Another form of the improved blowout preventer ram of the present invention is shown in FIG. 5 as ram 38 which has the usual mud slot 40 extending from front to rear on its lower side but formed by skids 42 secured to its lower side. Skids 42 are shaped to conform to the shape of the guieways in which they are to be used and are secured to ram 38 by suitable fastening means, such as cap screws 44, with at least two or more being used to secure each of skids 42. As with the previously described form, shims 46 are positioned between skids 42 and the lower side of ram 38. With different thicknesses of shims 46 or with the use of multiple shims 46, skids 42 can be adjusted to compensate for wear of the guideways or of skid surfaces 43, and to ensure that its top and side sealing element are properly positioned for sealing.
Another form of the present invention is shown in FIGS. 6 and 7 as ram 50. Ram 50 has an exterior shape to fit closely in the guideway in which it is to be installed. Slot 52 across the rear of ram 50 is provided for the attachment of the connecting rod (not shown). Recess 54 on the front face of ram 50 is provided to receive tubular members therein.
Mud slot 56 on the lower surface of ram 50 includes rear recess 58 and forward slot 60 which is narrower than recess 58 as shown in FIG. 7. Skid 62 is positioned in recess 58 and extends into slot 60. Skid 62 includes body 64 with Y-shaped slot 66 extending therethrough as shown with the double slots 68 opening on the rear. Skid 62 is secured to ram 50 by screws 70 which are positioned in recesses 72. The heads of screws 70 are positioned wholly within recesses 72 so that they never engage the guideway in which ram 50 is positioned. To adjust for wear one or more shims 74 is positioned in slot 56. Skid 62 provides a pair of side skid surfaces 76 and triangular skid surface 78.
It is suggested that screws 34, 44 and 70 be made of a high strength non-galling material such as the thermoplastic polyester sold by E. I. du Pont de Nemours under the trademark "RYNITE" or the nylon sold by the same company under the trademark "ZYTEL", to avoid scarring of guideways 16 in the event a screw works loose. An alternate structure for preventing galling damage from a loose fastener would be to cap the head of the fastener with a non-galling material, such as a polytetrafluoroethylene so that if it becomes loose the head will readily slide with the movement of the ram and will not scar the guideway.
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A ram-type blowout preventer including a body with a central bore and guideways extending outward therefrom, a ram in each guideway with means for moving it inward and outward and means for compensating for wear of the guideway or ram including at least one skid secured to the lower surface of the ram.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of the earlier filing date of, and contains subject matter related to that disclosed in U.S. Provisional Application Ser. No. 60/328,107, filed Oct. 11, 2001, the entire contents of which is incorporated herein by reference.
COPYRIGHT NOTIFICATION
[0002] Portions of this patent application contain materials that are subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document, or the patent disclosure, as it appears in the Patent and Trademark Office, but otherwise reserves all copyright rights.
COMPUTER PROGRAM LISTING APPENDIX
[0003] A computer program listing appendix is included with this application and the entire contents of the computer program listing appendix is incorporated herein by reference. The computer program listing appendix is stored on two sets of identical compact discs, each set of discs comprising one compact disc, containing the files identified in Appendix 1. The computer program listing and the files contained on the compact discs are subject to copyright protection and any use thereof, other than as part of the reproduction of the patent document or the patent disclosure, is strictly prohibited.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates, generally, to systems and methods for processing and reporting information and data, such as business information, and more particularly, to systems, software, hardware, products, and processes for use by businesses, individuals and other organizations to collect, process, distribute, analyze and visualize information, including, but not limited to, business intelligence, data visualization, data warehousing, and data mining.
[0006] 2. Discussion of the Background
[0007] Business analytics is focused on deriving actionable intelligence from transactional or other process automation systems, content distribution systems, and databases. The proliferation in the use of such transactional and other process automation and content delivery systems has created a substantial need for efficient and effective analytical systems. The Internet has emerged as a global medium that allows millions of users to more efficiently obtain information, communicate, and conduct business. As Internet usage has grown, companies have increasingly come to rely on Web-based systems, Internet and intranet sites as important business channels.
[0008] Through the Internet, a company can establish and maintain large numbers of direct relationships and reduce costs in traditional infrastructures such as retail outlets, distribution networks, and sales personnel. Both traditional and Web-based companies use the Internet to communicate marketing and other important information to customers, and manage relationships with vendors, partners, and employees. Increasingly, companies are using the Internet to generate revenue through the sale of goods and services, as well as through the sale of advertising.
[0009] However, managing, evaluating, monitoring and optimizing online transactions, and providing for personalized customer relationships are highly complex processes. In part, as a consequence of the Internet technology gap between what works in theory and what works in practice, a crisis in web usability exists as evidenced by numerous research studies:
[0010] Forrester research revealed that:
[0011] 50% of potential online sales are lost when online users cannot find what they are looking for;
[0012] 40% of online users do not return to a site when their first visit resulted in a negative experience; and
[0013] 75% of all shopping carts are abandoned.
[0014] Research by Jakob Nielsen shows that:
[0015] Worldwide, the cost of poor intranet usability will grow to about $100 billion by the year 2001; and
[0016] 90% of commercial Web sites have poor usability.
[0017] This research data provides an objective view on the seriousness of the usability crisis. It is becoming increasingly clear to companies that their web-based systems are not as effective as they need to be, and that current analytical tools are not delivering the information required to address these problems.
[0018] Companies pay millions of dollars to operate their e-business web sites, yet have little or no direct visibility into their operations. Reporting systems for Enterprise Resource Planning (ERP) applications are woefully inadequate in giving business managers cogent information in time to make changes. Companies buy millions of dollars of software and services for business systems that they cannot monitor or optimize at a business level, and information is either not delivered to executives or it is delivered in a form that lacks continuity, interactivity, timeliness and transparency. For all of the dollars that have been spent on automating business systems, no one has been able to provide to the person who is paying for the systems an ability to interactively visualize or analyze the operations of the system and optimize return on their investment. These and other deficiencies divert millions, if not billions, of dollars from the bottom lines of companies worldwide.
[0019] Millions of web sites have been developed by businesses, however many of them are ineffective or sub-effective, and some are even damaging to their enterprises. Managers and executives have little visibility into the ongoing operations of their sites, regardless of their purpose. In many cases, millions of dollars have been spent to build these sites, many of which are intended to support business critical, if not mission critical, business processes, such as sales and distribution. Yet executives and managers do not have the tools to stay on top of their operations, let alone optimize them. In the best of cases, managers get reports once a week or once a month that give them a snapshot of their site's performance. Put plainly, the people with checkbooks, decision-making authority, financial experience and authority are locked out of the site optimization process, and are expected to act blindly with poor information, through other people.
[0020] With the advent of the Internet, companies, their customers, vendors, partners, distribution channels, and employees now have the means to more efficiently share information, automate business processes, and conduct business on a global scale. With the user/customer's ability to change providers at the click of a button, companies must find ways to differentiate their offerings and personalize their business transactions to meet customer needs. Additionally, companies must ensure that the user experience is satisfying and that their sites' design does not inhibit the user's desired outcome (purchasing, enrolling, retrieving information, etc.) or loyalty ratios will suffer, driving up customer acquisition costs. The bar for doing it right is rising each day.
[0021] With almost all web-based applications, business managers do not have the ability to react to market conditions with real-time control. Tools that provide managers with accessible and useful insights into their Internet/intranet processes are desperately needed. Real dollars are being spent, and the investments that they are supporting need to be managed and monitored with tools that make the automated systems and sites “real” to managers.
[0022] Business systems in general have suffered through lack of reporting facilities that are accessible, usable, and understandable to key managers and executives. This lack of visibility costs companies worldwide an incalculable amount of wasted expenditure and lost opportunity.
[0023] Human beings have an incredible facility for visual pattern recognition that far transcends their ability to glean the same patterns from data formatted in textual reports. When they are visually enabled, they can explore vast amounts of data, rapidly to identify patterns and opportunities that were previously unnoticed. Typical reports and periodic updates that pervade conventional decision support and executive information systems, however, are tabular, static and difficult to interpret.
[0024] More recently, On-Line Analytical Processing (OLAP) has become available as a tool for providing c-business analytics. OLAP is a category of software technology that enables analysts, managers and executives to gain insight into data through fast, consistent, interactive access to a wide variety of possible views of information that has been transformed from raw data to reflect the real dimensionality of the enterprise as understood by the user. OLAP functionality is characterized by dynamic multi-dimensional analysis of consolidated enterprise data supporting end user analytical and navigational activities including: calculations and modeling applied across dimensions, through hierarchies and/or across members; trend analysis over sequential time periods; slicing subsets for on-screen viewing; drill-down to deeper levels of consolidation; reach-through to underlying detail data; rotation to new dimensional comparisons in the viewing area. OLAP is typically implemented in a multi-user client/server mode and offers consistently rapid response to queries, regardless of database size and complexity. OLAP helps the user synthesize enterprise information through comparative, personalized viewing, as well as through analysis of historical and projected data in various “what-if” data model scenarios. Typically, OLAP is facilitated by an OLAP Server that processes the data for a client application that presents data and helps users define queries.
[0025] As noted above, OLAP enables a user to easily and selectively extract and view data from different points-of-view. For example, a user can request that data be analyzed to: (i) display a spreadsheet showing all of a company's beach ball products sold in Florida in the month of July; (ii) compare revenue figures with those for the same products in September; and then (iii) see a comparison of other product sales in Florida in the same time period. To facilitate this kind of analysis, OLAP data is typically stored in a multidimensional database. Whereas a relational database can be thought of as two-dimensional, a multidimensional database considers each data attribute (such as product, geographic sales region, and time period) as a separate “dimension.” OLAP software can locate the intersection of dimensions (all products sold in the Eastern region above a certain price during a certain time period) and display them. Attributes such as time periods can be broken down into sub-attributes.
[0026] Notwithstanding the enhanced querying, calculation, and indexing functionality of OLAP systems, and their multidimensional access to data, such systems still lack the capability to efficiently and effectively measure, manage, evaluate, monitor, and optimize current transactional, process automation, content distribution, web-based type business systems. Presently available OLAP systems are incapable of providing the required business intelligence information in a form that is effectively usable and meaningful, and in a time frame that enables effective utilization of the information. Moreover, such systems do not have the capability to interactively visualize or analyze the business information and data collected, and to process, distribute, analyze, and visualize such business information in real-time.
[0027] Consequently, there is a need for a business analytics system that is capable of interactive visualization and analysis of business information and data, that can collect, process, distribute, analyze, and visualize such business information and data in real-time. There is a need for such a system that is capable of providing reports that are visual, interactive, and easy to understand, thereby taking advantage of human beings' natural ability for visual pattern recognition. There is a need for providing actionable intelligence from transactional or other process automation systems, content distribution systems and databases. More specifically, there is a need to allow users to visually explore vast amounts of data in real-time by pointing and clicking to make queries, and to select data in, and present it through, multi-dimensional graphical representations. In addition, there is a need to provide actionable intelligence to a user to allow the user to 1) evaluate the usability of the site; 2) assess modifications to the site; 3) improve conversion rates; 4) improve site performance; 5) improve customer satisfaction; 6) optimize marketing campaigns; 7) reduce customer session loss; and 8) forecast the potential return on a campaign or site change and prioritize investments.
SUMMARY OF THE INVENTION
[0028] The primary object of the present invention is to overcome the deficiencies of the prior art described above by providing a system, method, and computer program product for processing and visualizing information, which is capable of interactive visualization and analysis of information and data, that can collect, process, distribute, analyze, and visualize such information and data, such as business information, in real-time.
[0029] Another key object of the present invention is to provide a system, method, and computer program product for processing and visualization of information, which can provide actionable intelligence from transactional or other process automation systems, content distribution systems, and databases, thereby optimizing the usability and performance of such systems, including Internet and intranet applications, and providing enhanced utility to end-users and more profits for businesses.
[0030] Another key object of the present invention is to provide a system, method, and computer program product that can assist in the analysis and optimization of e-business processes, such as marketing, sales, content delivery, customer service, purchasing and others.
[0031] Yet another key object of the present invention is to provide a system, method, and computer program product enabling the measurement, monitoring, exploration, evaluation, and optimization of critical business systems, assets, and investments
[0032] A key object of the present invention is to provide a system, method, and computer program product that allows users' to monitor, analyze, control and optimize their investments in customer relationships, marketing campaigns, operational systems, and automated business processes.
[0033] Another key object of the present invention is to provide a system, method, and computer program that facilitates improved process conversion rates including: retail sales transactions, content distribution, purchasing, shopping, customer service, registration, application, status checking, research, and others.
[0034] Yet another key object of the present invention is to provide a system, method, and computer program product that can take advantage of scientific processes, such as enabling controlled experimentation with users' interactive systems and marketing campaigns.
[0035] Another key object of the present invention is to provide a system, method, and computer program product that provides visibility into automated business processes, historically and in real-time.
[0036] Yet another object of the present invention is to provide a system, method, and computer program product that provides accountability by tracking objectives verses actual results on an ongoing basis.
[0037] Another object of the present invention is to provide a system, method, and computer program that provides enhanced customer and market knowledge and insight, thereby enabling higher average sales per customer, reduced customer session loss, and the ability to personalize customer interaction based on facts, not guesswork.
[0038] Yet another object of the present invention is to provide a system, method, and computer program product that enables the optimization of site and marketing campaign results, and increased yield from marketing and advertising campaign spending.
[0039] Another object of the present invention is to provide a system, method, and computer program product that facilitates increased enrollment, registration and data collection rates.
[0040] Yet another object of the present invention is to provide a system, method, and computer program product that enables improved site performance (improved navigation, reduced load, increased loading speed, etc.), resulting in lower infrastructure expenses.
[0041] Another object of the present invention is to provide a system, method, and computer program product that provides for processing and visualization of business information, thereby facilitating improved customer satisfaction, resulting in increased site loyalty, greater visitation frequency, larger percentage of repeat visitors, reduced customer acquisition costs, and longer user sessions.
[0042] Yet another object of the present invention is to provide a system, method, and computer program product that provides an ability to forecast the potential return on a campaign or site change, and to prioritize investments.
[0043] Another object of the present invention is to provide a system, method, and computer program product that provides reduced customer support expenses and reduced off-line sales and support expenses.
[0044] Still another object of the present invention is to provide a system, method, and computer program product that more efficiently utilizes customer information to provide actionable intelligence to the user.
[0045] Another object of the present invention is to provide a system, method, and computer program product that reduces the amount of data that needs to be transmitted to the client application.
[0046] Yet another object of the present invention is to provide a system, method, and computer program product that performs statistical sampling in order to permit processing of a large amount of data in an extremely short period of time.
[0047] Still another object of the present invention is to provide a system, method, and computer program product that is fault-tolerant, highly scalable, extensible, and flexible.
[0048] Another object of the present invention is to provide a system, method, and computer program product that provides more comprehensive, higher quality information to business people so that they can make better business decisions faster and more effectively, while requiring less manual effort and company expense.
[0049] Still another object of the present invention is to provide a system, method, and computer program product that provides highly graphical, point-and-click interactive access to vast amounts of data, at very high access speeds, providing the needed information in a way that can be quickly and visually understood.
[0050] Yet another object of the present invention is to provide a system, method, and computer program product that permits users, in real-time, to actively analyze vast amounts of business information in task oriented workspaces, or to passively monitor performance through dashboard views alone or in collaboration with their teams.
[0051] The present invention achieves these objects and others by providing a system, method, and computer program product for processing and visualization of information comprising a Visual On-Line Analytical Processing (VOLAP) Platform comprising one or more Visual Workstations, a Visual Server, and one or more Visual Sensors.
[0052] The Visual Sensor is a processing module that communicates with, and may execute on the same computer system as, an automated processing system, such as a web server. The Visual Sensor collects information and data, such as information and data relating to customers, marketing campaigns, operational systems, and/or automated business processes from the automated processing system. The collected data is stored in a queue, referred to as the Visual Sensor queue, which communicates with the automated processing system.
[0053] The Visual Server retrieves the collected data from the Visual Sensor queue and processes that data, which may include statistical sampling, for use by the Visual Workstation. The Visual Server stores the information indefinitely and continually updates the Visual Workstations with the newly processed data.
[0054] The Visual Workstation executes client specific applications and provides an interface for performing administrative functions to the system. The Visual Workstation includes high-speed graphics capabilities for fast multi-dimensional graphic presentations of e-business analytics to the user. In addition, the Visual Workstation provides a user interface for manipulating data, performing queries, and otherwise interacting with the resident application. The Visual Workstation provides a complete application framework by supporting multiple types of visualization, the organization of visualizations into workspaces and dashboards, and the ability to collaborate with other users of Visual Workstation.
[0055] A client application module is the means by which data is processed for presentation to the user on the Visual Workstation. The client application interfaces with the VOLAP platform and, more specifically, the information and data processed by the VOLAP platform, through its implementation on the Visual Workstation. The client application may process sample data or unsampled data depending on the amount of information collected. The processed data is then presented to the user through the Visual Workstation.
[0056] The system, method, and computer program product of the present invention takes advantage of the user's inherent pattern recognition capacity, allowing his or her mind to quickly identify trends, changes, opportunities, correlations, and problems through the use of the advanced visualization techniques and real-time online analytical processing enabled by the present invention.
[0057] The present invention extends and modifies the typical definition of OLAP in the following ways, amongst others:
1. queries are executed in milliseconds, rather than in seconds, minutes or hours; 2. enables metrics and dimensions to be constantly updated on the user's visual desktop as the fact data changes, in real-time, due to ongoing data collection; 3. does not create aggregations or “cubes” from fact data as a pre-processing step required before users are able to query the data. The present invention is capable of building multi-dimensional arrays and other data structures on the fly, from the fact data in the database, in milliseconds, for interactive drilling and slicing, as required; 4. permits users to define selections or queries through interacting with visualizations that depicts metrics and data dimensions; 5. does not require that the client application be connected to a back-end OLAP server for a user to use the application; and 6. provides a robust interactive, multi-dimensional visualization interface that is intuitive and easy for users to explore data.
[0064] Multi-dimensional graphical displays require more data to be accessed from data subsystems or databases than do the other reporting displays, and even today's best OLAP, decision support and business intelligence software products produce such reports in seconds or minutes. The present invention provides the data in milliseconds so that the user can enjoy a graphical display that is responsive and capable of interactively animating business intelligence information. In addition, this data can be interactively displayed in a myriad of visual manners that assist users in recognizing important business patterns, problems, opportunities and trends.
[0065] The present invention has the ability to take advantage of scientific processes, such as enabling controlled experimentation with users' interactive systems and marketing campaigns. Users' can form a hypothesis about how a marketing campaign and internet site may be changed, test market the hypothetical change on a subset of potential visitors and actual visitors, study the results, and either iterate further with another test, or roll the campaign out to a broader market to capture the benefits proven likely in the market test.
[0066] Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements.
[0068] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0069] FIG. 1 is a functional block diagram of the architecture for a system for processing and visualization of information according to the present invention.
[0070] FIG. 2 is a more detailed functional block diagram functional of the architecture for a system for processing and visualization of information according to the present invention.
[0071] FIG. 3 is a functional block diagram of the architecture for a system for processing and visualization of information of FIG. 1 showing examples of different configurations of the system.
[0072] FIG. 4 is a functional block diagram of the architecture for a system for processing and visualization of information of FIG. 1 showing an example of the system implemented with the Visual Site application.
[0073] FIG. 5 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Color Ramp Metrics workspace.
[0074] FIG. 6 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Customer Retention Analysis workspace.
[0075] FIG. 7 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing an Individual Mapped Sessions workspace.
[0076] FIG. 8 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing an Intraday Analysis workspace.
[0077] FIG. 9 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Metrics and Timeline workspace.
[0078] FIG. 10 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Process Analysis workspace.
[0079] FIG. 11 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Referrer all Metrics workspace.
[0080] FIG. 12 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Referrer Analysis workspace.
[0081] FIG. 13 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Registered Customer Geography workspace.
[0082] FIG. 14 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows a Retention and Duration Timing workspace.
[0083] FIG. 15 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Return What-if More Visitors to Pages workspace.
[0084] FIG. 16 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Return What-if Visitor Metrics workspace.
[0085] FIG. 17 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Returning Customer Analysis workspace.
[0086] FIG. 18 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Returning Customer Value Segmentation workspace.
[0087] FIG. 19 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Site Traffic Conversion and Value Analysis workspace.
[0088] FIG. 20 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Status and Metric Legend.
[0089] FIG. 21 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Visit Timing Return What-if workspace.
[0090] FIG. 22 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Visitor Session Duration Analysis workspace.
[0091] FIG. 23 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows a Visitor Session Detail workspace.
[0092] FIG. 24 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a Visits Conversion and Value workspace.
[0093] FIG. 25 is an illustrative workspace window generated by the system for processing and visualization of information of the present invention including multiple visualization windows showing a What-if More Visitors from Referrer workspace.
[0094] FIG. 26 is a flow diagram representing the process and/or data flow through the system for processing and visualization of information according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0095] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular networks, communication systems, computers, terminals, devices, components, techniques, data and network protocols, sampling techniques, communication protocols, storage techniques, software products and systems, enterprise applications, operating systems, enterprise technologies, middleware, development interfaces, hardware, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. Detailed descriptions of well-known networks, communication systems, computers, terminals, devices, components, techniques, data and network protocols, sampling techniques, communication protocols, storage techniques, software products and systems, enterprise applications, operating systems, enterprise technologies, middleware, development interfaces, and hardware are omitted so as not to obscure the description of the present invention.
I. General Design Concepts
[0096] A. Conversion
[0097] Many sites have been built and made accessible on the Internet and through intranets to allow customers or end-users to interact with companies. At a high-level, a business process is any set of pages in a site with a first and a last page, where if users complete the process, they have established some type of value for the company, such as making a purchase, registering for a promotion, applying for a loan, etc. Customer self-service decreases the costs of alternative business processes, such as call center processing, and drives revenue through sales, referrals, advertising and other mechanisms. The tasks that the customers or end-users can complete at a site vary dramatically by the type of business implementing the site and its processes, as illustrated by the following two examples.
[0098] A retail bank implements customer self-service business processes for, amongst other purposes: reviewing financial product offers, taking consumer applications for accounts, allowing the consumer to access credit card account information, mortgage applications, comparing rates and terms, etc.
[0099] An e-commerce site implements customer self-service business processes that allow consumers or business representatives to shop for products, configure orders, enter orders, check order statuses, register, login, get customer support, make payments, participate in promotions, etc.
[0100] In each case the customer begins a process when they have made clear that they wish to complete a given task by selecting a specific URL served by the site. The completion of that task, such as completing a payment, or registering as a new customer, is a “value event” for the site owner and the fulfillment of the site owner's objective in building the business process and presenting it to customers. There may be many steps, pages and forms presented to the customer in an Internet business process before the process is complete and the site receives value. Alternately, completion of process may require accessing only a single page. A “process conversion rate” is the rate at which a certain customer or type of customer completes a business process that produces a value event after they have expressed an initial interest in completing the business process or task. The higher the process conversion rates get, the more profitable the process will be, and the higher the return on the company's investment in building it and operating will get. The present invention assists in improving process conversion rates.
[0101] B. Metric
[0102] A metric is a numerical value set representing and relating a measurement or a derived and calculated measurement. For instance, the present invention can monitor the following metrics amongst others:
1. Visits—These are the measurements and calculations derived from the web server's data about when a user comes to the site, how long they stay and when they leave; 2. Value Events—This is a calculated metric that is derived from visits and simple user input that delineates when a visitor has done something that created value for the site; 3. Conversion—This is a calculated metric that depicts a measurement of the rate at which visits result in value events; 4. Return—This is a calculated metric that depicts the financial return of a particular value event; 5. Other Metrics—There are numerous other metrics that are both directly based on external measurements and in other cases calculated based on those metrics and user input through the client application; 6. Custom Metrics—Users of the present invention can create certain types of custom metrics to depict important information particular to their business; and 7. Temporary Metrics—Additionally, temporary metrics are created and play a part of certain types of analysis tasks.
[0110] C. Data Dimension
[0111] A dimension is a structural attribute of a data analysis system that is a list of members, all of which are of a similar type in the user's perception of the data. For example, all months, quarters, years, etc., make up a time dimension; likewise all cities, regions, countries, etc., make up a geography dimension. A dimension acts as an index for identifying values within a dimensional array. If one member of the dimension is selected, then the remaining dimensions in which a range of members (or all members) are selected defines a sub-dimension. If all but two dimensions have a single member selected, the remaining two dimensions define a spreadsheet (or a “slice” or a “page”). If all dimensions have a single member selected, then a single cell is defined. Dimensions offer a very concise, intuitive way of organizing and selecting data for retrieval, exploration and analysis. Some examples of data dimensions that are available in one example client application (Visual Site) and used to visualize metrics include, amongst others:
1. Clicks—These are the instances of visitors selecting URLs during their visits to view pages. 2. Referrers—This is the dimension of instances of referral of a visitor visiting. 3. Zip Code—This is the dimension of zip codes of visitors. 4. Page—This is the dimension of pages that that any visitors may have selected in their visits. 5. Custom Dimensions—Users may create certain types of custom data dimensions to depict important information particular to their business; and 6. Temporary Dimensions—In some cases temporary dimensions may be created as a part of a certain types of analysis tasks.
[0118] In addition, there are numerous other data dimensions that are either continuously managed by the VOLAP platform or are created in the process of data display and analysis.
[0119] D. Selection, Filter or Query
[0120] The terms selection, filter or query are generally used interchangeably. A selection, filter or query defines the search terms and conditions used by Visual Workstation to go to the database and retrieve data as defined by that selection, filter or query and present it to the user.
[0121] E. Visualization
[0122] A well-done visualization is a graphical representation of data that allows a person to more rapidly and completely understand patterns that exist in data as well as compare the relative magnitudes of data values versus their peers. There are many types of visualizations:
1. One-Dimensional Graphs and Histograms—One dimensional (1D) graphs depict a metric (e.g., a business metric) over one data dimension such as time. A histogram groups data values into buckets along that dimension such as, by week, or Mondays. 2. Two-Dimensional Graphs and Histograms—Two dimensional (2D) graphs depict one or two metrics over two data dimensions. For instance visitors to a site and their conversion rates to purchase as the metrics over the dimensions day of the week and hour of the day. 3. Multi-Dimensional Graphs and Histograms—Multi-dimensional (MD) graphs depict multiple metrics over multiple data dimensions. For instance visits, conversion rate, and benchmark visits over the dimensions hour of the day, day of the week, referrer, campaign, etc.
II. Structure and Architecture of System and Modules/Components
[0126] As shown in FIGS. 1-4 , the VOLAP Platform includes at least one Visual Sensor component 101 a - 101 c , a Visual Server 103 and at least one Visual Workstation 105 , 201 . Together they provide the underpinning technology platform required for VOLAP applications. The VOLAP Platform enables VOLAP applications that can be built to support different data domains, business needs and user requirements. The VOLAP application which is described as an example application herein is referred to as Visual Site, which is built for the owners and operators of Internet business sites. However, as will be evident to those skilled in the art, other applications for other automated processes may be designed to run on the VOLAP Platform as well. The software modules and components of the example embodiment of the present invention are written in C++, although any suitable language could be used.
[0127] The Visual Workstation is a desktop application that provides its users with a robust desktop operating environment that enables very fast multi-dimensional data analysis, robust data visualization, and an interactive method of defining queries of the fact data. Visual Workstation provides a complete application framework by supporting multiple types of visualization, the organization of visualizations into workspaces and dashboards, and the ability to collaborate with other users of Visual Workstation. Visual Workstation obtains data from the Visual Server and provides the operating environment for the application (e.g., Visual Site) and can be implemented on a desktop or notebook computer, or other suitable device.
[0128] The Visual Server is a real-time data integration and processing server that collects data from remote systems and databases, manages that data, transforms that data into a form that can be used by Visual Workstations, and manages the distribution of that data to Visual Workstations. The Visual Server can be configured to make requests of external systems to get data that can be integrated for analysis purposes. Visual Server is designed to require minimal maintenance and can be peered with other servers and data collection products to get data prepared for users of Visual Workstation. The Visual Server may operate on a stand-alone computer, or may share a computer with other applications.
[0129] The Visual Sensor is the measurement, collection and transmission software application. Visual Sensor is capable of interacting with its host (e.g., a web server) and is able to collect data, filter unnecessary data, queue the data for transmission, and ensure that the data is delivered to Visual Server. Visual Sensor may be customized for different systems. The Visual Sensors described in the example embodiments herein operate with Microsoft's Internet Information Server or Apache's Web Server. The Visual Sensor is resident on the web server computer in the embodiments described herein. As will be apparent to those skilled in the art, the Visual Sensor may be implemented on a computer other than the web server computer or computer on which the automated processing system is running, and may be adapted to operate with servers other than Microsoft's Internet Information Server and Apache's Web Server.
[0130] A VOLAP application is an application that uses the VOLAP Platform to provide certain business value to a certain type of company with certain needs. For instance, Visual Site, an example of a client application for the VOLAP platform, is built to provide business value to owners and operators of internet properties that automate certain business processes, marketing efforts and interact with the company's customers. The Visual Site application satisfies the following, amongst other user needs: 1) gaining visibility into the dynamics of their electronic business that is difficult to monitor today; 2) improve the profitability of marketing campaigns; 3) improve the return on investment in infrastructure systems; 4) improve the experience of customer relationships and monetize their value to the company.
[0131] A. Visual Sensor
[0132] The Visual Sensor gathers the desired information and data directly from the automated business processing system (e.g., the web server software in this embodiment). The data is then queued up for transmission to a Visual Server that is addressable on the network. The transmission channel, which uses the http protocol, is encrypted with SSL to protect the data from being intercepted. A Visual Sensor is installed on each web server that is a part of the same site and directed to send the collected data to the same Visual Server. Visual Sensor requires little or no oversight, unless configuration changes are made to the web server or network.
[0133] As discussed, each Visual Sensor captures data from the web server software and then writes it into a memory mapped file on the web server that serves as a storage queue for the periodic instances when Visual Sensor cannot contact Visual Server.
[0134] The data that is collected in the storage queue is forwarded to the Visual Server as fast as network conditions will allow. The connection to Visual Server is made to its port 443 , the same as a standard web server using HTTPS. The connection is encrypted using SSL to ensure that the data is protected en route to the Visual Server. The Visual Server receives the data and begins its processing and storage tasks. If the connection between Visual Sensors and Visual Server is broken for some external reason, Visual Sensor will queue up all data from the web server and transmit it when the connection is reinstated. The time that this information can be queued is based on the activity of the web server, but is usually 1 to 10 days. If the connection to Visual Server is not restored before the queuing disk space that is allocated on the web server is used up, data will be lost.
[0135] In the present example embodiment, the Visual Sensor is designed to support a web server (HTTP) data source. However, the Visual Sensor can be designed to support other types of data sources (other than HTTP) and transmit the data it collects and measurements it takes to Visual Server for processing and further transmission to Visual Workstation.
[0136] Visual Sensor is capable of additional services in addition to collecting and forwarding log data. For example, the Visual Sensor may take on additional system roles such as rewriting URLs or implementing an experiment on the HTTP server as is discussed below in detail.
[0137] The Visual Sensor can be configured to log HTTP traffic from an IIS or Apache server without performance impact on the server. In addition, a Visual Sensor API provides a standard for the creation of Visual Sensors for other systems.
[0138] The Visual Sensor software uses minimal resources of the web server. Under normal conditions the amount of processor power that is used is extremely difficult to measure. If the connection to Visual Server is for some reason severed, Visual Sensor will begin using its allotted data storage on the web server to prevent data loss. This queue size can be set from 1 MB to multiple GBs. Each visitor “click” requires approximately 300 bytes of storage space. For a server that receives 1,000,000 clicks in a day, the queue size would reach 300 MB in a day. In the case that a queue fills up with megabytes of data and the connection to Visual Server is then restored, Visual Sensor will as rapidly as possible transmit the queued data to Visual Server. In this “burst” mode Visual Sensor could take as much as 5% of the web server's processor power, which is generally insignificant as there is typically well more than 5% of excess processor power available from web server hardware.
[0139] In the present embodiment, the Visual Sensors are configured during installation.
[0140] B. Visual Server
[0141] The Visual Server is installed on the user's network and collects data from the Visual Sensors. After receiving the data, the Visual Server does the following with the data:
1. integrates the data from each of the Visual Sensors; 2. stores a copy of the data to disk in a compressed file format that can be re-read or used by other applications; 3. runs its transformation and data integration algorithms on the data that is collected; 4. transmits the transformed data to any authorized and available Visual Workstations; and 5. maintains a database of the transformed data in order that it can be re-transmitted to a Visual Workstation or transmitted to a new Visual Workstation.
[0147] The Visual Server application may be installed on any suitable computer system. The table below provides examples of two computer systems that are suitable for running the Visual Server application.
[0000]
Vendor
Dell
IBM
Model
Poweredge 2550,
2500SC
U Factor
Tower/2 U
2 U
Processor
>=1 Ghz
>=1 Ghz
Screen
15″ RGB LCD
15″ RGB LCD
Random Access Memory
512 MB
512 MB
Hard Disk Drive
80 GB
80 GB
Graphics Card
USB Ports
2
2
Ethernet Ports (100BaseT)
1
1
CD-ROM
Tape Back-up
DVD-ROM
Screen Resolution
Floppy Disk Drive
1.44
1.44
Link to Product Lit.
Pointing Device
Microsoft Optical
Microsoft Optical
Operating System
Windows 2000 Pro
Windows 2000 Pro
Microsoft Excel
Excel 2000
Excel 2000
[0148] Visual Server receives data from all Visual Sensors, combines it with other external data, processes it, and transmits it to Visual Workstations. Multiple Visual Sensors may provide data to one Visual Server Visual Server then processes the data coming from all of those servers. In the present example embodiment, there is preferably one Visual Server for each Web site. There may be many Visual Sensors, as each Web site may have multiple Web servers.
[0149] The Visual Server includes a Server Receiver (HTTPS Server) and a Processing Server. The Server Receiver provides communications with the Visual Sensors and also serves the purpose of processing requests from Visual Workstations.
[0150] The data collected by Visual Sensor is stored by Visual Server by date in compressed form, and can be exported to common log formats for use by other applications. In addition, Visual Server takes the stream of incoming log data and additionally processes it for use by a client application, such as Visual Site. This processing includes many types of processing, such as sessionizing the data, parsing URLs, and others.
[0151] In general, when a click gets added to the sample database by the Visual Server, some analysis or processing is performed. Information like whether this click starts a new session, or is part of an existing one, the duration of the click prior to this one (if any), and total session duration can be calculated. Furthermore, relevant dimensions are built up, such as target URL or Referrer. A dimension is a single vector of data points, into which a click or session has a reference. Clicks are inserted into the sample database by generating transactions.
[0152] The data is then organized into the data structure that supports Visual Workstation and the client application, and allows multi-dimensional analysis. The database that is created and updated by Visual Server is a custom relational database structure. The database resides in server memory with a persistent backup to disk in the form of a file, the current state of the Processing Server, and a transaction log of all transactions that have been generated to date for the database. The database is optimized for performance by allowing columns to be scanned very rapidly by indexing the actual location and order of the data in relation to the rest of the column of data.
[0153] The database has tables that have columns and rows. There is no hard binding between the tables. The order of the row in the column is the identifier of the position of the data in that column. In the present example embodiment, the database has the following tables for storing the following information:
[0154] Referrers
[0155] Pages
[0156] Clicks
[0157] Sessions
[0158] Visitors
[0159] Visitor Sessions
[0160] Zip Codes
[0161] Time Ranges
[0162] User Agents
[0000] Additional Dimensions add additional tables or columns.
[0163] At the top level, the database has the above tables. Each table defines the columns (fields) that are in it. The Sessions table has a click index column which points into the Clicks table identifying where the clicks from this session start, and has a click count to indicate how many of the next rows contain clicks from that session.
The Session tables have the following additional fields: A VisitorID which has a reference to the row in the visitor table; The timestamp for the session start; A pointer to the appropriate row in the referrer dimension; A duration column that gives the length of the session; A pointer to the appropriate row in the zip code dimension; A pointer to the appropriate row in the user agent dimension; and A field that is used to store intermittently produced value projections on the client. (The ‘value model’ in Visual Workstation computes a dollar value for each session based on the pages visited in the session and processes used by other sources when supporting other applications. This value is stored back into a column in the database for fast access.)
[0172] The Click table has a special allocator for performance reasons. It allocates memory for storage of clicks to improve resource usage and performance. It stores a list of free blocks inside its free blocks and assigns blocks based on order natural log(n). The Click table has references to the page dimension and the duration of the click. References exist as pointers to the row of the page dimension column.
[0173] One primary difference between this and a relational database is that relationships are built based on the allocation of space and position of the referenced element in the columns and, in the some cases, groups sets of clicks, for instance, keeping them in order so that you can start scanning at one point and just take the next N rows and know that you have the right data.
[0174] A statistical sample of the data is taken that represents the larger data set. This sample allows users to look at very large amount of data without transmitting all of the data to the Visual Workstation as is described in more detail below. Fact data that is left out of the sample can be retrieved from Visual Server at a later time if it is requested by a user. Fact data is the log data collected by Visual Sensor, provided to the Visual Server, processed and sampled to create the sample database. In the present example embodiment, the fact data would include all the information relating to particular sessions, users, and clicks, URL requests, etc., while the sample database would include a random sample of the fact data.
[0175] The Visual Server includes fault tolerant data queuing. Data is transmitted from collection points (e.g., Visual Sensors) across the Internet to Visual Server for combination, processing and distribution to Visual Workstations. The Visual Server queuing system can support system and network downtime without losing data. If a Visual Workstation or Visual Sensor is temporarily disconnected from the Visual Server, the Visual Server will resume transmitting (or retrieving in the case of Visual Sensor) once the connection is reestablished.
[0176] In addition, the Visual Server provides real-time data throughput including individual measurements, which become available to Visual Workstations while a customer session is still in progress. The Visual Server provides automatic updates to the Visual Workstations when connected to the network and no external database servers are needed to support Visual Workstation. The Visual Server scales to any size site with a single server.
[0177] Complete detailed records of collected data are compressed and stored indefinitely for future use. Visual Server's data store may be backed up through the use of a third-party secured and automated backup service. An agent runs on the Visual Server and incrementally backs up system software, operational databases and long-term input data storage to a secure data center. This backup service is optional as in-house corporate server backup procedures and systems can be used to accomplish the same backup procedure. No other administrative maintenance tasks are necessary for the Visual Server.
[0178] Visual Server's capacity for storing web server data in days is determined in the following manner:
1. System software requires approximately 100 MB of disk space. 2. The example client application (Visual Site) database requires approximately 10 GB of disk space. 3. The compressed web server log input files require storage space based on the number of web site visits and ratio at which Visual Server is able to compress the data for storage. The following is a typical example and summary for a mid-sized web site:
[0000]
Annual
Total
Operational
Compression
Storage
Storage
System
Database
Web
Ratio of
Compressed
Web
Requirements
Sofware
Storage
Server
Web
Storage
Days of
Server
(1
Requirements
Requirements
Data Per
Server
Per Day
Storage
data
Year)
(MB)
(GB)
day (MB)
Data
(MB)
Allocated
(MB)
(GB)
100
10
100
0.4
40
365
14600
24.7
[0182] The Visual Server includes a configuration file that permits the user to adjust the Visual Server settings.
[0183] C. Visual Workstation
[0184] The Visual Workstation is an integrated executive graphics workstation that allows users to immediately access, visualize and analyze up-to-the-minute information from a data source or set of data sources (such as HTTP or web sites with the Visual Site application). The Visual Workstation includes specific graphics hardware and RAM configurations to provide its highly graphical, high resolution interface. The Visual Workstation provides an underlying facility for running applications like Visual Site and receives data from the Visual Server. In addition, the Visual Workstation includes software for general operation of the workstation, such as operating system software and other software products necessary for utilization of the workstation hardware and software.
[0185] The Visual Workstation includes generic functionality that is used to support numerous applications (e.g., Visual Site) such as:
1. The ability to generate multiple visualizations in a user's interface. 2. The ability to group multiple visualizations into workspaces that scope queries. 3. The ability for a user to select parts of the visualizations to generate a query that the workstation query engine and data analysis facility understands. 4. The ability to save visualizations with their selections to persisted files that can be reloaded or messaged to others with the same dataset. 5. The ability for the workstation to connect to the server to gain access to incoming data that would update its local database.
[0191] The Visual Workstation includes a graphics engine that generates the user interface including hundreds of different graphical representations of data in the form of one dimensional, two dimensional, three dimensional, and multi-dimensional visualizations as well as spreadsheet like tables, line graphs, skatter plots, and others identified above.
[0192] Visual Workstation also includes a query engine that allows users to click on elements of visualizations that represent underlying data to subset or query the data that they are viewing. Users can select multiple elements in multiple visualizations to define advanced queries easily.
[0193] The Visual Workstation may include any suitable computer system. The table below provides examples of two desktop computer systems that are suitable for operation as the Visual Workstation.
[0000]
Vendor
Dell
IBM
Model
Dimension 8100
Processor
>1 Ghz
>1 Ghz
Monitor-Screen
17″ RGB LCD
17″ RGB LCD
RDRAM
512 MB
512 MB
Hard Disk Drive
40 GB
40 GB
Graphics Card
32 MB NVidia
32 MB NVidia Gforce
Gforce 2 MX
USB Ports
2
2
1394 (Firewire) Ports
1
1
Ethernet Ports (100BaseT)
1
1
CD-ROM
1
1
DVD-ROM
1
1
Screen Resolution
1600 × 1200
1600 × 1200
Floppy Disk Drive
1.44
1.44
Link to Product Lit.
Pointing Device
Microsoft Optical
Microsoft Optical
Operating System
Windows 2000 Pro
Windows 2000 Pro
Microsoft Office
Standard
Standard
Color of Unit
Black
Black
[0194] Alternately, the Visual Workstation may be comprised of a notebook computer. The table below provides examples of two notebook computer systems that are suitable for operation as the Visual Workstation.
[0000]
Vendor
Dell
IBM
Model
Inspiron 8100
Processor
>=1 Ghz
>=1 Ghz
Screen
15″ RGB LCD
15″ RGB LCD
Random Access Memory
512 MB
512 MB
Hard Disk Drive
40 GB
40 GB
Graphics Card
32 MB NVidia
NVidia Gforce 2 Go
Gforce 2 Go
USB Ports
2
2
1394 (Firewire) Ports
1
1
Ethernet Ports (100BaseT)
1
1
CD-ROM
1
1
DVD-ROM
1
1
Screen Resolution
1600 × 1200
1600 × 1200
Floppy Disk Drive
1.44
1.44
Link to Product Lit.
Pointing Device
Microsoft Optical
Microsoft Optical
Operating System
Windows 2000 Pro
Windows 2000 Pro
Microsoft Office
Standard
Standard
Color of Unit
Black
Black
[0195] The Visual Workstation in conjunction with the client application provides visualization and multi-visualization including rich, graphical presentation of multivariate data in high quality and frame rates. An arbitrary set of visualizations can be combined to visualize more variables. Visualization types include 1 and 2D bar graphs, tables, cross tabs, line graphs, histograms, timelines, site maps, geographic maps, terrain maps, fish eye lists, scatter plots, directed graphs, sales funnels, customer value pyramids, process flow, process performance plot, spaghetti plot, surface maps, 3D volume maps, 3D scalar fields, 3D vector fields, etc. Examples of such visualizations are shown in FIGS. 5-25 .
[0196] The information can be presented using numerous presentation techniques such as benchmarks, confidence intervals, color ramp metrics, dynamically filtered dimensions, scales and legends, trellis graphics, smooth transitions, moving average and kernel smoothing for line graphs, and others.
[0197] The Visual Workstation also provides a user interface with numerous interaction techniques such as data range selection, sliding window selection, normalize to series, water leveling, selection by water level, choice of series dimensions, move camera, drag, zoom and spin camera, mouse over to display values, context dialogs and menus, axis zooming, axis drilling, and others. Each visualization provides interactive selection techniques to filter the others allowing the user to visually slice and dice the data set.
[0198] The Visual Workstation also provides real-time remote viewing to remotely view and monitor (like cameras in a store) a business process and customers' interaction with them. In addition, the system provide real-time response as filtering and other user interface operations complete in about 100 ms or less allowing for animation of multiple on-screen visualizations.
[0199] The Visual Workstation also provides trend analysis allowing the use to view the complete history of any value by combining the timeline visualization with others. Derivative indicators (an arrow indicating consistent up or down trend of a particular value in a visualization) highlight values that appear to be following a consistent trend. The user may also annotate the timeline to cross-reference “real” world events, campaigns, outages, etc. that correspond with site activity to maintain accurate history.
[0200] One Visual Workstation can subscribe to multiple Visual Servers allowing its user to monitor and analyze multiple distinct sites or other data services (permitting multi-source data merging). As an example of the multi-source data merging of the present invention, data from a site can be merged with data from Nasdaq to allow the users of Visual Workstation to explore correlations between their operations and the movements of the markets. In addition, the user can perform a specification search for a selection to locate dimensions in which the current selection is unusual, thereby leading to the identification of causal events.
[0201] Clustering is implemented based on clickstream feature extraction. A large number of variables are generated and clustering techniques are used in the Visual Workstation to identify the important predictors. The objective is to classify sessions into groups so that the groups are (1) descriptive or (2) predictive of some variable or (3) both. The steps for implementing this feature include:
[0202] 1. Feature extraction—a variety of metrics are calculated about each session, e.g.,
a. number of clicks; b. number of different pages hit; c. number of different sections hit; d. duration; e. search used; f. number of product view pages hit; g. number of information pages hit;
[0210] 2. Cluster generation—a data mining algorithm is used to reduce the set of variables and then to identify a set of descriptive or predictive clusters. Each cluster becomes an element in a new dimension;
[0211] 3. Session clustering—Each session is assigned to a cluster according to the definition of the clusters;
[0212] 4. Investigation—The analysis features of workstations are used to examine the resulting clusters, decide how to name them descriptively, etc.
[0213] The Visual Workstation provides regression analysis modeling relationships between metrics (e.g., QoS, conversion rates, etc.). In addition, the user can explore models by creating decision trees, association graphs, scatter plots with trend lines for regressions, and other methods. Using logistic regression provides precise predictions of how changing page load times will change the probability of purchase.
[0214] Visual Workstation displays the English language equivalent of a complex query made by selecting points and areas on visualizations in a window on the screen, if so desired. It is easy to see from the English language descriptions of the actual selections that users are able to much more rapidly and effectively define queries or selections through pointing and clicking on well labeled visualizations than through any other method that does not require years of training.
[0215] Multiple Visual Workstations can be connected to Visual Server (in the method discussed below). In essence, once initial data is delivered to all Visual Workstations, only update information needs to be sent to them on an ongoing basis. This updating process puts a minimal load on the server and allows Visual Server to support many Visual Workstations. Specific calculations, which are well known in the art, can be run to determine this number based on a particular VOLAP platform configuration.
[0216] When the Visual Site application and the Visual Workstation that it is running on are disconnected from the network, the user can access all of the data that has been loaded into Visual Workstation up to that point. This enables the user to do perform the vast majority of tasks that he or she needs to, or would like to, do without being connected at all. The user, of course, will not receive incremental updates or real-time data feeds again until reconnected to the network.
[0217] 1. Workspace
[0218] A Workspace is an interface construct developed into Visual Workstation and is the basic unit of user activity in Visual Workstation—like a ‘document’ or ‘file’ in other applications. A Workspace allows multiple visualizations to be organized into one larger window to depict multiple related views of data that help a user understand and evaluate, in the case of Visual Site, a business process, a campaign, a segment of customers or some aspect of system performance. Each workspace belongs to a specific application (such as Visual Site) although multiple workspaces from different applications can coexist on the same Visual Workstation. Workspaces provide customizability, since a workspace can be created and saved to support some specific analysis task and Workspaces help to amortize the work of choosing and arranging visualizations over several uses. Thus, there is a tremendous amount of flexibility in how a Workspace may be organized and laid out on the screen.
[0219] A Workspace can contain any number and type of windows, including visualizations, other workspaces, and other objects such as text editors. In this sense, the Workspace acts like the “desktop” in a GUI operating system, except that there can be any number of them and they can be loaded and saved.
[0220] A novel interface technique is used to make arranging windows within a workspace easier. In most cases it is desirable to arrange a number of visualizations so that they do not overlap, but without wasting space. This is best achieved by having them (nearly) touch at edges A uniform spacing between windows is also aesthetically pleasing. The “smooth snap” technique makes this easy to do this without extreme dexterity with the mouse, but without restricting the set of window placements.
[0000]
[0221] This technique makes use of a mapping between a “placement space” which is 1:1 with the movement of the mouse, and the screen space in which windows are arranged A small box of pixels centered on a point or line the window snaps to is mapped to that point A somewhat larger box centered on the same point or line is mapped to itself. Points in between are mapped linearly; each pixel of distance in placement space is two in screen space. Sketch lines are displayed between windows to help the user see where windows will snap.
[0000]
[0222] A workspace is also responsible for integrating all the visualizations placed within it. Each visualization is controlled by two filters, “slice” and “benchmark”, and provides a third filter “selection.” In the preferred example embodiment, the following selection policy is used:
[0223] 1. Each visualization's benchmark is the workspace benchmark; and
[0224] 2. Each visualization's slice is the intersection of each other visualization's selection, and the workspace benchmark.
[0225] There is an efficient (O(N)) algorithm for computing this selection using bitfilters. Conceptually, this algorithm counts the number of visualizations selecting each row in the bitfilter table. It only needs to count to two, so it uses two bits rather than an integer per row:
[0000]
filter one = slice; // 0 if at least one widget doesn't select it
filter two = slice; // 0 if at least two widgets don't select it
for(int v=0; v<visualizations.size( ); v++) {
two &= selections[v];
two |= one;
one &= selections[v];
}
one = ~one; // 1 if at least one widget doesn't select it
for(int v=0; v<visualizations.size( ); v++)
if (changing_vis!=v) {
filter s = selections[v];
s {circumflex over ( )}= one;
s &= two;
visualizations[v]->setSlice( s );
}
[0226] Alternatively, another O(N) algorithm is available that will work on algebraic filters or bitfilters:
[0000]
static inline int parent(int x) { return (x−1)>>1; }
static inline int left(int x) { return x+x+1; }
static inline int right(int x) { return x+x+2; }
void updateSlices(int changing_vis) {
if (selections.size( ) <= 1) return;
int leaves = 1 << int( ceil( log(selections.size( )) / log(2) ) );
vector<filter> tree( leaves − 1 );
// see parent( ), left( ), right( ) functions for indexing
// Build bottom level of tree
for(int i=0; i<selections.size( ); i+=2) {
if (i+1==selections.size( )) { // Second visualization doesn't exist
tree[ parent(tree.size( ) + i) ] = selections[i];
} else {
tree[ parent(tree.size( ) + i) ] = selections[i] & selections[i+1];
}
}
// Build other levels of tree
for(int i=parent(tree.size( )−1); i>0; i−−) {
tree[i] = tree[left(i)] & tree[right(i)];
}
// We've built all the intermediate results, now we have to traverse them
// to generate the actual slices
int output = 0;
traverseSlice(tree, output, slice, 0);
assert (output == visualizations.size( ));
}
void traverseSlice(vector<filter>& tree, int& output, const filter& f,
int node) {
if (node >= tree.size( )) {
if (output < visualizations.size( ))
visualizations[output++]->setSlice(f);
} else {
int leftchild = left(node);
int rightchild = right(node);
if (rightchild < tree.size( ))
traverseSlice(tree, output, f & tree[rightchild], leftchild);
else
traverseSlice(tree, output, f & selections[rightchild-tree.size( )], leftchild);
if (leftchild < tree.size( ))
traverseSlice(tree, output, f & tree[leftchild], rightchild);
else
traverseSlice(tree, output, f & selections[leftchild-tree.size( )], rightchild);
}
}
[0227] Other selection policies are also possible. For example, a left-to-right selection policy could be used in an alternative embodiment of the Visual Workstation. In this alternative embodiment, the visualizations were arranged in a definite order in the interface. Each visualization's benchmark is the slice of the visualization to the left and each visualization's slice is the intersection of the slice and the selection of the visualization to the left
[0228] Another alternative selection policy is to let the user construct an arbitrary Boolean expression out of visualizations; for example by editing a directed acyclic graph with visualizations as nodes and Boolean operators (and, or, not) as edges.
[0229] Workspaces may also serve other functions. For example, they may act as “rooms” in a collaboration environment. Two users opening the same workspace on different workstations may use it together (with selections and other changes to the workspace being mirrored over the network on the other user's Workstation.)
[0230] In addition, Workspaces “scope” selections of data. All of the visualizations in a workspace are updated by selections made through interacting with one or more visualizations in that workspace. More specifically, in Visual Workstation a selection or query is scoped by the workspace, and any selections made by pointing and clicking on the visualizations to identify points and ranges on the visualization that represent parameters to be added to the query or selection. When a selection is made Visual Workstation immediately finds the data that matches the query and updates the other visualizations in the workspace with that data. The visualizations that are in other workspaces on a Visual Workstation screen are not updated by interactive selections made of visualizations within another workspace. Workspaces can also be saved and re-opened later. All of the visualizations, selections, notes, annotations and other information depicted within a workspace may be saved and returned to later for continued monitoring, exploration and evaluation.
[0231] Template Workspaces are resident on the Visual Workstation and provide a convenient starting point for a user to create Workspaces. Template workspaces lay out all of the visualizations and instructions for using them to accomplish a certain business task. Template Workspaces that are updated by the user can be saved and returned to later or used as a Template themselves.
[0232] Workspaces can be communicated between users for collaborative decision making. A Workspace can be e-mailed to another user that has the same database and be opened by that user and worked on. This allows a user to point out a correlation, insight, problem, or otherwise that they discover when monitoring, exploring or evaluating their business processes, campaigns, customer or system performance in the case of Visual Site to their team.
[0233] 2. Visualizations
[0234] All visualizations in Visual Workstation support a simple but powerful protocol that enables them to be used together with other visualizations. The first of these principal components of this interface is “filter getSelection(datatable& over).”
[0235] This function returns a filter describing the selection made by the user in the visualization. Every visualization provides a selection interface, which gives the user the ability to select some of the elements displayed by the visualization. The visualization uses the query engine to generate an appropriate filter from this selection and the given fact table.
[0236] The second principal component is “void setSlice(const filter& slice).” This function sets the slice of the visualization, a filter describing a subset of the data which is to be rendered by the visualization. The visualization may render only this data, or it may highlight this data so that it can be distinguished from data not in the slice.
[0237] The third function is “void setBenchmark(const filter& benchmark).” This function sets the benchmark of the visualization, a filter describing a set of data to be compared to the slice. A visualization may disregard the benchmark data, or it may render it in a way that can be compared with the slice data.
[0238] Visualizations also implement the drawable interface of the window system, so that they can be rendered as part of workspaces.
[0239] As discussed, the Visual Workstation provides an ever-expanding set of visualizations. Some of these can be and used with many different types of data, while others are specific to certain data as is well-known in the art.
[0240] 1D Bar graphs
[0241] 2D Bar graphs
[0242] 1D Tables
[0243] Crosstabs
[0244] Line graphs
[0245] 2D site maps
[0246] 3D site maps
[0247] 2D process conversion maps
[0248] Geographic maps
[0249] Session and click detail tables
[0250] 3D terrain maps
[0251] Fish eye lists
[0252] Scatter/bubble plots
[0253] Directed graphs
[0254] Sales funnel visualization
[0255] Customer value pyramid visualization
[0256] Spaghetti plot
[0257] Surface maps
[0258] 3D volume maps
[0259] 3D scalar fields
[0260] 3D vector fields
[0261] Page thumbnail sequences
[0262] Metric tables
[0263] Legends
[0264] Tree views
[0265] Certain presentation techniques are used across a variety of visualizations such as benchmarks. Benchmarks are a presentation technique designed to permit comparison of the slice and benchmark data described above. Essentially, the benchmark data is treated like another series of data, and displayed accordingly, except that it is automatically rescaled to highlight differences in distribution rather than in scale between the slice and benchmark sets. It is preferable to use a consistent presentation for benchmarks to aid the user in recognizing them. The figures show various screenshots to demonstrate use of benchmarks in different visualizations.
[0266] Confidence intervals are another presentation technique used across a variety of visualizations. Confidence intervals are an intuitive way of expressing statistical uncertainty. When a poll result is quoted as 54%+/−3%, this is a confidence interval. Confidence intervals are easier to understand than hypothesis testing (i.e. P-values) and do not require the user to articulate a hypothesis to the program. Visual Workstation displays confidence intervals so as to protect the user from inadvertently accepting results that have low statistical validity. The figures show various screenshots to demonstrate use of confidence intervals in different visualizations.
[0267] Color ramp metrics are still another presentation technique used across a variety of visualizations. Extra metric information can be displayed across almost any visualization by mapping it to color values. Visual Workstation maintains color ramp metrics at the Workspace level. Color ramp metrics are enabled by adding a special “Color Legend” visualization to a Workspace, which provides control over which metric to use. It is preferable to assign different color ramps to different metrics, so that it is easier to tell even without looking at the legend, what data is being represented as what color. In addition, the user may interactively threshold the metric by selecting ranges on the color legend. The figures shown various screenshots to demonstrate use of color ramp metrics in different visualizations.
[0268] Another presentation technique used across a variety of visualizations is dynamic filtering. Dynamic filtering is used to display data at the highest resolution that is statistically significant, but not permit it to degenerate into noise (or an impulse train).
[0269] Selection is a technique used across a variety of visualizations. Most Workstation visualizations support a common selection interface. Clicking on an element (with the user input device such as a mouse) selects it and deselects others. Clicking and dragging selects a range of elements and deselects others. Holding down the CTRL key modifies these behaviors to be “union” (other elements are not deselected). Holding down the SHIFT key modifies these behaviors to be “difference” (the chosen elements are deselected instead of selected). Holding down the ALT key and dragging “slides” the selection in any direction while maintaining its shape and size.
[0270] 3. Query Model
[0271] The query model provides an abstraction between visualizations and other ways of presenting or using data, and various ways that data may be stored and accessed. The key abstractions in the query model are dimensions, metrics, and filters.
[0272] As discussed above, a dimension represents a way of grouping data. Web log data, for example, can be grouped by month, by page, by visit, etc. Each “group” within a dimension is called an “element.” For example, a “Month” dimension would have elements “January”, “February”, etc.
[0273] A dimension represents only a conceptual grouping; it may or may not have anything to do with the physical representation of the data. This is in contrast to cube systems, where the term “dimension” is used in a similar way but a particular set of dimensions are a property of the structure of a cube.
[0274] It is not required that each piece of data fall into a single element. For example, a single session in web data may touch many pages, and so would fall into multiple elements in the page dimension.
[0275] It is possible to take the Cartesian product of any two dimensions to yield a third dimension. The number of elements in the third dimension is the product of the number of elements in the two dimensions. The Cartesian product operation can be visualized as a two-dimensional bargraph.
[0276] A discussed, a filter represents a subset of data. Filters support the Boolean (or set algebra) operations of union, intersection, and complementation. A filter may be represented algebraically, as an expression built up from subsets of dimension elements and boolean operations (e.g., Month=January and Hour=4:001
[0277] A filter may also be represented as a subset of rows in a table. This is sometimes called a bitfilter, since one bit is used for each row in the table (if the bit is one, the row is in the filter; if it is zero, it is not). This representation is very useful for fast evaluations over that table. Boolean operations on such filters are also quick.
[0278] A metric represents a function or calculation, which can be evaluated over a dimension and filter. Evaluating a metric over a given dimension and filter returns a result set of one floating-point value per element in the dimension. A result set might be returned as a table of tuples (element, value) instead of an array of values if many of the values are expected to be zero.
[0279] Any function of scalar values can be applied to metrics instead to yield another metric. For example, if f(x,y,z) is a function of three variables, and A, B, and C are metrics, then D=f(A,B,C) is also a metric, and can be evaluated by evaluating A, B, and C, and applying f to each triple of elements in their result sets.
[0280] More specifically, arithmetic operators such as addition, subtraction, multiplication, and division can be applied to metrics just as to ordinary numbers. For example, a “conversion rate” metric can be defined as (Purchases/Visits), where Purchases and Visits are metrics already defined.
[0281] Another operator available over metrics is filtering, applying an extra filter to an existing metric. For example, Purchases could be defined as Visits[Revenue>0] (pronounced “Visits where Revenue is greater than 0”).
[0282] The evaluation of a filtered metric is simply:
[0000] M 1[ F 1].eval(dim, filter)= M 1.eval(dim, F 1&filter)
[0283] More generally, any Boolean operation might be applied to a filter rather than intersection.
[0284] Metrics in the query model also have properties such as a name and a format (a format is a function that turns a numerical result into a usefully formatted string). Metrics can cache the results of previous evaluations, returning cached results unless the dimension, filter, or metric has changed. Any well-known caching algorithm could be used to cache results.
[0285] The abstract operations provided by dimensions, metrics, and filters are insufficient by themselves, because they provide no access to data. Operations to create primitive dimensions, metrics, and optionally filters are provided by a query engine. Visual Workstation can support many query engines including cubes, A-D trees, adapters to access other OLAP systems, as well as others. These primitive dimensions and metrics are used to create more sophisticated dimensions and metrics, and to create filters. Primitive and compound dimensions and metrics are different only in their implementation as they appear indistinguishable to the user and no explicit differentiation is made between them in the code.
[0286] The ‘opchains’ Query Engine (an abbreviations for “Operation Chains”) is a technique for multiple polymorphism that combines the advantages of “expression templates” (a well-known technique) with those of multiple dynamic dispatch techniques. Specifically, it permits the compiler to instantiate and optimize generic code for a particular situation (like expression templates), while allowing it to choose a code path at run-time (like dynamic dispatch) A sample algorithm is set forth in the Appendix.
[0287] This is possible because the compiler is caused to generate a large (but finite) number of different instances of the generic code, each optimized for a different case. It then chooses a code instance at run-time using dynamic dispatch. The compiler is induced to generate instances through a template metaprogramming technique.
[0288] In the preferred implementation, the set of items (“atoms”) to be dispatched on form a linked list or “chain.” This chain is built one atom at a time by the use of a function doubly dispatched on the type of the atom and the (arbitrarily complex) type of the chain:
[0000]
struct opchain_base : refcounted {
// Atoms to be composed
virtual opchain_base* v_cons( struct op_node& a ) = 0;
virtual opchain_base* v_cons( struct op_node_distinct& a ) = 0;
virtual opchain_base* v_cons( struct op_link& a ) = 0;
virtual opchain_base* v_cons( struct op_link_distinct& a ) = 0;
virtual opchain_base* v_cons( struct op_columndim& atom ) = 0;
virtual opchain_base* v_cons( struct op_count& atom ) = 0;
virtual opchain_base* v_cons( struct op_sum& atom ) = 0;
virtual opchain_base* v_cons( struct op_bitfilter& a ) = 0;
virtual opchain_base* v_cons( struct op_makefilter& a ) = 0;
// Other members also...
};
Once built, a chain has a type such as
op< A1, op< A2, op< A3, nil> > >
where
A1, A2, A3 are the types of the atoms in the chain
template<> op<Atom,Chain> is a subclass of opchain_base
nil is a subclass of opchain_base
[0289] The implementation of v_cons makes a decision (which can be decided at compile time) whether to extend the type of the chain or fall back on a dynamic implementation. This decision controls the set of chains generated by the compiler. For example (in this implementation):
[0000]
const bool use_dynamic =
T::dynamic ||
// Max 1 op_bitfilter, and it must be at the left
T::nFilters ||
// Exactly 1 metric in an expression
(X::nMetrics+T::nMetrics != 1) ||
// Dimensions must precede metrics
(X::nMetrics && T::nDims) ||
// Max # dimensions+metrics
(X::nDims+T::nDims+X::nMetrics+T::nMetrics > 3);
[0290] The op<Atom, Chain> template implements the operations to be composed by calling functions of atom templated on Chain. These functions can be inlined and statically optimized by the compiler, since they involve no dynamic dispatches or indirection.
[0291] Visual Workstation uses opchains to implement a query engine that works on data organized in tables with contiguous columns, supports several types of primitive dimensions including “column dimensions” represented by a column of integer keys mapping rows to dimension elements. Another type of primitive dimension supported includes “node dimensions” represented by an ‘index’ and a ‘count’ column of integers referencing spans of rows in a second table, a column of integer keys in the second table, and an array mapping these keys to dimension elements. Still another is “link dimensions” using the same representation as node dimensions, but mapping consecutive pairs of nodes to dimension elements instead of single nodes. In addition, alternative embodiments include modifications to support other types of dimensions which are represented over rows of a fact table.
[0292] Visual Workstation uses opchains to implement a query engine that supports several types of primitive metrics, including “count”, which counts the number of rows in a table falling into each dimension element, and “sum”, which sums the value of a given column over the rows falling into each dimension element. In addition, alternative embodiments include modifications to support other types of metrics, which operate over rows of a table.
[0293] Visual Workstation uses opchains to implement a query engine that can evaluate any combination of dimensions, metrics, and bitfilters and can generate bitfilters from a dimension and subset of elements.
[0294] The query engine uses several atomic operations including op_columndim, which implements column dimensions and op_node, and op_node_distinct, which implement node dimensions. op_node is used when the metrics being evaluated are in the secondary table and op_node_distinct is used when metrics are in the fact table. Others include op_link, and op_link_distinct, which are used to implement link dimensions; and op_count, which implements count metrics. Still other atomic operations include op_sum, which implements sum metrics over integer columns, op_bitfilter, which applies a bitfilter to the evaluation of metrics, and op_makefilter, which creates a bitfilter from a set of elements identified in a dimension.
[0295] The atomic operations used in the query engine contain additional architecture-specific optimizations such as, for example, cache warming and prefetching operations.
[0296] 4. Data Model
[0297] Data is organized hierarchically into databases containing tables containing columns containing rows. Tables contain some operations on rows (such as copying one row over another), which are automatically replicated across all columns All columns in a table always have the same number of rows.
[0298] Each column is represented as a contiguous array of homogenous type, with each element of the array containing the value of that column in one row. A column may contain elements of any type, but all of the elements in a column have the same type. This organization makes it very efficient to evaluate queries, which use only a few columns out of many.
[0299] The data stored in the data model may logically represent references between tables, such as that between a dimension column in a fact table and the corresponding column of strings naming the dimension elements, or the more complex relationship between the primary and secondary fact tables in a node dimension. However, these relationships are not explicit in the data model; they are understood only by the query engine. This means that operations at the data model level, such as the synchronization of databases across the network (transaction engine), need not be concerned with them.
[0300] 5. Metric spreadsheets
[0301] As explained above, metrics can be used like ordinary numbers in arithmetic expressions and functions. They can also support a variety of other useful operations such as filtering. It is therefore possible to create a spreadsheet which, in place of formulas involving numbers, contains formulas involving metrics. Each cell in such a spreadsheet may be blank, contain a label, contain an ordinary number, or contain a formula.
[0302] A formula in such a spreadsheet may reference named metrics from the query engine, may reference other cells, and may contain ordinary numbers. The result of any formula is a metric. Any metric can be evaluated over the null dimension to yield a number. This number may be displayed as the result of a formula in an ordinary spreadsheet would be displayed.
[0303] Selecting any cell (except a blank or label cell) in the spreadsheet yields a metric, which could be exported for use in any visualization or other client of the query engine. For example, one could graph any single cell over time.
[0304] Here is an example metric spreadsheet, showing formulas and labels:
[0000]
A
B
C
1
‘Search process’
‘
2
‘Searches’
Visits[ Page = “/search.asp” ]
3
‘Search results’
B2[ Page = “/search_results.asp” ]
B3/B2
4
‘Resulting sales’
B3[ Revenue>0 ]
B4/B2
5
‘Revenue from search’
Revenue[ Page= “/search.asp” and
B5/B2
Page= “/search_results.asp” ]
[0305] a. Here is the same spreadsheet showing values:
[0000]
A
B
C
1
Search process
2
Searches
28,200
3
Search results
18,500
84.1%
4
Resulting sales
2,200
7.8%
5
Revenue from search
$77,000
2.73%
[0306] Any of the cells containing a value could be used as a metric in other visualizations. For example, it might be very useful to see how revenue from search breaks down over time, over referring site, or other over dimensions.
[0307] The entire spreadsheet can easily be sliced by a given filter, simply by using the filter when metrics are evaluated to yield values that are displayed. This means it can support the visualization protocol described above and fit into workspaces as an ordinary visualization.
[0308] The usability of the spreadsheet could be further enhanced by providing automated functions for embedding tables over dimensions into the spreadsheet. For example, one could automatically insert a table into the spreadsheet giving Revenue from Search (B5) by Month.
[0309] 6. What-If Analysis
[0310] Visual Workstation's “What-If” Analysis technology helps a user answer a wide variety of speculative questions such as:
[0311] 1. “If 10,000 more people came to my site from yahoo.com, what would they do at my site?”
[0312] 2. “Would they generate enough additional revenue to justify a $5000 marketing expenditure at Yahoo?”
[0313] 3. “How much is improving the effectiveness of my product search process worth to me?”
[0314] 4. “What would happen if twice as many people looked at the special of the month?”
[0315] The analysis of past data can reveal correlations which, preferably augmented with human common sense, are useful in making predictions. What-If Analysis helps to automate this process.
[0316] a. Assumptions
[0317] All predictions are based on assumptions. What-If Analysis makes a single, broad assumption, which is referred as the uniformity assumption. In statistical language, this might be articulated as follows: All the records in any identifiable group are sampled randomly from the same population.
[0318] This means, for example, that if 45% of the mugworts in the database are feep, then 45% of all mugworts, or at least all the mugworts that can ever be in the database, are feep.
[0319] The uniformity assumption is not always correct. Consider questions one and two above. It may be that the people sent to the site by a marketing campaign at Yahoo will not be at all similar to the people who have visited the site from yahoo in the past, and there is no way for the program to know. The calculations made by What-If Analysis are only absolutely correct if both the past visitors from Yahoo and the visitors generated by the marketing campaign are chosen at random from the same set of yahoo's customers.
[0320] It is also important to realize that What-If Analysis does not distinguish correlation from causation. For example, there is a strong correlation between smoking and lung cancer. Consider this question: “If there were 10% more cases of lung cancer, how many smokers would there be?”
[0321] What-If Analysis would examine a suitable database and report that there would be an increase in smoking, since lung cancer cases are more likely to be smokers than the general population. This is, depending on how you look at it, a misleading conclusion: lung cancer doesn't cause smoking.
[0322] A simple way to think about this is that, given a what-if scenario, what-If Analysis calculates both the likely causes and effects of that scenario, but it is up to the user to distinguish one from the other.
[0323] b. Simple What-If Calculations
[0324] Consider question two above. Suppose it desired to answer this question by hand. One might reason as follows:
[0325] To date, 4000 people have been referred from Yahoo
[0326] The 4000 visitors generated $1000 in revenue
[0327] Each visitor, on average, generated $1000/4000=$0.25 in revenue
[0328] Since one assumes the 4000 previous visitors and the 10,000 hypothetical visitors are drawn from the same population, one expects each of the 10,000 visitors to generate $0.25 as well
[0329] 10,000 visitors will generate an additional $0.25*10000=$2500 in revenue
[0330] Thus, a $5000 investment is not justified
[0331] Note the importance of the uniformity assumption in this reasoning. Also note that if no one had ever been referred from Yahoo in the past, there would be no data on which to base this calculation.
[0332] The calculations used by Visual Workstation to perform the What-If Analysis are equivalent to those above, but they do not proceed in the same way. The method actually used generalizes better, requires less semantic understanding of the data, and is very efficient even for complex scenarios.
[0333] c. Scenario Model
[0334] Visual Workstation visualizations permit the user to describe a What-If scenario interactively in a variety of ways. For the purposes of analysis, these scenarios are represented as a collection of “hypotheticals” each having the form (X,G), where X is a number and G is a group. Each hypothesizes (X−1)*100% more records in group G. The scenario in the above example would be represented by a single hypothetical
[0000] (3.5, [Referrer=yahoo.com])
[0335] because in that scenario 14000/4000=3.5 times as many people came to the site from yahoo.com.
[0336] d. Record Weights
[0337] From the above scenario model, it is simple to compute a “weight” associated with each record. Initially all sessions have weight 1.0; each hypothetical (X,G) multiplies the weight of the sessions in G by X. Put another way, the weight of a session S under scenario H is defined as the set product
[0000] π{X|(X,G)εH and SεG}
[0338] From these weights W it is in turn possible to compute metrics such as counts and sums under the scenario, by replacing metrics as follows:
[0000] count->sum(W)
[0000] sum( C )->sum( W*C )=dot-product( W,C )
[0339] These can be efficiently evaluated by the Visual Workstation query engine. Count metrics become simple sum metrics, and sum metrics become dot products or sums of derived columns already multiplied by session weights.
[0340] e. Incremental Hypothesis Changes
[0341] In support of Visual Workstation's highly interactive user interface, it is important to be able to adjust just one hypothetical out of several and immediately recalculate the session weights. An operation is define:
[0000] changeWhatlfWeiglits(X1,X2,G)
[0342] which is defined to replace the hypothetical (X 1 ,G) with the hypothetical (X 2 ,G). The former must already be present in the scenario, unless X 1 =1.0.
[0343] The obvious implementation of this operation would be to multiply the weights of all the records in G by X 2 /X 1 . Unfortunately, because of the limited precision of machine arithmetic, a large number of such operations applied successively will not be reversible—it will be impossible to return exactly to the “null scenario” where all weights are 1.0.
[0344] This problem is currently solved by Visual Workstation by replacing multiplication and division with addition and subtraction of integral logarithms of weights, base 1.01. Since the numbers being added and subtracted are integers, commutativity is preserved and it is always possible to get back to the null scenario.
[0345] 7. Dashboard
[0346] A Dashboard is an interface construct developed into Visual Workstation. A Dashboard, is essentially a Workspace that allows real-time monitoring of multiple visualizations, metrics and dimensions to be organized into one larger window that is constantly updated with the latest information to depict progress toward key success factors. Dashboards allow managers, consultants and executives to monitor their business processes, campaigns, customer relationships and general site performance on a minute to minute basis.
[0347] Dashboards require no user interaction and allow for passive monitoring of critical business information. A default dashboard can be displayed automatically when a user is not actively working with a client application, to allow for the ongoing oversight of the business.
[0348] Dashboards can be saved and re-opened later All of the visualizations, selections, metrics, notes, annotations and other information depicted within a dashboard may be saved and returned to later for continued monitoring, either when selected or when other activity stops for a period of time.
[0349] Template Dashboards provide a convenient starting point for a user to create custom Dashboards Template dashboards lay out metrics, data dimensions, visualizations and instructions for what users might watch to understand their incremental progress toward key success factors Template dashboards that are updated by the user can be saved and returned to later or used as a Template themselves.
[0350] Dashboards can be communicated between users for collaborative decision making A dashboard can be e-mailed to another user that has the same database and be opened by that user for monitoring, this allows a user to point out a correlation, insight, problem, or otherwise that they discover when monitoring their business processes, campaigns, customer or system performance in the case of Visual Site to their team.
[0351] Printing visualizations is currently enabled by using screen shot-like capabilities. Data from visualizations can be printed by exporting it to Microsoft Excel, which is included with Visual Workstation
[0352] A saved workspace or visualization can be sent to another user of Visual Site via e-mail as long as they have the same site database updating on their Visual Workstation. The data behind most visualizations can be exported to Microsoft Excel to be printed in numerical report formats or for other analysis.
[0353] 8. Site and Process Maps
[0354] Site and process maps are used to display the session traffic, conversion rate, and potentially other metrics at each of a number of “nodes” (each a set of pages) and at each “link” between two nodes.
[0355] Maps can be created which (for example) display traffic over individual pages in a particular process, display traffic over the different sections of a site, or display traffic over the different subsections in a site section, by using different sets of pages to define nodes. In Visual Workstation, maps can be edited by the user using the following operations:
Drag and drop allows the user to position nodes on a map, and to add nodes to the map by dragging them from a hierarchical display of the available pages A node containing multiple pages can be expanded to one node for each page Two or more nodes can be collapsed to a single node containing the union of the pages in each
[0359] Maps can also be created by using a metric to determine the position of a node in one or more dimensions. For example, a “Process Conversion Map” positions each of its nodes at a horizontal position determined by the conversion rate from that node to the end of the process A node with 100% conversion is positioned at the right of the map, and a node with 0% conversion is positioned at the left. The vertical position of the node is determined by the user.
[0360] Once the set of nodes is determined, the program calculates the value of each metric for each node, and for each ordered pair of nodes (each link). For example, for each node the program calculates how many sessions visited any page in that node. For each ordered pair (n 1 , n 2 ) of nodes, the program calculates how many sessions navigated from a page in n 1 to a page in n 2 without visiting any other page in any node of the map. Using the Visual Workstation query model, all of this is done by evaluating each metric (Sessions, Conversion) over a single “link dimension” having one element for each node and one element for each ordered pair of nodes. This evaluation is always filtered by the “slice” filter assigned to the visualization by the workspace.
[0361] The metrics for each node are rendered by modifying the representation of that node. For example, in Visual Workstation's 3D maps, the metric Sessions is typically displayed as the height of a 3D bar (box) rising from the position of the node on a 2D plane. In 2D maps, the same metric is typically displayed as the area of a circle rendered at the position of the node. The metrics for each ordered pair of nodes are displayed using a representation stretching between the representations of the nodes in question. For example, in 3D maps, the metric Sessions is typically displayed as the cross sectional area of a “pipe” arching between the first and second nodes in the pair. In 2D maps, the same metric is typically displayed as the thickness and brightness of an arrow pointing from the first to the second node. In both 2D and 3D maps, Conversion or another metric is typically displayed by coloring each node's and each link's representation according to a legend mapping values to colors. (For example, a conversion of 0 might be drawn in yellow and a conversion of 1 in green, with intermediate values of conversion being indicated by colors intermediate between yellow and green). Additionally, metric values can be labeled textually over nodes and/or links.
[0362] 9. Value Model
[0363] Visual Workstation enables the user to analyze the value of pages, processes, marketing campaigns, and other entities in dollars even when a web site generates value indirectly through cost savings or offline transactions. The user of the software can identify actions on the site which generate value, and calculate the average value generated by a transaction of each type (for example, the user might assign a value of $50 each time a visitor uses a feature on the web site for finding an offline store, based on the marketing budget for bringing new visitors to the store). The user then specifies the url or urls corresponding to this transaction by dragging pages from a hierarchical display of pages into the “Value Model” visualization, and then enters the value ($50 in this case) assigned to the transaction.
[0364] The user can also quickly select a subset of the defined value events to make up the value model at any given moment. This makes it easy to analyze specific sources of value, or to view the data without a specific source of value.
[0365] Visual Workstation then defines a metric, Value, as the total of the assigned value of all the distinct selected value events that occurred in each session. This metric can be evaluated as a sum over the value of each session, where the value of each session is calculated in advance from the value model provided by the user. These values can be updated quickly by iterating over the distinct selected value events that occur in each session and summing their value.
[0366] Visual Workstation also defines a metric, Value Events, as the number of sessions in which any selected value event occurs. This can be implemented by a filtered count of sessions (for example, sessions where Value is nonzero).
[0367] Visual Workstation also defines a metric, Conversion, as Value Events/Sessions, where “Sessions” is a metric counting the number of sessions. Conversion is expressed as a percentage (e.g. 13.2% of sessions had at least one value event).
[0368] 10. Path Browser
[0369] Like a site map, path browser analyzes traffic and other metrics over a set of nodes (each one or more pages). The set of nodes also includes an “entry” node, which contains no pages but is considered to be visited just before the first page visited in a session, and an “exit” node, which contains no pages but is considered to be visited just after the last page visited in a session.
[0370] The path browser displays a currently selected “path” consisting of an ordered list of one or more (not necessarily distinct) nodes. This path is represented using a representation for each node (such as a text label, an icon, etc), with each consecutive pair of nodes connected by a representation of a link, such as a line or arrow.
[0371] The sessions which visited each of the nodes in the path in sequence, without visiting any node not in the path in between two of the nodes in the path, are considered the sessions selected by the visualization. In Visual Workstation, the visualization makes this set of sessions available to the workspace as its selection filter.
[0372] Unless the first node in the path is the “entry” node, which is not preceded by anything in a session, each occurrence of the selected path in a session will have a “previous” node: the last node that occurs in the session before the occurrence of the path. The program calculates the number of occurrences for each previous node, and may calculate other metrics over the set of occurrences or sessions. The set of nodes is sorted by the number of occurrences of each as a previous node, and the top N such nodes are displayed. Typically the previous nodes are represented in a manner similar to the way the nodes in the currently selected path are represented, except that since they are alternative rather than sequentially visited nodes they should preferably be displayed at intervals orthogonal to the intervals between nodes in the selected path. For example, if the selected path is displayed horizontally, with earlier nodes in the sequence to the left and later nodes to the right, the most frequent previous nodes might be displayed to the left of the leftmost node in the sequence, with the most frequent node at the top, the next most frequent node below it, and the least frequent node at the bottom.
[0373] The next node is displayed in a similar fashion. Unless the next node in the selected path, which is never followed by anything in a session, each occurrence of the selected path will have a next node: the first node that occurs in the session after the occurrence of the path. The program calculates the number of occurrences for each next node, and may calculate other metrics over the set of occurrences or sessions. The set of nodes is sorted by the number of occurrences of each as a next node, and the top N such nodes are displayed. If the selected path is displayed horizontally, with earlier nodes in the sequence to the left and later nodes to the right, the most frequent next nodes might be displayed to the right of the rightmost node in the sequence, with the most frequent node at the top, the next most frequent node below it, and the least frequent node at the bottom.
[0374] A link representation similar to the links between consecutive nodes in the path may be used to connect the first node in the path to each of the previous nodes, and the last node in the path to each of the next nodes.
[0375] The program may display metrics for each previous and each next node. For example, it might display the number of occurrences of each as a previous or next node, or the fraction of occurrences of the path in which each occurs. It may also display metrics for the selected path as a whole.
[0376] To actually calculate the numbers of occurrences for each previous or next node, the program may use a path dimension having one element for every possible path (every possible list of nodes—this is an infinite number of elements). A derived dimension may be created from such a dimension (by taking a subset of elements) having one element for every possible path which consists of any single node followed by the currently selected path (which is also one element for each node, so this is a finite number of elements). Evaluating a metric over such a dimension yields the value of the metric for each previous node.
[0377] Similarly, evaluating a metric over a dimension having one element for each possible path which consists of the selected path followed by a single node yields the value of that metric for each next node.
[0378] Alternatively, metrics such as the “number of occurrences” metric may be evaluated directly from a list of pages visited in each sessions. First the list of pages is transformed to a list of nodes visited in each session using the definition of the set of pages for each node. Then, for each session, the list of nodes is searched for a sublist equal to the currently selected path (using any string search algorithm). The number of occurrences, the number of occurrences for each previous node, and the number of occurrences for each subsequent node can then be counted directly from the set of occurrences found by the string search.
[0379] These steps may all be performed in one pass over the list of pages visited, by looking up each page in a table to yield the corresponding node as the list is traversed by the search algorithm.
[0380] The user should be enabled to interactively edit the list of nodes in the path. An easy way for the user to add nodes to either end of the path is to select one of the previous or next nodes (for example, by clicking it with the mouse). If the user selects a previous node, the program can insert this node at the beginning of the list of selected nodes. If the user selects a next node, the program inserts that node at the end of the list of selected nodes. The user must also be able to remove a node from the list if more than one node is present (leaving the order of the other nodes unchanged). The user should also be able to add arbitrary nodes to the list (for example, by choosing them from a list of all nodes, or dragging them from elsewhere in the interface). Whenever any change is made to the selected path, all of the calculations and displays above must be updated to take into account the change.
[0381] A path browser needs to be initialized with a currently selected path of at least one node. This node can be the entry node (in order to show the behavior of visitors beginning with their arrival at the site), it can be the exit node (in order to show the behavior of visitors before they leave the site), or it can be another node selected by the user from another visualization such as a site map or list of pages.
III. Operation of System Components
[0382] A. Visual Sensor
[0383] Visual Sensor, which is comprised of a plurality of software modules being run on (or in communication with) the web server, collects information about each click from web users accessing the web site. For IIS, the collection mechanism used is an ISAPI filter. For Apache, it is a dynamically loaded module. Identical information is collected on each platform by Visual Sensor's Logging process and placed in a circular disk queue.
[0384] In the present example embodiment, when a user clicks a URL in a web browser the request is transmitted to the web server. The web server reads the request and processes it by serving back pages, static or dynamic. When that request is registered by the web server, Visual Sensor's Logging process capture the requests, stores it and a circular queue, and Visual Sensor's TXLog process transmits the request to the Visual Server.
[0385] The following are examples of two sets log data that might be stored by the Visual Sensor.
Example 1
[0386]
[0000]
CLogEntry Dump:
Status: 200
TrackingFlags: 1
TrackingID: 4306072366534025577
ServerTime: Mon Oct 08 20:00:00 2001
URI Stem: /Default.asp
URI Query:
Client Host: 63.78.56.226
Server Host: 172.16.0.20
Referrer:
Cookie:
User Agent: WhatsUp_Gold/6.0
Example 2
[0387]
[0000]
CLogEntry Dump:
Status: 200
TrackingFlags: 0
TrackingID: 4306065223016891024
ServerTime: Mon Oct 08 20:00:00 2001
URI Stem: /direct.asp
URI Query: idpage=bnk
Client Host: 64.210.241.103
Server Host: www.everbank.com
Referrer: http://www.everbank.com/v24topnav.asp?IdPage=pro_bill_t1
Cookie:
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1&repID=&IDAff=1&bFreeSourceID=
00379007964559282166&IDAffAlias=eb&version=v24;
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User Agent: Mozilla/4.0 (compatible; MSIE 5.5; MSNIA; Windows 98;
Win 9x 4.90)
[0388] Most of the information in the above examples of log data is convention log data and, therefore, not repeated here. Further examples of log data are provided in the Appendix.
[0389] The circular queue is a fixed size file on disk that is, logically, a circular list that wraps around on itself and overwrites itself when full. More specifically, after data about the click is collected it is pushed onto the back of the circular queue stored on disk. The queue uses a fixed amount of disk space with each new entry being placed at the end of free space. When the end of free space is reached, it wraps around and the next entry is placed at the beginning of the queue. This is important because it prevents unbounded growth of the queue. It is important the Visual Sensor be unobtrusive and cause no difficulty for the web server. A disk queue that has the potential to grow without bounds could use all free disk space and bring down the web server. Another advantage of the fixed size is that there is never any need to acquire and release free storage space. This acquire/release cycle that is typical of queues and lists can be the most computationally expensive aspect of the program.
[0390] This queue also requires no synchronization between a writer and reader. Usually, when there is a writer and reader of a common piece of shared storage there is inefficient synchronization that must occur between the two processes to insure that the writer does not overwrite data that has not been read and that the reader does not read data that is incomplete. This synchronization typically involves one process sitting idle until the other has completed its task. The disk queue of the present invention does not require this inefficiency.
[0391] The web server and Visual Sensor are done with the data after it has been pushed onto the queue. Next, the click data is ready to be picked up by the TXLog process that will transmit it to the Visual Server for permanent storage and analysis. The TXLog process pulls entries from the queue, wraps them up as an SSL encrypted HTTP request, and sends them over the network to the Visual Server.
[0392] The TXLog process constantly looks for data in the memory mapped file that stores the logged data (collected from web server by the Logging Process) and if there is any, makes a request of Visual Server and sends the data to the Visual Server. The TXLog process attempts to send 8 Kbyte packets, although if there is more data to be sent, it sends larger packets. The TXLog process can be throttled as an overall process to limit the amount of bandwidth when transmitting data to the Visual Server. This TXLog process is completely independent of the web server and continuously monitors the queue for new entries. In addition, the TXLog process can transmit data placed there by any cooperating process.
[0393] As discussed, the ISAPI filter for IIS and module for Apache use different mechanisms but log the same data. In addition to logging data, each places a cookie, as is well-known in the art, on the customer's computer system (customer refers to the visitor accessing the web site) so that customer will be recognized in the future. In the present example embodiment, the cookie stores an identifier that uniquely identifies the customer's computer and, in some alternative implementations, identifies the computer being used by the customer.
[0394] Visual Sensor also provides a mechanism that allows the web developer to submit user specific data for analysis. This data may be static or dynamically generated by the processing logic on the web page. However, there are limited facilities available for communicating between the logic of a web page and our web server hooks for logging. In one embodiment, a custom object or service allows submission of additional logging information. There are, however, a number of drawbacks with approach. First, the web developers must learn and use yet another interface. Second, the approach requires additional installation and configuration procedures. Third, the process can only be invoked in a script and there is no way to statically log information through links or Universal Resource Locator's (URL's).
[0395] The preferred approach is to permit add logging data to the URL query string. As is well-known in the art, the query string is the string of name/value pairs that is after the “?” in a URL (i.e., http://www.foo.com/mypage.asp?firstname=dylan&lastname=ginsburg). The web developer uses the facilities of the web development environment to add additional name/value pairs to the query string. This avoids the problems associated with the first approach discussed above. Specifically, the first and second problems are avoided because this solution requires no additional software other than what is already available in the web development environment. In addition, the approach provides a consistent solution to third problem because it allows information to be added to the query string dynamically from page processing logic as well as allowing data to be collected from static links.
[0396] In operation, when data is sent to the Visual Server the query strings following the ? in the URL are parsed and separated into <Name=Value> pairs or tuples. Each unique combination of query strings names and values along with the base URL can be considered a separate page by Visual Site. In the majority of cases a relatively small number of these combinations may actual be pages in the site. These dynamic pages can be treated as unique logical pages for analysis in Visual Site and can be collapsed together or expanded into different logical groupings.
[0397] This ability to capture user specific data through the normal process facilitates providing actionable business intelligence to the user in almost any specific area. For instance, zip codes data could be added to the log data (provided the customer's zip code was provided by the customer). The name of a page that is dynamically generated could be added. The amount of a purchase could be stored in the log file. The items referenced on pages that a visitor viewed or added to their shopping carts could be stored. This data is not normally available through logs. However, once stored, subsequent processing would permit removing this data from the logs and adding it to the dimensions kept in the database or performing whatever other processing is desired by the user.
[0398] One example of capturing user specific data will now be described for the Microsoft IIS platform. Microsoft's ASP platform permits the use of the “Response.AppendToLog” command, which modifies a query string transmitted by a browser as is well-known to those skilled in the art. As discussed, Visual Sensor captures the query string, and logs the name/value pairs in the URI Query field for subsequent transmission to Visual Server, which parses and filters the query strings.
[0399] The following is an example implementation of a method of capturing user specific data as described above for ASP pages. The following code is placed at the top of an ASP page (or anywhere in the page if buffering is enabled, which is the default for IIS):
[0000] <% Response.AppendToLog “page=” & Server.URLEncode(page_name) %>
[0400] where “page_name” is a variable containing the name of the actual page being served. Response.AppendToLog actually appends information to the query string that is used for logging. Preferably, the file.asp page always receives POSTs so that the query string is always initially empty.
[0401] To capture product information by appending product identifying information to the end of the URL, the following code is added for each product on the first page of the purchase process after the user checks which products they want:
[0000] <% Response.AppendToLog “&select_prod=” & Server.URLEncode(product) %>
[0402] where “product” is the name or other identifying information of the product that the user has selected for purchase, but for which the purchase process has not yet been completed.
[0403] In addition, it is preferable on the checkout page to add similar code, but with a different variable name such as:
[0000] <% Response.AppendToLog “&purchase_prod=” &Server.URLEncode(product) %>
[0404] By capturing the “selected” product and the “purchased” product, it is easy to compute and collect data relating to products that were selected, but were not purchased by the customer.
[0405] To capture zip code data, the following code should be added to the appropriate appwizard process:
[0000] Response.AppendToLog “&zipcode=” & Server.URLEncode(zipcode)
[0406] The techniques used for permanent logging of the data in the present embodiment are well-known in the art and are, therefore, not repeated here. The communication link employed between the Visual Sensor and the Visual Server in this embodiment is the well-known HTTP protocol and, therefore, is not detailed here. The HTTP protocol is used to frame the present embodiment's internal data transmission format. HTTP is most commonly used to send HTML text that is rendered by a browser. However, the HTTP protocol is flexible enough to serve as a frame for any arbitrary data. There are several benefits realized by using HTTP instead of a proprietary protocol, which could be used in an alternative embodiment. First, HTTP protocol is firewall and proxy friendly. Second, the Visual Server is a web server that can communicate with a browser for data collection. This means that, if necessary, the Visual Server could communicate directly with the customers' web browsers via HTML image tags or cookies. In addition, if necessary, an agent could be put on the customer's computer that will communicate with the Visual Server using HTTP and standard ports. Third, HTTP protocol permits easier interoperability with other systems. Future applications that wish to submit to or receive data from the Visual Server should be easier to implement since HTTP is a ubiquitous protocol. Web browsers can be served directly allowing for a thin client. SOAP and XML are easily integrated to allow the present embodiment to present a standard Web Service interface for accepting data.
[0407] What makes this architecture atypical is the inherent fault tolerance provided by it's disconnected and loosely coupled nature. The system is comprised of a series of collection points separated by persistent disk storage (the Visual Sensor disk queue, the Visual Server database, and the Visual Workstation database). Each process can be ignorant of the other and only cares that it can pick up data from a known location on disk. This architecture prevents permanent damage and loss of data is lost should a component go down or the network link is unavailable.
[0408] As discussed above, the Visual Sensor may take on additional system roles such as rewriting URLs or implementing an experiment on the HTTP server. To accomplish either of these tasks, the Visual Sensor first takes a URL that is requested by a browser of the site and replaces that URL with a different URL that is then process by the web server. For example, if a customer requests home page version one, Visual Sensor could give the web server the URL for a different home page—home page version two—to process for the browser. Visual Sensor can provide a different URL for any percentage of requests for a page (for example, providing a different URL every third request for a particular URL). Regularly providing an alternative URL after every a fixed number of requests for page (e.g., 3), allows the user to test a new page on a limited number of customers to determine if the new page performs statistically better than the existing page.
[0409] Through this periodic substitution process (substituting an alternative URL every X pages), Visual Sensor permits the user to experiment with new pages to refine and improve the automated processes. In addition, this periodic substitution process may be repeated for multiple pages that are a part of a customer's session. For example, the periodic substitution process would allow the user to test Checkout Process number two (which includes multiple web pages) to see if it performs statistically better than Checkout Process number one. By allowing users to test a new process, (e.g., showing it to one of every 1000 visitors) the user can determine if the tested process performs better than the existing process(es).
[0410] In one method of performing the periodic substitution process, each customer is assigned to a different experimental group (e.g., the test process group or existing process group) at random, using given weights for what percentage of visitors fall in each group. Each customer stays in the same group for each experiment, but is assigned independently to different experiments. Capturing this information in the log is accomplished by hashing the visitor ID together with the experiment ID to get a pseudo-random number, which is then compared against the percentage weights.
[0411] As discussed above, the Visual Sensor of the present example embodiment captures data from a web server. However, rather than taking log data from a web server, the Visual Sensor could take log data from a telecommunications switch, a network router, a database, an application's logging facility or other source by customizing the collection element of the Visual Sensor for that other data source. The other functionality of the sensor including the ability to queue and transmit securely the data remain largely unchanged structurally, although different data would be collected, stored, and transmitted.
[0412] B. Visual Server
[0413] The Visual Server is an HTTP server that logs clicks sent by the Visual Sensor as well as any other HTTP requests of interest. These log entries are picked up asynchronously by a Processing Server that statistically samples the data and transforms it into a form palatable for the Workstation.
[0414] Visual Server receives the data that is being transmitted to it by each Visual Sensor that is installed. Visual Server receives the data, combines it chronologically with the data from other Visual Sensors, then stores it off to disk in the form of compressed files and continues to use it for real-time data processing. The compressed files are stored to disk by date and named so that they can be easily re-used. The files can be exported to standard log file formats that might be used by other applications. Periodically the files that are stored on Visual Server are backed up to tape or long-term network storage.
[0415] 1. Log Sources
[0416] The processing service is configured to read a sequence of log files. Thus, with two web servers, two sequences of files would be generated by the Visual Sensors and Server Receiver.
[0417] The Server Receiver is a proprietary HTTPS server, which is a part of Visual Server. Visual Sensor transmits data to the Visual Server by making a request of the HTTPS server and transmitting data along with that request. It can be located at a customer location or otherwise. It requires network accessibility, but it could be anywhere on the Internet as long as enough bandwidth is available.
[0418] The two sequence files would look like this:
[0000]
20010818-24.168.212.55.log
20010818-24.168.212.57.log
20010819-24.168.212.55.log
20010819-24.168.212.57.log
20010820-24.168.212.55.log
20010820-24.168.212.57.log
[0419] The Processing Server is configured with a list of filename masks. Using the example above the following entries would be found in the config.vsc file:
[0000] SequenceMask=−24.168.212.55.log
[0000] SequenceMask−24.168.212.57.log
[0420] Each sequence of files is treated as a source and there is always at least one source corresponding to at least one web server. In the case of multiple sources, clicks are popped off of each source in chronological order across all sources. That is, assuming clicks c 1 , c 2 , c 3 , and c 4 are in chronological order, and that c 1 and c 3 are in source 1 and c 2 and c 4 are in source 2 , the clicks will be processed in the correct order of c 1 , c 2 , c 3 , and c 4 through processing by an algorithm.
[0421] 2. Click Processing
[0422] The Visual Server processes each click by discarding HTTP error clicks or saving save them (depending on if they are listed as needing to be saved in the configuration files). Next, the click is checked against a (configurable) list of robot user agents (crawler, sitemonitor, etc). If the click is recognized as that of a robot based on a table of definitions of such parties in the configuration files, then it is discarded. Next, clicks corresponding to particular URL paths, which have been specified in the configuration file, are discarded.
[0423] Next, the click is first checked to see if it is a new (first time) visitor to this site by looking at the new visitor tag generated by the Visual Sensor, which determines if it is a new visitor based on whether or not the cookie matches a cookie previously received.
[0424] If the visitor is a new visitor, the actual number of visitors that have visited the site is incremented. In addition, if the visitor was a new visitor, then statistical sampling occurs.
[0425] If the sample is not full (as specified by a size limit based on the number of visitors in the configuration file) the sampling process adds the click data to the sample database. If the sample is full it executes, a statistical random sampling algorithm is executed to determine whether or not to replace an existing entry in the sample with that visitor data.
[0426] Once a sample is full, the chance that any new visitor click gets put into the sample is the same as any other new visitor click. A new visitor click that is put into the sample replaces a random one that was already in the sample, in this case. The number of visitors in the sample is configurable in the configuration file (as is shown in the sample below).
[0427] If the click is a returning visitor, then the sample is checked to see if this visitor is in the sample yet. If the returning visitor is already in the sample, then this click is added to the sample. If the returning visitor is not already in the sample, the click is discarded.
[0428] Next, the click is sessionized so that if the visitor does not have an already and existing visitor session in progress, then the process create a new visitor session. If a new session is created, then the process parses the referrer and creates a transaction that updates the referrer dimension. If a visitor session does already exist for the visitor, then the process determines if the received click data belongs to that session by looking at the time difference between the received click data and the last click (the duration for the time between clicks to be in the same session is defined in a configuration file entry) by that visitor and by checking to see if the referrer of the click is an internal (to the site) referrer.
[0429] Next, the URL that the user clicked is parsed out to build the page dimension. If the page already exists in the page dimension then the process references that page to the click and if the page does not already exists in the page dimension, then the process creates a transaction that adds that page to the page dimension.
[0430] When parsing the URL and the query string that is included in the URL, the process determines whether any name=value pairs in the query string were present where the name matches a name defined in our configuration file. If one is found that matches, the process determines if that value already exists in the target dimension as defined by the name and the configuration file. If that value exists in the target dimension, then the process gets the key to the element in the dimension. If that value does not exist in the target dimension, then the process creates a transaction to add the value to the target dimension in the database. If the element has already been bound to the target dimension at a session level then nothing need be done. If the element has not been bound to the target dimension, the process creates a transaction that binds the click to that dimension.
[0431] a. Sampling
[0432] Data collected from web servers is very significant in size, for instance, if a site served one million (1,000,000) page requests a day over 3 Gigabytes of data would be collected, over a year's time that would mount to over 1 Terabyte of data. The multiple gigabytes and terabytes of data in an operational database are expensive, both from the financial point of view and from the system point of view. An operational database that could store and search that amount of data would cost in the millions of dollars. Even if companies chose to make such expenditure, searches against that data would take minutes if not hours to run, making it impossible for data consumers to rapidly explore the data they have collected, or do any significant analysis on it without letting a query run for hours and then produce its result. The present invention permits analysis of these large amounts of data where the laws of physics and the state of database, system and network technology will not presently allow. In fact, the present invention permits users to analyze these vast amounts of data interactively, in real-time.
[0433] This problem (the management of terabytes of web data) is solved by building a random sample of the entire population of visitors that visit the web site and incrementally updating that random sample over time. The main idea behind the statistical inference enabled by sampling is to take a random sample from the entire population of visitors to the site and then to use the information from the random sample to make inferences about particular population characteristics such as the mean (measure of central tendency), the standard deviation (measure of spread) or the proportion of units in the population that have a certain characteristic. Sampling saves money, time, and effort. Additionally, a sample can, in some cases, provide as much or more accuracy than a corresponding study that would attempt to investigate an entire population-careful collection of data from a sample will often provide better information than a less careful study that tries to look at the whole population. In general, the larger the sample is in relation to the overall population, the higher the probability that a selection of the sample or a calculation based on the sample would correspond to that selection of calculation done against the entire population. The typical sample size used by the Visual Site application is one million visitors, including all of their sessions, and activities. For some sites this is a very large sample and for others, just a large sample.
[0434] Because a sample examines only part of a population, the sample mean will not exactly equal the corresponding mean of the population. Thus, an important consideration is the degree to which sample estimates will agree with the corresponding population characteristic. Understand that estimates are expected to differ from the population characteristics that are trying to be estimated, but that the properties of sampling distributions allow quantification, probabilistically, of how they will differ. In other words, the sample or sub-sample used to infer information about the entire population is slightly less accurate than a count of the entire population would be and the probability that a sample's inference is a correct representation of the whole population falls within a known probability range. When very small selections are made of the sample, the probability that they will correspond to the entire populations decreases, In the present invention, users are informed about where the sample lacks statistical confidence by a “Confidence Interval” display provided on the Visual Workstation, which lets users know were they should lack confidence in the results they are shown.
[0435] The following example illustrates the potential error factors or “accuracy” of the statistical sampling techniques used:
1. For the purposes of this example, assume that the size of the random Sample of visitors is fixed at 1,000,000 (N) of the total visitor population of site which is at up to this time, 100,000,000 or (V); 2. Assume that the user of the application Site selects 100,000 (X) visitors in the sample or (10%) of the sample's visitors to analyze or view by clicking on visualizations; 3. Sampling allows one to multiply (X) by (V/N) or 100 to infer the number of visitors (Y) or 10,000,000 in the overall population that have selection criteria equivalent to (X) in the sample; 4. Given these assumptions, there would be a 95% chance that the 10,000,000 visitors (Y) selected through the sample as (X) and multiplied by (V/N) or 100 to infer into the total population of visitors, are representative of between 99.4% and 100.6% of (XV), or the Actual Set of Visitors in entire population that meet the criteria of selection (X). 5. Further, selections of visitors of the following sizes, and the inferences based on that sample about the overall population would have the below listed potential percentage errors and accuracies in relation to the actual entire population:
[0000]
There is a 95%
Chance That
There is a
The Distinct
95%
Set of Visitors
Chance
(XV) in
That
Population (V)
The
the
that are
Percentage
Inferred Set
Error
Inferred by
of the
of Visitors
in This
Selection Set
Visual
Based on
Inference
(X), is in this
Site
Selected
Selected Set
(Y)
percentage
There is a 95% Chance
Sample
Set of
in Sample
is Less
range of the
That The Distinct Set of
Selected
Visitors
(X), if
Than +
Number of
Visitors (XV) in
Sample
by User
Represented
Visitor
or −
Visitors
Population V that are
Visitor
Size Used
of Visual
in
Population
this
Inferred From
Inferred by Selection Se
Population
By Visual
Site
Sample
is (V) is
(%),
the Sample as
(X), as (Y), is Between
of Site (V)
Site (N)
(P)
(X)
(Y)
and
(Y), or
These Absolute Number
100,000,000
1,000,000
100.000%
1,000,000
100,000,000
0.00%
100.0%
100.0%
100,000,000
100,000,000
100,000,000
1,000,000
50.000%
500,000
50,00,0000
0.14%
99.9%
100.1%
49,930,704
50,069,296
100,000,000
1,000,000
33.000%
330,000
33,000,000
0.23%
99.8%
100.2%
32,924,562
33,075,438
100,000,000
1,000,000
10.000%
100,000
10,000,000
0.56%
99.4%
100.6%
9,944,217
10,055,783
100,000,000
1,000,000
1.000%
10,000
1,000,000
1.94%
98.1%
101.9%
980,596
1,019,404
100,000,000
1,000,000
0.100%
1,000
100,000
6.19%
93.8%
106.2%
93,808
106,192
100,000,000
1,000,000
0.010%
100
10,000
19.60%
80.4%
119.6%
8,040
11,960
100,000,000
1,000,000
0.001%
10
1,000
61.98%
38.0%
162.0%
380
1,620
[0441] Client applications, such as Visual Site, depict the accuracy level of the data that is displayed in visualizations by showing a confidence interval through making the value in the display “fuzzy” or diluted in color, in proportion to the potential for error in the inference made by a selection of the random sample.
[0442] It is clear from the example above that the data inferred by client applications, such as Visual Site, is very highly accurate with larger selections and becomes less accurate and the depictions of the data become more fuzzy as the user's selected part of the sample (X) becomes very small. In other words, client applications, such as Visual Site, are highly accurate until the selection sizes become less than 0.1% of the sample. A major exception to this lies in the fact that client applications can be configured to create large samples of smaller parts of the full population of data to allow for analysis at very high accuracy levels for smaller populations of visitors, though this is not the default configuration.
[0443] It is important to understand that inaccuracies introduced by other factors into the collection of the entire population of data my any known means make it unclear as to whether inaccuracies introduced by random sampling are not outweighed by others that would be experienced in doing lengthy queries of all of the fact data, or are already existent due to data collection process limitations. Clearly, applications such as Visual Site are not designed to replace a relational database that helps you get detailed information about individual users in your visitor population, support your transactional systems, or replace your accounting system for the tracking or revenue and expenditure. These applications, such as Visual Site, are built to allow you to analyze your customers, campaigns, business process and system performance over time and other dimensions so that you may observe patterns, trends, and changes that help you optimize your profitability and your return on investment. The sampling technology of the present invention allows users to rapidly query the equivalent otherwise unapproachably vast amounts of data in just milliseconds. Other significant factors also contribute to VOLAP's ability to visually explore data so rapidly.
[0444] Incremental sampling is accomplished in the present example embodiment according to the following description. Given:
a sequence of visitor ID values v(i) a desired sample size “size” a hash function “H”, such that 0<=H(v)<1 a function “distinct”, such that distinct(x)=the number of distinct v(i) where i<=x.
[0449] The algorithm:
[0000]
for i in range(1, infinity):
if H(v(i)) < size / distinct(i) and v(i) never in sample:
add v(i) to sample.
[0450] (1) This Produces a Random Sample of v, Assuming there are No Duplicates in v
[0451] After j values have been processed, the probability that item v(i) is in the sample (i<=j) is given by size/distinct(j)=size/j (if v has no duplicates, then clearly distinct(x)=x)
[0452] This is proved by induction on j.
[0453] When j=i, item v(i) was just added to the sample with probability size/j, so it is in the sample with probability size/j by definition.
[0454] If at time j−1 v(i) was in the sample with probability size/(j−1), then at time j: With probability A=1−size/(j−1), v(i) was not in the sample before, and is still not in the sample.
[0455] With probability B=(size/(j−1))*(size/j)*(1/size), v(i) was in the sample before, and was just evicted.
[0456] Otherwise, v(i) is in the sample at time j. This has probability
[0000]
1
-
(
A
+
B
)
=
1
-
(
1
-
size
/
(
j
-
1
)
+
(
size
/
(
j
-
1
)
)
*
(
size
/
j
)
*
(
1
/
size
)
)
)
=
size
/
(
j
-
1
)
-
(
size
/
(
j
-
1
)
)
*
(
size
/
j
)
*
(
1
/
size
)
=
size
/
(
j
-
1
)
-
size
/
(
j
-
1
)
/
j
=
(
j
*
size
-
size
)
/
j
/
(
j
-
1
)
=
size
*
(
(
j
-
1
)
/
j
/
(
j
-
1
)
=
size
/
j
QED
[0457] (2) Duplicates in the v(i) List have No Effect
[0458] Given a v list with duplicates, find the first pair i and j such that v(i)=v(j) and i<j. By removing v(j) from the list, a list v′ is constructed that contains one less duplicate pair. This shows that the algorithm produces the same results on v and on v′; by induction it produces the same results on a list v″ that contains no duplicates.
[0459] Either v(i) is added to the sample or it is not. In either case, it shows that v(j) is not added to the sample, since in v′ v(j) is not present and therefore cannot be added to the sample.
[0460] If v(i) is added to the sample, then by definition “v(i) never in sample” is false, and since v(i)=v(j) “v(j) never in sample” is false. Therefore v(j) is not added to the sample.
[0461] If v(i) is not added to the sample, then H(v(i))<size/distinct(i). Since i<j, distinct(i)<=distinct(j). Therefore:
[0000] H ( v ( i ))= H ( v ( i ))<size/distinct( i )<=size/distinct( j )
[0000] H ( v ( j ))<size/distinct( j )
[0462] and therefore v(j) is not added to the sample.
[0463] (3) For a Sequence of v(i) with No Duplicates:
[0000] distinct( x )= x
[0000] v ( i )never in sample=true
[0464] Optionally, H(v(i))=FRAND( ). Since each v(i) is only seen once, random numbers and hash functions are indistinguishable. Be careful not to use float(rand( ))/RAND_MAX, since RAND_MAX is too low for adequate precision.
[0465] The database is periodically saved as a backup precaution. The time between saves is configurable in the configuration file.
[0466] 3. Transactions
[0467] The sampling process of the Visual Server generates a queue of transactions composed of a transaction for each discrete change that it intends to make. A list of the currently defined transactions is:
[0000]
InsertVisitorTrans
Adds a new visitor to the sample database
InsertReferrerTrans
Adds a new referrer to the referrer dimension
InsertSessionTrans
Adds a new session to a visitor's clickstream in
the database
InsertPageTrans
Adds a new page to the page dimension
InsertClickTrans
Adds a new click to a session
DeleteVisitorTrans
Removes a visitor from the sample (so that it
can be replaced)
UpdateTotalSeenTrans
Special transaction - see VSTP discussion
below.
DatabaseSnapshotTrans
Special transaction - see VSTP discussion
below.
[0468] As a transaction is generated by the processTransaction( ) function, the transaction is placed on the end of a circular transaction log, which then executes the transaction against the server database. The same transactions are requested by all Visual Workstations connected to that visual server once they have been created, this serves to keep the database on the server and the database on each of the clients synchronized.
[0469] The circular transaction log is the log of transactions that are being created by Visual Server for insertion into the database on Visual Server and the databases that are auto-distributed and updated wherever Visual Workstation is installed. The transaction queue is the queue of Web Server transaction information or “log data” that is queued up for secure transit to the Visual Workstation.
[0470] The size of this log is also configurable in the configuration file. The processing server builds up its database by executing these transactions. The transaction log works in conjunction with the Visual Server Transmission Protocol (VSTP) to synch up Visual Workstation databases. The special transaction UpdateTotalSeenTrans is placed in the log periodically to inform the workstation of the total number of visitors seen so far by the sampling process. This transaction is never executed on the server side, only on the workstation. The DatabaseSnapshotTrans is never placed in the log nor executed on the server side. Instead it is generated in special circumstances (see VSTP discussion below) on the server, transmitted to the workstation, and executed there.
[0471] 4. Visual Sciences Transmission Protocol (VSTP) and the Transaction Log
[0472] Visual Workstation connects to port 443 on Visual Server as if the Visual Server was a web server running HTTPS. A connection is maintained and reconstructed if lost. Visual Server uses the connection to push incremental updates from its database to the database on Visual Workstation. Visual Server continues to push these updates incrementally until the databases are synchronized. If a Visual Workstation is disconnected for a period of time and then reconnected to the network, Visual Server will begin sending all updates since the time when Visual Workstation was connected to the Visual Workstation upon reconnection. Data being send to Visual Workstation is represented in a binary format that provides a first level of data security. The connection between Visual Workstation and Visual Server is also encrypted using SSL.
[0473] When an application (e.g., Visual Site) running on a Visual Workstation connects via HTTP/SSL to the processing server, the application transmits a database identifier and a pointer into the transaction log. If it is the first time the application is run, then it sends a pair of zeros. The Visual Server checks that the database identifier to determine if the transmitted database identifier identifies the database on the Visual Server. If the transmitted database identifier does not correspond to the database present on the Visual Server, then the Visual Server treats the situation as if it were the first time the application were run.
[0474] If the transaction log has wrapped, causing the pointer to be invalid, a DatabaseSnapshotTrans transaction is generated, and transmitted back to the application. The application then executes the transaction, giving it a snapshot of the database at the time it was taken and updating the transaction log pointer.
[0475] When a valid transaction pointer is sent to the Visual Sever, the transactions in the transaction log up to that pointer are sent to the application every X milliseconds. The value of X is configurable in the configuration file. As each transaction is executed, it gets closer and closer to matching the database on the server, until it is running in real time, at which point transactions come in as they are generated on the server.
[0476] In certain cases, the whole database is sent to the client again as a single transaction to refresh the client database, this is generally done when something structurally significant is done to change the server database.
[0477] The following are sample contents of an a configuration file (config.vsc):
[0478] SampleSize=200000
[0479] TLogSize=40000000
[0480] BackupDelay=240000
[0481] TransmissionDelay=1000
[0482] SiteList=everbank.com, mids.com
[0483] WorkingDirectory=cd:\Visual Sciences\ETL\Logs
[0484] SequenceMask=−24.168.212.55. log
[0485] SequenceMask=−24.168.212.57. log
[0486] C. Visual Workstation/Applications
[0487] Visual Site is an example application that runs on the Visual Workstation and that is focused on providing business value from the data that can be collected about customers, campaigns, and business processes that exist on the Internet. For large sites the amounts of data can be larger than almost any other set that is routinely collected in the business world, for instance if a site is receiving 100 million visits a day and each visitor makes an average of 10 clicks on URLs in a visit, then 1 billion transactions would be logged each representing approximately 300 Bytes of data each or 300 Gigabytes of data per day or approximately 110 Terabytes (109,500,000,000,000) of data in a year. Because Visual Site as an application is focused in the domain of web transaction data, the above discussed statistical sampling is the only cost-effective way to analyze such vast quantities of data and still present that data to the user in sub-second response times. Today a system does not exist that could process the entire 110 Terabytes of data to analyze one year interactively at sub-millisecond query response times.
[0488] However, many application areas that the VOLAP technology are suitable for may not have enough data to warrant or require random statistical sampling to be used by VOLAP to provide the application and maintain sub-second data access performance.
[0489] VOLAP does not use cubes, aggregations or multi-dimensional arrays in the same way that they are used by “cube or aggregation vendors.” “Cube or aggregation” vendors have relatively longer-term processes that aggregate data into multi-dimensional arrays and then queries are performed against those arrays. VOLAP technology allows very fast access to its database and allows the rapid location of data in that database. The data that VOLAP queries each time is the fact data, not an aggregation of the data into multi-dimensional arrays that needed to be prepared in advance. VOLAP's tremendously fast data access abilities allow it to create multi-dimensional arrays and multiple other types of data structures on-the-fly in milliseconds if they are needed for a particular type of analysis.
[0490] A VOLAP Application implies the following:
[0491] 1. The work has already been done to get data from primary systems that relate to the application (web servers in this case) into a data model for the applications, into the VOLAP technology platform and generally available for application functionality to use in serving information to the user of Visual Workstation;
[0492] 2. Interactive visualizations have been developed to illustrate the dynamics of the data to the user;
[0493] 3. Types of analysis functionality, including inference models, have been added to the Visual Workstation to help the user evaluate their options and optimize their business value; and
[0494] 4. Workspaces and dashboards have been customized that tailor the user interface of the application to the particular needs and tasks of its users.
[0495] D. Visual Site
[0496] Visual Site is designed to allow its users to recognize trends, correlations, and gain insights into the dynamics of their business processes, marketing campaigns, customer relationships and system performance over time. Visual Site uses advanced statistical methods to allow its users to search the vast amounts of data collected by their servers in milliseconds, fast enough to allow for visualizations that represent tens of thousands of data values, in ways that can be easily understood and rendered in real-time when user's select the data that they want to view through Visual Workstation's advanced interactive graphical query building interface.
[0497] Visual Site is best defined as the application that runs on the set of data that includes that collected from Web servers and related applications and databases, but is oriented around Visitor Sessions to such systems. A number of specific visualizations have been defined for Visual Site such as 3D Site Map, which shows visitor traffic across the pages in a web site and shows the conversion, retention or duration metrics across those pages.
[0498] Visual Site supports a number of primary metrics including:
1. Visits—Visitor Sessions; 2. Conversion—The rate at which a user at point X converts to point Y that has business value to a site (such as a purchase); 3. Value—The value of N events completed by the selected customers on a site; 4. Exits—The points at which customers leave the site; 5. Exit Value—The cost of the loss of a customer at a certain point in the site based on what others who had made it to that point created in terms of value in the remainder of their sessions; 6. Duration—The amount of time that a customer session persists; and 7. Retention—The rate at which a customer returns to the site.
[0506] Visual Site supports a number of dimensions
1. Time—Can view metrics over all types of time dimensions: Day, Week, Month, etc.; 2. Referrers—Can view metrics over by referrer; 3. Page—Can view at metrics by page
[0510] Additional applications can be written to run on Visual Workstation. These applications would look at other types of data.
[0511] The systems, processes, and components set forth in the present description may be implemented using one or more general purpose computers, microprocessors, or the like programmed according to the teachings of the present specification, as will be appreciated by those skilled in the relevant art(s). Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the relevant art(s). The present invention thus also includes a computer-based product which may be hosted on a storage medium and include instructions that can be used to program a computer to perform a process in accordance with the present invention. The storage medium can include, but is not limited to, any type of disk including a floppy disk, optical disk, CDROM, magneto-optical disk, ROMs, RAMs, EPROMs, EEPROMs, flash memory, magnetic or optical cards, or any type of media suitable for storing electronic instructions, either locally or remotely.
[0512] The foregoing has described the principles, embodiments, and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments described above, as they should be regarded as being illustrative and not as restrictive. It should be appreciated that variations may be made in those embodiments by those skilled in the art without departing from the scope of the present invention.
[0513] While a preferred embodiment of the present invention has been described above, it should be understood that it has been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by the above described exemplary embodiment.
[0514] Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described herein.
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Systems and methods for processing and reporting information and data, such as business information, and more particularly, to systems, software, hardware, products, and processes for use by businesses, individuals and other organizations to collect, process, distribute, analyze and visualize information, including, but not limited to, business intelligence, data visualization, data warehousing, and data mining. Real-time monitoring of web site interactions allows users to modify and fine-tune their websites to maximize value realized.
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FIELD OF THE INVENTION
This invention is directed generally to stiffeners for epaulets worn on clothing, and more particularly to removable wire stiffeners for uniform epaulets.
BACKGROUND OF THE INVENTION
Shoulder epaulets have been used for many years, particularly to carry insignia on uniforms. It is common practice to employ a stiffening member within an epaulet to make it rigid and thereby prevent buckling and wrinkling of the epaulet which would detract from its appearance. For this purpose, treated cloth or plastic stiffening sheets have been used. However, such stiffeners cause discomfort to the wearer.
In addition, such stiffening elements are usually incorporated directly into the epaulet and either are not removable or are difficult to remove when the garment or the epaulet or loss of stiffening by the stiffening member.
SUMMARY OF THE INVENTION
It is accordingly a principal object of the present invention to provide an improved epaulet stiffener which prevents discomfort to the wearer but which is still effective in maintaining the tautness, and thus the neat appearance of the epaulet during wear.
It is further object of the present invention to provide an improved epaulet stiffener which is readily inserted in and removed from the epaulet.
It is a still further object of the present invention to provide an improved epaulet stiffener which is simple in construction, economical to manufacture, and suitable for different size epaulets.
These and other objects are achieved in accordance with the present invention by an epaulet stiffener comprising a spring wire frame which is insertable inside the epaulet. Resilient legs of the frame urge opposed edges of the epaulet outward and the epaulet assumes a taut condition. The spring wire frame is inserted or removed from the epaulet by urging the resiliently opposed legs of the frame together.
These and other objects, features and advantages of the present invention are described in or apparent from the following detailed description of a preferred embodiment.
DESCRIPTION OF THE DRAWINGS
The preferred embodiment will be described with reference to the drawings, in which:
FIG. 1 is a plan view of a stiffening frame member according to the invention in unrestrained condition;
FIG. 2 illustrates the frame member of FIG. 1 in a compressed condition; and
FIG. 3 is a partial cutaway view of an epaulet showing insertion or removal and positioning of the stiffening frame member within the epaulet.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a stiffening member 10 in the form of a substantially planar wire frame. Stiffening member 10 in FIG. 1 is in an unrestrained condition. Stiffening member 10 may be made of a wide variety of suitable materials, the most effective material being spring steel wire.
The stiffening member 10 includes a transverse base member 12. When stiffening member 10 is not tensioned, the base member has a slightly arcuate shape. A pair of opposed leg members 14a and 14b are joined to opposite ends of the base member 12 and extend angularly therefrom in a flared relationship, as shown, in the untensioned state of stiffening member 10. The free ends of the legs 14a, 14b carry end sections 16a, 16b, respectively, which extend inwardly toward the longitudinal axis of the frame. The ends of the sections 16a, 16b are terminated by bends 18a, 18b, respectively, which are included to minimize snagging or damage to the cloth epaulet. Opposed arcuate depressions 19a, 19b in legs 14a, 14b serve as finger engagement points along the legs.
FIG. 2 shows the condition of the stiffening member 10 when opposed laterally inwardly directed forces f urge the free ends of the legs 14a, 14b toward the longitudinal center line of the frame. Under these conditions, stiffening member 10 has a substantially rectangular frame shape. The base 12 assumes a less arcuate shape and serves to resiliently bias the legs 14a, 14b outwardly.
Referring to FIG. 3, an epaulet 20 is shown having a hollow body 22 into the interior of which stiffening member 10 is inserted. The upper surface of the body 22 can carry suitable ornamentations such as military insignia (not shown). Epaulet 20 is made of suitable material, usually a piece of cloth which has been sewn with a longitudinal seam to form body 22.
In order to stiffen the epaulet body 22, stiffening member 10 is placed in the condition shown in FIG. 2 by engaging stiffening member 10 at depression 19a, 19b and moving the leg members 14a, 14b together. In this condition, the stiffening member is slipped inside the epaulet body 22. When the stiffening member is released, the spring bias imparted by the base member 12 urges the legs 14a, 14b outwardly against inside edges 24a, 24b of the epaulet body. Stiffening member 10 is sized relative to the body 22 so that when it is inside the epaulet body, it is restrained from achieving the unconfined shape shown in FIG. 1, thus forming a frame which maintains a constant tension within the body 22. Epaulet 20 is thus maintained in a taut condition. Removal of the frame 22 is accomplished by reversing the insertion steps.
Preferably, stiffening member 10 is somewhat shorter longitudinally than the epaulet body 22, so that the ends of the stiffening member are hidden within epaulet 20.
The construction just described results in a lightweight epaulet stiffener having a substantially open central area which is capable of conforming to the shoulder surfaces of the wearer, thereby making the epaulet more comfortable to wear. Further, the stiffener is easily and quickly removable, and is very economical to manufacture.
It will be appreciated that the disclosed preferred embodiment is merely illustrative of the present invention, and that changes and modifications can be made without departing from the spirit and scope of the invention.
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A removable and economical stiffener comprises a spring wire frame having a base member which resiliently biases two depending side members so as to maintain an epaulet in a relatively taut, planar condition.
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[0001] This application claims benefit, under U.S.C. §119(a) of French National Application Number 03.09640, filed Aug. 5, 2003; and also claims benefit, under U.S.C. §119(e) of U.S. provisional application 60/523,216, filed Nov. 19, 2003.
FIELD OF THE INVENTION
[0002] The present invention relates to a multilayer structure that includes an impact-modified EVOH layer. The structure may comprise the following successive layers:
a polyamide or HDPE (high-density polyethylene) layer; a tie layer; the impact-modified EVOH layer; optionally, a tie layer; and a polyamide or polyamide/polyolefin blend or polyolefin layer.
[0008] The latter polyamide or polyamide/polyolefin blend or polyolefin layer may contain fillers in order to make it antistatic.
[0009] These structures, in which the polyamide or HDPE layer is the outer layer and the polyamide or polyamide/polyolefin blend or polyolefin layer is the inner layer in contact with the fluid (petrol), are useful for making tanks, containers, bottles and tubes. They may be manufactured by coextrusion or by coextrusion blow moulding. The benefit of these structures is that they act as a barrier to many substances. One particularly beneficial use relates to tubes for transporting petrol and in particular for transporting petrol from the tank of a motor vehicle right to the engine. Another particularly beneficial use relates to petrol tanks for motor vehicles.
BACKGROUND OF THE INVENTION
[0010] For safety and environmental protection reasons, motor vehicle manufacturers require tubes for transporting petrol to have both good mechanical properties, such as burst strength and flexibility, with good cold (−40° C.) and high-temperature (125° C.) impact strength, and also very low permeability to hydrocarbons and to their additives, particularly alcohols such as methanol and ethanol. These tubes must also have good resistance to the fuels and lubrication oils for the engine. These tubes are manufactured by coextruding the various layers using standard techniques for thermoplastics.
[0011] Among the characteristics of the specification for these tubes, five are particularly difficult to obtain jointly in a simple manner:
cold (−40° C.) impact strength—the tube must not break; fuel resistance; high-temperature (125° C.) strength; very low permeability to petrol; and good dimensional stability of the tube when used with petrol.
[0017] In multilayer tubes of various structures, the cold impact strength remains unpredictable before the standardized tests for cold impact strength have been carried out.
[0018] It has been discovered that, in a structure comprising the following successive layers:
a polyamide or HDPE (high-density polyethylene) layer; a tie layer; an EVOH layer; optionally, a tie layer; and a polyamide or polyamide/polyolefin blend or polyolefin layer,
subjected to impacts or to other equivalent mechanical stresses, cracks are initiated in the EVOH layer and propagate into the entire structure.
[0025] It has also been discovered that, if the EVOH layer is modified by adding a sufficient amount of an impact modifier to it, then, in the event of an impact, cracks can still be initiated in this layer but there is no longer enough energy to propagate the crack or cracks into the other layers, and therefore the structure is impact-resistant.
[0026] Patent EP 1122 061 has disclosed a structure comprising, in succession:
a high-density polyethylene (HDPE) first layer; a tie layer; an EVOH, or EVOH-based blend, second layer; and optionally, a polyamide (A), or polyamide (A)/polyolefin (B) blend, third layer.
[0031] Three EVOH-based blends are described in that patent. The first blend relates to compositions comprising (by weight):
55 to 99.5 parts of EVOH copolymer; and 0.5 to 45 parts of polypropylene and compatibilizer, their proportions being such that the ratio of the amount of polypropylene to the amount of compatibilizer is between 1 and 5.
[0034] The second blend relates to compositions comprising:
50 to 98% by weight of an EVOH copolymer; 1 to 50% by weight of a polyethylene; and 1 to 15% by weight of a compatibilizer formed from a blend of an LLDPE or metallocene polyethylene and of a polymer chosen from elastomers, very low-density polyethylenes and metallocene polyethylenes, the blend being cografted by an unsaturated carboxylic acid or a functional derivative of this acid.
[0038] The third blend relates to compositions comprising:
50 to 98% by weight of an EVOH copolymer; 1 to 50% by weight of an ethylene/alkyl (meth)acrylate copolymer; and 1 to 15% by weight of a compatibilizer resulting from the reaction of (i) a copolymer of ethylene and of an unsaturated monomer X grafted or copolymerized with (ii) a copolyamide.
[0042] Patents EP 1 243 831. EP 1 314 758, EP 1 314 759 and EP 1 331 091 disclose multilayer pipes which include an EVOH layer that can be formed from an EVOH-based blend identical to the blends disclosed in the abovementioned patent EP 1 122 061. These EVOH-based blends are insufficient for high impacts.
BRIEF DESCRIPTION OF THE INVENTION
[0043] The present invention relates to a multilayer structure comprising the following successive layers:
a polyamide or HDPE (high-density polyethylene) layer; a tie layer; an impact-modified EVOH layer; optionally, a tie layer; and a polyamide or polyamide/polyolefin blend or polyolefin layer, the latter layer possibly containing fillers in order to make it antistatic;
and such that the impact-modified EVOH layer is a blend based on EVOH and at least one impact modifier chosen from:
a) functionalized ethylene/alkyl (meth)acrylate copolymers; b) products resulting from the reaction of (i) a copolymer of ethylene and of an unsaturated monomer X grafted or copolymerized with (ii) a polyamide; c) blends of a) and b); d) polyamides, preferably PA-6; e) blends of a) and d); f) elastomers, preferably EPR, EPDM and NBR, these elastomers possibly being functionalized; g) S-B-M triblocks; h) triblocks formed from a poly(butyl acrylate) block between two PMMA blocks; and i) linear or star S-B-S block copolymers, these optionally being hydrogenated (they are then denoted by S-EB-S).
[0059] Advantageously, the proportion of impact modifier is, by weight, between 1 and 35% per 75 to 99% of EVOH respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0060] As regards a), the functional groups may be an acid, an acid anhydride or an unsaturated epoxide. The amount of unsaturated carboxylic anhydride may be up to 15% by weight of the copolymer and the amount of ethylene may be at least 50% by weight.
[0061] For example, this is a copolymer of ethylene, an alkyl (meth)acrylate and an unsaturated carboxylic anhydride. Preferably, the alkyl (meth)acrylate is such that the alkyl possesses 2 to 10 carbon atoms. The alkyl (meth)acrylate may be chosen from methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate and 2-ethylhexyl acrylate. The MFI may, for example, be between 0.1 and 50 (g/10 min at 190° C./2.16 kg).
[0062] For example, it is a copolymer of ethylene, an alkyl (meth)acrylate and an unsaturated epoxide. Preferably, the alkyl (meth)acrylate is such that the alkyl possesses 2 to 10 carbon atoms. The MFI (melt flow index) of (A) may, for example, be between 0.1 and 50 (g/10 min at 190° C./2.16 kg). Examples of alkyl acrylate or methacrylate that can be used are, in particular, methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate and 2-ethylhexyl acrylate. Examples of unsaturated epoxides that can be used are, in particular:
aliphatic glycidyl esters and ethers, such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and glycidyl itaconate, glycidyl acrylate and glycidyl methacrylate; and alicyclic glycidyl esters and ethers, such as 2-cyclohexen-1-yl glycidyl ether, diglycidyl cyclohexene-4-5-carboxylate, glycidyl cyclohexene-4-carboxylate, glycidyl 2-methyl-5-norbornene-2-carboxylate and diglycidyl endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate.
[0065] As regards b), this is, for example a polyamide-block graft copolymer formed from a polyolefin backbone and at least one polyamide graft, in which:
the grafts are attached to the backbone via the residues of an unsaturated monomer (X) having a functional group capable of reacting with an amine-terminated polyamide; and the residues of the unsatured monomer (X) are attached to the backbone by grafting or copolymerization from its double bond.
[0068] As regards the polyamide-block graft copolymer, this may be obtained by the reaction of an amine-terminated polyamide with the residues of an unsaturated monomer X attached by grafting or copolymerization to a polyolefin backbone.
[0069] This monomer X may, for example, be an unsaturated epoxide or an unsaturated carboxylic acid anhydride. The unsaturated carboxylic acid anhydride may be chosen, for example, from maleic, itaconic, citraconic, allylsuccinic, cyclohex-4-ene-1,2-dicarboxylic, 4-methylenecyclohex-4-ene-1,2-dicarboxylic, bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic and x-methylbicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydrides. Advantageously, maleic anhydride is used. It would not be outside the scope of the invention to replace all or part of the anhydride with an unsaturated carboxylic acid, such as for example acrylic acid or methacrylic acid. Examples of unsaturated epoxides were mentioned above.
[0070] As regards the polyolefin backbone, a polyolefin is defined as being a homopolymer or copolymer of alpha-olefins or diolefins, such as for example ethylene, propylene, 1-butene, 1-octene and butadiene.
[0071] As regards ethylene/X copolymers, that is to say those in which X is not grafted, they are copolymers of ethylene, X and optionally another monomer.
[0072] Advantageously, ethylene/maleic anhydride and ethylene/alkyl (meth)acrylate/maleic anhydride copolymers are used. These copolymers comprise from 0.2 to 10% by weight of maleic anhydride and from 0 to 40%, preferably 5 to 40%, by weight of alkyl (meth)acrylate. Their MFIs are between 5 and 100 (190° C./2.16 kg). The alkyl (meth)acrylates have already been mentioned above. The melting point is between 60 and 100° C.
[0073] With regard to the amine-terminated polyamide, the term “polyamide” is understood to mean the products resulting from the condensation:
of one or more amino acids, such as aminocaproic, 7-aminoheptanoic, 11-ainoundecanoic and 12-aminododecanoic acids or of one or more lactams, such as caprolactam, oenantholactam and lauryllactam; of one or more salts or mixtures of diamines such as hexamethylenediamine, dodecamethylenediamine, metaxylylenediamine, bis(p-aminocyclohexyl)methane and trimethylhexamethylenediamine with diacids such as isophthalic, terephthalic, adipic, azeleic, suberic, sebacic and dodecanedicarboxylic acids; or of mixtures of several monomers, resulting in copolyamides.
[0077] Polyamide or copolyamide blends may be used. Advantageously, PA-6, PA-11, PA-12, the copolyamide having 6 units and 11 units (PA-6/11), the copolyamide having 6 units and 12 units (PA-6/12) and the copolyamide based on caprolactam, hexamethylenediamine and adipic acid (PA-6/6,6) are used. The advantage of copolyamides is that it is thus possible to choose the melting point of the grafts.
[0078] Advantageously, the grafts are homopolymers consisting of residues of caprolactam, 1-amino-undecanoic acid or dodecalactam, or copolyamides consisting of residues chosen from at least two of the three above monomers.
[0079] The degree of polymerization may vary widely; depending on its value, this is a polyamide or a polyamide oligomer. In the rest of the text, the two expressions for the grafts will be used without distinction.
[0080] In order for the polyamide to have a monoamine terminal group, all that is required is to use a chain stopper of formula:
in which:
R 1 is hydrogen or a linear or branched alkyl group containing up to 20 carbon atoms; R 2 is a linear or branched, alkyl or alkenyl, group having up to 20 carbon atoms, a saturated or unsaturated cycloaliphatic radical, an aromatic radical or a combination of the above. The chain stopper may, for example, be laurylamine or oleylamine.
[0084] Advantageously, the amine-terminated polyamide has a molar mass of between 1 000 and 5 000 g/inol and preferably between 2 000 and 4 000 g/mol.
[0085] The preferred amino acid or lactam monomers for synthesizing the monoaminated oligomer according to the invention are chosen from caprolactam, 11-amino-undecanoic acid or dodecalactam. The preferred monofunctional polymerization stoppers are laurylamine and oleylamine.
[0086] The polycondensation defined above is carried out using standard known processes, for example at a temperature generally between 200 and 300° C., in a vacuum or in an inert atmosphere, with stirring of the reaction mixture. The average chain length of the oligomer is determined by the initial molar ratio of the polycondensable monomer or the lactam to the monofunctional polymerization stopper. To calculate the mean chain length, it is usual practice to count one chain limiter molecule per oligomer chain.
[0087] The addition of the monoaminated polyamide oligomer to the polyolefin backbone containing X is effected by an amine functional group of the oligomer reacting with X. Advantageously, X carries an anhydride or acid functional group; amide or imide links are thus created.
[0088] The amine-terminated oligomer is added to the polyolefin backbone containing X preferably in the melt state. Thus, it is possible, in an extruder, to mix the oligomer with the backbone at a temperature generally between 230° and 250° C. The mean residence time of the melt in the extruder may be between 15 seconds and 5 minutes, preferably between 1 and 3 minutes. The efficiency of this addition is evaluated by selective extraction of the free polyamide oligomers, that is to say those that have not reacted to form the final graft copolymer having polyamide blocks.
[0089] The preparation of such amine-terminated polyamides and their addition to a polyolefin backbone containing X is described in U.S. Pat. No. 3,976,720, U.S. Pat. No. 3,963,799, U.S. Pat. No. 5,342,886 and FR 2291225.
[0090] As regards the triblocks g), mention may be made of S-B-M triblocks in which:
each block is linked to another by means of a covalent bond or an intermediate molecule linked to one of the blocks via a covalent bond and to the other block via another covalent bond; the block M is formed from MMA monomers that are optionally copolymerized with other monomers and comprises at least 50% methyl methacrylate (MMA) by weight; the block B is incompatible with the EVOH and with the block M; and the block S is incompatible with the block B and the block M, and its T g or its melting point T m , is above the T g of B.
[0095] As regards the S-B-M triblock, M is formed from methyl methacrylate monomers or contains at least 50 wt % methyl methacrylate, preferably at least 75 wt % methyl methacrylate. The other monomers making up the block M may or may not be acrylic monomers and may or may not be reactive. As non-limiting examples of reactive functional groups mention may be made of the following: oxirane functional groups, amine functional groups and carboxyl functional groups. The reactive monomer may be (meth)acrylic acid or any other hydrolysable monomer leading to these acids.
[0096] Among the other monomers that can form the block M, mention may be made, by way of non-limiting example, of glycidyl methacrylate and tert-butyl methacrylate. Advantageously, M is formed from at least 60% syndiotactic PMMA.
[0097] Advantageously, the T g of B is below 0° C. and preferably below −40° C.
[0098] The monomer used to synthesize the elastomeric block B may be a diene selected from butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and 2-phenyl-1,3-butadiene. Advantageously, B is selected from poly(dienes), especially poly(butadiene), poly(isoprene) and random copolymers thereof, or else from partially or completely hydrogenated poly(dienes). Among polybutadienes, it is advantageous to use those whose T g is the lowest, for example 1,4-polybutadiene having a T g (about ° C.) below that of 1,2-polybutadiene (about 0° C.). The blocks B may also be hydrogenated. This hydrogenation is carried out using standard techniques.
[0099] The monomer used to synthesize the elastomeric block B may also be an alkyl (meth)acrylate; the following T g s, given in brackets, which follow the name of the (meth)acrylate are obtained: ethyl acrylate (−24° C.), butyl acrylate (−54° C.), 2-ethylhexyl acrylate (−85° C.), hydroxyethyl acrylate (−15° C.) and 2-ethyhexyl methacrylate (−10° C.). It is advantageous to use butyl acrylate. The acrylates are different from those of the block M in order to meet the condition of B and M being incompatible.
[0100] Preferably, the blocks B are formed mostly from 1,4-polybutadiene.
[0101] The T g or T m of S is advantageously above 23° C. and preferably above 50° C. As examples of blocks S, mention may be made of those that derive from vinyl aromatic compounds such as, for example, styrene, α-methylstyrene and vinyltoluene.
[0102] Advantageously, the S-B-M triblock is a polystyrene/polybutadiene/PMMA triblock.
[0103] The S-B-M triblock has a number-average molar mass that may be between 10 000 g/mol and 500 000 g/mol, preferably between 20 000 and 200 000 g/mol. The S-B-M triblock advantageously has the following composition, expressed as fractions by weight, the total being 100%:
M: between 10 and 80% and preferably between 15 and 70%; B: between 2 and 80% and preferably between 5 and 70%; S: between 10 and 88% and preferably between 15 and 85%.
[0107] The S-B-M triblocks may be blended with S-B diblocks. As regards the S-B diblock, the blocks S and B have the same properties as the blocks S and B of the S-B-M triblock, they are incompatible and they are formed from the same monomers and optionally comonomers as the blocks S and the blocks B of the S-B-M triblock. That is to say, the blocks S of the S-B diblock are formed from monomers selected from the same family as the family of monomers available for the blocks S of the S-B-M triblock. Likewise, the blocks B of the S-B diblock are formed from monomers selected from the same family as the family of monomers available for the blocks B of the S-B-M triblock.
[0108] The S-B diblock has a number-average molar mass that may be between 10 000 g/mol and 500 000 g/mol, preferably between 20 000 and 200 000 g/mol. Advantageously, the S-B diblock is formed from a mass fraction of B of between 5 and 95% and preferably between 15 and 85%.
[0109] The blend of S-B-M triblock and S-B diblock advantageously comprises between 5 and 80% S-B diblock per 95 to 20% S-B-M triblock, respectively.
[0110] In addition, the advantage of these compositions is that it is unnecessary to purify the S-B-M after it has been synthesized. This is because S-B-M triblocks are generally prepared from S-B diblocks and the reaction often results in an S-B/S-B-M blend that is then separated in order to have the S-B-M triblock.
[0111] These S-B-M triblock copolymers may be manufactured by anionic polymerization, for example using the processes described in Patent Applications EP 524 054 and EP 749 987. They may also be manufactured by controlled radical polymerization. These S-B-M triblock copolymers are described in Patent WO 29772.
[heading-0112] As Regards i)
[0113] S-B-S triblocks are described in Ullman's Encyclopedia of Industrial Chemistry, Volume A 26, pages 655-659.
[0114] As examples of S-B-S triblocks, mention may be made of linear triblocks in which each block is linked to another by means of a covalent bond or an intermediate molecule linked to one of the blocks via a covalent bond and to the other block via another covalent bond. The blocks S and B have the same properties as the blocks S and B of the S-B-M triblock, they are incompatible and they are formed from the same monomers and optionally comonomers as the blocks S and the blocks B of the S-B-M triblock. That is to say the blocks S of the S-B-S triblock are formed from monomers selected from the same family as the family of monomers available for the blocks S of the S-B-M triblock. Likewise, the blocks B of the S-B-S triblock are formed from monomers selected from the same family as the family of monomers available for the blocks B of the S-B-M triblock. The blocks S and B may be identical to or different from the other blocks S and B present in the other block copolymers.
[0115] The linear S-B-S triblock has a number-average molar mass that may be between 10 000 g/mol and 500 000 g/mol, preferably between 20 000 and 200 000 g/mol. The S-B-S triblock is advantageously formed from a mass fraction of B of between 5 and 95% and preferably between 15 and 85%.
[0116] As an other example of S-B-S triblocks, mention may be made of star triblocks. The term “triblock” does not accord with the number of blocks, but the term “S-B-S star triblock” is clear to those skilled in the art. As examples of star triblocks, mention may be made of those of formula:
in which n is equal to 1, 2 or 3 and S 1 and B 1 represent blocks. The blocks SI represent polymerized styrene and the blocks B 1 polymerized butadiene, polymerized isoprene or a blend of polymerized butadiene and polymerized isoprene. The blocks B 1 may be hydrogenated (the triblocks are then, for example, S-EB-S triblocks).
[0118] Y is a polyfunctional entity coming, for example, from polyfunctional coupling agents that are used in the manufacture of star block copolymers. Such agents and these block copolymers are described in U.S. Pat. No. 3,639,521.
[0119] Preferred star block copolymers contain 15 to 45% by weight and better still 25 to 35% styrene units. The molar mass is at least 140 000 and better still at least 160 000.
[0120] Particularly preferred star block polymers are those described in EP 451 920. These copolymers are based on styrene and isoprene, the molar mass of the polystyrene blocks is at least 12 000 and the polystyrene content is at most 35% (by weight) of the total mass of the block copolymer.
[0121] The preferred linear block copolymers have a molar mass between 70 000 and 145 000 and contain 12 to 35% polystyrene by weight. Particularly preferred linear block copolymers are those based on styrene and isoprene that are described in European Patent EP 451 919. These copolymers have polystyrene blocks of molar mass between 14 000 and 16 000 and a polystyrene content of between 25 and 35% by weight of the block copolymer. The molar mass is between 80 000 and 145 000 and better still between 100 000 and 145 000.
[0122] It is also possible to use a blend of linear S-B-S triblocks and star S-B-S triblocks.
[0123] These linear or star S-B-S triblocks are commercially available under the brand names FINAPRENE®, FINACLEAR®, KRATON® and STYROLUX®.
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The present invention relates to a multilayer structure comprising the following successive layers: a polyamide or HDPE (high-density polyethylene) layer; a tie layer; an impact-modified EVOH layer; optionally, a tie layer; and a polyamide or polyamide/polyolefin blend or polyolefin layer, the latter layer possibly containing fillers in order to make it antistatic; and such that the impact-modified EVOH layer is a blend based on EVOH and at least one modifier chosen from: a) functionalized ethylene/alkyl (meth)acrylate copolymers; b) products resulting from the reaction of (i) a copolymer of ethylene and of an unsaturated monomer X grafted or copolymerized with (ii) a polyamide; c) blends of a) and b); d) polyamides, preferably PA-6; e) blends of a) and d); f) elastomers, preferably EPR, EPDM and NBR, these elastomers possibly being functionalized; g) S-B-M triblocks; h) triblocks formed from a poly(butyl acrylate) block between two PMMA blocks; and i) linear or star S-B-S block copolymers, these optionally being hydrogenated (they are then denoted by S-EB-S).
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RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/786,793 filed Mar. 28, 2006, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The invention herein described relates generally to a vehicle drive system that provides hydraulic energy storage and more particularly to such a system including auxiliary hydraulic circuits and components that can be powered by the vehicle's prime mover (e.g. engine) or by pressurized hydraulic fluid from the hydraulic energy storage. The power delivery system can be used on a variety of vehicle types, including in particular garbage collection vehicles and other vehicles that make frequent starts and stops and which have auxiliary hydraulic circuits.
BACKGROUND OF THE INVENTION
For many years there has been recognition that vehicles could be made more fuel-efficient if the energy normally lost in decelerating or braking the vehicle could be somehow collected, stored and reused to accelerate the vehicle. A relatively large number of prior patents and published patent applications exist which are directed to various aspects of this general approach. Some have proposed to collect and store the energy in hydraulic accumulators and then reuse the energy through fixed or variable displacement hydraulic transmissions. The recovered energy was used to assist or provide vehicle motion.
Some vehicles, such as refuse trucks, had auxiliary hydraulic circuits that were powered by the vehicle's engine through a power take-off unit. Consequently, it was necessary for the engine to be running to operate the auxiliary hydraulic systems on the truck. Typical auxiliary hydraulic circuits included those use to actuate cylinders, power hydraulic motors (other than those associated with vehicle propulsion), etc.
SUMMARY OF THE INVENTION
The present invention enables the use of stored hydraulic energy to power one or more auxiliary (other than vehicle propulsion) hydraulic systems of a vehicle, thereby eliminating the need to keep an internal combustion engine running. In a preferred embodiment, an auxiliary hydraulic pump (also herein referred to as a body hydraulic pump) has a drive shaft that is coupled to a power take-off unit driven by a prime mover, such as an internal combustion engine, and to an auxiliary hydraulic motor powered by hydraulic fluid supplied from a hydraulic energy storage device such as an accumulator. As a result, the auxiliary hydraulic pump can be powered by hydraulic fluid from the accumulator when the prime mover is not operating, or by the prime mover when operating. A tandem arrangement of one way clutches can be employed to avoid the need to disconnect the auxiliary hydraulic pump from the prime mover during operation of the auxiliary hydraulic motor, and vice versa. In particular, a pair of sprag (one-way) clutches can be used such that the auxiliary hydraulic pump will be driven by the output shaft of the power take off or hydraulic motor that is being driven faster.
More particularly, the invention provides a power transfer system for a vehicle that comprises a prime mover, one or more drive wheels, and a power transfer apparatus that transfers power from the prime mover to the wheels for propelling the vehicle. The power transfer apparatus includes a power input shaft connected to the prime mover, a primary hydraulic pump, a hydraulic drive motor, a pump coupling for coupling the primary hydraulic pump to the power input shaft, a motor coupling for coupling the hydraulic drive motor to an output drive shaft for driving the one or more drive wheels, an energy storage device in which energy can be stored, primary hydraulic pump power circuitry for supplying pressurized hydraulic fluid from the primary hydraulic pump to the energy storage device, and hydraulic motor power circuitry for transferring pressurized hydraulic fluid from the energy storage device to the hydraulic drive motor. The system also comprises an auxiliary hydraulic pump for supplying hydraulic fluid to an auxiliary hydraulic system of the vehicle other than one that effects vehicle propulsion, a power take-off device driven by the power input shaft and drivingly connected to a drive shaft of the auxiliary hydraulic pump, and an auxiliary hydraulic motor powered by pressurized hydraulic fluid from the energy storage device and drivingly connected to the drive shaft of the auxiliary hydraulic pump for driving the drive shaft of the auxiliary hydraulic pump when not driven by the power take-off device.
The hydraulic drive motor may be reversely operable as a hydraulic pump when driven by the output drive shaft for braking of the vehicle and to effect energy recovery, and the hydraulic drive motor power circuitry may be operable to transfer pressurized hydraulic fluid from the hydraulic drive motor/pump to the energy storage device when the hydraulic motor/pump is reversely driven during braking,
In a preferred embodiment, the power take-off device is coupled to the auxiliary hydraulic pump by a one way clutch, and the auxiliary hydraulic motor is coupled to the auxiliary hydraulic pump by a one way clutch, such that the auxiliary hydraulic pump will be driven by the power take-off device or the auxiliary hydraulic motor that is being driven faster.
As will be appreciated by those skilled in the art, one or more of the principles of the present invention can be applied to any hydraulic drive system employing one or more variable displacement drive motors with or without the feature of hydraulic energy recovery.
Further features of the invention will become apparent from the following detailed description when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of an exemplary vehicle drive system including a power drive unit according to the invention.
DETAILED DESCRIPTION
Referring now in detail to the drawings and initially to FIG. 1 , an exemplary vehicle drive system according to the present invention is indicated generally by reference numeral 20 . The vehicle drive system 20 includes a power drive unit 21 connected between a prime mover 22 and the drive wheel or wheels 23 of a vehicle generally denoted by reference numeral 24 . The prime mover preferably is an internal combustion (IC) engine, but other prime movers could also be used, such as gas turbines, electric motors and fuel cells. The power drive unit includes a power input shaft 26 to which the engine is drivingly connected by any suitable means and an output drive shaft 27 drivingly connected to one or more the wheels 23 of the vehicle by any suitable means, such as by a drive shaft 29 and transaxle 30 .
The power drive unit 21 is characterized by a housing 33 that provides a mount for one or more primary hydraulic pumps 34 and one or more hydraulic drive motors 35 (two being shown). The embodiment shown in FIG. 1 utilizes one reversible pump/motor unit 34 and two reversible motor/pump units 35 to drive the vehicle in a city or working mode. This arrangement optimizes the packaging of these units into the unitized transmission by using lower cost standard hydraulic units. It also permits more economical gearing from the dual power paths (lower tooth loading), more responsive shift times (less mechanical inertia), a smaller overall package size and weight, and generally smoother operation.
Each pump 34 and motor 35 may be a variable displacement type, and each preferably can be reversely driven to function as a motor or pump, respectively. By way of example, the pumps and motors may be axial piston pumps and motors, wherein displacement of the pump/motor is varied by changing the tilt angle of a tiltable swash plate, in a manner that is well known to those skilled in the art.
The housing contains a transmission assembly 37 to which the power input shaft 26 and output drive shaft 27 are connected. The housing further provides a mount for one or more auxiliary pumps 39 for cooling, lubrication, and/or low pressure systems along with a mounting position for a power take-off (PTO) device 40 that may be used to provide hydraulic power to other parts of the vehicle. The auxiliary pumps may be a stacked arrangement of pumps, particularly positive displacement pumps, driven by a common drive shaft. As depicted in FIG. 1 , one auxiliary pump may circulate hydraulic fluid through a cooler 42 and back to a reservoir 43 . Another auxiliary pump may be used to supply pressurized fluid to the transmission assembly 37 and/or other drive components for lubrication, and another auxiliary pump may be used to supply low pressure fluid to components of the hereinafter described hydraulic circuits to operate, for example, pilot valves used to control fluid pressure components.
As illustrated in FIG. 1 , the primary pump 34 is mounted to one axial end of the housing while the hydraulic motors 35 are mounted to the opposite axial end of the housing. In addition, the auxiliary pumps 39 are mounted to the same axial side of the housing as the primary pump 34 . The motors and/or pumps may be otherwise mounted. For example, the primary pump could be separately mounted, such as to the engine.
The vehicle drive system 20 further comprises an energy storage device 46 . In the illustrated embodiment the energy storage device is an accumulator system including one or more pressurized fluid accumulators 47 , specifically hydropneumatic accumulators. Other energy storage devices may be used such as a mechanical fly wheel or batteries. The accumulators 47 are supplied with pressurized fluid from the primary pump 34 and/or motors 35 by means of a high pressure manifold and fluid circuitry generally indicated at 50 . The fluid circuitry 50 is commanded by a system controller 52 , more particularly an electronic system controller, to control the flow of pressurized fluid to and from the accumulators 47 , the pump 34 , motors 35 and other hydraulic components, including a flow restrictor 55 , the function of which is discussed below. The system controller may include one or more microprocessors and associated components programmed to carry out the herein described operations. The controller may have various inputs for receiving data from various sensors that monitor various operational parameters of the vehicle and various outputs by which the controller commands various operations.
In a first mode of operation, the position of the vehicle's accelerator and brake pedals may be detected by sensors and act as input commands to the electronic system controller 52 . If the desired action is to accelerate, say from a stop position, the electronic system controller 52 can shift the transmission assembly 37 into a hydro low configuration to start the vehicle in motion. The controller may command the high pressure manifold and hydraulic circuitry 50 to supply high pressure fluid from the accumulator system 46 and/or the primary pump 34 (if then operating) to the hydraulic drive motors 35 to drive the output drive shaft 27 through the transmission assembly 58 . This in turn will drive the drive wheels 23 of the vehicle to accelerate the vehicle from the stopped position. The displacement of the drive motors may be varied by the controller 52 to control the rate of acceleration to increase or maintain a constant speed (zero acceleration). The drive motors can operate to deliver high torque to the drive wheels of the vehicle.
If the vehicle is already moving and a desired action is to decelerate or brake the vehicle, the electronic system controller 52 directs the high pressure manifold and fluid circuitry 50 to receive high pressure fluid from the drive motors 35 which then will be reversely driven and act as pumps, thereby delivering high pressure fluid back to the accumulator system 46 . The hydraulic drive motors, acting as pumps, will generate resistance in the drive train to slow the vehicle down. This action also recovers most of the kinetic energy from the vehicle and stores it in the accumulator system for future use by the drive system or for performing other hydraulically powered work related tasks on the vehicle.
The vehicle may be provided with mechanical brakes that normally will not be needed to decelerate the vehicle, but which will be available for use if the braking force required (such as a panic stop) is greater than that which is being generated by the reversely driven hydraulic motors acting as pumps, or as a back-up in case of a failure in the hydraulic drive system.
Once the vehicle has accelerated to or past an upper end of the hydro low range, such as about 25 mph, the electronic system controller 52 commands the transmission assembly 37 to shift to a hydro high gear ratio.
The transmission assembly 37 as thus far described corresponds to the transmission assembly described in U.S. patent application Ser. No. 11/379,883, which is hereby incorporated herein by reference. Reference may be had to said patent application for further details of the transmission assembly and its manner of operation for propelling and stopping a vehicle. For instance, a transmission assembly or more particularly a pump coupling may include a clutch 37 A for selectively drivingly connecting the primary hydraulic pump 34 to the power input shaft 26 , and the transmission assembly may include a clutch 37 B for selectively drivingly connecting the output drive shaft 27 to the power input shaft 26 .
As above indicated, the power take-off (PTO) device 40 is used to provide hydraulic power to other parts of the vehicle such as hydraulic actuators, motors, etc. that are typically operated when the vehicle is stationary or at least independently of the vehicle components involved in the driving of the vehicle from one location to another. In the case of a refuse truck, the power take-off can be used to supply power to the hydraulic cylinders used to compress the refuse in the refuse collection chamber.
In accordance with the invention, one or more hydraulic body circuits 60 may be provided for powering hydraulic components and systems other than those associated with propulsion of the vehicle and typically those that are operated when the vehicle is stationary. Each hydraulic body circuit 60 includes an auxiliary hydraulic pump 62 (also herein referred to as a body hydraulic pump) that has a drive shaft 63 coupled to the power take-off device 40 that is driven by the engine 22 , and to an auxiliary hydraulic motor 65 powered by hydraulic fluid supplied from the energy storage device 46 . As a result, the auxiliary hydraulic pump can be powered by hydraulic fluid from the accumulators 47 when the engine is not operating, or by the engine via the power take-off device when the engine is running.
In the illustrated preferred embodiment, the PTO device 40 is coupled by a sprag (one-way) clutch 68 to the auxiliary pump drive shaft 63 . The auxiliary hydraulic motor 65 likewise is coupled to the drive shaft of the pump by a sprag (one-way) clutch 70 . If the PTO device and auxiliary hydraulic motor are both being driven, the auxiliary hydraulic pump will be driven by the PTO device or auxiliary hydraulic motor that is being driven faster. In most instances, however, only one of the PTO device and auxiliary hydraulic motor will be driven (under the control of the controller 52 ), in which case the other will be idle and the associated one-way clutch will free-wheel.
While other arrangements are contemplated, in the illustrated embodiment the PTO device 40 is drivingly connected to the input shaft 26 through the transmission assembly 37 which may include one or more clutches for disengaging the PTO output shaft from the engine, such as when the engine is not running. As will be appreciated, though, the PTO device can remain drivingly connected to the engine even when the engine is not running.
Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that 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 elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
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A power transfer system for a vehicle that comprises a an internal combustion engine, one or more drive wheels, and power transfer apparatus transfers power from the prime mover to the wheels for propelling the vehicle. The system further comprises an auxiliary hydraulic pump that has a drive shaft that coupled to a power take-off unit driven by engine, and to an auxiliary hydraulic motor powered by hydraulic fluid supplied from a hydraulic energy storage device such as an accumulator. As a result, the auxiliary hydraulic pump can be powered by hydraulic fluid from the accumulator when the prime mover is not operating, or by the prime mover when operating. A tandem arrangement of one way clutches can be employed to avoid the need to disconnect the auxiliary hydraulic pump from the prime mover during operation of the auxiliary hydraulic motor, and vice versa.
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RELATED APPLICATION
[0001] This application claims benefit of U.S. provisional patent application No. 60/571,442, filed May 14, 2004.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with United States government support pursuant to Gran No. GMS-0301827 from the National Science Foundation. The United States has certain rights to this invention.
COPYRIGHT NOTICE
[0003] ©2005 Electro Scientific Industries, Inc. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR § 1.71(d).
TECHNICAL FIELD
[0004] This invention relates to servomechanism control systems and, in particular, to a high performance servomechanism control system and method implemented with feedforward compensation and feedback control to improve system speed and accuracy.
BACKGROUND OF THE INVENTION
[0005] Typical servomechanism control systems are implemented with feedback and feedforward elements, which cooperate to produce a response to a command input. In general, the servomechanism system error (the difference between the command input and the system output in response to the command input) will be significant during and after a typical command trajectory. If high accuracy of the output is desired, settling time is allocated to allow the output of the system to settle to the command position within a specified operational error tolerance. Additional techniques are desired to reduce or eliminate the settling time and thereby enhance high performance servomechanism control.
SUMMARY OF THE INVENTION
[0006] Preferred embodiments of the invention implement techniques for modifying the command trajectory, the architecture of a servomechanism control system, or both, to reduce the servo error during and/or after the command trajectory.
[0007] An iterative refinement procedure generates for use by the servomechanism control system a corrective input, du, which significantly reduces the error between the desired and actual servomechanism control system outputs. In one embodiment, a uniquely identified plant model is employed in the iterative refinement procedure to compute an approximate gradient that improves the performance and reliability of the refinement procedure. In another embodiment, the actual plant response is used in place of the identified model in the iterative refinement procedure. This is accomplished by time-reversing the stored error signal from a training run, before applying it to the plant to generate an update to the corrective input signal du.
[0008] The iterative refinement procedure entails using a typical plant model in place of a uniquely identified model for each particular plant to simplify and accelerate the iterative refinement procedure. An input stream of characteristic move trajectories is used in the training process to develop a corrective signal du that optimizes the servomechanism response for that particular input stream. The training trajectories and resulting du correction are then used to design a corrective input generator preferably implemented with a FIR filter that generates a du corrective signal for an arbitrary command trajectory.
[0009] This invention optimizes servomechanism control system performance by accounting for tolerances and variations specific to each set of hardware, without necessarily requiring the use of complex servomechanism control system model identification. This optimization is applicable even when the servomechanism control system is driven by arbitrary command trajectories.
[0010] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows the architecture of a servomechanism control system designed to achieve high-speed, precise operation of a physical plant.
[0012] FIG. 2 is a block diagram of a corrective input generator that refines the input command stream applied to the control system of FIG. 1 .
[0013] FIG. 3 is a block diagram of a particular implementation of the corrective input generator suitable for use in the control system of FIG. 1 .
[0014] FIG. 4A shows the dynamic transfer function from the measured physical plant output to the load position of the control system of FIG. 1 .
[0015] FIG. 4B shows the transfer function of a notch filter designed to counteract an amplitude spike in the dynamic transfer function of FIG. 4A .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] FIG. 1 shows the architecture of a motion control system 10 designed to achieve high-speed, precise operation of a physical plant (G) 12 . In a preferred embodiment, physical plant 12 is a high-speed scanner composed of scanning, mirrors commonly used in high performance laser micromachining and power drive electronics. Control system 10 is configured to improve the motion performance of one of the scanning mirrors of the high-speed scanner. The feedback signal, y, that is used to close the servo loop is measured through a joint encoder forming a part of the scanner. A dynamic transfer function (S) 13 models the coupling between the measured (feedback) position and the actual scanning mirror position. Separate design control systems 10 can be similarly configured for the other scanning mirror or other scanning mirrors of the high-speed scanner.
[0017] Control system 10 receives a move command input stream applied to a feedforward controller (F) 14 and a corrective input generator (P) 16 . The move command input stream can contain position, velocity, and acceleration components, or feedforward controller 14 can be implemented to expand a move command to compute these components. The output of feedforward controller 14 and corrective input generator 16 are applied through associated summing junctions to, respectively, plant 12 and a feedback controller (H) 18 of a servomechanism loop 20 . Feedforward controller 14 is designed to match the inverse of the dynamics of plant 12 within a limited frequency range to improve plant tracking performance at higher frequencies. Corrective input generator 16 profiles the move command input stream, u, to produce a refined input stream, u*, that compensates for the remaining closed-loop imperfections to further improve the servomechanism performance. The design, construction, and operation of corrective input generator 16 is described in complete detail below.
[0018] In the preferred embodiment described, physical plant 12 is a Model 6220H Moving Magnet Closed Loop Galvanometer Based Optical Scanner manufactured by Cambridge Technology, Inc., Cambridge, Mass., and a suitable power drive. Feedforward controller 14 and feedback controller 18 are preferably combined in a digital galvanometer controller, which a skilled person could readily design to provide a 5 kHz closed-loop system bandwidth in an implementation using the Model 6220H galvanometer.
[0019] FIG. 2 shows a block diagram of corrective input generator 16 in preferred implementation includes a finite impulse response (FIR) filter 28 , which corrects for deviations of output signal y from ideal behavior. With reference to FIG. 2 , corrective input generator 16 receives move command input stream u and applies it to a delay module 30 and to FIR filter 28 to advance its output 32 with respect to the direct signal path of move command input stream u. An output 34 of module 30 and output 32 of FIR filter 28 are combined at a summing junction 36 to produce at its output 38 a refined input stream u*, which for a zero delay introduced by delay module 30 can be expressed as
u*=u+du,
where du is an incremental correction factor applied to a move command input. The general case in which the delay is nonzero can be expressed as
u* ( n )= u ( n−m )+ du ( n ),
where n is the time index and m is the number of time steps the command inputs are delayed relative to output 32 of FIR filter 28 .
[0020] The objective is to construct a FIR filter 28 with a set of filter coefficients that provide a generic solution of du values for all possible move command inputs, which can represent beam position moves of different lengths (e.g., short, medium, and long distances) and different move length sequences (e.g., short distance move, followed by another short distance move, followed by a long distance move). The approach for constructing FIR filter 28 entails first determining the incremental correction factors du for a finite set of command inputs u and then calculating the coefficients of FIR filter 28 . This approach is carried out by a procedure that modifies the command input in an iterative manner to improve the match between the desired and actual system outputs. The stepwise iterative refinement procedure is as follows:
[0021] Step 1 entails initially setting du=0.
[0022] Step 2 entails passing u*=u+du through control system 10 and measuring the error stream, e, shown in FIG. 1 . Thus, for du=0, u*=u, and e=u−y.
[0023] Step 3 entails comparing e to an operational tolerance, and if e is within the operational tolerance, ending the iterative procedure. The operational tolerance is defined by a cost function
J ( u ) = ∑ k = 0 ∞ [ y d ( k ) - y ( k ) ] 2 ,
where y d is the desired output and y is the measured output in response to the input stream u. The improvement in match is, therefore, defined as a reduction in the cost defined by J(u).
[0024] Step 4 entails, in the event error stream e is insufficiently small, reversing e in time and passing the time-reversed error stream, e*, through control system 10 as a command (even though it is an error measurement); collecting the measured output stream y* e produced in response to e*; time-reversing the output stream y* e to form y e ; setting du next =du+α·y e , where α is a dynamically adjusted correction gain or scale factor; and repeating Steps 2 - 4 for a number of iterations until e meets the operational tolerance constraint.
[0025] The value of α defined in Step 4 should be sufficiently small that first order approximations hold for the expression
J ( u+du )= J ( u )+∇ J ( u )· du,
such that setting du as du=−α∇J(u) with α>0, will, therefore, yield
J ( u+du )= J ( u )−α(∇ J ( u )) 2 ,
which will ensure a reduction in the cost function J. During iterative refinement, the value of α is adjusted dynamically, beginning in the preferred embodiment, with α 0 =0.3. If the cost improves during one iteration, α is increased by 0.05 for the next iteration to a maximum of 0.6. If the cost degrades during one iteration, α is reduced by a factor of 2 and the current iteration is repeated, with the reduced refinement value of α. This reduction of a continues until an improvement is achieved.
[0026] An Alternative Step 4 entails passing error stream e by mathematical simulation as a command through an adjoint closed-loop system, which is a computer modeled adjoint of a linear time invariant (LTI) model of the physical closed-loop system that comprises plant (G) 12 , feedback controller (H) 18 , and feedforward controller (F) 14 ; calculating the output stream y; and setting du next =du+α·y e The Alternative Step 4 uses a simulated adjoint system, which is created by mathematical modeling. Step 4 entails using the actual physical system to experimentally collect a measured output. Alternative Step 4 is inferior because it requires not only creation of a model but also the availability of a computer to do so.
[0027] The conclusion of the iterative refinement procedure produces a refinement stream du* such that the composite input u*=u+du yields a very good match to the desired output stream y d . The refinement stream du* works, however, only for one particular input stream u to match a particular desired output stream y d . Corrective input generator 16 transforms refining a particular input stream to a generic solution that works satisfactorily for arbitrary inputs. To do so, corrective input generator 16 implements a correction mapping to generate a similar refinement du* when its input is the original input stream u. A FIR filter is preferred in implementation of corrective input generator 16 because a FIR filter provides guaranteed stability, is of limited scope, and has coefficients calculated in a straightforward manner by applying standard least-squares algorithms.
[0028] The following describes a training profile that comprises various move lengths from which global FIR coefficients can be obtained immediately without having to assemble data from different input streams. The iterative refinement described above for N number of experimental command move lengths used in the teaching process can be expressed as
u 1 , u 2 , . . . u N →du 1 , du 2 , . . . du N N<∞
The objective is to design a correction filter to map each u value to a corresponding du value. The FIR algorithm, which is embedded in a function of sum of products, can be expressed as
Δ( z )= a 0 z m +a 1 z m-1 + . . . +a n z n-m ,
where a 0 , a 1 , . . . , a n represent the filter coefficients and m represents the FIR anticipation; i.e., m is the number of time steps the FIR filter signal path is ahead of the direct signal path. Numbers m and n are chosen in accordance with a trial and error process, and a 0 , a 1 , . . . , a n are calculated through a least-squares algorithm. The quality of the resulting least-squares fit is assessed by observing the residual error. If the residual error is small, then control system 10 is operated with FIR filter 28 in place to determine how well it performs. If the control system performance is unacceptable, n, m, or both, are modified and new coefficients are calculated to start over the process.
[0029] The final configuration corrective input generator 16 of control system 10 equipped with the Cambridge Technology, Inc. Model 6220H galvanometer constitutes a 320-tap filter with a 160 kHz update rate and an anticipation of 80 taps to insert a 0.5 msec delay (shown as delay module 30 ) in the direct move command path but not in the path of FIR filter 28 . This enables creation of an effectively non-causal filter (with 80 of the 320 taps before n=0). To ensure FIR filter 28 is a zero DC gain filter, the sum of all of its coefficients is zero. One way of accomplishing this result is to solve the first 319 coefficients and then to set the last coefficient to the negative sum of the first 319 FIR coefficients. The first 319 FIR coefficients are the least-squares solution to the problem
Uh=du,
where h=[h 1 h 2 . . . h 319 ] T are the independent FIR coefficients and du=[du 1 du 2 . . . du M ] T is the correction sequence derived from a single training profile or assembled from multiple refinement runs.
[0030] The U matrix, which has 319 columns and M number of rows, contains the initial (ideal) input sequence in circular permutations, i.e.,
u m u m - 1 ⋯ u m + 1 u m ⋮ ⋮ u M u M - 1 ⋮ u 1 u M u 2 u 1 ⋮ ⋮ u m - 1 u m - 2 ⋯ .
The standard least-square solution can be obtained from
h =( U T *U ) −1 *U T *du.
The number of experimental command move lengths from which the FIR filter coefficients can be derived is N=2, one experiment representing a shorter length move command and the other representing a longer length move command.
[0031] An alternative way to ensure FIR filter 28 is a zero DC gain filter is to recognize that to satisfy the condition Δ(1)=0, z=1 has to be a root of the equation. The expression of Δ(z) is
Δ( z )=(1 −z −1 )·Δ′,
in which all of the coefficients of Δ′ are determined. FIG. 3 shows a block diagram of an alternative corrective input generator 16 ′ implemented with a reconfigured FIR filter 28 ′ as described above.
[0032] The scanning mirror of galvanometer 12 steers a laser beam toward a desired target location. Ideally, the actual mirror position, z, is directly proportional to the measured scanner position, y, or z=cy, where c is a known or measured constant value. Because the scanner position is measured through the joint encoder, the actual position of the mirror set at the free end of the scanner shaft does not match the measured position of the scanner shaft when it undergoes deflection during high acceleration position switching conditions. One reason for this difference is the finite stiffness of the mechanical coupling between the scanner shaft and the mirror. Thus, in reality, z=Sy, where S represents a dynamic filter characterizing the coupling between the measured scanner position and the actual mirror position on a Cambridge Technology, Inc. Model 6220H galvanometer.
[0033] FIG. 4A shows the dynamic filter transfer function S, which exhibits a peak amplitude value or spike at about 10 kHz. To compensate for the dynamic filtering effect, a system inverting notch filter having a transfer function as shown in FIG. 4B to counteract the 10 kHz spike is implemented in Step 2 of the iterative refinement procedure, in which originally e=u−y. With a notch filter implementation contributing to the determination of FIR filter 28 , e=Nu−y, where Nu is the notch filtered version of u. The notch filter compensation is made part of the calculation of FIR filter 28 to prevent the iterative refinement process from attempting to compensate for tracking errors about the notch frequency, inasmuch as the scanner measured position and actual mirror position are shown to diverge significantly in this frequency range.
[0034] The use of corrective input generator 16 implemented as described above and installed in a laser beam positioning system enables operating a galvanometer at higher accelerations and wider bandwidths than those previously used to position a laser beam. The consequence is an increase of about 25 percent in target specimen servo performance.
[0035] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. For example, alternative implementations of a corrective input generator may include, inter alia, an infinite impulse response (IIR) filter, combination IIR and FIR filters, or nonlinear filtering approaches such as neural networks. The scope of the present invention should, therefore, be determined only by the following claims.
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Preferred embodiments of the invention implement techniques for modifying the command trajectory, the architecture of a servomechanism control system, or both, to reduce the servo error during and/or after the command trajectory. An iterative refinement procedure generates for use by the servomechanism control system a corrective input, du, which significantly reduces the error between the desired and actual servomechanism control system outputs. In one embodiment, a uniquely identified plant model is employed in the iterative refinement procedure to compute an approximate gradient that improves the performance and reliability of the refinement procedure. In another embodiment, the actual plant response is used in place of the identified model in the iterative refinement procedure. This is accomplished by time-reversing the stored error signal from a training run, before applying it to the plant to generate an update to the corrective input signal du.
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BACKGROUND OF THE INVENTION
Pulse oximetry is a well known technique for non-invasive measurement of oxygen saturation in the blood of a living person. Generally pulse oximeters measure changes in the color of the arterial blood caused by changed in the ratio of hemoglobin and oxyhemoglobin present. The arterial blood is distinguished from venous blood and other tissue by its pulsatility.
Conventional pulse oximeters measure light transmittance through or reflectance from the blood at two wave lengths, e.g. red and infra-red. Measurements of the pulsatile and nonpulsatile components of the red and infra-red output signals are then processed using a relationship derived form the Lambert-Beers, law to compute oxygen saturation.
Some oximeters scale the magnitudes of the resultant signals making the non-pulsatile components equal so that the ratio of the pulsatile components relates directly to oxygen saturation. U.S. Pat. No. 4,407,290 to Wilbur for Blood Constituent Measuring Device and Method discloses an oximeter which scales the analog red and infra-red output signals so that their constant components are equal and then subtracts a d.c. voltage having a magnitude equal to that of the d.c. component. This enables the signals to be compared using the Lambert-Beers relationship with a simplified computation. However, the analog scaling and subtraction can provide a source of error because of limitations of the circuit and the Lambert-Beers computation, although simplified, is still complex to calculate.
Another approach, as exemplified by the pulse oximeter disclosed in European Patent Application No. 83304949.8, computes the ratios required for the Lambert-Beers relationship. A look-up table is used to apply the relationship without actually performing the mathematical manipulations required by Lambert-Beers. Although this method reduces computation time it is still prone to error resulting from deviations between empirical and theoretical factors.
SUMMARY OF THE INVENTION
In order to overcome the aforementioned shortcomings of prior art oximeters, the present invention teaches the use of a simplified oximeter design with improved accuracy and reduced calculation time. More specifically, the invention includes a pulse oximeter for measuring oxygen saturation in the blood of a person with means for directing light having a first wave length toward a tissue surface and the blood carried thereunder, means for directing light having a second wave length toward the tissue surface and the blood, and means for sensing the light of first and second wave lengths after its intensity has been affected by the color of the blood and for producing an electrical signal with a magnitude that is a function of the color of the blood and the pulse of the person, the signal being separable into a constant component and a pulsatile, i.e., time varying component, and means responsive to the electrical signals for determining a numerical measurement of oxygen saturation including charge storage means having an input terminal to which the electrical signal is applied and an output terminal at which there is produced an output signal having a waveform corresponding substantially to that of only the time varying component and substantially independent of the constant component, the determining means including memory means for storing representations of empirical numbers corresponding to predetermined oxygen saturation levels for comparison with Lambert-Beers ratios calculated from the pulsatile and composite electrical output signals and for calculating oxygen saturation levels as a function of the addresses of the empirical numbers in memory.
It is therefore an object of the invention to determine saturation by comparing the measured red and infra-red signal levels resulting from transmission of light through or reflection of light from blood with empirically derived data.
Another object of the invention is to make comparisons between the measured signal levels and empirical data more rapidly than computation of the Lambert-Beers formula.
Still another object of the invention is to provide a measure of oxygen saturation corrected for factors which cause deviations from the theoretical Lambert-Beers predictions, irrespective of whether the factors are identifiable.
A further object of the invention is to increase the accuracy of oxygen saturation measurements by updating the empirical relationship between blood measurements and oxygen saturation as it becomes better defined.
Other and further objects of the invention will be apparent from the following drawings and description of a preferred embodiment of the invention in which like reference numerals are used to indicate like parts in the various views.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a part of the preferred embodiment of the invention in use in its intended environment.
FIG. 2 is a schematic block diagram of the preferred embodiment of the invention.
FIG. 3 is a timing diagram of some of the switching signals employed in the preferred embodiment of the invention.
FIG. 4 is a graphic view of signals developed in the preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 of the drawings there is shown a sensor 2 (conventionally mounted in a housing not shown) which is adapted to be placed over the vascularized tissue of a patient, e.g., on a finger or ear lobe, whose hemoglobin oxygen saturation is to be measured. Mounted within the housing are two light emitting diodes (LEDs) 2 and 4 respectively. LED 2 emits light at a frequency of 660 nanometers and LED 4 emits light at a frequency of 940 nanometers. The light emitting surfaces of the LEDs 2 and 4 are directed at an opening in the housing in which the patient's vascularized tissue is received. A photodiode 10 is mounted on the opposite side of the housing with it slight sensitive surface orthogonal to the axis of maximum light emission from the LEDs, such that it receives light that has been transmitted through the tissue.
Pulses are alternately applied to the LEDs 2 and 4 under the control of a microprocessor 16 of a digital computer 12 shown in FIG. 2. The computer 12 includes, in addition to the microprocessor 16, a random access memory (RAM) 13 and a read only memory (ROM) 15. In the ROM 15 there is stored a program for calculating the Lambert-Beers ratio from the respective amplitudes of the pulsatile and constant components of the measured light transmissions through the blood, as known in the art, but which does not perform the logarithmic computation required by the Lambert-Beers law. There is also stored, a table with addresses corresponding to predetermined oxygen saturation values and, for each, a corresponding number equal to he ratio that would be calculated from the red and infra-red signal outputs developed in the course of monitoring a patient whose oxygen saturation level was equal to the respective saturation value. Unlike oximeters which compute saturation from logarithmic formulas based on the classical Lambert-Beers relationship or their Taylor series approximations, in accordance with the invention saturation is determined by comparing the Lambert-Beers ratio calculated for the measured red and infra-red signal levels with empirically derived data.
An area of the ROM 15 contains values of the empirically derived ratios with which the Lambert-Beers ratios derived from the pulsatile and constant component amplitudes are compared, in the form of the aforementioned table. In the preferred embodiment of the invention, the table contains only those empirically derived ratios which correspond to equally spaced discrete saturation levels. Saturation is calculated by comparing the value of the measured Lambert-Beers ratio with the values in the table until it is found to lie between two consecutive table values. Then the address of the match in the table gives the saturation value from the following formula which is simply calculated.
Saturation %=100-Address.sub.min
where Address min is the lower of the two addresses of the ratios between which the measured ratio lies.
For example, the table may appear as follows:
______________________________________Address Lambert-Beers Ratio______________________________________1 R12 R23 R34 R45 R5. .. .. .______________________________________
where R1 is the ratio corresponding to a saturation level of 99.5%, R2 correspond to 98.5%, R3 corresponds to 97.5%, etc. If the measured ratio lies between R3 and R4, saturation is computed as 100-3=97%.
The integer result is sufficiently precise for most medical applications. Further precision can be obtained by using ratios corresponding to more closely spaced saturation levels in the table.
The foregoing approach provides the following benefits. Comparisons between the measured signal levels can be made more rapidly than the computations required by use of the Lambert-Beers relationship can be done. Hence an improvement in system computation time is achieved. Additionally, correction is made for factors which cause deviations from the theoretical Lambert-Beers predictions, even when the factors are not individually identifiable. Furthermore, as more is learned concerning the expected relationship between red and infra-red signal values and oxygen saturation and as more empirical data is analyzed, the saturation table can be updated by the mere expedient of replacing the ROM 15 with one containing the updated table. It is also possible to employ electrically erasable programmable read-only memories (E 2 PROMS) to enable updating without ROM replacement.
A timing generator 14 is connected to an interrupt input of the microprocessor 16 and periodically applies interrupt signals to the microprocessor 16 to indicate that new data has been digitized and is available for input. The timing generator 14 is driven by a 4 MHz signal derived from the crystal clock oscillator output of the microprocessor 16. The timing signals for sequentially pulsing the LEDs 2 and 4 are derived by frequency dividers in the timing generator 14.
Constant current drive circuits 42 and 44 respectively connected to the cathodes of the respective LEDs 2 and 4, are turned on and off in response to application of the timing signals from the timing generator 14. When actuated by the timing signals from the timing generator 14, the constant current drive circuits 42 and 44 provide constant currents, the magnitudes of which depend on the amplitudes of the LED intensity signals generated by respective LED intensity signal generators 46 and 48.
The LED intensity signal generators 46 and 48 have respective digital inputs connected to the bus 40. In the event that the red and infra-red signal inputs to the analog to digital converter 36 are beyond the useful range of the A/D converter 36, e.g., due to skin thickness and pigment variations among subjects, the microprocessor responds by changing the level of the digital input signals to the LED intensity signal generators 46 and 48 thereby effecting the appropriate change in the level of the analog signals applied to the drive circuits 42 and 44.
Energizing signals are continuously applied to the LEDs 2 and 4 which are switched on and off under control of the microprocessor 16. In the preferred embodiment of the invention, enabling signals are sequentially applied to each of the LEDs every 640 microseconds, i.e. at 1.56 kHz as shown in FIG. 3 with the phase of the enabling pulses in the 940 nanometer channel being shifted with respect to the phase of the pulses in the 660 nanometer channel.
As seen in FIG. 3, after each occurrence of a pulsing of the 940 nM channel followed by a pulsing of the 660 nM channel, storage of values is done by the microprocessor 16 as will be explained hereinafter.
The single photodiode 10 is employed to sense the light output of each of the LEDs 2 and 4 which is transmitted through the blood stream in the vascularized tissue. The current output of the photodiode 10 is applied to a current to voltage convert 18 which includes an operational amplifier having a high slewing rate characteristic and an output which is connected to a demultiplexer and sample and hold circuit 20. The current to voltage converter 18 and the circuitry to which it is connected, other than the LEDs 2 and 4, and photodiode 10, is housed in a monitor 22 so that the sensor 1 may be small, light in weight, and economically manufactured. The demultiplexer 20 separates and distributes the voltage output of the current to voltage converter 18, which consists of a pulse train having two sets of peaks, between two channels, 24 and 26, corresponding to the 660 nM and 940 nM signals, respectively.
Each of the two channel outputs of the demultiplexer 20 is connected through a d.c. blocking capacitor 25, 27, to a respective amplifier 28, 30, the output of which is connected to a respective low pass filter 32, 34. The output signal from the demultiplexer 20 is shown in FIG. 4(a) without the effects of pulsing the LEDs 2 and 4. The waveform of the signals applied to the low pass filters 32, 34 is stepped and includes transients due to the switching of the demultiplexer 20. It is smoothed in the low pass filters 32, 34 wherein the high frequency transients are removed. The output of each of the amplifiers 28, 30 has a waveform as shown in FIG. 4(b) (ignoring the pulsing effects of the LEDs 2 and 4) which consists of an a.c. component superimposed on a zero d.c. level due to the blocking action of the capacitors 25 and 27. The magnitude of the D.C. level is a function of the intensity of the corresponding LED 2, 4, the sensitivity of the photodiode 10, the optical density of the tissue, and the mean volume of arterial blood, through which the light emitted by the LEDs must pass. The a.c. component has a frequency which varies with pulse rate and an amplitude which is a function of the change in volume of the arterial blood throughout the cardiac cycle, and the ratio of oxygenated to total blood hemoglobin, i.e. oxygen saturation.
An offset voltage generator 35 generates an analog offset voltage in response to a digital input from the computer 12 in order to allow the analog to digital converter 36 to operate with ground as the center point of the analog input voltages, i.e., the full waveform (negative and positive) of the variable component signal can be applied to the A/D converter 36 for deriving digital representations of the changes in light absorption of the blood at red and infra-red wave lengths. The value of the offset signal required to enable the analog to digital converter 36 to operate with ground as a center point is computed via the microprocessor 16 and a digital representation is applied to a corresponding digital input of the offset voltage generator 35. An analog offset signal having an amplitude corresponding to the digital offset signal is then applied to the analog to digital converter 36.
Respective 8 bit digital gain inputs in the amplifiers 28 and 30 periodically receive digital byte output from the microprocessor 16 which indicates the degree of correction needed to adjust the amplitude of the a.c. components at the outputs of the amplifiers 28, 30 to make optimum use of the dynamic range of the analog to digital converter 36 which is connected to a data input of the microprocessor 16. The gains of the amplifiers 28 and 30 are adjusted to a value approximately equal to two thirds (2/3) of the full dynamic range of the A/D converter 36. The amplified waveform at the output of the low pass filters 32 and 34 is of the form illustrated in FIG. 4(c). These waveforms are applied via bus 40 to the A/D converter 36 and the digital output thereof is applied to a data input of the microprocessor 16. The A/D converter 36 is operated to bipolar mode thereby enabling the full pulse waveform at the output of low pass filters 32 and 34 to be tracked.
For each output pulse appearing at the output of low pass filters 32 and 34 and digitized in the A/D converter 36, the voltage sample is tested to determine if it is a maximum or peak voltage. Detection of the peaks and troughs of the red and infra-red variable signal components is also done by the microprocessor. Various peak and trough detection algorithms known to those skilled in the art may be employed to derive the maxima and minima of each cycle of the pulsatile variable components, and their difference which is digitized to represent the measurement of the variable components.
In addition to testing each voltage pulse at the output of low pass filters 32 and 34 to determine whether or not it is a peak, a similar test is made to determine whether a trough in the signal waveform has been reached. The peak to trough value of each cycle of the a.c. output signals from the low pass filters 32 and 34 are also utilized in the derivation of oxygen saturation.
After each pulse is applied to the A/D converter 36, it is tested for validity so that spurious signals due to artifact can be suppressed. Two tests are made. First the elapsed time between each pulse and the preceding one is compared to a predetermined minimum time corresponding to a maximum anticipated pulse rate. In the preferred embodiment of the invention, a maximum pulse rate of 250 beats per minute is used to derive a predetermined minimum time of 240 milliseconds between pulses. The second test involves a comparison of the pulse period with the previous pulse period to determine if excessive variability exists, in which case the pulse is rejected.
The analog to digital converter 36 receives the output signal from the low pass filters 32 and 34 which represent the amplitudes of the variable components of the red and infra-red signals, respectively (see FIG. 4(c)), and the output signals from the demultiplexer 20 which represent the amplitudes of the constant components of the red and infra-red signals, respectively (see FIG. 4(a)). The amplitudes are digitized in the analog to digital converter 36 and applied via bus 40 to the microprocessor 16 of the computer 12.
The amplitudes of the digitized signals are converted to suitable form for use with the look-up table stored in the ROM 15. The corresponding oxygen saturation measurement is then displayed on a conventional liquid crystal seven-segment numerical display 60.
It is to be understood and appreciated that alterations, modifications and variations of and to the preferred embodiment described herein may be made without departing from the spirit and scope of the invention which is defined in the following claims.
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A pulse oximeter includes a capacitive d.c. blocking element to separate the time varying red and infra-red components of a light source transmitted through or reflected form the blood from the composite light signals. The magnitudes of the signal amplitudes are then digitized and converted for use as independent variables applied to a ROM based look-up table to determine blood oxygen saturation.
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CROSS-REFERENCES TO RELATED APPLICATION
[0001] This application claims priority to European Application No. 09 16 7361.6, filed Aug. 6, 2009, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates to a device for flow rate limitation at low differential pressures, in particular for limitation of the inhalation volume flow during the inhalation of therapeutic aerosols or of dosed pharmaceuticals in the form of aerosol into the lungs, or inhaled or exhaled breathing gases. Suitable pharmaceuticals include analgesics, anti-angina agents, antiallergics, antihistamines and anti-inflammatory agents, expectorants, antitussives, bronchodilators, diuretics, anticholinergics, corticoids, xanthins, antitumor agents, therapeutically active proteins or peptides such as insulin or interferon, antioxidants, anti-inflammatory substances, active ingredients or drugs as well as combinations thereof.
BACKGROUND
[0003] The administration of pharmaceuticals for treating respiratory diseases, such as asthma, as well as agents for the prophylactic treatment and treatment of mucous membranes of the tracheobronchial tract is preferred. The administration of corticoids is possible here.
[0004] The variable flow rate limitation in lung diagnosis apparatuses is a further preferred field of application. This is possible for all measurement methods using, e.g., aerosol particles for the diagnosis.
[0005] DE-A-199 12 461 discloses a device for limiting the flow at low differential pressures, particularly for limiting the inhalation flow volume during the inhalation of therapeutic aerosols. The device consists of a housing including an inhalation opening, an exhalation opening and a flow channel arranged therebetween, said flow channel having a flat, oblong cross-section with flexible large-surface walls. Depending on the differential pressure between the exhalation opening and the inhalation opening and the flexibility of the wall material, the cross-section of the flow channel can be reduced in size to suit a predetermined maximum inhalation flow volume.
[0006] The administration of pharmaceuticals in the form of an aerosol to the lungs by inhalation is essentially influenced by four factors: (i) the particle size and particle properties of the aerosol; (ii) the breathing volume of the patient; (iii) the patient's breathing flow; and (iv) the patient's morphometry and respiratory system. Whereas aerosols in suitable particle sizes have been produced by conventional systems, the parameters “breathing volume” and “breathing flow” (rate of breathing) are taken into account either insufficiently or not at all. This leads to an uncontrolled inhalation of the aerosol, which in turn leads to the fact that an insufficient amount of aerosol particles reaches the lungs or does not reach the areas to be treated (e.g., alveolar area) within the lungs.
[0007] EP-A-0 965 355 discloses a device for controlled inhalational administration of controlled-dosage drugs into the lungs. Said controlled inhalator comprises a closed recipient adapted to be charged with a predeterminable aerosol volume and from which the aerosol may be withdrawn via a control means for controlling the inhalation flow. Said control means of this known inhalator is either an adjustable valve or a critical nozzle. The breathing flow can be limited by using an adjustable valve or a critical nozzle.
[0008] EP-B-0 050 654 discloses an inhalation apparatus for administering pulmonary medication. Said inhalation apparatus comprises an inflatable envelope from which aerosol can be inhaled through a mouthpiece. This aerosol is introduced via a nebuliser into the inflatable envelope from a cartridge prior to inhalation. The mouthpiece has a restriction to limit the amount of air flowing through the mouthpiece during inhalation. This restriction limits the breathing flow during inhalation.
[0009] The two mentioned inhalation devices are characterised in that there is a flow rate limitation, i.e., during the inspiratory phase the breathing flow increases only slowly and the increase in breathing flow decreases constantly, leading to a constant flattening of the curve in the graph of the breathing flow vs. time. This flow rate limitation leads to the fact that, depending on the patient's inspiratory capacity, the breathing flow increases differently up to a maximum flow value. Thus, the flow is nearly kept at a constant level. This means that in the known inhalators, the intended flow rate limitation may lead to a more constant aerosol deposition in the lungs.
[0010] EP-A-1 036 569 discloses a method of and a device for providing a constant medicament dose for an inhalational administration at a low inhalation flow rate. This device consists of a closed container reducible in terms of volume, a mouthpiece connected to the container, on which a powder-aerosol generator can be connected for availability of the aerosol, a housing reducible in terms of volume, which surrounds the container on all sides and from which the mouthpiece is led out in sealed form, and means for controlling the inlet and outlet of air into or out from the zone between the container and the housing. The housing is adapted to be changed from a volume compression condition into an envisaged expanded availability condition for creating the envisaged aerosol volume in the container.
[0011] Furthermore, DE-A-100 29 119 discloses a device for the flow limitation at low differential pressures, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols. This device consists of a housing with at least an inlet opening, at least an outlet opening and a flow channel with at least a flexible wall arranged therebetween, whose cross-section is reducible to a predetermined size for a predetermined maximum inhalation volume flow depending on the negative pressure prevailing between the inhalation and exhalation openings and the flexibility of the wall material.
[0012] EP-A-1 136 921 discloses an inhalation device with a self-expanding container for a predetermined aerosol volume, means for introducing aerosol from an aerosol dispenser into the container and control means for controlling the inhalation flow. The control means keeps the inhalation flow at an essentially constant level during the entire aerosol inhalation period, wherein the control means comprises four flow channels which are radially arranged between a central inlet opening and outlet openings which are radially spaced apart from the inlet opening. The four radial flow channels are formed by four radially arranged, rectangular ribs extending from an essentially rigid wall to an essentially flexible wall, wherein one rib is longer than the others.
[0013] It is important regarding the intended administering of pharmaceuticals in the field of aerosol therapy that a certain inhalation volume flow is not exceeded. At the same time the patient's work of breathing at the inhalation device should be as little as possible. This means that during inspiration the patient should not have to create a great negative pressure so that the inhalation can also be performed by patients with bad lung function. In order to ensure the mobility of the patients, especially inhalators for administering emergency pharmaceuticals such as, e.g., fast acting beta-2-sympathomimetica, have to be administered with small handy inhalation devices. Prior art systems, however, could not integrate a breathing flow control in hand-held units due to the big dimensions of the flow rate limitation valves. Conventional dosed aerosol inhalation systems, be it for fluid or dry powder aerosols, exhibit a compact design, mostly operable with one hand. Such inhalation systems have no device to prevent the negative effect of a too high air flow on a good active ingredient deposition. An intended volume flow limitation during inhalation of therapeutic aerosols cannot be achieved in hand-held devices.
SUMMARY
[0014] It is an object of the present invention to provide a miniaturised device for flow rate limitation at low differential pressures for the use in hand-held devices, where the functional parameters remain constant or are even improved. This object is achieved with a device comprising the features of the claims.
[0015] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a first aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. Furthermore, the flexible wall has a control area A of less than 100 mm 2 . In the present invention the control area A is said area or partial area of the flexible wall which contributes to the control section of the flow limiter. This is the base area of the variable flow channel, reduced by the area of the inlet opening and the outlet opening. It is the area of the flow channel influencing the control, i.e., the “active” area. Preferably, the control area A is smaller than 75 mm 2 , more preferably smaller than 15 mm 2 .
[0016] In flow direction, the flow channel has a planar elongate cross-section a×b, formed by the flexible wall, a wall opposing the flexible wall, and two cross walls. This cross-sectional area is preferably smaller than 15 mm 2 . The height b of the flow channel is maximally 3 mm, preferably less than 2 mm. In the neutral or initial state, the cross-section a×b is constant along the length of the flow channel. The at least one flexible wall reduces the cross-section of the flow channel through the negative pressure in the flow channel created during inhalation of the aerosol. Thus, no dynamic pressure or pressure drop is created. The flow rate limitation device according to the invention is preferably formed such that a differential pressure of less than 30 mbar, preferably less than 10 mbar, depending on the size of the flow channel, is required for achieving a gas flow rate of maximum 30 l/min, preferably 12 l/min.
[0017] According to the invention, the shortest distance between inlet opening and outlet opening is smaller than 10 mm, preferably smaller than 5 mm, more preferably about 1.5 nun. The entire flow rate limitation device preferably has an overall outside length of less than 25 mm, preferably less than 22 mm, and has a width of maximally 15 mm, preferably maximally 12 mm. The entire height is preferably maximally 7 mm, preferably 4 mm. According to the invention, and in view of such dimensions, an inhalation flow of 30 l/min is achieved at a differential pressure of less than 30 mbar at the mouthpiece of the inhalation device. Preferably, a flow of 12 l/min at less than 10 mbar is also possible, depending on the size of the flow channel.
[0018] A further preferred characterising feature of the device of the invention is the ratio of control area A of the flow channel to the cross-section periphery (corresponding to 2×a+2×b) of the controlling, i.e., active flow channel in neutral state. This ratio is preferably less than 2, more preferably less than 1.4. A further preferred characterising feature of the device of the invention is the ratio of control area A of the flow channel to periphery U of the control area in neutral state. This ratio is preferably less than 2, more preferably less than 1 and most preferably less than 0.7. A ratio in this area enables a low pressure drop in the flow channel. Thus, the invention considerably differs from the prior art by its reduction in length and width of the base area of the variable flow channel at concurrently significantly reduced area-periphery ratio.
[0019] Moreover, according to a preferred embodiment, the ratio between the cross-sectional area of inhalation or exhalation opening to the control area A of the flexible wall is smaller 5 to 1, preferably smaller 3 to 1, and bigger 1 to 1.
[0020] Moreover, according to a preferred embodiment, the ratio of control area A of the flow channel to cross-section (a×b) of the flow channel in neutral state, i.e., without applied differential pressure, is less than 3, preferably less than 2.
[0021] Up to a differential pressure of 30 mbar, the flow rate limitation behaviour of the device of the invention exhibits a hysteresis graph, which, at falling differential pressure values, differs maximally 20% from the growth curve at rising differential pressures. More preferably, the deviation is maximally 10%, most preferably maximally 5%.
[0022] In unstressed condition, the flexible wall has a distance of more than 1 mm and less than 3 mm, preferably less than 2 mm and more preferably about 1.7 mm, from the opposite side. The distance determines the maximum flow value. Moreover, the flexible wall has a thickness of preferably 0.05 to 0.3 mm, more preferably of 0.1 to 0.2 mm, and most preferably of 0.15 mm. The thickness of the flexible wall is thus considerably smaller than the height of the flow channel. The flexible wall preferably consists of an elastic material and is, more preferably, a silicone membrane or consists of thermoplastic elastomers. The maximum length of the flexible wall is preferably about 25 mm and the maximum width is about 15 mm.
[0023] According to a further preferred embodiment, the inlet and/or outlet opening(s) have a chamfer of more than 0.5 and less than 1 mm at the respective edges facing the flow channel. The chamfer can be provided, e.g., in the form of a curve, such as in the form of a quadrant, preferably in a radius of 1 mm. According to the invention, this enables a reduction in the pressure difference since the pressure is better distributed in the flow channel and the pressure gradient is reduced.
[0024] The inlet opening and the outlet opening are arranged at opposite ends of the flow channel. Preferably the inlet opening and the outlet opening are arranged perpendicularly to the flow channel. The inlet opening and the outlet opening preferably have a diameter of 5 to 8 mm, more preferably of 6 to 8 mm, 5 to 7 mm, or 6 to 7 mm, most preferably of 6.5 mm. The centre axes of the inlet opening and the outlet opening are arranged at a distance from each other at preferably 8 to 12 mm, more preferably 8 to 11 mm, 8 to 10 mm, 9 to 12 mm, 9 to 11 mm, 10 to 12 mm or 10 to 11 mm, most preferably 10 mm.
[0025] As explained above, in the neutral, i.e., initial state, the flow channel has a constant rectangular cross-section in flow direction, wherein the width a is large compared to a small height b. In an alternative embodiment, however, the cross-section of the flow channel, in flow direction and without applied differential pressure, i.e., in the neutral or initial state, is not constant. Rather, the flow channel cross-section exhibits a minimum at a place where the flow channel cross-section enlarges upstream and/or downstream. This minimum is already present in the neutral state of the flow rate limitation device, i.e., it cannot be compared or mixed up with a minimum resulting from a negative pressure acting on the flow limiter and bending of the membrane. Particularly preferably, an enlarging cross-section is present both upstream and downstream. Preferably, the minimum is in the middle of the length of the channel. However, the invention also covers the alternative of an eccentric position of the minimum. Thus, in this embodiment, the height b increases from the minimum to the inlet or outlet opening. The area of the first and second housing components facing the flow channel are convexly formed in flow direction. However, according to the invention, only the wall of the first housing component at which the flexible mat abuts is convex, whereas the opposite wall of the second housing component is still planar.
[0026] A merely laminar flow and higher flow speed are achieved with this expanding cross-section of the flow channel. Thus, the control behaviour is further improved.
[0027] It is further preferred that the flow channel cross-section is not constant transversely to the flow direction, i.e., in width direction a, but exhibits a minimum, preferably in the middle and at least the area of the first housing component is convex also in width direction.
[0028] Moreover, the invention comprises a hand-held inhalation device with a flow rate limitation device according to the invention.
[0029] The compact design of the flow rate limitation device of the invention now enables a flow rate control in inhalation systems which could not have been equipped with such systems due to their sizes. The laminar, flexible membrane and significantly reduced control area enable very small sizes of the flow rate limitation valve. At the same time a flow control at reduced differential pressures can be obtained by the new arrangement of the inlet and outlet channels. A further positive effect resulting from the reduced design is a reduced hysteresis of the pressure-flow graph. This ensures that the identical flow values are achieved both at increasing and decreasing differential pressures.
[0030] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a second aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. The device according to the invention further provides an inhalation flow of 30 l/min at a differential pressure of less than 30 mbar at the mouthpiece of the inhalation device. Preferably, a flow of 12 l/min at less than 10 mbar, depending on the size of the flow channel, is also possible.
[0031] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a third aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. Further in the device of the invention, the ratio of control area A of the flow channel to the cross-section periphery (=2×a+2×b) of the controlling, i.e., active flow channel in neutral or initial state is less than 2, preferably less than 1.4.
[0032] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a fourth aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. Moreover, in the device of the invention, the ratio between the cross-sectional area of inhalation or exhalation opening to the control cross-sectional area of the flexible wall is smaller 5 to 1, preferably smaller 3 to 1, and bigger 1 to 1.
[0033] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a fifth aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. Moreover, according to the device of the invention, the ratio of control area A of the flow channel to cross-section (i.e., a×b) of the flow channel in neutral state, i.e., without applied differential pressure, is less than 3, preferably less than 2.
[0034] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a sixth aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. In unstressed condition, the flexible wall has a distance of more than 1 mm and less than 3 mm, preferably less than 2 mm and more preferably about 1.7 mm, from the opposite side. The distance determines the maximum flow value.
[0035] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to a seventh aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. Further, in the device of the invention, the ratio of control area A of the flow channel to periphery U of the control area in neutral state is preferably less than 2, more preferably less than 1 and most preferably less than 0.7.
[0036] The device for the flow rate limitation at low differential pressures according to the invention, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprises, according to an eighth aspect, a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween. The flow channel is restricted by a flexible wall extending along the flow channel. The flow channel cross-section exhibits in flow direction a minimum in the neutral or initial state.
[0037] According to the invention, the preferred embodiments described above in connection with the first aspect of the invention are also to be understood individually and/or in combination as preferred embodiments for the described second to eighth aspects of the invention.
BRIEF DESCRIPTION ON THE DRAWINGS
[0038] The invention is described in further detail in the following on the basis of the attached drawings.
[0039] FIG. 1 a shows a schematic top view of a flow rate limitation device of the invention according to a preferred embodiment;
[0040] FIG. 1 b shows a longitudinal section along A-A of FIG. 1 a;
[0041] FIG. 1 c shows a cross-section along B-B of FIG. 1 a;
[0042] FIG. 1 d shows a depiction of the actively controlling area A with its periphery U;
[0043] FIG. 2 shows a comparative depiction of the hysteresis graphs of the embodiment of the invention with prior art flow limiters;
[0044] FIGS. 3-5 show the individual curve progressions from FIG. 2 ; and
[0045] FIG. 6 shows a longitudinal depiction corresponding to FIG. 1 b for an alternative embodiment of the invention.
DETAILED DESCRIPTION
[0046] FIGS. 1 a to 1 c show a preferred embodiment of the flow rate limitation device of the invention from three different views. As is particularly evident from FIG. 1 b , the flow rate limitation device 1 consists of a housing 10 comprising a first housing part 11 and a second housing part 12 . The housing 10 is preferably elongate and for example cuboidal and is made, e.g., of plastics. The first housing part 11 has a recess into which the second housing part 12 is inserted. The second housing part 12 in turn exhibits a recess which, in assembled state of the housing 10 , forms a flow channel 23 . In the shown example, the recess in the second housing part has approximately the shape of a “0” (in FIG. 1 b of a horizontal “0”) with two parallel walls in the middle area, which are respectively connected left and right by a semicircular wall.
[0047] However, the assembly of the housing of two separate components is only exemplarily shown in the present case. The invention also comprises housing forms which do not consist of two separate components but are integrally formed of two portions connected with a folding mechanism. Thus, the two portions can be manufactured, e.g., in one process step, e.g., in an injection-moulding process. Alternatively, the housing of the inhalator can already be a part of the flow limiter housing.
[0048] An inlet opening 13 is provided in the first housing component 11 . In the preferred embodiment, said opening is circular, as is evident from FIG. 1 a . However, the invention also comprises embodiments, where several inlet openings are provided, as well as inlet openings of other cross-sectional shapes (e.g., oval or polygonal). The second housing component 12 , however, comprises an outlet opening 14 . Here, too, with regard to the outlet opening, several openings may be provided, which do not necessarily have to exhibit a circular cross-section. Still, a circular cross-section is preferred for both the inlet opening and the outlet opening. It is further preferred that exactly one inlet opening and exactly one outlet opening are provided.
[0049] In the preferred embodiment, a flexible membrane 16 of, e.g., silicone or thermoplastic elastomers, is inserted between the first housing component 11 and the second housing component 12 . As is evident from FIG. 1 b , the partial area of the membrane 16 shown on the left in the Figure planely abuts the downwards facing wall of the first housing component 11 . In the area of the inlet opening 13 , the membrane 16 , too, exhibits a corresponding opening to enable an air flow from the inlet opening 13 via the flow channel 23 to the outlet opening 14 . Alternatively, the flexible wall can also be injection-moulded to the housing component, e.g., by means of a two-component injection-moulding process. The membrane can be injection-moulded, e.g., to a front side.
[0050] The flow channel 23 between inlet opening 13 and outlet opening 14 is thus formed by the downwards facing wall 20 of the membrane 16 as well as by the wall 17 of the second housing component 12 opposing the membrane 16 . Furthermore, the flow channel 23 is restricted by the two side walls 18 and 19 . As is shown in FIG. 1 c , the flow channel has a rectangular cross-section in flow direction, having a large width a compared to a small height b.
[0051] When air is sucked through the outlet opening 14 , it flows into the flow channel 23 via the inlet opening 13 . Thus, a negative pressure is created due to the flow resistance. Said negative pressure in the flow channel 23 ensures that the membrane 16 bends inwardly and thus restricts the cross-section of the flow channel 23 . This partial area of the membrane 16 , which leads to a restriction of the flow channel, is considered to be the control area A of the flow limiter of the invention. The greater the negative pressure in the flow channel 23 , the greater the bending of the membrane 16 . Thus, the cross-section of the flow channel 23 alters depending on the differential pressure between inlet opening 13 and outlet opening 14 . Since the volume flow on the other hand depends on the cross-section of the flow channel 23 , the change in cross-section leads to a direct control of the volume flow and thus a flow limitation.
[0052] The actively controlling area is again depicted in FIG. 1 d , here hatchedly indicated. The periphery U of the actively controlling area consists of the two parallel straight partial sections as well as the two opposing circle segments.
[0053] By means of the degressive material flexibility, the force necessary for the bending of the membrane rises with increasing negative pressure in the flow channel up to a boundary value, which determines the desired minimum flow channel cross-section for limitation of the volume flow.
[0054] FIG. 6 shows a cross-section of another preferred embodiment of the flow rate limitation device of the invention. This flow rate limitation device l′ consists of a housing 10 ′ comprising a first housing part 11 ′ and a second housing part 12 ′. The housing is elongate and for example cuboidal. It is made, e.g., of plastics. The first housing part 11 ′ has a recess into which the second housing part 12 ′ is insertable or is inserted. The second housing part 12 ′ in turn exhibits a recess which, in assembled state of the housing 10 ′, forms a flow channel 23 ′. In the shown example, the recess in the second housing part 12 ′ has, as evident from FIG. 1 a for the above-described embodiment, approximately the shape of a “0” (in FIG. 1 b of a horizontal “0”) with two parallel walls in the middle area, which are respectively connected left and right by a semicircular wall.
[0055] The assembly of the housing of two separate components is also only exemplarily shown in this embodiment. The invention also comprises housing forms which do not consist of two separate components but are integrally formed of two portions connected with a folding mechanism. Thus, the two portions can be manufactured, e.g., in one process step, e.g., in an injection-moulding process. Alternatively, the housing of the inhalator can already be a part of the flow limiter housing.
[0056] An inlet opening 13 ′ is provided in the first housing component 11 ′. Said opening is, e.g., circular. However, the invention also comprises embodiments, where several inlet openings are provided, as well as inlet openings of other cross-sectional shapes (e.g., oval or polygonal). The second housing component 12 ′ comprises an outlet opening 14 ′. Here, too, with regard to the outlet opening, several openings may be provided, which do not necessarily have to exhibit a circular cross-section. Still, a circular cross-section is preferred for both the inlet opening and the outlet opening. It is further preferred that exactly one inlet opening and exactly one outlet opening are provided.
[0057] In the preferred embodiment of FIG. 6 , a flexible silicone mat 16 ′ is inserted between the first housing component 11 ′ and the second housing component 12 ′. As is evident from FIG. 6 , the partial area of the membrane 16 ′ shown on the left in the Figure planely abuts the downwards facing wall of the first housing component 11 ′. In the area of the inlet opening 13 ′, the membrane 16 ′, too, exhibits a corresponding opening to enable an air flow from the inlet opening 13 ′ via the flow channel 23 ′ to the outlet opening 14 ′. In this embodiment, too, the flexible wall can be injection-moulded, as explained above.
[0058] The flow channel 23 ′ between inlet opening 13 ′ and outlet opening 14 ′ is thus formed by the downwards facing wall 20 ′ of the membrane 16 ′ as well as by the wall of the second housing component 12 ′ opposing the membrane 16 ′. Furthermore, the flow channel 23 ′ is restricted by the two side walls 18 ′ and 19′.
[0059] As is shown in FIG. 1 c , the flow channel of FIG. 6 , too, has a basically rectangular cross-section in flow direction, having a large width a compared to a small height b. However, in the embodiment according to FIG. 6 , the cross-section of the flow channel is not constant in the neutral state in flow direction. Rather, the flow channel cross-section exhibits a minimum at a place where the flow channel cross-section enlarges upstream and/or downstream. In the example shown in FIG. 6 , an enlarging cross-section is present both upstream and downstream. The minimum is in the middle of the length of the channel. The invention also covers the alternative of an excentric position of the minimum. In other words, the height b increases from the minimum to the inlet or outlet opening. The area of the first and second housing components 11 ′ and 12′ facing the flow channel are convexly formed as shown in FIG. 6 .
[0060] When air is sucked through the outlet opening 14 ′, it flows into the flow channel 23 ′ via the inlet opening 13 ′. Thus, a negative pressure is created due to the flow resistance. Said negative pressure in the flow channel 23 ′ ensures that the membrane 16 ′ bends inwardly and thus restricts the cross-section of the flow channel 23 ′. This partial area of the membrane 16 ′, which leads to a restriction of the flow channel, is considered to be the control area of the flow limiter of the invention. The greater the negative pressure in the flow channel 23 ′, the greater the bending of the membrane 16 ′. Thus, the cross-section of the flow channel 23 ′ alters depending on the differential pressure between inlet opening 13 ′ and outlet opening 14 ′. Since the volume flow on the other hand depends on the cross-section of the flow channel 23 ′, the change in cross-section leads to a direct control of the volume flow and thus a flow rate limitation.
[0061] By means of the degressive material flexibility, the force necessary for the bending of the membrane rises with increasing negative pressure in the flow channel up to a boundary value, which determines the desired minimum flow channel cross-section for limitation of the volume flow.
[0062] The flow rate limitation device of the invention has, compared to the known prior art flow rate limitation devices, considerably smaller dimensions. Thus, the flow rate limitation device of the invention is smaller by a factor of approximately 5 compared to the flow limitation device of DE-A-100 29 119. According to the invention, however, the flow rate limitation device has not only been reduced in view of its dimensions (downscaling) but rather has been newly designed regarding various parameters in order to maintain at all the functionality in this considerably reduced size. A mere miniaturisation of the known flow rate limitation device would not lead to a functioning flow rate limitation.
[0063] The following Table compares an embodiment of the flow rate limitation device of the invention according to FIGS. 1 a - 1 c (right column) with two prior art devices. The flow rate limitation device of DE 199 12 461 is used, e.g., in the inhalation device prototypes of the company Activaero GmbH, Gemuenden, Germany, and the flow rate limitation device known from DE 100 29 119 is known as valve LimiX™ of the company Activaero GmbH, Gemuenden, Germany and is used, e.g., in the inhalation devices of the series Watchhaler™ of the company Activaero GmbH, Gemuenden, Germany.
[0000]
Embodiment of
DE 199 12 461
DE 100 29 119
the invention
Areas in mm 2
Inlet opening
78.53
28.27
33.18
Outlet opening
78.53
56.54
33.18
Base area membrane
8320
1290
200
Base area variable flow channel
4013.13
584.41
77.24
Control area A of the flow channel
3934.6
556.14
26.98
Cross-section flow channel in neutral state
(without differential pressure)
40
98.23
13.6
Periphery in mm
Periphery membrane in mm
424
127.23
60
Periphery U of the control area
805.96
236.73
39.58
Cross-section periphery flow channel in
82
85.96
19.4
neutral state (without differential pressure)
Ratios
Cross-section flow channel/cross-section
0.44
0.46
0.70
periphery flow channel in neutral state
Control area A of the flow channel/cross-
98.37
5.56
1.98
section flow channel in neutral state
Control area A of the flow channel/
4.88
2.35
0.68
periphery U of the control area
[0064] According to the invention, the flow rate limitation device has a control area of less than 100 mm 2 , in the example shown in the Table of only about 26.98 mm 2 .
[0065] Especially the combination of parameters “control area”, the ratio of control area to the periphery of the flow channel in neutral state and chamfer of the edges of the inlet and outlet openings results in a considerably improved mode of operation vis-á-vis known flow rate limitation devices, and this despite the significantly minimised design. This is apparent from FIGS. 2 to 5 .
[0066] FIG. 3 shows a hysteresis graph reflecting the flow rate limitation behaviour of the flow limiter of the invention according to FIGS. 1 a to 1 c . In FIG. 3 , as well as in FIGS. 2 , 4 and 5 , only an area of 0 to 30 mbar is shown, since this is the differential pressure range relevant to the flow rate limitation device of the invention. FIG. 3 clearly reveals that a nearly ideal, very flat hysteresis graph is achieved for the flow rate limitation device of the invention. The growth curve differs by only 1% from the downward curve at a differential pressure of 5 mbar. The difference is only 3.6% at a differential pressure of 10 mbar.
[0067] In comparison thereto, FIG. 4 shows the flow rate limitation behaviour of the flow limiter known from DE-A-100 29 119. FIG. 4 reveals the considerably more distinct hysteresis, where a difference of about 28% between rising and falling pressure curve ensues at both a differential pressure of 5 mbar and also at 10 mbar.
[0068] FIG. 5 shows the hysteresis for the flow limiter known from DE-A-199 12 461. Here, too, the hysteresis is significant with a difference of 20% at a differential pressure of 5 mbar and a difference of 38% at a differential pressure of 10 mbar.
[0069] The graphs of FIGS. 3 to 5 are again shown in FIG. 2 for a better comparison.
[0070] Thus, compared to the known flow limiters, a nearly ideal flow rate limitation behaviour is obtained by the flow rate limitation device of the invention.
[0071] Although the invention is illustrated and described in detail with the Figures and the corresponding description, said illustration and detailed description are only to be regarded as illustrative and exemplarily and not as being restricting to the invention. Naturally, experts may perform changes and modifications without going beyond the scope of the following claims. In particular, the invention also comprises embodiments with any combination of features which are mentioned or shown above in view of different aspects and/or embodiments.
[0072] The invention also comprises individual features in the Figures even if they are shown in connection with other features and/or are not mentioned above.
[0073] Furthermore, the term “comprise” and derivations thereof do not exclude other elements or steps. Likewise, the indefinite article “a” and derivations thereof do not exclude a plurality. The functions of several features mentioned in the claims can be fulfilled by a unit. The mere fact that certain dimensions are mentioned in different dependent claims does not mean that a combination of these dimensions cannot be advantageously used. The terms “essentially”, “about”, “approximately” and the like in connection with a property or a value define in particular exactly the property or the value. All reference signs in the claims are not to be understood as being restricting to the scope of the claims.
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The invention relates to a device for the flow rate limitation at low differential pressures, in particular for the limitation of the inhalation volume flow during the inhalation of therapeutic aerosols, comprising a housing with at least an inlet opening, at least an outlet opening and a flow channel arranged therebetween, wherein the flow channel is restricted by a flexible wall extending along the flow channel, characterised in that the flexible wall has a control area of less than 100 mm 2 .
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims priority on U.S. Provisional Patent Application No. 61/365,634, filed on Jul. 19, 2010, the contents of which are fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of power poles for the support and travel of electrical conductor cables designed to transmit electrical power.
BACKGROUND OF THE INVENTION
[0003] Electric transmission lines are the life-lines of a country's economy. Transmission lines interconnecting giant load centers with distant generation sources are vital to redistribute electrical power as required.
[0004] It is known to use treated wood poles to form transmission poles. However, chemicals used to treat wood poles have been found to contain carcinogens. Environmental and economic concerns stemming from the special disposal of treated wood poles have led to the search for alternatives to wood.
[0005] Concrete and steel are also used to form power poles. However, the weight of these materials makes cost of transport and installation excessive. Moreover, steel is highly conductive, while concrete structures expand and contract with temperature causing vertical cracking.
[0006] Resistance to corrosion is an additional common concern when using power poles. The ground in which the pole is placed, as well as the surrounding environment, can cause the pole to corrode, decreasing pole strength and pole life.
[0007] Cost of power pole manufacture is an additional concern. This cost results from materials used, scrap, waste, time of manufacture, and labor. It is therefore desirable to provide a power pole that can be inexpensively manufactured and transported and that is structurally sound and environmentally safe while being resistant to corrosion and environmental factors such as wind, moisture, heat, cold, etc.
[0008] There has been a great demand for composite power poles due to their relatively light weight, resistance to corrosion, and non-conductivity. Furthermore, composite materials generally use ecologically friendly manufacturing methods, especially when compared to steel power poles. However, the cost of composite materials on a cost per weight basis tends to be higher than traditional materials. Single wall composite structures are generally not sufficiently strong for power pole applications, and thus, often require additional support, such as a foam core. However, this results in added cost and can cause long term difficulty. Other designs have focused on tapered structures, however, such structures are not easily made using traditional composite power pole manufacturing processes, and thus may add significant cost.
SUMMARY OF THE INVENTION
[0009] A composite pole for supporting an electric transmission line is provided. In an exemplary embodiment, the composite pole includes a center shaft, and a first modular support shaft, the first modular support shaft including a plurality of first panels. In another exemplary embodiment, the center shaft has a plurality of center indentations, and each of the plurality of first panels has a first protrusion on a first side and a first indentation on a second side, and the first protrusion is configured to nest with one of the center indentations. In yet another exemplary embodiment, the pole further includes a second modular support shaft, the second support including a plurality of second panels, each of the plurality of second panels having a second protrusion on a first side, the second protrusion being configured to nest with the first indentation. In one exemplary embodiment, the first modular support shaft spans less than a length of the center shaft. In another exemplary embodiment, it spans more than the length of the center shaft. In a further exemplary embodiment, the pole further includes a second modular support shaft, the second modular support shaft surrounding less or more than the length of the first modular support shaft, the second module support shaft including a plurality of second panels. In yet a further exemplary embodiment, the center shaft is formed from a first composite material, the first modular support shaft first panels are formed from a second composite material, and the second modular support shaft second panels are formed from a third composite material. In another exemplary embodiment, the first, second and third composite materials are the same material. In yet another exemplary embodiment, at least one of the first, second and third composite materials is different from the other two of the first, second and third composite materials. In a further exemplary embodiment, the first modular support shaft has a circular or elliptical outer surface when viewed in cross-section. In one exemplary embodiment, the shaft may be circular, elliptical or polygonal when viewed in cross-section. In a further exemplary embodiment, the center shaft is hollow and is at least partly filled with a bulking material. In another exemplary embodiment, a reinforcing layer is provided between at least one of the plurality of first panels and at least one of the plurality of the second panels.
[0010] In another exemplary embodiment, a method is provided for forming a composite pole for supporting an electric transmission line. The method includes pultruding a first composite material forming a pultruded shaft, pultruding a second composite material forming a plurality of pultruded panels, installing the pultruded shaft into the ground, having a section extending above ground, and installing the plurality of panels to surround the pultruded shaft framing the composite pole. In another exemplary embodiment, each of the plurality of panels has a length that is less than a length of the shaft section extending above ground. In another exemplary embodiment, each of the plurality of panels has a length that is greater than a length of the shaft section extending above ground. In yet another exemplary embodiment, forming the plurality of pultruded panels includes pultruding all of the plurality of pultruded panels simultaneously. In a further exemplary embodiment, foaming the plurality of pultruded panels includes pultruding the second composite material through the same dye for forming all of the plurality of pultruded panels. In yet a further exemplary embodiment, forming the plurality of pultruded panels includes pultruding the second composite material to form a length of pultruded material and cutting the pultruded material at appropriate intervals to form the plurality of panels. In another exemplary embodiment, forming the plurality of panels includes pultruding the second composite material and cutting the pultruded second composite material at an appropriate length to form a first of the plurality of panels. In yet another exemplary embodiment, the method further includes continuing to pultrude the second composite material, and cutting the pultruded material to form a second of the plurality of panels. In a further exemplary embodiment, cutting includes cutting the pultruded second composite material proximate the dye. In another exemplary embodiment, the first and second composite materials are the same and in yet another exemplary embodiment, the first and second composite materials are different. In yet another exemplary embodiment, forming a pultruded shaft includes forming a hollow pultruded shall and the method further includes filling at least part of the hollow pultruded shaft with a bulking material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of an exemplary power pole assembly;
[0012] FIG. 2 is a cross sectional view of an exemplary power pole assembly;
[0013] FIG. 3 is a cut-away perspective view of an exemplary power pole assembly;
[0014] FIG. 4 is a cross sectional view of an exemplary power pole assembly; and
[0015] FIG. 5 is a cross sectional view of another exemplary power pole assembly.
[0016] FIG. 6 is a cross-sectional view of yet another exemplary embodiment power pole assembly.
[0017] FIG. 7 is a partial cross-sectional view of two panels interfacing with each other via a reinforcing layer.
[0018] FIG. 8 is a partial cross-sectional view of two layers interfacing with each other via a reinforcing layer to form the center shaft.
[0019] FIG. 9 is a partial exploded view of a coupling element used for coupling two panels along an axis.
DETAILED DESCRIPTION
[0020] FIG. 1 shows a view of a power pole assembly 10 according to an exemplary embodiment of the invention. As shown, the power pole assembly 10 includes a one-piece center shaft 20 , a first modular support shaft 30 , and a second modular support shaft 40 . In the shown exemplary embodiment, the center shaft 20 is hollow. The first modular support shaft 30 includes a plurality of panels 32 . The first modular support shaft 30 surrounds and extends along a portion of the length of the center shaft 20 (i.e., it does not extend the entire length of the center shaft). The first modular support shaft 30 may include any suitable number of panels. For example, the first modular support shaft 30 may include three panels, or it may include six panels. The second modular support shaft 40 includes a plurality of panels 42 . The second modular support shaft 40 surrounds and extends along a portion of the length of the first modular support shaft 30 . The second modular support shaft 40 may include any suitable number of panels. For example, the second modular support shaft 40 may include three panels, or it may include 6 panels. The second modular support shaft 40 may have the same number of panels as the first modular support shaft 30 or it may have a different number of panels than the first modular support shaft 30 . The panels 42 of the second modular support shaft 40 may be larger than the panels 32 of the first modular support shaft 30 . In the shown exemplary embodiment, each of the panels 32 , 42 are hollow.
[0021] Each of the plurality of panels 32 of the first modular support shaft 30 may be affixed to adjacent panels of the plurality of panels 32 . Additionally, each of the plurality of panels 32 of the first modular support shaft 30 may be affixed to the center shaft 20 . The plurality of panels 32 may be affixed using an adhesive. However, any suitable method may be used to affix the panels to each other or the underlying shaft. Similarly, each of the plurality of panels 42 of the second modular support shaft 40 may be affixed to adjacent panels of the plurality of panels 42 . Additionally, each of the plurality of panels 42 of the second modular support shaft 40 may be affixed to adjacent panels 32 of the first modular support shaft 30 . As depicted in FIG. 1 , the center shaft 20 and first and second modular support shafts 30 and 40 may be tiered. In other words, a length of the center shaft 20 extends the entire length of each of the first and second modular support shafts 30 and 40 and also extends beyond the length of each of the first and second modular support shafts 30 and 40 . Similarly, a length of the first modular support shaft 30 may extend the entire length of the second modular support shaft 40 and also may extend beyond the second modular support shaft 40 . A reinforcing layer 67 may be used between adjacent panels from adjacent modular support shafts, as for example between panels 32 and 42 as shown in FIG. 7 . In addition a reinforcing layer may be used between the panel(s) of the first modular support shaft and the center shaft. In addition the center shaft may be formed from multiple concentric sections 61 which interface via a reinforcing layer 67 , as for example shown in FIG. 8 . The reinforcing layers 67 may be adhered to the panels and/or the center shaft and/or center shaft sections. The reinforcing layers may be formed from a composite material designed to provide additional strength and/or stiffness. For example the reinforcing layers may be formed from glass or carbon fiber reinforced composite materials. They may also be formed from foam or balsa.
[0022] While only two modular support shafts are depicted in FIG. 1 , any suitable number of modular support shafts could be used. For instance, for shorter poles with relatively low loads, only one modular support shaft may be necessary. In other instances, it may be desirable to create much taller poles that can withstand greater loads, and accordingly, multiple modular support shafts may be used.
[0023] While the panels 32 and 42 may be in line with one another (i.e., a first panel 32 ends 33 are aligned with the ends 43 of a second panel 42 ) the ends 33 , 43 of panels 32 and 42 , and thus, the panels 32 , 42 , may also be offset or staggered, as shown in FIG. 2 . By staggering the panels, a power pole assembly 10 may have additional strength. Different strength and bend characteristics may be realized by aligning or staggering the panels.
[0024] The power pole assembly 10 may be buried in the ground. In other words, in an exemplary embodiment, each of the center shaft 20 , the first modular support shaft 30 , and the second modular support shaft 40 may be buried below ground.
[0025] FIG. 3 depicts a cut-away view of a power pole assembly 10 according to an exemplary embodiment of the invention. As shown, the power pole assembly 10 according to an exemplary embodiment of the invention may be modularly constructed. In other words, the center shaft 20 may be installed first. Subsequently, panels of the plurality of panels 32 may be individually installed adjacent to the center shaft 20 to form the first modular support shaft 30 . The plurality of panels 32 may be affixed to each adjacent panel and/or may also be affixed to the center shaft 20 as described above. Using the modular panels of embodiments of the present invention, additional modular support shafts may be added using additional panels after an initial completion of a power pole assembly 10 . In other words, as needs such as load requirements change, additional support shafts may be easily added to support the power pole assembly. Additionally, by using the modular panels of embodiments of the present invention, transportation of the smaller components may be easier and installation of the assembly may be simplified.
[0026] FIG. 4 depicts a cross sectional view of a power pole assembly 10 according to another exemplary embodiment of the invention. As shown, the center shaft 20 may have a hexagonal shape. A width of the hexagonal center shaft 20 , from one side to another, in an exemplary embodiment, may be about 1 foot 6 inches. The hexagonal center shaft 20 may have an indentation 24 at each side. Each indentation 24 , in an exemplary embodiment, may be about 3 inches wide and about 1 inch deep. The wall thickness of the center shaft 20 , in an exemplary embodiment, may be in about 0.125 inch to 1 inch. In another exemplary embodiment, the wall thickness of the center shaft is in the range of about 0.125 inch to 0.5 inch. A panel 32 of a first modular support shaft 30 may have a protrusion 36 designed to nest or mate with the indentation 24 of the center shaft 20 . The panel 32 , in an exemplary embodiment, may have a width 31 , at its widest point in the range of about 6 inches to 14 inches. The protrusion 36 , in an exemplary embodiment, may have a width of about 3 inches and a depth of about 1 inch. Similarly, the panel 32 may have an indentation 34 . The indentation 34 , in an exemplary embodiment, may have a width 35 of about 3 inches and a depth of about 1 inch. The panel, excluding the protrusion 36 , in an exemplary embodiment, may have a depth 37 of about 3 inches. The thickness 39 of the walls of the panels 32 , in an exemplary embodiment, may be in the range of about 0.625 inch to 0.075 inch. In another exemplary embodiment, the thickness of the panel walls may be about an inch. A panel 42 of a second modular support shaft 40 may have a protrusion 46 designed to nest or mate with the indentation 34 of the panel 32 . The panel 42 , in an exemplary embodiment, may have a width 41 , at its widest point, of about 1 foot 5 inches. Panel 42 may also have an indentation 44 . In an exemplary embodiment, the size of the protrusion 46 , indentation 44 , depth, and thickness of the panel 42 may be similar to that of the panel 32 . A panel 52 of a third modular support shaft 50 may have a protrusion 56 designed to nest or mate with the indentation 44 of the panel 42 . The panel 52 may have a width 51 , in an exemplary embodiment, at its widest point in the range of about 6 inches to 21 inches. In an exemplary embodiment, the size of the protrusion 56 , depth, and thickness of the panel 52 may be similar to that of the panel 32 . The use of the protrusions and indentations guide the installation of the panels, allowing for a relatively easy and quick build. In addition to the previously described methods of affixing the panels, an adhesive may also be used in the flat sections interfacing with the other flat sections of the other panels and/or in the indentations and protrusions to affix the indentations and protrusions that nest with one another. Additionally, while exemplary embodiments have been described where indentations are in the center shaft and protrusions in the inner surface of panels of the first modular support shaft (and subsequently indentations in the outer surface of each panel and subsequent protrusions in the inner surface of each panel), a power pole may also include protrusions in the center shaft and indentations in the inner surface of the panels of the first modular support shaft, etc. Also, while exemplary sizes and thicknesses have been described, any suitable sizes and thickness may be used depending on the desired size and shape of the power pole.
[0027] The center shaft 20 of the present invention may be any suitable shape. For instance, the center shaft 20 may be a polygon or an ellipse. In exemplary embodiments, the center shaft is circular or hexagonal, as depicted in the Figures. When the center shaft is circular, the panels may be crescent shaped. When the center shaft is hexagonal, the panels may be trapezoidal.
[0028] Any suitable number of panels may be used for each modular support shaft. For example, if the center shaft is circular, each modular support shaft may include three crescent shaped panels. In other embodiments, if the center shaft is circular, each modular support shaft may include six crescent shaped panels. However, in some embodiments, each modular support shaft may have a different number of panels. In another exemplary embodiment, if the center shaft is hexagonal, each modular support shaft may include six trapezoidal shaped panels. The size of the panels for each successive support shaft may become increasing larger in order to surround the circumference of the underlying support shaft. While the shown exemplary embodiments depict similar shapes for the center shaft and each modular support shaft (i.e., when the center shaft is a hexagon, the assembled first modular support shaft and all subsequent modular support shafts are also hexagons), the outer shape of the first and/or subsequent modular support shafts may be different than the underlying shape. While the inner surface of each modular support shaft may mate with the outer surface of the underlying modular support shaft or center shaft, the outer surface may be any shape. For instance, in an exemplary embodiment, the center shaft may be hexagonal and the first modular support shaft may have an inner surface that corresponds to the hexagonal shape of the center shaft, but an outer surface that is circular.
[0029] In order to reduce weight and cost, each of the panels and the center shaft may be hollow. Hardware, electrical and/or fiber optic cables may be passed through the hollow center shaft or through any of the panels forming the surrounding panels or shafts. In exemplary embodiments, the center shaft and the panels may be filled with a material, such as foam, or other bulking materials to help provide structural support for the power pole assembly. However, foam filling may not be necessary to provide sufficient structural support for the power pole assembly when sufficient modular support shafts are used according to embodiments of the invention.
[0030] FIG. 5 depicts a cross sectional view of a power pole assembly 10 of another exemplary embodiment of the present invention. As shown in FIG. 5 , a center shaft 20 , a first modular support shaft 30 , a second modular support shaft 40 , and a third modular support shaft 50 , may telescope on the interior as well as the exterior. In other words, while a length of the center shaft 20 may extend beyond the first modular support shaft 30 at a top portion of the center shaft 20 , a length of the first modular support shaft may extend below the center shaft 20 at a bottom portion of the center shaft 20 . By telescoping the interior of the power pole assembly at a bottom of the assembly, less material is used, reducing both weight and cost.
[0031] Additionally, in embodiments of the invention only the outermost modular support shaft may be buried below ground. In other words, rather than burying each of the center shaft and the other interior modular support shafts in the ground, only the outermost modular support shaft may be buried. Alternatively, some of the outermost modular support shafts or all of the modular support shafts may be buried in the ground, while the center shaft and optionally some interior modular support shafts may be above the ground.
[0032] In another exemplary embodiment, as for example shown in FIG. 6 , a power pole may only have interior telescoping. In other words, the length of the center shaft 20 may not extend beyond the length of the first modular support shaft 30 (i.e., the first modular support shaft 30 extends the entire length of the center shaft 20 and some additional length). Similarly, the first modular support shaft 30 may not extend beyond a length of the second modular support shaft 40 (i.e., the second modular support shaft 40 extends the entire length of the first modular support shaft 30 and some additional length). In any of the aforementioned exemplary embodiments, at least one modular support shaft may extend below the center shaft and may be embedded in the ground or other support structure.
[0033] In exemplary embodiments of the invention, the power pole assembly may be made of a non-conducting fiber reinforced composite material such as a composite of E-glass and a vinyl ester resin. Any suitable composite material may be used. Such compositions may be resistant to corrosion from the environment (i.e., wind and moisture) and the ground. Accordingly, the power pole assembly may be buried without risk of corrosion or rot. A power pole assembly made with composite materials may weigh 10 to 40 percent less than the weight of traditional wood poles, and much less than steel or concrete poles. The center shaft and each of the modular support shafts may be made of the same or different materials. Other reinforcements such as carbon fiber, high strength glass (S-Glass, R-Glass and similar), basalt fibers, aramid, etc (whether conductive or not) may be used as well to form the center shaft and/or panels. Other resin systems that may also be used may be polyester, epoxy, phenolic, urethane or thermoplastic. Additives or coatings may be used to protect from UV degradation or fire.
[0034] In exemplary embodiments of the invention, the composite materials of the power pole assembly may be formed using a pultrusion process. In the pultrusion process, continuous rolls of rovings, stranded mat and/or woven fibers are sent through a resin bath. The resin soaked fiber then proceeds through a die and heat source, which cures the resin soaked fiber in a desired shape. For example, the die may be in a circular shape to form a hollow circular center shaft. Or, the die may be in a crescent shape to form a hollow crescent shaped panel. The pultruded material is then cut into desired lengths to form a center shaft or panels.
[0035] One die may be used to make all center shafts. Then, prior to assembling a power pole assembly, the center shaft may be cut to a desired height. When a different size power pole assembly is desired, a center shaft from the same die may be formed by simply cutting the material to the desired height during or after the pultrusion process. Similarly, one die may be used to make all panels of each respective modular support shaft. In other words, because the panels of each respective modular support shaft may be the same size (i.e., each of the panels of the first modular support shaft are the same first size and each of the panels of the second modular support shaft are the same second size), one die may be used to form all the panels of a given modular support shaft. According to the needs of a particular power pole assembly, the panels may be cut to a desired height during or after the pultrusion process. If a panel of a different height is needed for a modular support shaft for a different power pole assembly, the panels may be made using the same die and then simply cut to the desired height during or after the pultrusion process. All panels required for each modular support shaft may be formed through a single die by being pultruded simultaneously. In another exemplary embodiment, the panels are pultruded sequentially. This may be accomplished by pultruding one panel at a time or by cutting each pultruded panel at a desired length during the pultrusion process or after the pultrusion process. By forming power pole assemblies according to embodiments of the present invention, less dies need to be made, as one die may be used to form the center shaft of different power pole assemblies, one die may be used to form the panels of the first modular support shaft of different power pole assemblies, and one die may be used to form the panels of the second modular support shaft of different power pole assemblies, etc.
[0036] There may be situations where the length of a panel may have to be limited as for example, because it has to be shipped to a certain location for installation, and the method of shipment, whether by truck or container, may limit to the length of the panel. In such case, the panel may be made in two or more sections that can be coupled together. There are various ways that one section may be axially coupled to another section to form a single linear panel. In an exemplary embodiment, a coupling member 70 may be formed that fits inside the panel sections 72 , 74 to be coupled as shown in FIG. 9 . In an exemplary embodiment, the coupling member is adhered or otherwise connected to the inner surfaces of panel sections 72 and 74 . In a further exemplary embodiment and as shown in FIG. 9 , the coupling member has at least a surface, such a surface 76 that mates with an inner surface 78 of the panels.
[0037] Although specific embodiments of the invention have been described above, the invention may have other variations as well. The present invention has only been described by way of exemplary embodiments. Specific descriptions are not intended as limitations of the invention. The current invention also covers other embodiments within the scope of the invention but not specifically described herein.
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Poles for supporting electric transmission lines and a method for forming such poles are provided. An exemplary pole includes a center shaft and a first modular support shaft. The first modular support shaft surrounds more or less of the length of the center shaft and includes a plurality of first panels.
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RELATED APPLICATIONS
This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/043,064 filed Apr. 7, 2008, which is incorporated herein by reference. This patent application is also a continuation-in-part of U.S. patent application Ser. No. 11/751,523 filed May 21, 2007, which issued on May 10, 2011 as U.S. Pat. No. 7,939,045 and is incorporated herein by reference, which is a continuation-in-part of U.S. patent application Ser. No. 10/733,805 filed Dec. 10, 2003, which issued on May 22, 2007 as U.S. Pat. No. 7,220,393 and is incorporated herein by reference, which claims the benefit of Canadian Patent Application No. 2413834, filed Dec. 10, 2002.
BACKGROUND
1. The Field of the Invention
This invention relates generally to chemical reactors, and more specifically to apparatus and methods for generating nitric oxide.
2. Background
The discovery of certain nitric oxide effects in live tissue garnered a Nobel prize. Much of the work in determining the mechanisms for implementing and the effects of nitric oxide administration are reported in literature. In its application however, introduction of bottled nitric oxide to the human body has traditionally been extremely expensive. The therapies, compositions, and preparations are sufficiently expensive to inhibit more widespread use of such therapies. What is needed is a comparatively inexpensive mechanism for introducing nitric oxide in a single dosage over a predetermined period of time. Also, what is needed is a simple introduction method for providing nitric oxide suitable for inhaling.
It would be an advance in the art to provide a single dose generator suitable for administration of nitric oxide gas. It would be an advance in the art to provide not only an independence from bottled gas, but from the need for a source of power for heat, or the like. It would be a further advance in the art to provide a disposable generator to be initiated by a trigger mechanism and operate without further supervision, adjustment, management, or the like. Likewise, it would be a substantial benefit to provide a system that requires a minimum of knowledge or understanding of the system, which might still be safe for an individual user to administer with or without professional supervision.
BRIEF SUMMARY OF THE INVENTION
In accordance with the foregoing, certain embodiments of an apparatus and method in accordance with the invention provide a self-contained reactor system. Nitric oxide may thus be introduced into the breathing air of a subject. Nitric oxide amounts may be engineered to deliver a therapeutically effective amount on the order of a comparatively low hundreds of parts per million, or in thousands of parts per million. For example, sufficient nitric oxide may be presented through nasal inhalation to provide approximately five thousand parts per million in breathing air. This may be diluted due to additional bypass breathing through nasal inhalation or through oral inhalation.
One embodiment of an apparatus and method in accordance with the present invention may rely on a small reactor. Reactive solids may be appropriately combined dry. Reactants may include nitrite compounds, such as potassium nitrite, sodium nitrite, or the like, nitrate compounds, such as potassium nitrate, sodium nitrate, or the like. The reaction may begin upon introduction of a heat. Heat may be initiated by liquid transport material to support ionic or other chemical reaction in a heat device.
An apparatus and method in accordance with the invention may include an insulating structure, shaped in a convenient configuration such as a rectangular box, a cylindrical container, or the like. The insulating container may be sealed either inside or out with a containment vessel to prevent leakage of liquids therefrom. Such a system need not be constructed to sustain nor contain pressure. Inside the containment vessel may be positioned heating elements such as those commercially available as chemical heaters.
In certain embodiments, chemical heaters may include metals finely divided to readily react with oxygen or solid oxidizers. Various other chemical compositions of modest reactivity may be used to generate heat readily without the need for a flame, electrical power, or the like.
Above the heating element or heater within the containment vessel may be located a reactor. The reactor may preferably contain a chemically stable composition for generating nitric oxide. Such compositions, along with their formulation techniques, shapes, processes, and the like are disclosed in U.S. patent application Ser. No. 11/751,523 and U.S. Pat. No. 7,220,393, both incorporated herein by reference in their entireties as to all that they teach.
The reactor may include any composition suitable for generating nitric oxide by the activation available from heat. The reactor may be substantially sealed except for an outlet, such as a tubular member secured thereto to seal a path for exit of nitric oxide from the reactor.
In certain embodiments, a system of water or salt water may be available in the container. In one embodiment, the water containers may be as simple as presealed bags, such as polyethylene bags that can be opened, cut, torn, or otherwise pierced in order to release water therefrom. Accordingly, a system may include a heating element or the reactor, such a water source to provide a chemical transport fluid, a piercing assembly for the water containers, a trigger for activating the piercing assembly, and blades, hooks, cutters, punches, or the like structured to open the bags containing water.
Upon triggering of the piercing assembly, the water is released from the water containers, vessels, bags, or the like, to be poured down through the assembly onto the heating elements where heaters are activated by the presence of a liquid. It has been found through experiments that adding the additional ionic content of salt improves the reaction rate of chemical heating systems.
Ultimately, an apparatus in accordance with the invention may include a cover through which an outlet penetrates from the reactor in order to connect to a cannula. This has been done effectively. It will also support a vent for steam generated by the heaters in the presence of the water used to activate the heaters. The system may be completely wrapped in a pre-packaged assembly. In one embodiment, a heat-shrinkable wrapping material may be used to seal the outer container of an apparatus in accordance with the invention. Thus, this system may be rendered tamper proof, while also being maintained in integral condition throughout its distribution, storage, and use.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which:
FIG. 1 is a perspective view of one embodiment of an apparatus in accordance with the invention to generate nitric oxide from a chemically active source of nitric oxide, as a result of exposure to heat;
FIG. 2 is an exploded view of the apparatus of FIG. 1 for generating nitric oxide;
FIG. 3 is a top plan view of an insulating container for the apparatus of FIG. 1 ;
FIG. 4 is a side elevation view of the box-like container of FIG. 3 ;
FIG. 5 is an end, elevation, cross-sectional view of the container (box) of FIGS. 3-4 ;
FIG. 6 is a top plan view of a cover for the container of FIGS. 3-5 ;
FIG. 7 is an end elevation view of the cover of FIG. 6 ;
FIG. 8 is a side elevation view of the cover of FIG. 6 ;
FIG. 9 is a side elevation view of a vent for the portable nitric oxide device of FIG. 1 ;
FIG. 10 is a top plan view of the vent illustrated in FIG. 9 ;
FIG. 11 is a front elevation view of a triggering pin for the apparatus of FIG. 1 ;
FIG. 12 a is an end view of the pin of FIG. 11 ;
FIG. 12 b is a side elevation view of the pin of FIG. 11 ;
FIG. 13 is a bottom plan view of a guiding rod for holding a compression spring used in the trigger device of the apparatus of FIG. 2 ;
FIG. 14 is a side elevation view of the guide rod of FIG. 13 ;
FIG. 15 is a front elevation view of a spacer used in the piercing assembly of FIG. 2 ;
FIG. 16 is a top plan view of the spacer of FIG. 15 ;
FIG. 17 is a top plan view of the mounting assembly for a blade of the piercing assembly of the apparatus of FIG. 2 ;
FIG. 18 is an end elevation view of the mounting assembly or carrier for blades in the piercing assembly of FIG. 2 , and corresponds to the apparatus of FIG. 17 ;
FIG. 19 is a side elevation view of the mounting assembly with blades in place, and corresponds to the apparatus illustrated in FIGS. 17-18 ;
FIG. 20 is a side elevation view of a base or base plate for supporting the blades in the piercing assembly of the apparatus of FIG. 2 ;
FIG. 21 is a top plan view of the base or base plate of the apparatus of FIG. 20 ;
FIG. 22 is a side elevation view of a cover plate for the blades in the piercing assembly of the apparatus of FIG. 2 ;
FIG. 23 is a top plan view of the cover plate of FIG. 22 ;
FIG. 24 is a side elevation view of a spring, used as a compression spring to drive the mounting assembly of FIG. 17 , with the blades installed to operate the piercing assembly of FIG. 2 ;
FIG. 25 is a top plan view of one embodiment of a containment vessel operating as a reactor for the nitric oxide generation from the chemical species contained therein;
FIG. 26 is a side elevation view of the reactor's containment vessel of FIG. 25 ;
FIG. 27 is a side elevation view of one embodiment of a tube configured to operate as an outlet for the reactor vessel of FIG. 25 ;
FIG. 28 is a perspective view of one embodiment of a shrink-wrap sleeve that is applied to contain the overall enclosure of the apparatus of FIGS. 1-2 ;
FIG. 29 is a perspective view of the apparatus of FIGS. 1-2 with the open lid upside down;
FIG. 30 is a partially cutaway top perspective view of the apparatus of FIG. 29 open with the liquid bags removed for viewing of the internal piercing apparatus;
FIG. 31 is a graph showing data for the temperature rise in degrees Fahrenheit of the reactor of FIGS. 2 , 29 and 30 using a variety of heaters including a single heater relying on water as the liquid, two standard heaters relying on water, and a single heater using salt water as the activating liquid;
FIG. 32 is a graph depicting the temperature response of the reactor of FIGS. 1-30 over time in both a single heater and double heater configuration;
FIG. 33 is a graph depicting the temperature response of the reactor of FIGS. 1-30 as a function of time when heated by a single heater and by double heaters; and
FIG. 34 is a chart depicting the released volume of nitric oxide from the reactor of FIGS. 1-30 superimposed over the temperature response thereof as a function of time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of various embodiments of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
Referring to FIG. 1 , an apparatus 10 may be configured as a portable nitric oxide device. In the illustrated embodiment, a container 12 or vessel 12 may provide insulation, liquid sealing, or both. Meanwhile, a fitting 14 or outlet 14 may be connected to feed nitric oxide to a line 15 proceeding toward a user, for distribution by a cannula, mask, tent, or the like.
In the illustrated embodiment, a trigger 16 or actuator 16 may be withdrawn from the apparatus 10 in order to trigger the initiation of a reaction generating nitric oxide. In certain embodiments, generation of nitric oxide may depend on temperature of reactants. The generation of heat (e.g., temperature) may rely on a reaction requiring moisture, which moisture may eventually be partially converted to steam needing to be vented. Accordingly, a vent 18 may vent the interior of the container 12 in order to avoid any buildup of pressure; in one embodiment, the entire container 12 may be sealed in a heat-shrinkable sleeve that maintains the integrity of the apparatus 10 during distribution, storage, and use.
Referring to FIG. 2 , an exploded view of the apparatus of FIG. 1 illustrates one embodiment of the apparatus 10 in accordance with the invention. In the illustrated embodiment, the outlet 19 , connected to feed through the fitting 14 and thus feed nitric oxide through the line 15 may be securely sealed to a reactor 20 . The reactor 20 may be formed by any of several suitable methods to contain the chemical constituents required to generate nitric oxide. A port 21 or aperture 21 may be formed to seal against the outlet 19 in order to discharge all of the generated nitric oxide to a location outside the apparatus 10 .
Below or around the reactor 20 may be located one or more heaters 22 or heating elements 22 . In the illustrated embodiment, the heaters 22 are formed to contain solid reactants in a non-woven fabric container. The reactants are stabilized by being completely dry. In the presence of liquid, ionic exchange promotes the reaction of the contained chemicals within the heaters 22 .
In order to contain any liquid to activate the heaters 22 , a containment vessel 24 may surround the heaters 22 , within the insulation container 26 or box 26 . In certain embodiments, the functionality of the containment vessel 24 and the insulated container 26 may be consolidated into a single structure. Likewise, in certain embodiments, the containment vessel 24 may actually be located external to the insulated container 26 .
In general, a liquid, and particularly a hydrating liquid such as water, salt water, or the like, may serve as an activation material. In the illustrated embodiment, the bags 28 containing salt water, water, or the like may be sealed for storage. In certain embodiments, the containers 28 may be capped, vented, or otherwise made resealable. However, in other embodiments, a fully disposable apparatus 10 may rely on inexpensive materials such as polyethylene film to form the containers 28 .
By any means, an opening assembly 30 (in the illustrated embodiment, a piercing assembly 30 ) may be actuated to open, pierce, or otherwise breach the sealing of the containers 28 of liquid. Upon piercing or otherwise breaching of the integrity of the containers 28 , the contained liquid then flows downward to be absorbed within the covering material of the heaters 22 . The presence of the liquid activates the chemical reactions within the heaters 22 , generating heat to initiate reaction of the chemical constituents contained within the reactor 20 .
A cover 32 may enclose the insulated container 26 , and may typically be formed of the same material. A vent 30 may vent steam from within the containment vessel 24 and the insulated container 26 in order to alleviate any pressure build up. Likewise, in order to direct the residual steam in a specific direction other than permitting it to escape about the interface between the cover 32 and the container 26 , a vent 18 may be advisable, required, or otherwise useful.
The outlet 19 for nitric oxide may penetrate through the cover 32 by means of an aperture 34 . The aperture 34 may be sealed against the outlet 19 in order that the steam generated from the heaters 22 escape substantially exclusively through the vent 18 , rather than near the fitting 14 and line 15 that may be subject to manipulation by the user.
Referring to 3 - 8 and 29 , the insulated container 26 may be formed in any suitable shape to contain all of the elements required for a single dosing of nitric oxide. Accordingly, the constituent structures of FIG. 2 may fit within the interior of the container 26 . Meanwhile, cover 32 may be fitted thereto.
The vent 18 may be formed to fit snugly through a penetration in the cover 32 . A flange thereof may be labeled with colors and text appropriate to warn of the elevated temperature thereof as a safety measure.
A pin may act as a significant portion of the trigger assembly 16 or trigger 16 . Upon removal of the pin, such as by a user pulling on a handle or ring secured thereto, the blades may be released to pierce the containers 28 holding the liquid required to initiate the reaction of heaters 22 .
A guide 36 or guide rod 36 may direct the blades of the piercing assembly 30 . A compression spring wrapped around the guide 36 or rod 36 may push the blades forward. Referring to FIGS. 13-23 , generally, while specifically referring to FIGS. 15-16 , the piercing assembly 30 may be configured to protect against inadvertent exposure to sharp instruments. A spacer 38 may provide room for operation of a blade assembly 39 or mount 39 holding blades 40 secured thereto.
For example, a “T”-shaped mounting assembly may secure two blades 40 a , 40 b that will eventually slide parallel to the base of the T, and along the same direction of the guide 35 or guide rod 36 . In the illustrated embodiment, an aperture in the foot of the T-shaped mount may run along the guide rod 36 , driven by the compression spring acting along the length of the rod 36 .
The blade assembly or mount 39 , together with its attached blades 40 may operate by sliding along an upper surface of the baseplate 42 . Two apertures on opposing sides or near opposing edges of the baseplate 42 may receive fasteners to penetrate a pair of corresponding spacers 38 . The spacers 38 form a clearance above the baseplate 42 for operation of the mount 39 .
A cover 44 or cover plate 44 may include a pair of apertures at or near opposing edges thereof to receive the same fasteners that penetrate the baseplate 42 . Accordingly, the cover plate 44 , or simply cover 44 , is spaced away from the baseplate 42 sufficient distance to receive the mount 39 and attached blades 40 therewithin. Thus, the blade assembly 39 or mount 39 with its attached blades 40 is effectively “garaged” between the baseplate 42 , and the cover plate 44 . Meanwhile, a compression spring 46 pushes against the base of the T-shaped mount 39 , driving the aperture therein along the guide rod 36 captured in the aperture.
A reactor 20 may include a principal containment vessel 50 . In one embodiment, a conventional “tin,” or metal can, may be formed by conventional technology available for canning. In other embodiments, the reactor 20 may rely on other structures such as fiber-reinforced composites, cylinders, sealed and flexible but inextensible lattice work, fabrics, or the like, in order to contain the chemical constituents reacting to form nitric oxide.
In one embodiment, tablets, granules, or other configurations of reactants may be placed in a can, sealed to form the reactor vessel 50 . An aperture 40 in the vessel 50 may receive a tube 52 acting as a reactor outlet 19 . The outlet 19 may conduct nitric oxide generated within the containment vessel 50 to a location outside the insulated container 26 in order to deliver to a line 15 .
Various mechanisms may be available for maintaining the integrity of the apparatus 10 . In one embodiment, a heat shrinkable wrapping material may be formed in a seamless sleeve. The sleeve may be placed around the apparatus 10 , and judiciously penetrated to accommodate the fitting 14 , the vent 18 , the trigger 16 , and so forth. Thereupon, the sleeve 54 may be heated in order to shrink it snugly about the insulated container 26 . Thereafter, any breach of the sleeve 54 indicates a lack of integrity of the apparatus 10 .
One embodiment of an apparatus 10 in accordance with the invention was formed using expanded polystyrene for the insulated container 26 . A fitting 14 to receive a line 15 delivering nitric oxide to a cannula 56 received nitric oxide from a reactor 20 within the insulated container 26 . A vent 18 penetrated the cover 32 of the insulated container 26 to vent steam. A trigger mechanism 16 penetrated the cover 32 in order to reach the piercing assembly 30 described hereinabove.
Containers 28 filled with salt water were provided and placed above the piercing assembly 30 and the reactor 20 therebelow. The heaters 22 were placed entirely below the reactor 20 , although they may also be wrapped therearound, or even placed on top. However, inasmuch as the heaters 22 tend to vaporize some of the liquid in the containers 28 when released, the heated steam generated below the reactor was effective to heat the reactor 20 . Steam rising from heaters thereabove would not ever be in contact with the heaters 22 . That is, heat rising with steam originating above the reactor 20 , will not contribute as much heat to the reactor 20 . The outlet 14 from the reactor was formed of a stainless steel tube 52 penetrating the reactor 20 .
In one embodiment, a method of producing nitric oxide may comprise the following steps. A mixture of reactants may be provided consisting essentially of potassium nitrate, sodium nitrite, and chromic oxide. The chromic oxide may be calcined to remove substantially all water bonded thereto. The reactants may be placed in a vessel, or reactor, and any moisture in the vessel may be substantially evacuated. The reactants in the vessel may be heated to a temperature selected to initiate a reaction generating nitric oxide gas. The nitric oxide gas generated may be drawn from the vessel at negative gauge pressure to substantially preclude further heating and limit further reaction of the nitric oxide gas. The nitric oxide gas may be cooled and mixed with a diluent gas to form a mixture breathable by a subject. The breathable mixture may be regulated to substantially ambient temperature and pressure and delivered to the subject to provide a therapeutically safe and effective concentration of nitric oxide gas.
The blades 40 were positioned between the baseplate 42 , and the cover plate 44 . The guide rod 36 was secured to the baseplate 42 to maintain alignment of the mount 39 as the spring 46 drove the mount 39 forward along the guide rod 36 . Upon release of a trigger 16 , the mount 39 advanced out from under the cover plate 44 , exposing the containers 28 to the sharp blades 40 . The blades 40 compromised the containers 28 from below, thus substantially evacuating all the water therefrom. In the experiment illustrated, salt water was used as the liquid within the containers 28 . In some experiments, a single container was used. In other embodiments, including experiments conducted, multiple containers 28 filled with liquid were used.
Referring to FIG. 31 , in one set of experiments, a single standard heater was used with water, as indicated. In other experiments, multiple heaters 22 were used. In yet other experiments, a single heater was used, but the liquid used to activate the heater 22 , was salt water. The chart illustrates the substantial temperature increase due to the use of the ionized salt within the salt water. Throughout the course of the experiment, the temperature was observably higher, and in some instances substantially higher, when salt water was the electrolyte initiating the reaction in the heaters 22 . Moreover, a single heater provided more temperature rise in the reactor 20 than twice that amount of chemical (two standard heaters), relying only on water alone as the electrolyte.
Referring to FIG. 32 , one may see that the insulation value of the insulated container 26 has some effect. Nevertheless, in general, a more pronounced effect over the latter part of the subject time results from the addition of a second heater 22 .
Referring to FIG. 33 , in another experiment, the drop off over the subject time period is more pronounced in the last half of the time. Meanwhile, the reactor temperature is maintained close to two hundred degrees Fahrenheit for at least about 20 minutes, when two heaters are used.
Referring to FIG. 34 , the volume of nitric oxide produced, cumulatively, over the operation of an apparatus 10 in accordance with the invention provided the illustrated results. In the chart, temperature was maintained for an extremely long period, considering that a therapy session may typically only require about 30 minutes of nitric oxide generation. The chart illustrates that the volumetric rate of nitric oxide generated was substantially constant, giving rise to a substantially straight slope or line in the time period from about 16 minutes to about 100 minutes. Meanwhile, although the measured temperature dropped during that time period from about two hundred degrees Fahrenheit to just over one hundred degrees Fahrenheit, nitric oxide production did not drop off substantially throughout. Nevertheless, the graph illustrates an apparent decline eventually.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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An apparatus for portable delivery of nitric oxide without the need for pressurized tanks, power supplies, or other devices provides a single therapy session by triggering a heater to heat a reaction chamber. A piercing assembly may trigger to open sealed containers, such as bags, of liquid water or salt water in order to activate the heaters. Upon addition of liquid such as water or salt water to a chemically reactive heating element, heat is generated to activate the chemicals generating nitric oxide within a sealed reactor. Upon triggering, liquid containers are unsealed, the liquid drains down to initiate reaction of the heating chemicals, and the heat begins to penetrate the reactor. The reactor, in turn, heats its contents, which react to form nitric oxide expelled by the reactor to a line feeding a cannula for therapy.
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BRIEF SUMMARY OF THE INVENTION
It is the purpose of this invention to provide a roof formed of interlocked panels and panel mounting clips that is structurally sound, economical to install, flexible enough to accommodate differential dimensional changes, and thermally efficient when used with an insulation layer and thermal blocks.
The invention accomplishes this purpose by means of a seamed roof structure composed of substantially identical panels of a design in which opposite sidewalls have flanges shaped to nest together and interlock prior to seaming so that disruptive loads on one panel can be transferred into other interconnected panels thereby remaining the integrity of the panel assembly prior to seaming. The panel interlock is assisted by means of panel mounting clips that also interlock with the sidewall flanges and are fastened to the roof purlins. In preferred form, the mounting clips include a base that is fastened to the purlin and a flexible tab clip that interlocks with the panel sidewalls and is secured to the base in a manner that permits it to move relatively to it in order to accommodate movement of the panels relative to the purlins while maintaining their attachment to them. If roof insulation is desired, blankets of insulation can be laid across the roof purlins and the panels and panel mounting clips laid on top of the insulation. Preferably, the insulation includes relatively stiff thermal blocks that are laid over the blanket insulation directly above the purlins and extend between the panel mounting clips. The panels are laid upon and supported by the thermal blocks thereby allowing the insulative blankets to be substantially fully expanded to their optimum thickness throughout most of their lengths and the entire roof area to be insulated.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified perspective view of a building in the process of construction showing an environment in which a roof structure embodying the invention may be utilized;
FIG. 2 is a broken away perspective view, on an enlarged scale as compared with FIG. 1, showing how roofing panels according to the invention would be installed on the roof of the building of FIG. 1;
FIG. 3 is a broken away perspective view looking down on the top of a roof panel constructed in accordance with the invention;
FIG. 4 is an enlarged cross section along the line 4--4 of FIG. 3;
FIG. 5 is a perspective view similar to FIG. 2 but showing the manner in which adjacent panels are interlocked;
FIG. 6 is a reduced size cross section with parts omitted of adjacent panels in the process of being interlocked, substantially as they appear in FIG. 5, one panel mounting clip being shown in phantom lines to indicate that it is fastened at that position after the panel to which it is to be attached is hinged down to a horizontal position;
FIG. 7 is an enlarged broken away perspective view similar to FIG. 2 showing the panel mounting clip, panel, and purlin;
FIG. 8 is an enlarged cross section through one side of a typical panel with a panel mounting clip attached to it and to a purlin;
FIG. 9 is an enlarged side elevation, broken away, of the panel mounting clip shown in previous Figures;
FIG. 10 is an end elevation of the clip shown in FIG. 9;
FIG. 11 is a cross section through a panel--panel mounting clip--panel joint prior to seaming;
FIG. 12 is a cross section of the joint of FIG. 11 after seaming;
FIG. 13 is a cross section through a panel to panel joint prior to seaming;
FIG. 14 is a cross section through the joint of FIG. 13 after seaming;
FIG. 15 is a perspective view with parts broken away somewhat similar to FIG. 7 but showing a layer of insulation and vapor barrier layer beneath the panel and panel mounting clip;
FIG. 16 is a view similar to FIG. 15 with a thermal block added;
FIG. 17 is a perspective view of the panel clip mounted on a purlin over a layer of insulation and vapor barrier;
FIG. 18 is a perspective view similar to FIG. 2 showing thermal blocks and insulating layer; and
FIG. 19 is a cross section similar to that of FIG. 6 but prior to seaming and on an enlarged scale through one joint of the roof structure with insulating layer and thermal blocks.
DESCRIPTION OF THE INVENTION
FIG. 1 shows a building 1 with a low profile roof structure 3, sidewalls 5, an end 7, and a floor 9. In accordance with the present invention, the roof structure comprises a large number of substantially identical elongated metal panels 11 laid side by side and seamed together so that each side 13 of the roof becomes substantially a one piece membrane formed of a series of integrated panels. The sidewalls 5 are illustrated as consisting of panels 15 erected side by side and seamed together but other sidewall constructions can be used with the roof structure 3 of this invention. It is preferable, however, that the sidewalls be erected prior to the roof structure since, as seen best in FIG. 2, the overhang of previously installed roof panels 11 would interfere with erection of the sidewall panels 15.
The building 1 has any suitable framework, such as arches, formed by the vertical members 17 that support the inclined transverse roof beams 19. The beams 19 support the horizontal longitudinal purlins or rafters 21 of the roof structure. The top surfaces 23 of the upper purlin flanges 25 define roof planes for the roof sections 13 that are plumb and square and they support the roof panels 11 and roof panel mounting clips 27.
In accordance with the invention, the roof panels have a special cross sectional configuration which not only strengthens them but enables adjacent panels to be movably interlocked or hinged and, later, to be tightly joined together in a common mechanical seam. The mechanical interlocks between adjacent panels in conjunction with the clips 27 hold them substantially in place while the remaining panels are being run and until seaming can be finished thereby minimizing the possibility of their disruption due to gusts of wind, etc.
Each panel 11 comprises a central bottom portion 31 which may be flat, as shown, or reinforced in a suitable way such as by a series of transverse embossed ribs (not shown) pressed into it. The panel has opposite sidewalls 33 and 35 extending upwardly and outwardly from the bottom 31 at angles of substantially 60° to the horizontal. The sidewalls 33 and 35 are substantially mirror images of each other, except for top flanges 37 and 39, respectively, and like features are therefore given the same reference numbers. Thus, the sidewalls 33 and 35 include outwardly slanted vertical bottom wall sections 41 having top ends which are joined by horizontal shelf sections 43 to the bottom ends of outwardly slanted, vertical, intermediate wall sections 45. Horizontal rims 47 extend outwardly from the top ends of the wall sections 45 and terminate at the bottom ends of seaming ribs 49 and 51 that form upper panel sections that extend, preferably, at right angles to a plane defined by the bottom wall 31. Ribs 49 are slightly higher than the ribs 51 so that flanges 37 will fit over the tops of flanges 39.
The top flange 37 extends outwardly from the top of its rib 49 at an angle of substantially 60° to it (about 30° to the horizontal or plane of bottom 31); and the top flange 39 extends inwardly from the top of its rib 51 at an angle of substantially 60° to it. The top flange 37 is a little wider than flange 39 and has an inner section 53 that extends outwardly and downwardly at an angle of substantially 60° to its rib 49 (about 30° to the horizontal) and an outer section or lip 55 that extends inwardly and downwardly at an angle of substantially 60° to the inner section 53 and rib 44 (about 30° to the horizontal and 120° included angle) for a distance substantially as indicated by the dimensional relationship shown in the drawings (e.g. FIGS. 4 and 11-14) so that a part of it will be vertically below a flange 39 after installation. The top flange 39 has an inner section 57 that extends inwardly and downwardly toward bottom 31 at an angle of substantially 60° to its rib 51 (about 30° to the horizontal) and an end section 59 that is doubled back toward rib 51 to form a reversely bent bulb-like end edge portion for the flange 39. It will be noted that suitable radii are provided at the various corners and bends and that the panels 11 are of a shape that can be roll formed from sheet metal in accordance with known methods and using roll stand equipment that is commercially available.
Referring to the panel mounting clip 27, best illustrated in FIGS. 7-10, the construction of this member enables it to assist in holding the panels 11 in place after they are laid. It includes means to permit the panels to expand and contract relative to the purlins 21 in response to temperature differentials and changes during the life of the roof thereby minimizing temperature induced roof stressing. The panel mounting clip 27 is preferably formed of sheet metal and has a channel shaped base member 63 with a lower horizontal flange 65 that has a pair of openings 67 in it whereby the clip may receive screw fasteners or the like 69 for attaching its bottom flange 65 to the top flange 25 of a purlin 21. The member 63 has a vertical web 71 and several gussets 73 may be pressed in it and in the bottom flange 65 at the corner between the web 71 and the flange 65 to provide rigidity to the bottom end of the clip 27. The top flange of the base member 63 has a central section 75 which is parallel to the bottom flange 65 but which is bent to extend in the opposite direction. On either side of the top flange 75 at the opposite ends of the member 63 are a pair of top end flanges 77 which extend in the same direction as the bottom flange 65 and are parallel to it. The flanges 75 and 77 provide shelves which fit beneath the rims 47 of the panels 11 to provide means on which they may be supported if their weight is not carried directly by the purlins.
The web 77 has a horizontal slot 79 extending through it which is substantially coextensive with the flange 75. A flap-like tab clip 81 is mounted on the web 71 in the slot 79 and is capable of sliding movement from one end of the slot to the other. Tab clip 81 is preferably formed of thinner metal than is the base member 63 and is somewhat resilient so that its vertical web portion 83 is biased toward the surface of web 71 but can also move transversely away from it in the direction of the arrow 85 (see FIG. 10). The bottom of the tab clip has a special resilient loop configuration which includes a reverse bend portion 87 that extends upwardly after passing through the slot 79 and is shaped to press against the back of the web 71 just as the bottom of the web 83 presses against the front side of web 71. The clip metal is reversely bent downwardly in a section 89 that extends to below the bottom of the slot 79 for a distance substantially equal to the length of the reverse bend section 87. The section 89 is then reversely bent into a section 91 corresponding to section 87 which engages the back side of the web 71 and extends through the bottom side of the slot 79 where it is reversely bent downwardly in an end section 93 for the tab clip 81 that engages the inside face of the web 71. The reverse bend sections 87 and 91 together with the section 89 form a resilient loop-like holding means 95 for the tab which clamps it to opposite sides of the web 71 but permits it to slide in the slot 79 between flanges 77. The horizontal spacing of the back section 89 from the reverse bends 87 and 91 provides a spring action that tends to hold the tab clip 81 in a vertical position as shown in FIGS. 8 and 10 but also enables it to be moved away from the web 71 in the direction of the arrow 85. Since the tab clip 81 is relatively thin it can also be bent resiliently to some extent in the direction of the arrow 97.
While the tab clip 81 is capable of longitudinal movement with respect to the base member 63 it does have a center position along the midline of the member 27 and is yieldably held in this position by means of a dimple 99 that is embossed in the web 71 and adapted to seat in a hole 101 formed in the tab web 83. Substantial force tending to move the clip 81 in one direction or another along the slot 79 will overcome the spring pressure of the holding section 95 and enable the web 83 to ride over the dimple 99.
The top end of the tab clip 81 has a hook-like flange 103 which is very similar to panel flange 37. Thus, it has a section 105 that extends outwardly and downwardly at an angle of substantially 60° to the section 81 and ends in a lip flange 107. The height of the flange 103 above the plane of the top surfaces of flanges 75 and 77 is a little more than that of a flange 39 above a rim 47. The transverse length of the flange 103 is also a little more than that of flange 39. The flange dimensional relationships enable flanges 103 to snugly fit over and hook on to flanges 39 and the panel flanges 37 to fit over, hinge around, and hook on to the combined flanges 39 and 103 (FIGS. 11-12) as well as single flanges 39 (FIGS. 13 and 14).
Referring to FIGS. 15-19, the structure already described is insulated. This is done by use of a layer 121 of compressible blanket insulation beneath the panels 11 and a plurality of thermal blocks 123 that are substantially incompressible and located over the purlin runs. In FIGS. 15-17 a vapor barrier sheet 125 is shown beneath the blanket insulation 121. As will become apparent, in using insulation the panel clips 27' are modified slightly so that the distance between the slot 79' and flange 65' is increased over that used with previous clip 27. This is required to accommodate substantially the thickness of thermal bars 123. Other than this change (and tangs 126) the structures are substantially the same as previously described and, accordingly, the same reference numbers are used.
It will be understood that layers of blanket insulation 121 from rolls are simply laid across the tops of the purlins 21 before installation of the panels 11. The panel mounting clip 27' may be placed over insulating layer and fastened to a purlin 21 by extending fasteners 69 through the openings 67' in the bottom flange 65' and then through the insulation into the purlin 21 as seen in FIG. 19 and as assumed in FIGS. 15 and 16. When attached to the purlin 21, the tab clips 81' of mounting clips 27' can hold the panels 11 in place over the insulating layer 121.
Preferably, the thermal blocks 123 have a width on their bottom faces which is about the same as the width of the purlin surface 23. They are laid on top of the insulation over the purlins to extend between pairs of panel clips 27'. The panel clips may have triangular tangs 126 bent out at right angles from webs 71' to penetrate into a butt end of each block and help to mechanically hold them in place until the panels 11 are laid on top of them. The side faces of the thermal bars 123 are preferably tapered on an angle of about 45°, as seen at 127, to facilitate expansion of the insulative material in the blanket 121 to its full thickness. The thermal bars 123 may be formed of suitable material having strength as well as insulative properties, such as urethane foam or high density styrofoam. As seen in FIG. 19, the ends of the bars 123 are notched out at 129 so that they can fit over the heads of the bolts 69 and thereby extend closely adjacent to the webs 71' of the panel mounting clips 27'.
When the panels 11 are laid and held in place by the panel mounting clips 27' the bottoms 31 thereof will rest on the tops of the bars 123. Thus, their weight is transmitted through the bars 123 and through the blanket insulation into the purlins 21 thereby compressing the insulation to a small fraction of its normal thickness, as seen at 131. Because of the beveled side faces 127, the blanket insulation is quick to rebound to its maximum thickness and this feature plus the insulative quality of the thermal bars 123 provide a substantially continuous and efficient insulative layer over the entire surface of the roof section 13 to which the insulation is applied.
Since the bottom 31 of each panel is prevented from contacting the top surface 23 of the purlin by the thickness of the thermal bars 23 and the insulation section 131 but the panel clip 27' is only separated from the surface 23 by the insulation section 131, it is necessary to increase the height of the web 71' as compared with the panel clip 27 and its web 71. This is apparent upon consideration of FIG. 19. This figure also shows that in other respects the structure of the insulated roof revealed in FIGS. 15-19 is substantially the same as the uninsulated roof of FIGS. 1-8.
In practical application of the invention, the framework of the building 1 is first erected followed by the side walls 5. After this is done, the panels 11 may be laid on the purlins 21 starting from the left and moving toward the right end of the roof section 13. Ignoring special procedures known to those in the art for handling the structure at the ends of the roof section, a panel 11 is laid across the purlins 21 and may be allowed to rest there (or on insulation 121) under the force of gravity and resistance of friction. If desired, a simple screw or two (not shown) may be passed through the bottom 31 and threaded into a purlin flange 25 to provide a means for temporarily holding the panel in place until the panel mounting clips 27 are installed. After a panel 11 is thus laid on the purlins 21, the panel mounting clips 27 are lined up with the right side wall 35 of the panel so that the flanges 75 fit under the rim 47, the tab clip 81 abuts the upper section 51, and the top flange 103 and hook lip 107 extend over and around the flange 39 on the side wall 35. The actual connection can be made by hooking the flange 103 (or 103') on the flange 39 and hinging the clip 27 around to the vertical position indicated. When this is done, holes are drilled in the purlin flange 25 in alignment with the holes 67 in the bottom flange 65 of the panel clip 27. Screws 69 are then threaded into these holes in the purlin to thereby firmly anchor the panel clips to the purlin. This, of course, also anchors the side wall 35 of the panel 11 to the purlin so that it cannot move upwardly away from it.
As seen best in FIGS. 5 and 6, the next step in the assembly procedure is to attach another panel 11 in side by side relationship to the panel that has just been anchored in place by panel mounting clips 27. This is done by interconnecting the side wall 33 of the second panel to the side wall 35 of the first and anchored panel. More particularly, it is done by placing the flange 37 over and around the flange 39 so that the stationary flange 39 is nested inside of the flange 37. This interconnection is accomplished by tilting the panel 11 that is being attached at an angle to the horizontal so that the lip edge 55 can fit in the corner of the flange 39 as shown by the phantom lines in FIG. 13. When this relationship has been accomplished between the flange 37 and the flange 39, the panel 11 can be hinged in a clockwise manner until its bottom 31 comes to rest against the surfaces 23 on the purlins 21 or against the thermal bars 123. At this point the relationship between the flanges 37 and 39 will be substantially as shown in full lines in FIG. 13 in the cross sections where there is no panel clip 27 and substantially as shown in FIG. 11 where there is a panel mounting clip 27. It will be seen that the lip 55 on the flange 37 lies vertically below the rebent end 59 of the flange 37 and consequently the two panels are interconnected in such a way that it is quite difficult to separate them by simple movements of one relative to the other such as might be caused by wind gusts, etc. It is unlikely that the second panel 11 will be disconnected or separated from the anchored panel 11 prior to seaming of the joint between them unless there is also angular unhinging movement of it to unhook its flange 37 from the mating flange 39.
After the second panel 11 has been hooked to and hinged around the anchored panel as just described, panel mounting clips 27 are hooked to its side wall 35 and secured in place by bolts 69 as already described for the first panel. This process of hooking a panel being added to the roof section to one already anchored on the roof section, hinging it down until it rests on the purlins 21, fastened the panel mounting clips 27 to the side wall 35 of the panel and then to the purlin 21, is repeated until all the panels 11 that it is desired to install are in place. It will be noted that in this condition the panel mounting clips 27 together with the loose hook type interlock between flange pairs 37 and 39 will integrate the panels so that they in fact form a unitary though flexible roof structure 13. This flexibility is then materially reduced by running a suitable seaming tool along the upright upper vertical rib sections 49 and 51 to bend the flanges 37 and 39 against the inside face of upper section 51 on side wall 35 to achieve the compressed, interlocked final assembly shown in FIGS. 12 and 14. When this is done the lip 107 of the panel mounting clip tab 81 may in some structures be flattened out, as seen by comparing FIGS. 11 and 12, but this has no undesirable effect since it is apparent that the clip 27 still serves to resist movement of the joint in an upward direction away from the purlins 21. It does have a beneficial effect in that it makes it somewhat easier for the tab 81 to move longitudinally relative to the upper sections 49 and 51 of adjacent panels. Such relative movement is, as previously mentioned, accommodated by the slot 79, the spacing between flanges 77, the dimple 99, and the flexible holding means 95 of the panel clip construction 27 and permits differential force systems introduced by temperature changes, pressure changes, etc. between interconnected panels to dissipate themselves in relative movement of the panels rather than in deformation or buckling of the panels. The resiliency of the tabs 81 also permits the interconnected panels 11 to have flexibility as a roof membrane relative to the purlins 21 and structure 17.
While not illustrated, it will be understood that suitable sealant or mastic material, strips or tape can be applied as needed to weatherproof the roof structure.
Thus, the invention provides an improved roof construction that is sound of structure, economical to install, flexible enough to dissipate differential stress systems, and thermally efficient when combined with blanket insulation and thermal blocks.
Predictable, long term thermal characteristics and a minimal heating/cooling load are advantages of the insulated roof structure. Also advantageous is the flexibility provided by the panel mounting clip and panel interlock combination which enables the parts to have some freedom of movement in either direction permitting the roof to respond to seasonal changes and heat or cold by shifting, expanding, or contracting but in a way that tends to keep roof stressing below critical limits to provide a longer roof life. Modifications in the specific features shown and described may be made without departing from the spirit and scope of the invention.
Copending applications Ser. No. 875,532 and 875,533, filed of even date herewith by the present applicant are directed to the metal panel members 11 and the panel clips 27.
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A roof structure and its components comprises a series of metal panels having flanges that interlock when the panels are laid side by side and which are subsequently tightly seamed together to convert the individual panels into an integrated roof forming membrane. The roof structure may be insulated through the use of a blanket vapor barrier and insulation under the panels preferably along with thermal blocks located over the purlins. The roof structure includes unique flexible panel mounting clips that attach the panels to the purlins in such a way as to permit the panels to expand or contract in response to temperature and pressure changes, thereby minimizing roof stressing.
The questions raised in reexamination request No. 90/000,342, filed 03/16/83, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e).
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BACKGROUND OF THE INVENTION
The present invention relates to an auxiliary package for a bath-pool, and particularly to an improved auxiliary package used for a sauna bath-pool which is capable of circulating, heating and filtering the water of the bath-pool.
As shown in FIGS. 10 and 11, there are two types of known auxiliary packages used for sauna bath-pools. As shown in FIG. 10, one of the known auxiliary packages 200 mainly comprises a motor 201, a water pump 202 driven by motor 201, a heating device 203, and a filter 204. All of these devices are mounted on a base 215 and are connected to each other by pipes 206, 207, 209, 211, elbows 208, 210 and valve 212. The water pump 202 comprises a water inlet 205, connected to the drain pipe (not shown) of a sauna bath-pool, which can suck the water from the sauna bath-pool. The water outlet 213 is used to return the water after it has been heated and filtered by heating device 203 and filter 204 respectively to the sauna bath-pool. The auxiliary package shown in FIG. 11 is substantially the same as that shown in FIG. 10 except that the filter 204 is connected parallel to the main pipe of the package and further includes a coil pipe 221 adjacently mounted around the outside of the motor 201 so that a portion of water from the sauna bath-pool can be returned to the sauna bath without being filtered while a portion of the water can be first filtered by filter 204, heated by passing through the coil pipe 221, and then returned to the pipe 207 so as to be preheated and filtered.
There is a common disadvantage to both of these two types of auxiliary packages as described above, namely, the pumps, the heating devices and filter devices must be connected by pipes and pipe fittings and must be supported on a base. Accordingly, the whole auxiliary package cannot be constructed in a compact way and therefore these known auxiliary packages for sauna bath-pool are not economical and convenient for use.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved auxiliary package for a bath-pool which can be easily set up, and be constructed in a compact way.
To attain the above-mentioned object, the auxiliary package for bath-pool of the present invention comprises: a housing having a water inlet for receiving water from the bath-pool, a water outlet connected to the bath-pool and a plurality of partition walls for dividing the interior of the housing into a plurality of chambers and forming a water passage therein, a water pump mounted in one of the chambers for sucking the water from the inlet and circulating the water through the passage to the bath-pool, an electric motor mounted in one of the chambers for driving said water pump, which is capable of transfering the heat generated to the water flowing in the passage, a control box for controlling the activation of the electric motor, which is mounted watertight on the housing, a filter detachably mounted in one of the chambers housing, which is located in the downstream of the water passage to filter at least a portion of the water flowing in the water passage, heating means mounted in the water passage for heating the water flowing in the water passage, temperature adjusting means for adjusting the temperature of the water flowing in the water passage, and a temperature-limit switch to prevent the temperature of the water from exceeding a predetermined range.
In an alternate embodiment of the auxiliary package for bath-pool of the present invention, the electric motor comprises a body, a heat transfer sleeve mounted around the body of the motor and a heat exchanging plate mounted watertight between the body and the water passage and connected with at least a portion of the heat transfer sleeve so as to transfer the heat generated by the motor to the water through the heat transfer sleeve and heat exchanging plate.
In another embodiment of the auxiliary package for bath-pool of the present invention, the electric motor comprises a body, a set of pipes adjacently mounted around the body and connected upstream of the water passage so as to transfer the heat generated by said motor to the water.
In another embodiment of the auxiliary package for bath-pool of the present invention, the electric motor is a submersible motor submersed in the water passage so as to transfer the heat generated by the motor into the water.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reference to the following detailed description and accompanying drawings, which form an integral part of this application:
FIG. 1A is a longitudinal sectional view of the auxiliary package for a sauna bath-pool of a first embodiment of the present invention.
FIG. 1B is a side view, partly in section, of the auxiliary package for a sauna bath-pool as shown in FIG. 1A.
FIG. 1C is an enlarged view of a segment of FIG. 1A showing how the motor housing and the housing of the auxiliary package is connected in watertight manner.
FIG. 1D is a enlarged top view of the supporting, fixing structure of the filter as shown in FIG. 1A.
FIG. 1E is a sectional view, of the electrical heating device, taken along line E--E of FIG. 1B.
FIG. 2 is a longitudinal sectional view of the auxiliary package for a sauna bath-pool of a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of the auxiliary package for a sauna bath-pool of a third embodiment of the present invention.
FIG. 4 is a longitudinal sectional view of the auxiliary package for a sauna bath-pool of a fourth embodiment of the present invention.
FIG. 5 is a sectional view of a segment showing the leakage prevention, air cooling and supporting mechanism of the motor of the auxiliary package for a sauna bath-pool of the present invention.
FIG. 5A is a sectional view of the air cooling means used in FIG. 5.
FIG. 6 is a schematic view showing a first embodiment of the auxiliary package of the present invention mounted to a sauna bath-pool.
FIG. 7 is a schematic view showing a second embodiment of the auxiliary package of the present invention mounted to a sauna bath-pool.
FIG. 8 is a schematic view showing a third embodiment of the auxiliary package of the present invention mounted to a sauna bath-pool.
FIG. 9 is a schematic view showing a fourth embodiment of the auxiliary package of the present invention mounted to a sauna bath-pool.
FIG. 10 is a schematic view of the first of the known auxiliary packages for sauna bath-pool.
FIG. 11 is a schematic view of the second of the known auxiliary packages for sauna bath-pool.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The detailed structure of the first embodiment of the present invention will be hereinafter described based on FIGS. 1A, 1B, 1C, 1D, and 1E. The auxiliary package for a sauna bath-pool of this embodiment mainly comprises a housing 1, a filter support 9, a filter 10, an electrical heating device 16, a water pump 22, a filter cover 11, a motor 30, a heat transfer plate 32, a motor housing 33 and a control box 50. Housing 1 is integrally formed by injection molding of thermal plastic material. The filter support 9 is detachably supported in housing 1. As shown in FIG. 1D, two protrusions 9A are provided at the outer periphery of the support 9 for insertion into two corresponding concave portions (not shown) formed in the side wall of the housing 1 to receive support 9 in housing 1. Further, two handles 9B are provided on the inner side wall of support 9 to enable the user to easily remove or place the filter 10 into the filter support 9 by grasping the two handles 9B, 9B.
The interior of the housing 1 is divided into a heating chamber 2, a water pump chamber 3 and a filter chamber 4. In the side wall of the heating chamber 2 there is a water inlet 8, and in the heating chamber 2 itself, an electrical heating device 16 and a temperature detecting tube 16A also is provided. As shown in FIG. 1E, the control box 50 can be integrally formed with the housing 1 and divided therebetween by a partition wall. A portion of the temperature sensing tube 16A and the electrical heating device 16 is jointed together by a soldered portion 16B so as to directly and precisely sense the water temperature to prevent over heating. The electrical heating device 16 and the temperature sensing tube 16A are supported and fixed in housing 1 by frame 16C. Frame 16C is made of heat insulating material such as ceramics. The partition wall 50A is provided with an opening 50B through which the electrical heating device 16 and the temperature sensing tube 16A are passed. Furthermore, the control box 50 side of the partition wall 50A is also provided with a metal plate 50C which is mounted watertight on opening 50B to prevent passage of water. Metal plate 50C also functions as a support to fix the electrical heating device 16 and the heat sensing tube 16A, and also as a current collecting device for detecting ground faults. The water pump 22 is mounted in water pump chamber 3. The filter 10 is mounted in filter chamber 4 with its bottom supported on the filter seat 9. The top of the housing 1 is detachably closed by the filter cover 11, for example by screws. The central portion of the filter cover 11 is extended upward to form a tube-shaped water outlet 13, and extended downward to the top of the filter 4 to form a suppressing portion 12 to suppress the top of the filter 10 and fix the filter 10. The top of the water outlet 13 is connected to a check valve 14. The side wall of of filter chamber 4 is provided with a drain valve 15. To enable circulation of water from the sauna bath-pool, for heat transfer and parallel filtering (this type of filtering can reduce the load of the motor so as to enhance the life of the motor), at the partition walls of each chambers, the side wall of the suppress portion 12 and the bottom of the filter 9 are respectively provided with communicating openings 17, 18, 19 and 20. In this embodiment, the motor 30 for driving the water pump 22 is partitioned watertight by the heat transfer plate 32 from the water passage. In other words, motor 30 does not come into direct contact directly with the water. In order for the heat generated by the motor 30 to be transfered to the water, a heat transfer sleeve 31, which is integratedly formed with the heat transfer plate 32, is provided at the outer periphery of the motor 30. Both the heat transfer plate 31 and the heat transfer sleeve 32 are made of metal. A motor housing 33 is provided at the outside of the motor 30 for insulating heat, electricity and also for the protection of the motor 30. Heat transfer plate 32, motor housing 33 and housing 1 are fixed together by a fixing bolt 24. As shown in FIG. 1C, between the housing 1 and the heat transfer plate 32, as well as the heat transfer plate 32 and the motor housing 33 are respectively provided with a packing material so as to make them watertight. This packing material preferably is made of flexible material such as rubber. As shown in FIG. 1A, the outer periphery of the motor housing 33 is provided with a handle 34 so that it may be carried by the users. The bottom of motor housing 33 is provided with a base 37 to support the whole auxiliary package. In addition, some fastening means (not shown) are also provided at appropriate locations of housing 1 so as to fasten the whole auxiliary package to sauna bath-pools.
Referring to FIG. 5, motor shaft 30B is supported in the hub 38 which is located in the center of the heat transfer plate 32. To prevent the water flowing through the housing from permeating to the motor, between the central hole of the heat transfer plate 32 and the motor shaft 30B there are three sealing components 40A, 40B and 40C, which are preferably made of rubber material, to prevent the water from permeating from the left side of the heat transfer plate 32 to the right side. If desired, a spring 40D can be provided to press these water sealing components, for example 40A, to be retained tightly close to the motor shaft 30B and enforce the watertight effect. Between the bearing 39 and the sealing component 40C, an air cooling means 37 is provided for cooling the motor shaft 30B. The structure of this air cooling means 37 is shown in FIG. 5A. As shown in FIG. 5 and FIG. 5A, this air cooling means 37 comprises a cylindrical housing 37A having an eccentrical hole 37B therein, a rotor 37C mounted in the eccentrical hole 37B and on the motor shaft 30B, which is capable of rotating with the motor shaft 30B, an air tube 37D communicating the hole 37B to open air and a drain hole 38A. When the motor shaft 30B is rotated, air is sucked from the air tube 37D, compressed by the rotor 37C, and expelled out from the drain hole 38A so as to cool the motor shaft 30B. The drain hole 38A not only functions as a passage for the draining out of the cooling air but also functions as a passage for draining out of any small amount of water permeated into the water sealing components to prevent any water from permeating into the motor 30. Bearing 39 is water proof only on one side, namely, on the water pump 22 side. In addition, around the enlarged portion of the motor shaft 39A on the bearing 39 side, an O ring 41 is provided so that water permeated into the O ring 41 may be discharged out along the radial direction of the motor shaft 39A. As shown in FIG. 1A an O ring 36 is also provided between the motor housing 33 and the heat transfer sleeve 31 so as to prevent any water in the gap between the motor housing 33 and heat transfer sleeve 31A from permeating into the motor 30. Further, as shown in FIG. 1A, the motor housing 33 is designed to be in an inclined position so as to make the small amount of water that flows into the motor housing 33 to drain to the lower zone in the motor housing 33. The lower zone is also provided with a drain hole 44 and a leakage detecting device 43. The water leakage detecting device 43 is capable of switching off the power when water leakage is detected.
The control box 50 is provided with a pressure operated switch 52, temperature regulator 53, various power switches, various temperature limit switches and indicating lamps (not shown). The pressure operated switch 53 can automatically cut off the power of the electrical heating device 16 when the water pressure in the housing 1 is lower than an indicated value. The temperature limit switch can automatically cut off the power of the heating device 16 when the water temperature is higher than a predetermined level. The sealing cover 51 is provided watertight on the control box 50 and can be opened for maintenance.
For safety purpose, microswitches are provided at all the locations where open-and-shut devices are mounted, for example, at the sealing cover 51 of the control box, at the sealing cover 11 of the filter and at the heat transfer plate 32. In addition, each of the sockets (not shown) of the auxiliary package for bath pools is provided with a relay (not shown) and a control line is connected to each relay so as to automatically turn off the power of each socket when each of the above open-and-shut devices is opened. Furthermore, each relay is provided with a reset switch for resetting the electrical power.
Referring again to FIG. 1A, the flowing, heating and filtering of the water from the sauna bath-pool will be described. The water from the sauna bath-pool flows first into the heating chamber 2 along the arrow A and is heated by the electrical heating device 16, the water is then sucked into the water pump chamber 3 through communicating opening 17 along the arrow B direction and then is forced by the pump 3 to the filter 4 along the arrow C direction through 18. Meanwhile, a portion of the water is forced through the hollow suppressing portion 12 through the communicating opening 18 and the water outlet 13 to the sauna bath-pool along the arrow D direction. Another portion of the water is forced to flow through the filter material of filter 10 along the arrow E direction and is filtered: then it is forced to the heating chamber 2 through communicating opening 20 and is mixed with high velocity, low pressure water which comes from the water inlet 8 and flows into the heating chamber 2 along the arrow A direction, so that the filtered water is easily sucked into the water pump chamber 3. In this way, overload of the motor due to the filtering can be reduced but the suction momentum will not be decreased to influence the jet flow injected into the sauna bath-pool. Preferably, the communicating opening 20 between the filter 4 and the heating 2 is provided with an open-type spring check valve.
When it is desired to drain out the water in the sauna bath-pool for cleaning, the user can close the check valve 14 (as shown in FIG. 1A), open the drain valve 15 and connect a drainage pipe so as to continuously suck out the water in the sauna bath-pool and drain it out.
The structure and function of the second embodiment of the present invention will now be described by referring to FIG. 2. In this second embodiment, the difference of the structure from the first embodiment is that the motor is totally submersed into the water so that the heat generated by the motor can be directly used to heat the water. It is necessary in this embodiment to use a submersible motor. The integrally formed housing 60 is divided into a motor chamber 61, a filter chamber 62, a heating chamber 63, a motor 83, a water pump 84, a filter 87 and an electrical heating device 88 which are respectively provided within each chamber. A communicating opening 69 is provided between the motor chamber 61 and the filter chamber 62, and the filter chamber 62 and heating chamber 63 have communicating openings 70 and 72. Each opening of motor chamber 61, filter chamber 62 and heating chamber 63 is respectively provided with doors 75, 76 and 77 to close the openings in an openable and watertight manner. In addition, the same as that in the first embodiment, each of the doors are provided with microswitches 21. The purpose of these microswitches is the same as in the first embodiment. The doors 75 and 77 are provided with a water inlet 78 and a water outlet 79. The water is introduced into the motor chamber 63 from the water inlet 78 along the arrow direction, to perform direct heat exchange with the motor 83, the water is then introduced into the filter chamber 62 from communicating opening 69 where a portion of the water is directly introduced into the heating chamber 63 without being filtered and a portion of water first introduced into the filter chamber 87 where it is filtered and then is introduced into the heating chamber 63 from the communicating chamber 72. After the water is heated by the electrical heating device 88 in the heating chamber, it is introduced into the sauna bath-pool via the water outlet 79 to complete the circulation, filtering and heating of the water from the sauna bath-pool.
The structure and function of the third embodiment of the present invention as shown in FIG. 3 will now be described. The structure of the third embodiment is substantially the same as that of the second embodiment except that the water introduced into the housing 90 from the water inlet 91 is first subjected to direct heat transfer with the motor 93 submersed in the water passage. The water then is filtered by filter 95 and finally is introduced to the sauna bath-pool via water outlet 92 to complete the water circulation, heating and filtering of the water.
Next, the structure and function of the fourth embodiment of the present invention will be described. The structure of this embodiment is the same as the second embodiment except for the type of heat exchanging and filtering. In the second embodiment, all of the water is through the outer periphery of the motor and flows subjected to direct heat exchange, and only a portion of the water is subjected to filtering. However, in the fourth embodiment, only a portion of the water flows through the pipes mounted on the periphery of the motor and is subjected to heat exchange, the other portion of water is not subjected to heat exchange and is mixed with the portion of water heat exchanged later. All of the water used is first filtered and then is heated. As shown in FIG. 4, the housing 100 of the auxiliary package for bath-pools of this embodiment is integrally formed and is divided into a motor chamber 101, a passage chamber 102, a filter chamber 103, and a heating chamber 104. A motor 105 and a water pump 107 driven by the motor 105 are mounted in this motor chamber 101. The water pump 107 comprises a water inlet 108 and water exit 109. A conduit 110 is extended from the passage chamber 102. The conduit is connected watertight to the outlet 109 of the water pump 107. The heat exchange pipe 113 wound around the body of the motor 105 is formed by two long strips overlaped, and connected together with their two sides so that a water passage 115 is formed therebetween. These two strips are made of flexible and impermeable material. The inlet and outlet of the heat exchange pipe 113 are respectively connected to the inlet 108 of water pump 107 and passage chamber 102 by two connecting pipes 116', 117'. A filter 116 is mounted in the filter chamber 103 and an electrical heating device 117 is mounted in the heating chamber 104. In addition, at one end of the motor chamber 101, filter chamber 103 and heating chamber 104 may be opened and respectively closed with a sealing cover 118, 119 and 120. The sealing covers 118 and 120 are respectively mounted with a water inlet 121 and a water outlet 122 so as to communicate with the sauna bath-pool (not shown). The water inlet 121 is aligned with the inlet 108 of the water pump 107. When the auxiliary package of this embodiment is used, the water to be treated flows along the arrow direction in FIG. 4. That is, after the water is introduced into the inlet 108 of the water pump 107 through water exit 121, a portion of the water is directly sucked into the passage chamber 108 by the pump 107 without being subjected to heat exchange. Another portion of the water introduced to the heat exchange pipe 113 through connecting pipe 116, then is introduced around the outer periphery of the motor 105 via passage 115 along the arrow direction so as to be subjected to heat exchange. Finally, the water flows through connecting pipe 117 to meet with the water in the passage chamber 102. The heat exchange between the water and the motor is the same as that in the first embodiment as shown in FIG. 1A, which utilizes pressure difference to attain the effect of reduction of the load of the motor and utilizes this kind of heat exchange to cool the motor and preheat the water. Thereafter, the water is introduced into the filter 116 to be filtered and then is introduced to the electrical heating device 117 to be heated. The water, then is forced out from the water outlet 122 and returned to the sauna bath-pool to complete the circulation, partial heat exchange, filtering and heating.
FIGS. 6 to 9 show how the auxiliary package for bath-pool of the present invention is mounted or connected to the sauna bath-pool.
In FIG. 6, the auxiliary package P of the present invention is mounted in the hollow side wall 141 of a sauna bath-pool 140. Its inlet pipe I and the outlet pipe J are respectively connected to the pipe 143 and pipe 144 mounted around the water tank 142. The water is sucked from a plurality of suction openings 145 which are connected to the pipe 143, and is jeted into the sauna bath-pool 140 from a plurality of nozzles 146 connected to the pipe 144.
In FIG. 7, the auxiliary package P of the present invention is mounted on the side walls of a sauna bath-pool 150. This sauna bath-pool comprises a wall body made of flexible, water-impermeable material and a bottom formed as a rigid frame. The water inlet I and water exit J are extended into the interior of the sauna bath-pool by mounting over the top of the side wall 151 of the sauna bath-pool and are fixed on the side wall by a dome-shaped clamp 152.
In FIG. 8, the auxiliary package P of the present invention is mounted on the side wall of the sauna bath-pool. The inlet pipe I and outlet pipe J are connected into the bottom of the sauna bath-pool 160. The water is sucked by a plurality of suction openings 161 and is injected back to the sauna bath-pool by a plurality of nozzles 162.
In FIG. 9, the auxiliary package P of the present invention is mounted on the side wall of a sauna bath-pool made of rigid material. The inlet pipe I and outlet pipe J are respectively connected with the pipe 171 and pipe 172 mounted around the side wall of the sauna bath-pool. The water is sucked by a plurality of suction openings 173 and are injected to the sauna bath-pool by a plurality of nozzles 174.
In all of the mounting types of the auxiliary package of the present invention, the nozzles can be designed to be capable of injecting the water together with air so as to attain a massaging effect. Since the structure of the nozzles is outside the scope of the present invention, its detailed structure is not described.
In accordance with the present invention, instead of utilizing pipes, fittings, and elbows to connect the water pump, electrical heating device and filter, an integral formed housing is used to receive all the components therein. Therefore, it is not necessary to use a base so that the package of the present invention can be made in a compact form. In addition, by using the heat generated by the motor to heat the water, the energy can be greatly saved and the life of the motor used can be lengthened. Furthermore, as all of the sealing covers of the water pump, electrical heating device and filter are provided with a microswitch and all of the power sockets are provided with a breaker, when the sealing covers are opened or when an electricity leakage occurs, the power can be automatically switched off. In addition, between the motor and water pump a water proof mechanism is provided so that electricity leakages can be completely prevented.
While the invention has been described in terms of several preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims.
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An auxiliary package for a bath-pool, particularly for a sauna bath-pool, comprising a housing having a water inlet for receiving water from the bath-pool, a water exit for sending the water back to the bath-pool and a plurality of partition walls for dividing the interior of the housing into a plurality of chambers and forming a water passage therein, a water pump mounted in one of the chambers for sucking the water from the inlet and circulating the water through the passage to the bath-pool, an electric motor mounted in one of the chambers for driving the water pump capable of transfering the heat generated to the water flowing in the passage, a control box for controlling the electric motor, which is mounted watertight on the housing, and electric plug means adapted for connection to a power system for receiving electrical power. As the water pump, the motor and the filter of the package are all mounted in a housing, the auxiliary package of the present invention can be made more compact than prior known auxiliary packages for sauna bath-pools. Another advantage of the auxiliary package of the present invention is that the heat generated by the motor can be used to preheat the water from the sauna bath-pool to save energy. Furthermore, the water pump, motor and filter are provided with sealing covers so as to make them watertight, and each sealing cover also is provided with a microswitch to cut off the power when any of the sealing covers is opened.
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TECHNICAL FIELD
[0001] This invention relates generally to pipe thread applicator devices, and in particular to an improved applicator for applying a pipe dope sealing material to the threads of a pipe.
BACKGROUND
[0002] Pipe dope, or pipe joint compound, is a gooey compound used to seal the connection between threaded pipes and fittings. Because the threads in pipes and fittings still leave an air gap between the two surfaces, the gap must be filled to make it water tight (or gas tight for gas lines).
[0003] Pipe dope has been around for a very long time and tends to be the favorite product for professional plumbers. Also, pipe dope should not be used on plastic threads, unless the container identifies it as safe for use on plastic pipe. Pipe dope is non-hardening and works as both a sealant and a lubricant. This is useful for unthreading pipes if the need arises and so gives it some advantage for that reason. However, because it is a lubricant, it can allow for over-tightening of plastic pipe which can lead to cracking and breakage. In practice, to apply pipe dope, the pipe dope is usually just applied as a coat onto the threads of a male thread set using the brush applicator supplied with the container in which the dope is sold. It is important to make sure all the threads are covered and avoid applying dope over the end or inside the pipe. If the pipe dope is not applied in the right amount and evenly, the joint may not be sealed properly when the male threads of the pipe are tightened into a female threaded fitting.
[0004] Improved pipe dope applicators, for example those shown in U.S. Pat. Nos. 5,743,667; 5,222,821; 4,932,801 (all to Osborne and all incorporated herein by reference in their entirety) and other various prior art methods and structures have been used to apply thread sealing liquids to pipes. Some of these pipe dope applicators are more effective or fool proof than others. Some are more effective yet are more costly to manufacture than others.
[0005] Accordingly, there is need for an economical, yet fool-proof, dope pipe applicator that is not subject to human error when it is used to apply pipe dope to the threads of the end of a pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The above needs are at least partially met through provision of the method and apparatus described in the following detailed description, particularly when studied in conjunction with the drawings, wherein:
[0007] FIG. 1 is a perspective view of a pipe dope applicator connected to a typical receptacle/container in which such product is commercially sold except the original cap of the receptacle has been replaced by a preferred embodiment of the present invention;
[0008] FIG. 2 is a cross sectional view of the preferred embodiment of FIG. 1 and shown with a pipe having threads shown before the invention is being used to apply pipe thread dope to the threads; and
[0009] FIG. 3 is a cross sectional view, like FIG. 2 , but showing the pipe in dashed lines having been pushed into the inner portion of a pipe dope metering cup and showing how the pipe dope is forced through the metering apertures to coat the threads of the pipe;
[0010] Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.
DETAILED DESCRIPTION
[0011] Referring now to the drawings, wherein like reference numerals indicate identical or similar parts throughout the several views, FIGS. 1-3 show a preferred embodiment of the present invention attached to a receptacle/container/can 1 of pipe dope that is commercially available. A threaded lid (not shown) of the receptacle 1 , which has a brush attached thereto, is removed and discarded and all of the parts shown in FIGS. 1-3 are used on the can/container/receptacle 1 , instead of the lid.
[0012] A manually activated reciprocal pump as shown in FIGS. 1-3 is like the one shown in U.S. Pat. No. 3,724,726 to Suzuki (incorporated herein by reference), but any suitable positive displacement pump could be used instead of the Suzuki pump, such as the reciprocal pump shown in U.S. Pat. Nos. 3,288,334 to Corsette, 3,414,169 to Corsette, or 4,607,765 to Ruscitti, for example (which patents are also incorporated herein by reference in their entirety).
[0013] A cup 10 is provided for receiving the threaded end 100 t of a pipe 100 . When the pipe 100 , shown in FIGS. 1 and 2 is pushed downwardly into the cup 10 , that action causes the cup 10 and plunger 9 to be pushed downwardly from the position shown in FIGS. 1 and 2 to the position in FIG. 3 . The movement of the plunger 9 and cup 10 from the FIGS. 1 and 2 positions to the FIG. 3 position causes the liquid pipe dope D in the can/container/receptacle 1 , the part in chamber 2 , to be pushed upwardly through openings 62 and 91 into the cup reservoir 10 r and then be forced out the metering apertures 10 a to evenly coat the threads 101 t of the pipe 100 . This causes exactly the same/right amount of pipe dope D to be applied to the threads each and every time that pipe threads 101 t are inserted into the cup 10 . So not only does it prevent the pipe thread dope D from being wasted, but it makes sure that enough pipe thread dope D is applied evenly to the threads 101 t.
[0014] Describing the pump portion of FIGS. 2 and 3 in more detail, it is noted that the piston 8 is normally held in the first position shown in FIG. 2 by means of a coiled spring 7 whose lower end is seated upon the bottom of the cylinder 2 and whose upper end is normally pressed against the lower surface of the enlarged portion 64 of the valve rod 6 . Therefore, under the force of the coiled spring 7 , the enlarged portion 64 of the valve rod 6 is normally pressed against the undersurface of the piston 8 so that the passage 62 is maintained firmly closed. In turn the piston 8 is pressed against the lower end of the inner cylindrical wall 31 of the cap 3 so that the upward movement of the piston 8 is stopped or limited.
[0015] Looking now to FIG. 3 , when the cup 10 is depressed by pushing down on the pipe 100 when the threads 100 t are disposed in the cup 10 , the plunger 9 is moved downwardly so that the valve rod 6 is also moved downwardly, thereby opening the hole or passage 62 . Upon downward movement of the enlarged portion 64 of the valve rod 6 , the pressure is exerted to the liquid within the cylinder 2 so that a part of the liquid is caused to rise through the axial opening 63 . After the plunger 9 is moved downwardly a distance equal to the space g, the lower end of the plunger 9 contacts with the upper end of the piston 8 so that thereafter the piston 8 is caused to move downwardly, thereby immediately opening the suction port 22 and causing the one way valve ball 5 to seat to the dashed line position. Therefore, the surrounding atmosphere is introduced into the container 1 through the space C around the plunger 9 and the suction port 22 so that the discharge of liquid from the cylinder in response to the downward movement of the piston is further facilitated. The liquid is discharged out of the container 1 through the passages 63 , 91 , cup reservoir 10 r and out through cup apertures 10 a to coat the threads 100 t of the pipe 100 .
[0016] The metering cup can be made in a different size corresponding the diameter of other standard pipe sizes, or alternatively cylindrical adapters (not shown) with metering slots corresponding to and aligned with the metering slots 10 a can be slid into the metering cup 10 to make the opening in the top of the cup 10 smaller as needed.
[0017] Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept as expressed by the attached claims.
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A method and apparatus for applying a liquid pipe dope to the threads of pipes including a metering cup for receiving the threads of a pipe in combination with a reciprocal pump that pumps the liquid pipe dope to the metering cup when the pipe is pushed into the metering cup; and then the pipe is further pushed downwardly to reciprocate the pump, causing flow of the liquid pipe dope to the threads via metering apertures.
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FIELD OF INVENTION
The present invention relates to a method of applying flock to a substrate and, more particularly, relates to a variable frequency alternating current electrostatic flocking method.
BACKGROUND OF THE INVENTION
Flocking involves the embedding of a short length of filament fiber, called flock, in an adhesive layer covering a fabric substrate. A wide range of natural and synthetic fibers can be used as flock including rayon, cotton, nylon, and polyester.
Flock is traditionally applied by three main methods; mechanical flocking, direct current electrostatic flocking and alternating current electrostatic flocking. In mechanical flocking, the flock fibers sift down onto a coated substrate that is simultaneously subject to a vigorous beating on its underside. The beating causes the substrate to vibrate which in turn causes the flock fibers to orient vertically and embed in the adhesive.
AC and DC electrostatic flocking use high voltages in the range of 30,000 volts to 120,000 volts. In both electrostatic methods, flock fibers are delivered from a hopper into the electrostatic field. The flock fibers receive a positive charge from the electrostatic field (alternating with a negative charge in AC electrostatic flocking) and are driven into the neutrally or ground potential charged adhesive coating.
Attempts have been made by the AC electrostatic flocking art to improve production speeds, pile density, and surface uniformity, as well as to reduce the amount of unattached or excess flock accumulating during fabrication. To this end, modifications have been made to the shape and size of the electrostatic grids, the electrostatic finish on the fiber and the composition of the adhesive. No attention, however, has been directed towards adjusting the frequency of the alternating electrostatic field. AC flocking is conventionally operated at 60 Hz. U.S. Pat. No. 2,376,922 discloses that 25 Hz and other frequencies will provide satisfactory results; no prior art teaching, however, teaches or suggests selectively adjusting the frequency of the alternating electrostatic field to accomplish the aforementioned objectives.
SUMMARY OF THE INVENTION
The present invention includes a method of AC electrostatic flocking. An adhesive-coated substrate is positioned relative to a hopper or other means of dispensing the flock. An alternating electrostatic field is created between electrostatically charged grids and the substrate. The frequency of the alternating electrostatic field is selectively adjusted to optimize physical characteristics of the flocked material formed thereby and/or to optimized the flocking procedure quality and speed. In one important embodiment of the invention, the flock is dispensed into a high voltage (50 kvolts) alternating electrostatic field having a selected first frequency. The high voltage provides sufficient power to drive the flock into the substrate. The resulting flocked substrate is examined and the frequency of the alternating electrostatic field is then adjusted upwards or downwards to optimize the ability of the flock to receive the electrostatic charge which in turn optimizes the physical characteristics of the resulting flocked material including flocked density and flock orientation and/or the efficiency of the flocking process. In another important embodiment of the invention, the flock is dispensed from at least two in-line flocking modules; the first flocking module having a frequency higher than the frequency of the second and any subsequent flocking modules. In another important embodiment, the frequency of the alternating electrostatic field is pre-determined based upon certain physical characteristics of the materials used to form the desired flock substrate.
Accordingly, it is a primary object of the present invention to provide a method for improving the manufacture of AC electrostatically flocked materials.
It is another abject of the present invention to improve the efficiency of AC electrostatic flocking methods.
It is another object of the present invention to provide an improved method of AC electrostatic flocking.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other details and advantages of the invention will be described in connection with the accompanying drawing in which:
FIG. 1 is a schematic view of the method of electrostatic flocking according to the preferred embodiment of the invention; and
FIG. 2 is a schematic view of an alternative embodiment of the invention incorporating multiple flocking modules.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention of AC electrostatic flocking utilizes an optimum frequency of an alternating current electrostatic field to electrostatically drive the flock into an adhesive coated substrate. By "optimum" frequency, Applicant means a frequency that, as compared to the results obtained at 60 Hz or other starting frequency, provides improvements in flock product characteristics, i.e., pile density, surface appearance, pile uniformity, etc., or improvements in the flocking method efficiency, i.e., line speed, reduction in formation of excess flock, etc. It is expected for a particular application that a range of frequencies, as opposed to a single frequency, will satisfy the foregoing definition of "optimum" frequency. For example, a frequency of 30 Hz may provide better pile density than a frequency of 40 Hz for a particular flocked material; nonetheless, because the products of the 30 Hz and 40 Hz processes each possess better pile density than that obtained at 60 Hz, both the 30 Hz and 40 Hz are optimum frequencies for the purposes of this patent.
Many variables affect the flocking efficiency of AC electrostatic methods including the cleanliness of the fiber prior to application of the electrostatic finish, the type of electrostatic finish and uniformity of coating thereof on the flock fiber, the moisture level in the coated flock and the ratio of fiber length to diameter. Each of the foregoing factors affects the ability of the flock to accept the AC electrostatic charge. Applicant has determined that a fiber that does not efficiently accept a charge at 60 Hz may operate well if the frequency is adjusted upwards or downward. At a lower cycle, for example 50 Hz, the fiber can optimally accept the charge and fire into the adhesive coated substrate. Tests by Applicant have shown that certain fibers which cannot be efficiently flocked at 60 Hz can be fabricated with commercially acceptable appearance and at suitable operating speeds by adjusting the frequency of the alternating electrostatic field between 10 cycles per second all the way up to 120 Hz.
A schematic of the method according to the preferred embodiment is shown in FIG. 1. A let-off 12 supplies the substrate of fabric or other material which is accumulated at station 14. The top side of the horizontally disposed substrate is covered with adhesive at the coating station 16. The coated substrate passes through a flocking module 18 where flock is dispensed evenly from side-to-side across the adhesive coating. The module preferably includes a long perforated insulated screen or grid that extends across the direction of movement of the substrate. Flock fibers are deposited onto the screen and a brush forces fibers therethrough. The insulated grid is maintained at approximately 50,000 volts AC and at an optimum frequency is positioned below the screen. The coated substrate is maintained at ground potential. The fibers enter the AC electrostatic field where they receive the electrostatic charge and are driven down into the coated substrate where they become implanted in and eventually adhere to the adhesive coating. The alternating electrostatic field raises loose and poorly planted fibers from the fabric substrate and reembeds them during each charge/discharge cycle. The flock align themselves in the direction of the electrostatic field lines and therefore maintain a non-random orientation relative to the substrate. A dryer operation 20 dries and cures the adhesive layer. Excess flock is removed in the vacuum and brushing station 22. A wind-up and accumulator station 24 rolls up the flocked substrate.
The optimum frequency can be determined by examination of the flocked product on the line, visually and/or with a beta gauge, and then adjusting the AC electrostatic field upwards or downwards based upon the pile density, surface uniformity, pile appearance, etc. of the sampled product. For example, if the sampled product has poor pile density, the operator would likely decrease the frequency of the electrostatic field to give the flock a better opportunity to accept the electrostatic charge. On the other hand, if pile disturbance were noted, the operator might increase the frequency of the electrostatic field to provide better surface uniformity. Even where acceptable physical characteristics are observed, the operator may still adjust the frequency of the electrostatic field. Applicant has determined that lower cycles provide faster flock weight accumulation and quicker lines speeds for certain fiber and adhesive combinations. The operator would sample a preliminary run at 50 Hz; if the product characteristics are acceptable, the operator would nonetheless lower the alternating field frequency until pile disturbance or other unacceptable product characteristic is observed. The operator would then raise the frequency until the defect disappears. Production would then ensue at the last adjusted frequency which is lower than the starting frequency.
The foregoing procedure for adjusting the frequency is inherently subjective based upon the ability of the particular operator to gauge product quality. It is also time-consuming as it may require the operator to repeatedly halt production, test samples and adjust the alternating electrostatic field frequency until an optimum frequency is found. Uniformity in processing can be achieved by having the operator refer to a pre-recorded chart containing the optimum frequency for frequently encountered precursor variables as well as desired flock material and beta gauge specifications. Combinations of some or all of the following influential precursor variables and flock material specifications are compiled together with the appropriate optimum frequency for such combinations: fiber type, fiber size, quality of fiber scouring, type of adhesive, thickness of adhesive coating, uniformity of electrostatic finish, and desired pile density.
The pre-determined optimum frequency may be derived from past production experience or by extrapolation from previously determined optimum frequencies for similar variables. Prior to the flocking operation, the operator makes the necessary measurements or examinations of the precursor materials and then uses the chart to determine the range of frequencies which will optimize product quality and/or processing for the particular variables being encountered. The production starts with the flocking module set at the pre-determined optimum frequency. Adjustments to the pre-determined optimum frequency can be made on-line by the operator to further improve the quality of the flocked material being produced as well as to improve the operating efficiency.
Further advantageous would be a software program which contains a database of the differing variable combinations and associated optimum frequencies. The production line operator would be prompted by a computer to input the variable information; the program would digest this information, compare it to the stored database and then display the optimum frequency to the operator. The operator would then adjust the frequency of the alternating electrostatic field within the range suggested by the computer. Further advantageous would be circuitry connected between the computer and the controller for the alternating electrostatic field that permits automatic adjustment of the field frequency in response to the optimum frequency output of the computer.
An alternative three-module line is shown in FIG. 2 and would work as follows. First, the operator determines the lowest frequency that can be utilized without encountering pile disturbance, for example 50 Hz. The following two modules are then set at much lower operating cycles, such as 10-20 Hz. The second and third modules can be set at the same frequency or different frequency depending upon the peculiar variables encountered. The flocking process follows the same procedure as described with respect to the single module shown in FIG. 1. The only difference being that the flock is dispensed and electrostatically driven into the adhesive coated substrate by three adjacent stands as opposed to by one single stand. Preferably, as much flock as possible is driven into the substrate by each of the modules; the throughput of the downstream modules being limited by the flock density applied in the upstream modules. The foregoing three module embodiment has been used to flock fibers that would not adequately perform in standard 60 Hz single flocking modules. Applicant has also found that flocked materials conventionally fabricated at 60 Hz and 60 ft/min line speeds are formed of similar quality at line speeds of 80-90 ft/min in a three module production line similar to the embodiment described above.
It is understood that the preceding description is given merely by way of illustration and not in limitation of the invention and that various modifications may be made thereto without departing from the spirit of the invention.
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An AC electrostatic flocking method having a variable frequency alternating electrostatic field that optimizes flocked product characteristics and/or processing efficiency. The optimized frequency can be determined on-line or from a chart or computerized database containing pre-determined optimized frequencies. The optimized frequency varies depending upon the precursors used and the processing conditions and parameters. Multiple in-line flocking modules having alternating variable frequency electrostatic fields operating at different frequencies may be utilized.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of U.S. Provisional Patent Application 62/169,097 filed Jun. 1, 2015, which is hereby incorporated herein by reference.
BACKGROUND
[0002] In slaughtering poultry, it is common to first stun the poultry, then kill the stunned poultry, and then to process the killed poultry. In stunning the poultry, it is desirable to avoid damaging the poultry tissue and to minimize movement of the poultry.
[0003] In known prior stunner systems, a pulsating low DC voltage has been applied. The pulsating DC voltage, usually in the 10-14 volt range for chickens, 14-18 volts for small turkeys, and 30-35 volts for larger turkeys, works well for most poultry processors. However such pulsating DC voltages are not acceptable for those localities requiring a so-called “stun-to-kill” approach.
[0004] In general, most stunners used outside North America are based upon a design developed in Western Europe. These European stunners operate as “water bath” stunners. This means that the birds' heads and necks are dragged through a tank of electrically charged water. This results in a very inconsistent stun, and, when combined with European style killing machines which cut only one side of the bird's neck, results in birds still being alive when reaching the scalder. This is the main reason that many European countries now require the “stun-to-kill” practice.
[0005] However, when a bird is killed in a stunner with electrical current, there is a very strong possibility of causing damage to the carcass, such as broken bones and hemorrhaging of blood vessels. Poultry processors have been looking for alternative stunning methods to improve the “stun-to-kill” procedure so that the birds can be stunned with less resulting product damage.
[0006] U.S. Pa. No. 6,019,674 of Simmons provided a step forward in the art. As described in his patent, a saline solution is contained in an elongated trough, which is mounted at the end portions of four non-electronically conducting posts. The trough is filled with saline solution. The trough has an ingress funnel arrangement designed to control the thrashing of to-be-electrically stunned birds and an elongated grid having a portion immersed in the solution and a downstream portion out of the solution. The four posts extend upwardly and terminate in threaded portions. A frame carriage is provided which has four corners, and at the four corners are suitably mounted driven gears with internal bores and threads adapted to engagingly rotate about the threaded portions of the ports. The carriage is suitably affixed to a conventional I-beam to which is movingly mounted a conventional endless cable and space shackle system for conveying birds in an upside down manner. The four mounted gears are rotatable in unison by a chain drive which may be manual, hydraulic, pneumatic or electric, whereby the trough may be selectively moved upwardly or downwardly as found necessary to vary the distance between the said I-beam and said trough to accommodate different sized shackles and/or birds.
[0007] The trough has a short extension bolted there onto to provide a first section and a second section. Both sections include a grate through which and across the top there of the bird's head is dragged.
[0008] In the first section, a pulsating DC current operating at a relatively low voltage (9-30 volts) is applied via an electrical connection, such that electricity is applied to a grate in each section. The overhead shackle line carrying the birds is at a polarity which is opposite to the polarity of electricity being supplied to the stainless steel surface submerged in saline solution and the trough. In the second section, a low AC current operating at about 30 volts is applied via the electrical connection between the shackles and the trough. The second section of the extension is electrically isolated from the first section of the main or first section of the trough. The speed of the conveyer is such that the poultry are subjected to the low voltage AC current in the extension for a period of only about two to three seconds.
[0009] While the apparatus and method described in U.S. Pat. No. 6,019,674 are effective to stun a bird such that it is unconscious, the bird is likely to still exhibit undesirable involuntary motion.
SUMMARY OF THE INVENTION
[0010] According to an illustrative embodiment, a DC voltage/current is applied for initial stunning, followed by an AC voltage/current to immobilize poultry and to further relax the muscles of the stunned poultry, such that the poultry does not exhibit involuntary motions, while at the same time avoiding or minimizing damage to the poultry tissue.
[0011] In one example embodiment, an apparatus comprises a poultry stunning apparatus, including an electrical control module configured to apply a DC current to the poultry at a voltage sufficient to stun the poultry and to apply AC current to the stunned poultry at a voltage and for a period of time sufficient to immobilize and relax the muscles of the stunned poultry, while at the same time avoiding or minimizing damage to the poultry tissue.
[0012] Optionally, the AC current is applied at a medium voltage of between about 60 and 250 VAC. Preferably, the AC current is applied at a voltage of between about 60 and 130 VAC. Most preferably, the AC current is applied at a voltage of between about 70-90 VAC.
[0013] Preferably, the AC voltage/current is applied with a dwell time between about 2 and 5 seconds.
[0014] Optionally, the AC voltage/current is applied at a frequency of about 50-60 Hz.
[0015] In another example embodiment, the invention relates to a method for stunning poultry, including the steps of applying a DC current to poultry at a voltage sufficient to stun the poultry; and applying an AC current to the stunned poultry at a voltage and for a period of time sufficient to immobilize and relax the muscles of the stunned poultry, while at the same time avoiding or minimizing damage to the poultry tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a top view of a stunning apparatus according to an example embodiment of the present invention.
[0017] FIG. 2 is a side view of a stunning apparatus according to FIG. 1 .
[0018] FIG. 3 is an end view of a stunning apparatus of FIG. 1 .
[0019] FIG. 4 is a perspective view of a stunning apparatus according to an example embodiment.
[0020] FIG. 5 is a perspective view of a stunning apparatus of FIG. 4 .
[0021] FIG. 6A is a perspective view of an electronics housing portion of the stunning apparatus of FIG. 1 and contents thereof.
[0022] FIG. 6B is a schematic view of a wiring diagram of the electronics housing and contents thereof of FIG. 6A .
[0023] FIG. 7 is a schematic flow chart of a method of operation of the stunning apparatus of FIG. 1 .
DETAILED DESCRIPTION
[0024] With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views, FIGS. 1-5 show a direct current/alternating current poultry stunning and immobilizing apparatus 10 according to an example embodiment of the present invention. The device generally includes a stunner cabinet 11 , an overhead support frame 12 , and kill line shackles 13 attached to a pre-existing overhead track 14 . Such an overhead track 14 is a common feature in many poultry processing plants.
[0025] According to an illustrative embodiment, an apparatus and method are provided for applying a low voltage DC current to poultry to stun the poultry and then applying an AC current to the poultry at a sufficient voltage and for a sufficient period of time to immobilize the poultry without damaging the tissue.
[0026] Referring to FIGS. 1 and 2 , which show a top and side view of the poultry stunning device 10 , show the stunner cabinet 11 which forms an elongated U-shaped basin (see FIGS. 3-5 ). The stunner cabinet 11 is open at each end to allow poultry to enter the cabinet 11 at a first end and exit at the second end. The cabinet 11 includes a DC stunner portion 17 , situated near the first end of the cabinet, and an AC stunner portion 27 , situated near the second end of the cabinet. The DC stunner portion 17 includes a recessed area capable of retaining water. The DC stunner portion 17 also includes a DC stunner contact grate 18 . In example embodiments, the DC stunner grate 18 is positioned at the bottom of the recessed area of the DC stunner portion 17 . The AC stunner portion 27 likewise includes an AC stunner contact grate 28 . The DC stunner grate 18 and the AC stunner grate 28 are made of electrically conductive material, such as stainless steel. The DC stunner contact grate 18 and the AC stunner contact grate 28 are electrically isolated from each other. The power supplies coupled to the DC stunner contact grate 18 and the AC stunner contact grate 28 are protected, for example, by a NEMA 4x stainless steel enclosure.
[0027] The stunner cabinet 11 also includes a salt water injection system 31 located in the DC stunner portion 17 . The salt water injection system 31 is designed to fill and maintain a level of salt water in the recessed area of the DC stunner portion 17 . The salt water injection system 31 can include an optional electronic control to ensure the salt water contains the proper saline level for delivering electric current. The cabinet 11 can include an optional pneumatic adjustment system to adjust the height of the cabinet 11 such that it can accommodate a variety of types and sizes of poultry.
[0028] The apparatus 10 also includes an overhead support frame 12 to support an existing overhead track. The overhead support frame 12 supports an overhead conveying track to which kill line shackles 13 are connected, as shown in FIGS. 2 and 3 . The kill shackles 13 are made of electrically conductive material and are designed to support poultry in an inverted position so that the bird hangs upside down with the bird's head oriented toward the bottom of the stunner cabinet 11 . The overhead support frame 12 and overhead track 14 are suitably affixed to a guide bar system 15 , which is movingly mounted to a conventional endless cable and space shackle system for conveying birds in an upside down manner in a manner understood by those skilled in the art. Optionally, an insulated rump bar and breast bar can also be used to support and hold poultry in an inverted position. In other embodiments, the apparatus can include an optional guide bar kit for accommodating plastic shackles.
[0029] The apparatus 10 can be of a modular construction which allows for additional sections to be added without replacing the entire system. The apparatus can also include a digital display and/or a voltage data logger.
[0030] As shown in FIGS. 6A and 6B , the stunner control panel consists of a NEMA 4X stainless steel enclosure containing (2) Simmons DC power packs and (1) Simmons AC power pack. Also included in the panel is (1) power conditioner and (1) primary/secondary DC power pack selector switch.
[0031] The DC power pack operates by converting standard AC voltage (115-120 VAC) to low voltage high frequency DCV. The DC voltage and amperage are displayed through a digital display located on the face of the DC power pack enclosure. The DC power pack also includes a variable transformer to raise or lower the voltage going to the DC stunner grate and an on/off switch. The AC power pack uses standard AC voltage as an input (115-120 VAC). The applied voltage is displayed through a digital display located on the face of the AC power pack enclosure. The AC power pack also includes a variable transformer to raise or lower the voltage going to the AC stunner grate and an on/off switch.
[0032] The stunner controller operates to control the DC and AC voltages applied to the bird, as described herein.
[0033] In operation, the legs of poultry are connected to the kill line shackles 13 , and the poultry is conveyed upside down along the overhead track 14 from the DC stunner contact grate 18 towards the AC stunner contact grate 28 . The salt water injection system 31 injects a sufficient amount of salt water into the DC stunner section 17 of the stunner cabinet 11 such that, as the poultry is conveyed along the overhead track 14 , the head of the poultry is sufficiently submerged in the salt water to cause an electrical connection for a pulsating DC current to flow from the DC stunner grate 18 to the kill shackles 13 . This electrical connection enables the pulsating DC current to flow through the poultry such that the poultry is stunned effectively.
[0034] According to an illustrative embodiment, as the poultry is conveyed toward the AC stunner contact grate 28 , the head of the poultry emerges from the salt water solution. As the head of the poultry comes into contact with the AC stunner contact grate 28 , the head of the poultry is damp enough to create an electrical pathway through the poultry for the AC current to flow from the AC stunner grate 28 to the kill shackles 13 , such that the poultry is immobilized.
[0035] The strength (voltage) of the DC current, the strength (voltage) of the AC current, and the dwell time of the AC current may be varied depending upon, e.g., the size of the poultry, etc. For example, the DC current may be applied as a pulsating square wave with peaks between zero volts and about 60 volts (0 VDC and 60 VDC). Preferably, the DC voltage is cycled as a square wave with a frequency of about 500 Hz (cycles per second), with a duty cycle of about 25%, resulting in an average DC voltage of about 15 VDC.
[0036] Optionally, the AC current is applied at a medium voltage of between about 60 and 250 VAC. Preferably, the AC current is applied at a voltage of between about 60 and 130 VAC. Most preferably, the AC current is applied at a voltage of between about 70-90 VAC.
[0037] Ideally, the lowest AC current is about 70 VAC. It should be appreciated that lower AC currents may also work to immobilize the poultry, but not as effectively. Preferably, the dwell time (time of application of the AC current) is between about 2 and 10 seconds, and most preferably is between about 2 and 5 seconds. Preferably, the AC current is provided at a frequency of about 50-60 Hz.
[0038] According to an illustrative embodiment, the application of DC current followed by AC current in the manner described above is effective to stun and then immobilize poultry and to relax the muscles of the stunned poultry, while at the same time avoiding or minimizing damage to the poultry tissue. This results in a generally “irreversible stun” from which poultry would not normally recover.
[0039] In a preferred form, the present invention relates to a method 50 as shown in FIG. 7 , in which according to a first step 51 the bird is passed through the stunner apparatus. In the second step 52 , the DC voltage is applied to stun the bird. In the third step 53 , the AC voltage is applied to immobilize the bird. And in the fourth step 54 , the bird exits the stunner apparatus.
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A poultry stunning apparatus and method, the apparatus including an electrical control module configured to apply a DC current to the poultry at a voltage sufficient to stun the poultry and to apply AC current to the stunned poultry at a voltage and for a period of time sufficient to immobilize and relax the muscles of the stunned poultry, while at the same time avoiding or minimizing damage to the poultry tissue. In the method, DC voltage/current is applied for initial stunning, followed by an AC voltage/current to immobilize poultry and to further relax the muscles of the stunned poultry, such that the poultry does not exhibit involuntary motions, while at the same time avoiding or minimizing damage to the poultry tissue.
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RELATED APPLICATION
[0001] This application is based on and claims the benefit of the filing date of AU patent application no. 2004901059 filed 2 Mar. 2004, the contents of which are incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a scanner for driving, principally but not exclusively, an optical fiber in a probe such as an endoscope, microscope, endomicroscope or optical coherence tomograph, including confocal versions of these.
BACKGROUND OF THE INVENTION
[0003] One existing scanning mechanism for endoscopes employs a miniature tuning fork. Another existing scanning mechanism comprises a combination of mirrors, while still another comprises a piezoelectric drive. However, in some applications (such as for within a nuclear magnetic resonance imaging machine) it may be desirable to prove a scanning mechanism of non-metallic components.
SUMMARY OF THE INVENTION
[0004] In a first broad aspect, therefore, the present invention provides a scanning mechanism for an optical probe having an optical head and an optical transmitter for transmitting light from a light source to said optical head, the scanning mechanism comprising:
a resilient member coupled to said optical transmitter; a fluid supply for providing a fluid to said head; and an exit path for said fluid from said head having a fluid entry; wherein said resilient member is located at said fluid entry so that fluid flow into said fluid entry passes over a portion of said resilient member and creates a pressure difference across said resilient member such that said resilient member is urged into said fluid entry thereby reducing said fluid flow and reducing said pressure difference, whereby said resilient member and therefore said fiber can be induced to oscillate.
[0009] In one embodiment, the exit path comprises a conduit.
[0010] In one embodiment, the fluid supply comprises a further conduit. In another embodiment the fluid supply comprises a fluid reservoir.
[0011] The fluid may be air.
[0012] In a second broad aspect, the present invention provides a scanning mechanism for an optical probe having an optical head and an optical transmitter for transmitting light from a light source to said optical head, the scanning mechanism comprising:
an inflatable reservoir coupled to said optical transmitter; a fluid supply for providing a fluid to said reservoir; and means for expelling said fluid from said reservoir; wherein said reservoir is alternately inflated and deflated so that said optical transmitter is reciprocated.
[0017] It will be understood that the reservoir may be only partially inflated and deflated.
[0018] Preferably the means for expelling said fluid from said reservoir comprises said fluid supply when operated in reverse.
[0019] Alternatively, the means for expelling said fluid comprises a spring for compressing an exterior surface of said reservoir.
[0020] Alternatively, the means for expelling said fluid comprises a resilient material surrounding or constituting said reservoir.
[0021] In a third broad aspect, the present invention provides a scanning mechanism for an optical probe having an optical head and an optical transmitter for transmitting light from a light source to said optical head, the scanning mechanism comprising:
a resilient member coupled to said optical transmitter; and an actuator for providing pressure waves, coupled to said resilient member; whereby said resilient member can be vibrated by said actuator so as to vibrate said optical transmitter.
[0025] In one embodiment, the scanning mechanism further includes a conduit coupled to said actuator for transmitting said pressure waves to said resilient member.
[0026] In a fourth broad aspect, the present invention provides a scanning mechanism for an optical probe having an optical head and an optical transmitter for transmitting light from a light source to said optical head, the scanning mechanism comprising:
a resilient member coupled to said optical transmitter; a fluid supply for providing a fluid to said head and having a fluid exit; and an exit path for said fluid to exit said head; wherein said resilient member is located at said fluid exit so that fluid flow out of said fluid exit passes over a portion of said resilient member and creates a pressure difference across said resilient member such that said resilient member is urged into said fluid exit thereby impeding said fluid flow and reducing said pressure difference, whereby said resilient member and therefore said fiber can be induced to oscillate.
[0031] In one embodiment, the fluid supply comprises a conduit.
[0032] Preferably in each of the above-described aspects that employ a resilient member, the member is adapted or operable to oscillate at a resonant frequency.
BRIEF DESCRIPTION OF THE DRAWING
[0033] In order that the invention may be more clearly ascertained, embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:
[0034] FIG. 1A is a schematic view of a fiber confocal probe with scanning mechanism according to an embodiment of the present invention;
[0035] FIG. 1B is a further schematic view of the fiber confocal probe of FIG. 1A ;
[0036] FIG. 2 is a schematic view of a detail of the scanning mechanism of a fiber confocal probe according to a further embodiment of the present invention;
[0037] FIG. 3 is a schematic view of a fiber confocal probe with acoustic scanning mechanism according to another embodiment of the present invention;
[0038] FIG. 4 is a schematic view of a positional feedback mechanism for the devices of FIGS. 1A to 3 according to the present invention;
[0039] FIG. 5 is a schematic view of an alternative positional feedback mechanism for the devices of FIGS. 1A to 3 according to the present invention;
[0040] FIG. 6 is a schematic view of an alternative reciprocating mechanism according to the present invention for the device of FIG. 1B ;
[0041] FIG. 7 is a schematic view of still another alternative reciprocating mechanism according to the present invention for the device of FIG. 1B ; and
[0042] FIG. 8 is a schematic view of a flexible sack and conduit of the reciprocating mechanism of FIG. 7 or of FIG. 8 .
DETAILED DESCRIPTION
[0043] FIG. 1A is a schematic, simplified view of a fiber confocal probe with a glass lens assembly, held together with ceramic, polymer or other non-conductive material 1 .
[0044] In this view, certain elements have been omitted for the sake of clarify, but are described below by reference to FIG. 1B .
[0045] The scanning mechanism is provided as follows.
[0046] An optical transmitter in the form of an optical fiber 2 is glued onto the side of a non-conductive resilient reed 3 . The reed is positioned at the end (in fact the fluid entry end) of a thin flexible polymer tube 4 so that air drawn into and along the tube flows past one side of the reed. A pump 5 continuously draws air up the tube. The tube 4 and the fiber 2 are enclosed within another larger tube or jacket 6 , which has the dual functions of protecting the fiber 2 and inner tube 4 and also allowing air to flow down to replace the air being sucked out by the inner tube 4 . The jacket 6 —or equivalently the atmosphere outside the jacket—acts as an air supply. The tube 4 thus acts as an exit path for air in the jacket 6 . The air flowing past one side of the reed 3 (that is, the lower side of the reed 3 in the view of FIG. 1A ) causes a reduction in pressure, owing to the Bernoulli effect. The now excess air pressure on the other (upper in FIG. 1A ) side of the reed causes the reed to bend towards the air flow and hence to somewhat obstruct the flow of air into the tube 4 . This leads to the equalization of the air pressure across the reed, which is thus able to spring back to its former, equilibrium position. This allows the air flow to be restored to its former level (or, if the flexing of the reed has fully occluded the opening of the tube 4 , to recommence) and the cycle is repeated causing the reed to vibrate or oscillate.
[0047] This vibration provides the mechanical movement which is required for the fast scan of the attached fiber 2 in front of the collimating lens 7 .
[0048] FIG. 1B is a schematic, isometric view of the same tip. The distal end of the tube 11 and the reed 12 are attached to an arm 13 which is pivoted at a point 14 by a resilient leaf spring 15 . The bending axis of the pivot is at right angles to the vibrational axis of the reed.
[0049] Between the pivot arm and the jacket wall of the probe is a fluid reservoir in the form of a small flexible polymer sack 16 . This sack is connected to another flexible polymer tube or pipe 17 which runs inside the jacket 6 to the exterior at the proximal end of the assembly. There it is joined to a mechanical pump 18 which pumps fluid 19 (liquid or gas) along the pipe 17 to the sack 16 . This inflates the sack 16 and urges the reed 12 , and therefore an optical fiber carried by the reed 12 , at right angles to the vibration of the reed described above or vertically in the view of FIG. 1B .
[0050] When the pump reverses its action the leaf spring 15 pushes the sack 16 causing the fluid to travel back along the pipe 17 , allowing the reed 12 and fiber to return to their original positions.
[0051] Thus, both X and Y scanning motions can be imparted to the reed and hence the attached fiber.
[0052] FIG. 2 is a schematic view of a detail of a further embodiment, comparable otherwise to that of FIGS. 1A and 1B , but involving two reeds. It may be desirable in some applications to position two separate reeds 21 and 22 at the end of the pipe 24 opposite one another so that they are both caused to vibrate by the passage of air up the pipe. One reed 21 carries an optic fiber 23 , while the second reed 22 acts as a counter-weight to balance the inertial reaction forces and minimize tissue damping.
[0053] FIG. 3 is a schematic view of a fiber confocal probe with a scanning mechanism according to another embodiment of the present invention. The scanning mechanism includes an actuator in the form of audio speaker 30 driven by an audio oscillator 31 , and is configured to feed pressure pulses (in this example, sound waves) into a tube 32 and down to a reed 33 . The reed carries an optical fiber 34 for transmitting excitation and return light. The tube 32 , reed 33 and optical fiber 34 are enclosed in a jacket 35 . The probe includes a glass lens assembly 36 . For clarity, the glass lens assembly 36 is shown decoupled from the jacket 35 .
[0054] In use, the pulses drive the reed 33 and hence the optical fiber 34 to mechanically oscillate. Other actuators may also be used. A feedback mechanism, described below, is used to ensure that the speaker is operated at the right frequency and phase.
[0055] Optical Pulse Operation.
[0056] It is known that sound may be generated by directing pulsed light into an absorbing medium in a resonant cavity. It is envisaged that, in a further embodiment, the reed could be vibrated by means of laser pulses passed down an optical fiber to an absorber close to the reed.
[0057] Positional Feedback.
[0058] In these embodiments, positional feedback is required, particularly for the fast scan, in order to synchronize image acquisition and also to ensure the correct phase for the drive mechanisms in the embodiments of FIGS. 2 and 3 .
[0059] Two exemplary methods of providing positional feedback are as follows:
1) Referring to FIG. 4 , a synchronizing pulse is generated in the return light by positioning a reflector 51 close to the tip 52 of the vibrating fiber 53 . As the fiber 53 passes the reflector 51 , a blip of light passes back along the fiber; its wavelength and intensity can easily be demodulated from the specimen signal and from noise. The reflector can either be a chip of plane mirror or a corner cube or cats eye reflector. It is preferably positioned towards one extreme of the excursion of the fiber movement. It is also preferably positioned on the arm that moves with the slow scan actuator. 2) Referring to FIG. 5 , positional information can also be obtained by means of additional optical fibers 61 and 62 , which are positioned so as to sample light from within a scanning head. The laser light 63 , which is emitted from the scanning fiber 64 , sweeps an arc within the sensor tip head and the intensity of the light on either side of the fiber swing will vary in synchrony with the movement of the fiber. The reflection signal may be derived from reflection from existing components 65 or special reflectors may be put in the tip chamber 66 . It is desirable to employ a highly multi-moded fiber for this purpose (for example, 100 micron PCS fiber), in order to maximize the signal and to average out optical interference fluctuations.
[0062] In FIG. 1B , an arm 13 is pivoted about point 14 by the combined effects of the inflation of polymer sack 16 and the resilient leaf spring 15 . However, other mechanisms may be used to pivot this arm or its counterpart in other embodiments. For example, FIG. 6 is a schematic view of a reciprocating mechanism 70 for pivoting an arm in various embodiments of this inventions. The mechanism 70 is shown with a pivotable arm 72 that is mounted to pivot about pivot 74 .
[0063] The reciprocating mechanism 70 comprises a pair of flexible polymer sacks 76 a and 76 b , locatable on opposite sides of arm 72 , and a corresponding pair of piston/cylinder mechanisms 78 a and 78 b . Polymer sack 76 a is in fluid communication with piston/cylinder mechanism 78 a by means of conduit 80 a , so that polymer sack 76 a can be inflated by depression of the piston of piston/cylinder mechanism 78 a . Similarly, polymer sack 76 b is in fluid communication with piston/cylinder mechanism 78 b by means of conduit 80 b , so that polymer sack 76 b can be inflated by depression of the piston of piston/cylinder mechanism 78 b . The fluid in these components can be a liquid or a gas, but is in this embodiment a liquid so as to have a low compressibility. This facilitates a prompt response the piston/cylinder mechanisms 78 a and 78 b are depressed.
[0064] FIG. 7 is a schematic view of an alternative reciprocating mechanism 90 for pivoting an arm in various embodiments of this inventions. The mechanism 90 is shown with a pivotable arm 92 that is mounted to pivot about pivot 94 .
[0065] Another reciprocating mechanism 90 comprises a pair of flexible polymer sacks 96 a and 96 b , locatable on opposite sides of arm 92 , and a corresponding pair of piston/cylinder mechanisms 98 a and 98 b in fluid communication with, respectively, polymer sack 96 a and polymer sack 96 b . In this respect reciprocating mechanism 90 is comparable to reciprocating mechanism 70 of FIG. 6 .
[0066] However, the pistons of the two piston/cylinder mechanisms are opposed relative to each other. The reciprocating mechanism 90 also includes a mechanically driven, reciprocating actuator 102 with an arm 104 located between these pistons. By driving the arm to swing in a reciprocating manner, the arm alternately depresses and then releases 106 first one and then the other piston. As a result, polymer sacks 96 a and 96 b are alternately inflated and deflated, and alternate in urging the arm 92 —being located between the sacks—towards the other sack. Arm 92 is thus caused to reciprocate about pivot 94 . Reciprocating actuator 102 can be driven by any suitable means, including an electric motor or a hydraulic pump.
[0067] It has been found that, advantageously, the sacks of the various embodiments described above (including sacks 16 , 76 a , 76 b , 96 a and 96 b ) can be made from heat-shrink. Heat-shrink of approximately 1.5 mm diameter (before being shrunk) can be clamped over a short section that will ultimately constitute the sack. The remainder of the heat-shrink is then heated and shrunk to a diameter of approximately 0.5 mm, thereby providing a conduit for connection to, for example, a piston/cylinder mechanism. The open end of the heat-shrink adjacent the sack can then be sealed by, for example, clamping or heat-sealing.
[0068] The FIG. 8 is a schematic view of a length of heat-shrink 110 after being treated in this manner. A sack 112 is formed and, as it has not been exposed to heat, retains essentially all the original flexibility of the heat-shrink material. The flexibility of the conduit 114 will generally be somewhat reduced, but adequate flexibility will remain to permit sufficient bending of the conduit during its installation in an optical apparatus.
[0069] Modifications within the scope of the invention may be readily effected by those skilled in the art. It is to be understood, therefore, that this invention is not limited to the particular embodiments described by way of example hereinabove.
[0070] In the following claims and in the preceding description of the invention, except where the context requires otherwise owing to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
[0071] Further, any reference herein to prior art is not intended to imply that such prior art forms or formed a part of the common general knowledge.
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A scanning mechanism for an optical probe having an optical head and an optical transmitter for transmitting light from a light source to the optical head, the scanning mechanism comprising a resilient member coupled to the optical transmitter, a fluid supply for providing a fluid to the head, and an exit path for the fluid from the head that has a fluid entry. The resilient member is located at the fluid entry so that fluid flow into the fluid entry passes over a portion of the resilient member and creates a pressure difference across the resilient member such that the resilient member is urged into the fluid entry thereby reducing the fluid flow and reducing the pressure difference, whereby the resilient member and therefore the fiber can be induced to oscillate.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of hydraulic circuits and, more particularly, to a variable volume reservoir.
[0003] 2. Description of the Prior Art
[0004] Hydraulic circuits typically include a hydraulic reservoir of fixed volume, a pump for circulating the hydraulic fluid within a specific circuit, a filter and a cooler. The volume of the hydraulic reservoir is typically defined in accordance with the pumping rate of the pump. In general, the capacity of the reservoir is two to three times greater than the pumping rate of the pump and sometimes even more. This results in bulky reservoirs.
[0005] Furthermore, the presence of air in hydraulic fluid is often problematic. For instance, the air may contaminate and oxidize the hydraulic fluid, cause pump cavitation problems, and may represent a risk of fire hazard.
[0006] Accordingly, efforts have been made to isolate the reserve of fluid of a hydraulic system from the atmosphere and the surrounding medium. For instance, U.S. Pat. No. 3,099,189, issued on Jul. 30, 1963 to Blondiau, discloses a fluid reservoir having a hollow body for containing a fluid and an elastic diaphragm adapted to fit within the hollow body to exert a pressure on the fluid. The bottom surface of the diaphragm follows the fluid level, according to the demand from the hydraulic circuits connected to the reservoir.
[0007] The AMSAA technical report No. 426 entitled “Hydraulic Design Guidebook Survivability And System Effectiveness” that was published by the Fluid Power Research Center Of the Oklahoma State University in August 1986 discloses a critical volume reservoir (CVR) comprising a cylindrical vessel and a piston that is axially slidable in the cylindrical vessel. The piston divides the interior space of the cylindrical vessel into first and second variable volume chambers. The first chamber is connected in fluid flow communication with a hydraulic system. The second chamber houses a compression spring acting on the piston to resist movement thereof under the pressure exerted thereon by the fluid in the first chamber. The force of reaction induced in the spring is directly transmitted from the piston to the top cover plate of the cylindrical vessel. The top cover plate must therefore be of sturdy construction. The fact that the spring is located within the cylindrical vessel also contributes to increasing the space occupied by the reservoir.
[0008] Although the variable volume reservoirs disclosed in the above-mentioned documents permits isolating the hydraulic fluid from the atmosphere, it has been found that there is still a need for a new lightweight and compact reservoir that is adapted to feed a hydraulic fluid under pressure to a hydraulic system, without inducing additional mechanical stress in the structure of the reservoir.
SUMMARY OF THE INVENTION
[0009] It is therefore an aim of the present invention to provide a minimal volume reservoir for supplying hydraulic fluid to a hydraulic system in order to meet the particular needs thereof.
[0010] It is also an aim of the present invention to isolate a hydraulic fluid from a potential source of contamination.
[0011] It is a further aim of the present invention to provide a fluid reservoir that is relatively simple and economical to manufacture.
[0012] It is a further aim of the present invention to provide a variable volume reservoir adapted to slightly pressurize a reserve of hydraulic fluid, while minimizing mechanical stress in the structure of the reservoir.
[0013] Therefore, in accordance with the present invention, there is provided a reservoir for supplying hydraulic fluid to a hydraulic system to meet the needs thereof, comprising a body defining a variable volume chamber, a port for connecting said variable volume chamber to the hydraulic system, and a restrainer urging said variable volume chamber towards a collapsed position, said restrainer being arranged so that when the variable volume chamber expands under the fluid pressure of the hydraulic fluid against a biasing force of the restrainer, a force of reaction in the restrainer equal and opposite to the biasing force is transmitted to an outer surface of the body in a direction opposite to the fluid pressure exerted by the hydraulic fluid on an inner surface of the body opposite said inner surface, thereby allowing the force of reaction in the restrainer to be counterbalanced by the fluid pressure in the variable volume chamber.
[0014] In accordance with a further general aspect of the present invention, there is provided a reservoir for use in a hydraulic circuit, comprising a body defining a variable volume chamber, a port for operatively connecting the variable volume chamber to the hydraulic circuit, said variable volume chamber having a part movable with the level of fluid in said chamber, a device opposing movement of said part under fluid pressure, said device including a traction rod connected to said part, and a biasing member acting on said traction rod to urge said part towards a collapsed position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof, and in which:
[0016] [0016]FIG. 1 is an elevation view, partly in section, of a variable volume reservoir, in accordance with a first embodiment of the present invention; and
[0017] [0017]FIG. 2 is an elevation view, partly in section, of a variable volume reservoir, in accordance with a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] [0018]FIG. 1 illustrates a variable volume reservoir 10 suited for supplying hydraulic fluid, such as oil, to mobile or stationary hydraulic systems where hauling excessive quantities of fluid is uneconomical, cumbersome or only poor in design. As will be seen hereinafter, one further advantage of using a variable volume reservoir is that the volume of the reservoir varies directly with the variation in fluid level of the reservoir, thereby preventing air from being trapped in the reservoir over the reserve of hydraulic fluid. This permits isolating the reserve of fluid from air, thereby avoiding potential particulate and chemical contamination of the fluid. The absence of air in the reservoir also reduces the risk of fire.
[0019] The variable volume reservoir 10 is designed to contain only the minimal volume of fluid required to meet the particular requirements of a specific hydraulic system.
[0020] The variable volume reservoir 10 is of compact construction and generally comprises a closed cylindrical body 12 , a piston 14 that is axially slidable in the cylindrical body 12 , a traction rod 16 extending from the piston 14 outwardly of the cylindrical body 12 , and a compression spring 18 acting on the traction rod 16 to bias the piston 14 towards a collapsed position, as illustrated in full lines in FIG. 1.
[0021] The cylindrical body 12 includes a cylindrical sidewall 20 closed at an upper end thereof by a top cover plate 22 and at a bottom end thereof by a bottom cover plate 24 . The piston 14 , the surrounding sidewall 20 and the bottom cover plate 24 define a variable volume chamber for the hydraulic fluid. According to a preferred embodiment of the present invention, the top and bottom cover plates 22 and 24 are removably fastened to the cylindrical sidewall 20 by means of a number of threaded fasteners 26 .
[0022] An air bleed valve 28 is provided on the piston 14 for allowing air contained in the hydraulic fluid to flow from the variable volume chamber to the opposite side of the piston 14 . The air collected in the space between the piston 14 and the top cover plate 22 is vented to the atmosphere through an air filter/breather 30 provided on the top cover plate 22 .
[0023] The traction rod 16 has an upper threaded end threadably engaged with a nut 32 in order to structurally connect the rod 16 to the piston 14 . An annular stop 34 is mounted about the rod 16 and maintained thereat by a nut 36 threadably engaged with a lower threaded end of the rod 16 . The rod 16 extends outwardly of the cylindrical body 12 through a central passage 38 defined in the bottom cover plate 24 .
[0024] The spring 18 is mounted about the traction rod 16 and has a first end abutted against an undersurface 40 of the bottom cover plate 24 about the central passage 38 and a second end abutted against the stop 34 . The spring 18 acts as a restrainer by exerting a biasing force on the stop 34 and, thus, the rod 16 , in a direction normal and away from the piston 14 . The corresponding force of reaction in the spring 18 , which is equal but opposite to the biasing force, is transmitted to the bottom cover plate 24 . This arrangement is advantageous in that the force of reaction is in opposition to the pressure exerted by the hydraulic fluid on the inner surface of the bottom cover plate 24 . The fluid pressure thus, counterbalances the force of reaction. In this way, no additional stress is induced by the spring 18 in the structure forming the cylindrical body 12 . Accordingly, thinner and less sturdy parts can be used in the construction of the cylindrical body 12 .
[0025] The spring 18 is received in a tubular guide 42 depending centrally downwardly from the bottom cover plate 24 . The tubular guide 42 prevents the spring 18 from buckling. Consequently, the small fluid volume contained inside the tubular guide will minimize the thermal fluid contraction-expansion effects. A port and instrumentation block 44 is provided on the tubular guide 42 . The port and instrumentation block 42 may comprise a pressure gauge 46 , a temperature switch or sensor 48 , a fluid pre-fill dry disconnect fitting and inlet and outlet ports (not shown) adapted to be respectively connected in fluid flow communication with the return and distribution lines of a hydraulic fluid circuit (not shown). The hydraulic fluid flowing in the return line of the circuit is first received in the tubular guide 42 through the inlet port defined therein. When the tubular guide 42 is full of fluid and the spring 18 completely submerged in the hydraulic fluid, the piston 14 is urged by the fluid to a position away from the bottom cover plate 24 (as illustrated in broken lines in FIG. 1) against the biasing force of the spring 18 . The spring 18 is advantageously protected against oxidation by the hydraulic fluid. The piston 14 moves with the level of fluid in the cylindrical body 12 , while maintaining the hydraulic fluid under pressure, thereby allowing supplying pressurized hydraulic fluid to a pump operatively connected to the distribution line of the hydraulic circuit. This helps in preventing pump cavitations.
[0026] As shown in FIG. 1, a drain plug 50 is threadably engaged in a hole defined in the base of the tubular guide 42 .
[0027] The level of fluid in the cylindrical body 12 may be ascertained by visual inspection of a fluid level indicating magnet 52 that is axially slidable in a transparent tube 54 provided on an outer surface of the sidewall 20 . The piston 14 is, at least partly, made of a magnetic material to ensure conjoint movement of the magnet 52 and the piston 14 .
[0028] High and low level switches 56 and 58 can be mounted on the cylindrical body 12 to send a control signal to a control system of the hydraulic system.
[0029] In the following description that pertains to the reservoir of FIG. 2, components that are identical in function and identical or similar in structure to corresponding components of the reservoir of FIG. 1 bear the same reference numeral as in FIG. 1, but are tagged with the suffix “′”, whereas components that are new to the reservoir of FIG. 2 are identified by new reference numerals in the hundreds.
[0030] The second embodiment essentially differs from the first embodiment in that the cylindrical body 12 ′ is provided in the form of a pair of end plates 22 ′ and 24 ′ flexibly connected to each other by a bellows 110 . The bellows 110 is made of a flexible impermeable material that is chemically inert to the hydraulic fluid. The end plates 22 ′ and 24 ′ and the bellows 110 define a variable volume chamber 112 for the hydraulic fluid. As illustrated in FIG. 2, the top end plate 22 ′ moves with the level of fluid in the variable volume chamber 112 against the biasing force of the compression spring 18 ′. The compression spring 18 ′ extends between a stop 114 extending inwardly from an upper end of the tubular guide 42 ′ and the stop 34 ′ provided at the lower end of the traction rod 16 ′. A hole 116 is defined in the upper end of the tubular guide 42 ′ for allowing the hydraulic fluid to pass from the tubular guide 42 ′ into the variable volume chamber 112 .
[0031] The air bleed valve 28 ′ is mounted on the top end plate 22 ′ for venting air contained in the hydraulic fluid to the atmosphere.
[0032] While the invention has been described by reference to preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. For instance, an extension spring could be used in lieu of a compression spring as described hereinbefore. Furthermore, other types of biasing members could be used to urge the variable volume chamber towards a collapsed position. It is also understood that the reservoirs illustrated in FIGS. 1 and 2 can be used in any desired orientation.
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A hydraulic fluid reservoir comprises a body defining a variable volume chamber having one end portion movable with the level of fluid in the chamber. A biasing member acting on a traction rod extending from the movable end portion restrains movement thereof under fluid pressure. The fluid pressure in the variable volume chamber advantageously counterbalances the force of reaction in the biasing member.
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RELATED APPLICATION
This application is related to, and claims priority from, U.S. Provisional Application Serial No. 60/110,507, entitled “IR NET Dial”, filed on Dec. 1, 1998, the disclosure of which is expressly incorporated herein by reference.
BACKGROUND
The present invention relates to electronic communication and more particularly to electronic communication over an infrared link, and even more particularly to a system and method for establishing a dial-up connection between a remote computing device and a network over an infrared communication link between a modem with infrared communications interface (Ir modem) and the remote computing device.
The rapid proliferation of digital computing equipment coupled with users' desires to transmit data between computing devices has resulted in the rapid expansion of digital communication networks. The most visible example of this phenomenon is the internet. The growth in wireless communication, particularly in mobile phones, has made it desirable to enable mobile phones to exchange data with computing devices like personal computers. One solution to this problem has been to provide mobile phones with an Ir modem to enable the mobile phone to establish an infrared data link with a computing or communication device like a personal computer. Using an Ir modem, a mobile phone can provide wireless data transfer between a remote computing device like a personal computer and host computing device like a server connected to a conventional wireline network.
Infrared communication links are known in the art. An infrared data link transmits information using pulses of infrared light as the carrier signal. The Infrared Data Association (IrDA), an industry association, promulgated a proposed standard for establishing infrared communication links between electronic communication devices, generally referred to as the IrDA protocol. The IrDA protocol provides a multi-layered protocol stack governing communication between electronic devices over an infrared data link. The IrDA protocol stack is depicted in FIG. 1 .
Physical layer 10 includes the hardware constituting the optical transceiver and specifies optical characteristics of the infrared signal. Physical layer 10 also manages the interface between components of the system implemented in hardware and the upper layer protocol layers, typically implemented in software. To do this, physical layer 10 also manages encoding of data, and framing for various communication speeds.
Ir Link Access Protocol (IrLAP) 20 corresponds to data link layer (layer 2) of the Open Systems Interconnection (OSI) protocol. IrLAP 20 is responsible for initiating and maintaining an infrared connection between two devices. Two devices connected by an IrLAP connection exist in a master-slave, or primary-secondary relationship. The primary device is responsible for all aspects of managing the connection. The primary device sends command frames to initiate a connection, to transmit data, and to terminate a connection. The secondary device sends response frames. The primary device is also responsible for controlling data flow and resolving data link errors. Once a connection is established, the IRLAP service implements retransmission, error correction and low-level flow control procedures to provide a reliable data transfer service between two connected devices.
The Ir Link Management Protocol (IrLMP) 30 service utilizes the reliable connection provided by the IRLAP layer 20 and adds multiplexing services to allow multiple IrLMP clients to transmit data across a single IrLAP link. To implement multiplexing, IrLMP 30 implements a higher level addressing scheme in which the Logical Service Access Point (LSAP) defines the point of access to a service or application. The LSAP is identified by a one byte number referred to as a LSAP Selector (LSAP-SEL). Using this higher level addressing scheme, multiple IrLMP services or applications may be multiplexed over a single IrLAP connection.
The Tiny Transport Protocol (TinyTP) 40 is a transport layer service that provides flow control for each IrLMP connection and also performs segmentation and reassembly (SAR). Flow control is provided using a credit-based flow control scheme in which the devices transmit credit packets indicating how many IrLMP packets they can receive.
The IrDA protocol provides three optional services: Ir Object Exchange (IrOBEX) 60 , Ir Local Area Network (IrLAN) 50 and Ir Serial and Parallel Port Emulation (IrCOMM) 70 . IrOBEX 60 is an application layer protocol that provides a simple, compact data exchange service. IrLAN 50 is an application layer protocol that emulates a LAN connection. Finally, IrCOMM 70 is an application layer protocol that emulates communication over a parallel or serial communication port.
An Ir modem requires two additional layers residing logically above the IrCOMM layer 70 to communicate with a remote computing device (e.g., a personal computer (PC) or personal digital assistant (PDA)): the AT Parser layer 90 and the Data Transfer layer 95 . The AT Parser 90 accepts commands from applications running on the remote computing device. The commands are executed and a final response is sent back, optionally preceded by one or more intermediate responses. It will be noted that in normal operation, an application running on the remote computing device generates a single AT command and waits for a response. The AT Parser 90 may also generate unsolicited responses that are sent to the application at any time during execution of commands, but more likely during the execution of two AT commands, or when the application is idle. Unsolicited commands may be used by the modem to get the attention of the application when an incoming call has been detected.
AT commands are a generic method of commanding a modem and receiving responses. Standardized AT commands are detailed in International Telecommunications Union Standard ITU-T V.25 ter. In addition to standardized commands, each manufacturer can establish proprietary commands. The application must therefore know the type of modem with which it is communicating so it can issue the correct commands to configure the modem. By way of example, the Microsoft® Windows® operating system has hundreds of modem descriptions, each with their own set of commands that are needed to make sure the modem operates properly.
The Data Transfer layer 95 is active when a call is connected and performs the transport of the data to and from the remote modem. When the Data Transfer layer 95 is active, the AT parser 90 is inactive. The transition from the AT parser 90 mode to the Data Transfer layer 95 mode (e.g., data mode) is made after either the ATD or ATA commands have completed execution and the call is connected. Transition from data mode back to AT parser mode is required before the modem can be commanded to disconnect the call. For this, one of several industry standards can be implemented by the modem manufacturers. The transition can be initiated either by in-band signalling or out-of-band signalling using the V.24 pin DTR. In-band signalling is called the “escape sequence” and consists of a pattern of characters.
The escape sequence usually consists of three plus characters in sequence (“+++”), sometimes with a required delay either before or after the sequence, or both. The escape character is configurable using an AT command. Some escape sequences must be followed by a valid AT command before it is accepted by the modem. When the transition is made, the modem sends the final result code “OK” to the application.
The IrCOMM entity is, in some implementations, exposed to the applications as a COMM-port, so the application does not require special support for IrDA to operate with, for example, an IR modem. This is called a “Virtual COMM-port”. When the application connects to this virtual COMM-port, most known IR stack implementations lock the entire IR stack. This means that other applications and protocols like OBEX over IR cannot be operative while IrCOMM is used.
Finally, the IrDA Information Access Service (IAS) 80 acts as the “yellow pages” for a device. The IAS uses a client-server model in which client objects make requests about the services available on a particular device, and the server accesses an information base of objects supplied by local services or applications to respond to the request. An IAS object is represented by a data structure having a Class Name and up to 256 Named Attributes.
Presently, IrDA-compatible infrared communication links between an Ir modem and computing devices are established using the IrCOMM application layer service. IrCOMM includes a control channel that can be used to separate control signaling from data transfer. However, because IrCOMM was designed to emulate a serial or parallel communication port, it is poorly adapted for establishing connections between mobile phones and computing devices. For example, IrCOMM lacks a feature for initializing an Ir modem to start a communication session. In the absence of an initialization feature, this function must be addressed by higher level application software. Accordingly, there is a need in the art for a compact, yet robust system and method for establishing an infrared connection between an Ir modem and a remote communication device.
SUMMARY OF THE INVENTION
The present invention addresses these and other concerns by providing an alternate service for providing a connection between a computing device and an IR modem over an infrared communication link. The service is referred to herein as the IrNetDial protocol, or service. The IrNetDial service may be added to the IrDA protocol stack in conjunction with IrLAN, OBEX, and IrCOMM and is exposed to the application through the IAS. IrNetDial defines the initial state of the modem, thereby removing the need for initialization, and provides a strictly limited set of supported AT commands and responses. Further, IrNetDial provides a defined method for switching from data mode to AT parser mode. These features simplify the application that sets up the data connection, improve reliability, and remove the need for a description of the specific modem listing the AT commands valid for the modem in use. IrNetDial encourages ad-hoc networking since the modem configuration does not have to be installed from a removable media; instead, the Ir Modem with IrNetDial can be used at once.
The present invention addresses these and other needs by providing, in one aspect, a method of initiating, in a remote computing device, a request to establish a dial-up connection with a network over an infrared communication link between the remote communication device and an Ir modem. The method comprises the steps of querying the LMP_IAS to obtain the LSAP-SEL for the infrared communication link, establishing a logical connection to an IrDA TinyTP LSAP returned by the LMP_IAS query, and executing an ATD command to initiate a dial-up connection between the remote computing device and the network over the infrared link between the remote computing device and the Ir modem.
In another embodiment, the invention provides a method of receiving, in a remote computing device, a request to establish a dial-up connection with a network over an Ir communication link between the remote computing device and an Ir modem. The invention comprises the steps of querying an IrDA LMP_IAS to obtain the LSAP-SEL for the infrared connection, establishing a logical connection to an IrDA TinyTP LSAP returned by the LMP_IAS query, and executing an ATA command to answer the request for a dial-up connection between the remote computing device and the network over the infrared link between the remote computing device and the Ir modem.
In further embodiments of the invention, an initiation string is transmitted to the Ir modem.
In further embodiments of the invention, data is transmitting between the remote computing device and the Ir modem.
In further embodiments of the invention, the communication session is terminated by transmitting an ATH command to the Ir modem.
In another aspect, the invention provides a system for establishing a dial-up connection between a remote computing device and network over an infrared communication link between the remote computing device and an infrared modem. The system comprises means for querying a LMP_IAS to obtain a LSAP-SEL for the infrared connection, means for establishing a logical connection to an IrDA TinyTP LSAP returned by the LMP_IAS query, and means for executing an ATA command to initiate a dial-up connection between the remote computing device and the network over the infrared link between the remote computing device and the Ir modem.
BRIEF DESCRIPTION OF THE DRAWINGS
These, and other objects, features and advantages of the present invention will become more readily apparent to those skilled in the art upon reading the following detailed description, in conjunction with the appended drawings, in which:
FIG. 1 is a schematic depiction of the IrDA protocol stack.
FIG. 2 is a schematic depiction of a communication system according to the present invention.
FIG. 3 is a schematic depiction of a protocol stack according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a system and method for establishing an infrared communication link between an Ir modem and a communication or computing device. In a preferred embodiment, the present invention provides the ability to set up and facilitate a wireless dial-up connection between a remote computing device and a network. Data is transferred over an infrared link between the remote computing device and the Ir modem.
1. Network Architecture
FIG. 2 presents a network architecture for dial-up networking implemented according to one embodiment of the present invention. Referring to FIG. 2, there is illustrated a remote computing device 110 connected to an Ir modem 120 by infrared communication link 115 . Ir modem 120 is connected to a mobile telephone 130 which establishes a wireless link 135 to a mobile communication network 140 . A base station 150 receives wireless signals from mobile communication network 140 and transmits the signals across a wireline link 160 through a wireline network 170 , to host computing devices 180 a and/or 180 b. A network architecture according to FIG. 2 allows a user of remote computing device 110 to use mobile communication network 140 to establish a data connection with more traditional wireline computer networks or network devices.
In one embodiment, remote computing device 110 may be embodied in a personal computer having an infrared communication port. Infrared communication ports are standard interfaces on many portable personal computers. By way of example, the Dell® Inspiron® line of portable personal computers, commercially available from Dell Computer Corporation, Round Rock, Tex., USA includes an IrDA 1.1 compatible serial infrared communication port. It will be appreciated that remote computing device 110 may be embodied as any computing device having an infrared communication port including, but not limited to, personal computers and personal digital assistants.
In one embodiment Ir modem 120 may be integrated into mobile phone 130 . An exemplary mobile phone including an integrated Ir modem is the Ericsson® model CF-888 commercially available from Ericsson. Preferably, Ir modem 120 is IrDA compliant. It will be appreciated that Ir modem 120 could be separate from mobile phone 130 . According to the invention, Ir modem 120 can operate in two different modes: an offline command mode and an online data mode. Communication sessions are started with Ir modem 120 in an offline command mode, in which there is no call established over mobile phone 130 and Ir modem 120 is waiting for instructions. When a communication session is established and a call is connected, Ir modem 120 switches to an online data mode in which the modem can transmit and receive data. In the online data mode, the only control instruction Ir modem 120 can act upon is an instruction that terminates the connection, as discussed below.
2. Data Architecture
The present invention is particularly concerned with establishing a dial-up connection over the infrared communication link 115 between remote computing device 110 and Ir modem 120 . As depicted in FIG. 2, infrared modem 120 is preferably integrated with or connected to mobile telephone 130 to enable remote computing device 110 to establish a wireless network connection.
FIG. 3 presents a schematic depiction of the protocol stacks that govern data transmission over infrared communication link 115 according to the present invention. The present invention provides a compact, robust procedure for establishing and maintaining a data connection over infrared communication link 115 using an IrDA TinyTP connection. To accomplish this, the present invention provides a service, referred to herein as IrNetDial, for establishing a data connection between a remote computing device and an infrared modem. Referring to FIG. 3, IrNetDial 350 is an optional IrDA protocol that uses the services of the lower-layer protocols (e.g., TinyTP 340 , IrLMP 330 , IrLAP 320 , Physical Layer 310 ), which are preferably IrDA compliant.
According to the present invention, user applications 370 (e.g., e-mail, file transfer applications, etc.) on remote computing device 110 pass data to the IrNetDial 350 service through an application programming interface (API) 360 . The IrNetDial service manages the process of setting up the dial-up connection, initializing the modem, if necessary, and terminating the dial-up connection when the session is finished. Advantageously, IrNetDial manages the connection process using a limited subset of commands from the ITU-T Rec. V.25 ter (July 1997) SERIAL ASYNCHRONOUS AUTOMATIC DIALING AND CONTROL, which is incorporated by reference herein.
3. V.25 ter Command Options
In a preferred embodiment, the present invention implements a limited subset of the V.25ter AT commands. These commands are transmitted in TinyTP frames. Pursuant to the V.25ter standard, the Ir modem echoes the command back to the host communication device and provides one or more responses to the AT command. Multiple commands may be transmitted in a single TinyTP frame, but a single command may not be split between TinyTP frames. By contrast, echoes and responses may be split between TinyTP frames.
The present invention follows the rules set forth in the V.25ter standard for separating AT commands. All AT commands are terminated with a <CR>. The echoed command also terminates with a <CR>. Responses from the Ir modem are of the form <CR><LF>Response<CR><LF>. Thus, each AT command issued results in the following transmission sequence between the host communication device and the Ir modem. It will be noted that one or more response codes may be returned in response to every command. In the following exemplary command sequence, it will be noted that <CR>is, by default, the character with the decimal number 13 and <LF> is the character with the decimal number 10.
TABLE 1
Exemplary Command Sequence
Direction
Content
Format
PC→Modem
Command
AT . . . <CR>
PC←Modem
Echo
AT . . . <CR>
PC←Modem
Response
<CR><LF>Response<CR><LF>
PC←Modem
Response (possible)
<CR><LF>Response<CR><LF>
The present invention implements the following commands for the V.25ter protocol. The commands are presented as a character string, followed by a verbal description of the command.
Comments
a. Link Control Commands
ATD, Dial
Description:
Initiate a data call. The phone number used to establish the connection will
consist of digits and modifiers or a stored number specification. An
abortion of the operation can be made by sending any character during
ATD connection before CONNECT is received.
Execute command:
D<n>
Dial the phone number
specified in the command as
<n>.
Dial examples:
ATD+4646120345
See below for possible
responses.
Response codes:
CONNECT<speed>
Data connection established at
the rate given in <speed>.
This puts the modem into
Online Data Mode.
NO CARRIER
Unable to establish a
connection or the connection
attempt was aborted. The
modem remains in Offline
Command Mode.
ERROR
An unexpected error occurred
while trying to establish the
connection. The modem
remains in Offline Command
Mode.
NO DIALTONE
The mobile phone is being
used for a voice call or
is not within coverage
of the network. The
modem remains in Offline
Command Mode.
BUSY
The called phone number is
engaged. The modem remains
in Offline Command Mode.
ATH, Hook control
Description:
Terminates a connection.
Execute command:
H
Response code:
NO CARRIER
Connection terminated.
Modem goes from Online
Command Mode to Offline
Command Mode.
OK
This is returned if already in
Offline Command Mode.
ERROR
Unexpected error.
ATA, Answer
Description:
Answers an incoming data call. To Receive an incoming data call the
modem has to be IrDA connected and in offline command mode. If there
is an incoming call the modem will send an unsolicited result code in
the form <CR><LF>RING<CR><LF>. It is
then possible to answer by using ATA.
Execute command:
A
Answers and initiates
connection to an incoming
call.
Examples:
ATA
Response code:
CONNECT<speed>
Data connection established at
the rate given in <speed>.
ERROR
This is returned if not a data
call, or if no call at all.
b. Initiation Commands
AT+DS Data Compression Mode
Description:
Defines the compression parameters and negotiation used for V.42 bis
compression specified in ITU-T Recommendation, Data Compression
Procedures for Data Circuit Terminating Equipment (DCE)
Using Error Correction Procedures.
Set command: +DS=[<dir>,[<neg>,[<md>,[<ms>]]]]
<dir>
0
Disable V.42bis compression
1
Enable V.42bis compression on
transmitted data
2
Enable V.42bis compression
on received data
3
Enable V.42bis compression on
received and transmitted data.
Default = 3.
<neg>
0
Connect even if the compression
protocol does not comply with
that specified by dir.
1
Disconnect if compression protocol
does not comply with dir.
Default = 0.
<md>
512-4096
Defines the maximum dictionary
size. This value will be amended
automatically to comply with any
memory constraints.
Default = 2048 bytes.
<ms>
6,250
Defines the maximum string
length. Default = 32 bytes.
4. Initiation String and Default Settings
The Ir modem must be initialized before opening a communication session. A modem manufacturer may specify a default initiation setting. An exemplary default setting of an IrModem may be specified in accordance with ITU-T Recommendation V.25, ter, as follows.
Echo
ON, EI
Results
Verbose, V1
Result code suppression
OFF, QØ
Esc. Character
=“+”, S2=43,
Enter (CR)
=dec. symbol # 13, S3=13
Linefeed (LF)
=dec. symbol # 10, S4=10
V.42bis compression
Enabled on received and transmitted data,
always negotiate, max dictionary size
2048, string length 32.
Provided the user is willing to accept the default settings, no special initialization instruction by the PC are necessary when opening an IrNETDial connection. The IrModem preferably includes means for initializing itself when an infrared connection is opened. Such means may be embodied as logic instructions operating on a suitable microprocessor. However, the remote computing device may turn compression on and off.
To enable future expanded capabilities in the modem, each modem vendor can provide an initiation string for use with its modem. The initiation string contains AT commands configuring the modem in a desired way for dial-up networking. The PC must, before dial-up, send the initiation string to the modem. This string could be automatically stored in a memory location associated with the PC when the modem is installed. By using the phone Plug n'Play number read by IrDA_IAS request, a control that the right modem is installed can be made. It may also be displayed in the modem configuration menu so it can be edited manually. In a preferred embodiment, the string format is as follows:
Each command in the string should be written using only the set command itself (i.e., without the characters AT in format).
The character <CR> shall NOT be included after each command.
Each command shall be separated by a semicolon (;).
EXAMPLE
Ir Modem Initiation String
+XTRA=1,5;+NEW=3
5. Operation
A dial-up connection may be established over the infrared link between the remote computing device and the Ir modem pursuant to the following procedures: referring to FIG. 2, when remote computing device 110 initiates an outgoing call, a processor in the remote computing device 110 queries the IrDA LMP-IAS to obtain the LSAP-SEL for the connection and establishes a logical connection to the IrDA Tiny TP LSAP-SEL returned by the IAS query. Ir modem 120 is initialized for dial-up services. Ir modem 120 may be self-initialized or an initiation string may be transmitted with extra setting, if existing, from remote computing device 110 to the Ir modem 120 . Remote computing device 110 establishes a dial-up connection by transmitting an ATD command with the desired destination phone number. When destination device (e.g. 180 a, 180 b ) answers, remote computing device 110 and Ir modem 120 exchange data pursuant to existing IrDA procedures, and the data may be transmitted to destination device 180 a, 180 b. Remote computing device 120 may end the telecommunication session by sending an escape sequence (e.g., +++) and an ATH command. The IR communication session may then be disconnected.
A slightly modified process applies when remote computing device 110 receives an incoming call through Ir modem 120 . In this case, an application on remote computing device 110 typically initiates the infrared link between remote computing device 110 and Ir modem 120 and waits for an incoming call, which is indicated by the IR modem sending the unsolicited code “RING” to the application. The infrared connection is then established in substantially the same manner. Remote computing device 110 queries the LMP-IAS 380 to obtain the LSAP-SEL for the connection and establishes a logical connection to the IrDA Tiny TP LSAP-SEL returned by the IAS query. Ir modem 120 is initialized for dial-up services. Ir modem 120 is self-initialized, but an initiation string may be transmitted with extra settings, if existing, from remote computer 110 . When Ir modem 120 receives an incoming call, Ir modem 120 transmits a ring indication in the form of an unsolicited result code in the following format: <CR><LF>RING<CR><LF>. Remote computing device 110 answers the call using the ATA command. Data may then be exchanged pursuant to existing IrDA procedures. Remote computing device 110 may end the telecommunication session by sending an escape sequence (e.g. +++) and an ATH command. The IR communication session may then be disconnected.
It will be noted that if the call is terminated for some reason, Ir modem 120 sends an unsolicited response <CR><LF>NO CARRIER<CR><LF>. Similarly, if the infrared connection for some reason is obstructed or interrupted, the general IrDA rules shall be followed with a timeout. If the infrared connection is then terminated, Ir modem 120 will, in turn, terminate the connection.
6. IAS and Hint Bits
To implement this service a new Class Name must be added to the LMP_IAS. The invention may be implemented by adding a new Class Name IrModem to the LMP_IAS. The Class Name IrModem has the attributes IrDA:TinyTP:LSAP-SEL. The correct LSAP-SEL may be retrieved by performing an LMP_IAS GetValueByClass query on the IrModem Class Name. IAS queries are defined in IrDA protocol.
To give the proper service hints in the device information field, the hint bit for the modem is set so that it is possible make an early detection of this service in an IrDA connection. A hint bit is a bit that indicates which services are included in the Ir device. The hint bit can be used by the Ir stack to determine whether the device has the services requested by the application before the higher level IrDA protocols connect to the device. Hint bits are discussed in the IrDA protocol.
The present invention has been described with reference to particular embodiments. It will be understood that the claims are not limited to the particular embodiments described herein, but should be construed to cover structural equivalents and modifications consistent with the ordinary skill in the art.
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A system and method for initiating a dial-up connection between a remote computing device and a network over an infrared link between the remote computer and an infrared modem is disclosed. A unique protocol defines the universe of commands, responses, and behavior of the modem regarding initialization, response sequence, and switching between data transfer mode and AT command mode.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This divisional application claims the benefit of U.S. application Ser. No. 12/582,718, filed on Oct. 21, 2009, the contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to a buffer, and more particularly, to a buffer capable of increasing the responding speed and prolonging the lifespan.
[0004] 2. Description of the Prior Art
[0005] In the design of a general buffer, the responding speed is limited by the bias voltage of the electrical components of the buffer. That is, if the bias voltage of the buffer is raised up, the responding speed of the buffer increases. However, in this way, the lifespan of the buffer is reduced, causing a great inconvenience.
SUMMARY OF THE INVENTION
[0006] The present invention provides a buffer-driving circuit capable of increasing a responding speed of a buffer circuit and a lifespan of the buffer circuit. The buffer circuit has a transmitting transistor and a voltage-sharing transistor. The transmitting transistor is coupled between a first voltage source and the voltage-sharing transistor. The voltage-sharing transistor is coupled between the transmitting transistor and an output end of the buffer circuit. The first voltage source provides a first voltage. The buffer circuit is utilized for buffering an input signal and accordingly generating an output signal from the output end of the buffer circuit. The buffer-driving circuit comprises a level-shifting circuit, a pulse generator, and a bias circuit. The level-shifting circuit is utilized for shifting a voltage level of the input signal so as to generate a level-shifting signal. When the voltage level of the input signal is equal to a first predetermined voltage level, the level-shifting signal is equal to the first voltage. When the voltage level of the input signal is equal to a second predetermined voltage level, the level-shifting signal is equal to a second voltage. The pulse generator is utilized for generating a pulse signal with a predetermined period when the input signal is in a transition state. The bias circuit comprises a first inverter, and a second inverter. The first inverter comprises an input end, an output end, a first power end, and a second power end. The input end of the first inverter is coupled to the level-shifting circuit for receiving the level-shifting signal. The output end of the first inverter is coupled to a control end of the transmitting transistor, for outputting a transmitting gate-driving signal so as to control the transmitting transistor. The first power end of the first inverter is coupled to the first voltage source, for receiving the first voltage. The second inverter comprises an input end, an output end, a first power end, and a second power end. The input end of the second inverter is coupled to the pulse generator, for receiving the pulse signal. The output end of the second inverter is coupled to a control end of the voltage-sharing transistor and the second power end of the first inverter, for outputting a voltage-sharing gate-driving signal. The first power end of the second inverter is coupled to a second voltage source, for receiving the second voltage. The second power end of the second inverter is coupled to a third voltage source, for receiving a third voltage. An amplitude of the transmitting gate-driving signal is between the first voltage and the voltage-sharing gate-driving signal. An amplitude of the voltage-sharing gate-driving signal is between the second voltage and the third voltage.
[0007] The present invention further provides a buffer with a fast responding speed and a long life span. The buffer is utilized for buffering an input signal so as to generate an output signal. The buffer comprises a buffer circuit, and a buffer-driving circuit. The buffer circuit comprises a P-type buffer circuit, and an N-type buffer circuit. The P-type buffer circuit comprises a P-type transmitting transistor, and a P-type voltage-sharing transistor. The P-type transmitting transistor comprises a first end, a second end, and a control end. The first end of the P-type transmitting transistor is coupled to a first voltage source, for receiving a first voltage. The control end of the P-type transmitting transistor is utilized for receiving a P-type transmitting gate-driving signal. The P-type voltage-sharing transistor comprises a first end, a second end, and a control end. The first end of the P-type voltage-sharing transistor is coupled to the second end of the P-type transmitting transistor. The second end of the P-type voltage-sharing transistor is coupled to an output end of the buffer, for receiving the output signal. The control end of the P-type voltage-sharing transistor is utilized for receiving a P-type voltage-sharing gate-driving signal. The N-type buffer circuit comprises an N-type transmitting transistor, and an N-type voltage-sharing transistor. The N-type transmitting transistor comprises a first end, a second end, and a control end. The first end of the N-type transmitting transistor is coupled to a second voltage source, for receiving a second voltage. The control end of the N-type transmitting transistor is utilized for receiving an N-type transmitting gate-driving signal. The N-type voltage-sharing transistor comprises a first end, a second end, and a control end. The first end of the N-type voltage-sharing transistor is coupled to the second end of the N-type transmitting transistor. The second end of the N-type voltage-sharing transistor is coupled to the output end of the buffer, for receiving the output signal. The control end of the N-type voltage-sharing transistor is utilized for receiving an N-type voltage-sharing gate-driving signal. The buffer-driving circuit comprises a P-type buffer-driving circuit, and an N-type buffer-driving circuit. The P-type buffer-driving circuit comprises a P-type level-shifting circuit, a P-type pulse generator, and a P-type bias circuit. The P-type level-shifting circuit is utilized for shifting a voltage level of the input signal so as to generate a P-type level shifting signal. When the voltage level of the input signal is equal to a first predetermined voltage level, the P-type level shifting signal is equal to the first voltage. When the voltage level of the input signal is equal to a second predetermined voltage level, the P-type level-shifting signal is equal to a third voltage. The P-type pulse generator is utilized for generating a P-type pulse signal with a first predetermined period according to a rising edge of the input signal. The P-type bias circuit comprises a first inverter, and a second inverter. The first inverter comprises an input end, an output end, a first power end, and a second power end. The input end of the first inverter is coupled to the P-type level-shifting circuit, for receiving the P-type level-shifting signal. The output end of the first inverter is coupled to the control end of the P-type transmitting transistor, for outputting the P-type transmitting gate-driving signal. The first power end of the first inverter is coupled to the first voltage source, for receiving the first voltage. The second inverter comprises an input end, an output end, a first power end, and a second power end. The input end of the second inverter is coupled to the P-type pulse generator, for receiving the P-type pulse signal. The output end of the second inverter is coupled to the control end of the P-type voltage-sharing transistor, for outputting the P-type voltage-sharing gate-driving signal. The first power end of the second inverter is coupled to a second voltage source, for receiving the second voltage. The second power end of the second inverter is coupled to a third voltage source, for receiving the third voltage. The N-type buffer-driving circuit comprises an N-type level-shifting circuit, an N-type pulse generator, and an N-type bias circuit. The N-type level-shifting circuit is utilized for shifting the voltage level of the output signal so as to generating an N-type level-shifting signal. When the voltage level of the input signal is equal to the first predetermined voltage level, the level-shifting signal is equal to a fourth voltage. When the voltage level of the input signal is equal to the second predetermined voltage level, the level-shifting signal is equal to the second voltage. The N-type pulse generator is utilized for generating an N-type pulse signal with a second predetermined period according to a falling edge of the input signal. The N-type bias circuit comprises a third inverter, and a fourth inverter. The third inverter comprises an input end, an output end, a first power end, and a second power end. The input end of the third inverter is coupled to the N-type level-shifting circuit, for receiving the N-type level-shifting signal. The output end of the third inverter is coupled to the control end of the N-type transmitting transistor, for outputting the N-type transmitting gate-driving signal. The first power end of the third inverter is coupled to the second voltage source, for receiving the second voltage. The fourth inverter comprises an input end, an output end, a first power end, and a second power end. The input end of the fourth inverter is coupled to the N-type pulse generator, for receiving the N-type pulse signal. The output end of the fourth inverter is coupled to the control end of the N-type voltage-sharing transistor, for outputting the N-type voltage-sharing gate-driving signal. The first power end of the fourth inverter is coupled to the first voltage source, for receiving the first voltage. The second power end of the fourth inverter is coupled to a fourth voltage source, for receiving the fourth voltage. An amplitude of the P-type transmitting gate-driving signal is between the first voltage and the P-type voltage-sharing gate-driving signal. An amplitude of the P-type voltage-sharing gate-driving signal is between the second voltage and the third voltage. An amplitude of the N-type transmitting gate-driving signal is between the second voltage and the N-type voltage-sharing gate-driving signal. An amplitude of the N-type voltage-sharing gate-driving signal is between the first voltage and the fourth voltage.
[0008] The present invention further provides a method capable of increasing a responding speed of a buffer and prolonging a lifespan of the buffer. The method comprises detecting an edge of an input signal of the buffer, triggering a pulse signal with a predetermined period according to the detected edge of the input signal, and driving the buffer according to the pulse signal and the input signal so as to generate an output signal.
[0009] The present invention further provides a buffer of buffering an input signal so as to generate an output signal from an output end. The buffer comprises a buffer-driving circuit, a transmitting transistor, and a voltage-sharing transistor. The buffer-driving circuit is utilized for receiving the input signal so as to generate a voltage-sharing gate-driving signal and a transmitting gate-driving signal. The transmitting transistor is coupled to a first voltage source, for receiving the transmitting gate-driving signal. The voltage-sharing transistor is coupled between the output end and the transmitting transistor, for receiving the voltage-sharing gate-driving signal. When the input signal is a first voltage, the transmitting gate-driving signal is equal to a first predetermined voltage during a first predetermined period, the transmitting driving signal is equal to a second predetermined voltage beyond the first predetermined period.
[0010] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagram illustrating a buffer with a fast responding speed and a long lifespan of the present invention.
[0012] FIG. 2 is a time diagram illustrating the relation between the signals in the buffer of the present invention.
DETAILED DESCRIPTION
[0013] Please refer to FIG. 1 . FIG. 1 is a diagram illustrating a buffer 1000 with a fast responding speed and a long lifespan of the present invention. As shown in FIG. 1 , the buffer 1000 comprises a buffer circuit 1100 , and a buffer-driving circuit 1200 . The buffer 1000 is utilized for buffering an input signal V IN so as to output an output signal V OUT . Since the low voltage level and the high voltage level of the input signal V IN can be designed as desired, the logic “0” and “1” is used for representing the low voltage level and the high voltage level of the input signal V IN in the present invention, respectively. The high voltage level of the output signal V OUT is V DD (the voltage provided by the voltage source V DD ), and the low voltage level of the output signal V OUT is V SS (the voltage provided by the voltage source V SS ). In addition, the voltage source V SS can be a ground end. The output end of the buffer 1000 is coupled to a capacitor C OUT . The capacitor C OUT is coupled between the output end of the buffer 1000 and the voltage source V SS .
[0014] The buffer circuit 1100 comprises a P-type buffer circuit 1110 and an N-type buffer circuit 1120 . The P-type buffer circuit 1110 comprises a P-type transmitting transistor Q P and a P-type voltage-sharing transistor Q PS . The N-type buffer circuit 1120 comprises an N-type transmitting transistor Q N and an N-type voltage-sharing transistor Q NS . The transmitting transistors Q P and Q N are utilized for receiving the input signal V IN driven by the buffer-driving circuit 1200 , respectively, and so as to generate the output signal V OUT . The voltage-sharing transistors Q PS and Q NS are utilized for reducing the voltage drops across the transmitting transistors Q P and Q N , respectively, for prolonging the lifespan of the transmitting transistors Q P and Q N . The transmitting transistor Q P is coupled to the voltage source V DD ; the transmitting transistor Q N is coupled to the voltage source V SS . Generally speaking, for increasing the responding speed of the buffer 1000 , the voltage level of the voltage source V DD is raised up or the voltage level of the voltage source V SS is lowered down. However, this causes the voltage drops suffered by the transmitting transistors Q P and Q N increase at the same time, reducing the lifespan. Hence, the voltage-sharing transistors Q PS and Q NS are utilized for sharing the voltage drops across the transmitting transistors Q P and Q N , respectively, for prolonging the lifespan of the transmitting transistors Q P and Q N . For the normal operation of the transmitting transistors Q P and Q N , the voltage-sharing transistors Q PS and Q NS have to be biased properly. Thus, in the buffer-driving circuit 1200 , two voltage sources V BP and V BN (respectively for providing the voltage V BP and V BN ) are required for properly biasing the voltage-sharing transistors Q PS and Q NS . In addition, the transistors Q P and Q PS can be P channel Metal Oxide Semiconductor (PMOS) transistors; the transistors Q N and Q NS can be N channel Metal Oxide Semiconductor (NMOS) transistors.
[0015] The buffer-driving circuit 1200 comprises a P-type buffer-driving circuit 1210 and an N-type buffer-driving circuit 1220 for driving the P-type buffer circuit 1110 and the N-type buffer circuit 1120 , respectively. The P-type buffer-driving circuit 1210 comprises a P-type level-shifting circuit 1211 , a P-type pulse generator 1212 , and a P-type bias circuit 1213 . The N-type buffer-driving circuit 1220 comprises an N-type level-shifting circuit 1221 , an N-type pulse generator 1222 , and an N-type bias circuit 1223 .
[0016] In the present embodiment, the P-type level-shifting circuit 1211 shifts the voltage level of the input signal V IN for outputting the P-type level-shifting signal V PS : when the input signal V IN represents logic “0”, the voltage level of the level-shifting signal V PS is equal to the voltage V BP (provided by the voltage source V BP , wherein the voltage level of the voltage V BP is between the voltage V DD and the voltage V SS ); when the input signal V IN represents logic “1”, the voltage level of the level-shifting signal V PS is equal to the voltage V DD (provided by the voltage source V DD ).
[0017] The P-type pulse generator 1212 generates the P-type pulse signal V PP according to the transition of the input signal V IN : when the input signal V IN changes from representing logic “0” to logic “1” (that is, when the rising edge of the input signal V IN occurs), the P-type pulse generator 1212 triggers the P-type pulse signal V PP (edge trigger). The high voltage level of the P-type pulse signal V PP is equal to the voltage V BP , and the low voltage level of the P-type pulse signal V PP is equal to the voltage V SS ; the pulse width of the P-type pulse signal V PP is equal to a predetermined period T P , and the P-type pulse signal V PP is a rising pulse signal.
[0018] The P-type bias circuit 1213 comprises inverters INV 1 and INV 2 . The inverter INV 1 is mainly utilized for converting the P-type level-shifting signal V PS into the P-type transmitting gate-driving signal V PGD so as to drive the transmitting transistor Q P . The inverter INV 2 is mainly utilized for converting the P-type pulse signal V PP into the P-type voltage-sharing gate-driving signal V PSGD so as to bias the voltage-sharing transistor Q PS .
[0019] More particularly, the input end of the inverter INV 1 is utilized for receiving the P-type level-shifting signal V PS ; the output end of the inverter INV 1 is coupled to the control end (gate) of the transmitting transistor Q P for outputting the P-type transmitting gate-driving signal V PGD so as to control the transmitting transistor Q P . In addition, the power ends of the inverter INV 1 are coupled to the voltage sources V DD and the output end of the inverter INV 2 . Hence, although the transmitting gate-driving signal V PGD is inverted to the P-type level-shifting signal V PS , the amplitude of the transmitting gate-driving signal V PGD is limited between the voltage level of the voltage source V DD and the signal outputted by the inverter INV 2 .
[0020] The input end of the inverter INV 2 is utilized for receiving the P-type pulse signal V PP and accordingly inverting the P-type pulse signal V PP so as to output the voltage-sharing gate-driving signal V PSGD . The power ends of the inverter INV 2 are coupled to the voltage source V BP and V SS . Therefore, the amplitude of the voltage-sharing gate-driving signal V PSGD is limited between the voltages V BP and V SS . Consequently, when the voltage level of the voltage-sharing gate-driving signal V PSGD is equal to the voltage V BP , the amplitude of the transmitting gate-driving signal V PGD is between the voltages V DD and V BP ; when the voltage level of the voltage-sharing gate-driving signal V PSGD is equal to the voltage V SS , the amplitude of the transmitting gate-driving signal V PGD is between the voltages V DD and V SS .
[0021] As a result, in the P-type buffer-driving circuit 1210 , when the input signal V IN is in the transition state (the rising edge), the received transmitting gate-driving signal V PGD of the transmitting transistor Q P can be lowered more (lower than the voltage V BP ) through the P-type pulse signal V PP generated by the P-type pulse generator. In this way, the transmitting transistor Q P can be turned on more completely so that the current passing through the transmitting transistor Q P becomes larger, increasing the speed of charging the capacitor V OUT and accelerating the responding speed of the buffer 1000 .
[0022] The N-type level-shifting circuit 1221 shifts the voltage level of the input signal V IN for outputting the N-type level-shifting signal V NS : when the input signal V IN represents logic “1”, the voltage level of the level-shifting signal V NS is equal to the voltage V BN (provided by the voltage source V BN , wherein the voltage level of the voltage V BN is between the voltages V DD and V SS ); when the input signal V IN represents logic “0”, the voltage level of the level-shifting signal V NS is equal to the voltage V SS (provided by the voltage source V SS ).
[0023] The N-type pulse generator 1222 generates the N-type pulse signal V NP according to the transition of the input signal V IN : when the input signal V IN changes from representing logic “1” to logic “0” (that is, when the falling edge of the input signal V IN occurs), the N-type pulse generator 1222 triggers the N-type pulse signal V NP (edge trigger). The high voltage level of the N-type pulse signal V NP is equal to the voltage V DD , and the low voltage level of the N-type pulse signal V NP is equal to the voltage V BN ; the period length of the N-type pulse signal V NP is equal to the predetermined period T P , similarly. The N-type pulse signal V NP is a falling pulse signal.
[0024] The N-type bias circuit 1223 comprises inverters INV 3 and INV 4 . The inverter INV 3 is mainly utilized for converting the N-type level-shifting signal V NS into the N-type transmitting gate-driving signal V NGD so as to drive the transmitting transistor Q N . The inverter INV 4 is mainly utilized for converting the N-type pulse signal V NP into the N-type voltage-sharing gate-driving signal V NSGD so as to bias the voltage-sharing transistor Q NS .
[0025] More particularly, the input end of the inverter INV 3 is utilized for receiving the N-type level-shifting signal V NS ; the output end of the inverter INV 3 is coupled to the control end (gate) of the transmitting transistor Q N for outputting the N-type transmitting gate-driving signal V NGD so as to control the transmitting transistor Q N . In addition, the power ends of the inverter INV 3 are coupled to the voltage source V SS and the output end of the inverter INV 4 . Hence, although the transmitting gate-driving signal V NGD is inverted to the N-type level-shifting signal V NS , the amplitude of the transmitting gate-driving signal V NGD is limited between the voltage level of the voltage source V SS and the signal outputted by the inverter INV 4 .
[0026] The input end of the inverter INV 4 is utilized for receiving the N-type pulse signal V NP and accordingly inverting the N-type pulse signal V NP so as to output the voltage-sharing gate-driving signal V NSGD . The power ends of the inverter INV 4 are coupled to the voltage sources V DD and V BN . Therefore, the amplitude of the voltage-sharing gate-driving signal V NSGD is limited between the voltages V BP and V SS . Consequently, when the voltage level of the voltage-sharing gate-driving signal V NSGD is equal to the voltage V BN , the amplitude of the transmitting gate-driving signal V NGD is between the voltages V SS and V BN ; when the voltage level of the voltage-sharing gate-driving signal V NSGD is equal to the voltage V DD , the amplitude of the transmitting gate-driving signal V NGD is between the voltages V DD and V SS .
[0027] As a result, in the N-type buffer-driving circuit 1220 , when the input signal V IN is in the transition state (the falling edge), the received transmitting gate-driving signal V NGD of the transmitting transistor Q N can be raised up more (higher than the voltage V BN ) through the N-type pulse signal V NP generated by the N-type pulse generator. In this way, the transmitting transistor Q N can be turned on more completely so that the current passing through the transmitting transistor Q N becomes larger, increasing the speed of discharging the capacitor V OUT and accelerating the responding speed of the buffer 1000 .
[0028] According to the above-mentioned description, the basic idea of the buffer-driving circuit of the present invention is to generate the pulse signal when the input signal is in the transition state for enhancing the amplitude of the control signal for the buffer circuit so as to increase the responding speed of the buffer of the present invention.
[0029] In addition, the period length T P of the P-type pulse signal V PP and the N-type pulse signal V NP can be adjusted. If the user is to accelerate the responding speed of the buffer of the present invention, the period length T P can be prolonged; otherwise, if the user is to prolong the lifespan of the components of the buffer of the present invention, the period length T P can be shortened. The above-mentioned condition can be adjusted as desired. In other words, the buffer provided by the present invention is more flexible for designs. Furthermore, in the above-mentioned embodiment, although the period length of the P-type pulse signal V PP and the N-type pulse signal V NP are both equal to T P , however, the period length of the P-type pulse signal V PP and the N-type pulse signal V NP can be designed to be different in the practical application according the requirement. For example, if the aspect ratios of the PMOS transistor and the NMOS transistor of the buffer circuit are not matching, the pulse widths of the N-type pulse signal V PP and the N-type pulse signal V NP have to be properly adjusted for the rising speed of the output signal V OUT equal to the falling speed of the output signal V OUT .
[0030] It is noticeable that the application range of the buffer-driving circuit of the buffer of the present invention is related to the transition frequency of the input signal V IN . More particularly, if the transition frequency of the input signal V IN is too high, that is, the period length of the input signal V IN in the logic “0” state or logic “1” state may be shorter than the period length of the P-type pulse signal V PP and the N-type pulse signal V NP , the buffer of the present invention may operate incorrectly. Thus, the pulse widths of the pulse signals of the present invention are limited by the shortest period that the input signal V IN is in the logic “0” state or the logic “1” state. However, in the practical application of the digital circuit, the shortest period of the input signal V IN in the logic “0” state or the logic “1” state is predetermined. Hence, the period length (pulse width) of the pulse signals can be designed according to the shortest period. For instance, in the design of the digital circuit, the shortest period of the input signal V IN in the logic “0” state or the logic “1” state is equal to a fixed cycle. Thus, as long as the period length of the pulse signals are not longer than the fixed cycle, the buffer of the present invention can operate correctly.
[0031] Please refer to FIG. 2 . FIG. 2 is a time diagram illustrating the relation between the signals in the buffer of the present invention. As shown in FIG. 2 , when the input signal V IN changes from logic “0” into logic “1” (the rising edge), the P-type pulse generator 1212 is triggered to generate a pulse (signal V PP ) going up from the voltage V SS to the voltage V BP with the predetermined period T P . This pulse causes that the voltage-sharing gate-driving signal V PSGD goes down from the voltage V BP to the voltage V SS , and the transmitting gate-driving signal V PGD simultaneously goes down to the voltage V SS , so that the transmitting transistor Q P is turned on more completely. In this way, more currents flow from the voltage source V DD to the output end O of the buffer 1000 through the voltage-sharing transistor Q PS , increasing the speed of charging the capacitor C OUT . For instance, it can be seen that in the output signal V OUT of FIG. 2 , the rising speed of the first rising edge of the output signal V OUT is faster than the rising speed of the output signal of a conventional buffer (shown by the dot line) because of the P-type pulse signal. When the input signal V IN changes from logic “1” into logic “0” (the falling edge), the N-type pulse generator 1222 is triggered to generate a pulse (signal V NP ) going down from the voltage V DD to the voltage V BN with the predetermined period T P . This pulse causes that the voltage-sharing gate-driving signal V NSGD goes up from the voltage V BN to the voltage V DD , and the transmitting gate-driving signal V NGD simultaneously goes up to the voltage V DD , so that the transmitting transistor Q N is turned on more completely. In this way, more currents drains from the output end O of the buffer 1000 to the voltage source V SS through the voltage-sharing transistor Q NS , increasing the speed of discharging the capacitor C OUT . For instance, it can be seen that in the output signal V OUT of FIG. 2 , the falling speed of the first falling edge of the output signal V OUT is faster than the falling speed of the output signal of a conventional buffer (shown by the dot line) because of the N-type pulse signal.
[0032] In conclusion, the buffer-driving circuit provided by the present invention can increase the responding speed of the buffer and prolong the life span of the buffer. In other words, the responding speed of the buffer increases and the lifespan of the buffer is prolonged by means of the pulse signals provided by the buffer-driving circuit. If the user is to accelerate the responding speed of the buffer, the pulse widths of the pulse signals can be prolonged; otherwise, if the user is to prolong the lifespan of the components of the buffer circuit, the pulse widths of the pulse signal can be shortened. The above-mentioned condition can be adjusted as desired. In other words, the buffer-driving circuit and the buffer provided by the present invention are more flexible for designs, providing a great convenience.
[0033] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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A method for increasing responding speed and lifespan of a buffer includes detecting an edge of an input signal of the buffer, triggering a pulse signal with a predetermined period according to the detected edge, and driving the buffer for generating an output signal according to the pulse signal and the input signal.
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CROSS REFERENCES
U.S. patent applications filed simultaneously herewith, one in the names of Barry L. Frost and Theodore A. Malott entitled "Control for Mechanical Transmission", Ser. No. 229,472, filed Jan. 29, 1981, and the other in the name of Theodore A. Malott entitled "Lost Motion Transmission Control Cams", Ser. No. 229,402, filed Jan. 29, 1981, both assigned to the Assignee of the present invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The field of art to which this invention pertains includes shift control systems for multiple input - multiple output transmissions which provide a plurality of speed ratios in response to the movement of an operator's shift lever or the like.
2. Description of the Prior Art:
A manual shift control system is jointly disclosed in U.S. Pat. Nos. 4,155,271, 4,170,148 and 4,197,760, all assigned to the Assignee of the present invention, utilizing input and output control shafts inserted through cutouts in respective input and output shift rails. The control shafts are rotatable in response to shift lever movement.
The control system in the above-cited prior art has an expanded "H" shift pattern to provide for nine forward speed ratios and one reverse speed ratio. One disadvantage to this type of control system is that it is difficult for the operator of the shift lever to always be aware of his position in the shift pattern.
The prior art also includes movable shift forks selectively engageable with the lower end of a shift lever. A plunger assembly is operably associated with the shift fork for resisting movement of the shift fork past a predetermined distance in a selected direction. Although in a five speed forward transmission the plunger assembly performs satisfactorily, it is believed that as the number of speed ratios increase, additional plunger assemblies necessary to provide variable resistance would make the transmission unduly complicated, cumbersome, inefficient and expensive to manufacture. Moreover, the engagement between the lower end of shift lever and the shift fork may not be practical when additional speed ratios are added.
SUMMARY OF THE INVENTION
The present invention solves the previously discussed problems and avoids the disadvantages by providing a transmission control system having a single control shaft carrying a plurality of cams capable of cooperation with associated cam follower cutouts in respective shift rails. The control shaft is rotatable and laterally movable in response to movement of a shift lever. The shift pattern for the control system is an expanded "H" pattern having a standard "H" portion so that the operator of the shift lever encounters increased resistance as he shifts away from the standard "H" pattern. The resistance increases by steps as the operator moves further away in the expanded "H" pattern.
The control shaft is spring biased to the standard "H" portion of the shift pattern. In the first embodiment, the right end of the control shaft is provided with an internal bore that receives a light blockout spring and a collar element which are both slidably mounted in the internal bore with the light blockout spring spaced between the terminal end of the internal bore and the collar element. The collar element is retained in the internal bore by a retaining ring to limit the extent of sliding movement of the collar element. Integrally connected to the collar element is an outwardly extending projection. The light blockout spring is compressed when the projection element encounters a portion of the control cover so that a first amount of resistance is provided to enable the operator to sense when the shift lever is shifted one pair of speed ratios to the right of the standard "H" portion of the shift pattern. Similarly, an internal bore is provided in the left end of the control shaft for receiving identically functioning parts to provide a first amount of resistance when the control shaft is shifted one pair of speed ratios to the left of the standard "H" portion of the control shaft.
Additionally in the first embodiment, a second amount of resistance greater than the first is provided when the control shaft is moved an additional pair of speed ratios to the right of the standard "H" portion of the shift pattern. The second additional amount of resistance is provided by a heavy blockout spring encompassed on the right end of the control shaft and spaced between a wall member relatively fixed on the shaft and a collar member slidably mounted on the shaft. The extent of sliding movement of the collar member is limited by a retaining member operably associated with the control shaft. The second additional amount of resistance is provided when the control shaft moves in a rightward direction so that the collar member also abuts a portion of the control cover to compress the heavy blockout spring.
Further features and advantages of this invention will be more readily understood by persons skilled in the art when following the detailed description in conjunction with the several drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-sectional view of a multiple input-multiple output nine speed transmission illustrating the first embodiment of the shift control system of the present invention;
FIG. 2 is a schematic illustration of the power paths through the transmission in each of the possible forward and reverse speeds for the transmission shown in FIG. 1;
FIG. 3 is a plan view of the transmission shown in FIG. 1 with the shift lever broken away;
FIG. 4 is a vertical cross-sectional view looking in the direction of arrows 4--4 in FIG. 3 with the shift control system of the FIG. 1 transmission positioned in a neutral position between the fourth and fifth gears;
FIG. 5 is an enlarged cross-sectional view looking in the direction of arrows 5--5 in FIG. 3 of the shift control system for the transmission shown in FIG. 1;
FIG. 6 is a diagrammatic view of output and input rail movement during a change in speed ratio for the shift control system of the first embodiment;
FIG. 7 is a schematic illustration of a transmission shift pattern for the first embodiment;
FIG. 8 is a detail view of an interlock disc shown operating in a shift rail cutout having a generally cross-like configuration;
FIGS. 9A-E is a detail view illustrating sequential cam movement of a rearward directional R 2 cam with initial delay shown operating in a modified cross-like rail cutout;
FIGS. 10A-E is a detail view illustrating sequential cam movement of a rearward directional R 1 cam with overtravel shown operating in a FIG. 8 type rail cutout;
FIGS. 11A-E is a detail view illustrating sequential cam movement of a bi-directional S 1 cam with overtravel having a downwardly disposed actuator portion shown operating in a FIG. 8 type rail cutout;
FIGS. 12A-E is a detail view illustrating sequential cam movement of a bi-directional O 2 cam with initial delay having an upwardly disposed actuator portion shown operating in a generally circular rail cutout having top cam follower portions;
FIGS. 13A-E is a detail view illustrating sequential cam movement of a bi-directional O 1 cam with overtravel having an upwardly disposed actuator portion shown operating in a FIG. 8 type rail cutout;
FIGS. 14A-E is a detail view illustrating sequential cam movement of a forward directional F 1 cam with overtravel shown operating in a FIG. 8 type cutout;
FIG. 15 is a cross-sectional view similar to FIG. 5 of a second embodiment of the present invention for a shift control system for a seven speed transmission;
FIG. 16 is a schematic drawing similar to FIG. 7 illustrating the shift pattern for a seven speed transmission shift control system of FIG. 15;
FIG. 17 is a cross-sectional view similar to FIG. 5 of a shift control system of a third embodiment of the present transmission for a six speed transmission;
FIG. 18 is a schematic drawing similar to FIG. 7 illustrating the shift pattern for a six speed transmission shift control system of FIG. 17;
FIGS. 19A-E is a detail view illustrating sequential cam movement of a bi-directional S 2 cam with initial delay having a downwardly disposed actuator portion and shown operating in a generally circular rail cutout having bottom cam follower portions;
FIG. 20 is a cross-sectional view similar to FIG. 5 of a fourth embodiment of the present invention for a shift control system for a five speed transmission;
FIG. 21 is a schematic drawing similar to FIG. 7 illustrating the shift pattern for a five speed transmission shift control system of FIG. 20;
FIGS. 22A-E is a detail view illustrating sequential cam movement of an F 2 cam with initial delay shown operating in a modified cross-like rail cutout with the lower section deleted; and
FIGS. 23A-E illustrates sequential cam movement of an O 1 cam with overtravel of a slightly different configuration than that of FIG. 13 having an upwardly disposed actuator portion in a generally circular rail cutout having top cam follower portions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Nine Speed Transmission
Referring now to the drawings in detail, the specific transmission 28 shown in FIG. 1, which can be used with the transmission control system of this invention, is generally the same as the transmissions shown in prior U.S. Pat. Nos. 4,000,662; 4,155,271; 4,170,148 and 4,197,760, all assigned to the Assignee of this invention. For ease of understanding, however, the structure and function of transmission 28, which has a plurality of constant-mesh change speed gears, is described below.
Transmission 28 includes a casing or housing 32, an input shaft 37 rotatably journalled therein and an output shaft 38 axially aligned with the input shaft and rotatably journalled relative to the input shaft and casing 32. A countershaft 30 is parallel to and vertically displaced below output shaft 38, while a dead shaft 34, parallel to countershaft 30, is fixedly retained in aligned bosses or stub walls 36 in casing 32.
Shaft 37 has a gear 40 affixed thereto or integral therewith, with gear 40 being in constant mesh with gear 42 rotatably journalled on countershaft 30. A conventional dog clutch 44, incorporating a known clutch lock to prevent jumping out of gear and a known synchronizer 45, is disposed on the hub of gear 42 and is arranged either to drivably connect gear 42 to countershaft 30 for conjoint rotation therewith, or to occupy a neutral position as shown in FIG. 1. A typical prior art synchronizer device is disclosed in U.S. Pat. No. 2,667,955, assigned to the assignee of the present invention.
Input shaft tubular portion 33, which is adjacent the inner axial end of gear 40, has either affixed thereto or integral therewith, one end of a sleeve 48 that coaxially surrounds output shaft 38, with sleeve 48 forming an extension of the input shaft.
Rotatably journalled on sleeve 48 is a gear 58 that is in constant mesh with a further gear 60 integral with or affixed to countershaft 30. Rotatably journalled on output shaft 38, adjacent to the inner end of sleeve 48, is a gear 64 that is slightly larger in diameter than gear 58 and in constant mesh with a gear 66 integral with or affixed to countershaft 30. Another conventional clutch 68, such as a dog clutch, also incorporating a clutch lock and a known synchronizer 69, is disposed on sleeve 48 between gears 58 and 64 and is arranged either to drivably connect gear 58 to sleeve 48, or to drivably connect gear 64 to sleeve 48, or to occupy a neutral position as shown in FIG. 1. Thus, basically, it is the function of clutch 68 to connect either of gears 58 and 64 for conjoint rotation with input shaft 37 via sleeve 48. Gears 40, 58 and 64, whose pitch circle diameters differ from one another in a well known manner are thus in constant mesh with gears 42, 60 and 66, respectively, with the utilization of clutches 44 and 68 thus providing three separate inputs to countershaft 30. The portion of transmission 28 described so far may be designated the "input" portion of this transmission.
Also journalled for rotation on output shaft 38 are gears 70, 72 and 74 whose pitch circle diameters differ from one another in a well known manner, with gears 70 and 74 being in constant mesh, respectively, with gears 76 and 78 affixed to or integral with countershaft 30. Gear 76, which has a greater axial extent than gear 70, is also in mesh with a gear 82 affixed to or forming part of a tubular reverse-idler shaft 80 which in turn is journalled for rotation on dead shaft 34. Gear 72 is in constant mesh with a gear 84 which is affixed to or forms a part of shaft 80.
A further conventional clutch 88, such as a dog clutch, and also incorporating a clutch lock and a known synchronizer device 90, is disposed on output shaft 38, intermediate gears 64 and 70, and is arranged to drivably connect either of these two gears to shaft 38 or to occupy a neutral position as shown in FIG. 1. A similar conventional clutch 92, incorporating a clutch lock and a known synchronizer 94, is disposed on output shaft 38, intermediate gears 72 and 74, and is arranged to drivably connect either of these gears to shaft 38 or to occupy a neutral position as shown in FIG. 1.
Basically, gears 64, 70, 72 and 74, together with gears 66, 76, 82, 84 and 78, may be described as constituting the "output" portion of transmission 28. It should be noted that gears 64 and 66 can alternately function both as input and output gears, as will be explained in more detail as this description progresses.
In operation, transmission 28 has nine forward speeds and as many as three reverse speeds, although not all of the three reverse speeds need be utilized. For example, only one reverse speed is utilized in the illustrated shift control system of the first embodiment. FIG. 2 is a schematic showing of the various power paths through transmission 28 in each of the possible forward and reverse speeds. As best seen in FIGS. 1 and 2, transmission 28 can be defined as having a first input via constant mesh gears 40 and 42, with the latter being adapted to be coupled to countershaft 30 via clutch 44, with countershaft 30 rotating in a direction opposite to that of input shaft 37. A second input is provided by constantly meshing gears 58 and 60, with the former being adapted to be coupled to input sleeve 48 via the forward (towards the input portion of the transmission) operative position of clutch 68, thereby causing the rotation of countershaft 30 in a direction opposite to that of input shaft 37. Yet another or third input is provided by constantly meshing gears 64 and 66, with the former being adapted to be coupled to input shaft sleeve 48 via the rearward (toward the output portion of the transmission) operative position of clutch 68, thereby rotating countershaft 30 in a direction opposite that of input shaft 37.
A first forward output from transmission 28 can be defined by constantly meshing gears 78 and 74, with the latter being adapted to be coupled to output shaft 38 via the rearward operative position of clutch 92, thereby rotating output shaft 38 in a direction opposite to that of countershaft 30. A second forward output is defined by constantly meshing gears 76 and 70, with the latter being adapted to be coupled to output shaft 38 via the rearward operative position of clutch 88, thereby rotating output shaft 38 in a direction opposite to that of countershaft 30. Yet another or third forward output is defined by constantly meshing gears 66 and 64, with the latter being adapted to be joined to output shaft 38 via the forward operative position of clutch 88, thereby again rotating output shaft 38 in a direction opposite to that of countershaft 30.
A reverse output is provided by constantly meshing gears 84 and 72, with the latter being adapted to be coupled to output shaft 38 via the forward operative position of clutch 92, thereby rotating output shaft 38 in the same direction as countershaft 30 (and in a direction opposite that of input shaft 37).
An analysis of FIG. 2 will show that by utilizing the first input (40,42) together with the first output (78,74) provides a first forward speed. Continuing the use of the first input but utilizing the second (76,70) or third (66,64) outputs will provide second or third forward output speeds. The second input (58,60) together with the first output provides a fourth forward speed, whereas the third input (64,66) with the first output provides a fifth forward speed. The second input together with the second output provides a sixth forward speed whereas the third input together with the second output provides a seventh forward speed. An eighth forward speed is provided by utilizing the second input together with the third output. The third input, which can also be the third output, provides a ninth or direct forward drive by utilizing clutch 68 to couple one side of the hub of gear 64 to input shaft sleeve 48 and by utilizing clutch 88 to couple the other side of the hub of gear 64 to output shaft 38.
Three reverse speeds are available by coupling any of the first, second or third inputs to the reverse output (84,72). In the illustrated example only the first input reverse speed is utilized.
Another way of defining the structure and function of transmission 28 is, as best seen in FIG. 2, that the first input is utilized in the first, second and third speeds as well as the first speed in reverse. The second input is utilized for the fourth, sixth and eighth speeds forward as well as the second speed in reverse. The third input is utilized for the fifth, seventh and ninth speeds forward. The first output is utilized for the first, fourth and fifth speeds forward, whereas the second output is utilized for the second, sixth and seventh speeds forward. The third output is utilized for the third, eighth and ninth speeds forward, while the reverse output is utilized for all of the possible reverse speeds.
A shift control system, generally designated by numeral 100 and best seen in FIGS. 4 and 5, for manually selecting any of the available power paths through the transmission, includes four shift forks or selector elements A, B, C and D. Shift forks B, C and D are rigidly attached to respective shift rails 107, 101 and 103 as will be explained in more detail as this description progresses. Shift fork A (best seen in FIG. 4) is pivotally connected at its midpoint 112 to casing 32 and has a socket portion 114 attached to a lug member 116 which is in turn is rigidly connected with shift rail 105. The lower end of shift fork A operatively engages clutch 44. Shift forks B, C and D operatively engage clutches 92, 88 and 68, respectively.
Shift control system 100 includes a control cover 118 whose control cover housing 120 fits over transmission 28 and is secured to transmission housing 32 by bolts 110. Parallel shift rails 101, 103, 105, and 107 are slidably supported in control over housing 120, for rectilinear movement relative thereto, on support pads 122. Shift rails 101 and 103 which are associated with shift forks C and D, respectively, may be denominated as the output shift rails since they serve to actuate output clutches 88 and 92, respectively. Similarly, shift rails 105 and 107, which are associated with shift forks A and B, respectively, may be denominated as the input shift rails since they serve to actuate input clutches 44 and 68, respectively.
Since clutches 68, 88, and 92 have a neutral position and an operative position on either side of neutral, each one of respective shift rails 107, 101 and 103 is provided with three notches 179 that can cooperate with a respective spring loaded detent 180 in order to position the respective shift rails to any one of these positions. See shift rail 101 illustrated in FIG. 4. Shift rail 105 is provided with only two notches 179 since clutch 44 has one operative position in addition to its neutral position.
Output shift rail 101 has a centrally located cutout 102 having a generally cross-like configuration which is symmetrical about its vertical and horizontal center lines. An identical cutout 104 is provided in output shift rail 103. See FIGS. 10, 11, 13 and 14. In FIG. 9 input shift rail 105 has a centrally located cutout 106 having a modified cross-like configuration symmetrical about its horizontal center line but not its vertical center line, see FIG. 12. Shift rail 107 has a circular cutout 108 having a top cam follower portion 109, which will be discussed in detail below.
Control cover housing 120 is provided with a top cover portion 150 having a general circular opening 152. Inserted in the opening 152 is a cap member 154 having a partial spherical opening 156 that is adapted to receive the mounting ball 188 of a shift lever 184. The mounting ball 188 is supported by a Belleville spring 153. A pair of spaced apart opposed pins 198 project into the opening 156 in cap member 154 and are received in respective slots 187 of mounting ball 188 to provide shift lever pivotal movement in the conventional manner. The cap member 154 has an outwardly flared flange 158 to receive the peripheral edge 124 of a closure member 126 which engages the shift lever 184 above the top cover portion 150. Closure member 126 is preferably made of a resilient material that will accommodate movement of the shift lever 184 and acts as a lubricant seal.
A control shaft 128 is rotatably journalled in control cover 120 and retained in spaced apart opposed bearing caps 130 that are attached to or integral with control cover 120, best shown in FIG. 5.
The control shaft 128 is provided with a centrally located cup shaped recess 132 which receives a lower shift lever assembly portion 185 of shift lever 184. The shift lever assembly portion includes a lower shift lever ball 186 received in a nylon annular bearing 189. The provision of the nylon annular bearing which abuts the outer surface of the cup shaped recess 132 reduces friction and vibration transmitted to the shift lever from the control shaft. Optionally, control cover housing 120 could also be of nylon construction to reduce noise and vibration.
With reference to FIG. 7, upward or forward movement of the handle of shift lever 184 will cause the control shaft 128 to rotate in a counterclockwise direction as viewed in FIGS. 8-14 through a predetermined arc, and downward longitudinal movement will cause the control shaft 128 to rotate in a clockwise direction through another predetermined arc. Additionally, lateral movement of the handle (not shown) of the shift lever in a leftward direction as viewed in FIG. 5 will cause the control shaft 128 to move axially to the right and rightward movement of the shift lever handle will cause the control shaft to move axially to the left.
A cylindrical projection 147 having an inner collar member 167 is internally mounted in a recessed bore 151 in the right outer end of control shaft 128. The collar portion 167 is prevented from escaping the bore 151 by a retaining ring 169 mounted in an annular groove in the bore 151. The projection 147 is urged outwardly by a light blockout spring 155. Similarly, a cylindrical projection 149 is mounted in a recessed bore 159 in the left outer end of control shaft 128 and has a collar portion 141 retained in the bore 159 by a retaining ring 173 mounted in a groove in the bore 159. The projection 149 is urged outwardly by a light blockout spring 157 sandwiched between collar portion 141 and the inner end of bore 159.
A relatively wide interlocking member 140 mounted on the right end of control shaft 128 is a hollow cylinder having a heavy blockout spring 175 mounted therein sandwiched beween the interior surface of left side wall 176 of interlocking member 140 and a collar member 177 slidably mounted around the control shaft 128 which is retained in the interior of hollow interlocking member 140 by a retaining ring 178 mounted in a groove in the interior surface of interlocking member 140.
In FIG. 5 the control shaft 128 is in a neutral position between 4th and 5th speed ratios (neutral position 133 as viewed in FIG. 7) so that right projection 147 is in slight contact with the interior surface of bearing cap 130. When the handle of the shift lever 184 is moved to its neutral position between the 6th and 7th speed ratios (neutral position 131 as viewed in FIG. 7) the control shaft 128 shifts to the left as viewed in FIG. 5 so that the outer end of cylindrical projection 149 is in slight contact with the interior surface of left bearing cap 130. Accordingly the fourth through seventh speeds may be considered to form the standard "H" pattern of the transmission. To move the shift lever 184 to a neutral position between the 8th and 9th speed ratios (neutral position 139 as viewed in FIG. 7) the handle (not shown) of the control lever 184 is moved to the right as viewed in FIG. 7 so that the control shaft 128 as viewed in FIG. 5 moves to the left so that light blockout spring 157 is compressed. The neutral position between the 8th and 9th speed ratios is reached when the light blockout spring 157 is fully compressed. To place the transmission 28 in the 2nd or 3rd speed ratios the handle of the shift lever 184 is moved to a neutral position between the 2nd and 3rd speed ratios (neutral position 135 as viewed in FIG. 7) so that the control shaft is moved to the right as viewed in FIG. 5 so that light blockout spring 151 is further compressed from its FIG. 5 position and heavy blockout spring 175 is not compressed further than its FIG. 5 position. The transmission 28 is in a neutral position between the first and reverse gears (neutral position 137 as viewed in FIG. 7) when extreme leftward movement of the shift lever handle as viewed in FIG. 7 occurs and in this condition both light blockout spring 151 and heavy blockout spring 175 are fully compressed. The varying resistance in the positioning of the handle of the shift lever 184 enables the operator to determine his position in the shift pattern in the expanded "H" shift pattern shown in FIG. 7.
The control shaft 128 is contained in the cutouts 106, 108, 102 and 104 in the shift rails and carries a plurality of cam members which selectively engage corresponding cam follower surfaces in the respective cutouts to axially shift the respective rails when a camming member undergoes rotation in a cutout due to longitudinal movement of the shift lever 184. Each cam is keyed on the control shaft in the usual fashion and the cams are held in place on the control shaft by a respective nut 171 threaded on either end of the outer surface of control shaft 128.
In FIG. 6 the input and output shift rail movement during a change in speed ratios is diagrammatically illustrated. Also shown in FIG. 6 are the neutral, first intermediate, second intermediate and final rotative positions of the control shaft 128 which correspond to the initial position of both shift rails, the beginning of input shift rail movement, the termination of output shift rail movement and the termination of input shift rail movement, respectively.
In the shift I portion of the FIG. 6 diagram the selected cam associated with the output shift rail cutout (further discussed below) is positioned in cutout 102 or 104 of respective output shift rail 101 or 103 for engagement with the cam follower surface of the cutout to shift the output shift rail in a chosen direction. Output shift rail movement controls the engagement of the corresponding output clutch in the conventional manner. Initial output shift rail movement causes the elimination of the clearances between the elements of the synchronizer and the conventional chamfered clutch teeth in the clutch in a known fashion. Further illustrated output rail movement operates the selected clutch to place the selected gears in driving engagement. The points of engagement past clutch teeth chamfers and full clutch engagement are shown in FIG. 6. The output rail does not undergo substantial movement during the latter portions of the control shaft 128 rotation since the cam positioned in the output rail cutout undergoes lost motion; i.e., its cam surfaces are not engaged with the cam follower surfaces of the cutout during latter portions of rotation of control shaft 128.
In the shift II portion of the FIG. 6 diagram the movement for an input shift rail such as input shift rail 105 or 107 is illustrated. The selected cam associated with input shift rail cutout (further discussed below) is positioned in the cutout of the selected input shift rail and undergoes lost motion during the first portions of rotation of control shaft 128. After a delay the first engagement between the cam positioned in the selected input shift rail and the camming surfaces of the input shift rail cutout actuates the corresponding input clutch which operates in the identical sequence as the output clutch discussed above. The latter portions of the output shift rail movement overlap with the initial portions of the input shift rail movement. The overlap occurs while the selected output clutch teeth are engaged at the point past the tooth chamfers to full engagement, while input shift rail movement is causing the elimination of the clearances between the synchronizer elements and the input clutching teeth.
With further reference to FIG. 7, the selected output and input shift rail is identified for each speed ratio. The arrows indicate the direction of movement of the lower portion of each respective fork A, B, C, D and associated clutch 44, 92, 88 and 68. Since forks B, C and D are connected rigidly to their respective shift rails 107, 101 and 103 they move in the same direction as their shift rails. Shift fork A is pivotally connected to shift rail 105, hence the upper portion of fork A moves in a direction opposite to its shift rail. The arrangement of cams on the control shaft 128 is determined by the desired shift lever pattern, such as that shown in FIG. 7 and the design of the transmission used therewith.
The two basic types of cam members mounted on the control shaft are double oscillating motion-single linear motion cams (unidirectional cams) and double oscillating motion-double linear motion cams (bidirectional cams). All cam members are adapted to cooperate with their associated shift rails to effect shift rail movement when the shaft 128 and cam members thereon are rotated from a neutral rotative position to a final rotative position. The unidirectional cams used in the present transmission 28 are denominated F cams and R cams. F cams are unidirectional cams which shift a corresponding shift rail in a forward direction towards the input portions of the transmission regardless of the direction of shaft rotation. Similarly R cams are unidirectional cams which shift the corresponding shift rail in a direction toward the rearward output portions of the transmission.
The subnumeral "1" found in F 1 and R 1 cams indicates initial shift cams with overtravel, i.e., cams undergoing lost motion during the latter portions of the rotation of control shaft 128. The subnumeral "2" found for example in R 2 cams indicates a cam with a delayed shift. Each of the cams have return portions for returning the associated shift rail from its shifted position back to its original position. The return portions of each subnumeral "1" cam are of the delayed shift type, while the turn portions of each of the subnumeral "2" cams are of the initial shift with overtravel type. It should be noted that all subnumeral "1" cams are output cams in the illustrated first embodiment while all subnumeral "2" cams are input cams. Therefore the selected output shift rail is shifted before the input shift rail when going from a neutral position to a speed ratio while the selected input shift rail is returned before the selected output shift rail when going from a speed ratio to a neutral position.
S cams are cams that shift the corresponding shift rail in the same direction as the lower shift lever ball 186 during shift lever movement. O cams shift corresponding shift rails in the opposite direction of the lower ball 186 during shift lever movement.
From the above description, it can be noted that the letter and subnumber of each cam will identify the type of cam (unidirectional or bidirectional) and the manner in which shift rail movement is accomplished.
FIGS. 8-14 illustrate the cam member-shift rail cutout interaction taking place during speed ratio changes in transmission 28. As an aid to understanding the invention, the different types of cam members in operation with associated cutouts of selected shift rails illustrated in FIGS. 8-14 will be discussed in detail below.
FIG. 8 illustrates a circular interlock disc member 138 positioned in the cutout 102 of input shift rail 101. The interlock member 138 during rotation of shaft 128 prevents the aligned shift rail 101 from being displaced since the outer peripheral surface of interlock member 138 is in abutment with outer corner portions 123 of the cam follower surface of the respective cutout. Similarly, interlock member 146 may be positioned in cutout 104 of output shift rail 103. Interlock members appear also in FIG. 5. As illustrated in FIG. 5 control shaft 128 also includes similar wide interlocking cylindrical members 140 and 148 disposed on opposite ends of control shaft 128 which are receivable in selected cutouts and operate in identical fashion as the interlock member 138 discussed above. In addition, interlocking surfaces 166 and 170 respectively, are machined on the control shaft 128 on either side of cup shaped recess 132 and also serve to lock associated shift rails during a speed ratio change in transmission 28.
FIGS. 9A-E illustrates an R 2 cam operating in cutout 106 of shift rail 105. FIG. 9C illustrates the position of the R 2 cam when the control shaft 128 is in its neutral position. The R 2 cam has top and bottom tooth portions 163 which are inclined away from right end wall portions 111 of cutout 106 when the control shaft 128 and R 2 cam mounted thereon is in its neutral FIG. 9C position. The clockwise movement of the R 2 cam from a FIG. 9C to a FIG. 9E position is accomplished by moving the handle of the shift lever in a downward longitudinal direction as shown in FIG. 7. Under clockwise rotation of the control shaft 128, the top tooth portion 163 comes in contact with top end wall 111 of the cutout cam follower surface as shown in FIG. 9D and further clockwise rotation of control shaft 128 will cause rail 105 to move in a rearward direction which because of the intervening lever moves clutch 44 forwardly. In FIG. 9E the control shaft has been rotated until the backside of lower tooth portion 163 abuts tooth locking portion 113 of the cam follower surface of cutout 106 and an upper corner portion 115 of the cam follower surface of cutout 106 is received in an upper notch return portion 117 of the R 2 cam. In the FIG. 9E position the control shaft is prevented from further clockwise rotational movement which is sensed by the operator manipulating shift lever 184 to indicate that the shift is completed. To change speed ratios the R 2 cam is rotated counterclockwise from the FIG. 9E position so that the upper notch return portion 117 in abutment with the upper corner portion 115 of cam follower surface of the cutout 106 will shift the shift rail 105 towards the forward input direction of the transmission 28 to return the shift rail to its FIG. 9D position then overtravel to return the control shaft to its FIG. 9C position. At this point the control shaft can be axially repositioned or further upward longitudinal movement of the shift lever 184 as shown in FIG. 7 will effect additional counterclockwise rotation of control shaft 128 to cause the lower tooth portion 163 of the R 2 cam to be placed in abutment with the lower end wall 111 of the cam follower surface of cutout 106 and further counterclockwise rotation of control shaft 128 will cause shift rail 105 to shift in a rearward direction until the R 2 cam is in the FIG. 9A position wherein the backside of upper tooth 163 is received in upper locking portion 113 of the outer cam follower surface at cutout 106 and lower corner portion 115 is received in lower notch return portion 117 of the R 2 cam. This moves rail 105 in a rearward output direction to move clutch 44 forwardly the same as previously described for cam movement between FIG. 9C and FIG. 9E. Then downward movement of the shift lever 184 to a neutral position of the shift lever as shown in FIG. 7 will cause the R 2 cam to shift the shift rail 105 back to its neutral 9C position from its 9A position due to contact between notch return portion 117 and locking surface 113.
In FIGS. 10A-E an R 1 cam operates in a cutout 102 or 104 to shift the shift rail 101 or 103 in a rearward output direction. The R 1 cam has upper and lower tooth portions 119 adjacent to upper and lower right end wall portions 121 of the cam follower surface of cutout 102 when the control shaft 128 is in its neutral position as shown in FIG. 10C. Movement of the shift lever 184 in a downward direction as viewed in FIG. 7 will cause the control shaft 128 to rotate in a clockwise direction so that the R 1 cam shifts the shift rail 101 in a rearward output direction until the cam-rail contact is disengaged due to the tip of the upper tooth 119 clearing the end wall 121 of the outer cam follower surface of cutout 102 as shown in FIG. 10D. Further lost motion clockwise rotation of the control shaft 128 will result in the R 1 cam being positioned in the 10E position wherein middle locking portion 144 of the R 1 cam is in contact with the right lower corner portion 123 of the outer cam follower surface of cutout 102 and the backside of lower tooth portion 119 is in contact with lower left end wall 121. To return the shift rail 101 or 103 to its neutral position, the control shaft is rotated in a counterclockwise direction wherein a trailing upper edge return portion 125 after an initial lost motion delay will come in contact with left upper end wall 121 to shift the shift rail 101 or 103 in a forward input direction until both the shift rail and the control shaft are returned to their FIG. 10C position. At this point the control shaft can either be axially repositioned or continued upward longitudinal movement of the control lever 184 as viewed in FIG. 7 will cause the control shaft 128 to continue to rotate in a counterclockwise direction such that lower tooth portion 119 adjacent to right lower end wall 121 will move the shift rail 101 or 103 in a rearward output direction until the tip of the lower tooth portion 119 passes by the right lower corner 123 of cutout 102 or 104. The operator of the shift lever 184 can feel that the shift is completed when the backside of the upper tooth 119 is in contact with left upper end wall 121 and the locking portion 144 is in contact with the right upper corner portion 123 of cutout 101 or 103. To return the R 1 cam from its FIG. 10A position to its FIG. 10C position, lower trailing edge return portion 125 after initial lost motion delay will come in contact with left lower end wall 121 to shift the shift rail 101 or 103 forward to its FIG. 10C neutral position.
In FIG. 11A-E an S 1 cam is positioned in cutout 102 of shift rail 101. The S 1 cam has a wide actuator portion 127 receivable in the bottom cross portion 129 of the outer cam follower surface of cutout 102. The neutral position for the S 1 cam is shown in FIG. 11C so that the S 1 cam is vertically disposed and the outer surfaces of the actuator portion 127 are adjacent to respective lower end walls 121 forming the lower cross portion 129. Clockwise rotation of control shaft 128 will cause the left edge of actuator portion 127 to press against the lower left end wall 121 of cutout 102 to cause the shift rail 101 to move in a forward input direction until the actuator portion 127 clears the lower left outer corner 123 of cutout 102 as shown in FIG. 11D. Further clockwise lost motion rotation will place the S 1 cam in FIG. 11E position where the S 1 cam is locked from further rotation since an upper left stop portion 161 is in contact with right upper corner portion 123 of cutout 102 and the central portion of the lower edge of actuator portion 127 is in contact with the left lower corner 123 of cutout 102. To return the output shift rail 101 to its neutral FIG. 11C position, the S 1 cam is rotated in a counterclockwise position so that the right stop portion 161 of actuator portion 127 becomes a return portion and after an initial post motion delay is in contact with lower right end wall 121 to shift the shift rail 101 or 103 in a rearward direction to return it to its FIG. 11C position. Continued counterclockwise rotation of the control shaft 128 and the S 1 cam mounted thereon will move the shift rail 101 or 103 from its FIG. 11C neutral position in a rearward output position until the S 1 cam is in the position shown in FIG. 11B so that the leading right edge of actuator portion 127 of the S 1 cam clears the lower right corner 123 of the cutout 102 or 104. Further lost motion rotation of the S 1 cam in a counterclockwise position will cause rightward locking portion 161 of the S 1 cam to contact the upper left corner 123 of cutout 102. Return of the S 1 cam from the FIG. 11A position to the FIG. 11C neutral position is simply the reverse of the above-described process.
In FIGS. 12A-E an O 2 cam is positioned in the cutout 108 of the shift rail 107. When the O 2 cam is in its neutral FIG. 12C position a single tooth portion 190 of the O 2 cam is spaced from the end walls 143 of a top cam follower surface 109 of cutout 108. Under clockwise rotation of control shaft 128 the O 2 cam moves from its FIG. 12C neutral position to its FIG. 12D position wherein initial contact is made between the tooth portion 190 and right end wall 143. Further clockwise rotation of control shaft 128 shifts the shift rail 107 in a rearward output direction until left locking notch-return portion 142 on the O 2 cam is in contact with the left corner surface 145 of top cam follower surface 109.
Counterclockwise rotation of control shaft 128 and the O 2 cam mounted thereon from the FIG. 12E position forwardly shifts the input shift rail 107 by the left locking notch-return portion 142 pressing against left corner 145 of cutout 108 until the notch clears the left corner 145 as shown in FIG. 12D. Further lost motion counterclockwise rotation of the O 2 cam returns it to the FIG. 12C position, where the control shaft 128 may be axially repositioned or rotated further in a counterclockwise direction so that tooth portion 190 abuts left end wall 143. Further counterclockwise rotation of the O 2 cam in cutout 108 from the FIG. 12B position to the FIG. 12A position effects the forward shifting of input shift rail 107. The shift is completed when right locking notch-return portion 142 contacts the right corner 145 of the cam follower surface 109.
The O 1 cam of FIGS. 13A-E is identical to the S 1 cam of FIGS. 11A-E except that the position of the actuator portion 127 is vertically reversed in the shift rail 101 or 103 and operates in the top cross portion 129. Clockwise rotation of the control shaft 128 now effects rearward movement of the shift rail 101 or 103 and counterclockwise rotation of the control shaft effects forward movement of the shift rail 101 or 103. Otherwise the operation of the O 1 cam of FIGS. 13A-E is identical to the operation of the S 1 cam in FIGS. 11A-E and like reference numerals are utilized for identical parts.
An F 1 cam is positioned in cutout 102 or 104 of rail 101 or 103 as shown in FIGS. 14A-E. The F 1 cam is a horizontally reversed R 1 cam of FIGS. 10A-E and its upper tooth portion 119 shifts the shift rail 101 or 103 in a forward input direction upon rotation of control shaft 128 in either a clockwise or counterclockwise direction. The reference numerals used in FIG. 10 to identify the R 1 cam are also repeated in FIG. 14 for identical parts. Otherwise the operation and function of the F 1 cam is identical to that of the R 1 cam.
Operation of Nine Speed Transmission
In FIG. 5 the control shaft 128 is in a neutral position between the fourth and fifth speed ratios so that an O 2 cam 134 is positioned in the cutout 108 of input shift rail 107 and a R 1 cam 136 is positioned in the cutout 104 of output shift rail 103. Additionally, interlock member 138 is positioned in cutout 102 of output shift rail 101 and relatively wide cylindrical interlocking member 140 is in cutout 106 of input shift rail 105. When the handle of shift lever 184 is moved upwardly to its FIG. 7 fourth speed ratio position, the control shaft 128 is rocked or rotated in a counterclockwise direction so that R 1 cam 136 rotates from its neutral FIG. 10C position through its FIG. 10B position to its FIG. 10A position so that output shift rail 103 and fork D are shifted in a rearward direction to actuate clutch 92 to place gears 74 and 78 in operation to provide the fourth speed ratio output. Additionally, O 2 cam 134 rotates from its neutral FIG. 12C position through its FIG. 12B position to its FIG. 12A position so that input shift rail 107 and fork B are shifted in a forward direction to actuate clutch 68 to place gears 58 and 60 in operation to provide the fourth speed ratio input. To change speed ratios, the handle of the shift lever 184 is returned to its neutral position 133 shown in FIG. 7 between the fourth and fifth speed ratios causing these selected shift rails and forks to return to their corresponding neutral positions.
To place the transmission 28 in its fifth speed ratio, the shift lever handle is moved from its neutral position 133 downwardly to its indicated fifth speed ratio position shown in FIG. 7. The R 1 cam 136 rotates from its FIG. 10C position through its FIG. 10D position to its FIG. 10E position so that output shift rail 103 and fork D are moved in a rearward direction to actuate clutch 92 to place gears 74 and 78 in mating engagement to provide the fifth speed ratio output. Additionally, O 2 cam 134 rotates from its neutral FIG. 12C position through its FIG. 12D position to its FIG. 12E position to shift both the output shift rail 101 and fork B in a rearward direction to actuate clutch 68 to place gears 64 and 66 in operation to provide the fifth speed ratio input.
As viewed in FIG. 7 to shift the transmission 28 from the neutral position 133 between the fourth and fifth speed ratios to a neutral position 135 between the second and third speed ratios, the shift lever handle is pivoted to the left so that the control shaft 128 moves one cam to the right as viewed in FIG. 5 to place S 1 cam 160 in the cutout 102 of output shift rail 101 and R 2 cam 162 in the cutout 106 of input shift rail 105. When the shift lever handle is in the neutral position 135, wide interlocking member 148 is in the cutout 108 of input shift rail 107 and interlock disc 146 is in cutout 104 of output shift rail 103.
When the shift lever handle is moved upwardly to its FIG. 7 second speed ratio position, the control shaft 128 rotates in a counterclockwise direction causing S 1 cam 160 to rotate from its neutral FIG. 11C position through its FIG. 11B to its FIG. 11A position so that output shift rail 101 and fork C are shifted in a rearward direction to actuate clutch 88 to place gears 76 and 70 in operation to provide the second speed output in the second speed ratio. Additionally, R 2 cam 162 rotates from its neutral FIG. 9C position through its FIG. 9B position to its FIG. 9A position so that input shift rail 105 is shifted in a rearward direction. However, due to the conventional pivotable connection of fork A to the housing 32 at the midpoint 112 of fork A, the lower end of fork A is shifted in a forward direction to actuate clutch 44 to place gears 40 and 42 in operation to provide the second speed ratio input. To change speed ratios, the shift lever handle is returned to its neutral position 135 causing the selected shift rails and forks to return to their corresponding neutral positions.
As viewed in FIG. 7, to place the transmission 28 in its third speed ratio, the handle of the shift lever 184 is moved from its neutral position 135 downwardly to its indicated third speed ratio position. The S 1 cam 160 rotates from its FIG. 11C position through its FIG. 11B position to its FIG. 11A position so that output shift rail 101 and fork C are moved in a forward direction to actuate clutch 88 to place gears 64 and 66 in operation to provide the third speed ratio output. Additionally, R 2 cam 162 rotates from its neutral FIG. 9C position through its FIG. 9B position to its FIG. 9A position to shift input shift rail 105 and fork A to actuate clutch 44 to place gears 40 and 42 in operation to provide the third speed ratio input.
As shown in FIG. 7, to place the transmission 28 in first or reverse speed ratios, the handle of the shift lever 184 is positioned at neutral position 137 so that the control shaft 128 is shifted two cams to the right as viewed in FIG. 5 to position R 2 cam 196 in cutout 106 of input shift rail 105 and O 1 cam 164 in cutout 104 of output shift rail 103. Additionally, relatively wide interlocking member 148 is still positioned in cutout 108 of input shift rail 107 and interlocking surface 166 is positioned in output shift rail 101.
When the handle of the shift lever 184 is moved upwardly to its reverse speed ratio position as shown in FIG. 7, the control shaft 128 is rotated in a counterclockwise direction so that O 1 cam 164 rotates from its neutral FIG. 13C position through its FIG. 13B position to its FIG. 13A position so that output shift rail 103 and fork D are shifted in a forward direction to actuate clutch 92 to place gears 72 and 84 in operation to provide the reverse speed ratio output. Additionally, R 2 cam 196 operates in an identical fashion as R 2 cam 162 as described in the description of the second speed ratio. To change speed ratios, the handle of the shift lever 184 is returned to its neutral position 137 between the reverse and first speed ratios.
As shown in FIG. 7, to place the transmission 28 in its first speed ratio, the handle of the shift lever 184 is moved from its neutral position 137 downwardly to its indicated first speed ratio position. The O 1 cam 164 rotates from its neutral FIG. 13C position through its FIG. 13D position to its FIG. 13E position so that output shift rail 103 and fork D are shifted in a rearward direction to actuate clutch 92 to place gears 74 and 78 in operation to provide the first speed ratio output. Additionally, R 2 cam 196 operates in identical fashion as R 2 cam 162 as described in the third speed ratio input to provide the first speed ratio input.
As shown in FIG. 7, to place the transmission 28 in its sixth or seventh speed ratios, the handle of shift lever 184 is moved to the neutral position 131 to shift the control shaft 128 one cam position to the left of that shown in FIG. 5 so that R 1 183 is positioned in cutout 102 of output shift rail 101 and O 2 cam 168 is positioned in cutout 108 of input shift rail 107. Additionally, interlocking surface 170 is positioned in cutout 104 of output shift rail 103 and relatively wide interlocking member 140 is positioned in cutout 106 of input shift rail 105.
When the handle of shift lever 184 is moved upwardly to its FIG. 7, sixth speed ratio position, the control shaft 128 and R 1 cam 183 mounted thereon rotates in a counterclockwise direction to rearwardly shift output shift rail 101 and fork C to actuate clutch 88 to place gears 70 and 76 in operation to provide the sixth speed ratio output. R 1 cam 183 functioning in the identical manner as R 1 cam 136 in cutout 104 of output shift rail 103 operates in the fourth speed ratio output described above. Additionally, O 2 cam 168 in cutout 108 of shift rail 107 provides the sixth speed ratio input in an identical fashion as O 2 cam 134 as described in the description of the fourth speed ratio input discussed above.
To place the transmission 28 in its seventh speed ratio, the handle of the shift lever 184 is moved from its neutral position 137 downwardly to its indicated seventh speed ratio position. R 1 cam 183 in cutout 102 of output shift rail 101 provides the seventh speed ratio output to actuate clutch 88 to place gears 70 and 76 in operation in an identical fashion as discussed above for the sixth speed ratio. Additionally, O 2 cam 168 in cutout 108 of input shift rail 107 operates in an identical fashion as O 2 cam 134 in cutout 108 of input shift rail 107 in the fifth speed ratio input as discussed above.
As shown in FIG. 7, to place the transmission 28 in the eighth or ninth speed ratios, the handle of the gear shift selector 184 is moved to the neutral position 139 so that the control shaft 128 is moved two cams to the left as shown in FIG. 5 so that O 2 cam 172 is positioned in cutout 108 of input shift rail 107 and F 1 cam 174 is positioned in cutout 102 of output shift rail 101. Additionally, locking surface 170 of control shaft 128 is positioned in cutout 104 of output shift rail 103 and relatively wide interlocking member 140 is positioned in cutout 106 of input shift rail 105.
When the handle of the shift lever 184 is moved upwardly to its FIG. 7 eighth speed ratio position, the control shaft 128 rotates in a counterclockwise direction so that F 1 cam 174 mounted thereon moves from its neutral FIG. 14C position through its FIG. 14B position to its FIG. 14A position so that output shift rail 101 and fork C are shifted in a forward direction to actuate clutch 88 to place gears 64 and 66 in operation. Additionally, O 2 cam 172 operates to provide the eighth speed input in an identical fashion as the fourth speed ratio input is provided by O 2 cam 134 discussed above.
To place the transmission 28 in its ninth speed ratio, the handle of the shift lever 184 is moved from its neutral position 139 downwardly to its indicated ninth speed ratio position shown in FIG. 7. The F 1 cam 162 rotates from its FIG. 14C position through its FIG. 14D position to its FIG. 14E position so that output shift rail 101 and fork C are shifted to actuate clutch 88 in a forward direction. Additionally, the O 2 cam 172 operates in the same fashion as described above for O 2 cam 134 in the description of the fifth speed ratio input to actuate clutch 68 in the rearward output direction. The effect of these operations is to lock the input and output shafts together for direct drive, through sleeve 48, clutch 68, gear 64 and clutch 88.
To summarize, the selected cams and interlocks are positioned in the cutouts of the respective shift rails to provide the speed ratios as follows:
______________________________________ OutputSpeed Input Shift Input Shift Output Shift ShiftRatio Rail 105 Rail 107 Rail 101 Rail 103______________________________________R-1 R.sub.2 Cam 196 Wide Inter- Interlocking O.sub.1 locking Surface 166 Cam 164 Member 1482-3 R.sub.2 Cam 162 Wide Inter- S.sub.1 Cam 160 Inter- locking locking Member 148 Member 1464-5 Wide Inter- O.sub.2 Cam 134 Interlocking R.sub.1 locking Member 138 Cam 136 Member 1406-7 Wide Inter- O.sub.2 Cam 168 R.sub.1 Cam 183 Inter- locking locking Member 140 Surface 1708-9 Wide Inter- O.sub.2 Cam 172 F.sub.1 Cam 174 Inter- locking locking Member 140 Surface 170______________________________________
The Seven Speed Transmission
Referring now to FIGS. 15 and 16, a second embodiment of the present invention is illustrated and is essentially identical to the first embodiment of FIGS. 1-14 except that the fourth and fifth speed ratio are eliminated so that a seven speed transmission is provided. Like components are denoted by the same reference numerals as in FIGS. 1-14 except that 100 series numerals are expressed as 200 series numerals.
The modifications to transmission 28 shown in FIG. 1 necessary to accommodate the control system 200 shown in FIG. 15 are not set forth in detail since such modifications would be obvious to one skilled in the art. In the control system shown in FIG. 15, O 2 cam 134 and interlock member 138 used in the fourth and fifth speed ratios in the first embodiment are eliminated. An additional interlocking member 2246 is mounted on the control shaft 228 adjacent the leftward portion of cup-shaped recess 232 and operates in the cutout of shift rail 203 when the control shaft 228 is positioned in the second or third speed ratios or the neutral position 235 between the second and third speed ratios as viewed in FIG. 16.
The direction of movement of the lower portion of each selected fork is shown in FIG. 16. It should be noted that the reverse through third speed ratios shown in FIG. 16 are identical to that shown in FIG. 7 while the fourth through seventh speed ratios in FIG. 16 are identical to the sixth through ninth speed ratios shown in FIG. 7.
The recessed bore 159 of control shaft 128 and the parts mounted therein shown in FIG. 5 of the first embodiment are eliminated in the second embodiment since the elimination of the fourth and fifth speed ratios of the first embodiment renders light blockout spring 157 unnecessary.
The Six Speed Transmission
Referring now to FIGS. 17-19, a third embodiment of the present transmission is shown and is similar to the first embodiment of the control system except as discussed below. Accordingly, like components are denoted as in FIGS. 1-14 except that they are expressed in 300 series notation.
In the third embodiment a transmission control system 300 for a six speed transmission is disclosed that has two reverse speeds, R1 and R2 (optional). A multiple input-multiple output transmission for the control system of the third embodiment is not illustrated but a known conventional transmission could easily be adapted to cooperate with this transmission control system.
The transmission control system 300 includes output shift rails 3301 and 303 and input shift rail 3307. Forks B, C, and D are associated with the respective shift rails as in the first embodiment. It should be noted that pivotally mounted fork A is not included in the third embodiment so all the forks move in the same direction as their respective rails as illustrated in FIG. 18. The cutout for rail 3301 has a bottom cam follower portion 3309 similar to the cutout 108 of shift rail 107 in the first embodiment. The input rail 3307 has a cutout similar to cutout 102 or 104 of output shift rails 101 or 103 of the first embodiment. The cutout for the output shift rail 303 is identical to cutout 104 of output shift rail 103 of the first embodiment.
S 2 cams 381-382 are utilized in this embodiment as illustrated in FIG. 19. S 2 cam 381 is positioned in cutout 3302 of shift rail 3301 during the third and fourth speed ratios and S 2 cam 382 during the fifth and sixth speed ratios. The cutout 3302 has a bottom cam follower portion 3309 capable of receiving tooth portion 3390 of each S 2 cam.
In its neutral FIG. 19C position, the actuator portion 3390 of the S 2 cam positioned in the cutout 3302 is spaced from the end walls 3343 of the cam follower surface on the cutout 3302. Under clockwise rotation of control shaft 328, each S 2 cam moves from its neutral FIG. 12C position to its FIG. 12D position wherein initial contact is made between the actuator portion 3390 and left end wall 3343. Further clockwise rotation of the control shaft 328 shifts the shift rail 3301 in a forward input direction until right locking notch-return portion 3342 on cam O 2 is in contact with the right corner surface 3345 of lower cam follower surface 3309.
Counterclockwise rotation of control shaft 328 and the S 2 cam mounted thereon from the FIG. 19E position forwardly shifts the output shift rail 3301 by means of the left locking notch-return portion 3342 pressing against left corner 3345 of cutout 3302 until the notch clears the left corner 3345 as shown in FIG. 19D. Further lost motion counterclockwise rotation of the S 2 cam returns it to the FIG. 19C position where the control shaft 328 may be axially repositioned or rotated further in a counterclockwise rotation so that actuator portion 3390 abuts right end wall 3343. Further clockwise rotation of the S 2 cam in the cutout 3302 from the FIG. 19B position to the FIG. 19A position effects the rearward shifting of output shift rail 3301. The shift is completed when the left locking notch-return portion 3342 contacts the left corner 3345 of the cam follower surface 3309.
In the R1, R2, first and second speed ratios, the output rail is shifted before the input rail as was done in the first and second embodiments. However, in the third through sixth speed ratios the input rail is shifted before the output rail. This demonstrates that the transmission control system of the present invention is flexible and can be modified to conform with transmissions of various configurations.
The shift control system 300 operates essentially as the control system 100. In FIG. 18 the shift pattern of the shift control system of FIG. 17 is illustrated. Neutral position 393 between the third and fourth speed ratios corresponds with the position of the control shaft 328 in FIG. 17. When the handle (not shown) of shift lever 384 is shifted to the right as viewed in FIG. 18 to the neutral position 394 between the fifth and sixth speed ratios, the control shaft moves one cam to the left as viewed in FIG. 17. Similarly when the handle of the shift lever is moved to the neutral position 392 between the first and second speed ratios, the control shaft 328 moves one cam to the right and moves yet another cam to the right when the shift lever is moved to neutral position 391 between the R1 and R2 speed ratios.
The third through sixth speeds may be considered to comprise the standard "H" portion of the shift pattern shown in FIG. 18. The right end of control shaft 328 is provided with a bore 351 that receives light blockout spring 355 and associated parts. A heavy blockout spring 375 and associated parts is received in the interior of interlock member 340 to enable the operator to distinguish the additional speed ratios in an identical fashion as the two pairs of leftward adjacent speed ratios are distinguished in the first embodiment.
Except as noted all cams function as previously discussed with respect to the first embodiment. However, the shift rails are repositioned in the transmission and the cams are rearranged on the control shaft 328 to present the third embodiment six speed shift control system of the present invention. The selected cams are positioned in the cutouts of respective shift rails to provide the speed ratios as follows:
______________________________________Speed Input Shift Output Shift Output ShiftRatio Rail 3307 Rail 3301 Rail 303______________________________________R1-R2 O.sub.2 Cam 3368 Locking F.sub.1 Cam 395 Surface 3661-2 O.sub.2 Cam 3372 Locking R.sub.1 Cam 3383 Surface 3663-4 F.sub.1 Cam 3374 S.sub.2 Cam 381 Wide Inter- locking Member 3405-6 R.sub.1 Cam 3336 S.sub.2 Cam 382 Wide Inter- locking Member 340______________________________________
The Five Speed Transmission
Referring now to FIGS. 20-23, a fourth embodiment of the present invention is illustrated and is similar to the first embodiment of the control system except as otherwise discussed below. Accordingly, like components are denoted as in FIGS. 1-14 except that they are expressed in 400 Series notation.
In the fourth embodiment a transmission control system 400 for a five forward speed transmission is disclosed that has one reverse speed. A multiple input-multiple output transmission for the control system of the fourth embodiment is not illustrated but known conventional transmissions could easily be adapted to cooperate with this transmission control system.
The transmission control system 400 includes output shift rails 4401 and 403 and input shift rail 407 having an auxiliary rail 4405 rigidly attached thereto so that the auxiliary rail 4405 and input shift rail 407 move in unison when a selected cam rotates in the cutout of input shift rail 407 or the cutout of auxiliary rail 4405. It should be noted that the cams are positioned on the control shaft 428 so that a cam is not simultaneously positioned in the cutouts of input shift rail 407 and auxiliary rail 4405 during any of the speed ratios shown in FIG. 21. The cutout for input shift rail 407 is similar to the cutout 108 of rail 107 shown in the first embodiment. The cutout 4406 for auxiliary rail 4405 is a modified version of the cutout 106 of shift rail 105 in that the cutout is vertically reversed and the bottom portion is eliminated. The output shift rail 4401 has a generally circular cutout 4402 having a top cam follower portion 4409 as shown in FIG. 23.
FIGS. 22A-E illustrates an F 2 cam utilized in this embodiment operating in cutout 4406 of auxiliary rail 4405. FIG. 22C illustrates the position of the F 2 cam when the control shaft 428 is in its neutral position. The F 2 cam has top and bottom tooth portions 4463 which are inclined away from left end wall portions 4411 of cutout 4405 when the control shaft 428 and the F 2 cam mounted thereon is in its neutral FIG. 22C position. The movement of the F 2 cam from its FIG. 22C position to a FIG. 22E position is accomplished by moving the handle of the shift lever in a downward longitudinal direction as shown in FIG. 21 to cause clockwise rotation of the control shaft 428. Under clockwise rotation of the control shaft 428, the bottom tooth portion 4463 comes into contact with the bottom end wall 4411 of the cutout cam follower surface as shown in FIG. 22D and further clockwise rotation of the control shaft 428 will cause the auxiliary rail 4405 and shift rail 4407 connected thereto to move in a forward input direction. In FIG. 22E the control shaft has been rotated until the backside of upper tooth portion 4463 abuts tooth locking portion 4413 of the cutout 4406 and lower corner portion 4415 of the cam follower surface of the cutout 4406 is received in a lower notch-return portion 4417.
To change speed ratios the F 2 cam is rotated counterclockwise from the FIG. 22E position so that the lower notch-return portion 4417 in abutment with the lower corner portion 4415 of the cam follower surface of the cutout 4406 will axially shift the auxiliary rail 4405 towards the rearward output direction of the transmission to return the auxiliary rail 4405 to its FIG. 22C neutral position, thus also returning the shift rail 407 to its neutral position.
At this point the control shaft could be axially repositioned or further upward longitudinal movement of the shift lever 484 as shown in FIG. 21 will effect additional counterclockwise rotation of the control shaft 428 to cause the upper tooth portion of the F 2 cam to be placed in abutment with the upper end wall 441 of the cam follower surface of the cutout 4406 and further counterclockwise rotation of the control shaft 428 will cause auxiliary rail 4405 to shift in a rearward direction until the F 2 cam is in its FIG. 22A position wherein the backside of lower tooth portion 4463 is received in lower locking portion 4413 of the outer cam follower surface of cutout 4406 and the lower corner portion 4415 is received in the lower notch-return portion 4417 of the F 2 cam. Similarly, downward movement of shift lever 484 to a neutral position of the shift lever as shown in FIG. 21 will cause the F 2 cam to shift the auxiliary rail 4405 back to its neutral FIG. 22C position due to the contact between notch-return portion 4417 and locking surface 4413.
O 1 cam 4464 which is positioned in cutout 4402 of output shift rail 4401 has a slight different configuration and is positioned in a differently configured cutout but operates in identical fashion as the O 1 cam in the first embodiment illustrated at FIG. 13.
In FIG. 21 the shift pattern of the shift control system 400 is illustrated. Neutral position 492 between the second and third speed ratios corresponds with the position of control shaft 428 in FIG. 20. When the handle (not shown) of shift lever 484 is shifted to the right as viewed in FIG. 21 to the neutral position between the fourth and fifth speed ratios, the control shaft moves one cam to the left than that viewed in FIG. 20. Similarly, when the handle of the shift lever is moved to neutral position 491 between the reverse and first speed ratios the control shaft moves one cam to the right from that viewed in FIG. 20.
As shown in FIG. 21 the second through fifth speeds may be considered to comprise the standard "H" shift pattern. The right end of control shaft 428 is provided with a bore 451 that receives light blockout spring 455 and associated parts to enable the operator to sense the additional first and reverse speed ratios in an identical fashion as the leftward adjacent pair of speed ratios is sensed in the first embodiment.
Except as noted all cams function as previously discussed with respect to the first embodiment. However, the shift rails are repositioned in the transmission and the cams are rearranged on the control shaft 428 to present the fourth embodiment five speed shift control system of the present invention. The selected cams are positioned in the cutouts of the respective shift rails to provide the speed ratios as follows:
______________________________________ Input Aux.Speed Auxiliary Shift Rail Output Shift Output ShiftRatio Rail 4405 407 Rail 4401 Rail 403______________________________________R-1 F.sub.2 Cam 482 -- O.sub.1 Cam 4464 Interlock Member 44462-3 -- O.sub.2 Cam 4468 Interlock R.sub.1 Cam 4436 Member 44384-5 -- O.sub.2 Cam 4472 Interlocking F.sub.1 Cam 4474 Member 481______________________________________
From the foregoing, it is believed that those familiar with the art will readily recognize and appreciate the novel concepts and features of the present invention. While the invention has been described in relation to only four embodiments, numerous variations, changes and substitutions of equivalence will present themselves to persons skilled in the art and may be made without necessarily departing from the scope and principles of this invention. As a result, the embodiments described herein are subject to various modifications, changes and the like, with the scope of this invention being determined solely by reference to the claims appended hereto.
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A manual shift transmission having multiple input and output portions is provided with a control having input and output shift rails. A laterally movable control shaft extends axially through cutouts in respective shift rails and carries cams adapted to cooperate with cam follower surfaces on corresponding cutouts to effect rectilinear movement of the shift rails upon rotation of the control shaft. The cams are arranged on the shaft so that the shaft may be positioned to place respective cams in register with the input and output shift rails while all other cams are out of register with the rail cutouts. The shift movement of respective output and input shift rails is overlapped during the rotation of the control shaft to decrease the throw of the shift lever. The control shaft is spring biased to provide variable resistance in response to movement of a control lever to enable the operator to determine his position in the shift pattern of the transmission.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a method and system using delay signals to reduce or eliminate interference between paths in a communication network, in particular an electronic circuit.
[0003] 2. Description of the Related Art
[0004] Communication networks, in particular communication networks on integrated circuits, have numerous paths carrying signals from one device to other devices. Multiple paths that are placed near one another can lead to problems related to coupling and capacitative interference. The situation becomes most problematic when multiple paths carrying signals that transition or switch at the same time, run parallel to a single path switching in the opposite direction.
[0005] Coupling effects do not have a noticeable effect upon signals that are switching in the same direction. In a digital signal transmission, the rise of the signal from a driver connected to a path is not affected by signals from the other paths switching in the same direction. Coupling effects, however, can have an effect upon the paths whose signals switch in the opposite direction. In particular coupling effects lead to slower rise times of path signals. To compensate for slower rise times, path driver power is increased. Path drivers are required to provide additional power to compensate for a slower rise time in order to get signals out and to achieve proper signal level and timing requirements.
[0006] In certain designs, neutral paths such as ground paths, also known as shield lines, are available and placed between aggressors and victim paths, effectively shielding the opposite switching paths from one another. Shield lines typically serve no function but are merely used to shield the victim path. The use of neutral paths or shield lines also leads to design considerations and network architecture constraints in laying out paths. Adding shield lines further adds to an increase in the space of the network. In an integrated circuit, minimizing size is highly desirable, and adding non-functional shield lines becomes counter productive to meeting the goal of minimizing size.
SUMMARY OF THE INVENTION
[0007] In one embodiment, a method of transmitting a signal is disclosed. The method includes sensing adjacent signals and delaying certain adjacent signals until switching or transition takes place with the other adjacent signal or signals.
[0008] In certain embodiments, various number signal groups including two-signal, three-signal, and five-signal groups sense and delay for particular signals. Signals that are adjacent to more than one signal are delayed in the event that any or all of the adjacent signals simultaneously switch with the particular signals.
[0009] In certain embodiments, a separate sensing and delay circuit is provided. Along with buffers, the sensing and delay circuit provides a delay signal to the buffers in the event that adjacent signals switch simultaneously, thus delaying an adjacent signal.
[0010] In other embodiments, the method assigns priorities to transmitted signals. Signals that have a lower priority compared to signals with a higher priority are delayed until the higher priority signals are switched. In certain embodiments, a delay pulse is sent to by the higher priority signal or signals to the lower priority signal or signals.
[0011] The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the present invention, as defined solely by the claims, will become apparent in the non-limiting detailed description set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the figures designates a like or similar element.
[0013] [0013]FIG. 1A is a diagram illustrating the use of inverter delays to avoid coupling interference.
[0014] [0014]FIG. 1B is a timing diagram illustrating a three-signal group with delay provisioning.
[0015] [0015]FIG. 1C is a timing diagram illustrating a five-signal group with delay provisioning.
[0016] [0016]FIG. 1D is a timing diagram illustrating a five-signal group with delay provisioning when three adjacent signals switch simultaneously.
[0017] [0017]FIG. 1E is a timing diagram illustrating a five-signal group with an extended delay when initial delay results in simultaneously switching with an adjacent signal.
[0018] [0018]FIG. 2 is a block diagram illustrating use of a sensing and delay circuit and buffers to transition a three-signal group.
[0019] [0019]FIG. 3 is a flow diagram illustrating transition of adjacent signals for a three-signal group.
[0020] [0020]FIG. 4 is a block diagram illustrating use of a sensing and delay circuit and buffers to transition a five-signal group.
[0021] [0021]FIG. 5 is a flow diagram illustrating transition of adjacent signals for a five-signal group.
[0022] [0022]FIG. 6 is a block diagram of three and five signal groups with shield lines.
[0023] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail, it should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION
[0024] The following is intended to provide a detailed description of an example of the invention and should not be taken to be limiting of the invention itself. Rather, any number of variations may fall within the scope of the invention which is defined in the claims following the description.
[0025] Introduction
[0026] The present invention provides a method and apparatus for avoiding or minimizing coupling interference in adjacent paths in a communication network by sensing transitioning (switching) instances of adjacent paths and delaying a signal from transitioning while adjacent signal(s) transitions. Coupling interference is avoided between the adjacent signal paths by assuring sufficient time differences exist between the transitioning of the adjacent signals. A signal transitions (switches) without coupling interference from a simultaneously switching adjacent signal.
[0027] Delay Signals
[0028] [0028]FIG. 1A is a diagram illustrating the use of inverter delays to avoid coupling interference. Signal 1 100 is an adjacent signal to Signal 2 105 . Signal 2 105 is an adjacent signal to Signal 3 110 . In order to avoid coupling interference, in particular when Signal 1 100 , Signal 2 105 , and Signal 3 110 are switching, a delay is provided in the form of an inverter 115 along the path of Signal 2 105 . Switching of a signal takes place on either a rising or falling edge of the signal. In this particular example, the signals are digital signals representing either a “1” or “0” value. Signal 2 105 is restored later along the transmission line is by inverter 120 . In other words, the signal 2 105 is inverted once again to restore the original transmitted value prior to inverter 115 . The path of inverted Signal 2 105 is presented by path length 125 . Because of the delay from inverter 115 and 120 , a non-coupling zone 125 is provided assuming signal 2 105 is not delayed such that signal 2 105 switches at the same time as signal 1 100 and/or signal 3 110 . Within non-coupling zone 130 , there is a small likelihood of coupling interference between signals 100 , 105 and 110 , assuming that delay to Signal 2 105 would not cause Signal 2 105 to couple with Signal 1 100 and Signal 3 110 .
[0029] [0029]FIG. 1B is a timing diagram illustrating a three-signal group with delay provisioning. Signal 1 100 , signal 2 105 , and signal 3 110 are part of a three-signal group with signal 2 105 placed between signal 1 100 and signal 3 110 . Whenever signals 100 and 105 , or signals 105 and signal 110 switch simultaneously, in this particular example the three signals 100 , 105 , 110 are switching at time T 1 115 , a delay is performed by delay logic 120 . Delay logic 120 provides a sufficient delay to signal 2 105 in order to prevent simultaneous switching with signal 1 100 and/or signal 3 110 . Signal 2 105 switches at time T 2 125 . The delay is a d 130 . Delay d 130 can be a predetermined period of time or any amount of time sufficient to prevent simultaneous switching with signal 2 105 and adjacent signal 1 100 and signal 3 110 . The delay avoids any coupling interference in the event that signal 2 105 is an opposite switching signal to either signal 1 100 and/or signal 3 110 .
[0030] [0030]FIG. 1C is a timing diagram illustrating a five-signal group with delay provisioning. Signal 1 100 , signal 2 105 , signal 3 110 , signal 4 135 and signal 5 140 are adjacent to one another in order. In this particular example, all five signals are switching at the same time, time T 1 115 . In this particular embodiment, delay logic 120 delays signal 1 100 , signal 3 110 , and/or signal 5 140 whenever simultaneous switching occurs with adjacent signal 2 105 and/or signal 4 135 . Signal 2 105 and signal 4 135 are never delayed, and are allowed to switch at their initial switching time, in this case time T 1 115 . In this example, signal 1 100 , signal 3 110 , and signal 5 140 are delayed and switch at time T 2 125 . The delay d 130 can be a predetermined period or any sufficient amount of time that prevents simultaneous switching of signals. The delay avoids any coupling interference between adjacent simultaneously switching signals.
[0031] [0031]FIG. 1D is a timing diagram illustrating a five-signal group with delay provisioning when three adjacent signals switch simultaneously. In this particular example, signal 1 100 and signal 5 140 simultaneously switch at time T 1 115 . Signal 1 100 and signal 5 140 are far enough apart that simultaneously switching does not affect the respective signals. Signal 2 105 , signal 3 110 , and signal 4 135 simultaneously switch at time T 3 145 . In order to avoid any coupling interference, specifically if signal 3 110 is an opposite switching signal to signal 2 105 and/or signal 4 135 , delay logic 120 delays signal 3 110 . Signal 2 105 and signal 4 135 , in this embodiment, are never delayed and switch at their respective original switch time T 3 145 . Signal 3 110 is switched at time T 4 150 , providing a delay of d 130 . Delay d 130 can be a predetermined period of delay of any amount of delay sufficient to avoid simultaneously switching of adjacent signals. FIG. 1E is a timing diagram illustrating a five-signal group with an extended delay when initial delay results in simultaneously switching with an adjacent signal. In this particular embodiment of the invention, signal 2 105 and signal 4 135 are never delayed, and always switch at their respective original switch times, in this example signal 2 105 switches at time T 1 115 and signal 4 135 switches at time T 3 145 . Signal 1 100 , signal 3 110 , and signal 5 140 switch at time T 1 115 , the same time that signal 2 105 switches. Delay logic 120 senses that adjacent signal 1 100 and signal 3 110 switch at the same time as signal 2 105 , therefore a delay is provided to signal 1 100 and signal 3 110 . Signal 1 100 now switches at time T 3 145 , the same time as signal 4 135 , however the two signals are far enough removed from one another to avoid any coupling interference. Signal 3 110 would also be delayed to time T 3 145 , however, this condition would result in signal 3 110 switching at the same time as signal 4 135 . Delay logic 120 therefore provides for signal 3 110 to be further delayed to time T 5 155 . The adjusted delayed timing diagram prevents adjacent signals from switching at the same times and avoids coupling interference when adjacent signals are switching opposite one another.
[0032] Sensing and Delay Logic
[0033] [0033]FIG. 2 is a block diagram illustrating use of a sensing and delay circuit and tri-state buffers to transition signals. Signals 100 , 105 , and 110 are monitored by sensing and delay circuit 200 . Sensing and delay circuit 200 receives sense signals 205 , 210 , and 215 respectively from signal 1 100 , signal 2 105 , and signal 3 110 . Sensing and delay circuit 200 determines if signal 2 105 switches at the same time as signal 1 100 and/or signal 3 110 . If signal 2 105 switches at the same time as either adjacent signal 1 100 or adjacent signal 3 110 , signal 2 105 is delayed. In this example, buffers 220 and 230 are buffers to match the delay of tri-state buffer 225 when there is no simultaneous switching. Tri-state buffer 225 provides for three possible values: a value of 0, 1, or a high impedance value. A signal may be switching on the rising edge, therefore a value of 1 is associated with it. A signal that is switching on the falling edge has a value of 0. A signal that has been delayed or is awaiting transition from sensing and delay circuit 200 maintains its binary signal value. The use of sensing and delay circuit 200 along with buffers 220 , 225 , and 230 assure that signal 1 100 and 3 110 are always immediately passed through. Signal 2 105 is immediately passed through without delay unless signal 2 105 switches at the same time as Signal 1 100 or Signal 3 110 . Since signal 1 100 is far enough removed from signal 3 110 , possibility of coupling interference between signal 1 100 and signal 3 110 is minimal.
[0034] [0034]FIG. 3 is a flow diagram illustrating transition of adjacent signals for a three signal group. Sensing and delay circuit 200 receives signals 100 , 105 , and 110 , step 300 . Signals 100 and 105 are sensed at the same time, step 305 . Simultaneously signals 105 and 110 are also sensed with one another at the same time, step 310 . A determination is made if signals 100 and 105 are switching at the same time, step 315 . A determination is also made whether signals 105 and 110 are switching at the same time, step 320 . If the condition is true for either steps 315 or 320 , then signal 2 105 is delayed, step 325 . If steps 315 and 320 are both determined to be “no,” then signal 2 105 is not delayed, step 330 .
[0035] [0035]FIG. 4 is a block diagram illustrating use of a sensing and delay circuit and buffers to transition a five-signal group. Buffer 400 is used for signal 1 100 . Buffer 405 is used for signal 2 105 . Buffer 410 is used for signal 3 110 . Buffer 415 is used for signal 4 135 . Buffer 420 is used for signal 5 140 . Buffers 400 , 410 , and 420 are tri-state buffers that receive delay signals from sensing and delay circuit 425 . A received delay signal to the respective buffer tri-states the respective signals. In this particular example delay signal 430 is provided to buffer 420 . Delay signal 435 is provided to buffer 410 . Delay signal 440 is provided to buffer 400 . Sensing and delay circuit 425 , in this embodiment, includes three separate circuit or logic blocks: sensing and delay circuit A 445 ; sensing and delay circuit B 450 ; and sensing and delay circuit A 455 . The respective sensing and delay circuits can include digital, analog, and/or combined circuits that sense and hold signals and trigger respective tri-state buffers 400 , 405 , 410 , 415 , and 420 . In this particular embodiment, sensing and delay circuit A 445 senses signal 1 100 through sense signal 460 and signal 2 105 through sense signal 465 . Sensing and delay circuit B 450 senses signal 2 105 through sense signal 470 , signal 3 110 through sense signal 475 , and signal 4 135 through sense signal 480 . Sensing and delay circuit A 455 senses signal 4 135 through sense signal 485 and signal 5 140 through sense signal 490 . The use of sensing and delay circuit 425 , in particular sensing and delay circuit 450 and tri-state buffer 410 to delay signal 3 , provides a uninterrupted continuous delay. Delay signal 435 is provided to tri-state buffer 410 whenever the delay actually is required to take place. This prevents separate delay glitches that can cause aberrations in signal transmission.
[0036] [0036]FIG. 5 is a flow diagram illustrating transition of adjacent signals for a five-signal group. FIG. 5 specifically illustrates the logic involved in the block diagram and the sensing and delay circuits of FIG. 4. As in a three-signal group, contention is provided for a five-signal group using a sensing and delay circuit or similar logic. Other multiple signal groups can also make use of such logic and similar sensing and delay circuit (logic). In this example, the sensing and delay circuit receives five signals, signals 1 , 2 , 3 , 4 and 5 , step 500 . Signals 1 , 2 , 3 , 4 , and 5 in order are adjacent to one another in the group. In other words, signal 1 is adjacent to signal 2 ; signal 2 is adjacent to signal 3 ; signal 3 is adjacent to signal 4 ; and signal 4 is adjacent to signal 5 . Signals 1 and 2 are sensed with one another, step 505 . Signals 2 and 3 are sensed with one another, step 510 . Signals 3 and 4 are sensed with one another, step 515 . Signals 4 and 5 are sensed with one another, step 520 . A determination is made as to whether Signals 1 and 2 are transitioning (switching) at the same time, step 525 . If step 525 is determined to be “yes” then Signal 1 is delayed, step 530 . If step 525 is determined to be “no” then Signal 1 is not delayed, step 535 . A determination is made as to whether adjacent signals 4 and 5 are transitioning at the same time, step 540 . If step 540 is determined to be “yes” then signal 5 is delayed, step 545 . Since signal 3 is the middle signal of the five-signal group and is directly adjacent to signals 2 and 4 , signal 3 is delayed if signal 3 transitions at the same time as either signal 2 or signal 4 . A separate determination is made as to whether signals 2 and 3 are transitioning at the same time, step 555 . Another determination is made as to whether signals 3 and 4 are transitioning at the same time, step 560 . If either step 555 or step 560 is “yes,” signal 3 is delayed, step 565 . If both step 555 and step 560 are “no” then Signal 3 is not delayed, step 570 .
[0037] [0037]FIG. 6 is a block diagram of three and five signal groups with shield lines. Sensing and delay circuits can be placed before, after, or in signal drivers. The signal drivers transmitting the signal after delay is provided to the signal. In order to maximize the use of sensing and delay circuits, signals are grouped together and use a single sensing and delay circuit. Signal group 600 is a group of three signals. Signal group 605 is another group of three signals. Groups 600 and 605 can be placed near one another; however, to prevent any coupling between the adjacent signals of the two groups, a shield line 610 is added. Signals in groups 600 and 605 can be placed relatively near one another through the use of the sensing and delay circuits, however some protection and spacing is provided by way of shield line 610 . In a similar manner groups of five-signal groups can be provided as illustrated by signal groups 615 and 620 , and separated by shield line 625 . Other multiple number signal groups can be provided, and variations are possible in the use of various groupings of signals and shield lines. Groupings and use of shield lines are dependent on the circuit or network architecture that is desired.
[0038] Although the present invention has been described in connection with several embodiments, the invention is not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as can be reasonably included with in the scope of the invention as defined by the appended claims.
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A method of transmitting adjacent signals is disclosed. Sensing is performed on signals in the group and adjacent signals are either switched or delayed if the adjacent signals are switching at the same time. The method is used in networks where coupling and capacitance effects are possible.
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FIELD OF THE INVENTION
The present invention is directed to a pump apparatus and, more particularly, to a pump apparatus for filtering a liquid, preferably by reverse osmosis.
BACKGROUND OF THE INVENTION
Osmosis is a natural phenomenon whereby a solution containing low solids passes through a semi-permeable membrane into a solution having greater solids concentration. Osmotic flow ceases and reaches equilibrium when the pressure in the higher solids solution equals the osmotic pressure for the membrane. Reverse osmosis occurs when a pressure greater than the osmotic pressure forces water molecules through the semi-permeable membrane in the reverse direction.
Reverse osmosis devices are known for making potable water from sea or poluted water. The conventional reverse osmosis system consists of a pump, a reverse osmosis module and a back pressure valve. The pump supplies water to the module. The semi-permeable membrane of the module element converts 10 to 20 percent of the unpurified solution to potable water. The remaining 80 to 90 percent of the solution passes to the pressure valve, which is set to maintain a pressure in the module somewhat greater than the osmotic pressure of the overflow solution. From the back pressure valve, the solution goes to waste.
Thus, generally, the energy in overflow solution from a conventional system is lost. A number of devices, however, are known for recovering that energy. In a classic device the overflow solution impinges on a Pelton wheel attached to the pump or the pump drive motor.
Other energy recovery devices are of the energy exchange type where the energy in the overflow solution is transferred to a new solution. Generally, these devices, as in U.S. Pat. No. 3,791,768, use opposed cylinder piston pumps in which the pistons are driven by the overflow concentrate of a reverse osmosis module. The energy required to pump the portion of new solution, equal in volume to the permeated or purified water, and to overcome the friction in the system, is supplied by a mechanically-driven, auxiliary pump.
Other energy exchange devices employ a single reciprocating plunger. A recent such device is shown in U.S. Pat. No. 4,187,173. In that device, a hand lever is used for the power assist. The device includes a spool-type, three-way valve, the stem of which protrudes from the housing and is parallel with the plunger rod and is attached to the hand lever. In the downstroke, the valve stem attachment to the hand lever is the fulcrum. When the stroke of the lever reverses, the fulcrum shifts from the valve stem to the plunger rod. The plunger rod remains stationary in order to serve as the new fulcrum because of a hydraulic lock on the system.
Although useful, the device of U.S. Pat. No. 4,187,173 has a number of drawbacks. For example, during startup the hydraulic lock does not exist and priming is difficult. In addition, seals to the atmosphere are required at both ends of the valve spool thereby leading to potential for leaks and failure. Most significantly, however, is that the stroke loss due to the shifting of the three-way valve and the stroke loss due to the limited angle through which the lever may be effectively manipulated results in a larger and heavier pumping unit than should be the case and than is acceptable for many uses.
SUMMARY OF THE INVENTION
An important object of this invention is to provide a reciprocating plunger pump capable of circulating a large volume of unpurified solution through a reverse osmosis module with an energy input only slightly more than that required to pump the product purified water at the overambient osmotic pressure.
Another important object of the invention is to provide a pump that can be driven mechanically or by hand lever by simply applying force to the plunger rod.
Yet another object is to incorporate a hydraulic actuated, three-way valve that opens fully inlet and vent ports resulting in minimum pressure drop at the ports.
Still another object is to minimize stroke loss due to shifting the three-way valve.
A further object is to provide a button on the protruding stem, connected to the shuttle of the three-way valve, that can be depressed during start up to hold the vent open to the driving chamber on the rod side of the plunger thereby allowing the reverse osmosis module to fill with solution at a rapid rate while compressing air in the module to make it a very effective accumulator to maintain pressure in the module during suction strokes.
To this end, the apparatus of the present invention includes a pump housing to which a cylindrical canister for a reverse osmosis element is attached. The pump housing has a three-step bore to receive the body, the fresh water tube and the overflow tube of the reverse osmosis element. Opposite the three-step bore, the pump housing has a cylindrical bore for receiving the plunger and rod, with the rod extending through a cylinder cap. The closed end of the cylinder bore has a pair of counter bores to take the inlet and outlet valve assemblies, respectively. A passage is provided between the outlet valve bore and the outer bore for the reverse osmosis element.
A manifold is attached to one side of the pump housing. The manifold has openings at one end for unpurified solution inlet and unpurified concentrate outlet. The manifold has an opening at an opposite end for fresh water outlet. A passage is provided in the manifold to connect the inlet opening with the inlet valve of the pump cylinder. The manifold has an other passage to connect the fresh water tube of the reverse osmosis element with the fresh water opening. In addition, the manifold has a cylindrical bore to receive a shuttle having a stem that passes through a plug at the open end of the bore. The ends of the bore are in fluid communication with opposite ends of the pump cylinder. The shuttle serves as a spool to create a three-way spool valve. The closed end of the shuttle bore or a button on the shuttle stem and a projection on the bore plug serve as stops to limit movement of the shuttle. The ratio of the shuttle stem diameter to the main shuttle diameter should be the same as the ratio of the plunger rod diameter to the plunger diameter so that the volume of solution in the plunger cylinder combined with that in the valve bore on either side of the shuttle remains constant during any shift of the shuttle from stop to stop. This allows the pump stroke to be reversed at any point and to be reversed smoothly. Because the diameter of the shuttle is small compared to the diameter of the plunger, very small movement of the plunger causes the shuttle to shift. Consequently, very little pump stroke is lost in shifting the three-way valve.
A central land on the shuttle has an axial length a little more than three times the width of a center port which is in fluid communication with the rod end of the cylinder. Shuttle travel is limited by stops while shifting the land to either side of the center port. The shuttle has a reduced main diameter between the central land and packing lands at opposite ends of the shuttle. The axial length of the reduced diameter portions are such that the pressure port on one side of the central land which is in fluid communication with pressurized concentrate from the reverse osmosis element and the vent port on the other side of the central land which communicates with the waste port of the device are both open to respective cavities formed by the reduced diameter portions of the shuttle regardless of location of the shuttle with respect to the stops and the center port.
Thus, on a pressure stroke of the plunger, the shuttle is shifted to a position directing pressurized concentrate to the driving chamber or the rod side of the plunger. As a result of the shuttle stem being resisted only by atmospheric pressure, the shuttle moves all the way to the bottom stop, opening the central port fully. On the suction stroke of the piston, the shuttle is shifted to a position allowing the solution in the driving chamber to evacuate. As a result of the pressure differential across the shuttle created by the sudden acceleration in the inlet water system the instant the central port cracks open, the shuttle moves all the way to the top stop, again opening the center port fully. Until the indicated instant, new solution is not drawn into the pumping chamber due to the constant volumes on opposite sides of the shuttle.
It is noted that either a mechanical, power driven, reciprocating mechanism or a hand lever may be used to drive the plunger rod of the present pump.
Thus, each of the objects of the present invention are accomplished. Furthermore, the objects are particularly advantageous with respect to function and lead to structure unknown in the art. Although the advantages and objects have been pointed out, however, they are further explained and may be better understood by reference to the following drawings wherein a preferred embodiment is illustrated and thereafter described in detail.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of pump apparatus in accordance with the preferred embodiment of the present invention;
FIG. 2 is a side elevational view of the apparatus of FIG. 1;
FIG. 3 is a top end view of the apparatus of FIG. 1;
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3;
FIG. 6 is a composite view in section showing the functional relationship of the various elements; and
FIG. 7 is an elevational view of the pump apparatus as driven by rotary shaft.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIGS. 1-3, a pumping apparatus in accordance with the present invention is designated generally as 10. Apparatus 10 includes a housing 12 with a cylindrical tube 14 attached at a bottom end 16. A hand lever 18 is pivotally connected at end 26 by nut and bolt combination 28 to one end of a set of links 30 which are pivotally connected at the other ends to a bracket portion 34 of a cylinder cap 90 that is secured to the housing 12 by cap screws 92. At a spaced distance from links 30, lever 18 is attached to yoke 22 with nut and bolt combination 20 and with nut and bolt combination 32 to plunger rod 35. Yoke 22 pivots at 20 while links 30 pivot at both 28 and the lever attachment to bracket portion 34. A manifold 36 is attached to side 38 of housing 12 with a plurality of machine screws 40. Although it iss preferable that manifold 36 be separate and attached to housing 12, it is understood that the two elements could be an integral unit.
Housing 12 is preferably made from square bar stock and machined appropriately. Cylindrical tube 14 is permanently attached to housing 12 by weld or other conventional attachment mechanism. As shown in FIGS. 4 and 6, a ferrule 44 is permanently attached to the bottom end portion 46 of tube 14 by weld or other conventional attachment mechanism. A plug 48 (see fIG. 4) fits within the end of tube 14 and ferrule 44 and is held in place with a snap ring 50. An O-ring 52 or other similar mechanism provides a pressure seal between plug 48 and cylinder 14.
A three step bore in bottom end 16 of housing 12 is designed to receive filter element 54, preferably a reverse osmosis element. Outer step 56 receives body 58 of element 54. Intermediate step 60 receives fresh water tube 62 of element 54. Inner step 64 receives overflow concentrate tube 66 of element 54.
Top end 24 of housing 12 has a bore for forming a pumping cylinder 68 for plunger 70. Plunger 70 separates cylinder 68 into a pumping chamber on the valve side of the plunger and a driving chamber on the rod side of the plunger. As indicated hereinbefore, rod 35 is attached to plunger 70, the combination of which is reciprocated, as shown in FIGS. 1-3, by hand lever 18 about fulcrum 28. The bottom end of cylinder 68 has a pair of counterbores 72 and 74, as shown most clearly in FIG. 6, which receive intake and exhaust valve assemblies 76 and 78. Each valve assembly 76 and 78 includes a seat 80, a poppet 82, a valve spring 84 and a spring retainer 86 assembled together in a conventional fashion. A plate 91 held with screws (not shown) hold valve assembles 76, 78 in place. Rod 35 passes through a cylinder cap 90 (which is held in place by cap screws 92) and an appropriate seal assembly 94 dynamically seals rod 35 with respect to cap 90.
A number of reverse osmosis elements are commercially available, and the present invention is not directed to any particular type. A typical reverse osmosis element 54, however, includes a semi-permeable membrane 96 wrapped about fresh water tube 62. Body 58 has end members 98 and 100 at either end of membrane 96. End member 98 fits snugly and is sealed at U-cup 102 to outer step 56. An end spacer member 104 has a plurality of vanes extending outwardly and downwardly to provide a snug fit for the bottom end of element 54 with cylinder 42 and cap 48. An impermeable retaining sleeve 106 encircles membrane 96 to keep it in place. End members 98 and 100 are spaced from fresh water tube 62 with a plurality of legs 108. Overflow concentrate tube 66 is spaced apart from fresh water tube 62 by the different diameter bores of intermediate step 60 and inner step 64 at one end and an enlarged diameter portion 110 of concentrate tube 66 at the other end. Water passes through membrane 96 to enter fresh water tube 62. Water which passes through legs 108 of end member 98 and along membrane 96 flows to concentrate tube 66.
In addition, although a typical reverse osmosis element has been described with respect to the preferred embodiment, it is understood that the present invention is equally applicable for other typess of filtration to the full extent of the claims.
Manifold 36 is preferably made of rectangular cross-section bar stock. Manifold 36 has three tapped openings 112, 114, and 116 for receiving hose fittings 11, 120, and 122. Opening 112 is the seawater or polluted water or unpurified water inlet. Opening 112 communicates with intake valve 76 through passagee 124 in manifold 36 and passage 126 in housing 12. Opening 114 is the waste port. Opening 114 is in fluid communication with vent port 170 of bore 146 and also is in fluid communication with adjustable relief valve 128. Relief valve 128 is conventional and includess ball 134 held against restriction 136 by spring 138 retained by threaded bushing 140. Opening 116 is the fresh water outlet. Opening 116 is in fluid communication with fresh water tube 62 through passage 142 in manifold 36 and passage 144 in housing 12.
Manifold 36 also has a cylindrical bore 146 forming a chamber that takes a shuttle 148 with an attached stem 150 that passes through a plug 152 in the open end of the bore. At its outer end, stem 150 is fitted with a button 154. The closed end of bore 146 is in fluid communication with the closed end of cylinder 68 through first end port 156 in manifold 36 and passage 158 in housing 12. The end of bore 146 next to plug 152 is in fluid communication with the rod side of piston 70 through second end port 162 in manifold 36 and passage 164 in housing 12. A center port 166 in bore 146 communicates through passage 168 in housing 12 with passage 164 to chamber 160 on the rod side of plunger 70. A vent port 170 connects cavity 187, defined as the annular space between the reduced diameter portion 178 of shuttle 148 and the wall of bore 146 with waste or outlet port 114. A pressure port 172 connects cavity 189, defined as the annular space between the reduced diameter portion 176 of shuttle 148 and the wall of bore 146 with the passage 130 which is in fluid communication with the concentrate side of element 54 by means of passage 132. Relief valve 128 is disposed between passage 132 and opening 114.
Shuttle 148 has a center land 174, the length of which is slightly more than three times the width of center port 166. Shuttle 148 has reduced diameter portions 176 and 178 on opposite sides of center land 174. Reduced diameter portion 176 extends between center land 174 and a packing land 180 at the bottom end of shuttle 148. Reduced diameter portion 178 extends between center land 174 and packing land 182 at the top end of shuttle 148 for internal attachment with stem 150. The length of reduced diameter portions 176 and 178 are such that the cavities formed between them and the wall of bore 146 are always open to pressure port 172 and vent port 170, respectively, regardless of the position of shuttle 148. Shuttle 148 moves from an uppermost location wherein the lower end 184 of plug 152 forms a stop for land 182 to a lowermost position wherein the upper end 186 of plug 152 forms a second stop with button 154 making the contact. Alternatively, button 150 may be spaced from end 186 with the inner end of bore 146 functioning as the second stop.
It is understood that various static and dynamic seals are needed throughout apparatus 10. Such seals are conventional. For example, the packings on shuttle 146 and piston 70 are fluorocarbon rings backed up with O-rings. The seals on rod 35 are double lipped type seals. A U-cup is preferred for sealing element 54 to housing 12. The various static seals are O-rings.
It is further understood that, although hand lever 18 is disclosed as the preferred embodiment for driving pump apparatus 10, a mechanical drive as shown in FIG. 7 could as well be applied too rod 35. In addition, multiple cylinders and plungers and driving mechanisms could be designed to operate in conjunction with one another to function the present or multiple equivalents of the present use device.
The mechanical drive of FIG. 7 shows a rotary shaft 200 connected through a crank member 202 by link 204 to rod 34' of apparatus 10'. Bracket 206 supports shaft 200 with bearings or a bearing surface within bosses 210. Bracket 206 is attached to apparatus 10' at cap screws 92'. Bracket 206 includes a pair of spaced walls 208 having bosses 210 attached to the outer sides of each. Crank 202 is fixedly attached to shaft 200 and rotates with it. Link 204 is fastened to crank 202 pivotably with pin 212 while link 204 is fastened pivotably to rod 34' with pin 214.
It is noted that the following relationships exist between various elements of apparatus 10. The ratio of the cross sectional area of plunger rod 35 to the cross sectional area of piston 70 is the same as and determining the recovery ratio of the reverse osmosis element 54. The recovery ratio is the percentage of fresh water as compared with total water pumped per stroke. Also, the ratio of the diameter of stem 150 of shuttle 148 to the diameter of land 182 must be the same as the ratio of the diameter of plunger rod 35 to the diameter of plunger 70 to maintain a constant volume of water on opposite sides of plunger 70 and shuttle 148 during the hydraulic shifting of shuttle 148.
In operation, seawater or other impure or unpotable water is directed from a source to hose fitting 118. During an upstroke or suction stroke of plunger 70, intake valve 76 is opened and feed water is inducted through passages 124 and 126 and intake valve 76 to pumping cylinder or chamber 68. On reversal of force applied to lever 18, plunger 70 begins a pumping stroke. During the downstroke or pumping stroke, feed water is forced through outlet valve 78 and passage 188 to outer bore 56 and along legs 108 of end member 98 to membrane 96. The water continues to flow along membrane 96 and legs 108 of end member 100 to overflow concentrate tube 66 and passage 132, 130, and 172 to cavity 189, and through port 166 and passages 168 and 164 to chamber 160. It is noted that in the preferred embodiment hand lever 18 pivots about a fulcrum at nut and bolt combination 28 so as to drive plunger 70 at all times.
By applying finger pressure of about 15 psi to button 154 during the initial reciprocations of plunger 70, first air and then feed water will be drawn through intake valve 76 and forced into the system at the full displacement ratio of the plunger pump until a pressure of about 80 psi is developed. At that pressure level, the level of solution in element 54 is above concentrate output tube 66 and the air trapped in the system makes the various passages and cavities an effective accumulator. On each pumping stroke, feed fluid pressurizes in the pumping chamber and at the lower end of shuttle 148 in bore 146. On the pumping stroke that exerts enough pressure through passage 158 and port 156 to overcome the finger pressure on button 154 and shuttle 148, shuttle 148 will shift to the upper end of chamber 146 thereby closing center port 166 to vent port 170 and opening center port 166 to pressure portt 172 to allow pressurization of driving chamber 160 during a downstroke of plunger 70. That is, impure concentrate water from tube 66 will flow through passages 132 and 130 to pressure port 172 and the cavity 189 around reduced diameter portion 176 of shuttle 148 to center port 166 and passages 168 and 164 to chamber 160. Since the pressurized water is on the back side of plunger 70, only sufficient force to develop a higher pressure than that already present in the system need be applied by hand lever 18. That is, due to the equalization of the unit pressure on both sides of plunger 70, the pressure stroke needs to provide a force on a rod 35 only slightly greater than the unit pressure times the cross sectional area of plunger rod 35.
It is noted that center port 166 opens fully because of the difference in force on the ends of shuttle 148 as a result of shuttle stem 150 passing through to atmosphere. It is also noted that a very small movement of plunger 70 shifts shuttle 148 because the cross sectional area of shuttle 148 is only, for example, about one-tenth the area of plunger 70. In such a circumstance, the required movement of plungwer 70 is about 0.031 inches for moving shuttle 148 about 0.312 inches. Therefore, only a very small portion of plunger stroke is lost in shifting the valve shuttle.
On upstrokes following the overcoming of the finger pressure on button 154, liquid in chamber 160 on thwe rod side of plunger 70 is forced into bore 146 to shift shuttle 148 to where button 154 stops against end 186 of plug 152. Again, a very small movement of plunger 70 causes shuttle 148 to shift. During the shift, the combined volume of the liquid in the system from one side of plunger 70 and shuttle 148 to the other remains constant since the ratio of the diameter of shuttle stem 150 to the diameter of the shuttle lands is the same as the ratio of the diameters of rod 35 to plunger 70. Thus, movement of plunger 70 causes shuttle 148 to shift since the cavities at the same ends of each are in fluid communication with one another. As center land 174 moves past center port 166, the closed system including element 54 is isolated between land 174 and closed exhaust valve 78. As soon as port 166 cracks open to vent port 170 through cavity 187, water on the rod side of plunger 70 depressurizes and vents, while shuttle 148 opens fully due to the suction developed at the bottom end of the shuttle.
With repeated strokes, a volume of solution equal to the displacement of plunger rod 35 is added to the closed system with each stroke. Pressure in the system continues to build until it exceeds the osmotic pressure of membrane 96. At that point, fresh water migrates through membrane 96 into fresh water tube 62 and passages 144 and 142 to tapped port 116 for connection to a fresh water receptacle. The pressure in the closed system floats to where the fresh water produced is equal to the downstroke displacement of plunger rod 35 during each reciprocation. Adjustable relief valve functions to prevent rupturing pressures from being exerted on membrane 96 if there is a clogging of membrane 96.
Certain critical relationships for apparatus 10 have been indicated. Other features of the structure, however, could have a number of equivalents. Consequently, although details of all elements of the structure have been set forth, it is understood that the presently preferred embodiment is exemplary. Therefore, changes made, especially in matters of shape, size, arrangement, and combinations of components and assemblies, to the full extent extended by the general meaning of the terms in which the appended claims are expressed, are understood to be within the principle of the present invention.
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The present invention is directed to pump apparatus for purifying water. The apparatus includes a housing containing a reciprocating plunger pump with a permanently attached filtering module preferably containing a reverse osmosis element. A manifold with a hydraulic actuated shuttle which serves as the spool for a three way valve is attached to the pump housing. The valve provides alternate pressurization and exhaust for the rod side of the piston. The pump may be operated by a hand lever or by power mechanism.
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BACKGROUND OF THE INVENTION
This invention relates to epitaxial layers of II-VI semiconductor compounds doped with nitrogen, and more particularly relates to a method of producing such layers having improved dopant concentration and improved crystallinity.
As is known, semiconductors are characterized as either n-type or p-type, depending upon whether the predominant carriers in the material are electrons or holes. As is also known, semiconductors can be rendered n-type or p-type by substituting impurity atoms (dopants) for atoms of the host lattice which have a different valence. Donor-type impurities are those which give electrons, and thus render the host material n-type, while acceptor-type impurities are those which receive electrons, and thus render the host p-type.
Successful doping to obtain or enhance n-type or p-type conductivity depends not only on the ability to introduce a sufficient amount of the proper dopant into the semiconductor material, but also upon the ability to position the dopant atoms in the proper substitutional sites within the material's crystal lattice where they can give or receive electrons.
Dopants which do not readily assume the proper substitutional sites in sufficient number can be activated, i.e., converted to donors or acceptors, e.g., by a thermal anneal of the doped semiconductor material.
Another important consideration is the presence of other impurities in the semiconductor material which are, or are capable of assuming, an opposite conductivity type than that intended, thus compensating the effect of the dopant. Thus, it is actually the net donor or acceptor concentration which determines the overall conductivity of the material.
Semiconductors which can easily be rendered n-type or p-type, such as Si. from Group IVA of the Periodic Table, and GaAs, a III-V compound, so-called because it is made up of elements from Groups IIIA and VA of the Periodic Table, can be converted to devices such as diodes by doping adjacent regions p- and n-type to form pn junctions.
II-VI compounds such as ZnS and ZnSe are of interest for such devices because of their relatively wide band gaps. For example, being able to form a doped junction in an epitaxial layer of ZnSe could result in a blue-emitting LED or laser.
However, in practice, it has proved extremely difficult to obtain stable p-type ZnSe epitaxial layers. While a sufficient amount of dopant can usually be introduced into the layers, it is either difficult to convert sufficient numbers of the dopant atoms into acceptors, or the acceptors are unstable. For example, lithium-doped epitaxial layers of ZnSe can be converted to p-type material (defined herein as a material having a net acceptor concentration greater than 1x10**14 acceptors or holes per cc)., but lithium is unstable because of its tendency to diffuse, even at relatively low temperatures.
Nitrogen would be a more stable acceptor than lithium, and can be doped into ZnSe in situ in high concentrations (10**19/cc) using metal organic chemical vapor deposition (MOCVD). However, only a small fraction of it (up to 1×10**14/ cc) can be activated.
Greater success has been achieved using chemical beam epitaxy (CBE). That is, starting with an as-grown dopant concentration of about 10**19, a net acceptor concentration in the range of 10**16 to 10**17 has been achieved. However, the technique requires relatively expensive equipment and the conversion efficiency is relatively low.
A problem encountered in the MOCVD of N-doped ZnSe using NH 3 as the dopant species is the limitation in the active acceptor concentration achievable due to the relative stability of NH 3 at the growth temperature. NH 3 is expected to decompose into NH 2 ,NH . . . (NHx) with each subsequent species being present in decreasing concentration. Also the possibility of HxN-NHx dimer formation is likely. Increasing the decomposition of NH 3 by using higher growth temperatures results in a decrease in the sticking coefficient of these species on the growth surface. Active Nitrogen acceptor is incorporated when the Hx from the NHx species which arrive at the surface is removed, possibly due to the attraction of CH 3 from the metalorganic (MO) species. Attempts to increase the concentration of NHx by increasing the flow of NH 3 in the growth chamber results in the degradation of crystal quality of the epi layer, probably due to NH 3 reacting with the Se MO precursor.
Dopants are usually activated by a carefully controlled thermal treatment such as a furnace anneal, which allows the dopant ions to relax into the correct substitutional sites in the host lattice, and/or results in the removal of a species, such as H, which tends to passivate the dopant.
Unfortunately, such annealing, while necessary to achieve activation, often results in degradation of the epi layer, for example, by interdiffusion across the boundary surfaces of the layer.
Rapid thermal annealing has been employed in combination with a diffusion-limiting capping layer, in order to minimize degradation of the epi layer during activation. See commonly assigned copending U.S. patent application Ser. No. 851,452, filed Mar. 16, 1992.
However, it would be preferable to produce a highly doped epi layer having a greater proportion of the dopant in an active or nearly active condition, so that subsequent activation by annealing could be carried out at lower temperatures, for shorter times, or both, to achieve the same or even greater amounts of activation, with less degradation of the epi layer.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to produce highly doped epitaxial layers of II-VI semiconductor compounds in which the proportion of the dopant in an active or nearly active condition is improved.
It is another object of the invention to produce such layers in which the crystallinity of such doped epi layers is improved.
In accordance with the invention, such doped layers are produced by metalorganic chemical vapor deposition (MOCVD) using the technique of flow modulation epitaxy (FME) and using nitrogen (N) as the dopant and ammonia (NH 3 ) as the dopant growth species.
As used herein, the term FME means the growth of an epi layer by the introduction into the growth chamber of one or more of the growth species at timed intervals, rather than introducing all of the species simultaneously. As used herein, the term growth species means a compound or intermediate of a cation or anion of the II-VI compound, or the dopant ion, which species decomposes or disassociates thermally or chemically during growth to yield the ion.
In accordance with the invention, it has been discovered that the proportion of dopant in an active or nearly active state in an as-grown epi layer of a II-VI semiconductor compound, as well as the crystallinity of the layer, can be improved by separating the growth and doping processes. Accordingly, in its broadest aspects, the invention comprises growing a doped epi layer of a II-VI semiconductor compound, such as ZnSe, by FME, in which the anion growth species and NH 3 , are introduced alternately at timed intervals, so that substantially either one or the other, but not both, are present in the growth chamber at any time, and in which the cation species is substantially always present in the growth chamber with the NH 3 .
In a preferred embodiment of the invention, the anion species is present substantially alone in the growth chamber for a timed interval before the cation species and the NH 3 are introduced, so that the growth surface is substantially devoid of the cation during the doping interval.
While not completely understood, and therefor not relied upon to define the invention, the following explanation is offered as an aid to understanding the benefits of the above procedure, which are thought to be responsible for the improved results.
The relative stability of NH 3 as a growth species has the disadvantage that H can be incorporated as an impurity into the crystal lattice, where it can interfere with activation of the N ions. Even if a N ion is located in a proper substitutional site, an adjacent interstitial H can prevent the N from performing its intended function as an acceptor.
It is thought that introducing the NH 3 with the cation species results in a weak association of the cation with the N, thus aiding in both the dissociation of NH 3 and the proper incorporation of N into the lattice. If the anion species were present, it would interfere with this association of the cation and the N. On the other hand, the presence of the anion alone on the growth surface tends to attract the cation and its associated N, allowing incorporation of the cation into the II sublattice, and the N into the VI sublattice.
In accordance with another preferred embodiment, the epi layer is grown in an FME sequence starting with the introduction of the cation or anion species alone into the growth chamber, to form cations or anions on the substrate to stabilize the growth surface, followed by the introduction of the anion species with the cation species, to form a layer of the semiconductor compound, followed by removal of the cation species from the growth chamber, to form a layer of anions on the growth surface, followed by removal of the anion species and co-introduction of the cation species and the NH 3 , to form a layer of cations and dopant. Except for the initial introduction of the cation or anion species to stabilize the surface, the sequence is repeated to build up an epi layer of the desired thickness.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be described in terms of a limited number of embodiments in connection with the accompanying drawing, in which:
FIG. 1 shows a typical pulse sequence for the FME growth of an epi layer in accordance with the method of the invention;
FIGS. 2 through 4 are photoluminescense (PL) spectra for epi layers of ZnSe doped with N grown by MOCVD under different conditions in order to illustrate the advantages of the inventive method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a schematic diagram illustrating a typical pulse sequence for the FME growth by MOCVD of an epi layer in accordance with the method of the invention, flow rate of the growth species in the growth chamber is represented on the y axis in arbitrary units for each of three growth species, while pulse time is represented on the x axis. Typical growth species for an N-doped ZnSe layer are dimethyl zinc (DMZn), dimethyl selenium (DMSe) and ammonia (NH 3 ) Other growth species which may be used are diethyl (DE), diisopropyl (DIP) Zn or Se, or H 2 Se. As is known, dissociation of DM and DE species must be photoassisted.
It will be readily appreciated that for given flow rates, the thickness of the various layers can be controlled by the pulse duration. The dopant concentration can also be controlled in this manner, up to the point at which the growth surface becomes saturated with dopant. The dopant concentration can also be controlled by changing the thickness of the ZnSe layer between the dopant pulses (for a constant dopant pulse duration). In FIG. 1, the doping pulse is indicated as Td. For typical growth conditions, i.e., growth on a GaAs substrate at a temperature of from about 325 to 450 degrees C., at flow rates of about 0.25 sccm to 2.00 ccm for the DMZn and DMSe and 25 sccm for the NH 3 , Td could range from 0.05 to 0.6 minutes, while saturation could begin to occur at about 0.2 minutes. The ZnSe growth pulse, indicated as Tg, could range from 0.05 to 0.6 minutes, while the so-called Se stabilization pulse, Tse, could range from 0.05 to 0.15 minute.
The actual growth temperature chosen is dictated by a compromise between growth time (longer at lower temperatures), dopant dissociation (lower at lower temperatures) and sticking coefficient (lower at higher temperatures). A preferred temperature based on these considerations is about 350 (±5) degrees C. The thickness of the individual sublayers can range from a fraction of a monolayer to a monolayer, usually a monolayer, for the initial cation or anion stabilizing layer, and from a few monolayers up to several hundred angstroms for the growth layer. Generally, for a single growth species, an equilibrum between adsorption and desorption limits its coverage to a maximum of one monolayer. The maximum thickness of the growth layers (e.g., ZnSe) is determined by the level of doping desired (e.g., several hundred Angstroms for 10 16 /cc but only about 50 Angstroms for 10 18 /cc). Making the growth layers too thick results in uneven distribution of the dopant in the final epi layer.
In order to illustrate the advantages of the invention, several epi layers of ZnSe on GaAs were produced by MOCVD, and PL spectra were obtained. A first layer was grown in accordance with the teachings of the prior art by introducing the DMZn, DMSe and NH 3 together throughout growth. Second and third layers were grown by FME. In the second layer, NH 3 was pulsed without DMZn, while in the third layer, NH 3 and DMZn were pulsed together.
In the second layer, the surface was stabilized with DMZn before introducing NH 3 . In the third layer the surface was stabilized with DMSe prior to introducing NH 3 and DMZn. Growth conditions for each of these three layers were as follows:
Growth temperature=375 C.;
DMZN, DMSe, flow rate 0.5 sccm;
NH 3 flow rate -25 sccm;
FME Layers
Growth pulse, 0.15 min.
Stabilization pulse, 0.15 min.
Doping pulse, 0.30 min.
The PL spectra for these three layers are shown in FIGS. 2-4, respectively, in which wavelength in angstroms is plotted on the x axis and luminescent intensity in arbitrary units is plotted on the y axis. In these spectra, the peaks labeled Aox indicate the presence of N acceptors, while the relative height of the A o x peaks with respect to the peak labeled Fx indicate the concentration of activated N acceptors. A comparison of FIGS. 2 and 4 shows that the method of the invention (FIG. 4) results in a higher incorporation of acceptors, and higher activation level, indicated by an Aox/Fx ratio higher by a factor of about 2.
Comparing FIGS. 3 and 4 shows that introducing the NH 3 with DMZn in accordance with the invention instead of alone (or with DMSe) is essential to enhance both the incorporation and activation of N acceptors.
The crystal quality of the layer of the invention is also improved over that of the prior art, as indicated by the greater widths of the peaks in the PL spectrum of FIG. 2.
Layers produced in accordance with the invention will benefit from the rapid thermal anneal described and claimed in the above-mentioned copending U.S. application Ser. No. 851,452, incorporated herein by reference. When subjected to such an anneal, samples have exhibited net acceptor concentrations Na--Nd in the range of about 5×10 15 to 3×10 16 , for doping levels of 3×10 17 cm -3 and 1×10 18 /cc, respectively, as measured by the CV technique described in said application.
The FME grown layer (third layer) shows a higher activation of acceptors at lower annealing temperatures, compared to the regular doped layer (first layer) for the same amount of Nitrogen incorporated in the crystal. For example, when annealed at 700 C. for 10 sec., the values of N a --N d are 1×10 15 and 2×10 16 /cc, for the first and third layers, respectively, for a common doping level of 1×10 18 /cc.
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Epitaxial layers of N-doped II-VI semiconductor compounds are grown on GaAs substrates by MOCVD using FME. Separating the growth and doping by alternating introduction of (1) the semiconductor cation and anion and (2) the cation and the dopant increases the level of doping, the level of activation, and the crystal quality.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/110,263, filed Jan. 30, 2015; U.S. Provisional Application No. 62/112,032, filed Feb. 4, 2015; and U.S. Provisional Application No. 62/113,092, filed Feb. 6, 2015, which are incorporated by reference herein.
TECHNICAL FIELD
[0002] This description relates generally to signal processing, and more particularly to a method for improving response time, robustness, and user comfort in continuous estimation of biophysiological rates.
BACKGROUND
[0003] Signal processing generally encompasses collecting, organizing, transforming and summarizing raw input data to produce meaningful or useful information, or output data. Signal processing is the enabling technology for the generation, transformation, and interpretation of information. Signal processing typically uses computational or heuristic representations and techniques to acquire, extract, represent, model or analyze data embedded in an analog or digital signals, including, for example, audio, image, video, controls, radio frequency, and other electrical signals.
[0004] In general, signal processing entails processes such as sampling sensor and instrument signals; analog-to-digital (A/D or ADC) and digital-to-analog (D/A or DAC) conversion of signals; filtering signals for the purpose of noise reduction, enhancement, reconstruction of the original signal or an approximation of the signal, and the like. Computational techniques and mathematical models employed include, for example, arithmetic operations, differential and integral calculus, differential equations, transform theory, time-frequency analysis of non-stationary signals, spectral analysis, probability and statistical analysis, vector analysis and linear algebra, parametric signal modeling, detection theory, estimation theory, optimization, and other numerical methods.
[0005] Digital signal processing (DSP) typically is carried out by general purpose computers or specialized controllers. DSP makes use of discrete mathematics, including the representation of discrete time series, discrete frequency, and other discrete domain signals as a sequence of numbers or symbols and the processing of these signals. Discrete-time signal processing generally applies to sampled signals, such as signals generated by electrical, optical, or electromechanical sensors.
[0006] Nonlinear signal processing involves the analysis and processing of signals produced from nonlinear systems in the time, frequency, or spatio-temporal domains. Nonlinear systems produce relatively complex signal characteristics that in some cases cannot be modeled or analyzed using linear methods.
[0007] The Hilbert transform is a linear operator that shifts the phase of frequency components of a function or signal in the same domain as the original function or signal. Complex, sequential, discrete pairs, [u(t), û(t)] or [u(t), Hu(t)], in which the real part is represented by the original function or signal and the imaginary part is represented by the discrete Hilbert transform of the function or signal compose an analytical signal. The Hilbert transformed series has the same amplitude and frequency content as the original function or signal, and includes phase information that correlates to the phase of the original function or signal.
[0008] In general, the Hilbert transform is useful in calculating instantaneous attributes of a time series, in particular, amplitude and frequency. The amplitude of the analytical signal is equal to the instantaneous amplitude of the original signal, and the time rate of change of the phase angle of the analytical signal is equal to the instantaneous frequency of the original signal.
[0009] Cardiovascular periodicity generally refers to the nearly regular, recurrent blood pressure and volume pulses induced by the heart. The time length of each period between consecutive individual heart beats is commonly referred to as the interbeat interval (IBI, or RR interval). The heart rate is the inverse of the cardiovascular periodicity.
[0010] During normal heart functioning, there is some variation in the continuous time series of IBI values. This natural variation is known as heart rate variability (HRV). Relatively noisy or low-amplitude sensor signals can add measurement error that further detracts from the nearly periodic nature of the observed heart beat signal. Thus, the observed heart beat sensor signal typically represents a quasiperiodic function. That is, the signal is similar to a periodic function, but displays irregular periodicity and does not meet the strict definition of a periodic function that recurs at regular intervals. Quasiperiodic behavior includes a pattern of recurrence with a component of unpredictability that does not lend itself to precise measurement.
[0011] The time intervals between consecutive heart beats are customarily measured in an electrocardiogram (ECG or EKG) from the initiation of each of two consecutive QRS complexes, corresponding to the contraction of the heart ventricles, each of which typically includes three component waveforms (the Q-wave, R-wave and S-wave). However, the initiation of the QRS complex can be difficult to locate in relatively noisy or low-amplitude sensor signals, which can lead to measurement error. Thus, IBI sometimes is measured between R-wave peaks in consecutive heart beats to reduce measurement error.
[0012] IBI can also be determined from a peripheral pulse measurement, such as a digital volume pulse measurement, such as a photoplethysmogram (PPG), an optically obtained plethysmogram, or volumetric measurement of an organ. The pulse oximeter, a known type of PPG sensor, illuminates the skin with one or more colors of light and measures changes in light absorption at each wavelength. The PPG sensor illuminates the skin, for example, using an optical emitter, such as a light-emitting diode (LED), and measures either the amount of light transmitted through a relatively thin body segment, such as a finger or earlobe, or the amount of light reflected from the skin, for example, using a photodetector, such as a photodiode. PPG sensors have been used to monitor respiration and heart rates, blood oxygen saturation, hypovolemia, and other circulatory conditions.
[0013] Conventional PPGs typically monitor the perfusion of blood to the dermis and subcutaneous tissue of the skin, which can be used to detect, for example, the change in volume corresponding to the pressure pulses of consecutive cardiac cycles of the heart. If the PPG is attached without compressing the skin, a secondary pressure peak can also be seen from the venous plexus. A microcontroller typically processes and calculates the primary peaks in the waveform signal to count heart beats per minute (bpm).
[0014] Offsets, or DC shifts, can occur in biophysiological sensor signals as a result of inconsistencies in the interface between a subject and a sensor, such as an ECG electrode or a PPG optical sensor. The subject may include, but not limited to, a person, an animal, and a living organism. As a result, sensor designs typically must ensure a reliable mechanical interface between the subject and the sensor. In the case of some wearable devices with biophysiological sensors, including, for example, wrist-based wearables, there is a direct relationship between comfort (corresponding to a relatively loose attachment) and a reliable mechanical interface (corresponding to a relatively tight attachment).
SUMMARY
[0015] According to one embodiment, an apparatus for estimating biophysiological rates using a Hilbert transform includes a memory that stores machine instructions and a processor coupled to the memory that executes the machine instructions to receive a quasiperiodic data stream from a biophysiological sensor, remove at least a portion of an offset from the quasiperiodic data stream to provide a smoothed data stream by filtering the quasiperiodic data stream through a bandpass filter and phase compensating the filtered quasiperiodic data stream, transform the smoothed data stream into an analytic data stream using a Hilbert transform approximation, calculate a time derivative associated with a phase angle of the analytic data stream, and provide an output data stream derived from a frequency, wherein the frequency is the time derivative of the quasiperiodic data stream.
[0016] According to another embodiment, a method for estimating biophysiological rates using the Hilbert transform includes receiving a quasiperiodic data stream from a biophysiological sensor, and removing at least a portion of an offset from the quasiperiodic data stream to provide a smoothed data stream by filtering the quasiperiodic data stream through a bandpass filter and phase compensating the filtered quasiperiodic data stream. The method also includes transforming the smoothed data stream into an analytic data stream using a Hilbert transform approximation, and calculating the time derivative associated with the phase angle of the analytic data stream, where the time derivative is a frequency of the quasiperiodic data stream. The method further includes providing an output data stream derived from the frequency.
[0017] According to yet another embodiment, a computer program product for estimating biophysiological rates using a Hilbert transform includes a non-transitory, computer-readable storage medium encoded with instructions adapted to be executed by a processor to implement receiving a quasiperiodic data stream from a biophysiological sensor, and removing at least a portion of an offset from the quasiperiodic data stream to provide a smoothed data stream by filtering the quasiperiodic data stream through a bandpass filter and phase compensating the filtered quasiperiodic data stream. The instructions are further adapted to implement transforming the smoothed data stream into an analytic data stream using a Hilbert transform approximation, calculating a time derivative associated with a phase angle of the analytic data stream, where the time derivative is a frequency of the quasiperiodic data stream, and providing an output data stream derived from the frequency.
[0018] The details of one or more embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present disclosure will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a block diagram depicting an exemplary rate estimating device using the Hilbert transform in accordance with an embodiment.
[0020] FIG. 2 illustrates a flowchart representing an exemplary method of estimating a biophysiological rate using the Hilbert transform in accordance with an embodiment.
[0021] FIG. 3 illustrates a flowchart representing an exemplary method of sensor signal filtering and frequency estimation in accordance with an embodiment.
[0022] FIG. 4 illustrates a flowchart representing an exemplary method of sensor signal envelope excursion detection in accordance with an embodiment.
[0023] FIG. 5 illustrates a schematic view depicting an exemplary general computing system that may implement a rate estimating device in accordance with an embodiment.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates a block diagram depicting an exemplary rate estimating device using the Hilbert transform in accordance with an embodiment. An exemplary rate estimating device 10 employs a Hilbert transform process to continuously estimate biophysiological rates, for example, a heart rate. The rate estimating device 10 includes a sensor signal receiver 12 , a signal offset remover 14 , a rate estimator 16 , an envelope excursion fault detector 18 , and a motion fault detector 20 . The rate estimating device 10 processes a stream of biophysiological sensor data over time and outputs a stream of biophysiological feature data, for example, an interbeat interval or instantaneous heart rate.
[0025] The sensor signal receiver 12 receives biophysiological sensor data as input, for example, a photoplethysmogram (PPG) sensor signal, and converts the data to an appropriate format for signal processing. In various embodiments, biophysiological sensor data that may be analyzed using the method described in this disclosure include, for example, optical sensor data (e.g., (PPG)), electrical potential sensor data (e.g., an electrocardiogram (ECG or EKG), and electrical impedance sensor data (e.g., Bio Z® impedance cardiography (ICG)).
[0026] The signal offset remover 14 removes a direct-current (DC) offset from the signal, such that the signal is centered at approximately zero volts. For example, the signal offset remover 14 implements a high-pass filter to remove the signal DC offset. The signal offset remover 14 provides initialization.
[0027] The rate estimator 16 implements additional bandpass filtering and applies Hilbert transform approximations to estimate the periodic rate of the signal. The Hilbert-transform based approach to rate estimation of a quasiperiodic signal constructs an analytic signal which has a real part as the original signal and an imaginary part that is phase-shifted from the original by 90 degrees. The phase shift may be accomplished either explicitly in the Fourier domain, or using a time-domain filter designed for the purpose. The phase of the analytic signal is differentiated to obtain an instantaneous frequency.
[0028] In order to facilitate relatively accurate frequency estimation using the Hilbert transfer that is relatively tolerant of DC-level shifts, the rate estimating device 10 simultaneously combines three basic approaches to mitigate these effects. The process implements phase-compensated infinite impulse response (IIR) digital filtering, motion masking to handle motion artifacts and activity corruption, and envelope masking based on Hilbert analytic amplitude to increase robustness with respect to rate changes.
[0029] The excursion fault detector 18 applies Hilbert envelope-based masking based on the Hilbert analytic amplitude to increase robustness with respect to rate changes. The motion fault detector 20 applies motion masking to handle motion artifacts and activity corruption.
[0030] The Hilbert-transform based approach has excellent signal recovery characteristics for stable, smooth signals, even when the instantaneous frequency changes over a small number of signal periods. The approach is also fairly robust with respect to uniform Gaussian noise, but is less tolerant of non-Gaussian noise. The approach is particularly affected when the fundamental frequency is corrupted by low frequency noise. Heuristically, the analytical signal is presumed to have a zero-mean, and therefore the low frequency content generally is ascribed to either changes in amplitude or changes in frequency/phase. Shifts in the mean amplitude, or DC level, may be especially problematic, since these may cause large deviations in the instantaneous frequency.
[0031] Sensor signal processing inference approaches that improve the robustness to DC-level shifts have a direct impact on the required mechanical interface between the body and the sensor. With regard to some wearable devices, this requirement translates into tightness of the attachment, which translates into comfort for many mechanical designs. As a result, increased system tolerance with regard to DC-level shifts may enable looser, more comfortable wearable device designs.
[0032] FIG. 2 illustrates a flowchart representing an exemplary method of estimating a biophysiological rate using the Hilbert transform in accordance with an embodiment. A process of continuous estimation of biophysiological rates (e.g., a heart rate) based on the Hilbert transform may be performed, for example, by a biophysiological rate estimating device 10 . The process performs rate estimation based on fluctuations in sampled raw data. The process begins by receiving biophysiological sensor data 30 as input, for example, an optical PPG sensor signal.
[0033] At 32 , the digital data type of the sensor data 30 is converted, for example, to a double-precision floating-point number for further processing. At 34 , when the sensor data includes an essentially direct-current (DC) component, a high-pass filter (HPF) removes the DC offset to produce an output signal that is centered approximately at zero volts. Additional bandpass filtering may be performed to accomplish signal smoothing and phase compensation, and Hilbert transform-based approximations may be applied to determine the frequency of the output signal of 34 . At 36 , the periodic rate associated with the output signal of 34 is estimated.
[0034] At 38 , an envelope excursion detection, for example, based on Hilbert transform, is performed to detect an envelope excursion fault and set an envelope excursion fault detector flag. At 40 , if an envelope excursion fault detector flag is received, a fault flag is set during an envelope excursion fault hysteresis time period 42 (e.g., 1.5 s).
[0035] At 46 , if a motion signal 44 is received from a motion sensor, such as an onboard accelerometer in a wearable device, a fault flag is set and output during a motion fault hysteresis time period 48 . For example, a flag is triggered by a fixed threshold with respect to the accelerometer signal. The input motion estimation method masks the heart rate signal during motions that may lead to undesirable DC shifts. Motion masking may reduce or eliminate the signal effects generated by subject movements, for example, that of a wearable sensor.
[0036] At 50 , if a fault flag from either 40 or 46 is detected by the logical operator (e.g., “OR”), the switch at 52 produces an output based on the masked rate output (e.g., zero) 54 . Otherwise, the estimated rate output of 36 is converted to an appropriate data type format at 56 , and outputted at 52 . The output rate of 52 is sent at 58 .
[0037] FIG. 3 illustrates a flowchart representing an exemplary method of sensor signal filtering and frequency estimation in accordance with an embodiment. FIG. 3 presents additional detail regarding the DC offset removal bandpass filtering and Hilbert-based frequency estimation performed at 36 of FIG. 2 , according to one embodiment. The process begins by receiving a preprocessed sensor signal 60 . At 62 , a bandpass filter filters the preprocessed sensor signal 60 using a design for high-pass rejection to mask low-frequency noise, for example, a biquadratic filter having low and high filter cutoff frequencies of 30 and 150 beats per minute (bpm), respectively.
[0038] At 64 , an all-pass phase compensation bandpass filter, for example, a phase-compensated infinite impulse response (IIR) biquadratic filter filters an output signal of 62 . This approach permits the use of a lower-order filter than would be required, for example, using a linear-phase finite impulse response (FIR) filter. The lower-order filter may avoid lag issues and reduce the required microcontroller memory with respect to some FIR designs, which is particularly important in embedded platforms. Further, phase compensation may reduce or minimize corruption to the analytic signal used to estimate the output rate.
[0039] At 66 , an integer delay (e.g., Z −5 ) is applied to the output signal of 64 . At 68 , a Hilbert transform approximation is performed in parallel on the output signal of 64 , for example, using the Filter Design and Analysis Tool (FDATool) function in MATLAB® high-level language and interactive environment by MathWorks®. The output signals of 66 and 68 make up the analytic signal components. At 70 , the output signal of 66 is used as a real component for a complex number and the output signal of 68 is used as an imaginary component for the complex number. The complex number makes up an analytic signal. At 72 , the analytic signal is converted to a data stream with magnitude-angle format. At 74 , the magnitude, or absolute value, of the data stream is output as a signal envelope (e.g., PPG Env).
[0040] At 76 , the phase angles of the data stream including the signal envelope are corrected to smooth the data stream and provide a corrected envelope signal, for example, using an unwrap function in MATLAB®. At 78 , the discrete derivative of the corrected envelope signal with respect to time is calculated. At 80 , upper and lower limits are imposed to limit the output signal of 78 to a predetermined range. For example, a saturation function in MATLAB® may be used to limit a signal range of the output signal of 78 . At 82 , a low-pass filter filters the output signal of 80 to smooth and provide an estimated rate 84 .
[0041] FIG. 4 illustrates a flowchart representing an exemplary method of sensor signal envelope excursion detection in accordance with an embodiment. FIG. 4 presents additional detail regarding the sensor signal envelope excursion detection performed at 38 of FIG. 2 , according to one embodiment. The process begins at 90 by receiving the signal envelope (e.g., PPG Env) from block 74 of FIGS. 3 . At 92 and 94 , low-pass filtering is performed in parallel on the signal envelope to produce relatively fast-varying and relatively slow-varying smoothed versions of the signal envelope. For example, a biquadratic low-pass filter having a cutoff frequency of approximately 0.5 Hz is applied on the signal envelope at 92 , and a biquadratic low-pass filter having a cutoff frequency of approximately 0.067 Hz is applied in parallel on the signal envelope at 94 .
[0042] At 98 , a divide-by-zero offset 96 is added to the slow-varying version of the envelope signal from 92 . At 100 , the fast-varying version of the envelope signal from 94 is divided by the output signal of 98 . At 102 , the natural log of output signal of 100 is evaluated. At 104 , if the output signal of 102 is compared to and greater than a predetermined constant (e.g., 0.8), the logical outcome of the comparison is “true.” At 106 , if the output signal of 102 is compared to and less than a predetermined constant (e.g., −0.8), the logical outcome of the comparison is “true.”
[0043] At 108 , the slow-varying version of the envelope signal from 92 is divided by the envelope signal from 90 . At 110 , the natural log of the output signal of 108 is evaluated. At 112 , the fast-varying version of the envelope signal from 94 is divided by the envelope signal from 90 . At 114 , the natural log of the output signal of 112 is evaluated. At 116 , the output signal of 110 is divided by the output signal of 112 . At 118 , an absolute value for the output signal of 116 is determined.
[0044] At 120 , if the absolute value is compared to and less than a predetermined constant (e.g., 2), the logical outcome of the comparison is “true,”. At 124 , a default output (e.g., zero) 122 is selected if the logical outcome of 120 is “true”, otherwise, the output signal of 116 is selected. At 126 , if the output value of 124 is zero, the result is also zero. However, at 126 , if the output value of 124 is greater than or less than zero, the result is one (1) or negative one (−1), respectively. At 128 , an absolute value of the result of 126 is taken. At 130 , if a logical “true,” or “1,” is detected at the logical operator (e.g., “OR”), then an envelope excursion fault detector flag is output at 132 .
[0045] The Hilbert transform envelope-based masking is used to detect relatively high variability and remove associated data points from the output rate estimate. Since the frequency estimation approach is known to work well for relatively consistent quasiperiodic signals, excessive variability in the analytic amplitude is a reliable indicator of errors in the frequency estimation.
[0046] Using the method of FIG. 4 , deviations are detected between the analytic signal amplitude and each relatively slow-varying and fast-varying smoothed versions of the signal. Significant deviations indicate non-stationary behavior that is likely to lead to corrupted rate estimates. The deviations are compared to preset limits and a flag is set if the deviations are above a threshold.
[0047] The deviation detection method of FIG. 4 essentially detects deviations in the log-ratio of the signal. The Hilbert envelope is typically consistent, but is sensitive to transient irregularity in the sensor signal. These conditions, essentially deviations in the signal log ratio, function as a “burstiness” detector to the Hilbert envelope, detecting irregularities between the Hilbert envelope and relatively slow and fast smoothed versions of the signal.
[0048] FIG. 5 illustrates a schematic view depicting an exemplary general computing system that may implement a rate estimating device in accordance with an embodiment. An exemplary computing device 140 that may implement a rate estimating device includes a processor 142 , a memory 144 , an input/output device (I/O) 146 storage 148 and a network interface 150 . The various components of the computing device 140 are coupled by a local data link 152 , which in various embodiments incorporates, for example, an address bus, a data bus, a serial bus, a parallel bus, or any combination of these.
[0049] The computing device 140 may be used, for example, to implement the present method of estimating biophysiological rates. Programming code, such as source code, object code or executable code, stored on a computer-readable medium, such as the storage 148 or a peripheral storage component coupled to the computing device 140 , may be loaded into the memory 144 and executed by the processor 142 in order to perform the present method of estimating biophysiological rates.
[0050] Aspects of this disclosure are described herein with reference to flowchart illustrations or block diagrams, in which each block or any combination of blocks may be implemented by computer program instructions. The instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to effectuate a machine or article of manufacture, and when executed by the processor the instructions create means for implementing the functions, acts or events specified in each block or combination of blocks in the diagrams.
[0051] In this regard, each block in the flowchart or block diagrams may correspond to a module, segment, or portion of code that including one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functionality associated with any block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or blocks may sometimes be executed in reverse order.
[0052] A person of ordinary skill in the art will appreciate that aspects of this disclosure may be embodied as a device, system, method or computer program product. Accordingly, aspects of this disclosure, generally referred to herein as circuits, modules, components or systems, may be embodied in hardware, in software (including firmware, resident software, micro-code, etc.), or in any combination of software and hardware, including computer program products embodied in a computer-readable medium having computer-readable program code embodied thereon.
[0053] It will be understood that various modifications may be made. For example, useful results still could be achieved if steps of the disclosed techniques were performed in a different order, and/or if components in the disclosed systems were combined in a different manner and/or replaced or supplemented by other components. Accordingly, other implementations are within the scope of the following claims.
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A computer-implemented method for estimating biophysiological rates using the Hilbert transform includes receiving a quasiperiodic data stream from a biophysiological sensor, and removing at least a portion of an offset from the quasiperiodic data stream to provide a smoothed data stream by filtering the quasiperiodic data stream through a bandpass filter and phase compensating the filtered quasiperiodic data stream. The method also includes transforming the smoothed data stream into an analytic data stream using a Hilbert transform approximation and calculating the time derivative of the phase angle of the analytic data stream, where the time derivative is a frequency of the quasiperiodic data stream. The method further includes providing an output data stream derived from the frequency.
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BACKGROUND OF THE INVENTION
The present invention relates to musical keyboards utilized in musical instruments such as electronic organs and the like.
A typical example of the conventional keyboard employed in the electronic organ is illustrated in FIG. 1, in which a reference numeral 1 indicates a natural or white key, the rear end 3 of which is connected to a supporting portion or fulcrum 5 of a key bed or key supporting frame 7 for pivotal contact with that fulcrum. The key 1 is urged to swing upwardly by a coil spring 9 which is held vertically between key bed 7 and a spring receiving portion 4 of key 1, and it is normally held in a rest or non-operative position by bringing a substantially L-shaped stopper 11 extending downwardly from key 1 into abutment with a stopper receiving member 13 of felt provided on the lower surface of key bed 7. With this arrangement, when key 1 is depressed, a key switch 15 which is mounted on a printed circuit board 17 is closed by making an actuator 19 extending downwardly from key 1 actuate it, whereby a musical note corresponding to the depressed key 1 is emitted by well known electronical means. The key bed 7 has further a guide member 21 struck out therefrom for preventing key 1 from moving laterally.
With the above prior art keyboard structure, the mounting of keys 1 on key bed 7 necessitates laborious fitting of coil spring 9 into a spring receiving portion 4 of each key 1. Furthermore, it is difficult to reduce the thickness of the keyboard since coil springs 9 are vertically disposed on key bed 7. The keyboard further needs an additional stopper 23 for each key 1 to prevent the coming off of that key 1 from key bed 7. This is because when key 1 is pulled while the rear end 3 thereof is depressed, coil springs 9 are compressed and fallen forward, so that the pivoted portion of key 1 can disengage from the fulcrum 5 of key bed 7.
Keyboards similar to the above described are disclosed for example in Japanese Utility Model Publication Sho54-29780 and Japanese Utility Model Preliminary Publication Sho52-141,928.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a keyboard in which keys and key-biasing springs are easily set up in the key bed, thereby enabling reduction in manufacturing cost and labor.
It is another object of the invention to provide a keyboard of which thickness is considerably reduced.
It is a further object of the invention to provide a keyboard in which key touch is improved.
With these and other objects in view the present invention will provide a musical keyboard comprising a key bed having fulcrums formed therein, a row of keys each having a supported portion located at the rear end thereof for pivotal contact with the corresponding fulcrum for vertical swinging between a rest position and an operative position, and resilient means for urging the keys upwards to the rest position. The resilient means includes a leaf spring positioned below the keys and secured to the key bed to extend substantially horizontally towards the fulcrums, the free end of the leaf spring engaging the lower surface of each key to urge that key upwards.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims which particularly point out and distinctly define the subject matter which is regarded as the invention, it is believed that the invention will be more clearly understood when considering the following detailed description and the accompanying drawings in which:
FIG. 1 is a vertical section of one example of the prior musical keyboard;
FIG. 2 is a vertical section of a keyboard constructed according to the present invention;
FIG. 3 is a fragmentary plan view of a comb-shaped leaf spring used in the key board in FIG. 2;
FIG. 4 is a bottom view of a key switch holder shown is FIG. 2;
FIG. 5 is an explanatory view illustrating the operation of the key in FIG. 2;
FIG. 6 is a fragmentary vertical section of a slightly modified key of FIG. 2; and
FIG. 7 is a plan view showing another embodiment of the leaf spring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 2 and 3, a reference numeral 25 designates a generally rectangular key bed for use in an electronic organ, the key bed 25 being fastened at its peripheral lugs 27 to a casing (not shown) of the electronic organ by means of machine screws and the like. The key bed 25 has many pairs of rectangular openings 29 and 31 formed in position therein. The rearside periphery 33 of the opening 31 forms a fulcrum on which a white key 35 or black key 37 is supported for vertical movement as will be described later. A comb-shaped leaf spring 39 is sandwiched between key bed 25 and a spring holding member 41 of an elongated plate and fastened to the lower surface of key bed 25 near opening 31 in a cantilever fashion by means of screws 43 so that the comb teeth thereof extend substantially horizontally toward the rear end of key bed 25. The leaf spring 39 may be formed from any suitable conventional spring material. In the embodiment shown in FIG. 3, the leaf spring 39 consists of large comb teeth 45 for white keys 35 and small comb teeth 47 for black keys 37, both teeth 45 and 47 being of an isosceles triangular shape and being equal in number to white keys 35 and black keys 37, respectively.
As shown in FIGS. 2 and 4, the spring holding member 41 is integrally formed with a vertical wall 51 of a key switch holder 50 and extends horizontally therefrom. From the other side of the vertical wall 51 there extend vertically key guides 53 in an equi-spaced relationship, and as a result a key guide slot 55 is formed between the adjacent two key guides 53. The lower surface of each key guide 53 has a recess 54 formed therein. Onto the lower end of each guide 53 and the lower edge of vertical wall 51 there is fastened a printed circuit board 57 on which a key switch assembly 59 is mounted to fit in the recess 54 of guide 53. The respective key switches are arranged to be positioned at the guide slots 55 so as to be in the movement paths of key switch actuators 77 described below.
On the upper surface of key bed 25 there are arranged a certain number of white keys 35 and black keys 37 of thermoplastic material in a juxtaposed relationship. The white key 35 is of a generally inverted U-shaped cross-section and comprises a rectangular body 61, a pair of side walls 63 (only one of which is shown) extending downwardly from the opposite edges of that body 61, and a supported portion 65 extending vertically downwardly from the rear end of body 61. The supported portion 65 has a transverse groove 67 formed on the rearside thereof, the groove 67 being adapted for pivotal contact with fulcrum 33 for vertical swinging of key 35. On the lower side of supported portion 65, there is provided a shoulder 69 having a horizontal surface which serves as a spring receiving portion, the shoulder 69 terminating in a key lock 71 which extends vertically downward therefrom. At the mid-portion of each side wall 63 of the white key 35 there is provided a substantially L-shaped stopper 73 extending downwardly therefrom. One of the stoppers 73 on both side walls 63 is formed with a key switch actuator 77 which is thus located in the guide slots 55 (FIG. 4) to oppose a corresponding key switch. The black key 37 has a substantially similar construction to the white key 35 and hence explanation thereof is omitted.
In mounting leaf spring 39 and white key 35 or black key 37 on key bed 25, the base portion of the leaf spring 39 is interposed between key bed 25 held upside down and spring holding member 41 in a sandwich manner and then fastened by means of screw bolts 43, then the key bed 25 is placed as shown in FIG. 2. Next, a pair of stoppers 73 and the supported portion 65 of white key 35 or black key 37 are inserted into the corresponding openings 29 and 31, respectively and pushed backwards or in a direction indicated by the arrow shown in FIG. 2 to bring transverse groove 67 into engagement with pivot 33 for pivotal contact therewith, in which event the tip of each comb tooth 45 or 47 comes into abutment with key lock 71 after urged downwardly by the lower end of key lock 71. In this stage, the comb spring urges the shoulder 69 upwardly so that the key is biased upwardly, but is held in a rest or non-operative position by bringing legs 75 of stopper 73 into abutment against a stopper receiving member 81 of felt which is attached to the lower surface of key bed 25 in the vicinity of opening 29, the legs 75 being inserted into respective key guide slots 55 defined by the adjacent key guides 53.
In this embodiment, comb-shaped leaf spring 39 is employed in place of the coil spring as in the prior key board. This largely facilitates the attaching of the spring to key bed 25 and also the setting up of keys 35 and 37 to key bed 25 and can reduce the thickness of the whole instrument since leaf spring 39 can be disposed substantially horizontally. Furthermore, the free end of leaf spring 39 abuts against the key lock 71 of each key 35 or 37 and thereby keys are prevented from coming out of the key bed 25 when pulled forward.
In operation, white key 35 or black key 37 is depressed and swung downwardly against the spring 39 to a depressed or operative position where the lower edges of the side walls 63 of each key come into contact with a shock absorber 83 and 85 of felt which are applied on the upper surface of key bed 25 through adhesive, and the actuator 77 contacts simultaneously the corresponding key switch 59 to close a circuit and sound a tone electronically by conventional means (not shown). Then, the key 35 or 37 is released and allowed to return to its original position or non-operative position in FIG. 2 by the force of leaf spring 39.
Now, key touch of the present invention will be described with reference to FIG. 5. When the white key or black key is depressed from the non-operative position indicated by the solid line to an operative position indicated by a phantom line in FIG. 5, the deflection amount and angle of the tooth spring 45 or 47 are increased and the point of contact of shoulder 69 with that tooth spring moves toward the free end of the latter, with the result that the perpendicular line from fulcrum 33 to the line of action of force Q exerted by comb tooth 45 or 47 on shoulder 69 reduces from l 1 to l 2 . Therefore the force Q 2 which is exerted from the comb tooth on key 35 or 37 when that key is in the operative position does not become too large as compared to the force Q 1 when it is in the non-operative position. Consequently, the rotation moment applied to that key by leaf spring 39 will not increase largely and thus the key touch feeling does not become heavier as the key is depressed, which is desirable in a keyboard musical instrument.
In the above embodiment, the comb teeth 45 and 47 of leaf spring 39 abut at free ends against their respective key locks 71 of keys 35 and 37 and contact the shoulders near the free ends thereof to urge the keys 35 and 37 upwardly. However, as shown in FIG. 6, shoulder 89 may be formed to be inclined downwardly so that shoulder 89 and key lock 71 meet at corner 91 with a obtuse angle, thereby bringing the free end of tooth comb 45 or 47 into abutment with corner 91 to urge the key upwards. With this construction, there will be no possibility as in the previous embodiment that when a key is stroungly pulled forward in the state that it is in a depressed position as shown by the phantom line in FIG. 5, the free end of the corresponding comb tooth 45 or 47 is stucked into key lock 71 of that key and thus the key is prevented from returning to its original position when released.
The leaf spring employed in the present invention is not limited to comb-shaped leaf spring 39, but may be a single leaf spring 87 of substantially an isosceles triangle as shown in FIG. 7 in which case leaf springs 87 equal in number to the white and black keys are used for a keyboard, and the base portion of each spring is fastened to key bed 25 is a cantilever fashion.
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A musical keyboard includes a key bed having fulcrums formed therein, a row of keys each having a supported portion located at the rear end thereof for pivotal contact with the corresponding fulcrum for vertical swinging between a rest position and an operative position, and a resilient device for urging the keys upwards to said rest position. The resilient device has a leaf spring positioned below the keys and secured to the key bed to extend substantially horizontally towards the fulcrums, the free end of said leaf spring engaging the lower surface of each key to urge the key upwards.
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BACKGROUND
1. Technical Field
The present disclosure relates to a method for manufacturing light emitting chips, and more particularly, to a method for manufacturing light emitting chips having high light emitting efficiency.
2. Description of Related Art
As new type light source, LEDs are widely used in various applications. An LED often includes an LED chip to emit light. A conventional LED chip includes a substrate, and an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer sequentially grown on the substrate. The substrate is generally made of sapphire (Al 2 O 3 ) for providing growing environment to the layers. However, such sapphire substrate has a low heat conductive capability, causing that heat generated by the layers cannot be timely dissipated. Therefore, a new type substrate made of Si is developed. Such Si substrate has a thermal conductivity larger than that of the sapphire substrate so that the heat generated by the layers can be effectively removed.
Nevertheless, such Si substrate also has a problem that it absorbs the light emitted from the light-emitting layer due to the material characteristic thereof. Thus, the light extracting efficiency of the LED chip is limited.
What is needed, therefore, is a method for manufacturing light emitting chips which can overcome the limitations described above.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 shows a first process of a method for manufacturing light emitting chips in accordance with an embodiment of the present disclosure.
FIG. 2 shows a second process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 3 shows a third process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 4 shows a fourth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 5 shows a fifth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 6 shows a sixth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 7 shows a seventh process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 8 shows an eighth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 9 shows a ninth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 10 shows a tenth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 11 shows an eleven process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 12 shows a twelve process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 13 shows a thirteenth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 14 shows a fourteenth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 15 shows a fifteenth process of the method of manufacturing light emitting chips in accordance with the embodiment of the present disclosure.
FIG. 16 shows light emitting chips which have been manufactured by the method of FIGS. 1-15 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
A method for manufacturing light emitting chips in accordance with an embodiment of the present disclosure is disclosed. The method mainly includes multiple steps as described below.
As shown in FIG. 1 , a substrate 10 is provided. The substrate 10 is preferably made of Si. The substrate 10 has a flat top face for facilitating formation of semiconductor and other layers on the substrate 10 .
The substrate 10 is provided with a photoresist layer 20 on the top face thereof as shown in FIG. 2 . The photoresist layer 20 may be made of positive photoresist material or negative photoresist material, depending on the actual requirements.
The photoresist layer 20 is patterned to form a plurality of individual islands as shown in FIG. 3 . The islands of the photoresist layer 20 are spaced from each other by a plurality of gaps 22 between the islands. A plurality of areas of the top face of the substrate 10 are exposed to the gaps 22 . The method for patterning the photoresist layer 20 may be micro-lithography or other suitable technologies.
As shown in FIG. 4 , the substrate 10 is then heated in an environment containing a large amount of oxygen or nitrogen so that the exposed areas of the top face of the substrate 10 are reacted to form SiO 2 or Si 3 N 4 . Such SiO 2 or Si 3 N 4 acts as a blocking layer 12 which can prevent semiconductor structures from being grown therefrom. A temperature to heat the substrate 10 is preferably selected between 120 and 150 degrees centigrade. However, if high temperature-resistant material is employed to make the photoresist layer 20 , the temperature to heat the substrate 10 can raise to a range between 200 and 250 degrees centigrade. The photoresist layer 20 does not react with the oxygen or nitrogen and remains to cover the remaining areas of the top face of the substrate 10 .
The photoresist layer 20 is removed to expose the remaining areas of the top face of the substrate 10 as shown in FIG. 5 . The exposed remaining areas alternate with the reacted areas (i.e., the blocking layer 12 ) of the top face of the substrate 10 . The photoresist layer 20 may be removed by development or other suitable methods.
As shown in FIG. 6 , an epitaxy structure 30 is formed on the substrate 10 . The epitaxy structure 30 includes a first semiconductor layer 32 , a light-emitting layer 34 and a second semiconductor layer 36 grown on the exposed areas of the top face of the substrate 10 sequentially. In this embodiment, the first semiconductor layer 32 is an N-type GaN layer, the second semiconductor layer 36 is a P-type GaN layer, and the light-emitting layer 34 is a muti-quantum wells GaN layer. Alternatively, the first semiconductor layer 32 , the second semiconductor layer 36 and the light-emitting layer 34 can also be made of other suitable materials. Since the blocking layer 12 presented between the exposed areas of the top face of the substrate 10 prevents the epitaxy structure 30 from being grown therefrom, a plurality of channels 300 are defined just above the blocking layer 12 to divide the epitaxy structure 30 into a plurality of discrete blocks. However, in order to prevent the blocks of the epitaxy structure 30 from being grown laterally too much to connect with each other, a width of each channel 300 should be ensured twice more than a thickness of the epitaxy structure 30 .
An insulation material 40 is further filled into the channels 300 to have a top face thereof coplanar with that of the epitaxy structure 30 as shown in FIG. 7 . The insulation material 40 may be made of a material similar to that of the photoresist layer 20 or the blocking layer 12 . Preferably, a photoresist material is selected in this embodiment since the photoresist material has a good performance of filling.
A reflective layer 50 is further formed on the top faces of the epitaxy structure 30 and the insulation material 40 as shown in FIG. 8 . The reflective layer 50 is continuous to cover all the top faces of the epitaxy structure 30 and the insulation material 40 . The reflective layer 50 may be made of aluminum, silver or gold and formed via an E-gun or a PECVD (Plasma Enhanced Chemical Vapor Deposition) technology. The reflective layer 50 can reflect light emitted from the light-emitting layer 34 towards an outside environment, thereby increasing light-extracting efficiency of the light emitting chips.
As shown in FIG. 9 , a transition layer 60 is further formed on a top face of the reflective layer 50 via the E-gun or PECVD technology. The transition layer 60 may be made of silver, aluminum, gold or chrome. The transition layer 60 is used for joining another layer on the reflective layer 50 .
A base 70 is further formed on the transition layer 60 by electroplating as shown in FIG. 10 . The base 70 may be made of silver, aluminum, gold or cooper. The base 70 has a thickness far larger than that of the reflective layer 50 and that of the transition layer 60 . The base 70 functions to support the epitaxy structure 30 and absorb heat generated from the epitaxy structure 30 . The base 70 also acts as a conductor for introducing current into the epitaxy structure 30 .
As shown in FIG. 11 , a protective layer 80 is further provided to fully cover a top face of the base 70 , lateral faces of the base 70 , the transition layer 60 , the reflective layer 50 and the epitaxy structure 30 . The protective layer 80 also partially covers lateral sides of the substrate 10 . A bottom face of the substrate 10 is not covered by the protective layer 80 and is exposed to an external environment. The protective layer 80 may be made of corrosion-resistant materials such as wax.
As shown in FIG. 12 , the epitaxy structure 30 in combination with the other layers are inverted to render the bottom face of the substrate 10 facing upwardly, and the substrate 10 is wholly etched away to expose the bottom face of the first semiconductor layer 32 and the blocking layer 12 . The epitaxy structure 30 , the reflective layer 50 , the transition layer 60 and the base 70 are protected by the protective layer 80 from the etching.
As shown in FIG. 13 , the blocking layer 12 and the insulation material 40 are further removed from the epitaxy structure 30 by another etching or other methods, whereby the channels 300 in the epitaxy structure 30 are restored and exposed.
The protective layer 80 is then fully removed to expose the transition layer 60 , the reflective layer 50 and the base 70 as shown in FIG. 14 .
As shown in FIG. 15 , multiple pairs of first and second electrodes 38 , 39 are formed on the blocks of the epitaxy structure 30 and the base 70 , respectively. Each first electrode 38 is made on a bottom face of the first semiconductor layer 32 , and a corresponding second electrode 39 is made on the top face of the base 70 .
As shown in FIG. 16 , finally, the reflective layer 50 together with the transition layer 60 and the base 70 , is cut to form a plurality of individual chips along the channels 300 .
Since the original Si substrate 10 is removed and the reflective layer 50 is incorporated to the chip, the light extracting efficiency of the chip is enhanced. Furthermore, the metal base 70 can timely absorb much more heat from the epitaxy structure 30 , thereby ensuring normal operation of the chip.
It is believed that the present disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the present disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments.
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A method for manufacturing light emitting chips includes steps of: providing a substrate having a plurality of separate epitaxy islands thereon, wherein the epitaxy islands are spaced from each other by channels; filling the channels with an insulation material; sequentially forming a reflective layer, a transition layer and a base on the insulation material and the epitaxy islands; removing the substrate and the insulation material to expose the channels; and cutting the reflective layer, the transition layer and the base to form a plurality of individual chips along the channels.
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[0001] This application claims the priority of Korean Patent Application No. 2003-84732, filed on Nov. 26, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor package, and more particularly, to a stack type semiconductor package in which a plurality of semiconductor chips are mounted.
[0004] 2. Description of the Related Art
[0005] Semiconductor manufacturers have developed methods to increase integration and reduce the size of semiconductor devices. However, since research has to be carried out and investment in equipment must be made to increase integration of the semiconductor devices, the overall manufacturing cost of the semiconductor devices increases. For example, for manufacturing semiconductor memory devices, a large number of technical problems must be solved in the wafer manufacturing process and new equipment must be developed to increase from 64 MDRAM to 256 MDRAM.
[0006] The development of semiconductor packages has provided a method of increasing the integrity without requiring technical development and investment in equipment since a semiconductor package includes a plurality of semiconductor chips without increased integration. Manufacturing the semiconductor package by mounting a plurality of semiconductor chips requires less effort to increase integration than to increase integration during the wafer manufacturing process. For example, it is possible to manufacture a 256 MDRAM by assembling a semiconductor package that includes four 64 MDRAM semiconductor chips.
[0007] Initially, methods of manufacturing a semiconductor package included horizontally arranging the semiconductor chips so that the size of the semiconductor package was not reduced. However, most multi-chip type semiconductor packages are now manufactured by vertically arranging the semiconductor chips.
[0008] Micron Technology, Inc. developed a method of manufacturing a semiconductor package by vertically stacking single semiconductor chips, which is included in U.S. Pat. No. 6,569,709, entitled “Assemblies Including Stacked Semiconductor Devices Separated a Distance Defined by Adhesive Material Interposed Therebetween, Packages Including the Assembly, and Method”.
[0009] FIGS. 1 and 2 are sectional views of conventional stack type semiconductor packages.
[0010] Referring to FIG. 1 , a sectional view of a ball grid array (BGA) package 10 using solder balls 14 as external connection terminals is shown. Here, first and second semiconductor chips 30 a and 30 b are vertically stacked on a substrate 20 using a conventional die adhesive 36 . To manufacture the BGA package 10 , the first semiconductor chip 30 a is mounted on the substrate 20 using an adhesive tape 26 , and bond pads 34 on the first semiconductor chip 30 a are electrically connected by first wires 38 a to bond fingers which are contact units 24 on the substrate 20 . Thereafter, the conventional die adhesive 36 is sprayed, and the second semiconductor chip 30 b is adhered to the conventional die adhesive 36 . Then, the bond pads 34 on the second semiconductor chip 30 b and the contact units 24 on the substrate are connected by second wires 38 b . Finally, the resultant structure is sealed using an epoxy mold compound (EMC) as a sealing resin 40 .
[0011] Conventionally, when the sizes of the first semiconductor chip 30 a and the second semiconductor chip 30 b are the same, the first semiconductor chip 30 a and the second semiconductor chip 30 b are adhered using the die adhesive 36 , which has a bulk modulus less than 1 GPa. However, since the die adhesive 36 covers the interconnection areas of the first wires 38 a on the first semiconductor chip 30 a , the reliability of the BGA package 10 is lowered, as explained below.
[0012] Since the coefficients of thermal expansion of the die adhesive 36 , the first wires 38 a , and the first and second semiconductor chips 30 a and 30 b are different, the reliability is lowered when the temperature of electric equipment included in the BGA package 10 changes. Thus, the first wires 38 a are broken at the bond pads on which the first wires 38 a are connected to the first semiconductor chip 30 a . When the first wires 38 a break, electrical connections are broken, and the BGA package 10 cannot operate properly.
[0013] A temperature cycle test is a test for determining the reliability of a semiconductor package. In the test, the temperature of the semiconductor package fluctuates between a temperature of −55° C. and 125° C. during a time span of 30 minutes a predetermined number of times. As a result, the operation of the semiconductor package over a range of temperatures is determined.
[0014] In a study of 126 BGA packages with the die adhesive having a bulk modulus less than 1 GPa, when the 126 units of BGA packages were temperature cycle tested 150 times, none of the BGA packages failed, 2 units failed after 300 times of temperature cycle tests, 13 units of BGA packages failed after 600 times of temperature cycle tests, and 56 units of BGA packages failed after 1,000 times of temperature cycle test.
[0015] Semiconductor packages to be used in special situations, such as space engineering or military operations, should not fail, even when the temperature cycle test is performed more than 1,000 times. However, about 46% of the BGA packages using the conventional die adhesive failed after 1000 times. Accordingly, the BGA package using the conventional die adhesive cannot be used in situations in which the temperature has large fluctuations.
[0016] Referring to FIG. 2 , in order to improve the reliability of the BGA package 10 , the die adhesive 36 is not extended to the first wire interconnection areas, which is denoted by A in FIG. 2 . Instead, the first wire interconnection areas are filled with the sealing resin 40 , such as the EMC, which has excellent adhesive strength and hardness. However, in this case, it is difficult to precisely control the amount, the viscosity, and the expansion of the die adhesive 36 on the first semiconductor chip. Accordingly, additional processes are required, and it is difficult to manufacture the BGA package 10 ′. Furthermore, when the bond pads are formed at the center of the semiconductor chip, as illustrated in FIG. 3 , it is difficult to apply the die adhesive while avoiding the first wire interconnection areas.
SUMMARY OF THE INVENTION
[0017] The present invention provides a highly reliable stack type semiconductor package which prevents electric disconnection at wire interconnection areas.
[0018] According to an aspect of the present invention, there is provided a highly reliable stack type semiconductor package, comprising a basis frame of the semiconductor package, a first semiconductor chip mounted on the basis frame by using a first die adhesive, first wires, which connect bond pads on the first semiconductor chip to contact units on the basis frame, a second die adhesive having a bulk modulus greater than 1 GPa, which is formed on the first semiconductor chip having the first wires while being expanded to the edges of the first semiconductor chip, a second semiconductor chip attached to the first semiconductor chip by using the second die adhesive, second wires, which connect bond pads on the second semiconductor chip to the contact units on the basis frame, and a sealing portion, which seals the upper portion of the basis frame on which the second semiconductor chip and the second wires are formed.
[0019] The basis frame may be one selected from a lead frame and a printed circuit board, and the first semiconductor chip may be one selected from a semiconductor chip on which bond pads are formed at the center and a semiconductor chip on which bond pads are formed at the edges.
[0020] The type of the stack type semiconductor package may be one selected from a small outline package (SOP), a quad flat package (QFP), a ball grid array (BGA) package, and a chip scale package (CSP), and the stack type semiconductor package may further include a third semiconductor chip mounted on the second semiconductor chip while having the same structure as the second semiconductor chip. In addition, the stack type semiconductor package may further include a heat sink, which efficiently radiates heat to the outside.
[0021] According to another aspect of the present invention, there is provided a stack type semiconductor package having high reliability comprising a substrate used as a basis frame of the semiconductor package; a first semiconductor chip mounted on the substrate by using a first die adhesive; first wires, which connect bond pads on the first semiconductor chip to contact units on the substrate; a second die adhesive having the bulk modulus greater than 1 GPa, which covers first wire interconnection areas on the first semiconductor chip; a third die adhesive, which completely covers the surface of the first semiconductor chip on which the second die adhesive is coated, while having a height greater than the height of the first wires; a second semiconductor chip mounted on the first semiconductor chip by using the third die adhesive; second wires, which connect bond pads on the second semiconductor chip to contact units on the substrate; and a sealing resin, which completely seals the second wires and the second semiconductor chip on the substrate.
[0022] The size of the second semiconductor chip may be the same as or greater than that of the first semiconductor chip. In addition, the bulk modulus of the second die adhesive may be measured at a temperature of 0 C.
[0023] Accordingly, the stack type semiconductor package has high reliability by using the die adhesive with a bulk modulus greater than 1 GPa, so that the first wires are prevented from being electrically disconnected, even during extreme temperature changes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
[0025] FIGS. 1 and 2 are sectional views of a conventional stack type semiconductor package;
[0026] FIG. 3 is a sectional view of a stack type semiconductor package according to a first embodiment of the present invention;
[0027] FIG. 4 is a sectional view of a stack type semiconductor package according to a second embodiment of the present invention;
[0028] FIG. 5A is a plan view of a semiconductor chip included in the stack type semiconductor package of FIG. 3 ;
[0029] FIG. 5B is a plan view of a semiconductor chip included in the stack type semiconductor package of FIG. 4 ;
[0030] FIG. 6 is a sectional view of a stack type semiconductor package according to a third embodiment of the present invention;
[0031] FIG. 7 is a sectional view of a stack type semiconductor package according to a fourth embodiment of the present invention;
[0032] FIG. 8 is a sectional view of a stack type semiconductor package according to a fifth embodiment of the present invention; and
[0033] FIG. 9 is a sectional view of a stack type semiconductor package according to a sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.
[0035] FIG. 3 is a sectional view of a stack type semiconductor package 100 A according to a first embodiment of the present invention.
[0036] Referring to FIG. 3 , a stack type semiconductor package 100 A includes a basis frame 102 , which is formed of a lead frame and a substrate, a first semiconductor chip 120 a , first wires 110 a , a second die adhesive 140 , a second semiconductor chip 120 b , second wires 110 b , and a sealing portion 130 . The first semiconductor chip 120 a is mounted on the basis frame 102 using a first die adhesive 106 . The first wires 110 a connect bond pads 122 , which are formed near the center of the first semiconductor chip 120 a , with contact units 104 on the basis frame 102 . The second die adhesive 140 is formed on the first semiconductor chip 120 a on which the first wires 110 a are formed, and the second die adhesive 140 is expanded to the edges of the first semiconductor chip 120 a . Here, the bulk modulus of the second die adhesive 140 is greater than 1 GPa. The second semiconductor chip 120 b is mounted on the first semiconductor chip 120 a using the second die adhesive 140 . The second wires 110 b connect bond pads 124 on the second semiconductor chip 120 b with the contact units 104 on the basis frame 102 . The sealing portion 130 seals the second semiconductor chip 120 b and the second wires 110 b on the upper surface of the basis frame 102 .
[0037] The semiconductor package 100 A can be used as a small outline package (SOP), a quad flat package (QFP), and a chip scale package (CSP) as well as a BGA package that uses solder balls 150 as external connection terminals.
[0038] The basis frame 102 of the semiconductor package can be a lead frame or a printed circuit board (PCB). In addition, the basis frame 102 can be a substrate used in the BGA package, which is either a flexible substrate including circuit patterns that is made of polyimide or a rigid substrate including circuit patterns that is made of FR-4 resin. Adhesive tapes or an epoxy may be used as the first die adhesive 106 . The first and second wires 110 a and 110 b are ball bonded to the bond pads 122 , 124 of the first and second semiconductor chips 120 a and 120 b and are stitch bonded to the contact units 104 on the basis frame 102 . However, the first and second wires 110 a and 110 b may also be stitch bonded to the bond pads 122 , 124 of the first and second semiconductor chips 120 a and 120 b , respectively, and ball bonded to the contact units 104 on the basis frame 102 .
[0039] The bulk modulus of the second die adhesive 140 is greater than 1 GPa at a temperature of 0° C., and the second die adhesive 140 is expanded to the edges of the first semiconductor chip 120 a to fill the interconnection areas of the first wires 110 a . Here, the bulk modulus is the value representing the coefficient of elasticity against tensile force. In addition, the modulus characteristic represents the ratio of tensile force to transformation.
[0040] If the second die adhesive was made of the same material as the die adhesive included in the conventional semiconductor package which has a bulk modulus less than 1 GPa, the second die adhesive 140 could not absorb the stress caused by thermal expansion and thermal contraction of the first wires 110 a , the second die adhesive 140 , and the first and second semiconductor chips 120 a and 120 b . However, the second die adhesive 140 used in the first embodiment has a bulk modulus greater than 1 GPa, and sufficiently absorbs the stress. Accordingly, the first wires 110 a are not removed from the bond pads 122 of the first semiconductor chip 120 a when the temperature fluctuates.
[0041] It is preferable that the size of the second semiconductor chip 120 b is the same as or greater than the size of the first semiconductor chip 120 a . The sealing portion 130 can be substituted by a ceramic, an encapsulant, or a metal cap instead of the epoxy mold compound (EMC), which can seal the substrate 102 on which the second semiconductor chip 120 b and the second wires 110 b are formed. Thus, even if the bond pads 122 on the first semiconductor chip 120 a are formed near the center of the first semiconductor chip 120 a , the first and second semiconductor chips 120 a and 120 b can be easily stacked.
[0042] FIG. 4 is a sectional view of a stack type semiconductor package 100 B according to a second embodiment of the present invention.
[0043] Referring to FIG. 4 , the semiconductor package 100 B is similar to the semiconductor package 100 A, except that bond pads 122 ′ are formed at the edges of a first semiconductor chip 120 a ′. Accordingly, further description of the semiconductor package 100 B will be omitted.
[0044] FIGS. 5A and 5B are plan views of the semiconductor chips used in the semiconductor packages 100 A and 100 B of FIGS. 3 and 4 , respectively.
[0045] Referring to FIG. 5A , the semiconductor chip 120 a includes the bond pads 122 disposed near the center. In FIG. 5B , the semiconductor chip 120 a ′ includes the bond pads 122 ′ near the edges. Both the semiconductor chips 120 a and 120 a ′ include an active region on which circuits are formed.
[0046] FIG. 6 is a sectional view of a stack type semiconductor package 100 C according to a third embodiment of the present invention.
[0047] Referring to FIG. 6 , the semiconductor package 100 C additionally includes a heat sink 160 , which is not included in the semiconductor package 100 B, below the first die adhesive 106 in order to efficiently extract heat from the first and second semiconductor chips 120 a ′ and 120 b . The material included in, the location of, and the shape of the heat sink 160 can be varied.
[0048] FIG. 7 is a sectional view of a stack type semiconductor package 100 D according to a fourth embodiment of the present invention.
[0049] Referring to FIG. 7 , the semiconductor package 100 D is identical to the semiconductor package 100 B, except that the semiconductor package 100 D further includes a third semiconductor chip 120 c . The third semiconductor chip 120 c is stacked by the same method as the second semiconductor chip 120 b . Only three semiconductor chips, 120 a , 120 b , and 120 c , are stacked in the semiconductor package 100 D, but the number of the semiconductor chips can be greater.
[0050] FIG. 8 is a sectional view of a stack type semiconductor package according to a fifth embodiment of the present invention.
[0051] Referring to FIG. 8 , the semiconductor package 100 E is an SOP type semiconductor package. Accordingly, a lead frame 102 that includes a die pad 164 and a lead 162 is used as a basis frame. The remaining structure, including the mounted first and second semiconductor chips 120 a and 120 b , the first and second wires 110 a and 110 b , and the sealing of the first and second semiconductor chips 120 a and 120 b and the first and second wires 110 a and 110 b using the sealing portion 130 is the same as that in the semiconductor package 100 B. The structure of the semiconductor package 100 B can be applied to a QFP or a CSP semiconductor package.
[0052] FIG. 9 is a sectional view of a stack type semiconductor package 200 according to a sixth embodiment of the present invention.
[0053] Referring to FIG. 9 , the stack type semiconductor package 200 includes a substrate 202 , a first semiconductor chip 220 a , first wires 210 a , a second die adhesive 240 , a third die adhesive 270 , a second semiconductor chip 220 b , second wires 210 b , and a sealing resin 230 . Here, the substrate 202 is used as the basis frame of the semiconductor package 200 . The first semiconductor chip 220 a is mounted on the substrate 202 using a first die adhesive 206 . The first wires 210 a connect bond pads 222 on the first semiconductor chip 220 a with contact units 204 on the substrate 202 . The second die adhesive 240 has a bulk modulus greater than 1 GPa and covers the interconnection areas of the first wires 210 a on the first semiconductor chips 220 a . The third die adhesive 270 completely covers portions of the first semiconductor chip 220 a on which the second die adhesive 240 is not coated, with the height of the third die adhesive 270 greater than the height of the first wires 210 a . The second semiconductor chip 220 b is stacked on the first semiconductor chip 220 a using the first and the third die adhesives 240 , 270 . The second wires 210 b connect the bond pads 224 on the second semiconductor chip 220 b with the contact units 204 on the substrate 202 . The sealing resin 230 seals the second wires 210 b and the second semiconductor chip 220 b onto the substrate 202 .
[0054] In the semiconductor package 200 , the second die adhesive 240 with the bulk modulus greater than 1 GPa, which prevents the first wires from breaking, is applied to the first wire interconnection areas while not being applied to the entire surface of the first semiconductor chip 220 a . Here, the height of the second die adhesive 240 should be such that the interconnection areas of the first wires 210 a (i.e., ball bonds) are covered. In addition, a die adhesive with a bulk modulus less than 1 GPa can be used as the third die adhesive 270 .
[0055] The substrate 202 may be formed by a flexible substrate or a rigid substrate. The bond pads 222 may be formed at the center of the first semiconductor chip 220 a or at the edges of the first semiconductor chip 220 a , as shown in FIGS. 5A and 5B . It is preferable that the size of the second semiconductor chip 220 b is the same as or greater than the size of the first semiconductor chip 220 a . The sealing resin 230 can be a ceramic, an encapsulant, or a metal cap, as well as the EMC. The semiconductor package 200 may further include a heat sink, as included in the semiconductor package 100 C and may include a third semiconductor chip, as included in the semiconductor package 100 D. In addition, the semiconductor package 200 may be part of a SOP, QFP or CSP package as shown in the fifth embodiment of the present invention, instead of the BGA package. It is preferable that the bulk modulus of the second die adhesive 240 be measured at a temperature of 0° C. The stack type semiconductor package 200 may include solder balls 250 , which are attached to the lower portion of the substrate 202 , as external connection terminals.
[0056] In order to determine the effectiveness of the semiconductor package according to the embodiments, the BGA package 100 B according to the second embodiment was used as a sample in a temperature cycle test. The conditions of the temperature cycle test were the same as the conditions of the temperature cycle test described in connection with the conventional semiconductor package.
[0057] The test performed on the BGA package 100 B found that no defects were detected, even when temperature fluctuated between extreme temperatures 150 times, 300 times, 600 times, and 1,000 times.
[0058] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the 25 spirit and scope of the present invention as defined by the following claims.
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A highly reliable stack type semiconductor package, which does not have a problem of interconnection areas becoming disconnected due to thermal expansion. The semiconductor package includes a second die adhesive, which is formed between a first semiconductor chip and a second semiconductor chip, applied to the upper surface of the first semiconductor chip, and extends to the wire forming units. The second die adhesive is selected to have a bulk modulus greater than 1 GPa to prevent electric disconnection due to breakage of wires in the stack type semiconductor package during thermal stress.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a related case to U.S. Application Ser. No. 168,055 as filed on July 14, 1980 and entitled "Method and Apparatus for Shear Wave Logging", now U.S. Pat. No. 4,369,506 as issued on Jan. 18, 1983.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to shear wave acoustic logging of boreholes and, more particularly, but not by way of limitation, it relates to an improved method and apparatus for obtaining shear wave data utilizing longer wavelength source frequencies.
2. Description of the Prior Art
The prior art includes numerous types of shear wave logging tool as they have been used for a number of years in obtaining shear wave data from a borehole in the earth's surface. Shear wave generation sources have been utilized both from a position on the earth's surface adjacent the borehole and from the logging tool itself, i.e. the source is an integral part of the tool. In most prior art shear wave applications the generation source has been controlled within higher frequency ranges, e.g. 10-15 kilohertz, and both shear wave source and detectors were positioned in close coupling contact with the borehole wall in order to provide optimum detection of the shear wave energy. The prior art applications tended toward higher frequency source energies which tended to see the well bore from a microscopic point of view in that a relatively small portion of the well adjacent to the logging tool is seen to vibrate under the influence of those shear wave vibrations whose wavelength is smaller than the bore diameter. Due to this then, depth of penetration or examination by the acoustic waves is limited to the rock structures closely surrounding the borehole.
SUMMARY OF THE INVENTION
The present invention relates to an improved method and apparatus for obtaining subsurface shear wave velocities. The invention utilizes longer wavelengths at lower frequencies and, therefore, gives a better representation of the rock properties at a greater distance away from the potentially disturbed well bore. Thus, the tool of the present invention sees the well bore from a macroscopic point of view in that the entire well bore is visualized as oscillating under the influence of transverse horizontal shear wave vibrations whose wavelength is large compared to the well bore diameter. The invention utilizes a sensor or tubular tool that is designed to move sympathetically with the vibrating borehole to thus give a true representation of the downward traveling shear wave that causes the borehole to oscillate. The tool includes two or more horizontal geophone pairs, each pair oriented at 90° displacement, and the tool is filled with air to provide for weight adjustability relative to the borehole fluid. Horizontal shear waves are then generated at the surface in the 10-300 hertz range such that the mono-frequency shear wave disturbance traveling past the sensors may be detected and phase compared to obtain an indication that relates to the velocity of shear wave travel in the earth adjacent the borehole.
Therefore, it is an object of the present invention to provide a method of obtaining more reliable shear wave velocity data relative to a fluid-filled borehole and the surrounding strata.
It is also an object of the present invention to provide an improved type of shear wave detection tool which is sympathetic to the contortional movements of the borehole when under shear wave stresses.
It is yet another object of this invention to provide a borehole shear wave detector which provides greater indication of shear wave velocity through a greater volume of the surrounding earth structure.
Finally, it is an object of the present invention to generate and detect lower frequency horizontal shear waves which convey more accurate data relative to the rock properties of the surrounding strata.
Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial block and schematic illustration of the logging tool and surface processing equipment of the present invention;
FIG. 2 is a view in idealized form of a shear wave logging tool suspended in a borehole formed in the earth's surface;
FIG. 3 is an idealized view of the shear wave logging tool and borehole when under stress due to generation of horizontal shear waves at the surface;
FIG. 4 illustrates the phase relationship of detected horizontal shear waves; and
FIG. 5 is a vertical section of a particular logging sonde structure for utilization in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates schematically a logging tool 10 as it would be suspended in operative association with a borehole structure. The tool 10 consists primarily of a selected size of metal tubing 12 defining an internal cavity 13 and having the upper and lower ends sealingly closed by geophone housings 14 and 16, respectively. Optionally, additional spaced horizontal geophone housings, such as housing 18, may be utilized to provide additional shear wave data output.
The geophone housings such as 14, 16 are a standard form of sealed structure for containing conventional types of horizontally polarized geophone 20 and 22 in proper attitude and support for detecting horizontal wave motion. Any additional geophones 24 will be similarly mounted at selected spacing and provided with necessary electrical connection to the surface processing equipment. The lowermost geophone housing 16 includes an eye bolt suitably affixed therebeneath, as by welding, in adaptation to receive a cable 28 which, in turn, is connected to an anchor bolt 30 for receiving a selected plurality of weights 32.
Upper geophone housing 14 is similarly secured to an eye bolt 34 which serves for affixure of suspension cable 36 extending down the borehole from a suitable surface winch 38. Detected output from geophone 22 may be conducted via leads 40 and up through suspension cable 36 as is common practice using standard logging cable. In like manner, geophone 20 is provided with surface-connecting leads 42 and similar leads would be provided for additional geophones, such as an optionally employed geophone 24.
Electrical outputs from the geophones are then taken off of logging cable 36 for input to a phase amplitude meter 44 which provides further output to a display 46 and/or suitable digital computer or microprocessor circuitry 48. There are various forms of suitable phase amplitude meter 44 which are commercially available; however, present application utilizes a phase amplitude meter as manufactured by Hewlett-Packard Corporation of Palo Alto, Calif. Output display 46 may take any of the various forms utilized in geophysical field work such as photographic, chart recorder and other equivalents.
Referring now to FIG. 2, there is illustrated a borehole 50 as formed in earth surface 52 and filled with fluid 54, i.e. water, mud or the like. The shear wave tool 10 is then suspended from a suitable winch 38 by logging cable 36 and positioned downhole adjacent selected strata. A horizontal shear wave source 56 may then be coupled on the earth's surface 52 proximate to or within the borehole 50. Referring also to FIG. 3, an exaggerated illustration, the shear wave source 56 is energized at a selected frequency within the range of 10-300 hertz, frequencies having wavelengths much longer than the characteristic dimensions of the borehole 50, and the tendency is to cause a contortion of the borehole as indicated. The horizontal shear wave source 56 may be any suitable form of controlled frequency source such as a vibrator or the like which provides reliable frequency of energy input to the earth surrounding the borehole.
FIG. 4 illustrates the manner in which horizontal geophones 20 and 22 located at spacing d (FIG. 1) generate phase-displaced signal outputs for comparison by phase amplitude meter 44. Thus, geophone 20 detects horizontal shear wave signal 60 as shown on base line 62, and the lower or more remote geophone 22 detects a shear wave signal 64 as shown on base line 66 in phase displaced relationship. Thus, the phase delay .0., as illustrated by dash lines 68, 70, provides a quantity which can be directly related to shear wave velocity in the surrounding medium when the frequency of propagation is known. Should additional geophones 24 or the like be employed, similar phase differentials can be derived by phase amplitude meter 44 for comparison to other data and further verification of the shear wave velocity in the surrounding medium.
In operation, the cavity 13 is maintained air-filled in order to achieve a selected buoyancy characteristic which will allow the non-coupled tool 10 to be suspended for movements sympathetic to the vibrational contortions of borehole 50, thereby to achieve maximum detector output and more concise signal phase definition. The buoyancy caused by air-filled cavity 13 is then offset to achieve a near neutral buoyancy in the borehole fluid by addition of a selected number of weights 32 on anchor bolt 30. The number and size of weights will depend upon the density of the borehole fluid and the conditions of the borehole fluid and the borehole wall. The weight 32 and tool assembly 10 is then lowered into the borehole as suspended by cable 36 to a designated depth and the horizontal shear wave source 56 is operated to provide shear wave input to the earth and propagation through the medium surrounding the borehole. The motion of the vibrating borehole is then sensed by two or more horizontal geophones 20, 22 as spaced apart by a distance d with output of the sensed voltage indication transmitted up to phase amplitude meter 44 at the surface station. For any continuous, monofrequency shear wave disturbance traveling past the sensor, the output frequency of the geophones will be identical except that a phase difference .0. will be seen between the two geophone outputs, as shown in FIG. 4. This phase difference is given by the well known expression:
.0.=2 π/λ·d
where .0. is the phase angle difference between the geophone outputs of geophone 20 and 22, λ is the wavelength of the downward traveling shear wave, and d is the spacing between the geophones. Thus, by measuring the difference in phase and knowing the spacing d, the wavelength of the shear wave can be readly determined. Thereafter, frequency f being known, the actual shear wave velocity V is terminable by simple conversion using:
V=fλ.
The logging tool may be intermittently lowered to successively deeper strata along the borehole 50, each time energizing the shear wave source 56 and analyzing the detected shear wave data through phase amplitude meter 44 to detect phase difference. The digital phase difference output may then be applied to display 46 as well as computer 48, e.g. a simple microprocessor, to effect shear velocity conversion and subsequent recording, e.g. as shear wave velocity log.
FIG. 5 illustrates a particular type of logging sonde 80 that is effective for use in the manner of the present invention. The sonde 80 is formed by a length of cylindrical tubing 82 as formed from steel and having sufficient wall thickness to enable fastener gripping. The upper end of tubing 82 is sealingly closed off by an end cap 84 that is securely affixed as by threads to a logging tool head member 86. The logging tool head 86 is of conventional type and adapted to be attached to a standard wire line or logging cable as by threaded post 88. The end plug 84 is threadedly secured within a central bore 90 of a cylindrical geophone housing member 92 that is adapted to be closely received within the central bore 94 of frame tubing 82. Alternatively, the end cap 84 and housing member 92 may be unitarily formed. Peripheral packing or sealing member 96 is disposed within a suitable seating 98 about the upper, inner circumfery of frame tubing 82 in coactive engagement with the outer circumfery of geophone housing 92. An axial bore 100 is formed through end plug 84 to allow passage of conduits between the logging cable and transducing members within the sonde 80. The geophone housing 92 is maintained in secure engagement within frame tubing 82 by means of a plurality of set-screw type fasteners 102 spaced about the periphery of frame tubing 82.
A circumferential groove 104 is disposed around geophone housing 92 to receive an O-ring type seal 106 seated therein and providing a pressure seal adjacent the inner circumfery of frame tubing 82. Further internally from seal 106 there are formed first and second transverse bores 108 and 110 in close proximity but disposed at 90° each to the other. First and second horizontal geophones 112 and 114 are then disposed in respective bores 108 and 110 in parallel orthogonal disposition. Each of horizontal geophones 112 and 114 is connected by wire conductor, shown generally as connectors 116, to convey data uphole to the surface control and processing station. Suitable feed-through bores, e.g. bore 118, are provided through internal components along the sonde to allow interconnection.
The lower end of sonde 80 includes a similar formation consisting of a bottom nose cone 120 in combination with a lower geophone housing 122. The nose cone 120 may be screw fastened within a threaded bore 124 formed axially in geophone housing 122, and the entire assembly is maintained in secure placement by a plurality of set-type screw fasteners 126 surrounding the frame tubing 82. Here again, cone 120 and housing 122 may be unitarily formed. A sealing member 128 is peripherally seated about the lower end of frame tubing 82, and an O-ring seal 130 within a circumferential groove 132 provides pressure seal for the interior of sonde 80. Above seal 130 there are disposed third and fourth bores 134 and 136 formed in parallel orthogonal disposition through geophone housing 122 in order to receive horizontal geophones 138 and 140 securely therein. Electrical connection of lower geophone 138 and 140 is made by conventional wire interconnection such as connectors 142 and feed-through bores 144. The individual geophones may be secured in their respective bores by means of suitable bonding agent, potting compound or the like so long as they are held tightly in horizontal attitude for vibration sensing.
The internal cavities of sonde 80 are air-filled and maintained in sealed disposition. Therefore, buoyancy off-set weighting may be carried out by such as an external cylindrical sleeve 146 that is slidable over the outer circumfery of frame tubing 82 and securely fastened thereon by means of a plurality of circumferentially spaced set-type screw fasteners 148. The weighting sleeve 146 may be formed from such as steel to be of preselected length and wall thickness so as to impart a specified counterweight. Weighting sleeves 146 may be varied in accordance with the exigencies of the particular logging operation. Also, weighting may be effected in the manner shown in FIG. 1. Of course, in accordance with the practice of the present invention, it is desirable for sonde 80 to be of relatively long length in order to enable sufficient phase displacement as between waves detected at the upper and lower geophone pairs. Also, it is contemplated that three or more geophone pairs in respective housing members may be disposed along a sonde frame to enable particular specialized logging effects.
The foregoing discloses a novel form of shear wave detection tool which can exhibit a selected degree of buoyancy within a borehole fluid, and which does not require hydraulic or electric packer equipment and/or actuatable extensors for coupling the detection apparatus to the borehole wall. In particular, the sonde design allows for more accurate sensing of borehole flexure during shear wave propagation as the sonde moves sympathetically with the borehole wall. The orthogonally disposed horizontal geophone pairs are effective to detect shear waves and to give a true representation of downward traveling wave energy as the borehole oscillates.
It should be understood that changes may be made in combination and arrangement of elements as heretofore set forth in the specification and shown in the drawings; it being understood that changes may be made in the embodiments disclosed without departing from the spirit and scope of the invention as defined in the following claims.
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Apparatus for shear wave logging of formations adjacent a borehole wherein a tubular apparatus is specifically constructed for sympathetic movement with the borehole in response to low frequency horizontal shear waves. The apparatus consists of tubular frame structure with end members including housings for rigid seating of orthogonal pairs of horizontal wave detectors. Outer sleeve structure may be utilized for buoyancy adjustment.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to marking and highlighting text in a publication. More specifically, the present invention relates to a system and method of marking and highlighting text and/or graphics of a publication without impairing legibility of the same and while allowing removal of such highlighting in a non-destructive manner.
[0003] 2. State of the Art
[0004] Marking and highlighting text in publications, such as for example, text books, periodicals, or religious texts, is widely practiced. Such marking and highlighting typically involves the use of colored markers, such as pens, pencils, felt type markers, or wax based markers, to underscore or overlay the text or graphics causing the highlighted portion of a particular page stand out. By highlighting a particular section of a publication the reader thereof may more effectively refer back to the highlighted text or graphic for refreshing, quick review, or occasional reference without the need to laboriously search through the pages of text in an effort to find the desired information.
[0005] The use of such highlighters and markers in academic, professional, and personal study can be quite extensive, and often results in individuals utilizing multiple colors of highlighters to organize their studies by category of information. As an example, a medical student or practitioner might highlight or mark a text containing information on specific diseases or ailments for future reference. In doing so, the individual might mark or highlight symptoms of the disease in a first color, effects of the disease in a second color, and possible treatments of the disease in a third an separate color. Thus, the user of the publication may customize the information according to his or her own liking and preference for organization. Of course, this type of technique or method of marking is often utilized in other topics or areas of study as well.
[0006] Such practices are common because of their aid in efficiently learning and recalling information during the study and practice of various academic disciplines. As noted before, the practice of highlighting text is also common among those conducting personal studies such as the study of religious texts. However, while the practice of highlighting and marking publications is widely known and utilized, the current state of the art suffers from various drawbacks and inconveniences.
[0007] One such drawback is that many current markers and highlighters, such as those described above, are typically used to deposit ink onto a page of the publication. The use of ink creates a permanent mark in the publication which may not be removed or relocated once it has been applied to the publication. Additionally, the use of ink often causes “bleeding” to the opposite side of the page, particularly when the page is made from a light or fine grade of paper. Likewise, the ink may be inadvertently transferred to a facing page once the publication is closed, or possibly smear to adjacent sections of text not previously highlighted. Smearing and bleeding not only leave unwanted permanent marks in the publication, but also lead to inefficiencies since various passages of the publication appear to have been marked when, in fact, the passage which was actually marked occurs elsewhere such as on the back side of the page, or possibly on a facing page. Such problems are not limited to ink based markers or highlighters. Wax based markers may similarly smear or transfer to a facing page.
[0008] Another concern regarding the marking and highlighting techniques mentioned above is that the act of marking or highlighting a passage is one of permanence. Thus, when a student marks a passage in his or her text book, that section remains marked and may not be subsequently changed. This poses several problems. First, students often wish to sell their text books back to the school bookstore at the end of a semester or course. Often, numerous markings and highlighted sections in a book will reduce the buy-back value of the publication. Second, it often occurs that the first time a publication is read a particular passage or section of information will be highlighted. However, the next time the publication is utilized, it may be determined that the originally highlighted section is not as important as originally thought. Alternatively, it may be that, upon the first reading, too much material contained in the publication was highlighted. Having too much or incorrect information highlighted reduces the efficiency of marking a publication and serves to negate the original intentions of doing so.
[0009] Another problem associated with the permanence of current marking and highlighting techniques involves research wherein the publications being studied and searched through are not owned by the reader or researcher. Thus, for example, numerous publications may be compiled with each publication containing specific information important to the research at hand. However, because the publications may have been borrowed, such as from a library, the user will refrain from marking the pertinent information in the publications knowing that such marking and highlighting will deface the material and may detract from subsequent reading or research of the material by another. Thus, such research is often lacking in efficiency due to a reader's inability to mark selected portions of the publication for subsequent reference.
[0010] Additionally, traditional marking implements such as ink based highlighters are generally retained separately from publications, allowing for the inconvenience of misplacing the same. It is often the case, as one goes from studying in a first environment, such as a home, to studying in a second environment, such as the library, that the highlighter is misplaced or forgotten since it is not always retained with the publications. While some attempts have be made to make a highlighter which may be retained with a given publication (for example, see U.S. Pat. No. 5,984,558 issued to Diep), it is unlikely that an individual would desire to retain such a marker with each and every publication which is being studied and marked. Also, such a device as taught by Diep fails to address the issues of permanence and inadvertent marking described above.
[0011] Other attempts have been made to address some of the various issues associated with highlight publications. Some of these attempts have even tried to address the issue of permanent marking and highlighting of publications. However, the attempted solutions have no been without difficulties and drawbacks of their own. For example, one such proposed marking system is disclosed in U.S. Pat. No. 5,409,753 issued to Perez. This system includes a plurality of removable adhesive dots which are placed over a paragraph or verse number in a publication, specifically a bible, adjacent the text of the paragraph or verse. The adhesive dots are retained on a separate card as a part of a kit which is attached to the back of the publication. However, as is well understood by users of such devices, it is often difficult to remove adhesive stickers from their respective backing, which potentially makes the use of such adhesive dots difficult for certain individuals. Additionally, such a system as described by Perez is particularly adapted for use in marking scriptures as is indicated by the disclosure. While attaching a dedicated marking kit to the back, or inside the back cover, of an individual publication which serves as the basis of long term dedicated study serves a purpose, attaching an individual kit to each of a plurality of publications or texts would become a burden to the user and make such publications cumbersome.
[0012] Another highlighting medium is described in U.S. Pat. No. 4,913,946 issued to Sala et al. The highlighter of the Sala patent is described as a fluorescent adhesive tape for application to, and subsequent removal from, a publication. However, Sala describes this highlighter in terms of a roll of a continuous roll of tape from which segments may be removed for highlighting one or more passages of a publication. However, a roll of tape is subject to misplacement just as described above with regard to ink type markers and other similar highlighters. Additionally, carrying a roll of highlighting tape would likely prove more inconvenient than carrying an individual ink or writing type highlighter since a roll of tape having a sufficient quantity thereof is likely to be larger and bulkier. This is especially true since a roll of tape is likely to require an accompanying dispenser which inherently adds to the overall size of the highlighting implement.
[0013] Additionally, the state of the art could be improved with regard to its ability to direct one's attention to specifically marked passages. With increased use of graphics, bold print, and multi color printing implemented in current publications, it becomes necessary to more clearly differentiate a specifically identified or highlighted item of information in a publication from the text and graphics of the publication itself.
[0014] In view of the shortcomings in the state of the art, it would be advantageous to provide a highlighter and highlighting system which is easily removable and which doesn't damage a publication while allowing for unimpaired reading of original text when applied thereto. Additionally, it would be advantageous to provide a highlighter which allows for greater differentiation between the printed page and the specific material selected and marked by an individual. Such a highlighter and system would preferably be simple to use and capable of being easily retained with a publication to avoid loss or misplacement.
BRIEF SUMMARY OF THE INVENTION
[0015] In accordance with one aspect of the invention a publication highlighting implement is provided. The implement includes at least one segment of film having a first surface and a second opposing surface. Adhesive is applied to the first surface of the film segment. The at least one segment is removably adhered to a backing member by means of the adhesive. At least one of the first or second surfaces includes a printed graphic on at least a portion thereof. The film segment is defined by a periphery or a perimeter which includes a scalloped edge along at least a portion of the perimeter, the scalloped edge facilitating easier removal of the segment from the backing as well as from a publication to which it may be applied.
[0016] The backing member may be configured for use as a bookmark and may further include a graphic printed thereon comprising, for example, an advertisement of a local bookstore or other retailer.
[0017] Desirably, the highlighting implement includes a plurality of segments formed and adhered to the backing member. The printed graphics of each segment are configured to overlay printed or textual material and mark or highlight such material without visible degradation of the printed material to a reader thereof viewing the printed material through the segment.
[0018] In accordance with another aspect of the invention, a publication highlighting implement is provided having at least one transparent film segment with first and second opposing surfaces. Adhesive is applied to the first surface of the film segment and a printed graphic is located on at least a portion of the second surface of the film segment. The printed graphic is configured to have a three-dimensional appearance or simulate a three-dimensional object such that it draws a viewer's attention more efficiently to the area of text upon which it is placed upon. The three-dimensional appearing image is formed by varying the ink composition of the graphic in specific areas to render an image of “highlights” and “shadows” thus giving the illusion of depth to the image.
[0019] In accordance with yet another aspect of the invention, a method of manufacturing a publication highlighting implement is provided. The method includes providing a sheet of clear stock film and placing adhesive on a first side of the polyester film. The film is removably adhered to a sheet of backing. The sheet of clear stock film is segregated into a plurality of a segments. In segregating the film into individual segments, a scalloped, sinusoidal or otherwise undulating edge is formed along a portion of each segment. A graphic is also printed on a portion of each segment, the graphic being configured to overlay printed material to mark or highlight it without degrading the readability of the material.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
[0021] [0021]FIGS. 1A and 1B depict a publication highlighting implement according to one embodiment of the invention;
[0022] [0022]FIGS. 2A and 2B depict alternative embodiments of particular aspects of the highlighting implement shown in FIGS. 1A and 1B;
[0023] [0023]FIG. 3 is a perspective view of a publication with which the highlighting implement of FIGS. 1A and 1B is utilized;
[0024] [0024]FIG. 4 is an elevational view of a plurality of highlighting implements in a package according to one embodiment of the invention; and
[0025] [0025]FIG. 5 depicts an alternative embodiment of a particular aspect of the highlighting implement of FIGS. 1A and 1B.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIGS. 1A and 1B, a publication highlighting implement 10 is shown. It is noted that the term “publication,” as used herein, is meant to include any leaf or page having text or graphics thereon. The highlighting implement 10 includes a transparent layer 12 formed of a clear stock film material. Such clear stock material may include, for example, polyester, acetate or MYLAR. While numerous materials may be suitable, polyester has proved to provide durability and a resistance to tearing.
[0027] The transparent layer 12 is relatively thin and desirably has a thickness in the range of 1.0 to 3.0 thousandths of an inch (0.001 to 0.003 in). Adhesive is placed on the back surface 14 of the transparent layer 12 allowing the transparent layer 12 to be removably adhered to a sheet of flexible backing 16 . Alternatively, the adhesive may be placed on the sheet of backing 16 for removable adherence of the transparent layer 12 . An exemplary backing material which may be used includes Flex-O-Backer available from MACtac, located at 4560 Darrow Road, Stow, Ohio 44224.
[0028] The transparent layer 12 is cut or segregated into a plurality of individual segments 18 with each segment being individually removable from the sheet of backing 16 . Each segment 18 includes a printed graphic 20 on a surface thereof. The printed graphic 20 is designed to differentiate an identified passage of text or other information within the publication and thus allow a viewer to easily find and recall the identified information. The graphic 20 may include an arrow, as shown in FIG. 1A, or may include other graphical symbols such as, for example, a quote mark 20 A as seen in FIG. 2A, or an asterisk 20 B as seen in FIG. 2B. Of course other symbols may likewise be utilized and the examples utilized herein should not be viewed as limiting of the invention in any way.
[0029] The graphic 20 may be printed as one or more of various colors with bright colors being more preferable for their quality of quickly attracting the attention of a viewer. Thus, for example yellow, red, green, orange, and other bright colors, and particularly fluorescent variants of such bright colors, help to effectively and efficiently mark and differentiate selected text or information in a publication. The graphic 20 may be printed on either side of the transparent film 12 , or alternatively, the graphic 20 may be printed on both sides of the transparent film 12 . Printing on both sides of the film may allow for added contrast or for a more intense appearance of the graphic. However, if the graphic 20 , or a portion thereof is printed on the back side 14 of the transparent film 12 , it should be printed or otherwise formed prior to placing adhesive thereon.
[0030] The graphic 20 is additionally printed in a manner such that each segment 18 maintains its transparent qualities and may be placed over text or other printed matter without visible degradation of the printed matter. Thus, it is important that each graphic 20 not only be “see through,” but also be “read through” so as to not impair a viewer's ability to read or decipher the information being marked or highlighted by the particular graphic 20 .
[0031] As can be seen in FIG. 1A, as well as FIGS. 2A and 2B, each segment 18 includes a scalloped, or “crinkle-cut” edge 22 . The scalloped edge 22 is formed as a curved edge including an undulating-type pattern along one or more edges of the segment 18 . The scalloped edge 22 assists in removal from both the sheet of backing 16 as well as subsequent removal from a printed publication. When an individual desires to remove a segment 18 from the backing 16 or from a printed publication, they will typically use their fingernail to lift the segment 18 by an edge 22 , and particularly a corner thereof. By forming a scalloped edge 22 there are more extended protrusion points provided along the edge 22 with each protrusion being an effectual “corner” for lifting the segment 18 off of the backing 16 or a publication page. Alternatively, or in addition to lifting the segment by a “corner,” an individual may attempt removal of the segment 18 by slightly bending the backing 16 or publication page to cause an edge 22 of the segment 18 to “lift” therefrom. Oftentimes, the edge 22 of segment 18 will lift easier if one initiates the bend at an angle with respect to the specific edge 22 to be lifted. The scalloped edge 22 effectively provides an edge having a continuously varied angle making it easier to lift the segment 18 from the backing 16 or printed publication regardless of the angle at which one initiates a bend. The scalloped edge 22 may be formed such that numerous protrusions 22 A are formed along a defined edge of a single segment 18 , but desirably includes at least one fully developed protrusion 22 A formed along at least one edge of each individual segment 18 .
[0032] The backing 16 is configured in size and shape such that it may be utilized as a bookmark. Thus, the highlighting implement 10 may be stored with a publication such that it will not be misplaced. Additionally, an individual highlighting implement 10 may be fabricated so as to be relatively inexpensive in comparison with an ink based marker or highlighter thus allowing an individual to easily obtain multiple highlighting implements 10 and retaining one or more with each of a plurality of publications being studied.
[0033] Referring to FIG. 1B, the reverse side of the backing 16 , opposite the plurality of segments 18 , may include a university logo, bookstore name or trademark, or some other institutional advertisement. The structure of the highlighting implement lends itself to a certain level of customization such that any retailer stocking and selling such a highlighting implement 10 may have a customized institutional advertisement printed on the highlighting implement 10 , thus making it more desirable for the retailer to sell such an item.
[0034] Alternatively, the reverse side of the backing 16 may include decorative graphics, outline helps, such as, for example, a periodic table, or other printed matter that makes the highlighting implement more desirable to a retailer and/or a consumer.
[0035] Referring to FIG. 3, use of the highlighting implement 10 in conjunction with a publication 24 is shown. The publication 24 includes a plurality of pages 26 each having text 28 , publication graphics 30 , or other printed information thereon. The highlighting implement 10 may be used as a bookmark for quick identification of a specific page 26 , or may alternatively be inconspicuously placed elsewhere in the publication for retention. Individual segments 18 are removed from the backing 16 of the highlighting implement 10 and placed over sections of text 28 or printed material identified by the reader of the publication 24 . For example the beginning 32 of an identified passage may be marked with a first segment 18 A and the ending 34 of the same passage may be identified with a second segment 18 B. The graphical symbols associated with segments 18 A and 18 B are shown as single quotes which serves to more readily identify the marked text as a complete passage or a single concept. However, other graphics could be utilized in similar manner. Additional segments 18 could be placed within the identified passage for heightened emphasis is so desired. Alternatively, an individual segment 18 may be used to indicate identified material such as is shown with respect to segment 18 C highlighting information adjacent the publication graphic.
[0036] It is noted that the segments 18 A- 18 C are placed over printed material of the publication 24 , such as the printed text 28 . The segment 18 calls attention to the marked text due to its color and graphic printed thereon. However, the text 28 is readable through all portions of the segment 18 including the printed graphic. It is also noted, that the edges (scalloped or otherwise) are not shown in FIG. 3. This is indicative of the present invention being formed of a thin transparent film 12 which allows the segments 18 to be placed on printed matter with only the graphic 20 being substantially differentiable from the printed matter itself. Thus the edges of the segment 18 , as well as any portion of the segment not having a graphic or other matter printed thereon is essentially undetected, furthering the ability of the inventive highlighting segments 18 to call attention to specific information without any extraneous structure which may be unsightly or detracting.
[0037] However, it is noted that the present invention may alternatively include a thin transparent film 12 which allows a slight amount of perceived differentiation between the segment 18 and the publication 24 . Such would allow a user to more easily locate one or more edges, including the scalloped edge 22 , for subsequent removal of the segment from the publication 24 .
[0038] Referring briefly to FIG. 4, a plurality of highlighting implements 10 is shown in exemplary packaging 50 as may be utilized for containing the highlighting implements 10 during transport and display by a retailer, as well as for storing the highlighting implements 10 when not in use. The packaging 50 may be formed as a sleeve with an opening 52 at one end for insertion and removal of the highlighting implements 10 . The packaging 50 may additionally be formed of a clear plastic material such that the highlighting implements 10 are viewable while contained therein.
[0039] The packaging may further include a tab 54 which is foldable and insertable into the opening 52 . The tab 54 thus serves to close the packaging such that the highlighting implements 10 are securely contained within the packaging 52 . Additionally, an aperture 56 may be formed in the tab 54 for hanging or otherwise displaying the packaging 50 and highlighting implements 10 in a retail establishment. The packaging 50 may contain a sufficient number of highlighting implements 10 , for example 5 or 10, while still maintaining a thin profile such that the packaging 50 and plurality of highlighting implements 10 may be stored in a publication without causing the publication to become unduly bulky.
[0040] Referring now to FIG. 5, an alternate graphic 20 C is shown which may be incorporated with the highlighting implement 10 disclosed herein. The graphic 20 C is shown as an arrow, but, as apparent to those of ordinary skill in the art, the various aspects of the disclosed graphic 20 C are applicable to other symbols as well. The graphic 20 C may be discussed as having multiple zones or regions. A first zone 40 is generally centrally located and is of a specified color having a first level of intensity in appearance. A first set of multiple regions 42 are located generally along the upper and trailing edge of the graphic 20 C and exhibit an appearance of the same general color as that of region 40 , but having an apparent change in intensity such that it appears that light is shining more directly thereon. A second set of multiple regions 44 is located generally along the bottom and leading edges of the graphic 20 C exhibiting an appearance of a darkened or shadowed section having little or no light shining thereon. The specific graphic 20 C shown thus creates a three-dimensional appearing image by creating the illusion of a light source placed above the graphic 20 C and creating highlights and shadows, indicating that the image has a certain depth or thickness.
[0041] The three-dimensional appearing graphic 20 C is formed through a printing process devoid of black ink. Use of black ink would impair the readability of any text the graphic 20 C might overlay. Thus, for example, in producing the three-dimensional appearing graphic, and particularly such a graphic having a fluorescent appearance, the graphic 20 C may be printed with a predetermined combination of red, blue and yellow fluorescent inks. The proper combination (i.e. a predetermined ratio) of these inks in a first composition would produce the colored central area of the graphic 20 C. Another combination of the same inks, in a second composition would render a “blackened” or darkened appearance for the shadowed regions 44 and yet another combination of the same inks in a third composition would render a proper color for lightened regions 42 to render the three-dimensional appearance of the graphic. Each of the different ink compositions are formulated so as to not impede the readability of any underlying text to which a segment 18 might be adhered.
[0042] Two dimensional graphics 20 may also be printed by combining red, blue and yellow fluorescent inks in a predetermined ratio to render a desired color with desired visual qualities. It is noted that conventional printing processes utilize a combination of cyan, magenta, yellow and black (c/m/y/k) to render a desired color. The use of red, blue and yellow with an absence of black is a departure from conventional printing processes. The printing process utilized described herein renders a bright and viewable image on a transparent film which allows application of the image to printed text without visual degradation of the text to a reader.
[0043] It is further noted that the graphic 20 C shown in FIG. 5 includes a plurality of curved edges 46 which combine to render a graphic which is without a perceived orientation. The portrayal of the graphic 20 C without a perceived orientation may provide a certain efficiency in that users of the highlighting implement 10 will not be distracted by trying to “align” the segment 18 and corresponding graphic 20 C with any particular portion of publication, such as, for example, a line of text contained therein.
[0044] While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
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A publication highlighting implement and method for making the same. The implement includes a plurality of film segments which are transparent upon application to a publication containing textual material. A graphic is printed on each segment for highlighting the textual material which the graphic is placed over. The graphic may be printed in fluorescent ink so as to increase the visibility and noticeability of the segment thus drawing attention to the underlying textual material. Additionally, the graphic may be printed to simulate a three-dimensional image or object causing the marked section to further stand out. The plurality of film segments may be arranged on a sheet of backing which is configured for use as a bookmark which may further contain advertising material thereon. Each segment may include a scalloped edge for increased ease of removal from the original backing as well as from the publication to which it is adhered.
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FIELD OF THE INVENTION
This invention relates to material level sensors, and more specifically to resistive fluent material level sensors.
BACKGROUND OF THE INVENTION
This invention relates to a unique sensing device which is known commercially and described in the literature under the trademark "Metritape" sensor, and which is the subject of several U.S. patents, including U.S. Pat. Nos. 3,511,090; 3,583,221; and 3,792,407.
The Metritape sensor comprises an elongated metallic base strip having electrical insulation on the edges and back of the strip to define an uninsulated channel along the length of the base strip, and a resistance wire or ribbon helically wound around the insulated base strip, with the helical turns bridging the insulated edge portions being spaced from the underlying uninsulated channel of the base strip. This sensor structure is enclosed within a continuous polymeric or other protective sleeve to provide a clean and dry inner chamber for the sensor. The sensor is disposed within a tank or vessel containing the liquid or fluent material, the level of which is to be monitored. The pressure of the material surrounding the immersed sensor causes the deflection of the helical turns in the immersed portion of the sensor into engagement and electrical contact with the underlying base strip, such that an electrical resistance proportional to material level is provided.
Applications for this elongated resistive sensor have ranged from the gauging of deep oil and ballast tanks on ocean-going supertankers, to land-based tanks in which turbulent and agitated slurries are held, to more quiescent tankage in which petroleum and chemical products are stored. Within such application environments, the elongated sensor strip may be subjected to shock, vibration, sudden impacts, and scraping and tearing forces which result from contact of the sensor with surrounding structure. Furthermore, the pipe, channel, tank or sump in which the sensor is housed may have sharp edges, corners, threads, welds improperly made or inadequately ground, or other structural protrusions against which the sensor may strike or chafe.
It is, furthermore, desirable that the outer sheath of the elongated resistive sensor be impervious and resistant to chemicals, solvents, slurries and suspensions in which it is immersed. It is also required that the sensor outer envelope be compliant and responsive to external material pressures so that the air/liquid interface between the material and the void space above the material can be precisely and repeatedly located by the sensor.
To achieve this combination of requirements, which include sensitivity, ruggedness and resistance to corrosion, a polymeric material such as Teflon fluorocarbon, or an olefin such as polyethylene or polypropylene, may be employed as the outer jacket envelope. Such polymers, while having excellent chemical properties, are susceptible to wear, particularly when they are brought into abrasive contact with an angular steel structure. Under severe conditions of use, it may be necessary, assuming inadequate protection is provided, to replace the sensing device at periodic intervals, thus raising the cost for such installation in terms of both replacement parts and the labor required to perform the replacement.
Conditions of usage can be particularly severe when these sensing devices are used on board ocean-going vessels which may encounter severe wave and mechanical-motion conditions in open sea. Because such conditions may occur when the tanks are empty of product, there will then be no material present to provide viscous damping and cushioning of the sensor from the interior of a close-fitting steel pipe in which it may be contained.
Several techniques have been employed to provide protection for elongated resistive sensors during their years of varying usage. The sensors have been mounted in close-fitting, elastomeric tubes, or hoses, which have soft, non-metallic interior walls, this being a structure which may be employed when elongated resistive sensors are suspended down deep observation wells.
A more common protective means has been C-shaped channel, extruded in a configuration that captures the edges and the back of the sensor, but leaves the front face open for direct access and compression by surrounding fluent material. The resulting channel or bumper strip, provides protection to the sensor edges and back, but is difficult to clean and is expensive to extrude in the most corrosion resistant of polymer materials, such as Teflon fluorocarbon polymer.
The subject invention represents a means for achieving sensor edge protection by using highly qualified materials in forms that are readily available from commercial sources, making it unnecessary to develop specialized extruding and shaping dies, and other such costly tooling, made exclusively for this particular application.
Accordingly, it is an object of this invention to create a material level-sensing device which is highly responsive to the actuation pressures it must receive, and yet is protected against adverse damaging contact and abrasion.
Another object is to achieve such properties, using protective means that are readily available in forms that require only simple modification for their use.
A further object is to employ means that are available in a wide range of advantageous materials, in a selection of sizes and configurations, and in long unspliced lengths, resulting in application suitability and in minimum material waste.
Another object is to achieve a means for protecting the edges of a precision elongated sensor structure, having such shape as to cause the sensitive faces of the structure to stand away from potentially damaging surface and edges and thereby to reduce the potential for wear and damage.
Yet another object is to have protective means available in standardized form and in such dimensions that, when added to the underlying product, the overall dimensions are within the size of available access openings, allowing the enhanced structure to be used in both existing and future installations.
An additional object is to acquire edge protection materials having both shape and Physical properties that make them easy to modify for their application and which, when applied to the underlying product, do not distort it, damage it or otherwise interfere with its full and proper functioning.
Yet another object is to provide edge-protective means in such form and flexibility that it can be progressively attached to the underlying structure by simple hand tool, both in the factory and in the field, and at a pace that makes this enhancement economically attractive.
Another objective herein is to apply edge protection to an elongated material-level transducer such that the combined and assembled structure can be easily coiled for storage, packing and shipment, and such that coiling causes minimal relative motion and wear between the protective elements and the underlying sensor itself.
Another objective of this invention is to provide a protective means which has minimal interior volume for entrapment and retention of materials, for use in food and other applications where the retention and carryover of gauged material must be minimal.
Yet another object of this invention is to achieve a friction engagement force between the add-on reinforcement and the outer envelope of the transducer itself that is sufficient to retain the protective elements in place throughout usage, but which still allow easy removal, and even reuse, of the protective elements when such is desirable.
SUMMARY OF THE INVENTION
In brief, the present invention utilizes elongated shapes, such as a polymeric or elastomeric extrusion, requiring simple processing and a convenient means of application in order to impart mechanical and physical protection to a sensitive elongated transducer strip. The resulting enhanced product can be installed in existing installation sites and, because of the added protection afforded, can be used in a wider range of applications then heretofore possible. The protective element is in one embodiment in the form of a small-bore tube having stable and rigid cross-section, but being easily coiled with the underlying transducer for purposes of storage and handling, when applied in the manner described. The resulting combined structure has been found to have advantageous performance properties when used in the field, and to be cost-economic, even when enhancement is derived from high performance fluorocarbon materials. The protective element need not be coilable, but for some applications can be rigid.
DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a cutaway pictorial view of a portion of an elongated resistive sensor within a polymeric sheath of the type with which the invention is employed;
FIG. 2 is a cutaway pictorial view of a prior art technique that has been used to mechanically protect the polymeric outer sheath of the sensor of FIG. 1;
FIG. 3 is a cross-sectional view of the elongated sensor embodying the invention to provide the prescribed sensor edge protection;
FIG. 4 is a cross-sectional top view, showing the sensor and protective elements within a typical installation in a stilling pipe;
FIG. 5A is a sectional view of an alternative protective element configuration;
FIG. 5B is a sectional view of another alternative protective element configuration;
FIG. 5C is a sectional view of yet another alternative protective element configuration;
FIG. 6 is a pictorial view of a fixture for the precise radial slitting of the tubing portion of the protective element in a straight line along the tubing longitudinal axis;
FIG. 7 is a pictorial view of a hand-operated tool for continuous application of a slit, tubular shaped protective element to an edge of the extruded polymeric sheath.
FIG. 8 is a cutaway sectional view of an alternative edge configuration of the polymeric sheath; and
FIG. 9 is a cutaway sectional view of another alternative polymeric sheath edge configuration.
DETAILED DESCRIPTION OF THE INVENTION
The elongated resistive material level sensor with which the invention is employed is sold commercially and is known as a "Metritape" sensor, shown in FIG. 1. Referring to FIG. 1, there is shown an inner sensing element 1 having electrical insulation 2 on the edges and back, this serving to space a helical resistance winding 3 away from the conducting metallic base strip of inner sensor 1. A continuous polymeric sheath or boot 4, commonly of thin Teflon fluorocarbon film, is extruded to provide a clean and dry inner chamber for the sensing element, and in the illustrated embodiment has protective beads 5 on both outer edges. The polymeric boot 4 has outboard flanges 4a that provide edge protection, but this is limited because thickness of the polymeric sheath must be kept thin (nominally 0.010 inch, each face) for the element to be appropriately sensitive to actuation pressure of surrounding material, usually liquid or slurry. As formed, the sheath 4 provides little or no protection to the top and bottom sensor faces, and it is these surfaces that are commonly abraided or penetrated by a rough steel edge, a burr, scale buildup, or projecting slag of a poorly welded pipe joint through which the sensor passes.
To protect the vulnerable polymeric sheath, which must maintain absolute tightness below the liquid surface, elongated resistive sensors are sometimes contained within flexible plastic tubes, or housed within stilling pipes which are themselves made of a plastic material that is less damaging to the thin sensor sheath. A construction long used is shown in FIG. 2. Here the inner sensor element 1 is shown contained within a polymeric sheath or boot 6, the side-flanges of which are captured by a semi-rigid plastic element 7, such as chlorinated vinyl (CPVC), to provide mechanical protection on the side edges and back surface. The polymeric boot 6 and the plastic channel 7 are sized to pass through a standard 11/2" pipe nipple having a nominal internal diameter of 1.6".
The protective channel of FIG. 2 has been widely used, but only in materials to which chlorinated vinyl is chemically resistant, or at temperatures below 70° C. (150° F.), the upper operating limit of the channel material. Such a protective channel 7 has not yet been extruded in a superior thermoplastic material, such as FEP Teflon, because of economic restraints. The cost of the more chemically and temperature resistant material, and of the more demanding extrusion process, would result in prohibitive expense for a majority of the gauging applications.
The channel structure of FIG. 2 also entraps materials at the back of the sensor, between the boot 6 and the inside of the surrounding reinforcement channel 7. This may cause materials held in a tank earlier to be carried over to the next product being stored, causing contamination of same, and sometimes producing dangerous intermixing of chemicals. The protective channel, as shown, would thus not be suitable for use in many chemical applications, or in food and dairy products where cleanliness is Paramount and the breeding of bacteria must be prevented.
A structure in accordance with the invention that entraps less material and is more open to flushing action is shown in an embodiment of the invention in FIG. 3. Here, in cross-sectional view, the elongated resistive sensor 1 is enclosed within the sheath 4, with the side flanges 4a terminated with small beads 5 on both edges. Two protective elements in the form of small-bore tubes 8 and 9, such as extruded of polymer or elastomer, are shown attached to the described sensor structure. Each tube 8 and 9 is slit radially through one side, and the tube applied so as to capture the small bead 5 within its internal diameter, thus securing the tubing as a protective side-rail. The tubing 8 and 9 can be of any suitable wall thickness. In practice both edge-protective tubings are preferably identical so that the sensing element between them would not be distorted by any differential forces, particularly during coiling and uncoiling of long lengths of the structure during storage and transportation. The tubular elements 8 and 9 preferably have an inner diameter or configuration approximately the same as the outer diameter or configuration of the beads 5 to minimize the space therebetween in which debris can collect.
The small-bore tubings 8 and 9 can be of standard tube stock which is commercially available in the local stocks of industrial distributors, and in a wide range of materials, sizes, wall thicknesses, finishes, colors and rigidities. Such tubing is commonly used to transport liquids and to transmit pneumatic or hydraulic pressure and, by its widespread usage for gas and liquid transport, is readily available at relatively low cost. For the invention, superior chemical properties, and usage at both higher and lower temperatures, is permitted at much lower material cost by use of commercially available tubing, than could be obtained through use of custom extrusions which would be prepared only for this singular use. Custom extrusions are contemplated by the invention for enhanced performance and are shown in exemplary embodiments below.
It can be seen from FIG. 3 that the protective elements 8 and 9 extend outward from the front and back faces of Teflon sheath 4 and thus tend to fend these vulnerable surfaces away from metallic edges, and particular from the internal diameters of pipes, where the structure advantageously forms a chord against the curved internal surface, further holding the thin-wall sheath away from potential puncture or abrasion.
It can also be seen from FIG. 3 that there can be very little entrapment of material by the protective elements, as the tubing provides minimal internal space into which residue might accumulate. The structure of the invention represents a significant advance over the past practice illustrated in FIG. 2. If the elements 8 and 9 are of fluorocarbon material, such as FEP or TFE Teflon, the operating temperature range of the resultant structure is greater than previously shown, allowing the use of hot water, or even mild steam for cleaning and sterilizing the elongated sensor, as may be required for certain critical applications.
Referring to FIG. 4, the sensor is shown in a typical installation in a stilling pipe 10. The dotted circle 11 represents a pipe nipple through which the elongated sensor is commonly installed. The inner dimension of this pipe nipple imposes a restraint on the width of sensors that can be easily lowered into place. The pipe 10 is representative of the size of the stilling pipe that is commonly used as a site for the elongated resistive sensor. This larger size is desirable to prevent wax or other contaminants from building up within the stilling pipe interior and thereby impeding rapid and accurate actuation of the resistive level sensor. The larger diameter also means, however, that the suspended sensor is free to move about, and abraid against, the pipe internal diameter, and such action is particularly prevalent when these sensors are used on ships at sea, and often with no liquids present in the tank to provide a desirable viscous damping effect. The side guards of the invention prevent or substantially minimize the opportunities for such damage.
The protective elements can be formed in a variety of shapes in addition to the tubular shape described above. As shown in FIG. 5A, the element 12 has oppositely extending vanes 13 and 14. This shape can be readily extruded from a suitable plastic material to suit the particular operating requirements. This shape can be sized to fit easily within the pipe nipple 11, and provides extensions 13 and 14 that further guard the front and back surfaces of the thin-wall sensor boot. The slit 15 in the tubular portion can be extruded in place, or can be formed by slitting as described. An alternative shape is shown in FIG. 5B wherein the extrusion has lip portions 16 which extend inward to provide a more extended engagement with the sensor boot. This version also includes inwardly extending thin vanes 17 which are flexible to deflect during coiling of the sensor and attached protective elements. Another shape is shown in FIG. 5C wherein thin flexible vanes 18 extend outward from tubular portion 19, and which are sufficiently flexible to deform during insertion through the pipe nipple and then spring outward to the shape illustrated to provide added protection against contact with the inner surface of the stilling pipe in which the sensor is installed. These flexible vanes can also flex during coiling of the sensor.
The shapes shown are for purposes of illustration only; there can be other configurations that fall within the scope of this invention to provide the intended protection of the sensor. The protective elements, for those versions which are coilable, should have a coiling axis which is substantially the same as that of the sensor to permit coiling and uncoiling without damage or strain to the sensor or its components.
The protective elements need not be coilable, but may be of rigid or substantially rigid construction, such as for shorter lengths of sensor. The rigid elements can be made of stiff plastic, metal or other materials having the requisite characteristics for sensor protection. The rigid elements typically can include the attachment groove for acceptance of the sensor.
An important aspect of the subject invention is the formation of an attachment seam or slit, such that the protective element will engage the polymeric boot firmly, but without damage, and which is straight and radial so as not to distort the critical edges of the sensor boot, nor cause cusps or undulations therein.
An embodiment of a slitting tool for the formation of such seam is shown in FIG. 6. Here a 90° V-channel 20 of rigid metal, such as steel or aluminum, is machined to form a thin slot 21 at the channel root 27. A clamp 24 with threaded fasteners, holds a replaceable knife blade 22, such that the cutting edge 23 of the blade faces downward toward the channel root 27 and forms an acute angle therewith. Also at the channel root, and in the same plane of the knife blade 22 is a thin metallic vane 25 that extends for a distance of several inches along the root of the channel.
In operation, tubing or other shape to be slit is introduced at the left in the direction of arrow 26. The sharp point of the blade enters the tubing internal diameter, and its cutting edge 23 first engages the tubing wall, by its raked angle, driving the tubing toward the channel root 27, which serves as an anvil against which a clean cutting action is performed. The slit tubing then advances to engage the vane 25 within the slot just cut, and the tubing is thereby held in a straight orientation as it proceeds in the direction of arrow 26. To further insure such straight cutting action the tubing, before it enters the cutting station, should be relaxed and made free of kinks and twists, paying directly and straightly from a reel, preferably of large diameter, on which the stock was originally coiled at the time of extrusion. Since it is adjustably positioned, the cutting blade 22 can be moved and angled to present a fresh cutting edge at the point of tubing engagement, and can be changed easily to a fresh blade when required.
To install the slit tubing, or other such side-rail shape, to the delicate edges of the sensor, a hand tool such as shown in FIG. 7 may be employed. Here, a plastic tubing 33 having a slit 34 oriented to the top, enters the tubular handle 30 in the direction 35. The tubing emerges into the cutout opening 31 and engages the separating finger 32. This finger may be wedge shaped to cause easy initial opening of slit 34, and is given sufficient width to open the slit adequately to pass over the bead 5 or other edge of the sensor boot. It has been found, by use of such tool, that protective elements can be flowed onto sensor edges in a smooth and continuous manner without damage to the sensor edges.
The sensor edges to which the protective elements are attached can be other than of the beaded configuration shown and described above. An alternative sensor edge construction is shown in FIG. 8 wherein the sheath 40 is formed of two strips of Teflon or other film material, each having a flared end 42 and heat sealed at position 44 to provide an enclosed inner space for the sensor strip 46. The flared edge portions 42 provide an enlarged side edge for retention of the protective element, in similar manner to the bead, as in the above embodiment. A further edge configuration for the sensor sheath is shown in FIG. 9 wherein the sheath 50 is again formed by two strips of Teflon or other film material heat sealed along the side edges, the side edges being embossed to form opposing grooves 52. The embossing can be accomplished by the heat sealing tool and can be separately provided by appropriate tooling. The embossed grooves 52 are sized and configured to accommodate and retain respective edges of the slit tubular portion of the protective element, thereby to retain the element on the side edge of the sensor.
The structure shown and described in this specification is illustrative of the forms which the subject invention may take. Other configurations incorporating similar principles and practices are deemed to fall within the spirit of this invention. Moreover, the invention is equally applicable to Metritape and other strip type sensors used for other than level sensing, such as for temperature sensing. Accordingly, the invention is not to be limited except as indicated in the appended claims.
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A distributed resistance material level sensor which is sensitive to actuation pressure of the material in which the sensor is immersed, and ruggedized to provide protection of the sensor by forces encountered during handling and during use. The sensor includes an elongated strip having sensitive front and back surfaces and respective insensitive edges extending along the length of the sensor. An elongated protective element is provided on each edge of the sensor, the element being retained on a respective insensitive edge and having a cross-sectional extent to provide mechanical contact and abrasion protection.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Section 371 National Stage application of International Application No. PCT/KR2012/005642, filed Jul. 16, 2012 and published, not in English, as WO2013/012224 on Jan. 24, 2013.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to a structure for reducing thermal displacement of a machine tool structure, and more particularly, to a structure for reducing thermal displacement of a machine tool structure capable of reducing thermal displacement of a structure in order to prevent processing precision from deteriorating due to deformation of a fixed structure by heat generated at a part where the fixed structure and a movable structure perform frictional motion together with each other.
BACKGROUND OF THE DISCLOSURE
[0003] In general, a machine tool is configured by a combination of various constituent elements such a bed frame, a column frame, a cross frame, a table unit, a turret unit, a transfer table unit, a spindle, a sub-spindle, a tailstock, and the like.
[0004] Meanwhile, a structure of the machine tool may be separated into a fixed structure and a movable structure, the movable structure is installed on the fixed structure, and the movable structure moves while performing relative motion with respect to the fixed structure.
[0005] The fixed structure may be the bed frame of the machine tool, and the movable structure may be the transfer table unit or the column frame of the machine tool.
[0006] In addition, because another movable structure may be moved by being installed on the movable structure, a particular movable structure may be understood as a fixed structure, and for example, the turret unit may be installed on the transfer table unit, and in this case, the transfer table unit may be understood as the fixed structure, and the turret unit may be understood as the movable structure.
[0007] As described above, heat due to friction is generated at the part where the fixed structure and the movable structure come in close contact with each other when the fixed structure and the movable structure move together with each other, and the heat causes thermal deformation of the fixed structure or the movable structure.
[0008] In addition, because a relative position of the movable structure with respect to the fixed structure is varied when processing of a work piece proceeds, a position at which heat is generated may be varied.
[0009] Particularly, temperature differences of the structure occur between parts to which heat is applied and parts to which heat is not applied, and because amounts of displacement of expanded parts are different from each other due to the temperature differences, distortion of the structure occur.
[0010] This thermal deformation causes problems in that processing precision of the work piece deteriorates, and further, processing quality of the work piece is lowered.
[0011] As technologies contrived in order to cope with the problems due to thermal displacement, the following Patent Literatures 1, 2, and 3 have been disclosed.
[0012] Patent Literature 1 relates to a cooling apparatus for a machine tool structure capable of reducing an error due to heat generated in a transfer system of the machine tool, which suppress heat, which is generated inevitably, by forming a cooling flow path in a ball screw shaft of the transfer system for transferring tools as well as a cooling flow path formed to prevent thermal deformation of a ball screw shaft of a spindle system.
[0013] Meanwhile, in Patent Literature 1, the respective cooling flow paths are connected to an inlet and an outlet of a provided cooler so as to be able to be circulated, and a temperature controller is included in the cooler so as to compare a temperature of discharged oil with a temperature of the atmosphere, and cool oil flowing into the inlet.
[0014] However, in the technology disclosed in Patent Literature 1, because a large number of peripheral devices such as an oil tank, a condenser, an evaporator, an expansion valve, various pipes, and the like are required in order to cool and circulate oil, a configuration of the cooling apparatus is complicated, and a number of precautions are required to perform maintenance management thereof.
[0015] Patent Literature 2 relates to a cooling apparatus for a machine tool that cools heat generated at a spindle head by forming an oil space between an outer wall and an inner wall of the spindle head, and supplying and circulating cooling oil from an oil tank to an oil space formed in the spindle head through a cooling medium line.
[0016] However, in the technology disclosed in Patent Literature 2, there are problems in that because a large number of peripheral devices are required similarly to Patent Literature 1 in order to circulate cooling oil, a number of precautions are required to perform maintenance management thereof, and because a cooling operation is limited to the spindle head, heat generated at other structures such as a bed frame of the machine tool may not be cooled.
[0017] In Patent Literature 3, a temperature sensor is provided at a part where heat generation is estimated, an amount of thermal displacement is detected based on information obtained from the temperature sensor, and an amount of relative movement with respect to the respective shafts is corrected by converting the displacement amount.
[0018] However, in the technology disclosed in Patent Literature 3, the amounts of movements of the respective shafts are corrected with numbers by calculating information provided by a plurality of temperature sensors using a S/W, but it is difficult to accurately estimate a direction in which a structure is distorted or deformed because environment (temperature, humidity, or the like) where the machine tool is installed and operated is varied, and processing forms for work pieces are various, there may be a case in which a result value, which is theoretically obtained, and a correcting value, which needs to be actually applied, are different from each other, and in this case, there is a problem in that it is difficult to perform precise processing.
CITATION LIST
Patent Literature
[0000]
(Patent Literature 1) Korean Patent Application Laid-Open No. 10-2004-0100135 (Dec. 2, 2004)
(Patent Literature 2) Korean Patent No. 10-1995-003042 (Mar. 30, 1995)
(Patent Literature 3) Korean Patent Application Laid-Open No. 10-2007-0118666 (Dec. 17, 2007)
[0022] The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
SUMMARY
[0023] This summary and the abstract are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. The summary and the abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter.
[0024] Accordingly, in order to resolve a technical problem, an embodiment of the present disclosure is to provide a structure for reducing thermal displacement of a machine tool structure capable of preventing a structure from being deformed and distorted by reducing a temperature deviation over the entire structure by rapidly transferring heat to other parts when a temperature of a specific part of the structure is raised.
[0025] Technical problems of the present disclosure are not limited to the technical problems described above, and technical problems that are not described will be clearly understood by a person skilled in the art from the description below.
[0026] In order to achieve the technical problem, a structure for reducing thermal displacement of a machine tool structure according to the present disclosure includes: a fixed structure 100 which is provided in the machine tool and has one side on which a guide rail 102 is formed; a movable structure 120 which is installed on the guide rail 102 , and moves; and a cooling unit 300 which allows cooling oil to be circulated in the fixed structure 100 so as to cool the fixed structure 100 , and allows temperature distribution of the fixed structure 100 to be uniform, in which the cooling unit 300 includes: a first cooling unit which is disposed in the fixed structure 100 to be adjacent to the guide rail 102 , and performs a heat exchange between heat generated at the guide rail 102 and the cooling oil; a second cooling unit which is disposed below the first cooling unit to be spaced apart from the first cooling unit on the basis of the overall configuration of the fixed structure 100 , and performs a heat exchange; and a pump unit 400 which is disposed at one side of the cooling unit 300 , and forcibly circulates the cooling oil along the first and second cooling units.
[0027] In addition, the first cooling unit may be first and third cooling flow paths 301 and 303 which are disposed to be parallel to each other on the basis of the guide rail 102 , the second cooling unit may be fifth and seventh cooling flow paths 305 and 307 which are disposed below the first and third cooling flow paths 301 and 303 to be spaced apart from the first and third cooling flow paths 301 and 303 , fourth and eighth cooling flow paths 304 and 308 may be further included which connect the first and third cooling flow paths 301 and 303 and the fifth and seventh cooling flow paths 305 and 307 , respectively, and the first and third cooling flow paths 301 and 303 and the fifth and seventh cooling flow paths 305 and 307 may be disposed in an internal space of the fixed structure 100 in the form of a ‘⊂’.
[0028] In addition, the structure may further include a second cooling flow path 302 which connects the first cooling flow path 301 and the third cooling flow path 303 ; and a sixth cooling flow path 306 which connects the fifth cooling flow path 305 and the seventh cooling flow path 307 , in which the first, second, third, fourth, fifth, sixth, seventh, and eighth cooling flow paths 301 , 302 , 303 , 304 , 305 , 306 , 307 , and 308 are disposed in the fixed structure 100 in the form of a loop so as to allow the cooling oil to be circulated.
[0029] In addition, the cooling unit 300 may include: a first loop cooling unit 310 which is disposed in the fixed structure 100 to be adjacent to the guide rail 102 , and performs a heat exchange by circulating the cooling oil in the form of a loop; and a second loop cooling unit 320 which is disposed below the guide rail 102 to be spaced apart from the guide rail 102 on the basis of the overall configuration of the fixed structure 100 , and performs a heat exchange by circulating the cooling oil in the form of a loop.
[0030] In addition, the structure may further include a third loop cooling unit 330 which is disposed between the first loop cooling unit 310 and the second loop cooling unit 320 on the basis of the overall configuration of the fixed structure 100 , and performs a heat exchange by circulating the cooling oil in the form of a loop.
[0031] In addition, the structure may further include a connecting cooling flow path 340 which is disposed to connect the first loop cooling unit 310 and the second loop cooling unit 320 to each other, and circulates the cooling oil.
[0032] In addition, the structure may further include auxiliary cooling flow paths 350 which are disposed at the first loop cooling unit 310 and the second loop cooling unit 320 , respectively, and increase an area for a heat exchange by circulating the cooling oil across the first loop cooling unit 310 and the second loop cooling unit 320 .
[0033] In addition, in order to achieve the technical problem, a structure for reducing thermal displacement of a machine tool structure according to the present disclosure includes: a fixed structure 200 which is provided in the machine tool, and has one side on which a guide rail 202 is formed; a movable structure 210 which is installed on the guide rail 202 of the fixed structure 200 , and moves; and a cooling unit 300 which is disposed at the fixed structure 200 to be adjacent to the guide rail 202 on the basis of the overall configuration of the fixed structure 200 , and allows temperature distribution of the fixed structure 200 to be uniform by performing a heat exchange between heat generated at the guide rail 202 and the cooling oil so as to cool the fixed structure 200 .
[0034] In addition, a cooling flow path of the cooling unit 300 may be disposed to pass through the guide rail 202 .
[0035] Details of other exemplary embodiments are included in the detailed description and the drawings.
[0036] In the structure for reducing thermal displacement of a machine tool structure according to the present disclosure, which is configured as described above, even though high-temperature heat is generated at an unspecified part, the heat is rapidly transferred to other parts by the cooling oil in the cooling flow path, so that the overall temperature deviation of the structure may become uniform, thereby reducing problems that the structure of the machine tool is deformed due to thermal displacement.
[0037] In addition, the system for reducing thermal displacement of a machine tool structure according to the present disclosure may use the cooling oil semipermanently after filling the cooling oil into the cooling flow path such that there is a merit in that it is convenient because separate maintenance is not required.
[0038] In addition, the system for reducing thermal displacement of a machine tool structure according to the present disclosure requires the cooling flow path through which the cooling oil is circulated, and constituent elements of the pump which forcibly circulates the cooling oil, a manufacturing process is easy, and manufacturing costs may be low in comparison with technologies known in the related art.
DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is an illustrative view for explaining a structure of a machine tool.
[0040] FIG. 2 is an illustrative view illustrating an example in which a temperature is raised at a specific part of a structure that is a first comparative example of a machine tool.
[0041] FIG. 3 is an illustrative view for explaining thermal displacement when a temperature is raised at a specific part of the structure that is the first comparative example of the machine tool.
[0042] FIGS. 4 and 5 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to first and second exemplary embodiments of the present disclosure.
[0043] FIG. 6 is a view for explaining a cooling flow path formed in a structure in the structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure.
[0044] FIG. 7 is a view for comparing and explaining temperature distribution of the structure of the first comparative example and of a structure to which the structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure is applied.
[0045] FIGS. 8 to 14 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to third to ninth exemplary embodiments of the present disclosure.
[0046] FIG. 15 is a view for explaining a structure that is a second comparative example of the machine tool.
[0047] FIGS. 16 and 17 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to tenth and eleventh exemplary embodiments of the present disclosure.
[0048] FIG. 18 is a view for explaining a structure that is a third comparative example of the machine tool.
[0049] FIGS. 19 and 20 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to a twelfth exemplary embodiment of the present disclosure.
[0050] FIGS. 21 and 22 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to a thirteenth exemplary embodiment of the present disclosure.
[0051] FIGS. 23 and 24 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to a fourteenth exemplary embodiment of the present disclosure.
DESCRIPTION OF MAIN REFERENCE NUMERALS OF DRAWINGS
[0000]
100 , 200 : Fixed structure
110 , 120 , 130 , 210 : Movable structure
102 , 202 : Guide rail
204 : First Part
206 : Second part
300 : Cooling unit
301 to 309 : First to eighth cooling flow paths
310 , 320 , 330 : First to third loop cooling units
340 : Connecting cooling flow path
350 : Auxiliary cooling flow path
400 : Pump unit
DETAILED DESCRIPTION
[0063] The advantages and characteristics of the present disclosure and methods for achieving the same will become clear from the exemplary embodiments set forth in detail below with reference to the accompanying drawings.
[0064] Like reference numerals represent like elements throughout the specification.
[0065] First, a structure of a machine tool will be described with reference to FIG. 1 .
[0066] The structure may be defined as a fixed structure 100 and movable structures 110 , 120 , and 130 , a guide rail 102 is formed on the fixed structure 100 , and the movable structure 120 is installed on the guide rail 102 .
[0067] In the description of the present disclosure, a bed frame will be described as an example of the fixed structure 100 , and a transfer table will be described as an example of the movable structure 120 .
[0068] Meanwhile, another movable structure may be installed on the movable structure 120 as a similar structure, and for example, a turret unit 130 may be installed on a transfer table (see 120 ).
[0069] In addition, a yet another movable structure may be installed on the fixed structure 100 , and for example, a constituent element such as a spindle 110 , a tailstock, a vibration absorber, or the like may be installed.
[0070] That is, a stationary structure may be understood as the fixed structure 100 , and a moving structure may be understood as the movable structure 120 , on the basis of motion forms of the fixed structure 100 and the movable structure 120 .
First Comparative Example
[0071] Thermal displacement of the fixed structure 100 of a first comparative example will be described with reference to the accompanying FIGS. 2 and 3 .
[0072] The accompanying FIG. 2 is a view illustrating temperature distribution after performing a simulation using a thermal flow analysis software, and the accompanying FIG. 3 is a view illustrating thermal deformation.
[0073] The movable structure 120 may be moved by a transfer system unit, and here, because friction occurs between the fixed structure 100 and the movable structure 120 , a temperature of a part at which friction occurs is raised relatively to temperatures of other parts.
[0074] The part at which friction occurs may be a part of the guide rail 102 that guides the movement of the movable structure 120 , and supports a load of the movable structure 120 .
[0075] Referring to FIG. 2 , it can be seen that a temperature is raised concentratedly to a part of the guide rail 102 in the fixed structure 100 .
[0076] Referring to FIG. 3 , it can be seen that heat is generated at the movable structure 120 , and a phenomenon occurs in which the fixed structure 100 that is the bed frame is distorted by the heat.
[0077] Heat may be generated concentratedly when a spindle is driven, or the transfer system unit is driven, and the generated heat is transferred to a structure such as the bed frame, the transfer table, and the like.
[0078] Therefore, the structure is deformed by variations in temperature, but because temperature distribution of the structure is not uniform when the structure is expanded, it is not possible to expect in which direction and form the structure is deformed, and therefore it is difficult to estimate in which direction and to what extent a correction is performed.
[0079] Therefore, the exemplary embodiment according to the present disclosure is to reduce thermal displacement of the structure by allowing temperature distribution to be uniform over the entire structure by rapidly transferring heat generated at a specific part of the structure to other parts.
[0080] Hereinafter, a structure for reducing thermal displacement of a machine tool structure according to first and second exemplary embodiments of the present disclosure will be described with reference to FIGS. 4 to 7 .
[0081] The accompanying FIGS. 4 and 5 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure, FIG. 6 is a side view for explaining a cooling flow path formed in a structure in the structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure, and FIG. 7 is a view for comparing and explaining temperature distribution of the structure of the first comparative example and of a structure to which the structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure is applied.
First Exemplary Embodiment
[0082] In the structure for reducing thermal displacement of a machine tool structure according to the first exemplary embodiment of the present disclosure, the guide rail 102 is formed on the fixed structure 100 , the movable structure 120 is installed on the guide rail 102 , and a cooling unit 300 is disposed in the fixed structure 100 .
[0083] The cooling unit 300 includes cooling flow paths (see 301 to 309 ) which circulate cooling oil.
[0084] In more detail, the cooling unit 300 may include first and second cooling units.
[0085] The first cooling unit is disposed in the fixed structure 100 to be adjacent to the guide rail 102 , and performs a heat exchange between heat generated at the guide rail 102 and the cooling oil.
[0086] The second cooling unit is disposed below the first cooling unit to be spaced apart from the first cooling unit on the basis of the overall configuration of the fixed structure 100 and performs a heat exchange.
[0087] A pump unit 400 is disposed at one side of the cooling unit 300 , and the pump unit 400 forcibly circulates the cooling oil along the first and second cooling units.
[0088] The cooling flow path has a configuration in which a plurality of holes is formed in a longitudinal direction of the fixed structure 100 , pipes are disposed in the holes, and the plurality of pipes is filled with the cooling oil.
[0089] That is, first and third cooling flow paths 301 and 303 are formed to be parallel to a longitudinal direction of the guide rail 102 and adjacent to the guide rail 102 , a fifth cooling flow path 305 is formed at a bottom side of the fixed structure 100 , the first cooling flow path 301 and the third cooling flow path 303 are connected to a second cooling flow path 302 , and the third cooling flow path 303 and the fifth cooling flow path 305 are connected to a fourth cooling flow path 304 .
[0090] The first cooling unit may be the first and third cooling flow paths 301 and 303 which are disposed to be parallel to each other on the basis of the guide rail 102 .
[0091] In addition, the second cooling unit may be fifth and seventh cooling flow paths 305 and 307 which are disposed below the first and third cooling flow paths 301 and 303 to be spaced apart from the first and third cooling flow paths 301 and 303 .
[0092] Meanwhile, because the first and third cooling flow paths 301 and 303 and the fifth and seventh cooling flow paths 305 and 307 may be disposed in an internal space of the fixed structure 100 in the form of a ‘⊂’, the fixed structure 100 may be configured to help uniformly distribute the cooling paths, and moreover, an effect of performing a heat exchange so as to allow temperature distribution of the fixed structure 100 to be uniform may be improved.
[0093] Meanwhile, the fifth cooling flow path 305 and the first cooling flow path 301 may be connected to a ninth cooling flow path 309 , and the ninth cooling flow path 309 may be exposed outward from the fixed structure 100 so as to be connected.
[0094] A temperature of a specific part is raised by a heat source such as heat generated from the movable structure 120 at the guide rail 102 , heat generated by pressure, or the like.
[0095] Here, when the pump unit 400 forcibly circulates the cooling oil, heat at a high-temperature part is moved to a low-temperature part such that a heat exchange is performed, and thereby, the entire heat distribution of the fixed structure 100 may become uniform.
Second Exemplary Embodiment
[0096] The structure for reducing thermal displacement of a machine tool structure according to the second exemplary embodiment of the present disclosure refers to a structure in which the structure of the cooling unit 300 of the first exemplary embodiment is changed.
[0097] As illustrated in FIG. 5 , the cooling unit 300 includes cooling flow paths (see 301 to 308 ) which allows the cooling oil to be circulated by the pump unit 400 .
[0098] In the cooling flow paths, the first and third cooling flow paths 301 and 303 are formed to be parallel to a longitudinal direction of the guide rail 102 and adjacent to the guide rail 102 , the fifth and seventh cooling flow paths 305 and 307 are formed a bottom side of the fixed structure 100 , the first cooling flow path 301 and the third cooling flow path 303 are connected to a second cooling flow path 302 , and the third cooling flow path 303 and the fifth cooling flow path 305 are connected to a fourth cooling flow path 304 .
[0099] Similarly, the fifth cooling flow path 305 and the seventh cooling flow path 307 are connected to a sixth cooling flow path 306 , and the seventh cooling flow path 307 and the first cooling flow path 301 are connected to an eighth cooling flow path 308 .
[0100] That is, the cooling flow paths of the second exemplary embodiment are circulated in the structure in a closed form.
[0101] Therefore, when a temperature is raised at a specific part of the guide rail 102 of the fixed structure 100 , the pump unit 400 forcibly circulates the cooling oil, heat at a high-temperature part is moved to a low-temperature part such that a heat exchange is performed, and thereby, the entire heat distribution of the fixed structure 100 may become uniform.
[0102] The accompanying FIG. 6 is a side view for explaining the cooling flow paths of the second exemplary embodiment.
[0103] As illustrated in FIG. 6 , in the cooling flow paths, the first and third cooling flow paths 301 and 303 are disposed at a position adjacent to the guide rail 102 , and the fifth and seventh cooling flow paths 305 and 307 are disposed below the fixed structure 100 .
[0104] Therefore, while high-temperature cooling oil is circulated, a heat exchange is performed at a lower side of the fixed structure 100 where a temperature is relatively low, and thereby, temperature distribution of the fixed structure 100 becomes uniform.
[0105] Hereinafter, an operation of the structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure will be described with reference to the accompanying FIG. 7 .
[0106] FIG. 7( a ) illustrates temperature distribution of the machine tool structure of the first comparative example in which the cooling unit 300 is not provided, FIG. 7( b ) illustrates temperature distribution of the machine tool structure according to the first exemplary embodiment, and FIG. 7( c ) illustrates temperature distribution of the machine tool structure according to the second exemplary embodiment.
[0107] As illustrated in FIG. 7 , it can be seen that the overall temperature distribution of the machine tool structure becomes uniform by rapidly cooling a temperature that is locally raised in accordance with whether or not the cooling unit 300 is provided.
[0108] Hereby, in the structure for reducing thermal displacement of a machine tool structure according to the first and second exemplary embodiments of the present disclosure, it may be confirmed that local thermal deformation of the machine tool structure is prevented such that thermal displacement may be efficiently reduced, and moreover, deformation of the structure is reduced such that a relative high-precision processing may be implemented.
Third Exemplary Embodiment
[0109] A structure for reducing thermal displacement of a machine tool structure according to a third exemplary embodiment of the present disclosure refers to a structure in which the structure of the cooling unit 300 of the first exemplary embodiment is changed.
[0110] That is, the cooling unit 300 includes a plurality of loop cooling units (see 310 and 320 ) that allows the cooling oil to be circulated in a closed circuit, and the respective loop cooling units include pump units, respectively, and may forcibly circulate the cooling oil.
[0111] As illustrated in FIG. 8 , in the third exemplary embodiment, the first loop cooling unit 310 is disposed at a side close to the guide rail of the fixed structure 100 , and the second loop cooling unit 320 is disposed at a side farther on the basis of the guide rail than the first loop cooling unit 310 .
[0112] Therefore, in the first and second loop cooling units 310 and 320 of the third exemplary embodiment, a distance of a path through which the cooling oil is circulated may be shorter in comparison with the first and second exemplary embodiments, and hereby, a heat exchange is more rapidly performed such that heat distribution may rapidly become uniform.
Fourth Exemplary Embodiment
[0113] A structure for reducing thermal displacement of a machine tool structure according to a fourth exemplary embodiment of the present disclosure refers to a structure in which the structure of the loop cooling unit of the third exemplary embodiment is changed.
[0114] As illustrated in FIG. 9 , the fourth exemplary embodiment is further provided with a third loop cooling unit 330 between the first loop cooling unit 310 and the second loop cooling unit 320 .
[0115] Hereby, high-temperature heat generated at a specific part of the fixed structure 100 may be rapidly transferred to other parts, and particularly, heat is rapidly transferred to the entire fixed structure 100 by the plurality of first, second, and third loop cooling units 310 , 320 , and 330 , and thereby heat distribution may rapidly become uniform.
Fifth Exemplary Embodiment
[0116] A structure for reducing thermal displacement of a machine tool structure according to a fifth exemplary embodiment of the present disclosure refers to a structure in which the structure of the loop cooling unit of the third exemplary embodiment is changed.
[0117] As illustrated in FIG. 10 , the fifth exemplary embodiment is further provided with a connecting cooling flow path 340 so as to connect the first loop cooling unit 310 and the second loop cooling unit 320 .
[0118] Hereby, the cooling oil in the first loop cooling unit 310 may be circulated to the second loop cooling unit 320 , high-temperature heat generated at a specific part of the fixed structure 100 may be rapidly transferred to other parts, and particularly, the cooling oil is circulated in the first and second loop cooling units 310 and 320 through the connecting cooling flow path 340 such that heat is rapidly transferred to the entire fixed structure 100 , and thereby heat distribution may rapidly become uniform.
Sixth Exemplary Embodiment
[0119] A structure for reducing thermal displacement of a machine tool structure according to a sixth exemplary embodiment of the present disclosure refers to a structure in which the structure of the loop cooling unit of the fourth exemplary embodiment is changed.
[0120] As illustrated in FIG. 11 , the sixth exemplary embodiment is further provided with the connecting cooling flow path 340 so as to connect the first loop cooling unit 310 , the second loop cooling unit 320 , and the third loop cooling unit 330 .
[0121] Hereby, the cooling oil in the first loop cooling unit 310 may be circulated to the second and third loop cooling units 320 and 330 , high-temperature heat generated at a specific part of the fixed structure 100 may be rapidly transferred to other parts, and particularly, the cooling oil is circulated in the first, second, and third loop cooling units 310 , 320 , and 330 through the connecting cooling flow path 340 such that heat is rapidly transferred to the entire fixed structure 100 , and thereby heat distribution may rapidly become uniform.
Seventh Exemplary Embodiment
[0122] A structure for reducing thermal displacement of a machine tool structure according to a seventh exemplary embodiment of the present disclosure refers to a structure in which the structure of the loop cooling unit of the third exemplary embodiment is changed.
[0123] As illustrated in FIG. 12 , the seventh exemplary embodiment is further provided with an auxiliary cooling flow path 350 in addition to the first and second loop cooling units 310 and 320 .
[0124] The auxiliary cooling flow path 350 is provided so that when the cooling oil is circulated in the first and second loop cooling units 310 and 320 , one part of the cooling oil is circulated along all of the paths of the first and second loop cooling units 310 and 320 , and the other part thereof is circulated across the first and second loop cooling units 310 and 320 .
[0125] Furthermore, the auxiliary cooling flow path 350 improves heat exchange efficiency by increasing an area for a heat exchange.
[0126] That is, in the seventh exemplary embodiment, the cooling oil may be more rapidly circulated, and hereby heat at a high-temperature part is rapidly transferred to a low-temperature part such that temperature distribution of the structure may become uniform.
Eighth Exemplary Embodiment
[0127] A structure for reducing thermal displacement of a machine tool structure according to an eighth exemplary embodiment of the present disclosure refers to a structure in which the structure of the loop cooling unit of the seventh exemplary embodiment is changed.
[0128] As illustrated in FIG. 13 , the eighth exemplary embodiment is configured by putting auxiliary cooling flow paths 350 across each other in the form of an X in the first and second loop cooling units 310 and 320 such that the cooling oil may be rapidly circulated.
[0129] The auxiliary cooling flow path 350 is provided so that when the cooling oil is circulated in the first and second loop cooling units 310 and 320 , one part of the cooling oil is circulated along all of the paths of the first and second loop cooling units 310 and 320 , and the other part thereof is circulated across the first and second loop cooling units 310 and 320 .
[0130] That is, in the eighth exemplary embodiment, the cooling oil may be more rapidly circulated, and hereby heat at a high-temperature part is rapidly transferred to a low-temperature part such that temperature distribution of the structure may become uniform.
Ninth Exemplary Embodiment
[0131] A structure for reducing thermal displacement of a machine tool structure according to a ninth exemplary embodiment of the present disclosure refers to a structure in which the structure of the loop cooling unit of the eighth exemplary embodiment is changed.
[0132] As illustrated in FIG. 14 , the ninth exemplary embodiment is further provided with the third loop cooling unit 330 in addition to the first and second loop cooling units 310 and 320 , and includes the auxiliary cooling flow paths 350 , which is put across each other in the form of an X, at the respective first, second, and third loop cooling units 310 , 320 , and 330 such that the cooling oil may be rapidly circulated in the respective loop cooling units.
[0133] The auxiliary cooling flow path 350 is provided so that when the cooling oil is circulated in the first, second, and third loop cooling units 310 , 320 , and 330 , one part of the cooling oil is circulated along all of the paths of the first, second, and third loop cooling units 310 , 320 , and 330 , and the other part thereof is circulated across the first, second, and third loop cooling units 310 , 320 , and 330 .
[0134] That is, in the ninth exemplary embodiment, the cooling oil may be more rapidly circulated, and hereby heat at a high-temperature part is rapidly transferred to a low-temperature part such that temperature distribution of the structure may become uniform.
Second Comparative Example
[0135] The accompanying FIG. 15 is a view for explaining a structure that is a second comparative example of the machine tool.
[0136] As illustrated in FIG. 15 , a structure may be disposed in a vertical direction or in an inclined direction in accordance with a disposition form thereof.
[0137] In more detail, the guide rail 202 may be formed on one side of the fixed structure 200 in a vertical direction or in an inclined direction, and the movable structure 210 is installed on the guide rail 202 so as to be moved by a transfer system unit.
[0138] In the machine tool, heat is generated due to various reasons such as heat generation at various motors, heat generation at bearings, heat generation at ball screws, heat generation at gear boxes, heat generation in a process of cutting work pieces, heat generation at hydraulic units, or the like, and the generated heat is transferred to the structure.
[0139] The generated heat causes a problem of thermal deformation in which the structure is distorted by locally raising a temperature at a specific part of the structure.
[0140] Particularly, in the structure, a phenomenon occurs in which a temperature at the guide rail 202 is locally raised, compressive stress and tensile stress may be simultaneously applied to the guide rail 202 when the fixed structure 200 and the movable structure 210 perform motion together with each other, and heat may be generated due to friction when the movable structure 210 is moved.
[0141] That is, as illustrated in FIG. 15 , in the second comparative example, a large amount of temperature deviation occurs at the guide rail 202 part and a rear part of the fixed structure 200 , and this temperature deviation causes a problem of increasing thermal displacement of the structure.
Tenth Exemplary Embodiment
[0142] In a structure for reducing thermal displacement of a machine tool structure according to a tenth exemplary embodiment of the present disclosure, the cooling unit 300 is disposed on the guide rail 202 of the fixed structure 200 .
[0143] In more detail, the cooling unit 300 allows the cooling oil to be circulated in the fixed structure 200 .
[0144] When a simulation is performed using a thermal flow analysis software, it can be seen that a temperature is relatively lowered in comparison with the second comparative example, and it can be seen that temperature distribution becomes uniform with respect to the entire guide rail 202 .
[0145] That is, as temperatures of the guide rail 202 become uniform, thermal displacement is reduced, and thereby a high-precision processing may be implemented.
Eleventh Exemplary Embodiment
[0146] A structure for reducing thermal displacement of a machine tool structure according to an eleventh exemplary embodiment of the present disclosure is implemented by changing the disposition of the cooling unit 300 of the tenth exemplary embodiment.
[0147] In more detail, high-temperature heat is rapidly transferred to other parts of the structure by disposing the cooling unit 300 on the guide rail 202 that becomes a heat source.
[0148] When a simulation is performed using the thermal flow analysis software, it can be seen that temperature distribution becomes more uniform with respect to the entire guide rail 202 in comparison with the tenth exemplary embodiment.
[0149] That is, as temperatures of the guide rail 202 become uniform, thermal displacement is further reduced, and thereby a high-precision processing may be implemented.
Third Comparative Example
[0150] FIG. 18 is a view for explaining a structure that is a third comparative example of the machine tool.
[0151] The structure (fixed structure, see 200 ) of the third comparative example refers to a structure in a hollow form of which inside is vacant, and has a form having one side on which the guide rail 202 is formed.
[0152] When the fixed structure 200 is described in more detail, the guide rail 202 is provided in the form of protrusion, and on the basis of the guide rail 202 , the fixed structure 200 may be separated into a first part 204 , which is close to the guide rail 202 , and a second part 206 , which is far from the guide rail 202 .
[0153] When a simulation is performed using the thermal flow analysis software, it can be seen that a temperature difference greatly occurs between the guide rail 202 (source where heat is generated) and a rear side (the second part 206 ) of the fixed structure 200 .
[0154] In the fixed structure 200 , a maximum temperature at a specific part was 21.482° C., and a maximum temperature deviation was indicated as 1.332° C.
[0155] That is, this temperature deviation causes a problem of increasing thermal displacement of the fixed structure 200 .
Twelfth Exemplary Embodiment
[0156] The accompanying FIGS. 19 and 20 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to a twelfth exemplary embodiment of the present disclosure.
[0157] The twelfth exemplary embodiment is provided with the cooling unit 300 in addition to the structure of the third comparative example.
[0158] In more detail, the cooling unit 300 is configured so that the cooling oil may be circulated therein.
[0159] When seeing the entire shape of the fixed structure 200 , the cooling unit 300 is disposed at the first part 204 that is a position close to the guide rail 202 .
[0160] When a simulation of the twelfth exemplary embodiment is performed using the thermal flow analysis software, there was an overall cooling effect, a maximum temperature was 21.025° C., and a maximum deviation was indicated as 0.946° C.
[0161] That is, it can be seen that the twelfth exemplary embodiment may reduce a temperature deviation in comparison with the third comparative example, and thereby thermal displacement of the fixed structure 200 may be reduced.
Thirteenth Exemplary Embodiment
[0162] FIGS. 21 and 22 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to a thirteenth exemplary embodiment of the present disclosure.
[0163] The thirteenth exemplary embodiment is provided with the cooling unit 300 in addition to the structure of the third comparative example so that the cooling oil may be circulated.
[0164] In more detail, with respect to a position at which the cooling unit 300 is disposed, when seeing the entire shape of the fixed structure 200 , the cooling unit 300 is disposed at the guide rail 202 and at the second part 206 which is far from the guide rail 202 .
[0165] When a simulation of the thirteenth exemplary embodiment is performed using the thermal flow analysis software, there was an overall cooling effect, a maximum temperature was 20.589° C., and a maximum deviation was indicated as 0.567° C.
[0166] That is, it can be seen that the thirteenth exemplary embodiment may further reduce a temperature deviation in comparison with the twelfth exemplary embodiment, and thereby thermal displacement of the fixed structure 200 may be further reduced.
Fourteenth Exemplary Embodiment
[0167] FIGS. 23 and 24 are views for explaining a structure for reducing thermal displacement of a machine tool structure according to a fourteenth exemplary embodiment of the present disclosure.
[0168] The fourteenth exemplary embodiment is provided with the cooling unit 300 in addition to the structure of the third comparative example so that the cooling oil may be circulated.
[0169] In more detail, with respect to a position at which the cooling unit 300 is disposed, when seeing the entire shape of the fixed structure 200 , the cooling unit 300 is disposed at the guide rail 202 .
[0170] When a simulation of the fourteenth exemplary embodiment is performed using the thermal flow analysis software, there was an overall cooling effect, a maximum temperature was 20.589° C., and a maximum deviation was indicated as 0.533° C.
[0171] That is, it can be seen that the fourteenth exemplary embodiment may further reduce a temperature deviation in comparison with the thirteenth exemplary embodiment, and thereby thermal displacement of the fixed structure 200 may be further reduced.
[0172] As described above, the structure for reducing thermal displacement of a machine tool structure according to the exemplary embodiments of the present disclosure may allow the overall temperature distribution of the structure to become uniform by rapidly transferring high-temperature heat of a heat source to a part of which a temperature is relatively low, and thereby the structure may reduce thermal displacement with respect to thermal stress.
[0173] In addition, the structure for reducing thermal displacement of a machine tool structure according to the exemplary embodiments of the present disclosure may implement ultra-high-precision processing by reducing thermal displacement.
[0174] On the other hand, a system for reducing thermal displacement of a machine tool structure according to the exemplary embodiments of the present disclosure is used at a temperature greatly lower than an evaporation temperature of the cooling oil even when heat is generated such that evaporation or loss of the cooling oil barely occurs, and therefore the cooling oil may be used semipermanently.
[0175] In addition, in the system for reducing thermal displacement of a machine tool structure according to the exemplary embodiments of the present disclosure, external impurities do not flow into the cooling oil, and the coolant oil may perform an action of a coolant for a heat exchange because debris does not affect the circulation even though minute debris flows into the cooling oil, and thereby a filtering device like the related art may not be provided.
[0176] In addition, since the system for reducing thermal displacement of a machine tool structure according to the exemplary embodiments of the present disclosure simply circulates the cooling oil when circulating the cooling oil, the pump unit 400 may not be compulsorily driven, and thereby a lifespan of the pump unit 400 is not extremely shortened.
[0177] That is, in the system for reducing thermal displacement of a machine tool structure according to the exemplary embodiments of the present disclosure, a large number of subordinate equipment like the related art is not required such that there is an effect of reducing costs, and separate costs and labor are not required to perform maintenance.
[0178] While the exemplary embodiments of the present disclosure have been described with reference to the accompanying drawings, those skilled in the art will appreciate that the present disclosure can be implemented in other detailed embodiments, without departing from the technical spirit and essential features of the disclosure.
[0179] Therefore, it should be understood that the above-described exemplary embodiments are only illustrative in all aspects, not restrictive. The scope of the present disclosure should be defined by the accompanying claims rather than the detailed description. Various modifications, additions, and substitutions derived from the meaning and scope of the accompanying claims and equivalent concept thereof should be interpreted as being included in the scope of the present disclosure.
[0180] The structure for reducing thermal displacement of a machine tool structure according to the present disclosure may be used to implement a high-precision processing by rapidly transferring heat to other parts when a temperature is raised at a specific part of the structure of the machine tool, and by allowing the overall temperature distribution of the structure to become uniform so as to reduce thermal displacement of the structure.
[0181] Although the present disclosure has been described with reference to exemplary and preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the disclosure.
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The present disclosure relates to a structure for reducing thermal displacement of a machine tool structure, and more particularly, to a structure for reducing thermal displacement of a machine tool structure capable of reducing thermal displacement of a structure in order to prevent processing precision from deteriorating due to deformation of a fixed structure by heat generated at a part where the fixed structure and a movable structure perform frictional motion together with each other. Accordingly, in order to resolve a technical problem, an object of the present invention is to provide a structure for reducing thermal displacement of a machine tool structure capable of preventing a structure from being deformed and distorted by reducing a temperature deviation over the entire structure by rapidly transferring heat to other parts when a temperature of a specific part of the structure is raised.
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FIELD OF THE INVENTION
This invention relates to strength testing of ceramic honeycomb structures. More particularly, the invention relates to apparatus and methods for testing the compressive strength of such structures.
BACKGROUND OF THE INVENTION
Compressive strength is an important feature of thin-walled ceramic honeycomb structures, which are used in the manufacture catalyst supports. Honeycomb structures have a webbed cellular or channeled core structure surrounded in most cases by a smooth integral outer skin layer. The manufacture of structures by extrusion to form cellular ceramic honeycombs of cordierite composition and very low thermal expansion from plasticized mixtures of ceramic batch materials is described in U.S. Pat. Nos. 3,790,654 and 3,885,977. Such honeycombs remain in widespread commercial use as catalyst supports for emissions control applications such as automotive exhaust treatment systems.
One way of improving the exhaust conversion efficiency of catalyst supports is to produce honeycomb products with thinner webs. Currently, the assignee of the present patent application manufactures catalyst supports having web thicknesses in the range of two mils. Thinner webbed structures result in parts that have reduced compressive strength. In the manufacture of exhaust system components, catalyst supports are typically surrounded with a housing comprised of a metal layer. The process for surrounding the parts with a metal layer is known in the art as “canning”. The canning process used to place a metal housing around ceramic catalyst supports exerts compressive stresses on the catalyst support. Manufacturers of catalyst supports must be able to provide products that are able to withstand compressive forces encountered during canning processes.
Various apparatus exist for testing compressive strength of ceramic honeycomb structures. One type of apparatus involves enveloping a sample in a rubber boot, immersing the enveloped sample in hydraulic oil and applying isostatic pressure to the sample from all directions. One drawback of this apparatus is that it does not simulate the true compressive forces encountered by catalyst supports during the canning operation. Furthermore, this type of apparatus is relatively large and stationary. In addition, the envelopment, loading and removal of the sample is time consuming, inconvenient for the operator and unclean because the enveloped sample is loaded directly into the hydraulic oil. Since the apparatus is too large to transport, samples must carried to and from the machine. Various apparatus exist for testing tubular products, however, these apparatus do not permit rapid loading, testing and unloading of the product. New methods of testing ceramic honeycomb structures, particularly in a production environment, are needed.
SUMMARY OF THE INVENTION
The invention relates to apparatus and methods for testing the compressive strength of ceramic honeycomb structures. In certain embodiments, a portable compressive strength testing apparatus is provided. According to other embodiments, samples can be easily and rapidly loaded, tested and unloaded from the apparatus. In some embodiments, the portability of the apparatus and the ease and speed of loading, testing and unloading samples facilitates the testing of large quantities of ceramic honeycomb structures. In other embodiments, a failure detector is provided to determine when a part has experienced failure that cannot be detected by visual inspection.
Advantages of the invention will be apparent from the following detailed description. It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a main housing and loading and unloading portion of the strength testing apparatus according to one embodiment of the invention;
FIG. 2 is an exploded perspective view of a main housing and a flexible member in a honeycomb structure compressive strength testing apparatus according to one embodiment of the invention;
FIG. 3 is an assembled cross-sectional view of a main housing used in a strength testing apparatus according to one embodiment of the invention; and
FIG. 4 is a perspective view of a strength testing apparatus on a cart according to one embodiment of the invention.
DETAILED DESCRIPTION
Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or carried out in various ways.
The invention provides apparatus and methods for testing the compressive strength of a ceramic honeycomb samples. Referring to FIGS. 1-4, an exemplary embodiment of an apparatus 10 for testing the compressive strength of ceramic honeycombs is shown. The apparatus 10 includes a main housing 12 having a generally cylindrical chamber 14 and a generally cylindrical, flexible member 16 disposed within the main housing 12 . The flexible member 16 defines a sample 17 loading and testing area 18 and a gap 20 between the flexible member and the main housing 12 . The gap 20 provides a fluid holding area 22 . A fluid inlet 24 and fluid outlet 26 are in fluid communication with a pressure generator 21 for supplying fluid under pressure to the fluid holding area 22 and to expand the flexible member 14 inwardly to provide uniform compressive force on the periphery of the sample 17 . A top plug 28 and a bottom plug 30 seal the chamber 14 during testing of the sample 17 . The apparatus 10 also includes a mechanism for automatically moving samples 17 in and out the sample loading and testing area. Preferably, the mechanism for moving the sample 17 in and out of the sample loading and testing area includes a retractable plunger 32 that is adapted to move the bottom plug 30 upwardly and downwardly. A top pad 34 is associated with the top plug 28 , and a bottom pad 38 is associated with the bottom plug 30 . The top pad 34 and bottom pad 38 are in contact with the sample 17 during testing, and should be made from a material that will not chip a ceramic part. The bottom pad 38 also provides lower support for the sample 17 during testing. Preferably, the plunger 32 is hydraulically or pneumatically activated. However, other mechanisms can be used to move sample in and out of the sample loading and testing area. For example, the sample 17 could be moved by a plate supporting the sample 17 attached to a movable screw type mechanism, or the sample could be raised by a support driven by a chain, pulley, belt or other suitable mechanism for raising or lower the sample 17 into the sample test area 18 .
As shown in FIG. 2, the flexible member 16 comprises a generally cylindrical main body 19 , a top flange 21 and a bottom flange 23 integrally formed with the main body 19 . The flanges 21 , 23 extend radially from the top and bottom of the main body. The flanges 21 , 23 also include integral gaskets 25 , 27 for sealing with the main housing 12 . The housing may further include a top recess 40 and a bottom recess (not shown) around the periphery of top and bottom surfaces of the main housing 12 . In certain embodiments, the gaskets 25 , 27 have a cross-sectional diameter large enough so that the gaskets 25 , 27 extend beyond the top and bottom recesses (see FIG. 1 ). A top sealing cap 42 and a bottom sealing cap 44 are secured to the main housing 12 such that the sealing caps 42 and 44 compress the gaskets 25 , 27 to form a fluid tight seal. As shown in the Figures, the sealing caps 42 , 44 are secured to the main housing 12 with a plurality of retaining members such as bolts 50 . However, the sealing caps 42 , 44 can be secured to the main housing 12 by other means such as by clamps.
The main housing 12 , the plugs 28 , 30 and the sealing rings 42 , 44 are preferably made from a metal capable of sustaining the forces generated by the pressure generator and required for compressive strength testing ceramic honeycomb samples. Typically, the chamber is pressurized to pressures between about 50 pounds per square inch and 250 pounds per square inch. The pads 34 , 38 are preferably made from a soft material such a polymer or polyurethane. The flexible member 14 is preferably made from polyurethane.
Referring to FIG. 1, preferably the top plug 28 , bottom plug 30 and the plunger 42 are retractable such that they can move towards and away from the sample testing area 18 to open and seal the testing area 18 . The top plug 28 can be retracted by a pneumatically or hydraulically controlled top plug actuator 52 or other suitable mechanism for moving the plug. The bottom plug 30 can be retracted by pneumatically controlled bottom plug actuator 54 or other suitable mechanism for moving the plug. In preferred embodiments, the bottom pad 38 for supporting the sample 17 can be moved in and out of sample chamber 18 by a pneumatically controlled bottom pad actuator 56 .
Referring to FIG. 4, preferably, the entire apparatus 10 is sized to fit on a portable cart 60 to facilitate use of the compressive strength testing apparatus 10 in various locations of manufacturing plant. Other optional features of the strength testing apparatus include an operator control panel 62 , and an enclosure 64 for housing electrical, pneumatic and hydraulic controls (not shown). The main housing 12 , the top plug 28 and the bottom plug 30 and their associated actuators are preferably housed in an enclosure 66 . The main housing 12 can be secured to a mounting bracket 68 associated with the cart 60 . The top plug 28 and actuator can be mounted on a movable stage 70 capable of moving in the direction of arrow 71 . Movable stage can be moved with a pneumatic or hydraulic control system. The inlet 24 and outlet 26 are in fluid communication with a pressure generator, preferably a pressure generator able to produce hydraulic pressure. Preferably, the inlet 24 and outlet 26 are connected to the pressure generator by high pressure hoses and quick connect/disconnect fittings (not shown).
According to certain embodiments, a sensor (not shown) is included and is connected to the testing area and the hydraulic and pneumatic controls for determining failure of the sample during testing. It will be understood that complete or catastrophic failure of the part can be determined by visual inspection of the sample or by detection of an audible crack. However, in certain instances, the part may not catastrophically fail, and a sensor can be included to detect failure of the part. Such sensors may include a pressure sensor connected to the hydraulics of the apparatus to monitor sudden and rapid changes in pressure indicative of a part failure. Upon detection of a sudden pressure change, the apparatus 10 can be equipped with an alarm to alert the operator, or the apparatus can be configured to shut off upon activation of an alarm. Another type of sensor that can be operably connected to the test area of the apparatus is an acoustic sensor capable of detecting cracking in the sample that is not audibly detectable by a human. The acoustic sensor can be connect to an audible and/or visual alarm to alert an operator, or the machine can be configured to shut down upon detection of a crack in a sample.
In use, the apparatus 10 is located in a convenient location for testing honeycomb samples in a manufacturing facility. The stage 70 supporting the top plug 28 and actuator is moved away from the main housing 12 so that sample testing area 18 can be loaded with a sample. The bottom plug 30 is moved upwardly into a closed position by engaging the bottom plug actuator 54 , and then the bottom pad 38 is raised to the top of the sample loading area 18 by engaging the bottom pad actuator 57 . A sample 17 is loaded on the bottom pad 38 , and the bottom pad actuator is engaged to lower the sample 17 into the sample testing area 18 . The stage 70 supporting the top plug 28 is moved so that the top plug is located above the sample testing area 18 . The top plug actuator is engaged to close the top plug over the sample testing area 18 . The pressure generator then supplies fluid pressure through the inlet 24 to the desired testing pressure for the sample 17 . Fluid fills the fluid holding area 22 , and pressure from the fluid causes the flexible member 16 to exert a compressive force on the periphery of the sample 17 . After the sample has been tested to the desired pressure, a signal is sent to the pressure generator, and the fluid exits the fluid holding area 22 through outlet 26 . The top plug 28 is then moved upwardly away from the sample testing area, and the stage 70 supporting the top plug is moved away from the sample testing area 18 so that the sample 17 can be unloaded. The bottom pad actuator 56 engages to raise the sample out of the sample testing area 18 so that an operator can remove the sample and load another sample. It will be understood that most of the steps described above, with the exception of the operator loading and unloading the sample on and off the bottom pad are preferably automated and controlled by a control system. In preferred embodiments, the apparatus 10 is adapted to load, test, and unload a sample in less than about 30 seconds, and more preferably, in less than about 15 seconds. Samples can be loaded and unloaded by an operator quickly and easily, without having to reach into the sample testing area.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Methods and apparatus for testing the strength of ceramic honeycomb structures are described. The apparatus includes a chamber that utilizes a flexible, generally cylindrical member including integral flanges to apply compressive force to the periphery of the honeycomb structure. According to some embodiments, a portable apparatus with an open chamber is provided to allow for rapid testing of multiple honeycomb structures.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of the Taiwan Patent Application Serial Number 101141305, filed on Nov. 7, 2012, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a chemical mechanical polishing conditioner, and more particularly to a chemical mechanical polishing conditioner which may provide deformation compensation for a substrate.
[0004] 2. Description of Related Art
[0005] Chemical mechanical polishing (CMP) is a common polishing process in various industries, which can be used to grind the surfaces of various articles, including ceramics, silicon, glass, quartz, or a metal chip. In addition, with the rapid development of integrated circuits, chemical mechanical polishing becomes one of the common techniques for wafer planarization due to its ability to achieve whole planarization.
[0006] During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer is removed by a polishing pad in contact therewith (or semiconductor element) with optional use of slurry, through the chemical reaction and mechanical force. When the polishing pad has been used for a certain period of time, the polishing performance and efficiency are reduced because the debris produced in the polishing process may accumulate on the surface of the polishing pad. Therefore, a conditioner can be used to condition the surface of the polishing pad, such that the surface of the polishing pad is re-roughened and maintained at an optimum condition for polishing. In the process for manufacturing a conditioner, it is necessary to dispose an abrasive layer by mixing abrasive particles and a binding layer on the substrate surface; and to fix the abrasive layer to the surface of the substrate by brazing or sintering methods. However, during curing of the abrasive layer, the surface of the substrate may be deformed because of the difference in thermal expansion coefficient between the abrasive layer and the substrate, thus destroying flatness of the abrasive particles of the conditioner and thereby adversely affecting the polishing efficiency and service life of the conditioner.
[0007] Conventionally, the surface flatness of a chemical mechanical polishing conditioner is typically controlled by two ways. One way is to dispose the abrasive particles and the binding layer on the surface of the substrate, followed by pressing down the abrasive particles using a rigid plate to embed and fix the abrasive particles into the abrasive layer such that the surfaces of the abrasive particles and the rigid flat may have the same flatness. Another way is to dispose the abrasive particles into a recess of a mold, followed by covering the non-working surface of the abrasive particles with a binding layer and a substrate, and performing heat curing, and finally, flipping the mold upside down to separate the cured chemical mechanical polishing conditioner from the recess of the mold. However, in the above two methods for manufacturing the chemical mechanical polishing conditioner, during heat-curing the binding layer, the difference in thermal expansion coefficient between the binding layer and the substrate may result in deformation of the substrate of the chemical mechanical polishing conditioner after curing, which in turn results in deformation of the surface of the chemical mechanical polishing conditioner and destroys the flatness of the abrasive particles of the conditioner.
[0008] Therefore, what is needed is to develop a chemical mechanical polishing conditioner with surface flatness, which cannot only avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, but also control the surface flatness of the chemical mechanical polishing conditioner.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a chemical mechanical polishing conditioner, to avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, so as to achieve the surface flatness of the chemical mechanical polishing conditioner.
[0010] To achieve the above object, the present invention provides a chemical mechanical polishing conditioner, comprising: a planar substrate having a planar surface; a binding layer disposed on a surface of the planar substrate; and a plurality of abrasive particles embedded in a surface of the binding layer and fixed to the surface of the planar substrate by the binding layer, wherein, tips of the abrasive particles have a leveled height.
[0011] In the chemical mechanical polishing conditioner of the present invention, the planar substrate may be formed from a non-planar substrate which is deformed during curing the binding layer, wherein a surface of the non-planar substrate has a center surface and an outer edge surface, and a working surface is formed between the center surface and the outer edge surface.
[0012] In the chemical mechanical polishing conditioner of the present invention, the working surface may have a non-planar contour, wherein the non-planar contour may be spherical or non-spherical.
[0013] In the chemical mechanical polishing conditioner of the present invention, a height difference between the center surface and the outer edge surface may be 5-5000 μm. In a preferred aspect of the present invention, a height difference between the center surface and the outer edge surface may be 120 μm.
[0014] In the chemical mechanical polishing conditioner of the present invention, the planar substrate may be made of stainless steel, mold steel, metal alloy, or ceramic material, etc. In a preferred aspect of the present invention, the planar substrate may be made of type 316 stainless steel having a thermal expansion coefficient of about 16 ppm/° C.
[0015] In the chemical mechanical polishing conditioner of the present invention, the planar substrate may have a thickness of 3-50 mm and a diameter of 10-360 mm. In a preferred aspect of the present invention, the planar substrate may have a thickness of 6 mm and a diameter of 100 mm.
[0016] In the chemical mechanical polishing conditioner of the present invention, the binding layer may be a brazing layer, a resin layer, a electroplating layer, or a ceramic layer. In a preferred aspect of the present invention, the binding layer may be a brazing layer. The brazing layer may be at least one selected from the group consisting of iron, cobalt, nickel, chromium, manganese, silicon, aluminum, and combinations thereof, having a thermal expansion coefficient of about 14-15 ppm/° C.
[0017] In the chemical mechanical polishing conditioner of the present invention, the abrasive particles may be diamond or cubic boron nitride. In a preferred aspect of the present invention, the abrasive particles may be diamond. In addition, in the chemical mechanical polishing conditioner of the present invention, the abrasive particles may have a particle size of 20-450 μm. In a preferred aspect of the present invention, the abrasive particles may have a particle size of 200 μm.
[0018] Another object of the present invention is to provide a chemical mechanical polishing to provide a method for manufacturing a chemical mechanical polishing conditioner to obtain the above-described chemical mechanical polishing conditioner, and effectively avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, so as to achieve the surface flatness of the chemical mechanical polishing conditioner.
[0019] To achieve the above object, the present invention provides a method for manufacturing a chemical mechanical polishing conditioner, comprising: (A) providing a non-planar substrate; (B) providing a binding layer disposed on the surface of the non-planar substrate; (C) providing a plurality of abrasive particles embedded in a surface of the binding layer, and (D) heat curing the binding layer, such that the non-planar substrate is deformed into a planar substrate during curing the binding layer, and the abrasive particles are fixed to a surface of the planar substrate by the binding layer; wherein, after step (D), tips of the abrasive particles have a leveled height.
[0020] In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the surface of the non-planar substrate has a center surface and an outer edge surface, and a working surface is formed between the center surface and the outer edge surface.
[0021] In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the working surface may have a non-planar contour, wherein the non-planar contour may be spherical or non-spherical.
[0022] In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, a height difference between the center surface and the outer edge surface may be 5-5000 μm. In a preferred aspect of the present invention, a height difference between the center surface and the outer edge surface may be 120 μm.
[0023] In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the method for heat curing the binding layer may be brazing, heat-curing, ultraviolet radiation curing, electroplating, or sintering. In a preferred aspect of the present invention, the method for heat curing the binding layer may be brazing.
[0024] In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the abrasive particles may be diamond or cubic boron nitride. In a preferred aspect of the present invention, the abrasive particles may be diamond. In addition, in the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the abrasive particles may have a particle size of 20-450 μm. In a preferred aspect of the present invention, the abrasive particles may have a particle size of 200 μm.
[0025] In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, in the aforementioned step (C), the abrasive particles may be embedded in the surface of the binding layer by a template, a platen, or a temporary mold.
[0026] In summary, according to the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the problem of the deformation of the substrate of the chemical mechanical polishing conditioner during curing may be effectively solved, and the surface flatness of the chemical mechanical polishing conditioner may be improved, thereby increasing the polishing efficiency and service life of the conditioner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0028] FIGS. 1A to 1D show a conventional process flow for manufacturing a chemical mechanical polishing conditioner.
[0029] FIGS. 2A to 2E show another conventional process flow for manufacturing a chemical mechanical polishing conditioner.
[0030] FIGS. 3 A to 3 C′ show a further conventional process flow for manufacturing a chemical mechanical polishing conditioner.
[0031] FIGS. 4A to 4C show a process flow for manufacturing the chemical mechanical polishing conditioner of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Hereinafter, the actions and the effects of the present invention will be explained in more detail via specific examples of the invention. However, these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby.
COMPARATIVE EXAMPLE 1
[0033] Refer to FIGS. 1A to 1D , showing the conventional process flow for manufacturing a chemical mechanical polishing conditioner.
[0034] First, as shown in FIGS. 1A and 1B , a binding layer 11 is formed on a working surface of a substrate 10 having a planar contour, and the abrasive particles 13 are employed, wherein the spacing and arrangement of the abrasive particles 13 are controlled by using template 12 while a rigid plate 14 is provided to press down the abrasive particles 13 .
[0035] Then, as shown in FIG. 1C , after the abrasive particles 13 are pressed down by the rigid plate 14 , the abrasive particles 13 are embedded and fixed in the abrasive layer 11 , and the surfaces of the abrasive particles 13 and the rigid flat 14 may have the same flatness.
[0036] Finally, as shown in FIG. 1D , the abrasive particles 13 are fixed to the surface of the substrate 10 by a heat-curing process through the binding layer 11 . However, the substrate 10 of the chemical mechanical polishing conditioner may be deformed after curing because of the difference in thermal expansion coefficient between the binding layer 11 and the substrate 10 , and thus the binding layer 11 and the abrasive particles 13 on the surface of the substrate are also deformed thereby deteriorating the flatness of the abrasive particles of the conditioner, wherein tips of the center abrasive particles 131 are relatively high, while the tips of the outer edge abrasive particles 132 are relatively low, resulting in a height difference H 1 between the center abrasive particles 131 and the outer edge abrasive particles 132 .
[0037] In Comparative Example 1, the binding layer 11 is made of common nickel-based metal brazing and the substrate 10 is made of stainless steel.
COMPARATIVE EXAMPLE 2
[0038] Please refer to FIGS. 2A to 2E , showing another conventional process flow for manufacturing a chemical mechanical polishing conditioner.
[0039] First, as shown in FIGS. 2A and 2B , a mold 25 is provided, wherein the mold 25 has a recess structure, and a binding agent 27 is disposed in the mold 25 . Then, abrasive particles 23 and a binding layer 21 are provided and fixed on a soft substrate 26 , and after that, the soft substrate 26 is disposed on the surface of the binding agent 27 in the mold 25 , and the abrasive particles 23 are attached to the surface of the recess in the mold 25 by the binding agent 27 , such that the abrasive particles 23 may be provided have the same flatness with the surface of the recess in the mold 25 .
[0040] Subsequently, as shown in FIG. 2C , an adhesive layer 28 and a substrate 20 are provided and attached onto the soft substrate 26 , such that the abrasive particles 23 on the surface of the soft substrate 26 and the binding layer 21 can be combined to the substrate 20 by the adhesive layer 28 , wherein the surface of the substrate 20 has a planar contour.
[0041] Then, as shown in FIG. 2D , the abrasive particles 23 are fixed to the substrate 20 by the binding layer 21 , the soft substrate 26 and the adhesive layer 28 through a heat curing process. However, the substrate 20 of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer 21 and the substrate 20 , resulting in deformation of the binding layer 21 on the surface of the substrate 20 and the abrasive particles 23 , thus destroying the flatness of the abrasive particles 23 of the conditioner, wherein the center abrasive particles 231 and the outer edge abrasive particles 232 have different tip heights.
[0042] Finally, as shown in FIG. 2E , the aforementioned cured chemical mechanical polishing conditioner is removed from the recess in the mold 25 , and the binding layer 21 on the surface of the substrate 20 and the abrasive particles 23 have been deformed, thereby destroying the flatness of the abrasive particles 23 on the surface of the chemical mechanical polishing conditioner, wherein tips of the center abrasive particles 231 are relatively high, while the tips of the outer edge abrasive particles 232 are relative low, such that a height difference 112 between the center abrasive particles 231 and the outer edge abrasive particles 232 is formed.
[0043] In Comparative Example 2, the binding layer 21 is made of common nickel-based metal brazing, the substrate 20 is made of stainless steel, the binding agent 27 is wax, and the soft substrate 26 is a metal foil.
COMPARATIVE EXAMPLE 3
[0044] Refer to FIGS. 3 A to 3 C′, showing a further conventional process flow for manufacturing a chemical mechanical polishing conditioner. The manufacturing process of Comparative Example 3 is substantially the same as the above Comparative Example 1, except that the substrate in Comparative Example 1 or Comparative Example 2 is selected to have a planar contour, while the substrate in Comparative Example 3 is selected to have a non-planar contour.
[0045] First, as shown in FIG. 3A , a substrate 30 having a non-planar contour is provided, wherein a working surface 303 having a linear surface is formed between the center surface 301 and the outer edge surface 302 , and the height of the substrate is gradually increased from the center surface 301 to the outer edge surface 302 . In addition, the height of the center surface 301 is lower and the outer edge height of the surface 302 is higher, such that a height difference H 3 between the center surface 301 and the outer edge surface 302 is formed.
[0046] Next, as shown in FIG. 3B , a binding layer 31 and the abrasive particles 33 are disposed on the working surface 303 of the substrate 30 , wherein the binding layer 31 and the abrasive particles 33 may be optionally disposed by the method disclosed in Comparative Example 1 or Comparative Example 2 to control the arrangement or surface flatness of the abrasive particles 33 .
[0047] Then, as shown in FIG. 3C , the abrasive particles 33 are fixed to the substrate 30 by the binding layer 31 through a heat curing process. However, the substrate 30 of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer 31 and the substrate 30 , resulting in deformation of the binding layer 31 on the surface of the substrate 30 and the abrasive particles 33 , thus destroying the flatness of the abrasive particles 33 of the chemical mechanical polishing conditioner.
[0048] In Comparative Example 3, the binding layer 31 is made of common nickel-based metal brazing, and the substrate 30 is made of stainless steel. In Comparative Example 3, since the thermal expansion coefficient of the substrate 30 is selected to be higher than that of the binding layer 31 , the working surface 303 of the substrate 30 after heat-curing will present a upward-protruding curved surface, wherein tips of the center abrasive particles 331 and the tips of the outer edge abrasive particles 332 are relatively low, while tips of the therebetween abrasive particles 333 are relatively high.
[0049] Further, FIG. 3 C′ shows another aspect of Comparative Example 3. If the thermal expansion coefficient of the selected substrate 30 is lower than that of the binding layer 31 ′, the substrate 30 of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer 31 ′ and the substrate 30 , resulting in deformation of the binding layer 31 ′ on the surface of the substrate 30 and the abrasive particles 33 , and destroying the flatness of the abrasive particles 33 ′ of the chemical mechanical polishing conditioner, the working surface 303 ′ of the substrate 30 after heat-curing will present a downward-protruding curved surface, wherein tips of the center abrasive particles 331 and the tips of the outer edge abrasive particles 332 ′ are relatively high, while tips of the therebetween abrasive particles 333 ′ are relatively low.
EXAMPLE
[0050] Please refer to FIGS. 4A to 4C , showing the process flow for manufacturing the chemical mechanical polishing conditioner of the present invention. The manufacturing process of this Example is substantially the same as the above Comparative Example 3, except that the working surface of substrate in this Example is selected to have a non-planar contour, while the working surface of the substrate in Comparative Example 3 is selected to have a linear contour.
[0051] First, as shown in FIG. 4A , a substrate 40 having a non-planar contour is provided, wherein a working surface 403 having a non-planar surface is formed between the center surface 401 at and the outer edge surface 402 , and the non-planar surface may comprise a spherical contour or a non-spherical contour. In this Example, the working surface 403 has a non-spherical curved contour. In addition, the height of the center surface 401 is relative low and the height of the outer edge surface 402 is relatively high, such that a height difference H 4 between the center surface 401 and the outer edge surface 402 is formed. In this Example, the substrate 40 is a type 316 stainless steel having a thermal expansion coefficient of about 16 ppm/° C., and the substrate 40 has a diameter of 100 mm and a thickness of 6 mm. The height difference H 4 formed between the center surface 401 and the outer edge surface 402 is 120 μm. That is, the height difference H 4 formed between the center surface 401 and the outer edge surface 402 is 2% of the thickness of the substrate 40 .
[0052] Then, as shown in FIG. 4B , a binding layer 41 and abrasive particles 43 are disposed on the working surface 403 of the substrate 40 , wherein the binding layer 41 and the abrasive particles 43 may be optionally disposed by the method disclosed in Comparative Example 1 or Comparative Example 2 to control the arrangement or surface flatness of the abrasive particles 43 . In this Example, the abrasive particles 43 are diamond having a particle size of 200 μm.
[0053] After that, as shown in FIG. 4C , the abrasive particles 43 are fixed to the substrate 40 by the binding layer 41 through a heat curing process. However, the substrate 40 of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer 41 and the substrate 40 , resulting in deformation of the binding layer 41 on the surface of the substrate 40 and the abrasive particles 43 . However, in this Example, the binding layer 41 is a brazing made of nickel, chromium, silicon, and boron, having a thermal expansion coefficient of about 14-15 ppm/° C., and since the thermal expansion coefficient of the substrate 40 is selected to be higher than the binding layer 41 , the working surface 403 of the substrate 40 after heat-curing will present a upward-protruding curved surface. Referring back to FIG. 4A , however, since the working surface 403 of the substrate 40 in this Example has a non-spherical curved contour, and the working surface 403 is trimmed to have a recessed contour before heat-curing, the substrate 40 will be deformed to compensate the recessed surface of the working surface 403 . Finally, the cured substrate 40 and the surface of the abrasive particles 43 show a high degree of flatness, and as a result, the tips of all the abrasive particles 43 (including the center abrasive particles 431 and the outer edge abrasive particles 432 ) have a leveled height.
[0054] It should be understood that these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby, and the scope of the present invention will be limited only by the appended claims.
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The present invention relates to a method for manufacturing a chemical mechanical polishing conditioner, comprising: (A) providing a non-planar substrate; (B) providing a binding layer disposed on the surface of the non-planar substrate; (C) providing a plurality of abrasive particles embedded in a surface of the binding layer, and (D) heat curing the binding layer, such that the non-planar substrate is deformed into a planar substrate during curing the binding layer, and the abrasive particles are fixed to a surface of the planar substrate by the binding layer; wherein, after step (D), tips of the abrasive particles have a leveled height. Therefore, the present can effectively improve the problem of thermal deformation of the substrate of the chemical mechanical polishing conditioner during a heat curing process, and enhance surface flatness of the chemical mechanical polishing conditioner.
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BACKGROUND OF THE INVENTION
The invention relates to air texturing of yarn and more particularly, to improvements in a fluid jet apparatus used to texture the yarn.
U.S. Pat. No. 4,259,768, of common assignee, discloses a self-stringing jet device which is compact and easy to string up. The jet includes a body, a yarn inlet section, a movable venturi and a rotatable cylindrical baffle located at the outlet end of the jet. The venturi may be set to a string up position or to an operating position by one or more adjustable camming surfaces on the rotatable cylindrical baffle. In these embodiments, the movable venturi is mounted to adjust the relative axial positions of the venturi and the yarn guiding element which is fixed in the jet body. The adjustments are located on the external parts of the jet and readily available to be changed by the operators to the detriment of the quality of the yarn being produced. More particularly, each operator's perception of what constitutes good quality yarn can vary from operator to operator. For example, each operator may set the same jet differently for what may be considered in his own opinion to be good quality yarn and such differences in settings through human error lead to undesirable nonuniformity from machine to machine or jet to jet.
SUMMARY OF THE INVENTION
A jet device has now been found which provides positive set points for string up and operating positions which cannot be adjusted, thus eliminating the possibility of human error. This jet device includes a body having yarn inlet and outlet ends connected by a central bore, means for introducing pressurized gas through a gas inlet into said bore, a venturi located in said bore at the outlet end of the jet, a yarn guiding element extending into the bore from the yarn inlet end of the jet, the yarn guiding element has a passage through it for guiding yarn from the yarn inlet to the venturi, and a cylindrical baffle located at the outlet end of the jet. The venturi is axially slidable in the body from a preset operating position to a string up position back to a preset operating position and is attached to a collar having a circumferential groove therein located inside the body at the outlet end of the body. Means which may be in the form of a rotatable flat sided rod positioned in mounting holes in the body and a ball stop engaging said groove are used to positively position the venturi in the optimum string up or operating positions depending on the rotational position of the flat sided rod.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the invention.
FIG. 2 is an enlarged section view of FIG. 1 taken along line 2--2 showing the jet in string up position.
FIG. 3 is an enlarged section view of FIG. 1 taken along line 2--2 showing the jet in operating position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, the major elements of the jet device are body 10, yarn guiding element 12, movable venturi 14 with its attached collar 16 and baffle 18 with its supporting bracket 20 attached to body 10. Yarn guiding element 12 is press fitted into body 10 at the inlet end of the jet and consists of a cone shaped entrance 13 in communication with the yarn exit orifice 15 of the yarn guiding element. The outer portion of the yarn guiding element comprises a cylindrical portion 17 with a conical tip 19. Fluid orifice 22 has its axis parallel to the axis of yarn passage 17 and is supplied with fluid such as compressed air through fluid connection 23. Venturi 14 is free to move axially within the body 10 and a seal is formed between the venturi and body by O-ring seal 24 seated in an annulus 25 in the body. The venturi 14 is press fitted into collar 16 and collar 16 is free to move within the recess 26 at the outlet end of the jet body. A circumferential groove 28 is formed in collar 26. a rod 30 extends through body 10 and engages groove 28. The rod is rotatable in both the body and the groove. A handle 32 is attached to the end of the rod so that the rod may be easily rotated. The rod is not completely circular but has a flat sided cut 31 in it which is coincident with the groove 28. A ball stop 34 positioned in hole 36 in the body 10 is restricted in its movement within the hole by the location of set screw 38 threaded into bracket 20 on one side and the edges of groove 28 on the other side.
The following procedure is used to set the optimum string up and operating procedures for the jet. Air pressure (approximately 140 psig) is applied to the jet through connection 23. With the collar 16 held in a fixed location within recess 28 by rod 30 (FIG. 2) the venturi is forced (using a machine press not shown) within the fixed collar towards the conical tip 19 of yarn guiding element 12 until the maximum amount of air is aspirating through cone shaped entrance 13. The collar is then fixed to the venturi via the set screw 40. Next the rod is rotated so that the flat 31 is in position shown in FIG. 3. This allows the collar 16 to move toward the outlet end of the jet under the force of the air pressure carrying with it venturi 14. The movement toward the outlet of collar 16 is defined by the ball stop 36 and its adjustment screw 38. When the adjustment screw is fully turned in, the ball stop holds the collar in the aspirating position. Since the diameter of the ball stop 36 is larger that the width of the groove backing off of set screw 38 allows the ball to move away from the groove to a location as shown in FIG. 3 which allows the air pressure to force the collar and venturi outward away from the yarn guiding element 12 a distance determined by the setting of screw 38 and the screw 38 is adjusted until the best operating point is reached for the jet. This is determined by the most stable delivery of yarn at the exit end of the jet or by maximizing the wind up tension of the yarn after it leaves the jet. The screw 38 is then cemented or fixed in place.
The operation of this device is as follows: when a yarn or yarns are to be strung up, rod 30 is turned by handle 32 to a position shown in FIG. 2 so that movable venturi is moved toward conical tip 19 thus restricting the flow of air until ambient air is aspirated through cone shaped yarn inlet section 13 into and through movable venturi 16. The operator then inserts yarn into the cone-shaped inlet 13 where the aspirated air assists in carrying the yarn through the venturi to the outlet end. The operator then rotates rod 30 to the position shown in FIG. 3 so that the movable venturi 16 is allowed to move away from conical tip 19 under the force of the air pressure within the jet until it reaches the optimum operating setting established by the location of ball stop 36.
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A self-stringing jet device which is compact and easy to string up includes a body, a yarn inlet section, a movable venturi and a cylindrical baffle located at the outlet end of the jet. The venturi may be moved from a string up position to an operating position between positive set points engaging the movable venturi located within the jet.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a toilet flushing device with water saving features, and, in particular, to a toilet flushing device with a dual flush mechanism which uses a single handle and a single flush valve to effect both a short flush and a long flush. In addition, the present invention relates generally to a toilet trapway reseal device which selectively directs water from the reseal water hose into the tank overflow tube.
Various dual flush toilet mechanisms have been developed over the years for the purpose of providing the option of a full or long flush cycle for solid waste, or a short or partial flush cycle for liquid waste to save water during flushes that do not require the use of a full flush cycle. Conservation of natural resources such as water is important. Toilets which use less water to flush waste are most desirable.
Prior art dual flush mechanisms characteristically fall into two general categories. The first type of device includes dual flush mechanisms that utilize two separate flush valves. The flush valve used for the full flush is located at a lower level in the tank than the flush valve used for the short flush cycle. An example of this type of dual flush mechanism construction is found in Brown U.S. Pat. No. 1,960,864. Brown describes a dual flush valve operating device for a flush toilet wherein two trip lever arms of different lengths have a common fulcrum and are independently pivoted as the handle is rotated clockwise or counterclockwise.
The second type of dual flush mechanism characteristically includes two separate handles, one to effectuate the long flush and the other to effectuate the short flush. Activation of either handle causes a single flush valve in the tank to be raised to different heights. For example, Harney U.S. Pat. No. 4,881,279 describes a two-handle system wherein turning of the first handle results in a regular, full flush, and turning of the second handle results in a partial raising of the flush valve to actuate a short or partial flush. Harney uses a complicated system to effect the short flush cycle.
Lester U.S. Pat. No. 2,001,390 uses a clutch device on the rod of the flush valve to hold the flush valve in a partial raised position during the short flush cycle.
Most users are accustomed to a toilet with a single handle, and most toilets use a single flush valve as part of the toilet tank construction. Accordingly, an improved dual flush device for a toilet tank having a single flush valve actuated by a single handle for effecting either a short flush cycle or a long flush cycle is desired. It would also be desirable to provide such a dual flush device that can be retrofitted to a conventional toilet tank.
Another source of wasted water in a toilet tank occurs through the reseal water hose. After a toilet is flushed, the tank must be refilled with fresh water. In addition, some water must be supplied to the bowl or the trapway during refilling of the tank to insure that the trapway is resealed. In conventional toilets, the reseal water hose extends from the tank inlet water control and directs water into the tank overflow tube (which leads to the bowl or trapway) the entire time that the tank is refilling. This causes a waste of water since once the trapway is resealed, excess water will flow into the drain.
Furthermore, a dual flush device in the toilet tank complicates the water flow operation since two different refill patterns are required. Because the refill cycle after the long flush duration is greater than the short flush duration in a dual flush application, the volume of reseal water dedicated to insuring that the trapway in the toilet bowl is resealed after the long flush is typically greater than the volume of water dedicated to resealing the trapway during the short cycle. This may result in an underfilled trapway seal for the short flush which can create a health hazard. Yet, on the other hand, during the long flush, there is an overfilled trapway seal which wastes water that could have been better utilized, for example, for flushing solid waste and refilling the tank.
Prior art water reseal constructions have identified this problem of wasted water from the reseal hose and have attempted, in a less than completely satisfactory way, to provide a solution. For example, Lazar U.S. Pat. No. 5,341,520 describes a dual capacity toilet flusher where the end of the reseal hose is supported on a movable platform construction which selectively moves the refill hose horizontally away from the overflow tube when the bowl is refilling. Comparetti U.S. Pat. No. 4,910,812 describes a complicated toilet system wherein the overflow tube pivots out of the path of the reseal hose water during part of the flush cycle.
However, heretofore, an acceptable, reliable and simple reseal water hose assembly has not been provided which can permit the reseal water hose to direct water into the tank during part of the flushing cycle and thereafter permit the reseal water hose to direct water into the overflow tube to reseal the trapway, while providing the same amount of water during the long and short flush cycles.
Accordingly, an improved reseal water hose assembly that reduces unnecessary water consumption and assists in the filling of the toilet tank in order to effectuate a more efficient refill cycle is desired. In addition, a trapway reseal assembly that delivers an appropriate volume of reseal water to the trapway regardless of the flush cycle, and which can utilize the excess water flowing from the reseal hose by redirecting this water directly into the tank, is desired.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the present invention, a dual flush device for a toilet tank having a flush valve actuated by a pivotable actuation arm for effecting both a short flush cycle and a long flush cycle, is provided. The dual flush device includes a cam rotatably supported on the toilet tank adjacent the actuation arm. The cam, when rotated in a first direction, acts to press against and pivot the actuation arm to effect the long flush. When the cam is rotated in a second direction, the cam presses against and pivots the actuation arm to effect the short flush. The dual flush device also includes a lever pivotably supported with respect to the actuation arm between a first position out of blocking contact with the actuation arm and a second position where the lever blocks the actuation arm for a predetermined period of time when the cam is rotated in the second direction to hold the actuation arm in a partially raised position. A float is coupled to the lever for determining the predetermined period of time. The float acts to pivot the lever into the second position when the cam is rotated in the second direction.
In a preferred embodiment, the dual flush device includes a single handle for selectively rotating the cam in the first direction and the second direction.
According to another aspect of the present invention, a trapway reseal assembly is provided. A doughnut-shaped float rides along the overflow tube in the toilet tank with the changing water level in the tank. The end of a reseal water hose is supported on the float and selectively directs water into the overflow tube or the tank depending on the height of the float.
Accordingly, it is an object of the present invention to provide an improved toilet flushing device with water saving capabilities.
Another object of the present invention is to provide an improved dual flush device for use in a toilet tank that requires only a single flush valve actuated by a single handle for effecting both a short flush cycle and a long flush cycle.
Yet another object of the present invention is to provide an improved toilet construction that reduces unnecessary water consumption.
Still another object of the present invention is to provide an improved trapway resealing assembly.
Another object of the present invention is to provide an improved trapway resealing assembly for use in toilets with both a long flush cycle and a short flush cycle.
Yet another object of the present invention is to provide an improved trapway resealing assembly that reduces unnecessary water consumption and assists in the filling of the toilet tank in order to effectuate a more efficient refill cycle.
Still another object of the present invention is to provide an improved trapway resealing assembly that delivers an equal quantity of reseal water to the trapway regardless of the flush cycle and utilizes the unnecessary water flowing from the reseal tube by redirecting this water directly into the tank.
A still further object of the present invention is to provide a toilet flushing device with water saving features that can be retrofitted into a conventional toilet tank.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a front elevational view of a toilet with a toilet tank shown partially cut away having a dual flush mechanism and reseal water hose assembly constructed in accordance with a preferred embodiment of the present invention;
FIG. 2 is a top plan view of the toilet and tank of FIG. 1, with the tank cover removed;
FIG. 3 is a rear perspective view of the dual flush mechanism constructed in accordance with a preferred embodiment of the present invention;
FIG. 4 is an exploded perspective view of the dual flush mechanism depicted in FIG. 3;
FIG. 5 is a rear elevational view of the dual flush mechanism in accordance with the present invention, shown prior to the commencement of a flush cycle;
FIG. 6 is a rear elevational view of the dual flush mechanism in accordance with the present invention after the handle has been rotated to commence the long flush cycle;
FIG. 7 is a cross-sectional view taken along lines 7--7 of FIG. 6;
FIG. 8 is a rear elevational view of the dual flush mechanism in accordance with the present invention after the handle has been rotated to commence the short flush cycle;
FIG. 9 is a partial top plan view of the dual flush mechanism of FIG. 8;
FIG. 10 is a top plan view of the reseal water hose assembly constructed in accordance with a preferred embodiment of the present invention; and
FIGS. 11 through 14 depict the reseal water hose operation during the long and short flush cycles in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first made to FIGS. 1 and 2 of the drawings which depict a toilet, generally indicated at 20, having a toilet bowl 21 and a toilet tank 22. Toilet tank 22 includes a removable tank cover 23. Toilet tank 22 also includes a dual flush mechanism, generally indicated at 30, and a trapway reseal assembly, generally indicated at 50, both constructed in accordance with the present invention.
A water inlet control assembly 70 is provided in the tank for controlling the refilling of toilet tank 22 with fresh water after flushing has occurred. Some fresh water is supplied to a water reseal hose 52 during refilling of the tank. Tank 22 includes an overflow tube 24 which leads to bowl 21 or directly to the toilet trapway below the toilet. Tank 22 also includes a flush valve, generally indicated at 60, which provides a conduit for water to flow from tank 22 to bowl 21 when the toilet is flushed. Flush valve 60 includes a valve seat 62 and a pivotable flush valve flapper 64 which opens and closes the valve.
Reference is now made additionally to FIGS. 3 and 4 to describe the construction of dual flush mechanism 30. Dual flush mechanism 30, as described below in detail, is activated by a handle 32 on the outside of tank 22 which can be rotated in a counterclockwise direction in the direction of arrow A to effectuate a long or full flush cycle and in a clockwise direction in the direction of arrow B to effectuate a short or partial flush cycle.
Dual flush mechanism 30 includes an L-shaped pivotable actuation lever or arm 34 having a first arm 35 and a second arm 36. In a preferred embodiment, first arm 35 is longer than second arm 36. Free end 35a of first arm 35 of actuation lever 34 is coupled to flapper 64 of flush valve 60 through a chain or other flexible linkage 66. Free end 35a of first arm 35 may include several openings 33 spaced therealong to permit fastening of chain 66 thereto at a desired position. A separate flush valve float 67 is attached along chain 66 to hold flapper 64 open during the long flush cycle as described below in detail.
Dual flush mechanism 30 also includes a short flush lever 80 in the form of a pivotable L-shaped bellcrank. A partial flush float 84 is removably coupled to short flush lever 80 through a float rod 86, preferably using a threaded thumb nut 87, although other fastening devices can be used.
As can be seen, dual flush mechanism 30 may be mounted to toilet tank 22, preferably on a front wall thereof. Moreover, the exact position of the mounting can vary within reason, keeping in mind the importance of access to handle 32 and that dual flush mechanism 30 must not be mounted so as to cause interference with pre-existing structure in the conventional tank. In an exemplary embodiment, and as shown in FIG. 3, an opening is formed in the front wall of toilet tank 22 thereby permitting dual flush mechanism 30 to be mounted thereon by positioning the tank wall between a backing plate 38 and a threaded nut or other escutcheon 40. Backing plate 38 includes an opening 38a through which a shaft 31 which rotates with handle 32 extends. However, it is also contemplated that backing plate 38 may be formed as part of the inside wall of the toilet tank itself.
Handle 32 is coupled to dual flush mechanism 30 through shaft 31. A cam 42 in the form of an asymmetrical shoe having a first toe 43 and a second toe 44 is secured to shaft 31 using a screw or the like so as to be rotatable therewith. Cam 42 may be configured in alternate shapes such as a kidney bean shape, so long as cam 42 can operate to contact and lift actuation lever 34 when rotated clockwise and counterclockwise. However, it is noted that other forms of single handle actuation, such as different amounts of rotation, can be used to effectuate the different flush cycles.
In an exemplary embodiment, actuation lever 34 is pivotably supported by a pin 38b extending from backing plate 38. This mounting construction permits actuation lever 34 to be rotatable in a plane essentially parallel to backing plate 38. Arms 35 and 36 of actuation lever 34 may be constructed so as to be rigidly fixed together, or actuation lever 34 may be a unitary member. In addition, arm 35 may also be of a unitary member or may include a joint 78 which permits first arm 35 to be moveable horizontally with respect to second arm 36 to allow for different configurations. A pin 79, screw or the like is mounted as part of joint 78 to secure the sections of actuation lever 34 together.
It is noted that the dual flush mechanism of the present invention works best when free end 35a of arm 35 is positioned at least substantially over flush valve flapper 64. As described in greater detail below, when actuation lever 34 is raised, flush valve flapper 64 is pulled off of flush valve seat 62. Therefore, if free end 35a of arm 35 is positioned above lush valve flapper 64, flushing can be effectuated in a most efficient manner. By providing joint 78, first arm 35 can be rotated about joint 78 to position the free end of arm 35 as desired to avoid interference with other components in the tank.
Short flush lever 80 is pivotably coupled to backing plate 38 through a joint 81 using a dowel, screw or pin 85 or the like. Short flush lever 80 is pivotally coupled to backing plate 38 in a direction transverse to actuation lever 34. Short flush lever 80 includes two legs 82 and 83. Leg 83 is coupled to float rod 86. A partial flush float 84 may be slidably coupled to float rod 86 to permit accommodation in a pre-existing conventional toilet tank and to control the length of the short flush cycle. By permitting partial flush float 84 to be manually repositioned along float rod 86, the dual flush mechanism can be configured to operate in conventional toilets.
In addition, and as particularly shown in FIGS. 4 and 9, float rod 86 can be mounted to leg 83 in various orientations. In this regard, leg 83 has a star-shaped opening 87 to permit an end 86a of float rod 86 to be inserted therein in various positions. End 86a of float rod 86 may include wings 86b and 86c which are accommodated by hole 87. Once positioned, a thumb nut 87a can be used to hold the float rod in place.
A wall stop 90 is provided to prevent the over-rotation of cam 75 as discussed below.
As shown in FIGS. 3 and 5, which depict a pre-flush configuration when the tank is full, leg 82 of short flush lever 80 rests against second arm 36 of actuation lever 34 as float 84 tends to be lifted by the water level in the tank.
Reference is now made to FIGS. 5-7 to describe the operation of the dual flushing mechanism in accordance with the present invention to provide a long or full flush.
Such long or full flush is initiated by rotating handle 32 counterclockwise from the front in the direction of arrow A. This rotation of handle 32 causes shaft 31 to also rotate which in turn causes cam 42 to rotate in the same direction. This rotation causes the long toe 43 of cam 42 to contact an upper portion of second arm 36 of actuation lever 34 thereby raising first arm 35 which in turn pulls on chain 66 to raise flapper 64. Float 67 is accordingly pulled up to the lowering surface of the water W (FIG. 6). The angle through which actuation lever 34 can be rotated and the maximum height reached by arm 35 is limited by wall stop 90. Wall stop 90, shown in an arcuate shape by way of example only and not in a limiting sense, may be mounted to backing plate 38 or be formed integral therewith.
When handle 32 is rotated in the counterclockwise direction of arrow A (when viewed in FIG. 1), short toe 44 of cam 42 contacts the lower edge of wall stop 90 thereby preventing cam 42 and hence handle 32 from rotating any further. In this long or full flush condition, flush valve flapper 64 is shifted to its fully open or buoyant position thereby allowing the water in the tank to empty into the bowl to flush the bowl. As the water level in the tank drops, float 67 also lowers (but remains on the water surface). Actuation lever 34 also lowers to its original position. When the water level drops to a predetermined level, flush valve flapper 64 closes and reseals flush valve seat 62 in the conventional manner, thus terminating the full flush cycle. The tank then begins to refill.
As depicted in FIG. 3, in the pre-flush condition when the tank is full, leg 82 presses against the side of arm 36 of actuation lever 34 due to the buoyancy of flush float 84. As depicted in FIG. 7, when the long flush cycle begins, short flush lever 80 initially rotates towards handle 32 in the direction of arrow C and would appear to prevent actuation lever 34 from returning to its original position after the tank empties. However, it is to be understood that after the long flush cycle begins, the water level in the tank begins to fall as water in the tank is delivered through the flush valve to the bowl. The lowering of the water causes partial flush float 84 to also fall, thereby rotating short flush lever 80 away from handle 32 out of the path of arm 36 of actuation lever 34 before flush valve flapper 64 covers and seals flush valve seat 62. Therefore, it can be seen that the presence of the short flush lever 80 does not affect the long or full flush cycle.
Reference is now made to FIGS. 8-9 which illustrate the operation of the dual flushing mechanism of the present invention during the short flush cycle. A partial or short flush is initiated by rotating handle 32 in the clockwise direction of arrow B (as viewed in FIG. 1). The rotation of handle 32 rotates shaft 31 which causes short toe 44 of cam 42 to contact a lower portion of second arm 36 of actuation lever 34 thereby raising first arm 35 of actuation lever 34 to a second predetermined height, which is less than the predetermined height in the long flush.
The amount of rotation and height is also limited by wall stop 90. In the clockwise direction, toe 43 contacts the top of wall stop 90 to prevent the over-rotation of actuation lever 34. Accordingly, flush valve flapper 64 is not raised off of flush valve seat 62 as high as it is raised during the long full flush cycle operation. Moreover, since float 67 is not raised sufficiently to rise to the water surface, flush valve flapper 64 is held open only due to the tension of chain 66, rather than by the float buoyancy as in the full flush.
As soon as actuation lever 34 is raised, the buoyancy of partial flush float 84 causes leg 82 of short flush lever 80 to rotate towards handle 32 and press against the face of cam 42 as depicted in FIG. 9. When handle 32 is released, leg 82 of short flush lever 80 will contact the inner surface 36a of second arm 36 of actuation lever 34 so as to block further downward movement and maintain first arm 35 of actuation lever 34 in an elevated position allowing flush valve flapper 64 to be held in a partially open position permitting water to flow from the tank to the bowl.
However, after the commencement of the short flush cycle, the water level begins to fall. As the water level falls, partial flush float 84 lowers with the corresponding water level in the tank. At a predetermined water level, the partial flush float 84 will have fallen a sufficient distance to cause short flush lever 80 to rotate back, thus disengaging leg 82 from arm 36 of actuation lever 34, thereby permitting actuation lever 34 to rotate and lower which in turn permits flush valve flapper 64 to close and reseal, thereby terminating the partial or short flush cycle.
As water refills in the tank in the conventional manner, flush float 84 rises in the tank and leg 82 of short flush lever 80 rotates about its pivotal axis to reset itself for the next flush action.
By providing a dual flush mechanism which allows the user to select either a full or partial flush by selected rotation of a single handle to selectively activate a single flush valve, an improved dual flush mechanism that conserves water is provided. A full flush is obtained by the rotation of a single handle in the counterclockwise direction. This rotation causes the cam or shoe to contact an actuation arm, thereby lifting the flush valve from its seat. Upward movement of the actuation arm is limited by a stop.
For a partial flush, the handle is rotated in the clockwise direction. This rotation causes the cam to contact the actuation lever, but raises the actuation lever a lesser amount. Similarly, upward movement of the actuation arm is limited by the stop. Release of the handle allows the short flush lever to temporarily hold the actuation in a partial raised condition, thereby keeping the flush valve in an unseated position allowing water to flow from the tank to the bowl. As the water level in the tank drops, the partial flush float also drops disengaging the short flush lever from the actuation lever. This permits the actuation arm to return to its pre-flush position and reseat the flapper onto the flush valve seat. With the refilling of the tank, the partial flush float rises, rotating the short flush lever to contact the actuation lever in preparation for the next flush cycle.
Reference is now made particularly to FIGS. 10 through 14, which depicts trapway reseal assembly 50. Assembly 50 includes a reseal water hose 52 having a free end 52a which is coupled to a reseal float 54. In the preferred embodiment, reseal hose 52 is coupled to reseal float 54 by means of a clip 53 or the like. Reseal float 54 is preferably in the shape of a doughnut and slidably supported to ride along overflow tube 24. Overflow tube 24 may also include a retaining pin 55 (FIG. 10) which prevents reseal float 54 from disengaging from overflow tube 24. In addition, overflow tube 24 may include a splash guard 56 (FIG. 10) to assist in directing water flow from hose 52.
Reference is now made specifically to FIGS. 11 through 14 which illustrate the operation of trapway reseal assembly 50 in accordance with the present invention. In a pre-flush configuration when the tank is full, float 54 is in its uppermost position as shown in FIG. 11. At this position, free end 52a is positioned to direct water in overflow tube 24. However, no water is flowing in the pre-flush condition since the inlet valve of the water control is closed.
After a long or short flush cycle is commenced, as water in the tank empties into the toilet bowl, the reseal float begins to lower with the tank water level. Distance X shown in FIG. 11 shows the distance that the reseal float 54 drops during a short flush cycle, while distance Y show the drop distance for a long flush. Once float 54 drops to the level shown in FIG. 12, reseal hose 52 is below the rim of overflow tube 24 and water from the reseal hose will be directed into the tank.
As the tank refills after the flapper has closed, the reseal float will begin to rise. Water from hose 52 will continue to be directed into the tank until the float hits the level of FIG. 13 where water begins to be directed into the overflow tube. It is specifically noted that the point at which reseal water is first redirected into the overflow tube is the same after either flush cycle, thus ensuring the same quantity of reseal water dedicated to sealing the trapway. As the water continues to rise, reseal hose 52 is again directly over overflow tube 24 so as to cause water to flow directly into overflow tube 24 as shown in FIG. 14. Water will be directed into the overflow tube until the tank is full.
The trapway reseal assembly of the present invention provides for excess water from the reseal hose to be used for refilling the tank. In addition, essentially the same amount of water will be delivered through the overflow tube to the trapway regardless of the length of the flush.
By providing a trapway reseal assembly where the reseal hose is mounted on a float which rides along the overflow tube, an improved dual flushing toilet system that channels an equal volume of reseal water dedicated to sealing the trapway of the toilet is provided. Regardless of the flush cycle, by providing a trapway reseal assembly where water is directed by the position of a reseal float, which itself is positioned by the water level within the tank, an improved reseal assembly is provided.
It will thus be seen that the objects set forth above, and those made apparent from the preceding description are efficiently obtained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
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A toilet flushing mechanism includes a dual flush device for effecting both a short flush cycle and a long flush cycle in a toilet tank including a flush valve actuated by an actuation arm. A cam operable by a handle is rotatably supported adjacent the actuation arm. When rotated in a first direction, the cam acts to press against and pivot the actuation arm to effect the long flush. When rotated in the second direction, the cam acts to press against and pivot said actuation arm to effect the short flush. A lever is pivotably supported with respect to the actuation arm and pivots between a first position out of blocking contact with the actuation arm and a second position where the lever blocks return of the actuation arm for a predetermined period of time when the cam is rotated in the second direction. A float is coupled to the lever for determining the predetermined period of time. The float acts to pivot the lever into the second position when the cam is rotated in the second direction.
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BACKGROUND OF THE INVENTION
The present invention relates to a wire end or forming section of a paper making machine, particularly a twin wire forming section, and more particularly to the application of pressure to the two wires of a twin-wire forming section for aiding fiber suspension quality.
The invention is developed from the twin-wire former disclosed in International Application WO 91/02842. Two endless forming wire belts form a twin-wire zone, which can be subdivided into three sections.
In the first section, the two wires run over a curved supporting surface of a supporting element, which is there preferably a forming cylinder. They there form a wedge shaped entry nip, to which the headbox directly transmits pulp suspension. In the region of the forming cylinder, some of the water in the fiber suspension is removed downward. Some of the water also penetrates upward through the top wire, on account of the tension of the top wire, and that water is removed by means of subatmospheric pressure. The dewatering pressure is in this case the same in the area where the wire belts wrap around the forming cylinder.
In the second section, there are a plurality of compliantly supported strips which bear against the bottom wire. Between each pair of support strips along the bottom wire, there is a respective fixedly supported strip bearing against the top wire.
The compliantly supported strips in the second section direct forces onto the inner surface of the bottom wire, i.e. the surface of the wire inside its endless loop form. The strips produce linear loads, which induce tolerances in the fiber suspension between the two wires on account of the minimal cross-sectional changes when the suspension flows through at a high operating rate. This avoids flocculation.
In the third section, both wire belts run over a further curved supporting surface of a support element. The support element is preferably in the form of a forming shoe having a curved surface.
The combination of already known features in this three section arrangement ensures relatively good paper web quality with respect to two sidedness, look through and uniformity of formation. However, quality requirements in these respects have increased, so that further improvements are desirable. It is intended that the improvements should also be achievable by means of a simpler configuration of supporting elements. A disadvantage of the above known arrangement is caused by the relative movement between the top wire and the rigid strips. The inner surface of the top wire, inside its loop form, is subject to the effects of wear. Also, due to the in line arrangement of the various supporting elements in the individual sections I, II and III, the wire end of the machine has considerable overall length.
EP 0 516 601 A1 publication discloses pressure elements in the form of flexibly designed blades that may be effective on the wire belts in the region of the individual supporting elements for intensifying the dewatering of the suspension, for accomplishing optimum basis weight distribution of the suspension and also for counteracting flocculation in the fiber suspension. The blades are arranged in such a way that their blade bodies lie substantially transverse to the web running direction and bear with part of their surfaces against one of the wire belts and press that belt against the supporting element. In the configurations described, the blades are effective only as pressure elements, not as water skimming elements.
The support elements take various forms, for example, a wire frame with a closed surface or a surface provided with an opening for the purpose of suction intake, or a forming cylinder or an element designed in the form of a strip.
The arrangement of the flexibly configured blades with respect to the wire belt supported by the supporting surface and also the flexibility of the blades are of significance for the magnitude of the pressure impulses which are introduced. In the configurations described, the magnitude of the pressure impulses is changed mechanically by spindles or pneumatically by hoses which bear against the blade body. By changing the cross section, these produce increased bending stress on the blade bodies and consequently produce an increase in the contact pressure of the part of the blade body bearing against the wire belt. The blade arrangement with the associated adjusting mechanism for changing the contact pressures is a relatively complicated structure. Thus, substantially only one installation position of the blades is possible. The magnitude of the contact pressures is dependent on the properties of the blades, and specifically on the flexibility of the blade material. In cases of low contact pressures, high blade flexibility and clotting of the fiber suspension, there is the risk of the blade body oscillating. The contact pressure and consequently the hydraulic pressure in the suspension or the pressure impulse effective in the suspension are also dependent on the blade angle. The effects of wear at the blade cutting edge result, however, in changing of the blade angle. This is found to be a particular problem if there is uneven wearing of the blade cutting edge over the width of the machine.
A further disadvantage of this configuration is that clots, which form from fine fibers which penetrate through the wire mesh during dewatering and which can form upstream and downstream of the blade, enter into a wedge which is formed, by the arrangement of the blade and the supporting surface, between the blade and the supporting surface and damage the wires there.
SUMMARY OF THE INVENTION
The invention is therefore based on the object of further developing the possibilities of intensifying dewatering and improving web quality by preventing flocculation in the fiber suspension in the forming section or wire end of a paper making machine such that the overall length of the wire end of the paper machine is reduced. Further, wear damage to at least one of the wire belts is to be reduced. It is intended to avoid the disadvantages of known configurations.
These objects are achieved by features of the invention. The wire end or forming section of a paper making machine is a twin wire section defined by two endless loop wire belts or wires between which fibrous suspension moves through the wire end. A supporting element, either in the form of a rotating cylinder or in the form of a support belt, has the wires passing over it in the twin wire zone. Pressure elements, in the form of strips, rods or even a shoe, are supported to apply pressure on the wire belts and directed toward the moving supporting surface. The pressure elements are placed along the twin wire path so that pressure free regions remain between neighboring pressure elements. The pressure elements are distributed over the entire width of the wire belts.
The most suitable support element, which is arranged in the twin-wire zone has a support surface against which the pressure elements act. The support surface moves or runs around, i.e. it is a forming cylinder with a rotatable jacket or a belt that moves around belt guide rolls. Use of this movable support surface produces the advantage that the effects of centrifugal force and introduced pressure impulses are added together to improve dewatering. Furthermore, friction on the wire belt is avoided, which contributes to reducing both belt wear and required drive power. However, a support surface is used which is preferably rigid in the direction in which the pressure acts on the wire belts and which cannot yield in that direction.
Using pressure elements to bring pressure to bear induces linear or punctiform loads, or in the case of a concave surface pressing shoe, planar loads, on the wire belt and produces turbulences in the fiber suspension between the wire belts, which contributes to reducing flocculation and improves dewatering.
The pressure elements, which are designed as strips, metering rods or concave pressing shoes, may either extend together or each on its own may extend over the entire wire width. It is also possible for the pressure elements to be mounted such that they can be tilted or turned. Preferably, there are always a plurality of the pressure elements arranged one behind the other along the web running direction and all extending substantially perpendicular to the running direction of the fiber suspension. Furthermore, the pressure elements are preferably able to be pressed compliantly against the inner, or inside the belt loop, surface of the respective wire belt. Their contact pressure is variably adjustable over time and also among the successively arranged pressure elements for each individual pressure element. An arrangement of the pressure elements at an angle to the running direction of the fiber suspension is likewise conceivable.
The pressure elements are preferably arranged such that the forces required for bringing the pressure elements to bear are directed perpendicularly to the wire belt. This offers the advantage that the full contact pressure can be directed as a pressing force onto the wire belts. However, directing the forces applied by the pressure elements at an oblique angle to the support surface is also possible, and then there is a component of force directed toward the wire belts and at the support surface.
The pressure elements are preferably mounted on a supporting frame which is in turn mounted on the machine frame. The supporting frame is swivelable away from the support surface. Where the support surface is on a forming cylinder, the supporting frame is preferably swivelable about the forming cylinder axis and is fastened on the housing of the forming cylinder mounting.
Other objects and features of the invention are explained below with reference to the drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows a cutaway portion from a twin wire forming section of a paper making machine;
FIGS. 2 to 4 schematically show structurally and functionally advantageous embodiments of the compliantly supported pressure elements in FIG. 1;
FIGS. 5 and 6 schematically show possible force introduction such that only one component of force acts in the direction of the forming cylinder axis;
FIGS. 7 and 7.1 schematically show the mounting of the pressure elements on a supporting frame which is fastened on the bearing housing of the forming cylinder axis;
FIG. 8 schematically shows an embodiment with a circulating belt as the supporting element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a partially cutaway portion of a schematic end view of a wire end of a twin-wire paper machine. There is a supporting element 1 in the form of a forming cylinder 1a. The cylinder jacket may have a closed surface. Alternatively, as represented in FIG. 1, the jacket may be provided with a multiplicity of bores, for example for storing pressed out filtrate or water or for the purpose of suction intake if two sided dewatering is desired. The forming cylinder 1a is a central unit that is wrapped by two endless wire belts 2 and 3 around part of its circumference, the area of wrap 4. Along this arc on the circumference of the forming cylinder and over a further section, these two wire belts are guided together and with each other form a twin-wire zone that extends up to a suction roll 5. In the immediate vicinity of the headbox 6, which is upstream of the twin-wire zone, the two wire belts first run together, one passing over a roll 7 and one over a cylinder. In particular, the wire belt 2 passes over the forming cylinder 1a while the wire belt 3 passes over a breast roll 7, so that at the beginning of the twin-wire zone, the two wire belts form with each other a wedge shaped entry nip 8 for the fiber suspension from the headbox.
The forming cylinder 1a is arranged within the loop of the endless wire belt 2. A device 9 in the illustrated embodiment comprises a supporting frame 18. The compliantly supported pressure elements 10 pass on forces to the belt loop inner surface of the wire belt 3 in the area of its wrap on the forming cylinder 1a. The device 9 is arranged within the loop of the endless wire belt 3. The compliantly supported pressure elements 10 are preferably configured as in U.S. Pat. No. 5,078,835. Each element may be designed as a strip 12 that extends along the cylinder 1a and across the web (FIG. 2). It may be designed as a roller, and the pressure element is then preferably a metering rod 14 (FIG. 3). A further possibility is to use a pressing shoe 15 as the pressure elements, having a concavely shaped pressing surface against the wire belt (FIG. 4). The compliantly supported pressure elements 10 direct forces, which are produced, for example, by springs or else pneumatically, onto the inner surface (inside the belt loop) of the wire belt 3. Depending on the type and shapes of the pressure elements used, they produce punctiform or linear loads on the wire belt.
As shown in FIGS. 2 and 3, the elements 10 are spaced apart along the path of the wire belts through the twin-wire zone. This provides pressure free regions between the pressure elements. Especially because the pressure elements are spaced apart, turbulences are produced in the fiber suspension between the two wire belts. These introduced pulsations have the effect of preventing flocculation, and more water is extracted on account of the pressure which is brought to bear and the associated changes in the wire tension. The part of the lateral surface of the forming cylinder in the area of wrap and extending over the entire wire width acts as the surface against which pressure is brought to bear.
The magnitude of the forces which are introduced, which produce a particular applied pressure due to the action of the pressure elements 10 on the inner surface of the wire belt 3, is variable and does not have to be kept constant over the entire area of wrap. On account of the shaping and arrangement of the pressure elements, the forces act in such a way that pressure free locations remain in the area in which the wire belts wrap around the forming cylinder. Pressure free regions and the compliant support of the pressure elements are needed to avoid accumulations in the fiber suspension caused by possible agglomerations of the fibers.
Force is introduced preferably radially with reference to the forming cylinder axis. However, there is also a possibility of force introduction in which only one component of the force acts radially to the forming cylinder axis (FIGS. 5 and 6). FIGS. 5 and 6 also illustrate the possibility of use of the force application with hybrid formers.
In FIG. 5, there is an initial Fourdrinier-type arrangement, in which the fiber suspension is preliminarily dewatered in a conventional way, i.e. preferably by passing the wire belt over strips 16. Then endless wire belt 3 wraps around a supporting element 1, which is here in the form of a solid jacket roll, over part of the surface of the roll. A further endless wire belt 2 is brought together with the wire belt 3 via a roll 17. In the area of wrap and over a further section in which the belts are guided together (which is not shown in more detail here), the two wire belts form a twin-wire zone.
The compliantly supported pressure elements 10, which are pressed against the inner surface of the wire belt 2, apply forces F in a direction such that only one force component F r acts radially, in the direction of the roll axis, that acts directly as a pressure on the wire belt 2. The tangential force component F t acts oppositely to the rotation direction of the solid jacket roll and acts as a friction force. The action of the pressure elements 10 produces an increase in the dewatering already induced in the fiber suspension by the circumferentially directed forces occurring upon rotation.
In an analogous design, the hybrid former shown in FIG. 6 includes the endless wire belts 2 and 3 which form a twin-wire zone. In their common area of wrap partly around the supporting element 1, the wires are engaged by compliantly supported pressure elements 10. Those elements 10 are in the form of strips that extend along the cylinder 1 and are mounted such that they can be turned or tilted, i.e. the strips are no longer mounted directly at their radially outer ends but in a radial region of each strip that is intermediate its length. Each strip is connected to a fixed bearing by means of a joint between the radial ends of the strip. Two lever arms are produced. At the end of the lever arm which is not bearing against the wire inner surface, a force is applied which is produced, for example, by springs. The resulting leverage produces a counteracting force of the same magnitude at the end of the other lever arm. The component F r , directed radially to the forming cylinder axis, of the counteracting force F is the pressure acting directly on the wire belt inner surface. The division of the forces and the effect of the individual force components are analogous to the arrangement represented in FIG. 5.
The possible way of mounting the pressure elements shown in FIG. 1 is preferably used. The entire apparatus 9 is located within the loop of the wire belt 3. The pressure elements 10 are mounted on a supporting frame 18, which is in turn supported on the machine frame and can be swiveled away. A further possibility, shown in FIGS. 7 and 7.1 is to mount the pressure elements on a supporting frame 19, which is preferably fastened on the housing 20 of the forming cylinder mounting axis.
The pressing of pressure elements against a wire belt which is supported against a supporting element offers particular advantages, especially for producing multi-ply paper, board and also very thin paper, that is wherever one sided dewatering is desired over a certain section. The supporting element should, however, have a closed supporting surface for the purpose of one sided dewatering.
FIG. 8 represents an embodiment of the invention as it can be used, for example, in board production. The part of a wire end represented comprises two areas, a Fourdrinier-type zone and a twin-wire zone. For applying the two plies of a fibrous web, two headboxes are provided, a primary headbox 21 and a secondary headbox 22. Following the primary headbox 21, the first ply of fiber suspension is preliminarily dewatered in a conventional way in the Fourdrinier-type area of the wire belt 2, preferably by passing the wire belt over strips 16 and by additional suction removal there. In the vicinity of the secondary headbox 22, the wire belt 2 contacts and then runs along on an endless belt 1c, which is guided by a plurality of guide rolls 23. The belt 2 runs together with the wire belt 3, which runs via a roll 7. At the beginning of the twin-wire zone, the two wire belts 2, 3 form with each other a wedge shaped entry nip 8 for the two plies of the fiber suspension. The endless belt 1c is arranged within the loop of the wire belt 2 and the belt 1c supports the belt 2 on its inner surface in the area of wrap of the wire belt 2 with the belt 1c. At the same time, the belt 1c supports the outer surface of the wire belt 3 in the area of wrap of the belt 3 with the belt 1c. The apparatus 9, which comprises the supporting frame and the pressure elements, is arranged within the loop of the wire belt 3 such that the belt 1c acts as the surface against which the pressure elements bear. The dewatering takes place on one side, i.e. in the direction of the pressure elements and away from the supporting surface of the supporting belt 1c , and is caused substantially only by the pressure impulses which are introduced. This is because in this region, the wire belts run virtually parallel on account of the guidance of the belt 1c over a plurality of guide rolls, which causes a straight path of the belt 1c between the individual guide rolls before and after the apparatus 9. The introduced pressure impulses induce turbulences in the fiber suspension and also prevent flocculation of the individual fibers. The two wire belts are separated from each other at the roll 24.
According to the desired dewatering effect and for the avoidance of flocculation, the form taken by the supporting elements/pressure elements arrangement may be varied for the respective application. Lining up a plurality of arrangements of supporting elements and pressure elements is possible.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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The wire end or forming section of a paper making machine is a twin wire section defined by two endless loop wire belts or wires between which fibrous suspension moves through the wire end. A supporting element, either in the form of a rotating cylinder or in the form of a support belt, has the wires passing over it in the twin wire zone. Pressure elements, in the form of strips, rods or even a shoe, are supported to apply pressure on the wire belts and directed toward the moving supporting surface. The pressure elements are placed along the twin wire path so that pressure free regions remain between neighboring pressure elements. The pressure elements are distributed over the entire width of the wire belts.
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BACKGROUND OF THE INVENTION
This invention generally relates to computer graphics display systems. More specifically, the invention relates to using ray tracing and backface culling technique to reduce the number of polygon intersection tests required to test effectively a ray against a set of polygons.
Backface Culling
Backface culling is a method of reducing the number of polygons rendered by a scan converting rendering architecture. The basic premise is simple: If we assume that the polygons we render are planar and only visible from one side, then we can easily detect when a polygon is facing away from the camera and eliminate it from consideration. The end result is that the time and computational resources which would have been wasted rendering invisible polygons can be used more efficiently on visible polygons. Since most computer graphics databases consist of polygon meshes of convex objects, approximately half of the polygons are backfacing when viewed from a single perspective. Therefore, the use of this technique effectively doubles the number of polygons processed by a scan converting rendering architecture in a given amount of time.
The traditional technique for culling backfacing polygons involves computing the normal vector of the plane in which each polygon lies and computing the dot product of this normal vector with the view vector from the camera focal point to a point on the surface of the polygon. If the sign of the dot product is positive, then the polygon is facing away from the camera (backfacing) and as such can be culled.
If the operation is performed in “camera coordinates” in which the virtual camera's center of projection is the origin of the coordinate system and the virtual camera's view direction vector is equal to the positive-Z axis of the coordinate system, then the computation of the dot product reduces to a simple sign check of the Z component of the polygon's plane normal vector. If the sign of the Z component is positive, then the polygon is backfacing and can be culled, otherwise the polygon must be drawn.
Recent articles disclose procedures that attempt to improve the efficiency of the process of backface culling in a scan converting rendering architecture. These articles include “Fast Backface Culling Using Normal Masks,” Zhangh, Hansen and Hoff, ACM Interactive 3D Graphics Conference, 1997 (Zhangh, et al.), and “Hierarchical Back-Face Computation,” Kumar, Subodh et al., Proceedings of 7th Eurographics Workshop on Rendering, June 1996, pp. 231-240 (Kumar, et al).
Zhang, et al. transforms unit normal vectors from 3D Cartesian coordinates (x,y,z) into polar coordinates (theta, phi) with an implied rho of 1.0. These 2D coordinates are used to generate a one-bit address within a backfacing mask—a two dimensional grid of single bit elements each of which corresponds to a solid angle on the unit sphere and represent all the unit normal vectors oriented within that solid angle. Any given unit vector can be mapped to one and only one bit in the 2D mask array. All of the normals mapped to one of the bits are said to belong to a “normal cluster” represented by that particular bit.
Each time the camera changes orientation a backfacing mask is constructed by determining for each bit in the mask whether all of the normals lying within the cluster are backfacing. This determination is performed by computing the dot products between the camera and each of the normals at the four corners of the represented solid angle. If all of the dot products are positive, then the bit is set in the backfacing mask, indicating that all normals in the cluster would be backfacing. This process is repeated for each cluster in the backfacing mask. After the backfacing mask has been generated, the polygons can be processed in turn. Each polygon's normal vector is computed from the cross product of its first and last edge vectors and is mapped to a normal cluster on the backfacing mask. If the corresponding backfacing mask bit is set, then the polygon is culled, otherwise the polygon is rendered. The mask technique described in Zhang, et al. offers a linear improvement in performance (forty to eighty percent faster) over traditional dot product evaluation, but can not achieve more than a one hundred percent increase in speed due to the fact that each polygon must be fetched and tested.
An approach advocated in Kumar, et al. groups normal vectors into a hierarchical tree of clusters based on position and orientation of polygons and their normal vectors. Each cluster divides space into three regions—the front, the back, and a mixed region—using separation planes. If the camera view point lies in the front region of a cluster, then all the polygons in the cluster are front facing. If the camera view point lies in the back region of a cluster, then all the polygons in the cluster are back facing. If the camera view point lies in the mixed region of a cluster, then sub clusters within the cluster must be evaluated because some of the polygons are front facing while others are backfacing.
This technique tests each cluster as a whole against the camera position and direction vectors without requiring that each triangle be explicitly fetched. In addition, this algorithm attempts to make use of frame-to-frame coherence. This algorithm does not eliminate one hundred percent of the backfacing polygons, but it eliminates between sixty and one hundred percent of these polygons, depending upon the polygon database.
Because the technique described in Kumar, et al. does not require each triangle to be tested, it is said to be a sublinear algorithm and as such has the potential to achieve an increase in speed of greater than one hundred percent. In practice, the algorithm achieves an increase in speed of between thirty and seventy percent when employed in a scan converting rendering architecture. This is because this algorithm significantly limits other optimizations, such as state sorting and vertex sharing, which are of critical importance to a scan converting architecture.
Ray Tracing
Ray tracing, also referred to as ray casting, is a technique employed in the field of computer graphics for determining what is visible from a vantage point along a particular line of sight. It was first reported as a technique for generating images and was first reported in “Some Techniques for Shading Machine Renderings of Solids”, Appel, AFIPS 1968 Spring Joint Computer Conference, 32, 37-45 (1968) (Appel). Many improvements have been published including support for reflections and shadows, soft shadows and motion blur, and indirect illumination and caustics. These improvements are discussed in “An Improved Illumination Model for Shaded Display,” Whitted, Communications of the ACM, Volume 23, Number 6, June 1980 (Whitted); “Distributed Ray Tracing,” Cook, Porter and Carpenter, Computer Graphics 18(3), July 1984, pp. 137-145 (Cook et al.); and “The Rendering Equation,” (Kajiya) Computer Graphics 20(4), August 1986, pp. 269 (Kajiya).
Ray tracing has also been used to compute form factors for iterative thermal transfer and radiosity computations [Wallace89]. Ray tracing is the most sophisticated visibility technique in the field of computer graphics, but it is also the most computationally expensive.
A ray is a half line of infinite length originating at a point in space described by a position vector which travels from said point along a direction vector. Ray tracing is used in computer graphics to determine visibility by directing one or more rays from a vantage point described by the ray's position vector along a line of sight described by the ray's direction vector. To determine the location of the nearest visible surface along that line of sight requires that the ray be effectively tested for intersection against all the geometry within the virtual scene and retain the nearest intersection.
An alternative to scan conversion for rendering an image involves directing one or more eye rays through each pixel in the image from the center of projection or points on the lens of the virtual camera. After basic visibility has been determined, ray tracing can be used to compute optically correct shadows, reflections, or refraction by firing secondary rays from the visibility points along computed trajectories.
Ray tracing renderers often employ secondary rays to capture the effects of occlusion, reflection, and refraction. Because these secondary rays can originate from points other than the center of projection of the virtual camera and can travel in directions other than the line of sight of the virtual camera a ray tracer cannot use the sign bit of the Z-component to determine if a polygon is backfacing. The polygon's normal vector could be precomputed in a preprocess and the dot product between the ray direction vector and this precomputed normal vector could be computed by the ray polygon intersection function. However, this approach would only yield a modest improvement at the cost of performing unnecessary memory accesses and dot product calculations for polygons which are front facing.
What would be better, and what is specified here, is a technique for grouping polygons together which have common orientation such that a single comparison between the ray direction and a representative direction for the group of polygons could eliminate large numbers of ray polygon intersection tests instead of just one. While each polygon is only processed once by a scan converting rendering architecture for each rendered frame, a ray tracer effectively processes each polygon millions of times (once for every ray cast) for each rendered frame. As a result, the effectiveness of such a technique would significantly reduce the computation, memory access, and rendering time necessary to produce images with ray tracing.
Ray Tracing Acceleration Using Intersection Test Reduction
To render a photorealistic picture of a 3D virtual scene with ray tracing requires hundreds of millions of rays and billions of ray intersection tests—depending upon the complexity of the scene, the number of light sources, and the resolution of the rendered image. It has been an active area of research to reduce the number of ray intersection tests while ensuring that accurate visibility is maintained. It is necessary for any ray intersection reduction technique to be conservative; that is, only irrelevant intersection tests should be eliminated. The method of testing a technique against this requirement is simple: A set of rays R tested against a set of targets T should result in a set of nearest intersection values I whether or not the ray intersection reduction technique is employed.
Prior art techniques for reducing the number of ray intersection calculations can be classified in three categories: Bounding volume techniques, spatial subdivision techniques, and directional techniques. Each of these techniques attempt to reduce the amount of computation required at the inner loop of the rendering process by preprocessing the scene into some sort of data structure that can be more efficiently traversed.
Bounding Volume Techniques
Bounding volume techniques were first introduced in an article “An Improved Illumination Model for Shaded Display”, Whitted, Communications of the ACM, Volume 23, Number 6, June 1980. This technique is based on the principal that if many geometric targets can be completely enclosed in a sphere in a rendering preprocess, then any rays which must be tested against the targets are first tested for intersection with the sphere. If a ray does not intersect the sphere, then it cannot intersect any of the geometric targets inside the sphere, and many ray intersection computations can be avoided. Other bounding volume techniques employ boxes, or groups of slabs or plane sets [Kay86] instead of spheres to provide a tighter fitting bounding volume. One such technique is discussed in “Ray Tracing Complex Scenes,” Kay and Kajiya, Computer Graphics 20(4), August 1986, p. 269.
The efficiency of bounding volume techniques is directly related to the tightness of the bound and inversely proportional to the complexity of the ray bounding volume intersection test. Spheres and boxes allow for very fast ray intersection computation, but there are frequently encountered cases where the target they attempt to bound is not tightly bounded by the sphere or box and a large number of unnecessary ray intersection calculations result. Conversely, a customized polygon mesh can provide an extremely tight bound, but can very easily require nearly as many (or more) intersection tests than the geometry it attempts to bound. Bounding volumes are best used in concert with spatial subdivision or directional techniques.
Spatial Subdivision Techniques
Spatial Subdivision techniques were first introduced in an article “Space Subdivision for Fast Ray Tracing,” Glassner, IEEE Computer Graphics and Applications, 4(10), October 1984, pp. 15-22. These techniques are significantly more efficient than bounding volume techniques but require more preprocessing work. Spatial Subdivision techniques divide space into uniform grids or octrees. For example, a procedure that uses uniforms grids is discussed in [Fujimoto85], and a procedure that uses octrees is described in the above-mentioned Glassner article. Each voxel (cell in the grid) enumerates the geometric targets which partially or completely lie within it and when the ray is tested against the octree or uniform grid only those cells which lie along the path of the ray are consulted. This aspect of these techniques significantly reduces the number of geometric targets which need to be tested against each ray.
Voxels and Octrees also provide a mechanism referred to as an early exit mechanism. The cells which lie along the path of the ray are tested starting with the cell nearest to the ray origin point and ending with the cell which is farthest along the ray's path. With this mechanism, if the ray intersects a geometric target within a cell, then the search may be halted after the remaining targets within the cell have been tested. The additional cells along the path of the ray are irrelevant because they lie beyond an intersection which is closer to the ray origin and as such any geometry within them would be occluded by that intersection. Another spatial subdivision techniques is described in [Kaplan85]. In this technique, Binary Separation Planes are used to subdivide space to reduce the number of target candidates.
Spatial subdivision techniques have matured and evolved into a number of different forms: Octrees, uniform grids, and BSP trees. They are simple to construct and traverse and offer an efficient early exit mechanism.
Directional Techniques
Directional techniques were first introduced in [Haines86]. These procedures attempt to use directional coherence to eliminate geometric targets from consideration in a manner similar to the manner that spatial subdivision techniques make use of spatial coherence to eliminate geometric targets. Where spatial techniques use a 3D grid in space directional techniques make use of a 2D grid of elements subtending finite solid angles mapped onto 2D surfaces. Examples of directional techniques are discussed in [Haines86], “Ray Coherence Theorum and Constant Time Ray Tracing Algorithm.” Ohta, et al., Computer Graphics 1987 (Proc. of CG International '87) (ed. T. L. Kunmi, pp. 303-314); and [Arvo87].
The technique described in [Haines86] uses a light buffer to reduce the number of objects tested for shadow ray intersection computation. The light buffer is a 2D grid mapped onto the surface of a direction cube surrounding a point light source. Each cell of the direction cube contains a near-to-far ordered list of the geometric targets visible within the solid angle subtended by the cell. To determine if a point is illuminated by the light or is occluded by another object, the shadow ray (originating at the point and directed at the light) is intersected with the surface of the direction cube and mapped into the 2D grid. The list of targets enumerated in the appropriate cell is then tested against the ray. If the ray intersects any target between the point and the light, then the search ends and the point is in shadow, otherwise the point is illuminated by the light. A similar approach known as First Hit Acceleration makes use of depth buffering scan conversion hardware to render from the camera's point of view, but instead of storing colors in the frame buffer, the first hit acceleration approach stores a pointer or reference to the nearest target along the trajectory of the ray passing through each pixel.
The procedure, referred to as 5D Ray Classification, described in the above-identified Arvo article transforms each ray into a 5D point (x,y,z,u,v), where (x,y,z) are the ray's origin and (u,v) are 2D coordinates mapped onto the surface of a direction cube derived from the ray's direction vector. The scene database is duplicated and sorted into six lists—one for each of the six dominant axes (+X, −X, +Y, −Y, +Z, −Z). During the rendering process the scene database is dynamically partitioned into parallelepiped subsets of 5D space (corresponding to beams in 3D space). When a ray is tested against the scene, it is “classified” (converted into a 5D point) and its dominant direction axis is computed from the sign and axis of the largest absolute valued component in the ray direction vector. A candidate list is selected which corresponds to the primary axis of the ray direction vector, and those targets within the candidate list which lie inside the parallelepiped are tested against the ray in approximately the same order that they would be encountered along the ray's trajectory. For this reason, Ray Classification supports an early exit so not all the targets need be tested when an intersection occurs near the ray origin.
Because directional techniques require multiple lists of target geometry they consume a large amount of space and are not particularly efficient with memory caching schemes.
SUMMARY OF THE INVENTION
An object of this invention is to provide an improved technique, for use in a computer graphics image generation system, to reduce the number of polygon intersection tests needed to test a ray against a set of polygons.
Another object of the present invention is to arrange a set of polygons, and to provide a simple procedure to arrange these polygons, in different groups according to the general orientations of the polygons.
A further object of this invention is to provide a compressed representation, and a procedure for computing this compressed representation, of the general direction of a ray or similarly oriented group of rays and the general direction of a polygon normal or a group of polygons with similarly oriented normals.
These and other objects are attained with a method and apparatus, in a computer graphics image generation system, for reducing the number of polygon intersection tests required to test a ray against a set of polygons. With this method, a multitude of polygons that represent images of object or parts of objects are identified, and these polygons are grouped into a plurality of groups on the basis of the general orientations of the polygons. Also, a ray is identified that represents a line of sight, and the general direction of the ray is compared with the general orientations of the polygons in the above-mentioned groups of polygons. On the basis of this comparison, selected groups of polygons are eliminated from further consideration. Polygons in other groups may be tested to determine if the ray intersects the polygons.
The preferred embodiment of the invention described herein in detail has a number of important features. These include:
(1) A compressed representation of the general direction of displacement of a 3D vector called the directional classification code and a method for computing it given a vector.
(2) A conservative but efficient technique for determining whether the dot product of two vectors of equal length will result in a positive or negative value by comparing their directional classification codes using boolean logic.
(3) A rendering preprocess in which a set of polygons in a common coordinate system are arranged into directionally classified polygon groups according to their directional classification codes.
(4) A method of sorting the polygons within a directionally classified polygon group in front to back order along a group unit normal vector.
(5) A method of reducing the number of ray-polygon intersection calculations performed by a ray tracer which uses the directional classification code, the group unit normal vector and directionally classified polygon groups.
Further benefits and advantages of the invention will become apparent from a consideration of the following detailed description, given with reference to the accompanying drawings, which specify and show preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a computer graphics system that may be used to embody the present invention.
FIG. 2 shows another computer graphics system that may also be used to embody this invention.
FIG. 3 illustrates the concept of backface culling in a computer graphics system.
FIG. 4 depicts the concept of camera coordinate backface culling employed in scan conversion rendering architectures.
FIG. 5 pictorially illustrates the problems ray tracing poses to the traditional backface culling problem.
FIG. 6 is a flow diagram showing steps used to classify various polygons into groups.
FIG. 7 is a flow diagram that outlines a procedure for determining which polygon groups need to be tested for ray intersection.
FIG. 8 shows a set of triangles with a similar orientation that have been placed in a target group.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Computer system 10 illustrated in FIG. 1 includes a bus 12 for communicating information, a processor 14 coupled with the bus for processing information, and a memory 16 such as a RAM that is coupled with the bus for storing information and instructions for the processor. System 10 further includes video display device 20 , such as a CRT raster scan device and a data storage device 22 , such as a magnetic disc, coupled with the bus 12 that is also used to store information and instructions.
Alternative computer systems having specifically designed graphics engines are well known in the art. Commonly, these alternative computer systems modify the system of FIG. 1 by incorporating a specialized graphics subsystem that includes a graphics processor, a dedicated frame buffer, often in the form of video DRAM, and a video display.
FIG. 2 shows an example of a computer system 30 having a graphics subsystem 32 . In this system 30 , input image data from the main processor 14 are communicated over bus 12 and bus 34 to the graphics processor 36 . This image data are typically in the form of graphics primitives such as lines, points, polygons or character strings. The graphics processor 36 receives that input image data from the main processor 14 and uses that data to create a complete image data set utilizing well known graphics techniques such as scan conversion, clipping, Gouraud shading and hidden surface algorithms.
The image data developed by the graphics processor 36 is stored in high performance memory 44 , which typically includes the frame buffer. Graphics processor 36 addresses the video ram 40 over the address bus 46 while supplying the video information over bus 50 . After an image has been generated, the contents frame buffer image data is read out to a digital to analog converter or transferred to another computer over a network or stored on hard disc. This image data may then be transmitted to a video display device 54 or to other raster scan display devices.
In the operation of system 30 , clipped polygon information, in the form of parameter values for each vertex of a polygon is typically received by the graphics processor 36 . Alternatively, that information could be calculated by the graphics processor. In either case, coordinate values for these polygon vertices are then converted by processor 36 , using well known transformation techniques, to the output device coordinate space at subpixel resolution. Then, the scan conversion and filling of the polygons occurs.
Many of these polygons do not actually appear in the video image because they are on the back sides of objects in that image. For instance, when the front side of a house is shown in the video image, the polygons used to construct the image of the back side of the house are not shown in the image on the display device 54 . In order to increase the rate at which the computer grapics system processes the relevent polygons, it is preferred to eliminate, or to cull, these backfacing polygons from the video processing procedure.
FIG. 3 depicts the fundamental concept of backface culling. An eye 60 is located at a point in space and is looking along a view vector indicated by the arrow 62 whose base is located at the pupil of the eye. The eye is looking at a cube 64 constructed out of a set of triangles. Two triangles have been highlighted and labeled 64 A and 64 B. A surface normal has been drawn for each of these triangles and has been labeled N a for the surface normal vector of triangle 64 A and N b for the surface normal vector of triangle 64 B. Triangle 64 A faces the camera and as such has the potential to be visible. Because triangle 64 B faces away from the camera, it cannot be seen and can be safely culled from further rendering processing.
FIG. 4 illustrates the concept of camera coordinate backface culling employed in scan conversion rendering architectures. All vertices and normal vectors are in a common coordinate system where the eye is at the origin of the coordinate system and the view vector is equal to the positive Z axis. In this approach, the process of determining back facing polygons consists of checking the sign of the Z component of each polygon's surface normal vector. If the surface normal vector's Z component is positive, then the polygon can be assumed to be backfacing. In this example, the Z component of vector N a is negative so triangle 64 A has the potential to be visible, but the Z component of vector N b is positive indicating that triangle 64 B is backfacing.
FIG. 5 depicts the problems ray tracing poses to the traditional backface culling problem. Note that in ray tracing, the origin of the coordinate system is no longer the camera position and that the positive Z axis is no longer the camera's line of sight. This drawing depicts the flight of two rays. The first 66 a is referred to as an eye ray for it originates at the center of projection of the camera (the eye) and travels through a pixel of the image plane. This first ray strikes the surface of a long rectangular box 70 behind cube 64 . The second ray 66 b is referred to as a reflection ray and is directed from the surface of the long rectangular box along an angle of reflection. Because reflection rays originate in places other than the camera and travel in directions other than the camera's line of sight, the previous generalizations of backface culling employed in scan converting rendering architectures do not apply in ray tracing rendering architectures.
The culling algorithm of this invention is based on the fundamental assertion that a single sided polygon facing east cannot be hit by a ray which is traveling east, regardless of the location of the polygon or the origin of the ray. Mathematically this can be expressed:
if N<dot product>D>0, then the ray cannot hit the polygon
Where:
N is the polygon geometric unit normal vector, and
D is the ray unit direction vector.
To compute the unit normal vector of a polygon and the dot product with the ray direction vector at the inner loop of a ray tracer, is computationally too expensive to provide a significant increase in performance. This cost can be reduced by computing the polygon normal as a preprocess and storing that normal with the polygon vertices. However, this requires considerably more storage and transfer bandwidth, plus the extra dot product is required at the inner loop of the ray tracer.
If the method described in Zhangh, et al., is employed then the costly process of computing the backfacing mask has to occur once for each ray. At best, either of those approaches only yields a linear increase in performance because each polygon must be explicitly fetched and tested, and it is more than likely that both approaches would actually slow down the renderer in a majority of the cases.
Instead, in the present invention polygons are grouped together based upon a directional classification code into directionally classified target groups, and then a directional classification code of the ray direction vector is tested against a directional classification code of a group header. If the test between the codes fails, then none of the triangles in the group needs to be fetched or tested. This procedure can eliminate thousands of polygons without explicitly fetching those polygons. Because of this, the procedure attains the sublinearity described in the Kumar article without requiring the exhaustive hierarchical search or spatial partitioning. Note that even more performance can be gained by buffering up and sorting rays into bundles (where each bundle contains hundreds or thousands of rays sharing the same directional classification code). In such a scenario, we can test the directional classification code of each bundle against the directional classification code of each directionally classified polygon group instead of testing each ray's directional classification code. In addition, this grouping can coexist within spatial subdivision cells or bounding volumes so it can work in concert with other acceleration methods.
Directional Classification Code
The approach of this invention is to compute the polygon normal as a preprocess, but instead of storing this polygon normal, the procedure of this invention stores a directional classification code which is a compressed representation of the orientation of the polygon's normal vector. The directional classification code retains enough information about the polygon orientation to categorically eliminate large numbers of potential ray intersection tests which have no chance of hitting the polygon. If every polygon and every ray have directional classification codes, then large numbers of ray intersection tests can be eliminated without requiring any floating-point computation in the inner loop of the renderer.
The first three bits of the directional classification code are the sign bits of the normal vector. The next six bits of this code are the relative magnitude bits for the X, Y, and Z axes. These bits indicate (for each axis) whether the axis in question is greater or lesser in absolute value than the other two axes. These bits are useful in identifying the major(largest) and minor(smallest) axes of a given vector. The major axis will have two of its relative magnitude bits set. A minor axis will have none of its relative magnitude bits set.
In certain circumstances, it may be necessary to handle polygons or rays which have not been directionally classified. In the preferred embodiment, such polygons are given a directional classification code of zero. The directional classification code of zero and any other directional classification code returns true. Any ray with a directional classification code of zero needs to be tested against any target regardless of its directional classification code. Any target with a directional classification code of zero needs to be tested against any ray regardless of its directional classification code.
Divining the Sign of the Dot Product
FIG. 3 demonstrates that the sign of the dot product between the view vector 62 and the triangle normal, either N A or N B , determines whether the triangle, either 64 A or 64 B, is facing away from the view vector. Generally, the dot product between a three dimensional polygon normal vector N and a three dimensional camera view vector V can be expressed mathematically:
N<dot product>V=(N.X * V.X)+(N.Y * V.Y)+(N.Z * V.Z)
Where:
N is the polygon normal vector, and
V is the camera view vector.
If the sign bits of the (X,Y,Z) components of vector N are the same as the sign bits of the (X,Y,Z) components of vector D, then the dot product will be positive, and the intersection test need not be performed. Henceforth, a reference to a “sign match” between two unit vectors expresses the fact that the X, Y, or Z component of the first vector has the same sign as the same component in the second vector.
The optimization in the previous paragraph (three sign bit matches) works well, but may cast too narrow a net to be highly effective alone. Using the relative magnitude bits, it is possible to eliminate more polygons using simple Boolean logic and the directional classification codes when less than three sign bit matches occur:
1. A positive dot product always results from two unit vectors sharing only two sign matches when the major axis of the first vector is matched in sign and axis to the major axis of the second vector.
2. A positive dot product always results from two unit vectors sharing only two sign matches when (i) the major axis of the first vector is matched in sign to a non-minor component of the second vector and (ii) the major axis of the second vector is matched in sign to a non-minor component of the first vector.
Directionally Classified Polygon Groups
With reference to FIG. 6, a set of polygons within a scene, bounding box, voxel grid, or BSP half-space can be organized into directionally classified polygon groups by computing the normal vector, as represented by step 102 and a corresponding directional classification code for each polygon, as represented by step 104 . A directionally classified target list is constructed where each node in the list includes a field for a directional classification code, a 3D vector, and a pointer to a linked list of triangles. Initially the list is a null list. As each polygon's directional classification code is computed, the directionally classified target list is searched, as represented by step 106 , to find a node with a matching directional classification code. If a corresponding node is found, then as represented by step 106 a , a new target list element is created and added to the node's target list and the polygon normal vector is added to the group normal vector in the node. If no such node is found, then, as represented by step 106 b , a new node is created and added to the directionally classified target list with said directional classification code, normal vector, and a pointer to a new target list element whose pointer references said triangle.
Front to Back Ordering
When all the polygons in the set have been classified and processed, each node in the directionally classified target list counts the number of polygons in its target list and divides its group normal vector by that number. This vector is then divided by its length to obtain a value referred to as the group unit normal vector. The node then computes and stores the minimum and maximum extent along the group unit normal vector of each triangle in its target list. To compute the extent of a vertex against a group unit normal vector, the procedure computes the dot product of the vertex position vector and the group unit normal vector The minimum and maximum extents of a triangle are calculated by computing the extent of each vertex of the triangle and evaluating the minimum and maximum extent values. The target list nodes can then be sorted according to their maximum extents in positive to negative order, which are stored as fields within the target list node. This has the effect of sorting the triangles in front to back order for a majority of the viewpoints from which the triangles are visible.
Accelerated Ray Tracing
With reference to FIG. 7, when a ray is to be tested against a directionally classified target list, a directional classification code is computed from the ray's direction vector, as represented by step 110 . Each node in the directionally classified target list contains a set of targets oriented in a common direction represented by the node's directional classification code. As represented by step 112 and 114 , the ray's directional classification code is tested against the directional classification codes of the nodes in the directionally classified target list using the criteria described above.
If the resulting comparison predicts a positive dot product, then all of the targets in the node's target list need not be fetched or tested against the ray because they are definitely backfacing, as represented by step 114 a . Otherwise, as represented by step 114 b , the targets in the list need to be tested against the ray.
This process continues, as represented by steps 116 , 116 a and 116 b of FIG. 7, until all the polygon groups have been tested. When this is done, the nearest encountered intersection is returned.
If a result of a directional classification test between a ray and a directionally classified triangle list is true, it means that it is possible for the ray to hit one or more of the polygons in the directionally classified triangle list. In most ray tracing applications, a given ray needs only to be tested against enough targets to establish the nearest visible target. Because directional classification codes guarantee certain properties among the polygons and rays which are tested against them, it is possible to sort the polygons of a directionally classified target group before rendering so they are tested in front to back order (most positive extent first, most negative extent last) and only test each ray against a fraction of the polygons in the directionally classified target list.
If the rays which are to be tested against the polygons in the directionally classified target list are sorted (most positive extent first, most negative extent last), then only the fraction of rays in the list which are in front of the polygon and have hit no other targets in front of the polygon actually get tested against the polygon. When the minimum extent of a ray is greater than (less negative than) the maximum extent of the polygon being tested, it can be swapped out of the list of rays being tested against that directional classification list and can be replaced by a ray whose minimum extent is less than (more negative than) the minimum extent of the polygon being tested. This ensures that the replacement ray could not have previously hit any of the polygons which had already been tested against the rays in the list.
With the preferred embodiment of the invention described herein in detail, before testing the ray against the contents of the node's target list, it is necessary to compute the extent of the ray's position vector along the group unit normal vector. This is computed as the dot product of the ray position vector and the group unit normal vector. This value will be stored with the ray as the ray's maximum extent along the group unit normal vector. If the ray has already intersected another target then the extent of the intersection point along the group unit normal vector needs to be computed and stored as the ray's minimum extent along the group unit normal vector. If a ray has not yet hit a target, then the minimum extent is assigned the value of negative infinity by default. When the minimum and maximum extents have been computed, the target list can be traversed.
The ray need not be tested against polygons whose minimum extent along the group unit normal vector is greater than the ray's maximum extent along the group unit normal vector because the ray originates behind the triangle and faces away from it. The ray need not be tested against polygons whose maximum extent along the group unit normal is less than the ray's minimum extent because the polygon lies beyond the polygon already intersected by the ray. Only targets whose minimum extent is less than the ray's maximum extent and whose maximum extent is greater then the ray's minimum extent need to be tested against the ray. If the ray intersects a target, then the intersection is retained and its extent along the group unit normal vector is computed. Subsequent targets are tested against the ray, replacing the intersection test with (and computing the extent of) any intersection which is closer to the ray's position vector. Intersection testing ceases when a prospective target has a maximum extent which is smaller than the extent of the nearest ray intersection. When testing the ray against multiple directionally classified target lists, it is important to retain the nearest intersection and recompute extent of the ray along each group unit normal vector. By skipping over triangles which lie behind the ray origin and providing an early exit for occluding intersection, the procedure further reduce the number of ray triangle intersections in dense triangle meshes.
FIG. 8 shows a set of triangles with similar orientation from two separate objects which have been placed in a directionally classified target group. Because these triangles have similar orientations, it is possible to test the group as a whole for backface culling instead of testing each individual triangle.
The method of this invention has been reduced to practice in Photon ray tracing workbench software in about one hundred lines of C++ code. In particular, a method has been added to a vector class called classify which returns an integer directional classification code. A new member has been added to the ray class which is called dccode which contains the directional classification code of the ray direction vector. This value is computed when the ray is created with the ray class constructor function.
Code has been added to a method function called TriangulateClippedPolygon, in a SEADS voxel class which computes each triangle's geometric normal vector and groups triangles together which have a common directional classification code. This function is called once during the scene assembly rendering preprocess.
A new target subclass, dctargetlist, has been added which has an integer member called dccode which represents a common classification code for all of the targets in the link list referenced by the targs member of the dctargetlist. A member function called intersectray checks the ray's dccode against the dctargetlist's dccode for the properties listed above; and depending upon the results of the test, this function either tests the ray against the list of targets or refers the ray to the next dctargetlist and returns it's results. This function is called during the inner loop of the renderer.
This algorithm has been further extended to reduce the number of intersection tests performed by the intersectray function. After the triangles are sorted into directionally classified groups, the process computes the average normal vector of all the triangles in each group (the group unit normal vector), stores this computed vector in the dctargetlist header, and computes and stores the minimum and maximum extent of each triangle along its group unit normal vector. The triangles can then be sorted according to their maximum extents in positive to negative order. This has the effect of sorting the triangles in front to back order for most vantage points from which they can be seen.
To compute the extent of a vector against a group unit normal vector, the process computes the dot product of the two vectors. The minimum and maximum extents of a triangle are calculated by computing the extent of each vertex of the triangle and evaluating the minimum and maximum extent values.
If a ray's directional classification code has satisfied the criteria described above and the ray is to be tested against the members of a directionally classified triangle list, then more efficiency can be gained by computing the extent of the ray origin vector along the group unit normal vector. The ray can skip over those triangles in the list whose minimum extent is larger than the ray's extent. Those triangles do not need to be fetched or tested against the ray because the ray originates behind them and is traveling away from them. The ray need not be tested against polygons whose maximum extent is smaller than the minimum extent if the ray because they lie beyond the nearest intersection already found by the ray. Only triangles whose minimum extent is less than the ray's maximum extent and whose maximum extent is less than the ray's minimum extent need to be tested against the ray.
If the ray intersects a triangle, then the intersection is retained and the extent of the intersection along the group unit normal vector is computed. Subsequent triangles are tested against the ray, replacing the intersection value with (and computing the extent of) any intersection which has a smaller parametric length along the ray. Intersection testing ceases between a ray and a directionally classified triangle list when a prospective triangle has a maximum extent which is smaller than the extent of the nearest ray intersection. When testing the ray against multiple directionally classified triangle lists, it is helpful to retain the nearest intersection and recompute its extent along each group unit normal vector. By skipping over triangles which lie behind the ray origin and providing an early exit for occluding intersection, the number of ray triangle intersections in dense triangle meshes can be further reduced.
While it is apparent that the invention herein disclosed is well calculated to fulfill the objects previously stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.
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A method and apparatus, in a computer graphics display system, for reducing the number of polygon intersection tests required to test a ray against a set of polygons. With this method, a multitude of polygons that represent images of object or parts of objects are identified, and these polygons are grouped into a plurality of groups on the basis of the general orientations of the polygons. Also, a ray is identified that represents a line of sight, and the general direction of the ray is compared with the general orientations of the polygons in the above-mentioned groups of polygons. On the basis of this comparison, selected groups of polygons are eliminated from further consideration. Polygons in other groups may be tested to determine if the ray intersects the polygons. The preferred embodiment of the invention described herein in detail has a number of important features. These include (1) a compressed representation of the general direction of displacement of a 3D vector called the directional classification code and a method for computing it given a vector, and (2) a conservative but efficient technique for determining whether the dot product of two vectors of equal length will result in a positive or negative value by comparing their directional classification codes using boolean logic.
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CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese application serial No. 2003-394869, filed on Nov. 26, 2003, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a magnesium alloy whose molten metal exhibits good fluidity. The magnesium alloy exhibits good creep properties. The magnesium alloy is particularly suitable for engine related parts.
[0004] 2. Related Art
[0005] Magnesium alloys have been utilized as structure materials or housings for automobiles or portable electronic devices because of their light weight and high specific strength. Parts of these alloys have been manufactured by die-casting or injection molding; as magnesium alloys the following are known.
(1) Mg—Al—Zn series such as ASTM: AZ91D (2) Mg—Al—Mn series such as ASTM: AM60B, AM50A (3) Mg—Al—Si series such as ASTM: AS41B (4) Mg—Al-rare earth element series such as ASTM: AE42
[0010] Among the alloys the (1) alloy is most widely used as casings for potable telephones and notebook type personal computers. Particularly, it is said that AZ91D has well balanced fluidity, mechanical strength and corrosion resistance. The alloy (2) has improved impact resistance, and alloys (3), (4) have improved mechanical strength such as creep characteristics.
[0011] Patent Document: Japanese Patent Laid-open 2001-158930
[0012] From the viewpoints of energy saving with light-weight of car bodies and recycling of the used products, a large expectation to magnesium alloys is concentrated in recent years. Application of magnesium alloys to engine parts is expected, accordingly. Among the alloy series, though AZ91D has relatively good fluidity, its creep strength is poor and hence application of the alloys to engine parts is not proper.
[0013] The AS41B or AE42 alloys with improved creep properties have poorer fluidity than the AZ91D alloys, resulting in a low molding yield.
[0014] The engine related parts include intake manifolds, cylinder head covers, oil pans, transmission cases, for example. The conventional magnesium alloys such as AZ91D, AM60B, which can be shaped by die-casting and injection molding, show poor heat resistance at high temperatures. For example, bolts for fixing the parts may be loosen. Thus, the magnesium alloys are not suitable for engine parts used at a temperature higher than 100° C.
[0015] Accordingly, magnesium alloys for engine parts should have good creep characteristics such as a small deformation, i.e. a small creep strain at high temperatures. Since the magnesium alloys of the present invention are better in creep characteristics than the conventional magnesium alloys, they can be used under high temperatures and high pressures. Further, the molten metal of the alloys has a good fluidity being almost equal to that of AZ91D, it is possible to produce mass production parts without or almost free from defects by die-casting or injection molding.
SUMMARY OF THE INVENTION
[0016] It is a subject of the present invention to provide magnesium alloys with good fluidity and creep toughness.
[0017] In one aspect of the present invention, a magnesium alloy according to the present invention consists essentially of 10 to 15% by weight of Al, 0.5 to 10% by weight of Sn, 0.1 to 3% by weight of Y, 0.1 to 1% by weight of Mn, the balance being Mg and inevitable impurities.
[0018] In another aspect of the present invention, a magnesium alloy consists essentially of 10 to 15% by weight of Al, 0.5 to 10% by weight of Sn, 0.1 to 3% by weight of Y, 0.1 to 1% by weight of Mn, 0.1 to 5% by weight of Zn, the balance being Mg and inevitable impurities.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a shape of a mold having a test piece for testing fluidity evaluation.
[0020] FIG. 2 is a graph showing the test result of fluidity.
[0021] FIG. 3 is a graph showing the creep test results.
[0022] FIG. 4 is a side view of a intake manifold.
[0023] FIG. 5 is a partial cross sectional view of a cylinder cover.
[0024] FIG. 6 is a perspective view of an oil pan.
DESCRIPTION OF THE INVENTION
[0025] Al lowers a melting point of magnesium alloys thereby to improve fluidity of the alloy. Al forms Mg—Al series compounds to improve strength at room temperature. If an amount of Al is less than 10% by weight, the fluidity is insufficient and the injection molding of the alloy becomes difficult. If an amount of Al content exceeds 15% by weight, a large amount of Mg—Al compound is formed to constitute a network so that the elongation of the alloy lowers.
[0026] Sn lowers a melting point of the alloy to improve fluidity of the alloy. If an amount of Sn is less than 0.5% by weight, the fluidity is insufficient so that casting of the alloy becomes difficult; if an amount of Sn is larger than, the effect of addition of Sn becomes saturated. In addition to that, the specific gravity of the alloy becomes large so that an advantage of light-weight of Mg alloys would be lost.
[0027] Y forms Al—Y compounds having relatively high melting points to improve the creep strength of the alloy. If an amount of Y less than 0.1% by weight, a sufficient creep strength would not be expected. On the other hand, if an amount of Y exceeds 3% by weight, a large amount of Al—Y compounds is formed thereby to increase a melting point of the alloy so that casting of the alloy becomes difficult. Further, since Y is an expensive element, a large amount of Y increases a cost of the alloy.
[0028] Mn forms compound with Al and Fe which causes corrosion of the magnesium alloys and improves corrosion resistance by trapping iron atoms in the compounds. If an amount of Mn is less than 0.1% by weight, the effect of corrosion resistance of the alloy is insufficient. If an amount of Mn exceeds 1% by weight, there is a tendency that an yield of melting of the alloy becomes worse. A further improvement of the corrosion resistance would not be expected if an excess amount of Mn is added. Since Mn has a large specific gravity, it may locally precipitate or precipitate in the bottom of the molten metal vessel.
[0029] Zn may be added in some cases. Zn may lower a melting point of the alloy to improve fluidity. If an amount of Zn exceeds 3% by weight, there is a tendency that casting crack may be generated.
[0030] The present invention provides magnesium alloys that have excellent fluidity and creep properties.
[0031] Other examples of the magnesium alloy compositions are shown in Table 1 below. In the Table 1, numerals represent % by weight.
TABLE 1 Al Y Mn Sn Zn Mg (1) 10 0.5 0.2 8 2 bal. (2) 15 3 0.8 3 0.1 bal. (3) 12 1 0.2 5 0.1 bal. (4) 15 2 0.8 1 0.5 bal. (5) 10 1 0.2 2 5 bal. (6) 12 0.8 0.2 5 0.5 bal.
[0032] Because of good creep strength and good fluidity, the magnesium alloys can preferably be applied to engine related parts such as intake manifolds shown in FIG. 4 . The intake manifold 1 comprises a collector 4 , blankets 3 and storage chamber 2 . A cylinder head covers shown in FIG. 5 . The cylinder head cover 6 having hollows 8 , 9 and an oil storage 15 confined by a rib 16 is fixed to a baffle plate 7 . An oil pan is shown in FIG. 6 . The oil pan P has a fixing flange 10 having fixing holes 3 and is fixed to a cylinder block. Since the above applications are well known in the art, detailed explanation is omitted to avoid redundancy. These parts are castings, which require good fluidity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Examples of the magnesium alloys according to the present invention will be explained. Magnesium alloy ingots whose compositions were adjusted to be ones shown in Table 1 were cut into alloy chips of 2 to 5 mm diameter (length; about 5 mm or less, diameter; about 3 mm or less) as a raw material of injection molding. The alloy No. 1 is a conventional material AZ91D. An injection molding machine whose a die clamping force is 75 tons was used. FIG. 1 shows a plane view of a test piece for fluidity evaluation. An injection speed was 1.0 m/sec, and A mold temperature was kept constant at 200° C. The injection temperature was properly controlled. The length of the test pieces injection-molded at different temperatures, the fluidity was evaluated as the length being from the gate to a position where a defect occurs. The results are shown in Table 2.
TABLE 2 Ai Y Mn Sn Zn No. 1 Comparison 9 — 0.2 — 0.8 No. 2 Comparison 12 — 0.2 5 0.7 No. 3 Example 11 1 0.2 5 — No. 4 Example 12 2 0.2 5 1 No. 5 Comparison 10 2 0.2 — — No. 6 Comparison 13 4 0.2 4 —
[0034] FIG. 2 is a graph showing the measurement results of fluidity of the alloys. The abscissa of FIG. 2 represents a cylinder temperature of injection mold and the ordinate represents a flow length. The alloy No. 3 exhibited a larger flow length and good fluidity than the alloy No. 1 did. The alloy No. 3 is capable of being injection-molded at a temperature lower than 20 to 30° C. than that of the alloy No. 1.
[0035] The same tests were carried out with respect to the alloy Nos. 2, 4, 5 and 6. The fluidity test results of the alloys No. 2, 4, 5 and 6 are shown n Table 2. The alloy Nos. 2, 4, 5 and 6 exhibited better fluidity than the alloy No. 1 (AZ91D). The alloy No. 6 whose content of Y is larger than the alloy of the present invention was hard to be injection-molded because of frequent metallurgical sticking to the injection-mold.
TABLE 3 No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 Fluidity Δ ⊚ ⊚ ◯ Δ X
⊚: A flow length of 330 mm or more and a temperature at which the maximum fluidity length is obtained is lower than 600° C. ∘: A flow length of 330 mm or more and a temperature at which the maximum fluidity length is obtained is 600 to 630° C. Δ: A flow length of 270 to 330 mm and a temperature at which the maximum fluidity length is obtained is 600 to 630° C. X: A flow length of less than 270 mm and a temperature at which the maximum fluidity length is obtained is 600 to 630° C.
[0040] The creep properties of the alloys No. 1 and alloy Nos. 2 to 4 that exhibited good fluidity were tested and evaluated. FIG. 3 shows the creep test results conducted at 150° C., 50 MPa.
[0041] The alloy No. 1 exhibited an strain as large as 5% around 50 hours. The alloy No. 2 exhibited a better property than the alloy No. 1, but it showed an strain larger than 4% around 250 hours; thus the alloy No. 2 cannot be applied as engine parts.
[0042] On the other hand, the alloy Nos. 3 and 4 of the present invention exhibited an strain of about 2% around 250 hours; the formers are remarkably better than the alloy Nos. 1 and 2.
[0043] As having been explained, the alloy Nos. 3 and 4 satisfy the fluidity and creep properties. The alloys to be applied to engine parts should have a sufficiently better fluidity than AZ91D and better creep characteristics than the NO. 2 alloy.
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A magnesium alloy consisting essentially of 10 to 15% by weight of Al, 0.5 to 10% by weight of Sn, 0.1 to 3% by weight of Y, and 0.1 to 1% by weight of Mn, the balance being Mg and inevitable impurities.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage of International Application No. PCT/EP2015/001282, filed on Jun. 25, 2015. The International Application claims the priority benefit of German Application No. 10 2014 015 852.7 filed on Oct. 25, 2014. Both the International Application and German Application are incorporated by reference herein in their entirety.
BACKGROUND
[0002] Described herein is a driver assistance system in a vehicle, that generates an intelligent refueling and/or recharging message.
[0003] Driver assistance systems are widespread in modern vehicles and assist the driver in controlling the vehicle. In addition, driver assistance systems include entertainment electronics systems and navigation systems. In general, driver assistance systems supply the driver with information about the state of the vehicle and the components thereof, that is to say also about the filling level of a vehicle fuel tank, and usually output a visual and/or acoustic signal when the filling level drops below a minimum filling quantity. This refueling message is retained for the time period until the vehicle has been refueled and the filling level has exceeded the minimum filling quantity. In vehicles with an electronic drive, these messages relate to the state of charge of the vehicle batteries or of vehicle accumulators.
[0004] German Patent Application No. 11 2009 000 257 T5 describes a system for determining a vehicle refueling strategy. The system includes one or more computers which are configured to select, for a specified route which is to be traveled along during a multi-day time period, (i) at least one day during the multi-day time period on which fuel is to be purchased, (ii) to select at least one refueling station along the route at which fuel is to be purchased for each selected day, and (iii) to determine a quantity of fuel which is to be purchased at each selected refueling station. The selection and the determination are based on present and predicted fuel prices for the multi-day time period, in order generally to minimize refueling costs for the specified route.
[0005] German Patent Application No. 10 2009 059 870 A1 describes a method for displaying information in a vehicle. According to the method a user input is registered, information is produced by using the user input, and an assigned display condition is defined. Subsequently, the information is stored with the assigned display condition, and the information is displayed if the display condition which is defined by the user is satisfied. In addition, a device for displaying information in a vehicle is described, the device including an input device for inputting information and assigned display conditions, a memory unit for storing the specified information with the assigned display conditions, a display surface, and a control device which is coupled to the memory unit of the display surface and with which the display on the display surface can be controlled.
[0006] German Patent Application No. 10 2012 219 929 A1 describes a vehicle assistance device having a control apparatus for generating data which provides recommendations for action for a vehicle occupant, a display device for displaying the recommendations as a function of the data generated by the control apparatus, an identification apparatus for identifying the vehicle occupant, a memory apparatus having a first memory for storing a first parameter which defines a state, and a second and third parameter assigned to the first parameter. The second parameter characterizes the vehicle occupant, and third parameter specifies a mode of behavior of the vehicle occupant in the state. The control apparatus is designed to determine whether the state which is stored in the first memory is present and to generate the data for display on the display apparatus as a function of the third parameter which is assigned to the first parameter, if the control apparatus detects the state which is characterized by the first parameter, and the vehicle occupant which is identified by the identification apparatus corresponds to the vehicle occupant which is characterized by the second parameter.
[0007] A disadvantage with the known systems with respect to a refueling message is that the refueling message is triggered exclusively when the filling level drops below a minimum filling quantity of the vehicle fuel tank and is retained until the vehicle is refueled. Destinations and driving situations as well as personal stipulations of the driver are not taken into account.
SUMMARY
[0008] Accordingly, an aspect of the driver assistance system described herein is to make available a possible way of also taking into account destinations, driving situations and/or personal stipulations of the driver when outputting refueling messages.
[0009] This may be achieved by the driver assistance system described herein, and by a corresponding method implemented by the driver assistance system. Further refinements of the driver assistance system can be found in the figures and the description herein.
[0010] According to a vehicle assistance system described herein, an intelligent refueling message is generated and informs the driver as to whether destinations have been reached yet or whether there is a preferred refueling possibility in the immediate surroundings. In the following statements relating to the description, the term “refueling message” does not refer exclusively to the filling level of a liquid fuel, such as gasoline or diesel in a vehicle fuel tank in the case of a motor vehicle with an internal combustion engine, but explicitly also to a state of charge of a vehicle battery and/or vehicle accumulator in the case of a vehicle with an electric drive. In addition, the term “refueling message” also refers to a gas fuel tank system in the case of a vehicle with a gas drive.
[0011] The driver assistance system described herein has a display unit and an evaluation unit for generating and for displaying a refueling message. The refueling message is generated in dependence on and independently of a fuel tank filling level and can be displayed for a time period which is to be predefined. The evaluation unit is configured here to check for the presence of conditions which are to be predefined, and given the presence of at least one condition, to generate on the basis thereof a refueling message and to output the refueling message via the display unit for the predefined time period.
[0012] In one possible refinement, the conditions which are to be predefined take into account, for example, the possibility of reaching current and/or future destinations, an instantaneous driving situation, a number of persons in the vehicle or personal stipulations of the driver.
[0013] In a further refinement of the driver assistance system described herein, the driver assistance system has an input unit via which the personal stipulations of the driver are to be input.
[0014] The instantaneous driving situation is generally derived from data which is determined by one or more driver assistance system surroundings sensors and which is made available to the evaluation unit. The conditions to be checked by the evaluation unit, for example may be checked at predefinable time intervals. For example, the conditions to be checked by the evaluation unit may be checked at, if appropriate, regular, time intervals. The conditions to be checked by the evaluation unit do not all have to be input by, for example, a driver via the input unit but instead can also be learnt by the driver assistance system by using a characteristic behavior of the driver.
[0015] A refueling message which is to be output can occur here acoustically, graphically, visually, by vibrations and/or haptically.
[0016] The “instantaneous driving situation” can be determined, for example, by using the driver assistance system surroundings sensors which are referred to and can be compared with “driving situations” which are stored in the driver assistance system, e.g., in a corresponding memory medium. When there is correspondence with one of these stored “driving situations”, a condition is satisfied which causes an individual refueling message to be generated and output via the display unit, or is intentionally not actually output, such as, for example, in a critical driving situation.
[0017] A number of persons in the vehicle can be determined, for example, by using weight sensors which are integrated into respective seats of the vehicle. For each number of persons it is possible to store a corresponding individual refueling message which is correspondingly output when there is a specific number of occupants present. Generally, a plurality of facts or influencing factors are linked in combination to a refueling message as a condition for the display thereof. In this manner, a specific distance to the destination at which a refueling message is output can be linked to a respective number of vehicle occupants. This means that given a defined number X 1 of vehicle occupants at a specific distance Y 1 , stored for this number X 1 , from the destination one refueling message is issued, while given a different number X 2 of vehicle occupants, where possible at a different distance Y 2 from the destination, a possibly different refueling message is issued.
[0018] In addition, in one possible refinement the refueling messages are displayed in a navigation system of the vehicle and for example may contain an indication of distance from the nearest refueling station as well as the associated price information for the required fuel.
[0019] If a critical fuel tank filling level is reached, according to one possible refinement of the driver assistance system described herein a refueling message which is generated and output or displayed has to be confirmed by the driver.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] These and other aspects and advantages will become more apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction
[0000] with reference to the drawings, of which:
[0021] FIG. 1 is a schematic illustration of a vehicle cockpit with components of an embodiment of the driver assistance system described herein, and
[0022] FIG. 2 is an example of a navigation screen as part of the embodiment of the driver assistance system from FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Reference will now be made in detail to the example embodiments which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0024] Further advantages and refinements can be found in the description and the accompanying drawings.
[0025] Of course, the features which are described above and which are still to be explained below can be used not only in the respectively specified combination but also in other combinations or alone without departing from the scope of the disclosure.
[0026] A schematic illustration provided in FIG. 1 illustrates a vehicle cockpit with components of a driver assistance system. The driver assistance system has a display unit 12 . The display unit 12 can be here a screen as part of a navigation system. An evaluation unit 16 , which is configured to check conditions which are to be predefined is also indicated. An individual refueling message 18 may be generated on the basis of the check and when at least one condition is satisfied. This refueling message 18 can be output to a driver via, for example, the display unit 12 .
[0027] Facts and influencing factors which are taken into account for the conditions and therefore also for their evaluation can include, for example, future destinations. For example, a condition can be stored that a refueling message is to be generated if the distance which can be covered with the fuel which is still present in a fuel tank of the vehicle is less than a future route, stored in the navigation system of the vehicle, to a destination. If either the driver assistance system or the evaluation unit 16 detects that a future destination is reached only with a refueling stop which is to be scheduled, the evaluation unit 16 generates a refueling message 18 which informs the driver about this. The message is also generated when, for example, the fuel tank filling level has not yet dropped below a minimum filling quantity of a vehicle fuel tank. However, the method of outputting differs depending on how much fuel is still present in the vehicle fuel tank. Initially, a refueling message which states that it is necessary to refuel during the journey is, for example, output only temporarily at time intervals, for example by including a short text message or a symbol which appears temporarily on a display of the display unit. If the fuel in the vehicle fuel tank decreases, the refueling message is, for example, supported by an acoustic signal and/or refueling stations in the surroundings are displayed on a map in the navigation menu, as is outlined, for example, in FIG. 2 . In addition, a constant display of the refueling message may then also occur.
[0028] A further stored condition can take into account an instantaneous driving situation. For example, a refueling message is not to be output during a critical driving situation. By using sensors, the driver assistance system can derive a critical driving situation, for example by using a bend profile of the section of road, a distance from vehicles traveling ahead and/or behind, the velocity or how firmly the steering wheel is being gripped. If the system detects that such a critical driving situation is present and if the fuel tank filling level reaches a point at which in a normal situation a refueling message would be generated, a refueling message 18 remains suppressed during a critical driving situation and is not output until after the situation has eased.
[0029] It is also conceivable that a number of persons in the vehicle is taken into account for one of the conditions. The corresponding condition can be, for example, that if just one person is located in the vehicle, specifically the driver, a generated refueling message which is to be output is supported by a corresponding acoustic indication and/or a voice output. If the system detects that just one person, specifically the driver, is located in the vehicle, the system assists a generated refueling message 18 which is to be output by using an additional voice output 20 and/or a corresponding acoustic indication.
[0030] Personal stipulations of the driver can also be taken into account. Personal stipulations of the driver can be transferred, for example, via an input unit 14 to the driver assistance system or can be learnt by using repeated characteristic behavior of the driver assistance system. The personal stipulations include, for example, price ranges within which the driver would preferably like to refuel the vehicle. If the driver assistance system detects, via a mobile data link, that a refueling station in the surrounding area offers fuel in this price range, a refueling message 18 can be generated without refueling being absolutely necessary. Refueling messages 18 can also be provided with a refueling suggestion with prices. Refueling suggestions can concentrate on brands which are preferred by the driver and can contain information about prices and a possible deviation from the planned route. When refueling stations are displayed on a navigation screen, preferred brands can be emphasized and other non-preferred brands can be displayed in a less pronounced color scheme.
[0031] Further conditions are conceivable and do not depart from the scope of the disclosure.
[0032] In a further refinement it is conceivable for refueling messages 18 to be output by using various options. For example, an acoustic tone 20 , which signals the need for refueling to the driver, is conceivable. Likewise, the refueling message can include a visual signal 22 in that, for example, a light lights up in the display unit. Graphic messages, for example in the screen of a navigation system, are also conceivable. If the remaining quantity in the vehicle fuel tank is critical, a vibration 24 , for example of a steering wheel, can also occur in order to alert the driver to the situation. A refueling message 18 can also be output in a combination of the specified options.
[0033] If the driver assistance system detects, after the starting of the vehicle, that the vehicle has to be refueled and if the remaining range is small, a refueling message can be issued which the driver has to confirm.
[0034] A description has been provided with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69 USPQ2d 1865 (Fed. Cir. 2004).
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A motor vehicle includes a driver assistance system having a display unit and an evaluation unit for generating and displaying a refueling and/or recharging message which is generated in dependence on and independently of a fuel tank filling level or a state of charge of a battery and can be displayed for a defined time period. The evaluation unit is configured to check for the presence of conditions which are to be predefined, and given the presence of at least one condition, to generate a refueling and/or recharging message and to output the refueling and/or recharging message via the display unit.
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This application is a division of application Ser. No. 758,696, filed Sept. 12, 1991, now U.S. Pat. No. 5,204,347, which, in turn, is a division of application Ser. No. 420,817 filed Oct. 12, 1989, now U.S. Pat. No. 5,077,292 issued Dec. 31, 1991.
BACKGROUND OF THE INVENTION
The present invention relates to novel substituted derivatives of quinoxaline. More particularly, the invention relates to such derivatives which are useful as therapeutic agents, for example, to effect reduction in intraocular pressure, to increase renal fluid flow and to effect an alteration in the rate of fluid transport in the gastrointestinal tract.
Various quinoxaline derivatives have been suggested as therapeutic agents. For example, Danielewicz, et al U.S. Pat. No. 3,890,319 discloses compounds as regulators of the cardiovascular system which have the following formula: ##STR2## where the 2-imidazolin-2-ylamino group may be in any of the 5-, 6-, 7- or 8- position of the quinoxaline nucleus; X, Y and Z may be in any of the remaining 5-, 6-, 7- or 8- positions and may be selected from hydrogen, halogen, lower alkyl, lower alkoxy or trifluoromethyl; and R is an optional substituent in either the 2- or 3- position of the quinoxaline nucleus and may be hydrogen, lower alkyl or lower alkoxy.
SUMMARY OF THE INVENTION
The novel compounds of the present invention are those having the formula: ##STR3## and pharmaceutically acceptable acid addition salts thereof, wherein R 1 and R 4 are independently selected from the group consisting of H and alkyl radicals containing 1 to 4 carbon atoms, R 2 and R 3 are independently selected from the group consisting of H, O, and alkyl radicals containing 1 to 4 carbon atoms, the 2-imidazolin-2-ylamino group may be in any of the 5-, 6-, 7- or 8- positions, preferably in the 6-position, of the quinoxaline nucleus, and R 5 , R 6 and R 7 each is located in one of the remaining 5-, 6-, 7- or 8- positions of the quinoxaline nucleus and is independently selected from the group consisting of Cl, Br, H and alkyl radicals containing 1 to 3 carbon atoms.
Particularly useful compounds are those in which R 1 and R 4 are H, R 2 and R 3 are independently selected from the group consisting of H and alkyl radicals containing 1 to 4 carbon atoms, the 2-imidazolin-2-ylamino group is in the 6- position of the quinoxaline nucleus, R 5 is selected from the group consisting of Cl, Br and alkyl radicals containing 1 to 3 carbon atoms, more preferably Br, and is in the 5- position of the quinoxaline nucleus, and R 6 and R 7 are H.
Pharmaceutically acceptable acid addition salts of the compounds of the invention are those formed from acids which form non-toxic addition salts containing pharmaceutically acceptable anions, such as the hydrochloride, hydrobromide, hydroiodide, sulphate or bisulfate, phosphate or acid phosphate, acetate, maleate, fumarate, oxalate, lactate, tartrate, citrate, gluconate, saccharate and p-toluene sulphonate salts.
The present compounds provide one or more therapeutic effects, e.g., in mammals. Thus, these compounds are useful in a method for treating a mammal in which one or more of these compounds are administered to a mammal in an amount sufficient to provide the desired therapeutic effect in the mammal. Among the desired therapeutic effects provided by the present compounds include altering the rate of fluid transport in the gastrointestinal tract of a mammal; reducing or maintaining the intraocular pressure in at least one eye of a mammal; and increasing the renal fluid flow in-at least one kidney of a mammal.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of the present invention, i.e., 2-imidazolin-2-ylamino tetrahydroquinoxalines, are as described above. All stereoisomers, tautomers and mixtures thereof which comply with the constraints of one or more formulae of the present compounds are included within the scope of the present invention. For example, both tautomers ##STR4## are within the scope of the present invention.
The present compounds may be prepared in a manner analogous to the procedures described in Danielewicz, et al U.S. Pat. No. 3,890,319 for the production of the quinoxaline derivatives therein. This patent is hereby incorporated in its entirety by reference herein. Once a 2-imidazolin-2-ylamino quinoxaline intermediate corresponding to the compound described in Danielewicz, et al U.S. Pat. No. 3,890,319 is obtained, this 2-imidazolin-2-ylamino quinoxaline intermediate is hydrogenated to saturate any unsaturation at the 1-, 2-, 3-, and 4- positions of the quinoxaline nucleus.
Briefly, the 2-imidazolin-2-ylamino quinoxaline intermediates may be prepared by (1) reaction of the appropriate amino-quinoxaline with thiophosgene to form the corresponding isothiocyanate; and (2) reacting this isothiocyanate with excess ethylene diamine to form the corresponding beta-aminoethyl-thioureidoquinoxaline, which is then cyclized to the corresponding intermediate. Alternately, such intermediates can be prepared by (1) reacting the corresponding aminoquinoxaline with benzoyl isothiocyanate to form the corresponding N-benzoyl thioureido compound, followed by hydrolysis to the thioureido compound, or reaction of the aminoquinoxaline with ammonium thiocyanate to form the thioureido compound directly; (2) methylation to form the S-methyl deviation of the thioureido compound; and (3) reaction with ethylene diamine to form the intermediate.
The 2-imidazolin-2-ylamino quinoxaline intermediate is then reacted to saturate any unsaturation at the 1-, 2-, 3-, and 4- positions of the quinoxaline nucleus. For compounds in which R 1 , R 2 , R 3 and R 4 are all to be H, the intermediate may be hydrogenated. This hydrogenation preferably occurs with the intermediate dissolved in a liquid, e.g., a lower alcohol such as methanol, ethanol or the like. A catalyst effective to promote the hydrogenation is preferably present. Examples of such catalysts include the platinum group metals, in particular platinum, platinum group metal compounds, such as platinum oxide, and mixtures thereof. Hydrogen, e.g., free molecular hydrogen, is present in an amount at least sufficient to provide the desired saturation, preferably in an amount in excess of that required to provide the desired saturation, of the intermediate. The temperature and pressure at which the hydrogenation occurs are preferably selected to maintain the intermediate and final product substantially in the liquid phase. Temperatures in the range of about 10° C. to about 1OO° C. and pressures in the range of about 0.5 atmospheres to about 5 atmospheres often provide acceptable results. These conditions are maintained for a time sufficient to provide the desired hydrogenation reaction. This period of time is often in the range of about 1 minute to about 2 hours. The final 2-imidazolin-2-ylamino tetrahydroquinoxaline is separated from the hydrogenation reaction mixture and recovered, e.g., using conventional techniques.
For compounds in which R 1 , R 2 , R 3 and R 4 are all to be H and for compounds in which R 1 and R 4 are to be H and R 2 and/or R 3 are to be alkyl, the intermediate may be reacted with a suitable hydride reducing agent. This reaction preferably occurs with the intermediate and the hydride reducing agent dissolved in a liquid. Any suitable hydride reducing agent may be employed. Examples of useful hydride reducing agents include Na BH 4 , NaCNBH 4 , LiAlH 4 and the like. The amount of hydride reducing agent used should be sufficient to saturate all the unsaturation present at the 1-, 2-, 3- and 4- positions of the intermediate. Excess hydride reducing agent may be employed provided that no deterioration of the final tetrahydroquinoxaline product results. The liquid employed should be such as to act as an effective solvent for the intermediate and the hydride reducing agent, and may also function to facilitate, e.g., activate, the reaction between the intermediate and hydride reducing agent. Examples of useful liquids include acetic acid, trifluoroacetic acid, tetrahydrofuran, diethyl ether and the like. The liquid employed is preferably selected so as to avoid excess hydride reducing agent reactivity. For example, where LiAlH 4 is used as the hydride reducing agent, the liquid is preferably tetrahydrofuran, diethyl ether and the like. One or more co-solvents, e.g., lower alcohols, may also be used. The temperature and pressures at which the reaction occurs are preferably selected to maintain the intermediate and final product in the liquid phase. Temperatures in the range of about 0° C. to about 50° C. and pressure in the range of about 0.5 atmospheres to about 2 atmospheres often provide acceptable results. Reaction time is chosen to allow the desired reaction to occur, and is often in the range of about one minute to about one hour. The final 2-imidazolin-2-ylamino tetraquinoxaline is separated from the reactive mixture and recovered, e.g., using conventional techniques, such as evaporation, deactivation of the excess hydride reducing agent, extraction and chromatographic separation.
For compounds in which R 1 and/or R 4 are to be alkyl, the intermediate (having no substituents corresponding to R 1 and R 4 ) may be reacted with a suitable hydride reducing agent in the presence of a selected aldehyde or aldehydes. The aldehyde or aldehydes used are selected based on the specific R 1 and/or R 4 alkyl group or groups desired. For example, if R 1 and/or R 4 is to be methyl, formaldehyde is used, if R 1 and/or R 4 is to be ethyl, acetaldehyde is used, etc. The reaction conditions used are similar to those described in the immediately preceding paragraph except that the reaction time is often in the range of about 1 hour to about 24 hours. The amount of aldehyde used may vary depending on the final compound desired. A mixture of final compounds, i.e., a compound in which both R 1 and R 4 are alkyl mixed with compounds in which only one of R 1 or R 4 is alkyl, may be produced by the reaction. One or more individual tetrahydroquinoxalines of the present invention can be separated and recovered from this mixture, e.g., using conventional techniques.
The present 2- imidazolin-2-ylamino tetrahydroquinoxalines are useful to provide one or more desired therapeutic effects in a mammal. Among the desired therapeutic effects are an alteration, preferably a decrease, in the rate of fluid transport in the gastrointestinal tract of a mammal, a reduction in or maintenance of the intraocular pressure in at least one eye of a mammal; and an increase in the renal fluid flow in at least one kidney of a mammal. Thus, for example, the present compounds may be effective as an anti-diarrhea agent, a medication for use in the treatment or management of glaucoma, and/or a medication for use in the treatment or management of kidney disease. One important feature of many of the present compounds is that the desired therapeutic effect is achieved with reduced side effects, in particular with reduced effects on the blood pressure of the mammal to which the present compound is administered.
Any suitable method of administering the present compound or compounds to the mammal to be treated may be used. The particular method of administration chosen is preferably one which allows the present compound or compounds to have the desired therapeutic effect in an effective manner, e.g., low medication concentration and low incidence of side effects. In many applications, the present compound or compounds are administered to a mammal in a manner substantially similar to that used to administer alpha agonists, in particular alpha 2 agonists, to obtain the same or a similar therapeutic effect.
The present compound or compounds may be included in a medication composition together with one or more other components to provide a medication composition which can be effectively administered. Such other components, e.g., carriers, anti-oxidants, bulking agents and the like, may be chosen from those materials which are conventional and well known in the art, e.g., as being included in medication compositions with alpha 2 agonists.
The present compounds are often administered to the eye of a mammal to reduce or maintain intraocular pressure in the form of a mixture with an ophthalmically acceptable carrier. Any suitable, e.g., conventional, ophthalmically acceptable carrier may be employed. Such a carrier is ophthalmically acceptable if it has substantially no long term or permanent detrimental effect on the eye to which it is administered. Examples of ophthalmically acceptable carriers include water, in particular distilled water, saline and the like aqueous media. The present compounds are preferably administered to the eye as a liquid mixture with the carrier. The compounds are more preferably soluble in the carrier so that the compounds are administered to the eye in the form of a solution.
When an ophthalmically acceptable carrier is employed, it is preferred that the mixture contain one or more of the present compounds in an amount in the range of about 0.0001% to about 1%, more preferably about 0.05% to about 0.5%, W/V.
Any method of administering drugs directly to a mammalian eye may be employed to provide the present compound or compounds to the eye to be treated. By the term "administering directly" is meant to exclude those general systemic drug administration modes, e.g., injection directly into the patients blood vessels, oral administration and the like, which result in the compound or compounds being systemically available. The primary effect on the mammal resulting from the direct administering of the present compound or compounds to the mammal's eye is preferably a reduction in intraocular pressure. More preferably, the present compound or compounds are applied topically to the eye or are injected directly into the eye. Particularly useful results are obtained when the compound or compounds are applied topically to the eye.
Topical ophthalmic preparations, for example ocular drops, gels or creams, are preferred because of ease of application, ease of dose delivery, and fewer systemic side effects. An exemplary topical ophthalmic formulation is shown below in Table I. The abbreviation q.s. means a quantity sufficient to effect the result or to make volume.
TABLE I______________________________________Ingredient Amount(% W/V)______________________________________(2-Imidazolin-2-ylamino) about 0.0001 to about 1.0tetrahydroquinoxalinePreservative 0-0.10Vehicle 0-40Tonicity Adjustor 1-10Buffer 0.01-10pH Adjustor q.s. pH 4.5-7.5antioxidant as neededPurified Water as needed to make 100%______________________________________
Various preservatives may be used in the ophthalmic preparation described in Table I above. Preferred preservatives include, but are not limited to, benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetate, and phenylmercuric nitrate. Likewise, various preferred vehicles may be used in such ophthalmic preparation. These vehicles include, but are not limited to, polyvinyl alcohol, povidone, hydroxypropyl methyl cellulose, poloxamers, carboxymethyl cellulose, hydroxyethyl cellulose, and purified water.
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.
Various buffers and means for adjusting pH may be used so long as the resulting preparation is ophthalmically acceptable. Accordingly, buffers include but are not limited to, acetate buffers, citrate buffers, phosphate buffers, and borate buffers. Acids or bases may be used to adjust the pH of these formulations as needed.
In a similar vein, ophthalmically acceptable antioxidants include, but are not limited to, sodium metabisulfite, sodium thiosulfate, acetycysteine, butylated hydroxyanisole, and butylated hydroxytoluene.
Other excipient components which may be included in the exemplary ophthalmic preparation described in Table I are chelating agents which may be added as needed. The preferred chelating agent is edetate disodium, although other chelating agents may also be used in place of or in conjunction with it.
The following non-limiting examples illustrate certain aspects of the present invention.
EXAMPLE 1
Preparation of 5-Bromo-6-(2-imidazolin-2-ylamino)-1,2,3,4-tetrahydroquinoxaline
1,2,4-Triaminobenzene dihydrochloride
To a suspension of 4-nitrophenylenediamine (Aldrich, 10 g, 65.3 mmol) in absolute ethanol (240 ml) was added 600 mg of 10% by weight palladium on charcoal catalyst. The container including the suspension was evacuated and filled with hydrogen three times and the suspension was hydrogenated at 18 psi until hydrogen uptake ceased. The reaction was slightly exothermic and one refill of hydrogen was required. The resulting light yellow solution, which darkens rapidly on contact with air, was filtered and concentrated to about 150 ml. Concentrated hydrochloric acid (12 ml) was added and the solid formed was filtered off. After drying in vacuo overnight, 12 g (a yield of 93%) of purple solid was obtained, m.p. 224-5° C. Using various analytical procedures, this solid was determined to be 1,2,4-triaminobenzene dihydrochloride.
6-Aminoquinoxaline
Glyoxal sodium bisulfite adduct (Aldrich, 14.3 g, 50 mmol) was added in small portions to a solution of 1,2,4-triaminobenzene dihydrochloride (9.8 g, 50 mmol) in 200 ml of 10% by weight sodium carbonate in water. The reaction mixture was heated to 100° C. for two hours and then cooled to 0° C. The crystals formed were filtered off and dried in vacuo to give a crude yield of 7.06 g (a yield of 97%) of brown crystals. Recrystallization from benzene gave 6.32 g (a yield of 87%) yellow crystals, m.p. 157-8° C. Using various analytical procedures, these yellow crystals were determined to be 6-aminoquinoxaline.
6-Amino-5-bromoquinoxaline hydrobromide
6-Aminoquinoxaline (2.08 g, 14.4 mmol) was dissolved in 11.5 ml glacial acetic acid. The solution was cooled in water while a solution of bromine (0.74 ml, 2.3 g, 14.4 mmol) in 1.5 ml glacial acetic acid was added slowly over 15 min. After stirring for an additional 30 min, the orange red solid formed was filtered off and washed thoroughly with dry ether. The solid was dried in vacuo overnight to yield 4.44 g crude product (a yield of 100%). The compound, 6-amino-5-bromoquinoxaline hydrobromide, had no definite melting point. A phase change (from fine powder to red crystals) was noticed at about 220° C. Decomposition was observed at about 245° C. It was used directly for the next step.
6-Amino-5-Bromoquinoxaline
The crude 6-amino-5-bromoquinoxaline from above was dissolved in water and saturated sodium bisulfite solution was added until the resulting solution tested negative with starch-iodide paper. The solution was then basified with 2N sodium hydroxide and extracted thoroughly with ethyl acetate. The organic extract was dried over magnesium sulfate and concentrated under reduced pressure to give the free base. The crude product was recrystallized from boiling benzene to give yellow crystals, m.p. 155-6° C. Using various analytical procedures, the yellow crystals were determined to be 6-amino-bromoquinoxaline. The yield was 82%.
5-Bromo-6-isothiocyanatoquinoxaline
The crude hydrobromide product previously noted (4.27 g, 14.0 mmol) was dissolved in 60 ml of water and thiophosgene (Aldrich, 1.28 ml, 16.8 mmol) was added in small portions with vigorous stirring. After 2 hours, the red color of the solution was discharged. The solid formed was filtered off and washed thoroughly with water. After drying in vacuo at 25° C., 3.38 g (a yield of 90%) of brick red crystals was obtained, m.p. 157-8° C. A portion of this material was further purified by column chromatography to give white crystals, m.p. 157-8° C. Using various analytical procedures, these crystals were determined to be 5-bromo-6-isothiocyanatoquinoxaline.
5-Bromo-6(-N-(2-aminoethyl)thioureido)quinoxaline
A solution of the isothiocyanate (3.25 g, 12.2 mmol) in 145 ml benzene was added to a solution of ethylenediamine (Aldrich, 5.43 g, 90.0 mmol) in 18 ml benzene at 25° C. over 2 hours. After stirring for a further 30 min., the supernatant was poured off. The oil which remained was washed by swirling with dry ether three times and used directly for the next step.
A portion of this product was further purified by column chromatography (SiO 2 , CHCl3 ) for characterization. A white solid was recovered which decomposed at 175° C. with gas evolution (puffing). This white solid was determined to be 5-bromo-6(-N-2-(aminoethyl)thioureido) quinoxaline.
5-Bromo-6-(2-imidazolin-2-ylamino)quinoxaline
The crude product from above was dissolved in 100 ml dry methanol and the brown solution was refluxed for 19 hours until hydrogen sulfide gas was no longer evolved. The mixture was cooled to room temperature and concentrated to about 50 ml. The yellow solid was filtered off and dried in vacuo; weight 2.52 g (a yield of 70%), mp 242-4° C.
As the crude product was insoluble in most common organic solvents, initial purification was achieved by an acid-base extraction procedure. 23 g of the crude product was dissolved in 100 ml 0.5N hydrochloric acid. The turbid yellow solution was filtered to give a clear orange yellow solution which was extracted twice with ethyl acetate (2 ×10 ml). The aqueous phase was cooled to 0° C. and basified with 6N sodium hydroxide, keeping the temperature of the solution below 15° C. at all times. The yellow solid which precipitated was filtered off and washed thoroughly with water until the washings were neutral to pH paper. The solid was dried overnight in vacuo to give 1.97 g yellow solid, m.p. 249-50° C. The recovery was about 88%.
Further purification was achieved by recrystallization as described below. The partially purified product from above was dissolved in N, N-dimethylformamide (about 17 ml/g) at 1OO° C. with vigorous stirring. The solution was filtered hot and set aside to cool overnight. The bright yellow crystals were collected by filtration, m.p. 252-3° C. Recovery was from 65-77%. Using various analytical procedures, the bright yellow solid was determined to be 5-bromo-6-(2-imidazolin-2-ylamino) quinoxaline.
5-Bromo-6-(2-imidazolin-2-ylamino)-1,2,3,4-tetrahydroquinoxaline
A thick-walled Parr hydrogenation flask was charged with 5-Bromo-6-(2-imidazolin-2-ylamino)quinoxaline (950 mg, 3.23 mmol), platinum oxide (95 mg) and 20 ml of methanol. The contents of the flask were contacted with hydrogen at 15 psi for 15 minutes. The resulting solution was filtered through acid washed silicon dioxide, followed by evaporation of solvent. The resulting tan solid was chromatographed (SiO 2 ; 80/20 CHCl 3 /CH 3 OH saturated with NH 3 (g)) to yield 820 mg (a yield of 86%) of an off white solid, mp 218-220° C. Using various analytical procedures, this off white solid was determined to be 5-bromo-6-(2-imidazolin-2-ylamino)-1,2,3,4-tetrahydroquinoxaline.
EXAMPLE 2
Preparation of (±)2-Methyl-5-bromo-6 -(2-imidazolin-2-ylamino)-1,2,3,4-tetrahydroquinoxaline
2-Methyl-6-nitroquinoxaline
A solution of pyruvic aldehyde (Aldrich, 40% solution in H 2 O, 11.8 g, 65.3 mmol) was added dropwise to a solution of 4-nitro-1,2-phenylenediamine (Aldrich, 10 g, 65.3 mmol) in 150 ml of H 2 O. The reaction mixture was heated to 80° C. for four hours. The reaction was cooled to room temperature, diluted with H 2 O and extracted with CHCl 3 . The organic extracts were dried over MgSO 4 and evaporated to yield 10.7 g (a yield of 87%) of as a brick red solid. Using various analytical procedures, this solid was determined to be 2-methyl-6 nitroquinoxaline.
2-Methyl-6-Aminoquinoxaline
A thick-walled Parr hydrogenation flask was charged with 2-methyl-6-nitroquinoxaline (10.0 g, 52.9) and CH 3 OH (200 ml) The flask was flushed with a stream of N 2 and 10% by weight palladium on charcoal (500 mg) was added. The flask was pressurized with H 2 to 50 psi and maintained at this pressure for three hours. The reaction mixture was filtered through acid washed silicon dioxide and concentrated in vacuo to yield a tan solid. The crude material was chromatographed (SiO 2 ; 95/5 CHCl 3 /CH 3 OH saturated with NH 3 (g)) and recrystallized from benzene to yield 7.4 g (a yield of 88%) of a tan solid. Using various analytical procedures, this tan solid was determined to be 2-methyl-6-aminoquinoxaline.
2-Methyl-5-bromo-6-(2-imidazolin-2-ylamino) quinoxaline
By a series of reaction steps analogous to the reaction steps described above in Example 1, the title compound (mp. 260° C.) was prepared starting with 2-methyl-6-aminoquinoxaline in place of 6-aminoquinoxaline.
(±)2-methyl-5-Bromo-6-(2-imidazolin-2-ylamino)-1, 2, 3, 4-tetrahydroquinoxaline
A solution of 2-methyl-5-bromo-6-(2-imidazolin-2-ylamino) quinoxaline (40.5 mg, 0.132 mmol) in acetic acid was cooled to 10° C. and carefully treated with NaBH 4 (5.0 mg, 0.132 mmol). The reaction mixture was stirred for 15 minutes before the solvent was removed in vacuo. The residue was dissolved in H 2 O, treated with solid NaOH to pH 13 and extracted with CHCl 3 . The combined organic extracts were dried over MgSO 4 and concentrated in vacuo to yield a yellow oil. The crude material was chromatographed (SiO 2 , 80/20 CHCl 3 /CH 3 OH saturated with NH 3 (g)) to yield 21.8 mg (a yield of 53%) of a tan solid, mp 203-205° C. Using various analytical procedures, this tan solid was determined to be (±) 2-methyl-5-bromo-(2-imidazolin-2-ylamino)-1,2,3,4-tetrahydroquinoxaline.
EXAMPLE 3
Preparation of (±) 3-Methyl-5-bromo-6-(2-imidazolin-2-ylamino)-1, 2, 3, 4-tetrahydroquinoxaline
3-Methyl-6-aminoquinoxaline
Pyruvic aldehyde (Aldrich, 892 mg, 4.95 mmol, 40% solution H 2 O) was added dropwise to a stirred solution of 1, 2, 4-triaminobenzene hydrochloride (1.0 g, 4.95 mmol) dissolved in 10% aqueous Na 2 CO 3 (15 ml). The mixture was heated at 1OO° C. for two hours before cooling to room temperature. The mixture was extracted with CHCl 3 . The combined organic extracts were dried over MgSO 4 and concentrated in vacuo to yield a brown solid. The crude product was chromatographed (SiO 2 , 95/5 CHCl 3 /CH 3 OH saturated with NH 3 (g)) to yield 616 mg (a yield of 75%) of a yellow crystalline solid. An analytical sample was prepared by recrystallization from benzene, mp 170-173° C. Using various analytical procedures, the solid was determined to be 3-methyl-6-aminoquinoxaline.
(±)3-Methyl-5-bromo-6-(2-imidazolin-2-ylamino)-1, 2, 3, 4tetrahydroquinoxaline
By a series of reaction steps analogous to the reaction steps described above in Example 2, the title compound (mp 250-251° C.) was prepared starting with 3-methyl-6-aminoquinoxaline in place of 2-methyl-6-aminoquinoxaline.
EXAMPLE 4
Preparation of 5-Bromo-6-(2-imidazolin-2-ylamino)-1,4-dimethyl-1,2,3,4-tetrahydroquinoxaline, 5-Bromo-6-(2-imidazolin-2-ylamino)-1-methyl-1,2,3,4-tetrahydroquinoxaline and 5-Bromo-6-(2-imidazolin-2-ylamino)-4-methyl-1,2,3,4-tetrahydroquinxoaline.
5-Bromo-6-(2-imidazolin-2-ylamino) quinoxaline (291 mg, 1 mmol) is suspended in CH 3 OH (2 ml) and treated with glacial acetic acid (1 ml). The reaction mixture is treated with NaCNBH 3 (252mg, 4 mmol) and paraformaldehyde (450 mg, 5 mmol) and stirred at room temperature for 4-8 hours. The reaction mixture is quenched with H 2 O (5 ml), basified with solid NaOH (3g) to pH>12 and extracted with CHCl 3 . The CHCl 3 extracts are dried over MgSO 4 , concentrated in vacuo and chromatographed (SiO 2 , 80/20 CHCl 3 /CH 3 OH saturated with NH 3 (g)) to yield the individual title compounds. Each of these title compounds is tested and is found to have one or more useful therapeutic effects which known alpha 2 agonists exhibit.
EXAMPLE 5
Preparation of 5-Bromo-6-(2-imidazolin-2-ylamino)-1,4-diethyl-1,2,3,4-tetrahydroquinoxaline, 5-Bromo-6-(2-imidazolin-2-ylamino)-1-ethyl-1,2,3,4-tetrahydroquinoxaline and 5-Bromo-6-(2-imidazolin-2-ylamino)-4-ethyl-1,2,3,4tetrahydroquinoxaline
The individual title compounds are prepared using the method illustrated in Example 5 except that acetaldehyde (220 mg, 5 mmol) is substituted for paraformaldehyde and the reaction time is 6-12 hours instead of 4-8 hours. Each of these title compounds is tested and is found to have one or more useful therapeutic effects which known alpha 2 agonists exhibit.
EXAMPLES 6 TO 8
The three (3) tetrahydroquinoxaline derivatives produced in accordance with Examples 1 to 3 were tested to determine what effect, if any, these materials have on intraocular pressure.
Each of these materials was dissolved in distilled water at a concentration of 0.1% (W/V). Each of these solutions was administered topically and unilaterally to one eye of a drug-naive unanesthetized New Zealand white rabbit in a single 50 micro liter drop. The contralateral eye received an equal volume of saline prior to determining the intraocular pressure after the mixture was administered. Also, approximately 10 micro liters of 0.5% (W/V) proparacaine (topical anesthetic) was applied to the corneas of each of the rabbits before determining intraocular pressure. As a control test, six (6) other drug-naive, unanesthetized New Zealand white rabbits were treated and tested as described above except that no tetrahydroquinoxaline derivative was included in the solutions administered to the eyes.
The intraocular pressure was determined in both eyes of each rabbit before and after the solutions were administered. Such intraocular pressure determinations were made in the conventional manner using conventional equipment.
Results of these IOP determinations were as follows:
__________________________________________________________________________ Difference In Intraocular Pressure, percentActive Initial Effect Maximum Effect Maximum EffectExampleMaterial On Treated Eye On Treated Eye On Untreated__________________________________________________________________________ Eye ##STR5## +10.7 ± 3.6 -16.0 ± 3.3 N.S.7 ##STR6## N.S. -15.1 ± 3.3 -8.6 ± 2.48 ##STR7## N.S. -12.5 ± 2.2 N.S.Control N.S. N.S. N.S.__________________________________________________________________________ N.S. means that the effect was not statistically significant.
These results indicate that all of 5-bromo-6-(2-imidazolin-2-ylamino)-1,2,3,4 tetrahydroquinxaline (Example 6), (±) 2-methyl-5-bromo-6-(2-imidazolin-2-ylamino)-1, 2, 3, 4 tetrahydroquinoxaline (Example 7), and (±) 3-methyl-5-bromo-6-(2-imidazolin-2-ylamino)-1, 2, 3, 4 tetrahydroquinoxaline (Example 8) are effective to reduce intraocular pressure in the treated rabbit eye, i.e., the eye to which the active material was directly administered. The tetrahydroquinoxaline derivative in Example 6 had an initial effect in the treated eye of raising the intraocular pressure. The tetrahydroquinoxaline derivative in Example 7 also resulted in reducing the intraocular pressure in the untreated rabbit eye.
EXAMPLES 9 TO 11
The tetrahydroquinoxalines produced in Examples 1 to 3 were tested for activity using the following in vitro methods.
Rabbit Vas Deferens: Alpha 2 Adrenergic Receptors
New Zealand white rabbits (2-3 kg) were killed by CO 2 inhalation and the vasa deferentia removed. The prostatic ends of the vasa deferentia (2-3 cm lengths) were mounted between platinum ring electrodes in 9 ml organ baths and bathed in Krebs bicarbonate solution of the following composition (millimolar): NaCl 118.0; KCl 4.7; CaCl 2 2.5; MgSO 4 1.2; KH 2 PO 4 1.2; glucose 11.0; NaHCO 3 25.0; which solution was maintained at 35° C. and bubbled with 95% O 2 and 5% CO 2 . The initial tension of the vas deferens was 0.5 g. The tissues were left to equilibrate for 30 minutes before stimulation was started. Vasa were then field stimulated (0.1 Hz, 2 ms pulse width at 90 mA) using a square wave stimulator (WPI A310 Accupulser with A385 stimulus). The contractions of the tissue were recorded isometrically using Grass FTO3 force-displacement transducers and displayed on a Grass Model 7D polygraph. Cumulative concentration-response curves were obtained for the tetrahydroquinoxaline being tested with a 4 minute contact time at each concentration. The reduction in response height was measured and expressed as a percentage of the height of the response before the addition of tetrahydroquinxoaline. Concentration response curves for each of tetrahydroquinoxalines were plotted. The effective concentration required for a 50% reduction in response height, expressed as EC 50 , were obtained from these curves and are set forth below.
Rabbit Aorta: Alpha 1 Adrenergic Receptors., Rabbit Saphenous Vein: Alpha 3 Adrenerqic Receptors
Thoracic aorta and saphenous vein specimens were obtained from albino rabbits that were killed by CO 2 inhalation. The aorta and saphenous vein were each cut into 3 mm rings. Tissues were placed in Krebs-Hensleit solution of the following composition (millimolar): NaCl 119; KCl 4.7; MgSO 4 1.5, KH 2 PO 4 1.2; CaCl 2 2.5; NaHCO 3 25 and glucose 11.0. The solution also contained cocaine (0.1 millimolar) to block neuronal uptake and EDTA (30 micromolar) and ascorbic acid (5 micromolar) to prevent oxidation of the tetrahydroquinoxaline being tested. Tissues were hung in 10 ml organ baths and tension was measured via Grass FTO3 force-displacement transducers. Resting tension was 1 g and 2 g for the saphenous vein and aorta, respectively. The solution was gassed with 95% O 2 and 5% CO 2 and maintained at 37° C. Tissues were allowed to equilibrate for 2 hours before stimulation and the cumulative addition of the tetrahydroquinoxaline being treated was started. Tissue stimulation was performed as with the rabbit vas deferens, described above. The contractions of the tissue were recorded isometrically as for the rabbit vas deferens assay. Cumulative concentration response curves were obtained and the EC50 value developed for each tetrahydroquinoxaline tested in a manner similar to that for the rabbit vas deferens assay.
Results of these in vitro tests were as follows:
__________________________________________________________________________ EC.sub.50, nanomolar Rabbit Vas RabbitExampleMaterial Rabbit Aorta Deferens Saphenous Vein__________________________________________________________________________ 9 ##STR8## 1130 ± 207 (n = 8) 1.75 (n = 1) 92 ± 19 (n = 6)10 ##STR9## 6750 ± 116 (n = 3) 35.3 ± 3.9 (n = 5) 581 ± 29 (n = 2)11 ##STR10## 1060 ± 271 (n = 3) 21.3 ± 3.0 (n = 2) --__________________________________________________________________________
n is equal to the number of times the particular test was run.
These results indicate that the present tetrahydroquinoxalines have some activity with respect to all of the alpha 1, alpha 2 and alpha 3 adrenergic receptors. However, these materials have a particularly high activity with respect to the alpha 2 adrenergic receptors. Thus, the present tetrahydroquinoxalines are properly classified as alpha 2 agonists.
EXAMPLE 12
The tetrahydroquinoxaline produced in Example 1 was tested for renal and blood pressure effects using the following method.
Young male (20-24 weeks old) Sprague-Dawley rats were used. Under ketamine (60 mg/kg b.wt. i.m.) and pentobarbital (i.p. to effect) anesthesia, medical grade plastic tubes were implanted into the abdominal aorta and vena cava via the femoral vessels. In addition, a Silastic-covered stainless steel cannula were sewn in the urinary bladder. After the surgery, the rats were housed individually and were allowed free access to food and water until the day of the experiment.
For about 7 to 10 days before surgery and during recovery, the rats were accustomed to a restraining cage by placement in the cage for 2 to 3 hours every 2nd and 3rd day. The cage was designed for renal clearance studies (a model G Restrainer sold by Braintree Scientific, Inc., Braintree, Massachusetts). The animals' adjustment to the cage was judged by the stability of blood pressure and heart rate.
For an experiment, a rat was placed in the restraining cage, and the arterial line was connected to a Statham pressure transducer and a Beckman Dynograph R61 to monitor the mean arterial blood pressure, hereinafter referred to as MAP. The venous line was connected to an infusion pump system for infusion of replacement fluid. The tetrahydroquinoxaline was administered intraduodenally by cannula. The bladder cannula was extended with a silastic tube to facilitate collection of urine in preweighed tubes. The volume of urine was measured gravimetrically. Body weight was recorded before and after the experiment.
Throughout the experiments, 0.9% NaCl containing 10% polyfructosan (Inutest) and 1% sodium PAH was infused at a rate of 20 microliters/min. An equilibration period of 60 minutes was followed by two consecutive 30 minute control clearance periods. Then, the tetrahydroquinoxaline was administered for 90 minutes. Urine collection was resumed 10 minutes after the start of tetrahydroquinoxaline administration. By this time the washout of the bladder cannula dead space (approximately 200 microliters) was completed. Three additional clearance measurements were made. Blood samples (150 microliters) were collected at the midpoint of urine collections. Plasma was separated and saved for analyses, and the cells were resuspended in saline and returned to the animals. Water and sodium loss was carefully replaced i.v. by a variable speed infusion pump.
Results of these tests were as follows:
______________________________________Results of these tests were as follows:Dose of Increase inTetrahydro- Urine Flow,quinoxaline of microliters/ Increase inExample 1, min./100 g of MAP,mg/kg of body weight body weight mm Hg______________________________________0.01 0 00.03 4 00.1 16 00.3 24 2.51 32 8______________________________________
The test was run 3 times. The results at 0.1 mg/kg of body weight and higher dosages represent statistically significant differences (i.e., in a conventional statistical analysis of the date, P is less than 0.05).
These results indicate that the present substituted quinoxalines produce relatively large renal effects. Further, these results show that such renal effects are produced without a correspondingly large effect on the blood pressure.
EXAMPLE 13
The tetrahydroquinoxaline produced in Example 1 was tested for anti-diarrheal effects and blood pressure effects using the following method.
Cecectomies were performed in unfasted rats as follows. Under anesthesia with methohexital (60 mg/kg. i.p.), a laparotyphlectomy was initiated with a 2 cm midventral incision. The cecum was lifted from the abdominal cavity and exteriorized onto a gauze drape. The cecal apex was freed by severing the avascular area of the mesocecum. Next, a ligature of #1 silk suture was positioned so as to occlude the cecum and its vasculature without compromising ileo-colonic patency. After the ligature was secured and ileo-colonic patency confirmed, the cecum was resected, and the remaining exposed cecal mucosa was washed with saline and cauterized. The intestinal segment was then returned to the abdominal cavity, and the abdominal muscle facia closed with interrupted 4/0 chromic-gut sutures. The dermal incision was closed with 9 mm stainless steel wound clips that were removed approximately 1 week post surgery. An arterial line-was also implanted into the abdominal aorta and vena cava via the femoral vessels, in a manner similar to that described in Example 10. Immediately following the surgical procedure, animals were returned to their cages and allowed free access to food and water. Animals were permitted at least 48 hour recovery period before being used in experiments.
The cecectomized rats were put into individual wire-bottomed cages placed over sheets of clean paper, and deprived of food and water for the duration of the assay. The MAP was monitored, as described in Example 10, throughout the assay. Rats were given a 2 hour acclimatization period prior to the start of the assay in order to eliminate sporadic episodes of anxiety-induced defecation. During this period they were observed also for consistent occurrences of pelleted feces; an animal producing other than a pelleted stool was disqualified from the study.
Diarrhea was induced with oral administration of 16,16-dimethyl prostaglandin E 2 (dmPGE 2 ) in 3.5% EtOH. The tetrahydro- quinoxaline was administered by gavage after the onset of diarrheal episodes. The cage papers were removed and examined at 30 minute intervals for dmPGE 2 -induced diarrhea. Fecal output was recorded at each interval and fecal consistency is assigned a numerical score in each experimental group as follows: 1=normal pelleted stool, 2=soft-formed stools; 3=water stool and/or diarrhea. The fecal output index (FOI) is defined as the summation of the number of defecation episodes and their ranked consistency score within an observation period.
Results of these tests were as follows:
______________________________________Results of these tests were as follows:Dose of Tetrahydro- Percent Reduction Increase inquinoxaline of Example 1, in FOI versus MAP,mg/kg of Body Weight,p.o. dmPGE.sub.2 Control mm Hg______________________________________0.01 17 00.03 60 00.10 57 00.30 76 01.00 98 03.00 98 1010.00 100 25______________________________________
These results indicate that the tetrahydroquinoxaline produced in Example 1 provided substantial anti-diarrheal effects. Further, these results show that such anti-diarrheal effects are produced with no or a relatively minimal effect in blood pressure.
While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.
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A compound selected from the group consisting of those having the formula: ##STR1## and pharmaceutically acceptable acid addition salts thereof, wherein R 1 and R 4 are independently selected from the group consisting of H and alkyl radicals containing 1 to 4 carbon atoms, R 2 and R 3 are independently selected from the group consisting of H, OXO, and alkyl radicals containing 1 to 4 carbon atoms, the 2-imidazolin-2-ylamino group may be in any of the 5-, 6-, 7- or 8- positions of the quinoxaline nucleus, and R 5 , R 6 and R 7 each is located in one of the remaining 5-, 6-, 7- or 8- positions of the quinoxaline nucleus and is selected from the group consisting of Cl, Br, H and alkyl radicals containing 1 to 3 carbon atoms. Such compounds, when administered to a mammal, provide desired therapeutic effects, such as alteration in the rate of fluid transport in the gastrointestinal tract, reduction in intraocular pressure, and increase in renal fluid flow.
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BACKGROUND OF THE INVENTION
[0001] 1). Field of the Invention
[0002] This invention relates generally to an electronic assembly, typically of the kind having a package substrate secured to a printed circuit board utilizing solder bumps.
[0003] 2). Discussion of Related Art
[0004] Integrated circuits are often manufactured in and on semiconductor wafers which are subsequently cut into individual semiconductor chips. A chip is then mounted to a package substrate and electrically connected thereto. The package substrate is then mounted to a printed circuit board.
[0005] Solder balls are usually located on the surface of the package substrate which is located against the printed circuit board. The combination is then heated and allowed to cool so that the solder balls form solder bumps which secure the package substrate structurally to the printed circuit board, in addition to electrically connecting the package substrate to the printed circuit board.
[0006] Electronic signals can be provided through the solder bumps between the printed circuit board and the integrated circuit. Other ones of the solder bumps provide power and ground to the integrated circuit. It may occur that high currents flow through some of the solder bumps, in particular those providing power or ground to the integrated circuit. These high currents may cause damage to the solder bumps. The solder bumps providing power, ground and signal communication are also usually equally spaced from one another thus taking up similar amounts of space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention is described by way of examples with reference to the accompanying drawings wherein:
[0008] [0008]FIG. 1 is a cross-sectional side view illustrating components of an electronic assembly according to an embodiment of the invention;
[0009] [0009]FIG. 2 is a view similar to FIG. 1 after the components are brought together, heated and allowed to cool;
[0010] [0010]FIG. 3 is a plan view illustrating the layout of solder bumps and vias of a printed circuit board of the electronic assembly;
[0011] [0011]FIG. 4 is a side view illustrating more components of the electronic assembly; and
[0012] [0012]FIG. 5 is a plan view of a printed circuit board according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] [0013]FIG. 1 of the accompanying drawings illustrates components of an electronic assembly 10 before being secured to one another. The electronic assembly 10 includes a package substrate subassembly 12 and a printed circuit board subassembly 14 .
[0014] The printed circuit board subassembly 14 includes a printed circuit board 16 , vias 18 , and contact pads 20 .
[0015] The printed circuit board 16 includes a number of layers including a power plane 22 , a ground plane 24 , and other layers 26 . The power plane 22 is separated from a ground plane 24 by one of the layers 26 . Another one of the layers 26 is located on top of the power plane 22 and a further one of the layers 26 is located on a lower surface of the ground plane 24 . The power and ground planes 20 and 24 are thus separated from one another by one of the layers 26 and spaced from upper and lower surfaces of the printed circuit board 16 by other ones of the layers 26 .
[0016] The vias 18 are located in the printed circuit board 16 and extend from the upper surface thereof to the lower surface thereof through the layers 22 , 24 , and 26 . The vias 18 include power vias 18 A, ground vias 18 B and signal vias 18 C. The power vias 18 A have lower ends connected to the power plane 22 . The ground vias 18 B have lower ends connected to the ground plane 24 . The signal vias 18 C are disconnected from the power and ground planes 22 and 24 .
[0017] The contact pads 20 include a power contact pad 20 A, a ground contact pad 20 B and signal contact pads 20 C. The power contact pad 20 A has a height measured in a direction from the bottom of the paper to the top of the paper, a width as measured into the paper, and a length as measured from the left to the right of the paper. The length is a multiple of the width. The power contact pad 20 A is located on all the power vias 18 A. Each one of the power vias 18 A is attached and connected to the power contact pad 20 A at a respective location along the length of the power contact pad 20 A. As such, the power vias 18 A connect the power contact pad 20 A in parallel to the power plane 22 . In another embodiment the vias may be located outside the contact pads in an arrangement commonly referred to as a “dogbone” configuration.
[0018] The ground contact pad 20 B, similarly, has a height, a width, and a length which is a multiple of the width. The ground contact pad 20 B is located on all the ground vias 18 B so that each ground via 18 B has a respective upper end connected to the ground contact pad 20 B at a respective location along its length.
[0019] Each signal contact pad 20 C is located on and connected to a respective one of the signal vias 16 C. Each signal contact pad 20 C is disconnected from every other contact pad 20 .
[0020] The package substrate subassembly 12 includes a package substrate 30 , vias 32 , bond pads 34 , and solder balls 36 . The package substrate 30 is also a multi-layer substrate having a ground plane and a power plane. The vias include power vias 32 A, ground vias 32 B, and signal vias 32 C. Each one of the power vias 32 A has an upper end connected to a ground plane in the package substrate 30 and each one of the ground vias 32 B has an upper end connected to a ground plane in the package substrate 30 .
[0021] The bond pads 34 include the power bond pads 34 A, ground bond pads 34 B, and signal bond pads 34 C, all located on a lower surface of the package substrate 30 . Each power bond pad 34 A is located on a respective lower end of a respective one of the power vias 32 A, each ground bond pad 34 B is located on a respective lower end of a respective ground via 32 B, and each signal bond pad 34 C is located on a respective lower end of a respective signal via 32 C.
[0022] The solder balls 36 include power solder balls 36 A, ground solder balls 36 B, and signal solder balls 36 C. Each power solder ball 36 A is located on a respective lower surface of a respective one of the power bond pads 34 A, each ground solder ball 36 B is located on a respective lower surface of a respective ground bond pad 34 B, and each signal solder ball 36 C is located on a respective lower surface of respective signal bond pads 34 C.
[0023] Each respective power via 32 A is aligned with one power bond pad 34 A, one power solder ball 36 A, and one power via 18 A. Center points of the power solder balls 36 A are spaced from one another by about 1 mm. A center point of the power solder ball 36 A on the right is spaced from a center point of the ground solder ball 36 B on the left by about 1.2 mm. Center points of the ground solder balls 36 B are spaced from one another by about 1 mm. A center point of the ground solder ball 36 B on the right is spaced from a center point of the signal solder ball 36 C on the left by about 1.2 mm. Center points of the signal solder balls 36 C are spaced from one another by about 1.2 mm. All the solder balls 36 A, B, and C have equal mass and size. Therefore, the combined mass of the power solder balls 36 A divided by the number of power vias 18 A equals the combined mass of the ground solder balls 36 B divided by the number of ground vias 18 B, and equals the combined mass of the signal solder balls 36 C divided by the number of signal vias 18 C.
[0024] The package substrate subassembly 12 is lowered onto the printed circuit board subassembly 14 so that lower surfaces of the solder balls 36 contact upper surfaces of the contact pads 18 A. All the power solder balls 36 A contact the power contact pad 20 A, all the ground solder balls 36 B contact the ground contact pad 20 B, and each signal solder ball 36 C contacts a respective one of the signal contact pads 20 C.
[0025] The combination of the package substrate assembly 12 and the printed circuit board subassembly 14 is then located in a reflow furnace. The solder balls 36 are heated to above their melting temperature so that they melt. The power solder balls 36 A combine when they melt due to their relative close spacing and the ground solder balls 36 B combine when they melt due to their relative close spacing. The power solder balls 36 A however do not combine with the ground solder balls 36 B. The signal solder balls 36 C remain disconnected from one another from the ground solder balls 36 B and from the power solder balls 36 A.
[0026] The combination of the package substrate subassembly 12 and the printed circuit board subassembly 14 is then removed from the reflow furnace and allowed to cool so that the material of the melted solder balls again solidifies. The solidified material of the power solder balls 36 A is represented in FIG. 2 of power solder bumps 40 B, the combination of the ground solder balls 36 B is represented as a ground solder bump 40 B, and the melted and reflowed signal solder balls 36 C is represented by signal solder bumps 40 C.
[0027] Each one of the power solder bumps 40 A has a height, a width, and a length with the width and length of the power solder bump 40 A correspond to the width and the length of the power contact pad 20 A. Similarly, the ground solder bump 40 B has a height, a width, and a length, the width and length corresponding to the width and length of the ground contact pad 20 B. As such, the power solder bump 40 B has a length which is a multiple of its width and the ground solder bump 40 B has a length which is a multiple of its width.
[0028] Upper ends of the power vias 18 A are connected through the power contact pads 20 A to respective points of the power solder bump 40 A along its length and upper ends of the ground vias 18 B are connected to the ground contact pad 20 B to the ground solder bump 40 B at respective locations along its length. The power solder bump 40 A is thus connected in parallel through the power vias 18 A to the power plane 22 and the ground solder bump is connected in parallel through the ground vias 18 B to the ground plane 24 .
[0029] An advantage of combining the power solder balls 36 A and combining the ground solder balls 36 B is that they can be located closer to one another. More space is so freed up for additional ones of the signal solder balls 36 C. Another advantage of combining the power solder balls 36 A and combining the ground solder balls 36 B is that potential high currents through individual ones of the balls 36 A or B can be distributed through the larger solder bumps 40 A or 40 B.
[0030] [0030]FIG. 3 is a more accurate representation of the relative positioning of the power and ground solder bumps 40 A and 40 B. The power and solder bumps 40 A and 40 B are represented by rectangles. The signal solder bumps 40 C are represented by larger circles. The power ground and signal vias 18 A, 18 B, and 18 C are represented by the smaller circles.
[0031] It can be seen that the power and ground solder bumps 40 A and 40 B are located in lines parallel to one another, directly adjacent one another with a respective ground solder bump 40 B located between two of the power solder bumps 40 A. A surface of one of the power solder bumps 40 A thus faces a respective surface of one of the ground solder bumps 40 B to form a plurality of capacitors. In the example illustrated, there are three power solder bumps 40 A and three ground solder bumps 40 D and five capacitors are created. The capacitors assist in reducing resistive and inductive time delay of power or ground signals. All the power and ground vias 18 A and 18 B are located over a rectangular area where there are none of the signal vias 18 C and all the signal vias are located around the rectangular area where all the power and ground vias 18 A and 18 B are located.
[0032] [0032]FIG. 4 illustrates more components of the electronic assembly. In addition to the package substrate 30 and the printed circuit board 16 , the electronic assembly 10 further includes a semiconductor chip 50 . The semiconductor chip 50 has an integrated circuit of electronic components therein The semiconductor chip 50 is mounted on the package substrate 30 and electrically connected thereto. Electronic signals can be provided to and from the integrated circuit in the semiconductor die 50 and the printed circuit board 16 through the solder bumps 40 and the package substrate 30 .
[0033] [0033]FIG. 5 illustrates another manner in which capacitors can be created with power and ground solder bumps. Similar reference numerals are used as in the embodiment of FIG. 3. A power solder bump 140 has a plurality of limbs 140 A-E. The limbs 140 A-D all lead off the limb 140 E. A ground bump 150 is provided having limbs 150 A-E. The limbs 150 A-D lead off the limb 150 E. The limbs 150 A-D are located between the limbs 140 A-D so that the limbs 140 are alternated by the limbs 150 A-D. It has been found that a larger capacitor can be created over a given surface area by “fanning” the limbs into one another as illustrated in FIG. 5.
[0034] While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the current invention, and that this invention is not restricted to the specific constructions and arrangements shown and described since modifications may occur to those ordinarily skilled in the art.
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Solder bumps are created on a substrate of an electronic assembly having lengths that are longer than the widths. The solder bumps are created by locating solder balls of power or ground connections close to one another so that, upon reflow, the solder balls combine. Signal solder balls however remain separated. Capacitors are created by locating power solder bumps adjacent ground solder bumps and extending parallel to one another.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to telecommunications systems, for example wireless digital cellular systems, employing complex or quadrature modulated information signals containing data organized into successive time slots, each slot containing a series of pilot bits and a series of data bits, and more specifically to an apparatus and method for channel estimation and de-rotation of such an information signal received via a channel.
2. Description of the Related Art
In planned third generation digital wireless cellular systems known as Uniform Mobile Telephone System (UMTS), Wideband Code Division Multiple Access (W-CDMA), and Third Generation (e.g. 3G Partnership Project) spread spectrum information signals are used which contain data grouped into slots, each slot consisting of a predetermined series of N pilot pilot bits in a first portion of the slot and a series of N data data bits in the second portion of the slot. It is known to use various types of filtering schemes, ranging from simple to complex, to achieve channel estimation and de-rotation of a despread received spread spectrum information signal by synchronizing with the pilot bits. The nature of the estimation error achieved with prior art filtering schemes varies, but generally the error propagates from slot, sometimes increasing over time.
While decision feedback loops are known for other purposes, the prior art has not considered the possibility of using a decision feedback loop for channel estimation and de-rotation of a spread spectrum signal received via a channel.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a decision feedback loop apparatus and method for a receiver for channel estimation and de-rotation of a received signal. It is a further object that the decision feedback loop is implemented in a manner to mitigate propagation of the estimation error from slot to slot.
This and other objects of the present invention are satisfied by a decision feedback loop which uses the known sequence of pilot bits to initialize and train the feedback loop during each slot. This continued sloe by slot re-initialization and re-training prevents the estimation error in one slot from propagating to the next.
In accordance with the invention, a decision feedback loop apparatus for a receiver for channel estimation and de-rotation of complex input symbols derived from a sampled information signal received via a channel, which information signal contains data organized into successive time slots, each slot containing a predetermined series of pilot bits during a first portion of the slot and a series of data bits during a second portion of the slot, comprises a first multiplier for multiplying the complex input symbols with estimated conjugate channel coefficients, which are derived from a feedback signal, to form complex soft symbols to be used for channel decoding, a hard decision device for forming complex hard symbols from the complex soft symbols, a pilot generator for generating a series of complex pilot symbols corresponding to the predetermined series of pilot bits in the information signal, and a second multiplier for multiplying a first signal at a first input, which is derived from the complex input signal, with a second signal at a second input to form a feedback signal at an output. The invention is characterized in that the second signal is derived from the complex pilot symbols during the first portion of the slot and from the complex hard symbols during the second portion of the slot.
Similarly, in accordance with the invention, a decision feedback loop method for a receiver for channel estimation and de-rotation of complex input symbols derived from a sampled information signal received via a channel, which information signal contains data organized into successive time slots, each slot containing a predetermined series of pilot bits during a first portion of the slot and a series of data bits during a second portion of the slot, comprises multiplying the complex input symbols with estimated conjugate channel coefficients, which are derived from a feedback signal, to form complex soft symbols to be used for channel decoding, forming complex hard symbols from the complex soft symbols, generating a series of complex pilot symbols corresponding to the predetermined series of pilot bits in the information signal, and multiplying a first signal, which is derived from the complex input signal, with a second signal to form a feedback signal. The inventive method is characterized by the act of deriving the second signal from the complex pilot symbols during the first portion of the slot and from the complex hard symbols during the second portion of the slot.
Another aspect of the invention is that the estimated channel coefficients are derived by applying a filter to the feedback signal.
Other objects, features and advantages of the present invention will become apparent upon perusal of the following detailed description when taken in conjunction with the appended drawing, wherein:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a simplified decision feedback loop for channel estimation and de-rotation of complex input symbols derived from a sampled information signal in accordance with the present invention;
FIG. 2 shows the time slot structure of the information signal;
FIG. 3 shows a more detailed decision feedback loop which corresponds to an alternative embodiment to that shown in FIG. 1;
FIG. 4 shows a wireless telecommunications system including a mobile station having a channel estimation and de-rotation decision feedback loop in accordance with the invention; and
FIG. 5 shows a wireless handset or mobile station for incorporating the decision feedback loop for receiving purposes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 4 of the drawing for the purpose of orientation, there is shown a mobile station MS transceiver in communication with a base station BS of a wireless cellular telecommunication system, e.g. of the UMTS, W-CDMA, 3GPP types employing spread spectrum signals transmitted and received via the antennae A′, A. At the functional level of detail shown in FIG. 4, mobile station MS is conventional including a receive/transmit switch or diplexer 100 coupling antenna A to the input of RF receiving apparatus, including a cascade of a RF section receive processing block 200 a and a baseband section receive processing block 300 a , and also coupling antenna A to the output of RF transmitting apparatus, including a cascade of a baseband section transmit processing block 300 b and a RF section transmit processing block 200 b.
RF section receive processing block 200 a includes a cascade of a low noise amplifier 210 and frequency downconverter 220 for conversion from RF to baseband, e.g. a direct conversion quadrature mixer (not shown), and baseband section receive processing block 300 a includes a cascade of an analog to digital converter 310 , a complex despreader 320 for applying a despreading code, a channel estimation and de-rotation decision feedback loop 330 , a channel decoder 340 having a digital output for received decoded data signals, and a digital to analog converter 350 for producing an analog output e.g. representing received decoded voice signals. These digital and analog outputs are provided to a user interface 400 for use by and/or sensory stimulation of a user, and the user interface provides to analog and digital inputs of baseband section transmit processing block 300 b user responsive voice and/or data signals, respectively.
Baseband section transmit processing block 300 b digitally encodes and applies a spreading code to the voice signals, after an analog to digital conversion, and also encodes and spreads the data signals, converts the encoded and spread signals to digital form, and supplies these encoded and spread signals, after a digital to analog conversion, to RF section transmit processing block 200 b for power amplification and frequency upconversion to RF.
For further orientation, reference is made to FIG. 5 of the drawing which shows the mobile station MS as including the antenna A, an RF section 500 (which implements the receive transmit switch or diplexer 100 and RF section receive and transmit processing 200 a , 200 b of FIG. 4 ), a baseband section (which implements baseband section receive and transmit processing 300 a , 300 b of FIG. 4 ), and a user interface section (which implements user interface 400 of FIG. 4 ). Baseband section 600 includes digital signal processor (DSP) 610 , microprocessor (lP) 120 , read only memory (ROM) 630 , random access memory (RAM) 640 , analog to digital converter (A/D) 650 , and digital to analog converter (D/A) 660 . User interface section 700 includes microphone 710 , speaker 720 , keypad 730 , and a display driver 740 which drives an LCD display 750 .
The present invention pertains particularly to channel estimation and de-rotation decision feedback loop 330 of FIG. 4 which is specially configured for slot by slot re-initialization and re-training. As is conventional, the channel estimation and derotation functionality is implemented by DSP operating on program instructions stored in ROM 630 .
The relevant slot structure, as shown in FIG. 2, is seen to comprise a series of time slots, e.g. i−2, 1−1, i, i+1, i+2, each consisting of a predetermined sequence of N pilot pilot symbols during a first portion of the slot followed by a larger number, N data , of data symbols during a second portion of the slot.
Channel estimation and de-rotation decision feedback loop 330 is shown in simplified form in FIG. 1 in conjunction with complex despreader 320 which supplies complex input symbols to a first inputs of first and second multipliers 332 , 333 of feedback loop 330 . First multiplier 332 also receives at a second input estimated complex conjugate channel coefficients E, and produces at its output complex soft symbols supplied to channel decoder 340 (FIG. 5) and also to a hard decision device 335 which converts the complex soft symbols to complex hard decisions. The output of hard decision device 335 is applied to one input of a selector device 336 , shown as a switch, whose other input is fed by the output of complex pilot symbols generator 339 , and whose output is coupled to a second input of second multiplier 333 via a complex conjugate device 338 . Selector switch 336 is controlled by a timing device 337 such that the signal coupled to the second input of second multiplier 333 is derived from the complex pilot symbols output from generator 339 during the first portion of the slot and from the complex hard decisions output from hard decision device 335 during the second portion of the slot.
Optionally, complex conjugate device 338 a may be utilized which is located in the path between the output of complex despreading device 320 and the first input of second multiplier 333 rather than locating complex conjugate device 338 in the path between the output of selector device 336 and the second input of multiplier 333 . In either event, the output of second multiplier 333 is a feedback signal F which is applied to a low pass filter 334 whose output constitutes the estimated complex conjugate channel coefficients E applied to the second input of first multiplier 332 .
FIG. 3 illustrates channel estimation and de-rotation decision feedback loop 330 in more detail, utilizing the alternative in which the complex conjugate device appears intermediate the output of despreader 320 and the first input of second multiplier 337 after a one sampling interval delay 337 . Hard decision device 334 is seen to comprise a complex to real/imaginary device having real and imaginary component outputs which are compared with a threshold of zero in comparators 330 b and 330 c respectively, to produce binary hard decisions. These binary hard decisions for the real and imaginary components are applied to binary to numeric converters 330 d and 330 e , respectively, the outputs of which feed device 330 f for forming a complex numeric therefrom. The output of device 330 f is applied to one input of selector device 336 via one sampling interval delay 330 g , and the output of selector device feeds the second input of multiplier 333 .
Complex pilot symbols generator 339 comprises a pilot vector generator 339 a which generates at its output the known sequence of pilot symbols in the form of a complex vector. The output of generator 339 a is applied to the input of a complex vector to scalar converter 339 b via one sampling interval delay 339 b , and the output of converter 339 c forms the output of complex pilot symbols generator 339 which the other input of selector device 336 .
Further, the low pass filter 334 between the output of second multiplier 333 and the input of first multiplier 332 is seen to be implemented by an infinite impulse response (iir) digital filter.
It should now be appreciated that the objects of the present invention have been satisfied by the present invention since the decision feedback loop will effectively retrain and reinitialize due to the introduction of the generated pilot sequence into the feedback loop during each slot for correlation with the received pilot sequence.
While the present invention has been described in particular detail, it should also be appreciated that numerous modifications are possible within the intended spirit and scope of the invention. In interpreting the appended claims it should be understood that:
a) the word “comprising” does not exclude the presence of other elements or acts than those listed in a claim;
b) the word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.
c) any reference signs in the claims do not limit their scope; and
d) several “means” may be represented by the same item of hardware or software implemented structure or function.
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A decision feedback loop for a receiver for channel estimation and de-rotation of complex input symbols derived from a sampled information signal received via a channel which contains data organized into successive time slots, is configured to retrain and reinitialize the loop during each slot in order to mitigate slot to slot propagation of the estimation error.
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FIELD OF THE INVENTION
[0001] The field of this invention is refracturing and more particularly in wells originally fractured using bridge plugs and perforating guns sequentially deployed in a direction toward the surface where subsequent conditions after production dictate additional fracturing to be appropriate.
BACKGROUND OF THE INVENTION
[0002] In one known fracturing technique a perforating gun is run in on wireline above a composite bridge plug, typically in a long horizontal run in a cased wellbore. The plug is set and released from the bottom hole assembly and the perforating gun is moved far enough away from the plug to avoid damaging the plug before the gun is fired. The wireline is then retrieved and the well is stimulated. This process is repeated in a direction toward the surface with additional plugs and perforation services until the interval is finished having the perforations in place and stimulation treatments performed. Some time after stimulation, the composite bridge plugs are milled or drilled out and the production completion is installed and production starts.
[0003] At some point the production rate drops off or undesirable sand or water or other materials are produced and the decision is made that additional stimulation treatments are needed. The problem is that the entire payzone now has multiple sets of perforations, so isolation of one or more perforated sections without a significant decrease in flow area is difficult.
[0004] In the past ball sealers have been used that are pumped into a wellbore to isolate perforations that are producing undesirable materials. These barriers were meant to stay in position while production continued through other perforations. Ball sealers are described in U.S. Pat. Nos. 5,253,709; 5,309,995; 4,505,334 and 4,881,599. Also related to such sealing techniques are U.S. Pat. Nos. 7,380,600; 6,380,138; 5,990,051; 4,716,964; 7,775,278; 7,565,929; and 4,428,424 (plugging with cement that necessitates a refracture). US Publication 2010/0186297 uses fluids triggered to plug perforations with a magnetic field.
[0005] Coiled tubing run bottom hole assemblies that can isolate a portion of the wellbore for fluid delivery downhole are described in US Publication 20100126725.
[0006] More recently, controlled electrolytic materials have been described in US Publication 2011/0136707 and related applications filed the same day. The related applications are incorporated by reference herein as though fully set forth. The listed published application specification and drawings are literally included in this specification to provide an understanding of the materials considered to be encompassed by the term “controlled electrolytic materials.”
[0007] Lightweight, high-strength metallic materials are disclosed that may be used in a wide variety of applications and application environments, including use in various wellbore environments to make various selectably and controllably disposable or degradable lightweight, high-strength downhole tools or other downhole components, as well as many other applications for use in both durable and disposable or degradable articles. These lightweight, high-strength and selectably and controllably degradable materials include fully-dense, sintered powder compacts formed from coated powder materials that include various lightweight particle cores and core materials having various single layer and multilayer nanoscale coatings. These powder compacts are made from coated metallic powders that include various electrochemically-active (e.g., having relatively higher standard oxidation potentials) lightweight, high-strength particle cores and core materials, such as electrochemically active metals, that are dispersed within a cellular nanomatrix formed from the various nanoscale metallic coating layers of metallic coating materials, and are particularly useful in wellbore applications. These powder compacts provide a unique and advantageous combination of mechanical strength properties, such as compression and shear strength, low density and selectable and controllable corrosion properties, particularly rapid and controlled dissolution in various wellbore fluids. For example, the particle core and coating layers of these powders may be selected to provide sintered powder compacts suitable for use as high strength engineered materials having a compressive strength and shear strength comparable to various other engineered materials, including carbon, stainless and alloy steels, but which also have a low density comparable to various polymers, elastomers, low-density porous ceramics and composite materials. As yet another example, these powders and powder compact materials may be configured to provide a selectable and controllable degradation or disposal in response to a change in an environmental condition, such as a transition from a very low dissolution rate to a very rapid dissolution rate in response to a change in a property or condition of a wellbore proximate an article formed from the compact, including a property change in a wellbore fluid that is in contact with the powder compact. The selectable and controllable degradation or disposal characteristics described also allow the dimensional stability and strength of articles, such as wellbore tools or other components, made from these materials to be maintained until they are no longer needed, at which time a predetermined environmental condition, such as a wellbore condition, including wellbore fluid temperature, pressure or pH value, may be changed to promote their removal by rapid dissolution. These coated powder materials and powder compacts and engineered materials formed from them, as well as methods of making them, are described further below.
[0008] Referring to FIGS. 1-5 , a metallic powder 10 includes a plurality of metallic, coated powder particles 12 . Powder particles 12 may be formed to provide a powder 10 , including free-flowing powder, that may be poured or otherwise disposed in all manner of forms or molds (not shown) having all manner of shapes and sizes and that may be used to fashion precursor powder compacts 100 ( FIG. 16 ) and powder compacts 200 ( FIGS. 10-15 ), as described herein, that may be used as, or for use in manufacturing, various articles of manufacture, including various wellbore tools and components.
[0009] Each of the metallic, coated powder particles 12 of powder 10 includes a particle core 14 and a metallic coating layer 16 disposed on the particle core 14 . The particle core 14 includes a core material 18 . The core material 18 may include any suitable material for forming the particle core 14 that provides powder particle 12 that can be sintered to form a lightweight, high-strength powder compact 200 having selectable and controllable dissolution characteristics. Suitable core materials include electrochemically active metals having a standard oxidation potential greater than or equal to that of Zn, including as Mg, Al, Mn or Zn or a combination thereof. These electrochemically active metals are very reactive with a number of common wellbore fluids, including any number of ionic fluids or highly polar fluids, such as those that contain various chlorides. Examples include fluids comprising potassium chloride (KCl), hydrochloric acid (HCl), calcium chloride (CaCl 2 ), calcium bromide (CaBr 2 ) or zinc bromide (ZnBr 2 ). Core material 18 may also include other metals that are less electrochemically active than Zn or non-metallic materials, or a combination thereof. Suitable non-metallic materials include ceramics, composites, glasses or carbon, or a combination thereof. Core material 18 may be selected to provide a high dissolution rate in a predetermined wellbore fluid, but may also be selected to provide a relatively low dissolution rate, including zero dissolution, where dissolution of the nanomatrix material causes the particle core 14 to be rapidly undermined and liberated from the particle compact at the interface with the wellbore fluid, such that the effective rate of dissolution of particle compacts made using particle cores 14 of these core materials 18 is high, even though core material 18 itself may have a low dissolution rate, including core materials 20 that may be substantially insoluble in the wellbore fluid.
[0010] With regard to the electrochemically active metals as core materials 18 , including Mg, Al, Mn or Zn, these metals may be used as pure metals or in any combination with one another, including various alloy combinations of these materials, including binary, tertiary, or quaternary alloys of these materials. These combinations may also include composites of these materials. Further, in addition to combinations with one another, the Mg, Al, Mn or Zn core materials 18 may also include other constituents, including various alloying additions, to alter one or more properties of the particle cores 14 , such as by improving the strength, lowering the density or altering the dissolution characteristics of the core material 18 .
[0011] Among the electrochemically active metals, Mg, either as a pure metal or an alloy or a composite material, is particularly useful, because of its low density and ability to form high-strength alloys, as well as its high degree of electrochemical activity, since it has a standard oxidation potential higher than Al, Mn or Zn. Mg alloys include all alloys that have Mg as an alloy constituent. Mg alloys that combine other electrochemically active metals, as described herein, as alloy constituents are particularly useful, including binary Mg—Zn, Mg—Al and Mg—Mn alloys, as well as tertiary Mg—Zn—Y and Mg—Al—X alloys, where X includes Zn, Mn, Si, Ca or Y, or a combination thereof. These Mg—Al—X alloys may include, by weight, up to about 85% Mg, up to about 15% Al and up to about 5% X. Particle core 14 and core material 18 , and particularly electrochemically active metals including Mg, Al, Mn or Zn, or combinations thereof, may also include a rare earth element or combination of rare earth elements. As used herein, rare earth elements include Sc, Y, La, Ce, Pr, Nd or Er, or a combination of rare earth elements. Where present, a rare earth element or combinations of rare earth elements may be present, by weight, in an amount of about 5% or less.
[0012] Particle core 14 and core material 18 have a melting temperature (T P ). As used herein, T P includes the lowest temperature at which incipient melting or liquation or other forms of partial melting occur within core material 18 , regardless of whether core material 18 comprises a pure metal, an alloy with multiple phases having different melting temperatures or a composite of materials having different melting temperatures.
[0013] Particle cores 14 may have any suitable particle size or range of particle sizes or distribution of particle sizes. For example, the particle cores 14 may be selected to provide an average particle size that is represented by a normal or Gaussian type unimodal distribution around an average or mean, as illustrated generally in FIG. 1 . In another example, particle cores 14 may be selected or mixed to provide a multimodal distribution of particle sizes, including a plurality of average particle core sizes, such as, for example, a homogeneous bimodal distribution of average particle sizes, as illustrated generally and schematically in FIG. 6 . The selection of the distribution of particle core size may be used to determine, for example, the particle size and interparticle spacing 15 of the particles 12 of powder 10 . In an exemplary embodiment, the particle cores 14 may have a unimodal distribution and an average particle diameter of about 5 μm to about 300 μm, more particularly about 80 μm to about 120 μm, and even more particularly about 100 μm.
[0014] Particle cores 14 may have any suitable particle shape, including any regular or irregular geometric shape, or combination thereof. In an exemplary embodiment, particle cores 14 are substantially spheroidal electrochemically active metal particles. In another exemplary embodiment, particle cores 14 are substantially irregularly shaped ceramic particles. In yet another exemplary embodiment, particle cores 14 are carbon or other nanotube structures or hollow glass microspheres.
[0015] Each of the metallic, coated powder particles 12 of powder 10 also includes a metallic coating layer 16 that is disposed on particle core 14 . Metallic coating layer 16 includes a metallic coating material 20 . Metallic coating material 20 gives the powder particles 12 and powder 10 its metallic nature. Metallic coating layer 16 is a nanoscale coating layer. In an exemplary embodiment, metallic coating layer 16 may have a thickness of about 25 nm to about 2500 nm. The thickness of metallic coating layer 16 may vary over the surface of particle core 14 , but will preferably have a substantially uniform thickness over the surface of particle core 14 . Metallic coating layer 16 may include a single layer, as illustrated in FIG. 2 , or a plurality of layers as a multilayer coating structure, as illustrated in FIGS. 3-5 for up to four layers. In a single layer coating, or in each of the layers of a multilayer coating, the metallic coating layer 16 may include a single constituent chemical element or compound, or may include a plurality of chemical elements or compounds. Where a layer includes a plurality of chemical constituents or compounds, they may have all manner of homogeneous or heterogeneous distributions, including a homogeneous or heterogeneous distribution of metallurgical phases. This may include a graded distribution where the relative amounts of the chemical constituents or compounds vary according to respective constituent profiles across the thickness of the layer. In both single layer and multilayer coatings 16 , each of the respective layers, or combinations of them, may be used to provide a predetermined property to the powder particle 12 or a sintered powder compact formed therefrom. For example, the predetermined property may include the bond strength of the metallurgical bond between the particle core 14 and the coating material 20 ; the interdiffusion characteristics between the particle core 14 and metallic coating layer 16 , including any interdiffusion between the layers of a multilayer coating layer 16 ; the interdiffusion characteristics between the various layers of a multilayer coating layer 16 ; the interdiffusion characteristics between the metallic coating layer 16 of one powder particle and that of an adjacent powder particle 12 ; the bond strength of the metallurgical bond between the metallic coating layers of adjacent sintered powder particles 12 , including the outermost layers of multilayer coating layers; and the electrochemical activity of the coating layer 16 .
[0016] Metallic coating layer 16 and coating material 20 have a melting temperature (T C ). As used herein, T C includes the lowest temperature at which incipient melting or liquation or other forms of partial melting occur within coating material 20 , regardless of whether coating material 20 comprises a pure metal, an alloy with multiple phases each having different melting temperatures or a composite, including a composite comprising a plurality of coating material layers having different melting temperatures.
[0017] Metallic coating material 20 may include any suitable metallic coating material 20 that provides a sinterable outer surface 21 that is configured to be sintered to an adjacent powder particle 12 that also has a metallic coating layer 16 and sinterable outer surface 21 . In powders 10 that also include second or additional (coated or uncoated) particles 32 , as described herein, the sinterable outer surface 21 of metallic coating layer 16 is also configured to be sintered to a sinterable outer surface 21 of second particles 32 . In an exemplary embodiment, the powder particles 12 are sinterable at a predetermined sintering temperature (T S ) that is a function of the core material 18 and coating material 20 , such that sintering of powder compact 200 is accomplished entirely in the solid state and where T S is less than T P and T C . Sintering in the solid state limits particle core 14 /metallic coating layer 16 interactions to solid state diffusion processes and metallurgical transport phenomena and limits growth of and provides control over the resultant interface between them. In contrast, for example, the introduction of liquid phase sintering would provide for rapid interdiffusion of the particle core 14 /metallic coating layer 16 materials and make it difficult to limit the growth of and provide control over the resultant interface between them, and thus interfere with the formation of the desirable microstructure of particle compact 200 as described herein.
[0018] In an exemplary embodiment, core material 18 will be selected to provide a core chemical composition and the coating material 20 will be selected to provide a coating chemical composition and these chemical compositions will also be selected to differ from one another. In another exemplary embodiment, the core material 18 will be selected to provide a core chemical composition and the coating material 20 will be selected to provide a coating chemical composition and these chemical compositions will also be selected to differ from one another at their interface. Differences in the chemical compositions of coating material 20 and core material 18 may be selected to provide different dissolution rates and selectable and controllable dissolution of powder compacts 200 that incorporate them making them selectably and controllably dissolvable. This includes dissolution rates that differ in response to a changed condition in the wellbore, including an indirect or direct change in a wellbore fluid. In an exemplary embodiment, a powder compact 200 formed from powder 10 having chemical compositions of core material 18 and coating material 20 that make compact 200 is selectably dissolvable in a wellbore fluid in response to a changed wellbore condition that includes a change in temperature, change in pressure, change in flow rate, change in pH or change in chemical composition of the wellbore fluid, or a combination thereof. The selectable dissolution response to the changed condition may result from actual chemical reactions or processes that promote different rates of dissolution, but also encompass changes in the dissolution response that are associated with physical reactions or processes, such as changes in wellbore fluid pressure or flow rate.
[0019] In an exemplary embodiment of a powder 10 , particle core 14 includes Mg, Al, Mn or Zn, or a combination thereof, as core material 18 , and more particularly may include pure Mg and Mg alloys, and metallic coating layer 16 includes Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re, or Ni, or an oxide, nitride or a carbide thereof, or a combination of any of the aforementioned materials as coating material 20 .
[0020] In another exemplary embodiment of powder 10 , particle core 14 includes Mg, Al, Mn or Zn, or a combination thereof, as core material 18 , and more particularly may include pure Mg and Mg alloys, and metallic coating layer 16 includes a single layer of Al or Ni, or a combination thereof, as coating material 20 , as illustrated in FIG. 2 . Where metallic coating layer 16 includes a combination of two or more constituents, such as Al and Ni, the combination may include various graded or co-deposited structures of these materials where the amount of each constituent, and hence the composition of the layer, varies across the thickness of the layer, as also illustrated in FIG. 2 .
[0021] In yet another exemplary embodiment, particle core 14 includes Mg, Al, Mn or Zn, or a combination thereof, as core material 18 , and more particularly may include pure Mg and Mg alloys, and coating layer 16 includes two layers as core material 20 , as illustrated in FIG. 3 . The first layer 22 is disposed on the surface of particle core 14 and includes Al or Ni, or a combination thereof, as described herein. The second layer 24 is disposed on the surface of the first layer and includes Al, Zn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni or a combination thereof, and the first layer has a chemical composition that is different than the chemical composition of the second layer. In general, first layer 22 will be selected to provide a strong metallurgical bond to particle core 14 and to limit interdiffusion between the particle core 14 and coating layer 16 , particularly first layer 22 . Second layer 24 may be selected to increase the strength of the metallic coating layer 16 , or to provide a strong metallurgical bond and promote sintering with the second layer 24 of adjacent powder particles 12 , or both. In an exemplary embodiment, the respective layers of metallic coating layer 16 may be selected to promote the selective and controllable dissolution of the coating layer 16 in response to a change in a property of the wellbore, including the wellbore fluid, as described herein. However, this is only exemplary and it will be appreciated that other selection criteria for the various layers may also be employed. For example, any of the respective layers may be selected to promote the selective and controllable dissolution of the coating layer 16 in response to a change in a property of the wellbore, including the wellbore fluid, as described herein. Exemplary embodiments of a two-layer metallic coating layers 16 for use on particles cores 14 comprising Mg include first/second layer combinations comprising Al/Ni and Al/W.
[0022] In still another embodiment, particle core 14 includes Mg, Al, Mn or Zn, or a combination thereof, as core material 18 , and more particularly may include pure Mg and Mg alloys, and coating layer 16 includes three layers, as illustrated in FIG. 4 . The first layer 22 is disposed on particle core 14 and may include Al or Ni, or a combination thereof. The second layer 24 is disposed on first layer 22 and may include Al, Zn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, nitride or a carbide thereof, or a combination of any of the aforementioned second layer materials. The third layer 26 is disposed on the second layer 24 and may include Al, Mn, Fe, Co, Ni or a combination thereof. In a three-layer configuration, the composition of adjacent layers is different, such that the first layer has a chemical composition that is different than the second layer, and the second layer has a chemical composition that is different than the third layer. In an exemplary embodiment, first layer 22 may be selected to provide a strong metallurgical bond to particle core 14 and to limit interdiffusion between the particle core 14 and coating layer 16 , particularly first layer 22 . Second layer 24 may be selected to increase the strength of the metallic coating layer 16 , or to limit interdiffusion between particle core 14 or first layer 22 and outer or third layer 26 , or to promote adhesion and a strong metallurgical bond between third layer 26 and first layer 22 , or any combination of them. Third layer 26 may be selected to provide a strong metallurgical bond and promote sintering with the third layer 26 of adjacent powder particles 12 . However, this is only exemplary and it will be appreciated that other selection criteria for the various layers may also be employed. For example, any of the respective layers may be selected to promote the selective and controllable dissolution of the coating layer 16 in response to a change in a property of the wellbore, including the wellbore fluid, as described herein. An exemplary embodiment of a three-layer coating layer for use on particles cores comprising Mg include first/second/third layer combinations comprising Al/Al 2 O 3 /Al.
[0023] In still another embodiment, particle core 14 includes Mg, Al, Mn or Zn, or a combination thereof, as core material 18 , and more particularly may include pure Mg and Mg alloys, and coating layer 16 includes four layers, as illustrated in FIG. 5 . In the four layer configuration, the first layer 22 may include Al or Ni, or a combination thereof, as described herein. The second layer 24 may include Al, Zn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni or an oxide, nitride, carbide thereof, or a combination of the aforementioned second layer materials. The third layer 26 may also include Al, Zn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, nitride or carbide thereof, or a combination of any of the aforementioned third layer materials. The fourth layer 28 may include Al, Mn, Fe, Co, Ni or a combination thereof. In the four layer configuration, the chemical composition of adjacent layers is different, such that the chemical composition of first layer 22 is different than the chemical composition of second layer 24 , the chemical composition is of second layer 24 different than the chemical composition of third layer 26 , and the chemical composition of third layer 26 is different than the chemical composition of fourth layer 28 . In an exemplary embodiment, the selection of the various layers will be similar to that described for the three-layer configuration above with regard to the inner (first) and outer (fourth) layers, with the second and third layers available for providing enhanced interlayer adhesion, strength of the overall metallic coating layer 16 , limited interlayer diffusion or selectable and controllable dissolution, or a combination thereof. However, this is only exemplary and it will be appreciated that other selection criteria for the various layers may also be employed. For example, any of the respective layers may be selected to promote the selective and controllable dissolution of the coating layer 16 in response to a change in a property of the wellbore, including the wellbore fluid, as described herein.
[0024] The thickness of the various layers in multi-layer configurations may be apportioned between the various layers in any manner so long as the sum of the layer thicknesses provide a nanoscale coating layer 16 , including layer thicknesses as described herein. In one embodiment, the first layer 22 and outer layer ( 24 , 26 , or 28 depending on the number of layers) may be thicker than other layers, where present, due to the desire to provide sufficient material to promote the desired bonding of first layer 22 with the particle core 14 , or the bonding of the outer layers of adjacent powder particles 12 , during sintering of powder compact 200 .
[0025] Powder 10 may also include an additional or second powder 30 interspersed in the plurality of powder particles 12 , as illustrated in FIG. 7 . In an exemplary embodiment, the second powder 30 includes a plurality of second powder particles 32 . These second powder particles 32 may be selected to change a physical, chemical, mechanical or other property of a powder particle compact 200 formed from powder 10 and second powder 30 , or a combination of such properties. In an exemplary embodiment, the property change may include an increase in the compressive strength of powder compact 200 formed from powder 10 and second powder 30 . In another exemplary embodiment, the second powder 30 may be selected to promote the selective and controllable dissolution of in particle compact 200 formed from powder 10 and second powder 30 in response to a change in a property of the wellbore, including the wellbore fluid, as described herein. Second powder particles 32 may be uncoated or coated with a metallic coating layer 36 . When coated, including single layer or multilayer coatings, the coating layer 36 of second powder particles 32 may comprise the same coating material 40 as coating material 20 of powder particles 12 , or the coating material 40 may be different. The second powder particles 32 (uncoated) or particle cores 34 may include any suitable material to provide the desired benefit, including many metals. In an exemplary embodiment, when coated powder particles 12 comprising Mg, Al, Mn or Zn, or a combination thereof are employed, suitable second powder particles 32 may include Ni, W, Cu, Co or Fe, or a combination thereof. Since second powder particles 32 will also be configured for solid state sintering to powder particles 12 at the predetermined sintering temperature (T S ), particle cores 34 will have a melting temperature T AP and any coating layers 36 will have a second melting temperature T AC , where T S is less than T AP and T AC . It will also be appreciated that second powder 30 is not limited to one additional powder particle 32 type (i.e., a second powder particle), but may include a plurality of additional powder particles 32 (i.e., second, third, fourth, etc. types of additional powder particles 32 ) in any number.
[0026] Referring to FIG. 8 , an exemplary embodiment of a method 300 of making a metallic powder 10 is disclosed. Method 300 includes forming 310 a plurality of particle cores 14 as described herein. Method 300 also includes depositing 320 a metallic coating layer 16 on each of the plurality of particle cores 14 . Depositing 320 is the process by which coating layer 16 is disposed on particle core 14 as described herein.
[0027] Forming 310 of particle cores 14 may be performed by any suitable method for forming a plurality of particle cores 14 of the desired core material 18 , which essentially comprise methods of forming a powder of core material 18 . Suitable powder forming methods include mechanical methods; including machining, milling, impacting and other mechanical methods for forming the metal powder; chemical methods, including chemical decomposition, precipitation from a liquid or gas, solid-solid reactive synthesis and other chemical powder forming methods; atomization methods, including gas atomization, liquid and water atomization, centrifugal atomization, plasma atomization and other atomization methods for forming a powder; and various evaporation and condensation methods. In an exemplary embodiment, particle cores 14 comprising Mg may be fabricated using an atomization method, such as vacuum spray forming or inert gas spray forming.
[0028] Depositing 320 of metallic coating layers 16 on the plurality of particle cores 14 may be performed using any suitable deposition method, including various thin film deposition methods, such as, for example, chemical vapor deposition and physical vapor deposition methods. In an exemplary embodiment, depositing 320 of metallic coating layers 16 are performed using fluidized bed chemical vapor deposition (FBCVD). Depositing 320 of the metallic coating layers 16 by FBCVD includes flowing a reactive fluid as a coating medium that includes the desired metallic coating material 20 through a bed of particle cores 14 fluidized in a reactor vessel under suitable conditions, including temperature, pressure and flow rate conditions and the like, sufficient to induce a chemical reaction of the coating medium to produce the desired metallic coating material 20 and induce its deposition upon the surface of particle cores 14 to form coated powder particles 12 . The reactive fluid selected will depend upon the metallic coating material 20 desired, and will typically comprise an organometallic compound that includes the metallic material to be deposited, such as nickel tetracarbonyl (Ni(CO) 4 ), tungsten hexafluoride (WF 6 ), and triethyl aluminum (C 6 H 15 Al), that is transported in a carrier fluid, such as helium or argon gas. The reactive fluid, including carrier fluid, causes at least a portion of the plurality of particle cores 14 to be suspended in the fluid, thereby enabling the entire surface of the suspended particle cores 14 to be exposed to the reactive fluid, including, for example, a desired organometallic constituent, and enabling deposition of metallic coating material 20 and coating layer 16 over the entire surfaces of particle cores 14 such that they each become enclosed forming coated particles 12 having metallic coating layers 16 , as described herein. As also described herein, each metallic coating layer 16 may include a plurality of coating layers. Coating material 20 may be deposited in multiple layers to form a multilayer metallic coating layer 16 by repeating the step of depositing 320 described above and changing 330 the reactive fluid to provide the desired metallic coating material 20 for each subsequent layer, where each subsequent layer is deposited on the outer surface of particle cores 14 that already include any previously deposited coating layer or layers that make up metallic coating layer 16 . The metallic coating materials 20 of the respective layers (e.g., 22 , 24 , 26 , 28 , etc.) may be different from one another, and the differences may be provided by utilization of different reactive media that are configured to produce the desired metallic coating layers 16 on the particle cores 14 in the fluidize bed reactor.
[0029] As illustrated in FIGS. 1 and 9 , particle core 14 and core material 18 and metallic coating layer 16 and coating material 20 may be selected to provide powder particles 12 and a powder 10 that is configured for compaction and sintering to provide a powder compact 200 that is lightweight (i.e., having a relatively low density), high-strength and is selectably and controllably removable from a wellbore in response to a change in a wellbore property, including being selectably and controllably dissolvable in an appropriate wellbore fluid, including various wellbore fluids as disclosed herein. Powder compact 200 includes a substantially-continuous, cellular nanomatrix 216 of a nanomatrix material 220 having a plurality of dispersed particles 214 dispersed throughout the cellular nanomatrix 216 . The substantially-continuous cellular nanomatrix 216 and nanomatrix material 220 formed of sintered metallic coating layers 16 is formed by the compaction and sintering of the plurality of metallic coating layers 16 of the plurality of powder particles 12 . The chemical composition of nanomatrix material 220 may be different than that of coating material 20 due to diffusion effects associated with the sintering as described herein. Powder metal compact 200 also includes a plurality of dispersed particles 214 that comprise particle core material 218 . Dispersed particle cores 214 and core material 218 correspond to and are formed from the plurality of particle cores 14 and core material 18 of the plurality of powder particles 12 as the metallic coating layers 16 are sintered together to form nanomatrix 216 . The chemical composition of core material 218 may be different than that of core material 18 due to diffusion effects associated with sintering as described herein.
[0030] As used herein, the use of the term substantially-continuous cellular nanomatrix 216 does not connote the major constituent of the powder compact, but rather refers to the minority constituent or constituents, whether by weight or by volume. This is distinguished from most matrix composite materials where the matrix comprises the majority constituent by weight or volume. The use of the term substantially-continuous, cellular nanomatrix is intended to describe the extensive, regular, continuous and interconnected nature of the distribution of nanomatrix material 220 within powder compact 200 . As used herein, “substantially-continuous” describes the extension of the nanomatrix material throughout powder compact 200 such that it extends between and envelopes substantially all of the dispersed particles 214 . Substantially-continuous is used to indicate that complete continuity and regular order of the nanomatrix around each dispersed particle 214 is not required. For example, defects in the coating layer 16 over particle core 14 on some powder particles 12 may cause bridging of the particle cores 14 during sintering of the powder compact 200 , thereby causing localized discontinuities to result within the cellular nanomatrix 216 , even though in the other portions of the powder compact the nanomatrix is substantially continuous and exhibits the structure described herein. As used herein, “cellular” is used to indicate that the nanomatrix defines a network of generally repeating, interconnected, compartments or cells of nanomatrix material 220 that encompass and also interconnect the dispersed particles 214 . As used herein, “nanomatrix” is used to describe the size or scale of the matrix, particularly the thickness of the matrix between adjacent dispersed particles 214 . The metallic coating layers that are sintered together to form the nanomatrix are themselves nanoscale thickness coating layers. Since the nanomatrix at most locations, other than the intersection of more than two dispersed particles 214 , generally comprises the interdiffusion and bonding of two coating layers 16 from adjacent powder particles 12 having nanoscale thicknesses, the matrix formed also has a nanoscale thickness (e.g., approximately two times the coating layer thickness as described herein) and is thus described as a nanomatrix. Further, the use of the term dispersed particles 214 does not connote the minor constituent of powder compact 200 , but rather refers to the majority constituent or constituents, whether by weight or by volume. The use of the term dispersed particle is intended to convey the discontinuous and discrete distribution of particle core material 218 within powder compact 200 .
[0031] Powder compact 200 may have any desired shape or size, including that of a cylindrical billet or bar that may be machined or otherwise used to form useful articles of manufacture, including various wellbore tools and components. The pressing used to form precursor powder compact 100 and sintering and pressing processes used to form powder compact 200 and deform the powder particles 12 , including particle cores 14 and coating layers 16 , to provide the full density and desired macroscopic shape and size of powder compact 200 as well as its microstructure. The microstructure of powder compact 200 includes an equiaxed configuration of dispersed particles 214 that are dispersed throughout and embedded within the substantially-continuous, cellular nanomatrix 216 of sintered coating layers. This microstructure is somewhat analogous to an equiaxed grain microstructure with a continuous grain boundary phase, except that it does not require the use of alloy constituents having thermodynamic phase equilibria properties that are capable of producing such a structure. Rather, this equiaxed dispersed particle structure and cellular nanomatrix 216 of sintered metallic coating layers 16 may be produced using constituents where thermodynamic phase equilibrium conditions would not produce an equiaxed structure. The equiaxed morphology of the dispersed particles 214 and cellular network 216 of particle layers results from sintering and deformation of the powder particles 12 as they are compacted and interdiffuse and deform to fill the interparticle spaces 15 ( FIG. 1 ). The sintering temperatures and pressures may be selected to ensure that the density of powder compact 200 achieves substantially full theoretical density.
[0032] In an exemplary embodiment as illustrated in FIGS. 1 and 9 , dispersed particles 214 are formed from particle cores 14 dispersed in the cellular nanomatrix 216 of sintered metallic coating layers 16 , and the nanomatrix 216 includes a solid-state metallurgical bond 217 or bond layer 219 , as illustrated schematically in FIG. 10 , extending between the dispersed particles 214 throughout the cellular nanomatrix 216 that is formed at a sintering temperature (T S ), where T S is less than T C and T P . As indicated, solid-state metallurgical bond 217 is formed in the solid state by solid-state interdiffusion between the coating layers 16 of adjacent powder particles 12 that are compressed into touching contact during the compaction and sintering processes used to form powder compact 200 , as described herein. As such, sintered coating layers 16 of cellular nanomatrix 216 include a solid-state bond layer 219 that has a thickness (t) defined by the extent of the interdiffusion of the coating materials 20 of the coating layers 16 , which will in turn be defined by the nature of the coating layers 16 , including whether they are single or multilayer coating layers, whether they have been selected to promote or limit such interdiffusion, and other factors, as described herein, as well as the sintering and compaction conditions, including the sintering time, temperature and pressure used to form powder compact 200 .
[0033] As nanomatrix 216 is formed, including bond 217 and bond layer 219 , the chemical composition or phase distribution, or both, of metallic coating layers 16 may change. Nanomatrix 216 also has a melting temperature (T M ). As used herein, T M includes the lowest temperature at which incipient melting or liquation or other forms of partial melting will occur within nanomatrix 216 , regardless of whether nanomatrix material 220 comprises a pure metal, an alloy with multiple phases each having different melting temperatures or a composite, including a composite comprising a plurality of layers of various coating materials having different melting temperatures, or a combination thereof, or otherwise. As dispersed particles 214 and particle core materials 218 are formed in conjunction with nanomatrix 216 , diffusion of constituents of metallic coating layers 16 into the particle cores 14 is also possible, which may result in changes in the chemical composition or phase distribution, or both, of particle cores 14 . As a result, dispersed particles 214 and particle core materials 218 may have a melting temperature (T DP ) that is different than T P As used herein, T DP includes the lowest temperature at which incipient melting or liquation or other forms of partial melting will occur within dispersed particles 214 , regardless of whether particle core material 218 comprise a pure metal, an alloy with multiple phases each having different melting temperatures or a composite, or otherwise. Powder compact 200 is formed at a sintering temperature (T S ), where T S is less than T C , T P , T M and T DP . Dispersed particles 214 may comprise any of the materials described herein for particle cores 14 , even though the chemical composition of dispersed particles 214 may be different due to diffusion effects as described herein. In an exemplary embodiment, dispersed particles 214 are formed from particle cores 14 comprising materials having a standard oxidation potential greater than or equal to Zn, including Mg, Al, Zn or Mn, or a combination thereof, may include various binary, tertiary and quaternary alloys or other combinations of these constituents as disclosed herein in conjunction with particle cores 14 . Of these materials, those having dispersed particles 214 comprising Mg and the nanomatrix 216 formed from the metallic coating materials 16 described herein are particularly useful. Dispersed particles 214 and particle core material 218 of Mg, Al, Zn or Mn, or a combination thereof, may also include a rare earth element, or a combination of rare earth elements as disclosed herein in conjunction with particle cores 14 .
[0034] In another exemplary embodiment, dispersed particles 214 are formed from particle cores 14 comprising metals that are less electrochemically active than Zn or non-metallic materials. Suitable non-metallic materials include ceramics, glasses (e.g., hollow glass microspheres) or carbon, or a combination thereof, as described herein.
[0035] Dispersed particles 214 of powder compact 200 may have any suitable particle size, including the average particle sizes described herein for particle cores 14 .
[0036] Dispersed particles 214 may have any suitable shape depending on the shape selected for particle cores 14 and powder particles 12 , as well as the method used to sinter and compact powder 10 . In an exemplary embodiment, powder particles 12 may be spheroidal or substantially spheroidal and dispersed particles 214 may include an equiaxed particle configuration as described herein.
[0037] The nature of the dispersion of dispersed particles 214 may be affected by the selection of the powder 10 or powders 10 used to make particle compact 200 . In one exemplary embodiment, a powder 10 having a unimodal distribution of powder particle 12 sizes may be selected to form powder compact 200 and will produce a substantially homogeneous unimodal dispersion of particle sizes of dispersed particles 214 within cellular nanomatrix 216 , as illustrated generally in FIG. 9 . In another exemplary embodiment, a plurality of powders 10 having a plurality of powder particles with particle cores 14 that have the same core materials 18 and different core sizes and the same coating material 20 may be selected and uniformly mixed as described herein to provide a powder 10 having a homogenous, multimodal distribution of powder particle 12 sizes, and may be used to form powder compact 200 having a homogeneous, multimodal dispersion of particle sizes of dispersed particles 214 within cellular nanomatrix 216 , as illustrated schematically in FIGS. 6 and 11 . Similarly, in yet another exemplary embodiment, a plurality of powders 10 having a plurality of particle cores 14 that may have the same core materials 18 and different core sizes and the same coating material 20 may be selected and distributed in a non-uniform manner to provide a non-homogenous, multimodal distribution of powder particle sizes, and may be used to form powder compact 200 having a non-homogeneous, multimodal dispersion of particle sizes of dispersed particles 214 within cellular nanomatrix 216 , as illustrated schematically in FIG. 12 . The selection of the distribution of particle core size may be used to determine, for example, the particle size and interparticle spacing of the dispersed particles 214 within the cellular nanomatrix 216 of powder compacts 200 made from powder 10 .
[0038] As illustrated generally in FIGS. 7 and 13 , powder metal compact 200 may also be formed using coated metallic powder 10 and an additional or second powder 30 , as described herein. The use of an additional powder 30 provides a powder compact 200 that also includes a plurality of dispersed second particles 234 , as described herein, that are dispersed within the nanomatrix 216 and are also dispersed with respect to the dispersed particles 214 . Dispersed second particles 234 may be formed from coated or uncoated second powder particles 32 , as described herein. In an exemplary embodiment, coated second powder particles 32 may be coated with a coating layer 36 that is the same as coating layer 16 of powder particles 12 , such that coating layers 36 also contribute to the nanomatrix 216 . In another exemplary embodiment, the second powder particles 232 may be uncoated such that dispersed second particles 234 are embedded within nanomatrix 216 . As disclosed herein, powder 10 and additional powder 30 may be mixed to form a homogeneous dispersion of dispersed particles 214 and dispersed second particles 234 , as illustrated in FIG. 13 , or to form a non-homogeneous dispersion of these particles, as illustrated in FIG. 14 . The dispersed second particles 234 may be formed from any suitable additional powder 30 that is different from powder 10 , either due to a compositional difference in the particle core 34 , or coating layer 36 , or both of them, and may include any of the materials disclosed herein for use as second powder 30 that are different from the powder 10 that is selected to form powder compact 200 . In an exemplary embodiment, dispersed second particles 234 may include Fe, Ni, Co or Cu, or oxides, nitrides or carbides thereof, or a combination of any of the aforementioned materials.
[0039] Nanomatrix 216 is a substantially-continuous, cellular network of metallic coating layers 16 that are sintered to one another. The thickness of nanomatrix 216 will depend on the nature of the powder 10 or powders 10 used to form powder compact 200 , as well as the incorporation of any second powder 30 , particularly the thicknesses of the coating layers associated with these particles. In an exemplary embodiment, the thickness of nanomatrix 216 is substantially uniform throughout the microstructure of powder compact 200 and comprises about two times the thickness of the coating layers 16 of powder particles 12 . In another exemplary embodiment, the cellular network 216 has a substantially uniform average thickness between dispersed particles 214 of about 50 nm to about 5000 nm.
[0040] Nanomatrix 216 is formed by sintering metallic coating layers 16 of adjacent particles to one another by interdiffusion and creation of bond layer 219 as described herein. Metallic coating layers 16 may be single layer or multilayer structures, and they may be selected to promote or inhibit diffusion, or both, within the layer or between the layers of metallic coating layer 16 , or between the metallic coating layer 16 and particle core 14 , or between the metallic coating layer 16 and the metallic coating layer 16 of an adjacent powder particle, the extent of interdiffusion of metallic coating layers 16 during sintering may be limited or extensive depending on the coating thicknesses, coating material or materials selected, the sintering conditions and other factors. Given the potential complexity of the interdiffusion and interaction of the constituents, description of the resulting chemical composition of nanomatrix 216 and nanomatrix material 220 may be simply understood to be a combination of the constituents of coating layers 16 that may also include one or more constituents of dispersed particles 214 , depending on the extent of interdiffusion, if any, that occurs between the dispersed particles 214 and the nanomatrix 216 . Similarly, the chemical composition of dispersed particles 214 and particle core material 218 may be simply understood to be a combination of the constituents of particle core 14 that may also include one or more constituents of nanomatrix 216 and nanomatrix material 220 , depending on the extent of interdiffusion, if any, that occurs between the dispersed particles 214 and the nanomatrix 216 .
[0041] In an exemplary embodiment, the nanomatrix material 220 has a chemical composition and the particle core material 218 has a chemical composition that is different from that of nanomatrix material 220 , and the differences in the chemical compositions may be configured to provide a selectable and controllable dissolution rate, including a selectable transition from a very low dissolution rate to a very rapid dissolution rate, in response to a controlled change in a property or condition of the wellbore proximate the compact 200 , including a property change in a wellbore fluid that is in contact with the powder compact 200 , as described herein. Nanomatrix 216 may be formed from powder particles 12 having single layer and multilayer coating layers 16 . This design flexibility provides a large number of material combinations, particularly in the case of multilayer coating layers 16 , that can be utilized to tailor the cellular nanomatrix 216 and composition of nanomatrix material 220 by controlling the interaction of the coating layer constituents, both within a given layer, as well as between a coating layer 16 and the particle core 14 with which it is associated or a coating layer 16 of an adjacent powder particle 12 . Several exemplary embodiments that demonstrate this flexibility are provided below.
[0042] As illustrated in FIG. 10 , in an exemplary embodiment, powder compact 200 is formed from powder particles 12 where the coating layer 16 comprises a single layer, and the resulting nanomatrix 216 between adjacent ones of the plurality of dispersed particles 214 comprises the single metallic coating layer 16 of one powder particle 12 , a bond layer 219 and the single coating layer 16 of another one of the adjacent powder particles 12 . The thickness (t) of bond layer 219 is determined by the extent of the interdiffusion between the single metallic coating layers 16 , and may encompass the entire thickness of nanomatrix 216 or only a portion thereof. In one exemplary embodiment of powder compact 200 formed using a single layer powder 10 , powder compact 200 may include dispersed particles 214 comprising Mg, Al, Zn or Mn, or a combination thereof, as described herein, and nanomatrix 216 may include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, carbide or nitride thereof, or a combination of any of the aforementioned materials, including combinations where the nanomatrix material 220 of cellular nanomatrix 216 , including bond layer 219 , has a chemical composition and the core material 218 of dispersed particles 214 has a chemical composition that is different than the chemical composition of nanomatrix material 216 . The difference in the chemical composition of the nanomatrix material 220 and the core material 218 may be used to provide selectable and controllable dissolution in response to a change in a property of a wellbore, including a wellbore fluid, as described herein. In a further exemplary embodiment of a powder compact 200 formed from a powder 10 having a single coating layer configuration, dispersed particles 214 include Mg, Al, Zn or Mn, or a combination thereof, and the cellular nanomatrix 216 includes Al or Ni, or a combination thereof.
[0043] As illustrated in FIG. 15 , in another exemplary embodiment, powder compact 200 is formed from powder particles 12 where the coating layer 16 comprises a multilayer coating layer 16 having a plurality of coating layers, and the resulting nanomatrix 216 between adjacent ones of the plurality of dispersed particles 214 comprises the plurality of layers (t) comprising the coating layer 16 of one particle 12 , a bond layer 219 , and the plurality of layers comprising the coating layer 16 of another one of powder particles 12 . In FIG. 15 , this is illustrated with a two-layer metallic coating layer 16 , but it will be understood that the plurality of layers of multi-layer metallic coating layer 16 may include any desired number of layers. The thickness (t) of the bond layer 219 is again determined by the extent of the interdiffusion between the plurality of layers of the respective coating layers 16 , and may encompass the entire thickness of nanomatrix 216 or only a portion thereof. In this embodiment, the plurality of layers comprising each coating layer 16 may be used to control interdiffusion and formation of bond layer 219 and thickness (t).
[0044] In one exemplary embodiment of a powder compact 200 made using powder particles 12 with multilayer coating layers 16 , the compact includes dispersed particles 214 comprising Mg, Al, Zn or Mn, or a combination thereof, as described herein, and nanomatrix 216 comprises a cellular network of sintered two-layer coating layers 16 , as shown in FIG. 3 , comprising first layers 22 that are disposed on the dispersed particles 214 and a second layers 24 that are disposed on the first layers 22 . First layers 22 include Al or Ni, or a combination thereof, and second layers 24 include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or a combination thereof. In these configurations, materials of dispersed particles 214 and multilayer coating layer 16 used to form nanomatrix 216 are selected so that the chemical compositions of adjacent materials are different (e.g. dispersed particle/first layer and first layer/second layer).
[0045] In another exemplary embodiment of a powder compact 200 made using powder particles 12 with multilayer coating layers 16 , the compact includes dispersed particles 214 comprising Mg, Al, Zn or Mn, or a combination thereof, as described herein, and nanomatrix 216 comprises a cellular network of sintered three-layer metallic coating layers 16 , as shown in FIG. 4 , comprising first layers 22 that are disposed on the dispersed particles 214 , second layers 24 that are disposed on the first layers 22 and third layers 26 that are disposed on the second layers 24 . First layers 22 include Al or Ni, or a combination thereof; second layers 24 include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, nitride or carbide thereof, or a combination of any of the aforementioned second layer materials; and the third layers include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or a combination thereof. The selection of materials is analogous to the selection considerations described herein for powder compact 200 made using two-layer coating layer powders, but must also be extended to include the material used for the third coating layer.
[0046] In yet another exemplary embodiment of a powder compact 200 made using powder particles 12 with multilayer coating layers 16 , the compact includes dispersed particles 214 comprising Mg, Al, Zn or Mn, or a combination thereof, as described herein, and nanomatrix 216 comprise a cellular network of sintered four-layer coating layers 16 comprising first layers 22 that are disposed on the dispersed particles 214 ; second layers 24 that are disposed on the first layers 22 ; third layers 26 that are disposed on the second layers 24 and fourth layers 28 that are disposed on the third layers 26 . First layers 22 include Al or Ni, or a combination thereof; second layers 24 include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, nitride or carbide thereof, or a combination of any of the aforementioned second layer materials; third layers include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, nitride or carbide thereof, or a combination of any of the aforementioned third layer materials; and fourth layers include Al, Mn, Fe, Co or Ni, or a combination thereof. The selection of materials is analogous to the selection considerations described herein for powder compacts 200 made using two-layer coating layer powders, but must also be extended to include the material used for the third and fourth coating layers.
[0047] In another exemplary embodiment of a powder compact 200 , dispersed particles 214 comprise a metal having a standard oxidation potential less than Zn or a non-metallic material, or a combination thereof, as described herein, and nanomatrix 216 comprises a cellular network of sintered metallic coating layers 16 . Suitable non-metallic materials include various ceramics, glasses or forms of carbon, or a combination thereof. Further, in powder compacts 200 that include dispersed particles 214 comprising these metals or non-metallic materials, nanomatrix 216 may include Al, Zn, Mn, Mg, Mo, W, Cu, Fe, Si, Ca, Co, Ta, Re or Ni, or an oxide, carbide or nitride thereof, or a combination of any of the aforementioned materials as nanomatrix material 220 .
[0048] Referring to FIG. 16 , sintered powder compact 200 may comprise a sintered precursor powder compact 100 that includes a plurality of deformed, mechanically bonded powder particles as described herein. Precursor powder compact 100 may be formed by compaction of powder 10 to the point that powder particles 12 are pressed into one another, thereby deforming them and forming interparticle mechanical or other bonds 110 associated with this deformation sufficient to cause the deformed powder particles 12 to adhere to one another and form a green-state powder compact having a green density that is less than the theoretical density of a fully-dense compact of powder 10 , due in part to interparticle spaces 15 . Compaction may be performed, for example, by is statically pressing powder 10 at room temperature to provide the deformation and interparticle bonding of powder particles 12 necessary to form precursor powder compact 100 .
[0049] Sintered and forged powder compacts 200 that include dispersed particles 214 comprising Mg and nanomatrix 216 comprising various nanomatrix materials as described herein have demonstrated an excellent combination of mechanical strength and low density that exemplify the lightweight, high-strength materials disclosed herein. Examples of powder compacts 200 that have pure Mg dispersed particles 214 and various nanomatrices 216 formed from powders 10 having pure Mg particle cores 14 and various single and multilayer metallic coating layers 16 that include Al, Ni, W or Al 2 O 3 , or a combination thereof, and that have been made using the method 400 disclosed herein, are listed in a table as FIG. 18 . These powders compacts 200 have been subjected to various mechanical and other testing, including density testing, and their dissolution and mechanical property degradation behavior has also been characterized as disclosed herein. The results indicate that these materials may be configured to provide a wide range of selectable and controllable corrosion or dissolution behavior from very low corrosion rates to extremely high corrosion rates, particularly corrosion rates that are both lower and higher than those of powder compacts that do not incorporate the cellular nanomatrix, such as a compact formed from pure Mg powder through the same compaction and sintering processes in comparison to those that include pure Mg dispersed particles in the various cellular nanomatrices described herein. These powder compacts 200 may also be configured to provide substantially enhanced properties as compared to powder compacts formed from pure Mg particles that do not include the nanoscale coatings described herein. For example, referring to FIGS. 18 and 19 , powder compacts 200 that include dispersed particles 214 comprising Mg and nanomatrix 216 comprising various nanomatrix materials 220 described herein have demonstrated a room temperature compressive strengths of at least about 37 ksi, and have further demonstrated room temperature compressive strengths in excess of about 50 ksi, both dry and immersed in a solution of 3% KCl at 200° F. In contrast, powder compacts formed from pure Mg powders have a compressive strength of about 20 ksi or less. Strength of the nanomatrix powder metal compact 200 can be further improved by optimizing powder 10 , particularly the weight percentage of the nanoscale metallic coating layers 16 that are used to form cellular nanomatrix 216 . For example, FIG. 25 shows the effect of varying the weight percentage (wt. %), i.e., thickness, of an alumina coating on the room temperature compressive strength of a powder compact 200 of a cellular nanomatrix 216 formed from coated powder particles 12 that include a multilayer (Al/Al 2 O 3 /Al) metallic coating layer 16 on pure Mg particle cores 14 . In this example, optimal strength is achieved at 4 wt % of alumina, which represents an increase of 21% as compared to that of 0 wt % alumina.
[0050] Powder compacts 200 comprising dispersed particles 214 that include Mg and nanomatrix 216 that includes various nanomatrix materials as described herein have also demonstrated a room temperature sheer strength of at least about 20 ksi. This is in contrast with powder compacts formed from pure Mg powders which have room temperature sheer strengths of about 8 ksi.
[0051] Powder compacts 200 of the types disclosed herein are able to achieve an actual density that is substantially equal to the predetermined theoretical density of a compact material based on the composition of powder 10 , including relative amounts of constituents of particle cores 14 and metallic coating layer 16 , and are also described herein as being fully-dense powder compacts. Powder compacts 200 comprising dispersed particles that include Mg and nanomatrix 216 that includes various nanomatrix materials as described herein have demonstrated actual densities of about 1.738 g/cm 3 to about 2.50 g/cm 3 , which are substantially equal to the predetermined theoretical densities, differing by at most 4% from the predetermined theoretical densities.
[0052] Powder compacts 200 as disclosed herein may be configured to be selectively and controllably dissolvable in a wellbore fluid in response to a changed condition in a wellbore. Examples of the changed condition that may be exploited to provide selectable and controllable dissolvability include a change in temperature, change in pressure, change in flow rate, change in pH or change in chemical composition of the wellbore fluid, or a combination thereof. An example of a changed condition comprising a change in temperature includes a change in well bore fluid temperature. For example, referring to FIGS. 18 and 20 , powder compacts 200 comprising dispersed particles 214 that include Mg and cellular nanomatrix 216 that includes various nanomatrix materials as described herein have relatively low rates of corrosion in a 3% KCl solution at room temperature that ranges from about 0 to about 11 mg/cm 2 /hr as compared to relatively high rates of corrosion at 200° F. that range from about 1 to about 246 mg/cm 2 /hr depending on different nanoscale coating layers 16 . An example of a changed condition comprising a change in chemical composition includes a change in a chloride ion concentration or pH value, or both, of the wellbore fluid. For example, referring to FIGS. 18 and 21 , powder compacts 200 comprising dispersed particles 214 that include Mg and nanomatrix 216 that includes various nanoscale coatings described herein demonstrate corrosion rates in 15% HCl that range from about 4750 mg/cm 2 /hr to about 7432 mg/cm 2 /hr. Thus, selectable and controllable dissolvability in response to a changed condition in the wellbore, namely the change in the wellbore fluid chemical composition from KCl to HCl, may be used to achieve a characteristic response as illustrated graphically in FIG. 22 , which illustrates that at a selected predetermined critical service time (CST) a changed condition may be imposed upon powder compact 200 as it is applied in a given application, such as a wellbore environment, that causes a controllable change in a property of powder compact 200 in response to a changed condition in the environment in which it is applied. For example, at a predetermined CST changing a wellbore fluid that is in contact with powder contact 200 from a first fluid (e.g. KCl) that provides a first corrosion rate and an associated weight loss or strength as a function of time to a second wellbore fluid (e.g., HCl) that provides a second corrosion rate and associated weight loss and strength as a function of time, wherein the corrosion rate associated with the first fluid is much less than the corrosion rate associated with the second fluid. This characteristic response to a change in wellbore fluid conditions may be used, for example, to associate the critical service time with a dimension loss limit or a minimum strength needed for a particular application, such that when a wellbore tool or component formed from powder compact 200 as disclosed herein is no longer needed in service in the wellbore (e.g., the CST) the condition in the wellbore (e.g., the chloride ion concentration of the wellbore fluid) may be changed to cause the rapid dissolution of powder compact 200 and its removal from the wellbore. In the example described above, powder compact 200 is selectably dissolvable at a rate that ranges from about 0 to about 7000 mg/cm 2 /hr. This range of response provides, for example the ability to remove a 3 inch diameter ball formed from this material from a wellbore by altering the wellbore fluid in less than one hour. The selectable and controllable dissolvability behavior described above, coupled with the excellent strength and low density properties described herein, define a new engineered dispersed particle-nanomatrix material that is configured for contact with a fluid and configured to provide a selectable and controllable transition from one of a first strength condition to a second strength condition that is lower than a functional strength threshold, or a first weight loss amount to a second weight loss amount that is greater than a weight loss limit, as a function of time in contact with the fluid. The dispersed particle-nanomatrix composite is characteristic of the powder compacts 200 described herein and includes a cellular nanomatrix 216 of nanomatrix material 220 , a plurality of dispersed particles 214 including particle core material 218 that is dispersed within the matrix. Nanomatrix 216 is characterized by a solid-state bond layer 219 which extends throughout the nanomatrix. The time in contact with the fluid described above may include the CST as described above. The CST may include a predetermined time that is desired or required to dissolve a predetermined portion of the powder compact 200 that is in contact with the fluid. The CST may also include a time corresponding to a change in the property of the engineered material or the fluid, or a combination thereof. In the case of a change of property of the engineered material, the change may include a change of a temperature of the engineered material. In the case where there is a change in the property of the fluid, the change may include the change in a fluid temperature, pressure, flow rate, chemical composition or pH or a combination thereof. Both the engineered material and the change in the property of the engineered material or the fluid, or a combination thereof, may be tailored to provide the desired CST response characteristic, including the rate of change of the particular property (e.g., weight loss, loss of strength) both prior to the CST (e.g., Stage 1 ) and after the CST (e.g., Stage 2 ), as illustrated in FIG. 22 .
[0053] Referring to FIG. 17 , a method 400 of making a powder compact 200 is described. Method 400 includes forming 410 a coated metallic powder 10 comprising powder particles 12 having particle cores 14 with nanoscale metallic coating layers 16 disposed thereon, wherein the metallic coating layers 16 have a chemical composition and the particle cores 14 have a chemical composition that is different than the chemical composition of the metallic coating material 16 . Method 400 also includes forming 420 a powder compact by applying a predetermined temperature and a predetermined pressure to the coated powder particles sufficient to sinter them by solid-phase sintering of the coated layers of the plurality of the coated particle powders 12 to form a substantially-continuous, cellular nanomatrix 216 of a nanomatrix material 220 and a plurality of dispersed particles 214 dispersed within nanomatrix 216 as described herein.
[0054] Forming 410 of coated metallic powder 10 comprising powder particles 12 having particle cores 14 with nanoscale metallic coating layers 16 disposed thereon may be performed by any suitable method. In an exemplary embodiment, forming 410 includes applying the metallic coating layers 16 , as described herein, to the particle cores 14 , as described herein, using fluidized bed chemical vapor deposition (FBCVD) as described herein. Applying the metallic coating layers 16 may include applying single-layer metallic coating layers 16 or multilayer metallic coating layers 16 as described herein. Applying the metallic coating layers 16 may also include controlling the thickness of the individual layers as they are being applied, as well as controlling the overall thickness of metallic coating layers 16 . Particle cores 14 may be formed as described herein.
[0055] Forming 420 of the powder compact 200 may include any suitable method of forming a fully-dense compact of powder 10 . In an exemplary embodiment, forming 420 includes dynamic forging of a green-density precursor powder compact 100 to apply a predetermined temperature and a predetermined pressure sufficient to sinter and deform the powder particles and form a fully-dense nanomatrix 216 and dispersed particles 214 as described herein. Dynamic forging as used herein means dynamic application of a load at temperature and for a time sufficient to promote sintering of the metallic coating layers 16 of adjacent powder particles 12 , and may preferably include application of a dynamic forging load at a predetermined loading rate for a time and at a temperature sufficient to form a sintered and fully-dense powder compact 200 . In an exemplary embodiment, dynamic forging included: 1) heating a precursor or green-state powder compact 100 to a predetermined solid phase sintering temperature, such as, for example, a temperature sufficient to promote interdiffusion between metallic coating layers 16 of adjacent powder particles 12 ; 2) holding the precursor powder compact 100 at the sintering temperature for a predetermined hold time, such as, for example, a time sufficient to ensure substantial uniformity of the sintering temperature throughout the precursor compact 100 ; 3) forging the precursor powder compact 100 to full density, such as, for example, by applying a predetermined forging pressure according to a predetermined pressure schedule or ramp rate sufficient to rapidly achieve full density while holding the compact at the predetermined sintering temperature; and 4) cooling the compact to room temperature. The predetermined pressure and predetermined temperature applied during forming 420 will include a sintering temperature, T S , and forging pressure, P F , as described herein that will ensure solid-state sintering and deformation of the powder particles 12 to form fully-dense powder compact 200 , including solid-state bond 217 and bond layer 219 . The steps of heating to and holding the precursor powder compact 100 at the predetermined sintering temperature for the predetermined time may include any suitable combination of temperature and time, and will depend, for example, on the powder 10 selected, including the materials used for particle core 14 and metallic coating layer 16 , the size of the precursor powder compact 100 , the heating method used and other factors that influence the time needed to achieve the desired temperature and temperature uniformity within precursor powder compact 100 . In the step of forging, the predetermined pressure may include any suitable pressure and pressure application schedule or pressure ramp rate sufficient to achieve a fully-dense powder compact 200 , and will depend, for example, on the material properties of the powder particles 12 selected, including temperature dependent stress/strain characteristics (e.g., stress/strain rate characteristics), interdiffusion and metallurgical thermodynamic and phase equilibria characteristics, dislocation dynamics and other material properties. For example, the maximum forging pressure of dynamic forging and the forging schedule (i.e., the pressure ramp rates that correspond to strain rates employed) may be used to tailor the mechanical strength and toughness of the powder compact. The maximum forging pressure and forging ramp rate (i.e., strain rate) is the pressure just below the compact cracking pressure, i.e., where dynamic recovery processes are unable to relieve strain energy in the compact microstructure without the formation of a crack in the compact. For example, for applications that require a powder compact that has relatively higher strength and lower toughness, relatively higher forging pressures and ramp rates may be used. If relatively higher toughness of the powder compact is needed, relatively lower forging pressures and ramp rates may be used.
[0056] For certain exemplary embodiments of powders 10 described herein and precursor compacts 100 of a size sufficient to form many wellbore tools and components, predetermined hold times of about 1 to about 5 hours may be used. The predetermined sintering temperature, T S , will preferably be selected as described herein to avoid melting of either particle cores 14 or metallic coating layers 16 as they are transformed during method 400 to provide dispersed particles 214 and nanomatrix 216 . For these embodiments, dynamic forging may include application of a forging pressure, such as by dynamic pressing to a maximum of about 80 ksi at pressure ramp rate of about 0.5 to about 2 ksi/second.
[0057] In an exemplary embodiment where particle cores 14 included Mg and metallic coating layer 16 included various single and multilayer coating layers as described herein, such as various single and multilayer coatings comprising Al, the dynamic forging was performed by sintering at a temperature, T S , of about 450° C. to about 470° C. for up to about 1 hour without the application of a forging pressure, followed by dynamic forging by application of isostatic pressures at ramp rates between about 0.5 to about 2 ksi/second to a maximum pressure, P S , of about 30 ksi to about 60 ksi, which resulted in forging cycles of 15 seconds to about 120 seconds. The short duration of the forging cycle is a significant advantage as it limits interdiffusion, including interdiffusion within a given metallic coating layer 16 , interdiffusion between adjacent metallic coating layers 16 and interdiffusion between metallic coating layers 16 and particle cores 14 , to that needed to form metallurgical bond 217 and bond layer 219 , while also maintaining the desirable equiaxed dispersed particle 214 shape with the integrity of cellular nanomatrix 216 strengthening phase. The duration of the dynamic forging cycle is much shorter than the forming cycles and sintering times required for conventional powder compact forming processes, such as hot isostatic pressing (HIP), pressure assisted sintering or diffusion sintering.
[0058] Method 400 may also optionally include forming 430 a precursor powder compact by compacting the plurality of coated powder particles 12 sufficiently to deform the particles and form interparticle bonds to one another and form the precursor powder compact 100 prior to forming 420 the powder compact. Compacting may include pressing, such as isostatic pressing, of the plurality of powder particles 12 at room temperature to form precursor powder compact 100 . Compacting 430 may be performed at room temperature. In an exemplary embodiment, powder 10 may include particle cores 14 comprising Mg and forming 430 the precursor powder compact may be performed at room temperature at an isostatic pressure of about 10 ksi to about 60 ksi.
[0059] Method 400 may optionally also include intermixing 440 a second powder 30 into powder 10 as described herein prior to the forming 420 the powder compact, or forming 430 the precursor powder compact.
[0060] Without being limited by theory, powder compacts 200 are formed from coated powder particles 12 that include a particle core 14 and associated core material 18 as well as a metallic coating layer 16 and an associated metallic coating material 20 to form a substantially-continuous, three-dimensional, cellular nanomatrix 216 that includes a nanomatrix material 220 formed by sintering and the associated diffusion bonding of the respective coating layers 16 that includes a plurality of dispersed particles 214 of the particle core materials 218 . This unique structure may include metastable combinations of materials that would be very difficult or impossible to form by solidification from a melt having the same relative amounts of the constituent materials. The coating layers and associated coating materials may be selected to provide selectable and controllable dissolution in a predetermined fluid environment, such as a wellbore environment, where the predetermined fluid may be a commonly used wellbore fluid that is either injected into the wellbore or extracted from the wellbore. As will be further understood from the description herein, controlled dissolution of the nanomatrix exposes the dispersed particles of the core materials. The particle core materials may also be selected to also provide selectable and controllable dissolution in the wellbore fluid. Alternately, they may also be selected to provide a particular mechanical property, such as compressive strength or sheer strength, to the powder compact 200 , without necessarily providing selectable and controlled dissolution of the core materials themselves, since selectable and controlled dissolution of the nanomatrix material surrounding these particles will necessarily release them so that they are carried away by the wellbore fluid. The microstructural morphology of the substantially-continuous, cellular nanomatrix 216 , which may be selected to provide a strengthening phase material, with dispersed particles 214 , which may be selected to provide equiaxed dispersed particles 214 , provides these powder compacts with enhanced mechanical properties, including compressive strength and sheer strength, since the resulting morphology of the nanomatrix/dispersed particles can be manipulated to provide strengthening through the processes that are akin to traditional strengthening mechanisms, such as grain size reduction, solution hardening through the use of impurity atoms, precipitation or age hardening and strength/work hardening mechanisms. The nanomatrix/dispersed particle structure tends to limit dislocation movement by virtue of the numerous particle nanomatrix interfaces, as well as interfaces between discrete layers within the nanomatrix material as described herein. This is exemplified in the fracture behavior of these materials, as illustrated in FIGS. 23 and 24 . In FIG. 23 , a powder compact 200 made using uncoated pure Mg powder and subjected to a shear stress sufficient to induce failure demonstrated intergranular fracture. In contrast, in FIG. 24 , a powder compact 200 made using powder particles 12 having pure Mg powder particle cores 14 to form dispersed particles 214 and metallic coating layers 16 that includes Al to form nanomatrix 216 and subjected to a shear stress sufficient to induce failure demonstrated transgranular fracture and a substantially higher fracture stress as described herein. Because these materials have high-strength characteristics, the core material and coating material may be selected to utilize low density materials or other low density materials, such as low-density metals, ceramics, glasses or carbon, that otherwise would not provide the necessary strength characteristics for use in the desired applications, including wellbore tools and components.
[0061] Somewhat related to such materials are US Publication 2010/0041155; 8,021,721 and 8,006757.
[0062] The present invention relates in part to a method of using the controlled electrolytic materials (CEM) as described above to seal existing perforations to facilitate refracturing of a zone that had been previously fractured by using a bottom hole assembly (BHA) that isolates a now plugged perforation that was plugged with CEM to remove it in a predetermined time interval so that the same perforation can be refractured. Additionally new perforations can also be made such as with a jet tool before the CEM covered perforations are removed by fluid delivered to the BHA. Depending on the placement of the BHA with respect to the perforation to be refractured the refracturing can occur in the annulus surrounding the BHA or through the coiled or other tubing supporting the BHA. This versatility allows the refracturing to occur in either bottom up or top down directions or, stated differently for horizontal boreholes, toward the surface or away from the surface. These and other aspects of the present invention will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be found in the appended claims.
SUMMARY OF THE INVENTION
[0063] The method of the present invention deploys CEM into the existing perforations to seal them and then using a BHA that isolates a portion of the wellbore to deliver a material that removes the CEM at a predetermined rate so that the BHA can be used to refracture the recently opened perforation. Additional new perforations can be made and fractured during the process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] FIG. 1 is prior art a photomicrograph of a powder 10 as disclosed herein that has been embedded in an epoxy specimen mounting material and sectioned;
[0065] FIG. 2 is a prior art schematic illustration of an exemplary embodiment of a powder particle 12 as it would appear in an exemplary section view represented by section 2 - 2 of FIG. 1 ;
[0066] FIG. 3 is a prior art schematic illustration of a second exemplary embodiment of a powder particle 12 as it would appear in a second exemplary section view represented by section 2 - 2 of FIG. 1 ;
[0067] FIG. 4 is a prior art schematic illustration of a third exemplary embodiment of a powder particle 12 as it would appear in a third exemplary section view represented by section 2 - 2 of FIG. 1 ;
[0068] FIG. 5 is a prior art schematic illustration of a fourth exemplary embodiment of a powder particle 12 as it would appear in a fourth exemplary section view represented by section 2 - 2 of FIG. 1 ;
[0069] FIG. 6 is a prior art schematic illustration of a second exemplary embodiment of a powder as disclosed herein having a multi-modal distribution of particle sizes;
[0070] FIG. 7 is a prior art schematic illustration of a third exemplary embodiment of a powder as disclosed herein having a multi-modal distribution of particle sizes;
[0071] FIG. 8 is a prior art flow chart of an exemplary embodiment of a method of making a powder as disclosed herein;
[0072] FIG. 9 is a prior art photomicrograph of an exemplary embodiment of a powder compact as disclosed herein;
[0073] FIG. 10 is a prior art schematic of illustration of an exemplary embodiment of the powder compact of FIG. 9 made using a powder having single-layer coated powder particles as it would appear taken along section 10 - 10 ;
[0074] FIG. 11 is a prior art schematic illustration of an exemplary embodiment of a powder compact as disclosed herein having a homogenous multi-modal distribution of particle sizes;
[0075] FIG. 12 is a prior art schematic illustration of an exemplary embodiment of a powder compact as disclosed herein having a non-homogeneous, multi-modal distribution of particle sizes;
[0076] FIG. 13 is a prior art schematic illustration of an exemplary embodiment of a powder compact as disclosed herein formed from a first powder and a second powder and having a homogenous multi-modal distribution of particle sizes;
[0077] FIG. 14 is a prior art schematic illustration of an exemplary embodiment of a powder compact as disclosed herein formed from a first powder and a second powder and having a non-homogeneous multi-modal distribution of particle sizes.
[0078] FIG. 15 is a prior art schematic of illustration of another exemplary embodiment of the powder compact of FIG. 9 made using a powder having multilayer coated powder particles as it would appear taken along section 10 - 10 ;
[0079] FIG. 16 is a prior art schematic cross-sectional illustration of an exemplary embodiment of a precursor powder compact;
[0080] FIG. 17 is a prior art flow chart of an exemplary embodiment of a method of making a powder compact as disclosed herein;
[0081] FIG. 18 is a prior art table that describes the particle core and metallic coating layer configurations for powder particles and powders used to make exemplary embodiments of powder compacts for testing as disclosed herein;
[0082] FIG. 19 a prior art plot of the compressive strength of the powder compacts of FIG. 18 both dry and in an aqueous solution comprising 3% KCl;
[0083] FIG. 20 is a prior art plot of the rate of corrosion (ROC) of the powder compacts of FIG. 18 in an aqueous solution comprising 3% KCl at 200° F. and room temperature;
[0084] FIG. 21 is a prior art plot of the ROC of the powder compacts of FIG. 18 in 15% HCl;
[0085] FIG. 22 is a prior art schematic illustration of a change in a property of a powder compact as disclosed herein as a function of time and a change in condition of the powder compact environment;
[0086] FIG. 23 is a prior art electron photomicrograph of a fracture surface of a powder compact formed from a pure Mg powder;
[0087] FIG. 24 is a prior art electron photomicrograph of a fracture surface of an exemplary embodiment of a powder metal compact as described herein;
[0088] FIG. 25 is a prior art plot of compressive strength of a powder compact as a function the amount of a constituent (Al 2 O 3 ) of the cellular nanomatrix;
[0089] FIG. 26 shows a plug and perforate well that is in need of refracturing;
[0090] FIG. 27 is the view of FIG. 26 with the CEM balls in position to block the existing perforations;
[0091] FIG. 28 is the view of FIG. 27 showing the BHA that is used to selectively open blocked perforations with a corrosive material so that refracturing can take place.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0092] FIG. 26 shows a horizontal zone 500 that has been perforated before leaving perforations 501 - 507 near a heel 508 . A production string 510 extends from a wellhead 512 at the surface 514 which can be subsea. The well in FIG. 26 is in need of re-stimulation. In order to accomplish this, the existing perforations 501 - 507 need to first be sealed and then selectively opened so that refracturing can take place through them or alternatively new perforations can be created in the zone 500 .
[0093] FIG. 27 shows the controlled electrolytic materials (CEM) as described above preferably in the form of spheres 516 being pumped to the perforations 501 - 507 until such time as those perforations are plugged up as detected by a surface pressure buildup at the surface 514 .
[0094] After that is accomplished a surface acid tank 516 in conjunction with pump 518 is used to deliver the corrosive material through a coiled tubing unit 520 that features a gooseneck 522 through a lubricator 524 . The coiled tubing 525 supports a bottom hole assembly 526 that has one of several configurations. As shown in FIG. 28 in one embodiment there is a resettable packer 528 with either a lower end outlet 530 or a side outlet through a circulation sub above the packer 528 as shown schematically by arrow 530 . The CEM is delivered to all perforations 501 - 507 with the packer 528 unset.
[0095] If using the bottom outlet 530 the packer is set above a target perforation that happens to be plugged with the CEM balls 516 and the corrosive material from tank 516 is delivered to the zone such as 507 which is the lowermost zone. To do this the packer 528 is set between zones 506 and 507 and the corrosive material opens the perforation 507 in a predetermined time whereupon the frac fluid can be pumped through the coiled tubing 525 to the exit 530 to now refracture the perforations 507 through the coiled tubing 525 .
[0096] In the event the circulating sub 530 is used then the packer is initially located below perforations 507 and acid from tank 516 in a measured amount is spotted at perforations 507 but is stopped short of perforations 506 due to precise measuring of the amount of acid needed to cover the perforations 507 . After waiting the predetermined time for the CEM balls to be removed, the frac fluid is delivered through the annulus 532 while the coiled tubing 525 is closed off at the surface 514 such as by operating valves on the coiled tubing unit 520 . The packer 528 is released and relocated to just below perforations 506 and the process is repeated for a bottom up order for the refracturing.
[0097] If the lower end outlet 530 is used the procedure is the same as above except the start location is below perforations 506 to start refracturing perforations 507 followed by sequential release and resetting of the packer 528 to below perforations 505 to treat perforations 506 and so on for a bottom up refracturing toward the surface 514 . Doing the refracturing through the annulus 532 using the circulation sub 530 is preferred as lower pressure drop is experienced in the annulus than pumping through the coiled tubing 525 .
[0098] Alternatively, a spaced pair of packers 528 can be used with a circulation sub in between them. When doing this the amount of acid from the tank 516 does not need to be as accurately measured because the possibility of reaching the next adjacent perforation with the acid is eliminated with the pair of packers 528 rather than leaving the other perforations open to acid flow when using a single packer and trying to spot the acid adjacent a single target formation. With the spaced packer the refracturing can occur in any order.
[0099] Those skilled in the art will appreciate that using CEM allows occluding the existing perforations in a plug and perforate well so that the perforations can be sequentially opened in a known amount of time with a corrosive material spotted adjacent the isolated perforation or the perforation adjacent the packer. Refracturing follows after a known amount of time has passed with acid exposure to the CEM to sufficiently open the perforation for refracturing. In the preferred way the single resettable packer is used in conjunction with the circulation sub so that the packer is set below a perforation of interest and acid is delivered through the string in a predetermined amount so that the acidic material just reaches the perforation in interest. After a predetermined amount of time the fracturing takes places through the surrounding annulus with the coiled tubing closed off so as to reduce friction losses and the potential for sand buildup in the wellbore such as when using the alternate configuration of refracturing through the coiled tubing itself. The use of the CEM material allows precise control of the amount of time it will take to sufficiently undermine the CEM plug at the perforation in question so that the refracturing can proceed. Some parts of the CEM plug can be pushed into the perforation with the refracturing without adversely affecting the access for the refracturing.
[0100] The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
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The method of the present invention deploys CEM into the existing perforations to seal them and then using a BHA that isolates a portion of the wellbore to deliver a material that removes the CEM at a predetermined rate so that the BHA can be used to refracture the recently opened perforation. Additional new perforations can be made and fractured during the process.
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BACKGROUND OF THE INVENTION
This invention relates generally to a self-generating gas pressure apparatus such as an expandable pouch means positionable in a container containing a fluid so as to provide pressure on the fluid so that it can be dispensed from the container, and in particular to a method for gas generation employing gas-producing chemical reactants provided with a nucleating agent to enhance the speed and maintenance of gas production and resultant pressure within the apparatus.
The use of self-generating gas pressure apparatus in general within a container from which a fluid is to be dispensed under pressure is well-known in the art. U.S. Pat. Nos. 4,360,131, 4,376,500, 4,478,044 and 4,513,884, for example, describe various gas-generating pressure apparatus. Typically, an expandable closed vessel such as a pouch means having a plurality of internal compartments is employed, with the compartments having interfacing barriers or individualized walls formed by seals which are rupturable under pressure. Within adjacent compartments, for example, one such compartment will contain a first chemical compound and the second compartment will contain a second chemical compound. The particular compounds are chosen from among those which react with each other to form a gas. Thus, for example, one compartment may contain citric acid, while the other compartment contains sodium bicarbonate. When these two compounds mix with each other, they react to produce carbon dioxide. To accomplish such mixing in the expandable vessel, a trigger reaction is permitted to occur which subsequently causes the rupture of the seal which interfaces between the two adjacent compartments. This results in the mixture and reaction of the two compounds to produce a gas which expands the vessel to thereby apply pressure on the fluid within the container in which the expandable vessel is housed. A novel self-generating pressure applying means is taught in co-pending and commonly-assigned U.S. patent application Ser. No. 34,900, filed Apr. 6, 1987, incorporated herein by reference.
While gas pressure generation occurs as above described and is generally adequate as long as sufficient time passes between individual dispensing procedures to thereby achieve pressure regeneration from continued chemical reaction, such generation may not be rapid enough or sufficiently uniform to provide optimum pressure to the fluid to be dispensed from the containers during continued dispensing, resulting in a slow fluid flow from the container as the dispensing procedure continues. Accordingly, it is a primary object of the present invention to provide a self-generating gas pressure apparatus wherein gas formation occurs relatively rapidly and uniformly. Another object of the present invention is to provide apparatus wherein chemical compounds which react with each other to produce gas react in the presence of a nucleating agent. Yet another object of the present invention is to provide apparatus wherein caking of the nucleating agent employed as well as production of a stable foam during reaction of the chemical compounds is retarded. These and other objects of the present invention will become apparent throughout the description thereof.
SUMMARY OF THE INVENTION
The subject of the present invention comprises a self-generating gas pressure apparatus, such as an expandable closed vessel as exemplified by a pouch means, for placement within a container from which a fluid therein is to be dispensed under pressure. The apparatus comprises a plurality of internal, sealed, respectively adjacent compartments formed by respective interfacing seal means which are rupturable under pressure and contain respective chemical compounds which when mixed upon the rupture of respective interfacing seal means produce a gas. Within at least two adjacent internal compartments are respectively housed a first chemical compound in aqueous solution and a second chemical compound in aqueous solution which, when mixed together, produce a gas. Two preferred reactants are citric acid and sodium bicarbonate which produce carbon dioxide. At least one of the solutions additionally contains an insoluble nucleating agent physically characterized as large surface-area particles preferably having a plurality of sharp edges. Diatomaceous earth exemplifies such particles. Preferably, an anti-caking agent and an anti-foam agent are also included in the solution containing the nucleating agent. Upon rupture of the seal means between the two adjacent compartments, one large compartment is formed and the first and second chemical compounds mix with each other to produce the gas which expands the apparatus and thereby applies pressure to the fluid within the container wherein the apparatus is housed so that this fluid can be dispensed under pressure. Inclusion of the nucleating agent forces supersaturated gas out of the liquid phase and into the gas phase more quickly for more rapid and maintained equilibrium conditions between the chemical compound reactants. Additionally, of course, the more rapid gas pressure production will act to rupture subsequent seals to adjacent reactant-containing compartments more quickly to thereby speed additional reactant mixing and consequent production of more gas pressure more quickly. In this manner a greater pressure is generated and maintained more quickly to aid in effective continuous pressurized dispensing procedures.
BRIEF DESCRIPTION OF THE DRAWINGS
An illustrative and presently preferred embodiment of the invention is shown in the accompanying drawings in which:
FIG. 1 is a front elevational view with portions broken away illustrating an expandable pouch means and the components of a gas generating system;
FIG. 2 is a cross-sectional view taken on the line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view of a partially expanded expandable pouch means;
FIG. 4 is a cross-sectional view of a container for holding one component of a gas generating system;
FIG. 5 is a cross-sectional view, except for the dispensing means, illustrating a container means and its supporting structure in an upright position for shipping and commercial storage and a partially expanded expandable pouch means;
FIG. 6 is a view similar to FIG. 5 but with the container means in a dispensing position and after more than half of the fluid has been dispensed;
FIG. 7 is a view similar to FIG. 5 but after substantially all of the fluid has been dispensed; and
FIG. 8 is a graph which illustrates pressure generation profiles of gas-producing chemical reactants with and without a nucleating agent being present.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An expandable pouch means 2 of the presently preferred embodiment is illustrated in FIGS. 1-3 and comprises two relatively flat sheets 4 and 6 of a flexible plastic material in superposed relationship and made from a gas and liquid impermeable material such as a composite material of an outside layer of a polyester with an inside coating of PVDC, a layer of polyethylene and a layer of an ionomer resin, such as that marketed by Dupont under the trade designation SURLYN. Each of the flat sheets 4 and 6 is octagonal in shape having a length greater than its width and with peripheral edge portions 8 and 10 permanently joined together by a permanent sealing means 12 formed by heat sealing at a temperature of about 300° F. for 0.5 second. The expandable pouch 2 is formed into a first compartment 14 and a plurality of other compartments 16 by a plurality of lengthwise extending strips 18 which join together opposed portions of the flat sheets 4 and 6 using a semipermanent pressure-rupturable sealing means 20 formed by heat sealing at a temperature of about 250° F. for 0.5 second. If the flat sheets 4 and 6 are formed from different plastic materials, the temperature and time would be adjusted as required to obtain the desired type of seal. Also, if desirable, a suitable adhesive could be used to obtain the desired results.
The normal operation of an expandable pouch means 2 uses some delaying system so that the chemical reaction can be started and still allow for sufficient time for expandable pouch means 2 to be inserted into the container means and suitable sealing and dispensing means applied to the container means. The delaying system for this invention is illustrated in FIG. 1 wherein the first compartment is sub-divided to three sub-compartments 22, 24 and 26. The sub-compartment 22 is formed by a lengthwise extending strip 18, as described above, extending parallel to the next adjacent permanent lengthwise extending sealed edge portions 8 and 10. The sub-compartments 24 and 26 are formed by a lengthwise extending strip 18, as described above, extending parallel to and spaced inwardly from the strip 18 forming sub-compartment 22. The lower portion 28 of the strip 18 forming the sub-compartments 24 and 26 has a reduced width for a purpose described below. A quantity of a first chemical compound in aqueous solution, here a 50% citric acid solution 30, is contained in the sub-compartment 22. A tablet 32 comprising the second compound, here a concentrated sodium bicarbonate tablet, is contained in the sub-compartment 24. An aqueous solution 34 of sodium bicarbonate additionally containing a nucleating agent comprising diatomaceous earth, a surfactant, and an anti-foam agent is contained in the sub-compartment 26. The other compartments 16 each contain a quantity of the citric acid solution 30. It is to be understood, of course, that other or additional chemical reactants can be employed as would be recognized by the skilled artisan to produce a desired gas end-product.
In operation, a force is applied to the sub-compartment 22 by hand prior to insertion of the pouch means 2 into the container means to rupture the strip 18 so that the citric acid solution 30 flows into sub-compartment 24 to contact the sodium bicarbonate tablet 32, and begins to react therewith to generate carbon dioxide gas. This reaction with the tablet 32 proceeds at a rate to provide the above-described delaying system to allow the expandable pouch means 2 to be inserted into the container means and suitable sealing and dispensing means applied to the container means. The generation of the carbon dioxide gas forms a pressurized force forcing the strip 18 between the sub-compartment 24 and the sub-compartment 26 to rupture at the weakened reduced width 28 to combine the sub-compartments 24 and 26. This permits the citric acid solution 30 to flow into sub-compartment 26 and into contact with the sodium bicarbonate solution 34 and further react to continue the generation of carbon dioxide gas. As the generation of the carbon dioxide gas continues, the pressure within the first compartment 14 is increased so as to expand the portions of the flat sheets 4 and 6 forming the first compartment 14. The dispensing of fluid from the container means, as described below, will provide space for further expansion of the expandable pouch means 2. When the limit of the volume of the first compartment 14 is reached, further generation of carbon dioxide gas therein will result in a force being applied to the strip 18 between the first compartment 14 and the next adjacent other compartment 16 so as to rupture such strip 18. The citric acid solution 30 in the next adjacent other compartment 16 will contact the sodium bicarbonate solution 34 to continue the generation of carbon dioxide gas. This sequence will continue until the expandable pouch means 2 has been substantially completely expanded. The total amount of citric acid solution 30 in the entire pouch means 2 here exemplified is 81.1 ml. As would be recognized by the skilled artisan, reactant quantities are, of course, chosen according to the volume of the pouch means 2 as well as the magnitude of chemical reaction desired.
Another embodiment for the provision of the citric acid solution 30 in the first compartment 14 is illustrated in FIG. 4 and is particularly useful when the fluid in the container means is a carbonated beverage, such as beer. A substantially rigid container 40, which in the preferred embodiment is plastic, has a closed end 42 and an open end 44. The container 40 is illustrated as being a tube but it is to be understood that it can be of any desired geometrical configuration. A barb 46 is secured to the inner surface 48 of the container 40 with its pointed end 50 facing and relatively close to the open end 44. A quantity of the citric acid solution 30 is placed in the container 40 and the open end 44 is sealed by a flexible membrane 52. The strips 18 forming the sub-compartments 22, 24 and 26 are not used in this modification so that the first compartment 14 is one unitary compartment. The filled container 40 is contained in the first compartment 14 with the sodium bicarbonate solution 34. After the expandable pouch means 2 has been inserted into the container means filled with a carbonated beverage, as described below, the pressures generated by the carbonated beverage in the container means will exert a pressure on the flexible membrane 52 moving it into contact with the pointed end 50 to rupture the flexible membrane 52 and permit the citric acid solution 30 to flow into the sodium bicarbonate solution 34 in first compartment 14 to start the carbon dioxide gas generating system.
The location of the expandable pouch means 2 in a container means 60 is illustrated in FIGS. 5-7. In FIG. 5, the container means 60 is supported in the upright position for shipping and commercial storage by a support member 62. The expandable pouch means 2 has a length substantially greater than the longitudinal extent of the container means 60 and a width substantially greater than the diameter of the container means 60. Therefore, in order to insert the expandable pouch means 2 through an opening 64 in the container means 60, it is necessary to apply a force in a widthwise direction to compact the expandable pouch means 2 in that direction so that its cross-sectional configuration is less than the cross-sectional configuration of the opening 64. Also, as the expandable pouch means 2 is inserted into the container means 60, it is necessary to apply a force in the lengthwise direction to push the expandable pouch means 2 into the container means 60. This results in a crumpling of the expandable pouch means 2 in the lengthwise direction. Since the material in the expandable pouch means 2 has little tendency to resile, it will remain crumpled while a dispensing means 66 for dispensing portions of the material in the container means 60 is assembled in the opening 64. In the preferred embodiment, the fluid 68, such as a carbonated beverage such as beer, is in the container means 60 prior to the insertion of the expandable pouch means 2. If desired, the expandable pouch means 2 can be inserted into the container means 60 prior to the filling of it with the fluid. The fluid level 70 is slightly below the dispensing means 66. The strip 18 forming sub-compartment 22 is ruptured prior to the insertion of the expandable pouch means 2 into the container means 60 so that the gas generating system is in operation, as described above, and the first compartment 14 has been at least partially expanded in the illustration in FIG. 5. The container means 60 is illustrated in the fluid dispensable position in FIGS. 6 and 7. Another support member 72 has been previously secured to the container means 60. The support member 62 and the support member 72 have planar surfaces 74 and 76 for supporting the container means 60 on a generally horizontal surface, such as a shelf of a home refrigerator. The planar surfaces 74 and 76 also function to maintain the container means 60 in such fluid dispensable position. While it is highly preferred to use the horizontal dispensing position, it is understood that the pressure in the container means provided by the expandable pouch means would permit dispensing in other positions, some of which may require different types of dispensing means. In FIG. 6, more than half of the fluid has been dispensed from the container means 60. The first compartment 14 and several of the next adjacent other compartments 16 have been expanded, as described above, to form a combined compartment which is located adjacent to the upper longitudinally extending portion of the container means 60. In FIG. 7, the expandable pouch means 2 is substantially fully expanded and is substantially completely in contact with the inner surface of the container means 60 except for the portion defining the opening 64. After substantially all the fluid 68 has been dispensed from the container means 60, a pressure relieving device (not shown) in the dispensing means 66 is actuated and the carbon dioxide gas in the expanded pouch means 2 is removed through the dispensing means 66 so that the container means 60 and the expandable pouch means 2 are substantially at atmospheric pressure and the container means 60 can be safely placed in the trash.
When the expandable pouch means 2 is being inserted into the container means 60, the strips 18 are generally parallel with the longitudinal axis of container means 60 to thereby achieve optimum positioning for fluid dispensing under pressure. As explained above, the relative length of the expandable pouch means 2 causes it to be crumpled as it is inserted into the container means 60. However, the strips 18 still extend generally in the same direction as the longitudinal axis of the container means 60. As fluid is dispensed from the container means 60 and more of the other compartments 16 are expanded, the expanded portion of the expandable pouch means 2 gradually moves into a position wherein its longitudinal axis is parallel to the longitudinal axis of the container means 60, as illustrated in FIG. 6. When the expandable pouch means 2 is fully expanded, as illustrated in FIG. 7, the longitudinal axes of the expandable pouch means 2 and the container means 60 will substantially coincide.
As illustrated in FIGS. 5-7, the container means 60 comprises a blown hollow integral plastic container means made of one piece of integrally molded plastic material, such as polyethylene terephthalate (PET), and having a hemispherical top portion 78, an annular cylindrical central portion 80, a hemispherical bottom portion 82 and a neck portion 84 defining the opening 64. The container means 60 is large enough to hold 288 fluid ounces of a beverage.
The expandable pouch means 2 may be of any size and shape so as to be commensurate with the size and shape of the container means 60 with which it is to be used. Also, the expandable pouch means 2 may be used to dispense any kind of material from the container means as is customary in this art. However, in the preferred embodiment of the invention, the expandable pouch means 2 is designed for applying pressure to a quantity of beer equal to 288 fluid ounces or 2.25 gallons in a container means 60. The expandable pouch means 2 exemplified is designed for such a container means wherein the container means 60 has an overall length along its longitudinal axis of about 15.5 inches, an external diameter of the cylindrical central portion 70 of about 9.0 inches, and an average wall thickness of about 0.030 inches. The expandable pouch means 2 has an overall length of about 17 inches and an overall width of about 15.5 inches and has nine compartments formed therein.
The first compartment 14 will expand to cause the rupturable seam strip 18 between it and the next adjacent other compartment to rupture. The first compartment 14 or sub-compartment 26 contains 100 grams of sodium bicarbonate, which is more than the stochiometric amount necessary to react with the citric acid to produce the required pressurizing gas, combined with 150 ml water, 10 g diatomaceous earth (Aqua Cell, manufactured by Manville Corporation), 5 ml surfactant (Dowfax 2Al , manufactured by Dow Chemical Co.), and 1 ml anti-foam agent (Dow-Corning Antifoam FG 10, manufactured by Dow-Corning Co.). While diatomaceous earth is a preferred nucleating agent, it is to be understood that other or additional nucleating agents can be employed so long as they meet the above-recited physical characteristics of large surface area and sharp edges. A surfactant is preferably included to inhibit caking of the nucleating agent, and can be chosen from any appropriate synthetic detergent or dispersing agent as would be recognized by the skilled artisan. An anti-foam agent is preferably included to inhibit filling of the pouch means 2 with stable foam produced by the surfactant, and likewise can be chosen from appropriate and recognized anti-foam agents. It is preferred that the chemical compound reactants, nucleating agent, surfactant, and anti-foam agent all be acceptable for food contact or food grade if the fluid to be disposed from the container in which the pouch means 2 is placed is to be drunk. This precaution is taken in the event the pouch means 2 accidently ruptures and the contents therein become mixed with the fluid to be dispensed and consumed.
FIG. 8 graphically displays the average pressures present within the container 60 from several comparison tests between the presence and absence of diatomaceous earth, surfactant and anti-foam agent in the sodium bicarbonate solution 34 of the pouch means 2 within the container 60 while beer is being essentially continuously dispensed from the container at the rate of about 250 ml per minute. All other conditions were held constant. As is evident from these results, the presence of the nucleating agent performed to maintain a higher pressure beginning at about two minutes into the dispensing procedure and contained for the duration of the time span exemplified.
While an illustrative and presently preferred embodiment of the invention has been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
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A self-generating gas pressure apparatus such as an expandable closed pouch for placement within a container from which a fluid therein is to be dispensed under pressure. The apparatus has a plurality of internal compartments formed by pressure-rupturable seals and containing respective chemical compounds which when mixed upon adjacent-compartment seal rupture produce a gas. At least one of two adjacently-housed chemical compounds has in addition thereto a nucleating agent such as diatomaceous earth which acts to more rapidly force gas generated in the reaction of the adjacently-housed chemical compounds out of solution and thereby provide an operative pressure to the apparatus more quickly.
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RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Utility Application 61/393,740 filed on Oct. 15, 2010, the entirety of which is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to the field of enzymatic conversion of biomass to monomeric sugars and particularly to mixing the biomass with enzymes to promote hydrolysis.
[0003] Biomass feedstock may be solely lignocellulosic material or a mixture of lignocellulosic and other materials. Polysaccharide biomass is typically a mixture of starch and lignocellulosic materials. The starch may be contained in grains or a refined starch added as feedstock to form the biomass. The biomass feedstock may also include polymers and other materials.
[0004] Enzymes, such as cellulose, are mixed with the biomass to promote hydrolysis. Mixing ensures that the enzymes continually and repeatedly move into contact with chemical reaction sites in the biomass. In addition or in place of enzymes other cellulose degrading organisms and biocatalysts, such as thermophilic bacterium or yeast, may be added to the biomass to promote hydrolysis or other degradation of the biomass.
[0005] The different feedstock materials and enzymes (or other degrading materials) are mixed together to form the biomass mixture. The biomass mixture may have characteristics similar to a high matter content powder. Liquid may also be added to the biomass mixture to form a high liquid slurry. Liquid is added to liquefy biomass solids and generate a uniform biomass emulsion formed of feedstock and liquids which have significant differences in their characteristics.
[0006] Mixers, constant stir reactors and other such mixing or agitation devices may be used to mix and liquefy the feedstock and enzymes to form the biomass mixture. These devices conventionally are cylindrical vessels arranged vertically and having mechanical mixing devices, such as stirrers having radial arms and blades. These mixing devices generally rotate about a vertical shaft and move through the biomass. The period of mixing needed for the biomass mixture depends on the feedstocks used to form the biomass.
[0007] Enzymatic liquefaction of lignocellulosic biomass may require several hours of mixing. This mixing process reduces the viscosity of the biomass as the biomass converts from a generally solids composition to a liquefied slurry. Biomass pretreated for enzymatic conversion to monomeric sugars typically starts the mixing process having a fibrous or mud-like consistency. The enzymes added to the biomass typically have a relatively low concentration with respect to the biomass. The biomass and enzyme mixture tends to be highly viscous as it enters a mixing and pretreatment reactor system, which include one or more hydrolysis reactor vessels.
[0008] Due to the high viscosity of the biomass entering the hydrolysis reactor vessel, a large force (torque) is needed to turn the mixing devices and properly mix the enzymes with the biomass. The mixing speed of the mixing arms and other mixer components in the mixing chamber is typically below 300 revolutions per minute (rpm). The required mixing force traditionally limits the size of the mixing vessels. The conventional mixing devices tend to be small diameter vessels because the torque needed to rotate the mixing arms increases exponentially with the radial length of the arms. Due to the high viscosity of the biomass, the radial length of the arms is traditionally been short so that the can be moved arms through the biomass. Similarly, the motors that turn the mixing arms have maximum power limitations that constrain the maximum length of the mixing arms. Due to the constraints of the motor and the mechanical strength of the mixing components, the vessels for mixing the highly viscous pre-treated biomass have conventionally been small and narrow.
[0009] Further, the mixing vessels for enzymatic liquefaction of lignocellulosic biomass have traditionally been operated in a batch mode rather than a continuous mode. Batch mode is often better suited to situations were several smaller mixing vessels feed a larger downstream vessel, such as a digester or other reactor vessel.
[0010] Recirculation of liquefied material to dilute the incoming pretreated biomass has been proposed to decrease the viscosity, and improve the mixing. Recirculation has a disadvantage in that additional mixing volume is required to achieve the desired retention time in the vessel. Batch processing adds volume to the system, as time has to be provided to fill and empty the vessel.
[0011] There is a need for large mixing vessels capable of mixing highly viscous biomass with enzymes. These vessels would preferably be continuous flow vessels in which biomass flows continuously in, through and out of the vessel. A large vessel would provide efficient, high flow capacity for mixing biomass and enzymes.
BRIEF DESCRIPTION OF THE INVENTION
[0012] A novel apparatus and method is disclosed herein for mixing, e.g., liquefaction, of biomass. The apparatus and method may be used for the liquefaction and saccharification of polysaccharide containing biomasses, which may have a dryer matter content of above 10% w/w (weight/weight). The apparatus and method combines enzymatic hydrolysis with a mixing process that relies on physical forces, such as gravity and centrifugal force, to ensure that the biomasses are subjected to mechanical forces, such as shear and tear forces.
[0013] The apparatus and method disclosed herein may be applied in processes of biomasses, such as for fermentation of biomass to bio-alcohols such as ethanol or butanol, forming bio-gas, forming specialty carbohydrates for food and feed, forming carbo-hydrate feedstock and for processing biomass into plastics and chemicals.
[0014] A mixing and reactor vessel is disclosed herein comprising: an internal mixing chamber including a first chamber section having a cross-sectional area expanding from a biomass inlet to the internal mixing chamber to the a second chamber section, the second chamber section having a substantially uniform internal cross-sectional area from the opposite end of the first chamber section to a discharge end of the mixing chamber; the biomass inlet is coupled to a source of pre-treated biomass external to the reactor vessel, and a rotating mixing device in the internal mixing chamber and coaxial with an axis of the reactor vessel.
[0015] A method is disclosed herein to mix biomass and an enzyme in a reactor and mixing vessel comprising the steps of: feeding the biomass and enzyme to an to the vessel, wherein the inlet is aligned with a narrow end of a first internal mixing chamber of the vessel; moving and mixing the biomass and enzyme as they flow from the narrow end to a wide end of the first internal mixing chamber section wherein the first internal mixing chamber expands in cross-section along a movement direction of the biomass and enzyme through the chamber; moving and further mixing the mixture of biomass and enzyme from the first internal mixing chamber to a second internal mixing chamber having a substantially uniform cross-sectional area in the movement direction; discharging from the vessel the biomass and enzyme mixture from a discharge outlet of the second internal mixing section. This mixture of biomass and enzyme may be an enzyme such as cellulose, a thermophilic bacterium or other cellulose degrading organism or biocatalyst.
[0016] The first internal mixing chamber may have multiple zones at different elevations in the vessel. These zones may be separated via optional and possibly adjustable bottoms, e.g., baffles or trays, in the vessel to optimize a step-wise transformation of the biomass solids to a slurry. These intermediate bottoms are preferably horizontal and extend substantially the entire cross-section of the vessel at the elevation where the platform is positioned. The bottoms may also be slightly inclined with respect to horizontal. Adjustable openings in the intermediate bottoms may be provided to vary the flow through the bottoms and from one zone to the next one. Depending on the dry matter feedstock and mixing slurry in question (which could be an enzyme mixture), that may be no intermediate bottoms in the vessel such that the downward movement of the biomass mixture is dependent solely on gravity and plugflow downflow of the induced matter through the reactor vessel.
[0017] The already conditioned (liquefied) slurry flows from lower zones (or the bottom) of the mixing vessel. A portion of the slurry flow may be pumped or circulated to upper zones in the vessel to adjust the slowly changing viscosity of the biomass feedstock at the upper elevations of the vessel.
[0018] The conical top may provide approximately constant torque as the material flows through the mixer. The angle of the cone could change as the diameter increases, as the viscosity decrease is fast in the beginning and then slows down. The vessel top may also consist of several stacked concentric cylinders with increasing diameters from top to bottom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematic diagram showing in cross-section a vertically aligned mixing and hydrolysis reaction vessel for biomass.
[0020] FIG. 2 is a chart showing an expected viscosity of the biomass in the reaction vessel shown in FIG. 1 as a function of retention time of the biomass in the vessel.
[0021] FIG. 3 is a schematic diagram showing in cross-section a conical mixing and hydrolysis vessel connected to a cylindrical mixing and hydrolysis reaction vessel.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 shows schematically a reactor and mixing vessel 10 having a conical upper section 12 and a cylindrical lower section 14 . These sections 12 , 14 define an internal reaction chamber in which the biomass is mixed with the enzyme(s) and is hydrolyzed. The internal reaction chamber may have a volume in a range of 50 cubic meters to 2,500 cubic meters. Narrower ranges of 200 cubic meters to 1,200 cubic meters or 400 cubic meters to 800 cubic meters will also be suitable depending on the specific application of the reaction and mixing process. The reaction chamber may be substantially larger in volume than batch mixing/reactor vessels conventionally used to mix highly viscous biomass.
[0023] The vessel includes a rotatable shaft 16 extending along the vertical axis of the vessel. The shaft is driven (rotated) by a motor and gear box drive assembly 18 , which may be mount to the top or bottom of the vessel. The shaft 16 may be to a vertical axis of the vessel and extend the height of the vessel. The shaft turns a mixing device 28 , e.g., mixing arms and paddles, that moves through and churn the biomass in the vessel.
[0024] A source 20 of biomass and enzymes may be continuously fed to an upper inlet 22 of the vessel 10 . The biomass and enzymes may be fed as a mixture to the vessel or fed separately to the vessel. The source 20 may include a short retention time horizontal mixer, in which the biomass and enzymes are brought into initial contact with each other. If desired, recycled low viscosity hydrolyzed material 21 is introduced into the source 20 or the upper inlet 22 of the vessel.
[0025] The inlet 22 feeds the biomass to a narrow region of the conical upper section 12 . The cross-sectional area of the upper section 12 expands from the upper narrow region to the transition 24 between the upper section 12 and the lower section 14 . The cross-section area of the lower section 14 may be uniform along its entire height. The bottom of the lower section is adjacent a discharge outlet 26 for the hydrolyzed biomass continuously flowing out of the vessel 10 to other process units, such as a digester, fermenter or continuing enzymatic hydrolysis vessels. The bottom of the lower section may be sloped to provide a uniform discharge from the entire cross-sectional area of the bottom of the lower section.
[0026] A mixing device 28 (shown schematically by a tree of rotating arms 30 in FIG. 1 ) is mounted to the shaft 16 and rotates through the biomass and enzymes moving downward through the upper and lower sections 12 , 14 of the vessel. The mixing device 28 may include radially extending arms or spokes 30 at various elevations in the vessel. The arms may extend horizontally or may be oblique with respect to horizontal. The arms 30 may be arranged as spokes extending from the shaft. The arms may have mixing paddles, blades or fingers 32 arranged at the radial end of the arms and optionally at various positions along the radial length of each of the arms.
[0027] The arms 30 may be adjusted to be positioned at various elevations and positions in the vessel. Similarly, the paddles, blades or fingers 32 may be adjustably mounted on each of the arms. The adjustment may change, for example, the angle at which the paddles, blades or fingers are oriented with respect to the direction of rotation of the arms. The orientation of the paddles, blades or fingers may be set to provide a slight radially outward flow to the biomass to distribute the biomass evenly through the cross-sectional area of the vessel. The rotation of arms with the paddles, blades or fingers at one or more elevations or radii may be provide may also apply a slight uplift of the biomass to prevent short-circuiting of the biomass flowing down from above through the vessel.
[0028] The arms turn in a circular rotational pattern through the biomass in the vessel. The arms are turned by the rotating shaft 16 . The movement of the arms and mixing paddles, blades or fingers mix the enzyme into the biomass and thereby cause the enzyme to come into contact with reaction sites in the biomass. The reactions between the enzyme and the biomass promotes hydrolysis of the biomass in the vessel.
[0029] Mixing baffles 32 may be installed on the inside vessel wall of the lower section 14 and optionally the upper section 12 . The biomass flowing through the lower section will have a relatively low viscosity, as compared to the viscosity at the vessel inlet. Mixing baffles are most suitable for low viscosity flows through a mixing vessel. Trays or baffles could also be installed between the mixing arms to aid in distribution of the biomass material.
[0030] The shaft and mixing arms may provide indirect cooling or heating to the biomass, such as by cooling or heating passages in the arms. Similarly, the interior walls of the vessel may be jacketed or provided with cooling or heating coils 34 .
[0031] As an example, to hydrolyze 1200 tons of biomass per day, where the biomass has a 25% solids loading, the reactor vessel should be sized to process about 5000 cubic meters of biomass during a twenty-four (24) hour retention period in the vessel. The vessel should be larger if the biomass retention period is longer, such as 72 to 120 hours. A vessel having an internal chamber volume of 15,000 cubic meters to 25,000 cubic meters may be needed to provide long retention periods of a continuous flow of a large amount of biomass, e.g., 1200 tons/day, being hydrolyzed.
[0032] The diameter, height and other dimensions of the vessel depend on the flow of biomass and retention period of the biomass in the vessel. By way of example, a reactor vessel 10 may need an effective internal volume of about 1200 cubic meters to handle 1200 tons of biomass per day at a 25 percent solids loading and a six hour retention period. Assuming that the aspect ratio (diameter to height) of the vessel is six, the diameter of the vessel would be about 5.4 meter and its height would be greater than 33 meters.
[0033] The conical upper section 12 is narrowest at the upper inlet that receives the highly viscous biomass entering the vessel. The viscosity of the biomass is greatest at the top inlet to the vessel. While the high viscosity increases the starting torque needed to turn the mixing device, the torque is lessened because of the short mixing arms at the narrow top. The biomass becomes less viscous as it mixes it the enzyme and moves down through the vessel. The lessening viscosity allows for the mixing arms to be longer without increasing the torque needed to turn shaft. The arms in the lower portions of the upper conical section are longer than most or all the upper arms 30 . Longer arms require more torque to be turned through the biomass, assuming the viscosity of the biomass remains constant. The combined effects of the reduction in viscosity of the biomass and the longer arms results in acceptable torque requirements for the mixing device in the upper conical section.
[0034] The conical geometry of the upper section reduces the starting torque requirement. Less power is required for mixing, the biomass can be more thoroughly mixed, and the biomass is less susceptible to channeling down through the vessel. The conical shape also results relatively frequent and robust mixing near the inlet of the vessel, where mixing may be most beneficial to promote hydrolysis.
[0035] Torque increases with the diameter squared. The torque required to move (mix) a fluid in a circle is a function of the force required to move the fluid times the radius of that force from the center of rotation. The force required to move the fluid is a function of the viscosity of the fluid, the velocity of the motion and the distance that the fluid has to move.
[0036] Assuming a constant fluid viscosity and constant rotation of the mixing device, the torque required to turn the mixing device depends on the square of the radius of the vessel. Due to the squared relationship between torque and vessel diameter, reducing the vessel diameter dramatically reduces the amount of torque or allows the same amount of torque to mixing a highly viscous biomass flow.
[0037] The conical upper section 12 is suited for short mixing arms in the upper region of the vessel where viscosity is high. The shortest mixing arms are at the top of the vessel where the biomass viscosity is greatest and the resistance of the biomass to mechanical mixing is high. As the biomass moves down through the upper section, the viscosity of the biomass lessens, the resistance to mixing decreases and longer mixing arms may be used in view of the increasing diameter of the conical portion of the vessel.
[0038] By knowing the viscosity of the biomass at various elevations in the upper section 12 , the angle of the cone of the upper section may be selected such that the radius of the mixing arms increases at a rate that results in uniform torque on the arms at each elevation. Thus, each mixer arm may require the same torque to mix the material, even through the diameter of the conical section is increasing in a downward direction.
[0039] Intermediate bottoms, trays or baffles 38 may be installed and adjusted to separate the upper section 12 into multiple zones to optimize a step-wise transformation of the biomass mixture to a slurry with a higher liquid content than the original biomass. The zones may be generally vertically aligned in the vessel. These intermediate and adjustable bottoms may be horizontal in the vessel and may also be slightly inclined with respect to horizontal. Further, adjustable openings in the intermediate bottoms may be used to vary the flow between the zones defined by the bottoms. Similarly, intermediate bottoms, trays and baffles 39 may be arranged in the lower section 14 into multiple zones.
[0040] FIG. 2 includes a chart 40 of viscosity of the biomass in the vessel 10 as a function of time. The chart is for illustrative purposes. The chart shows the viscosity of a biomass which is steam exploded corn stover mixed at a temperature of 50 degrees Celsius and in a vessel having mixing devices rotating at 20 rpm. The chart shows a range of viscosity values in milliPascal-second (mPas) for the biomass undergoing saccharification. The range results from two different starting mixing patterns used for the biomass.
[0041] As shown in the chart 40 , the viscosity of the biomass may reduce quickly such that the viscosity has been reduced by one-half or more after six hours of reaction time in the vessel. It is known that only about six (6) hours of reaction time (or somewhat more reaction time) is needed in the vessel to convert the viscous biomass flow to a flowing, syrupy consistency. During this initial reaction period (e.g., 15 minutes to 8 hours, preferably 1 hour to 6 hours, most preferably 2 hours to 4 hours), the apparent viscosity of the biomass decreases quickly as enzymes break down the polymeric sugars of the biomass to smaller molecule chains.
[0042] The downward flow rate of the biomass through the vessel can be calculated or estimated by conventional means. As illustrated in FIG. 2 , the reaction time of biomass in a continuous flow vessel 10 correlates with the movement of the biomass down through the vessel. The vessel may have the mixing device, heating coils and intermediate bottoms as shown in FIG. 1 . The continuous biomass flow through the vessel is represented by diagonal dashes shown in the illustration of the vessel.
[0043] Using the rate of flow through the vessel and the reaction time to reduce the biomass viscosity to a certain level, such as a 50% or less viscosity reduction, the vertical distance down through the vessel can be calculated to determine at which elevation/reaction time 42 the biomass will have a viscosity of one-half the viscosity of the biomass entering the vessel. The conical upper section 12 may be designed such that the transition 24 to the lower cylindrical section 14 occurs at the same elevation where the viscosity of the biomass is reduced by half.
[0044] FIG. 3 is a schematic diagram showing in cross-section a conical mixing and hydrolysis vessel 50 connected to a cylindrical mixing and hydrolysis reaction vessel 52 . The biomass flowing through these vessels is indicated by diagonal dashes. The conical mixing and hydrolysis vessel 50 is similar in many respects to the conical portion of the vessel 10 shown in FIG. 1 , as is indicated by the common reference numerals in FIGS. 1 and 3 .
[0045] Biomass and enzymes are fed from a source 20 to the upper inlet 22 of the narrow end of the conical mixer and reaction chamber 50 . A mixing device 28 has arms 36 that increase in length as the conical mixer increases in diameter. Intermediate bottoms, e.g., baffles, trays or other plates 38 , may be arranged in the conical vessel to regulate the downward flow of biomass through the vessel. The viscosity of the biomass falls as the biomass is mixed and reacts in the vessel 50 . The viscosity may be reduced by half as the biomass is discharged from the vessel at port 54 , as compared to the viscosity of the biomass 20 entering the vessel. A tapered or sloped bottom 56 may direct the biomass into the port 54 .
[0046] A transport conduit, e.g., pipe, 58 and a pump 60 may be used to transport the liquefied biomass to an upper inlet port 62 of the cylindrical vessel 52 . The cylindrical vessel includes a mixing device 64 and optionally baffles 32 . The mixing device is connected to a shaft 66 driven by a drive and gear assembly 68 . The hydrolyzed biomass is discharged at port 70 from the cylindrical vessel.
[0047] The invention has now been described in detail for purposes of clarity and understanding. However, it will be appreciated that certain changes and modifications to the disclosed embodiment of the invention may be practiced within the scope of the appended claims.
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A reactor apparatus including: an internal mixing chamber including a first chamber section having a cross-sectional area expanding from a biomass inlet to the internal mixing chamber to the a second chamber section; the second chamber section having a substantially uniform internal cross-sectional area from the opposite end of the first chamber section to a discharge end of the mixing chamber; the biomass inlet is coupled to a source of pre-treated biomass external to the reactor vessel, and a rotating mixing device in the internal mixing chamber and coaxial with an axis of the first chamber section.
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BACKGROUND OF THE INVENTION
There are many industrial operations which require that a supply of liquid be spread into a continuously flowing thin sheet and deposited on a surface. Among such operations is the step of forming a sheet of pulp that eventually becomes a finished pulp or paper product. In this operation, a large drum rotates partially submerged in a pool of pulp dispersed in water. As the drum rotates, a suction is applied from inside the drum causing pulp to be deposited on the drum. The wet pulp sheet on the drum must be washed several times to remove any impurities and recover the chemicals. In so doing, it is necessary to apply to the sheet of pulp sufficient wash water to displace the chemical laden liquid within the pulp sheet. It is not feasible to apply wash water in the form of a spray because it would cause loss of washing efficiency due to air impingement causing a displacement reduction. Because of economic and environmental requirements, it is desirable to operate with a minimum displacement ratio. Accordingly, it has been found necessary to distribute the wash water in the form of a thin film that can be applied gently to the surface of the moving sheet of wet pulp. Normally, there is a spillway surface which would direct a film of water tangentially onto the moving pulp sheet and the only problem is to be able to distribute the wash water evenly over the spillway so as to produce a consistent and gently flowing sheet of wash water to the wet pulp sheet. Spoon deflectors, whistle showers, and wires have been employed in the past to change individual streams of water into spray patterns that will distribute themselves automatically over the surface of a spillway. These have been unsatisfactory for several reasons including inconsistencies in the thickness of the film of water as well as inconsistencies in the uniformity of flow across the face of the washing apparatus. Furthermore, these previously used devices caused an undesirable amount of heat loss in the wash water.
Accordingly, it is an object of this invention to provide an improved liquid distribution device which can continuously supply a sheet of wash water in a constant thickness to a spillway which directs the film of water onto a moving pulp sheet. It is another object of this invention to provide an improved distribution device that minimizes the heat loss involved in the distribution. Still another object of this invention is to provide an improved liquid distribution device which is not subject to plugging and, therefore, is less likely to produce varying thicknesses in the sheet of liquid being distributed. Still, other objects will be apparent from the more detailed description of this invention which follows.
BRIEF DESCRIPTION OF THE INVENTION
This invention involves a liquid distribution device comprising an elongated horizontal pipe member having a plurality of spaced passageways through the pipewall substantially aligned axially along the top of the pipe member, an elongated trough-shaped deflection shield positioned over the passageways with its convex portions facing upwardly, an elongated adjustable slit opening between an edge of the deflection shield and the outside of the pipe member, a spillway for delivering liquid in the form of a thin flowing sheet from the slit opening to a receiving surface, means for supplying liquid under pressure to the inside of the pipe member, and means for adjusting the thickness of the slit opening. In specific embodiments of this invention, the deflecting shield is attached to the outside of the pipe member by a hinge along the edge opposite to the edge forming the slit opening and is sealed to the outside of the pipe member so that liquid can flow outwardly only through the slit opening. In another embodiment of this invention the inside of the pipe member includes baffles to divert the flow of liquid through the pipe member and thereby to control its velocity.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a partial cross sectional view showing the use of a plurality of liquid distribution devices of this invention to wash a wet pulp sheet in the paper making industry.
FIG. 2 is a front elevational view of the liquid distribution device of this invention.
FIG. 3 is a partial cross sectional view taken at 3--3 of FIG. 2.
FIG. 4 is a cross sectional view taken at 4--4 of FIG. 3.
FIG. 5 is a cross sectional view taken at 5--5 of FIG. 3.
FIG. 6 is a cross sectional view taken at 6--6 of FIG. 2.
FIG. 7 is a cross sectional view taken at 7--7 of FIG. 2.
FIG. 8 is a view similar to that of FIG. 7 showing the opening of the hinged deflecting shield.
FIG. 9 is a cross sectional view taken at 9--9 of FIG. 2.
FIG. 10 is a cross sectional view taken at 10--10 of FIG. 7.
FIG. 11 is a partial top plan view taken at 11--11 of FIG. 8.
FIG. 12 is a partial cross sectional view taken at 12--12 of FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
The use of the device of this invention in the pulp paper industry is shown in FIG. 1. A large pulp sheeting drum 20 is partially submerged in an aqueous pulp dispersion 21 and continuously rotated in the direction of arrow 22 while suction is applied from the interior of drum 20. This forms a thin sheet 24 of pulp on drum 20 which must be washed dried and pressed to eventually become a sheet of paper. Five water showering devices 23 of this invention are shown employed in series to provide the washing operation necessary to clean the pulp as it is formed into a sheet. Each showering device 23 comprises a pipe header 25 into which wash water flows to form a reservoir. Water from header 25 flows through small passageways from header 25 into deflector shield 34 and out through a slit orifice onto distribution plate 38 which conducts the wash water in the form of a thin sheet onto the pulp sheet 24 passing by on drum 20.
The details of the showering device of this invention are seen in FIGS. 2-12. The main body and supporting structure of the device of this invention is a large pipe 25 forming a header or a reservoir when it is filled with necessary liquid being distributed, which in the case of the pulp and paper industry is wash water. Liquid enters pipe 27 passing through flange assembly 26 through the interior portion of header 25 and eventually exits through flange assembly 28 and output pipe 29. In order to control the velocity of the wash water passing through header 25 it has been found desirable to employ a plurality of lateral baffles 31 and 32 to divert the liquid flow laterally and thus permit a better control of the overall velocity of liquid through header 25. In this embodiment of the invention baffles 31 and 32 are supported by a central rod 30 which is welded or otherwise fastened to the interior of header 25 at 33. The baffles employed may be any design of lateral obstruction to prevent a central core of liquid from flowing rapidly through header 25 from inlet to outlet. In the drawings of this invention there are shown baffles comprising a central disk 41 supported by a plurality(three in this instance) of spaced legs positioned approximately at equal angles to each other. Plate 41 can be pierced centrally with a drilled hole 43 as shown in FIG. 4 so that it may slide over central support rod 30 and be positioned wherever desired in the length of header 25. First baffle 31 need not be pierced centrally with a hole but can be fashioned to receive the end of support rod 30 in a central clearance 44 formed by the interior ends of spacer legs 42. Preferably each of the baffles 31 and 32 is welded to rod 30 to maintain it in its selected position.
Wash water passing through the interior of header 25 enters cover or deflecting shield 34 through a plurality of spaced passageways 37 through the wall of header 25. Preferably deflecting shield 34 is placed on the top of horizontally positioned header 25, and therefore, passageways 37 can be a series of holes aligned generally along an axial direction and spaced apart from each other so as to provide a communication from the interior of header 25 to the interior of deflecting shield 34. Deflecting shield 34 is generally a trough-shaped elongated member with its concave side facing downwardly against the outside of header 25 and its closed convex portion facing upwardly. Along its rear edges deflecting shield 34 is attached to the outside of header 25 by a plurality of hinges 35. Along the front edge of deflecting shield 34 there is an adjustable slit opening between the edge of deflecting shield 34 and the outside surface of header 25 which, in effect, is an orifice for the wash water causing it to form a thin sheet of liquid. This sheet of liquid is then conducted along a distribution plate 38 to a surface for receiving that liquid. Deflecting shield 34 is adjusted with respect to the slit opening by means of a clamp 36 attached at each end of deflecting shield 34. By having passageways 37 at the top of a horizontal header 25 there is less chance for any passageways 37 to become plugged by solid materials that may be in the liquid which would normally tend to settle to the bottom of header 25 by reason of gravity. Hinge 35 makes it possible, when clamping means 36 are released, to pivot deflecting shield 34 around the hinge pin and permit rapid and easy cleaning of any passageway 37 that may be obstructing the normal flow of liquid.
In FIG. 6 there is shown a section through flange assembly 28 indicating that it comprises the normal arrangement of a series of bolts 39 and nuts 40. Outlet 29 is shown as a reduced section tapering down from the enlarged diameter of header 25. In a typical washing operation in the pulp and paper industry header 25 may be approximately 4 inches in diameter while outlet 29 may be 21/2 inches in diameter.
In FIGS. 7-10 some of the features of the showering device of this invention are shown. Deflecting shield 34 is a trough-shaped member having end plates 55 which thereby define an enclosed space for receiving liquid from passageways 37. The only outlet from the enclosed space within deflecting shield 34 is a narrow slit opening 54 which permits the liquid inside of deflecting shield 34 to flow outwardly in the form of a thin sheet of liquid onto distribution plate 38 which, in turn, conducts the liquid to the surface receiving that liquid, e.g. pulp sheet 24 on drum 20 as shown in FIG. 1. The remaining edges around deflecting shield 34 are sealed to prevent any substantial leakage of liquid except that through slit opening 54. For example the back side of deflecting shield 34 is attached to the outside surface of header 25 by means of hinge 35. There must be a clearance between header 25 and deflecting shield 34, along the pivot axis. The means to prevent leakage between the header 25 and that portion of deflecting shield 34 is a flexible seal 52 which may be made of rubber or other similar material that will prevent the leakage of liquid out of the lower back edge of shield 34 where it joins the outside surface of header 25. In order to maintain seal 52 in its desired position it is preferred to employ L-shaped support 53 which is welded or otherwise fixed to the inside surface of deflecting shield 34. At the two ends of deflecting shield 34 are end plates 55 which slide snugly against seal plates 56 attached to the outside surface of header 25. There is no need normally to employ any resilient seal between these two plates since the pressures involved are small enough that only a minimum leakage may occur between these two plates 55 and 56. The forward edge of deflecting shield 34 is made to be adjustable with respect to the outside surface of header 25 or to the surface of distribution plate 38 when such is employed. In the instance shown in FIG. 9 distribution plate 38 extends upwardly sufficiently far to cooperate with the forward edge of deflecting shield 34 in forming the slit opening 54 which functions as an orifice for the liquid distributed onto plate 38. Preferably several stiffening gusset plates 58 are employed in spaced relationship to each other to maintain the forward edge of deflecting shield 34 parallel to distributing plate 38 when deflecting shield 34 is long, i.e. at least about 4 feet. In the paper pulp industry sheet forming drums (20 in FIG. 1) are 16 feet long and therefore several gusset plates 58 are required for deflection shield 34 on a washing device of this invention which necessarily would also be 16 feet long.
The mechanism which is shown here for adjusting the width of slit opening 54 comprises a bolt 45 welded to a pivot pin 46 which is pivotally mounted in supports 49 attached to the outside of header 25. Slotted arm 51 is attached to the end plate 55 of deflecting shield 34. Adjustment of clamp nut 48 and wing nut 47 on the threaded section of bolt 45 causes slit opening 54 to narrow or to widen respectively. Bolt 45 is mounted on a pivot pin 46 so that when it is important to uncover passageways 37 for cleaning or inspection it may be done readily. As shown in FIG. 8 wing nut 47 may be unloosened and bolt 45 pivoted outwardly releasing it from the slot in arm 51. This releases deflecting shield 34 so that it may be opened by pivoting around hinge 35.
In FIGS. 11 and 12 passageways 37 are shown as drilled holes which have been countersunk or chamfered to remove any burrs that might otherwise snag dispersed particles in the liquid and cause plugging of the passageway.
In a test to indicate the improvement in delivery of water from the device of this invention as compared to one which did not include baffles in header such as those shown at 31 and 32 in FIG. 3 the following data were obtained. In the absence of baffles there is considerably larger volume of flow from the passageways near the outlet of header 25 as compared to those near the inlet of header 25. In contrast, when baffles were employed as shown in FIG. 2 in these drawings the following flow data were obtained from each of 16 passageways spaced 1 foot apart along a header 16 feet in length. The flow rates were measured at incicated pressures of zero and 1.2 on a pressure gauge. As seen in Table 1 below the values of flow in the device of this invention were substantially the same from one end of the long header to the other.
TABLE 1______________________________________Passageway Flow in Gal. /MinPosition 0 psig. 1.2 psig.______________________________________1 10.44 14.362 11.52 16.503 12.96 16.254 11.52 15.755 11.52 16.666 9.64 17.007 10.08 16.528 10.64 16.509 10.64 16.6610 10.08 15.5011 10.08 15.2512 11.52 16.3013 11.52 16.3014 11.52 16.3015 11.52 16.3016 11.52 16.30Total Flow 176.72 258.45______________________________________
Tests were made comparing a whistle shower device (well known in the pulp and paper industry) to the device of this invention. It was found that the whistle shower device caused a 4° F. temperature drop to occur in the water from the time it was inside the header to the time it contacts the wet pulp sheet. Under the same conditions the device of this invention produced only a 1° F. temperature drop. If these energy savings are applied to a plant unit delivering 800 gallons per minute of wash water it would result in savings of over $45,000 per year. It should be readily apparent from these tests that the device of this invention exhibits considerable improvement over those of the prior art.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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A liquid distribution device comprising a tubular horizontal reservoir for holding liquid to be distributed, a plurality of passageways through the upper wall of the reservoir and communicating with an elongated space substantially enclosed by an elongated arcuate cap member extending lengthwise along the outside of the tubular reservoir, the cap member having an outlet edge which is adjustable with respect to the outside surface of the reservoir to produce an elongated narrow slit outlet through which the liquid can flow in the form of a thin sheet. This device finds its principal use in delivering wash liquid to a wet sheet of paper pulp.
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This is a continuation of application Ser. No. 08/534,863 filed Sep. 27, 1995 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multichip module having a plurality of semiconductor chips on a substrate, particularly to an improved cover structure for covering the semiconductor chips.
2. Description of the Prior Art
As the development of large-scale integrated circuit (LSI) technology has been made, it is becoming an increasingly important problem to improve the packaging density on a printed circuit board. As a method for improving the packaging density, attention has focused on a multichip module in which a plurality of LSI chips are mounted on a substrate.
FIG. 1 is a schematic sectional view showing a conventional multichip module. A plurality of semiconductor chips 2 are joined by a sealing resin 3 on a substrate 1. The bumps of the semiconductor chip 2 are electrically connected to the connection terminals formed on the substrate 1, respectively. The semiconductor chips 2 on the substrate 1 are covered with a cover 4 which is secured at the peripheral area of the substrate 1. A heat conductive resin 5 is provided between the ceiling of the cover 4 and the upside of each semiconductor chip 2 and the heat generated by the semiconductor chip 2 is released through the heat conductive resin 5 and the cover 4.
The official gazette of Japanese patent Laid-Open No. 1 90712/1993 discloses a structure in which one heat sink is brought into contact with the upside of a plurality of semiconductor chips and the outer periphery of the heat sink is joined with a substrate by a sealing material.
However, the conventional structures as described above have a problem that the substrate is deformed due to the difference in CTE (coefficient of thermal expansion) between the cover (or the heat sink) and the substrate and resultingly, the connection reliability and the cooling performance of semiconductor chips are deteriorated. More specifically, in the case of the structure shown in FIG. 1, the thermal-expansion displacement of the substrate directly deforms the substrate because the periphery of the cover 4 is secured to the substrate 1. For example, since a substrate with a length of 40 millimeter would have a thermal-expansion displacement of approx. 24 micrometer, a vertical displacement of up to approx. 0.5 millimeter occurs due to the difference in CTE between the substrate 1 and the cover 4. When the vertical displacement approaches the above value, the heat conductive resin 5 cannot absorb the displacement and it comes off the semiconductor chip 2 or the cover 4 to cause the performance for cooling the semiconductor chips 2 to greatly deteriorate. To avoid such a disadvantage, it is necessary to equalize the CTE of the cover 4 with that of the substrate 1 and therefore, material selection is greatly restricted.
Moreover, the heat sink disclosed in the official gazette of Japanese Patent Laid-Open No. 190712/1993 is comprised of metal bodies insulated from each other through an insulator, it is more difficult to equalize the CTE of the heat sink with that of the substrate. Therefore, the structure where the substrate and the heat sink are secured at the periphery thereof causes the substrate to be deformed due to a temperature change under the presence of the CTE difference, and thereby a shearing stress occurs at bump joints of each semiconductor chip, causing the connection reliability and the cooling performance of the chip to deteriorate.
A structure is known in which cooling means such as a heat spreader or a large heat sink is set on each semiconductor chip. However, the structure requires a large space and moreover, an excessive force may be applied to the semiconductor chip. Further, it is a larger problem that the substrate cannot be mounted on a mother board by using a suction hand for mounting because the upside of the substrate is irregular or uneven due to semiconductor chips.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a semiconductor-chip cover structure making it possible to prevent a substrate from deforming due to a temperature change and connect semiconductor chips at a high reliability.
It is another object of the present invention to provide a semiconductor chip module making it possible to efficiently cool semiconductor chips in a small space independently of a temperature change.
The multichip module according to the present invention is comprised of a substrate mounting a plurality of semiconductor chips, a plate positioned over the semiconductor chips, and at least one pillar member for connecting the plate with the substrate with supporting the plate. The substrate has a plurality of circuit chips fixed in a predetermined pattern of locations on a side thereof. Each circuit chip is electrically connected to electrodes of the substrate. The plate, or a covering member, covers the circuit chips, comprising one or more plate element. At least one pillar member fixes the covering member to the substrate such that the covering member is positioned over the circuit chips. Since the pillar member is fixed to the substrate at a small area to support the covering member, the substrate can be prevented from deforming due to a temperature change. In order to secure the covering member, the pillar member is preferably fixed by means of an adhesive, a fit, or screwing.
Preferably, a heat conductive member, having flexibility, is provided between the covering member and the upside of each circuit chip in contact with the both. The heat produced by each circuit chip is conveyed to the covering member through the heat conductive member and then diffused into air. More preferably, a heat spreader is provided between the heat conductive member and the upside of each circuit chip in contact with the both. A fin structure may be employed in the covering member, resulting in increased cooling performance. The covering member is preferably circular.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing the schematic structure of a conventional multichip module;
FIG. 2 is a schematic sectional view showing the structure of the first embodiment of the multichip module of the present invention;
FIG. 3 is a top view of the first embodiment shown in FIG. 2;
FIG. 4 is a schematic sectional view showing the structure of the second embodiment of the multichip module of the present invention;
FIG. 5 is a schematic sectional view showing the structure of the third embodiment of the multichip module of the present invention; FIG. 6 is a schematic sectional view showing the structure of the fourth embodiment of the multichip module of the present invention;
FIG. 7 is a top view of the fourth embodiment shown in FIG. 6;
FIG. 8 is a top view of the fifth embodiment of the multichip module of the present invention;
FIG. 9 is a schematic sectional view showing the structure of the sixth embodiment of the multichip module of the present invention;
FIG. 10 is a schematic sectional view showing the structure of the seventh embodiment of the multichip module of the present invention;
FIG. 11 is a schematic sectional view showing the structure of the eighth embodiment of the multichip module of the present invention; and
FIG. 12 is a top view of the eighth embodiment shown in FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 2 and 3, four semiconductor chips 102 each having bumps 103 at predetermined positions are arranged on a substrate 101 and each of the chips 102 is secured to the substrate 101 by a sealing resin 104. The arrangement of the chips 102 may be symmetrical about the center of the substrate 101. A cover 105 having the same shape as the substrate 101 is provided with a support pillar 106 at the central portion thereof and the support pillar 106 is secured to the center (or center of gravity) of the substrate 101 by an adhesive 107. It is possible to integrally form the cover 105 and the support pillar 106 in one piece or secure the support pillar 106 to the flat cover 105. The cover 105 is located above all semiconductor chips 102 to shield them. Moreover, chip connection terminals (not illustrated) for electrically connecting with the bumps 103 are formed on the side of the substrate 101 for arranging the semiconductor chips 102, and external connection terminals 108 are formed on the back surface of the substrate 101, and the chip connection terminals and the external connection terminals 108 are electrically connected to each other by interconnections (not illustrated). To mount this type of the multichip module on a mother board, it is only necessary to set a suction hand to a position nearby the center of the cover 105.
The substrate 101 is comprised of the chip connection terminals, the external connection terminals 108, and an insulator with wiring formed on it. The insulator may use an organic material such as glass epoxy, paper phenol, BT resin, or polyimide or a ceramic material such as glass ceramics. The material of the cover 105 is selected in view of lightness, durability, and heat-radiative property. For example, it is possible to use a metallic material such as aluminum, an aluminum alloy, or copper for the cover 105. Particularly, copper is preferable in view of heat-radiative property because of a high heat conductivity. A thermosetting resin may be used in view of lightness.
This embodiment is manufactured in accordance with the following steps. First, the semiconductor chip 102 is connected onto the glass epoxy substrate 101 by means of flip-chip bonding to seal the gap between the semiconductor chip 102 and the glass epoxy substrate 101 by the epoxy-based sealing resin 104. Then, the support pillar 106 of the aluminum cover 105 is bonded to the central portion of the substrate 101 by the adhesive 107 to secure the cover 105.
By setting the support pillar 106 for securing the cover 105 to the substrate 101 at the center (or center of gravity) of the substrate 101, it is possible to minimize a stress caused by a CTE difference between the cover 105 and the substrate 101. This stress reduction effect is described below in detail.
As an example, a multichip module is taken in which the substrate 101 made of glass epoxy (CTE: 30 ppm), the cover 105 and the support pillar 106 are made in one piece of aluminum (CTE: 20 ppm), and the diameter of the support pillar 106 is 3 mm. Since the temperature of the semiconductor chip 102 rises up to 85° C. in an actual operational environment in general, the aluminum cover 105 expands by approx. 0.13% and the glass epoxy substrate 101 expands by approx. 0.2%, compared to the length at room temperature, respectively. When assuming the temperature difference from the room temperature to be 60° C., a displacement of approx. 2 μm occurs nearby the support pillar 105 with the diameter of 3 mm. Therefore, the stress caused by a CTE difference between the cover 105 and the substrate 101 is greatly reduced compared with the case of the conventional structure shown in FIG. 1. Moreover, since the edges of the cover 105 are opened, expansion and deformation due to a temperature rise are freely made and no stress occurs to the substrate 101. In short, even if the cover 105 is made of a material with a CTE different from those of the substrate 101 and semiconductor chip 102, it does not cause a stress in the substrate 101 and the semiconductor chip 102.
FIG. 4 shows a second embodiment of the present invention. In the case of this embodiment, the cover 105 is secured by inserting the support pillar 106 of the cover 105 into a securing hole 109 which is formed at the central portion of the substrate 101. In order to secure the support pillar 106 firmly, the diameter of the cover securing hole 109 is set at a value smaller than that of the support pillar 106 by approx. 0.05 mm. In the case of this embodiment, the cover 105 is secured only by inserting the support pillar 106 of the cover 105 into the securing hole 109, resulting in the simplified manufacturing steps and the reduced manufacturing cost. FIG. 5 shows a third embodiment of the present invention. In the case of this embodiment, the front end of the support pillar 106 is formed into a threaded structure and a cover securing threaded hole 110 is formed at the central portion of the substrate 101. Moreover, the cover 105 is secured by screwing the support pillar 106 of the cover 105 into the securing threaded hole 110. In the case of this embodiment, the cover 105 can further firmly be secured by using the threaded structure. Moreover, the manufacturing steps are simplified and the manufacturing cost is decreased because the cover 105 can be set only by screwing the support pillar 106 of the cover 105 into the securing threaded hole 110 of the substrate.
FIGS. 6 and 7 show a fourth embodiment of the present invention. Among five semiconductor chips 202 each having bumps 203 electrically connected to a substrate 201, four semiconductor chips are adjacently arranged on four sides of a semiconductor chip 202a as shown in FIG. 7. The arrangement of the five chips 202 may be symmetrical about the center of the substrate 201. Each semiconductor chip 202 is secured to the substrate 201 by a sealing resin 204. Four support pillars 206 are set to a cover 205 having the same shape as the substrate 201 and secured by an adhesive 207 so as to surround the semiconductor chip 202a at the center of the substrate 201. The four support pillars 206 are arranged at the central portion of the cover 205 so that their intervals are minimized. The reason is that it is possible to decrease the stress caused by a CTE difference between the substrate 101 and the cover 205. In the case of this embodiment, the four pillars 206 are arranged nearby four corners of the central semiconductor chip 202a as shown in FIG. 7. It is also possible to integrate the cover 205 and the four support pillars 206 in one piece or fix the four support pillars 206 to the flat cover 205.
The cover 205 is located above all semiconductor chips 202 to shield them. Moreover, chip connection terminals (not illustrated) electrically connecting with the bumps 203 are formed at one side of the substrate 201 for arranging the semiconductor chips 202, and external connection terminals 208 are formed at the back surface of the substrate 201, and the chip connection terminals and the external connection terminals 208 are electrically connected by interconnections (not shown). To mount this type of the multichip module on a mother board, it is only necessary to put a suction mounting hand onto a position nearby the center of the cover 105.
The substrate 201 is comprised of the chip connection terminals, the external connection terminals 208, and an insulator with wiring formed on it. The insulator uses an organic material such as glass epoxy, paper phenol, BT resin, or polyimide or a ceramic material such as glass ceramics. The material of the cover 205 is selected in view of lightness, durability, and heat-radiative property. For example, it is possible to use a metallic material such as aluminum, an aluminum alloy, or copper for the cover 205. Particularly, copper is preferable in view of heat-radiative property because of a high heat conductivity. A thermosetting resin may be used in view of lightness.
This embodiment is manufactured in accordance with the following steps. First, the semiconductor chip 202 is connected onto the glass epoxy substrate 201 by means of flip-chip bonding to seal the gap between the semiconductor chip 202 and the glass epoxy substrate 201 by the epoxy-based sealing resin 204. Then, the support pillar 206 of the aluminum cover 205 is bonded to the central portion of the substrate 201 by the adhesive 207 to secure the cover 205.
FIG. 8 shows a fifth embodiment of the present invention. In the case of a cover 105 of this embodiment, a handling area 301 is formed at the central portion and openings 302 are formed at other portions. The arrangement of the openings 302 may be symmetrical about the central point of the support pillar 106. As is the case with the first embodiment shown in FIGS. 2 and 3, the cover 105 is secured to the substrate 101 by means of the support pillar 106. To mount the embodiment on a mother board, it is only necessary to move the multichip module by sucking the handling area 301 of the cover 105. The weight of the cover 105 is greatly decreased by forming the openings 302 at the areas other than the central handing area 301.
FIG. 9 is a sectional view showing a sixth embodiment of the present invention. Four semiconductor chips 402 each having bumps 403 are symmetrically arranged on a substrate 401 and each chip 402 is secured to the substrate 401 by a sealing resin 404. A cover securing pillar 406 is provided at the central portion of the cover 405 and is secured to the center (or center of gravity) of the substrate 401. To secure the cover securing pillar 406 to the substrate 401, an adhesive, a fit or screwing can be employed as described in FIGS. 3 to 5. Moreover, this embodiment has a structure in which the cover securing pillar 406 is secured to the cover 405. However, it is also possible to use a structure in which the cover 405 is integrated with the cover securing pillar 406 in one piece. A heat conductive resin 501 is provided between the cover 405 and the upside of the semiconductor chip 402 in contact with the both. The heat produced by the semiconductor chip 402 is conveyed to the cover 405 through the heat conductive resin 501 and then diffused into air.
In addition, chip connection terminals (not illustrated) electrically connecting with the bumps 403, respectively, are formed at the side of the substrate 401 for arranging the semiconductor chips 402, and external connection terminals 407 are formed at the back surface of the substrate 401, and the chip connection terminals and the external connection terminals 407 are electrically connected by interconnections (not illustrated). To mount this type of the multichip module on a mother board, it is only necessary to put a suction mounting hand to a position nearby the center of the cover 405.
The substrate 401 is comprised of the chip connection terminals, the external connection terminals 407, and an insulator with wiring formed on it. The insulator uses an organic material such as glass epoxy, paper phenol, BT resin, or polyimide or a ceramic material such as glass ceramics. The material of the cover 405 is selected in view of lightness, durability, and heat-radiative property. For example, the cover 405 can use a metallic material such as aluminum, an aluminum alloy, or copper. Particularly, copper is preferable in view of heat-radiative property because it has a high heat conductivity. A thermosetting resin may be used in view of lightness.
The heat conductive resin 501 can use a compound made by dispersing fillers with a high heat conductivity (e.g . . . silver, alumina, diamond, silicon carbide, or boron nitride) into a silicone resin, or a silver epoxy resin or silicon rubber. Since these materials are superior in flexibility, they can easily absorb the deformation or irregularity of the surface of the semiconductor chip 402 or the cover 405.
This embodiment is manufactured in accordance with the following steps. First, each semiconductor chip 402 is connected onto the glass epoxy substrate 401 by means of flip-chip bonding to seal the gap between the semiconductor chip 402 and the glass epoxy substrate 401 with the epoxy-based sealing resin 404. Then, the heat conductive resin 501 is put on the upside of each semiconductor chip 402 and the cover securing pillar 406 is secured at the central portion of the substrate 401 so as to shield the heat conductive resin 501 with the aluminum cover 405.
By setting the cover securing pillar 406 for securing the cover 405 to the substrate 401 at the center (or center of gravity) of the substrate 401, it is possible to minimize the stress caused by a CTE difference between the cover 405 and the substrate 401. Particularly, because the flexible heat conductive resin 501 is present between the semiconductor chip 402 and the cover 405, an expansion of the cover 405 due to a temperature change is absorbed by deformation of the heat conductive resin 501 or slip between the cover 405 and the heat conductive resin 501 and thereby, no stress is applied to the semiconductor chip 402.
Moreover, by using a conductive material for the heat conductive resin 501 and forming the cover 405 and the cover securing pillar 406 with copper, it is possible to connect the upside of the semiconductor chip 402 to the minimum potential of the wiring substrate 401. More specifically, a conductive pattern connected to the minimum potential is formed at a joint between the substrate 401 and the cover securing pillar 406 and the cover securing pillar 406 is secured to the substrate 401 so as to electrically connect with the conductive pattern. Since the heat conductive resin 501 is conductive, the upside of the semiconductor chip 402 can be kept at the minimum potential of the circuit. This structure is necessary to perform stable operations for a certain type of an integrated-circuit chip.
It is apparent that the above-mentioned structure in which the heat conductive resin is provided on each semiconductor chip may be also employed in the 5-chip structure as shown in FIGS. 6 and 7.
FIG. 10 is a sectional view showing a seventh embodiment of the present invention. In the case of this embodiment, a heat spreader 502 is secured to the upside of each semiconductor chip 402 and a heat conductive resin 503 is provided between the heat spreader 502 and the cover 405 in contact with the both. Moreover, in the case of this embodiment, the cover 405 is integrated with the cover securing pillar 406 in one piece.
The heat produced by the semiconductor chip 402 is diffused by the heat spreader 502, conveyed to the cover 405 through the heat conductive resin 503, and diffused into air. When the semiconductor chip 402 is relatively small in size but it has a large heating value, it is effective to use the heat spreader 502. The heat spreader 502 has a heat resistance much smaller than that of the heat conductive resin 503. Therefore, the spreader 502 improves the cooling effect because heat quickly diffuses and a heat releasing area expands. The material of the heat spreader 502 uses a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or copper tungsten, or ceramics such as aluminum nitride.
By using aluminum nitride serving as an insulator for the heat spreader 502, it is possible to electrically insulate the upside of the semiconductor chip 402 from the cover 405. This type of the heat spreader 502 is effective when a power-supply voltage Vcc is connected to the upside of the semiconductor chip 402 and the cover 405 is grounded.
FIG. 11 is a sectional view showing an eighth embodiment of the present invention. FIG. 12 is a top view of this embodiment. A cover 601 of this embodiment has a heat-releasing fin structure in which a plurality of stages of circular metallic plates 603a to 603c are arranged in parallel about the cover securing pillar 602. The fin-structure cover 601 shields over the semiconductor chips 402 with the cover securing pillar 602 secured to the center of the substrate 401. In this case, since the cover 601 is circular, it is unnecessary to consider the setting direction of the cover 601 and therefore, the step of setting the cover 601 is simplified. When the cover 601 is secured to the substrate 401, the downside of the circular metallic plate 603a at the lowest stage contacts the heat conductive resin 501 provided at the upside of the semiconductor chip 402. The material of the cover 601 uses aluminum, an aluminum alloy, or copper.
The heat produced by the semiconductor chip 402 is conveyed to the lowest-stage metallic plate 603a of the cover 601 through the heat conductive resin 501 and further, conveyed to the upper-stage metallic plates 603b and 603c and diffused into air. Since the cover 601 has a heat-releasing fin structure, a large heat-releasing effect can be obtained. Moreover, since the fin-structure cover 601 is secured to the substrate 401 by the cover securing pillar 602, the weight of the cover 601 is not applied to the semiconductor chip 402. Therefore, it is easy to increase the size of a heat-releasing fin or heat sink. In particular, because one heat sink is set onto a plurality of semiconductor chips 402, turbulence of air flow hardly occurs and the cooling effect can easily be improved. Moreover, as described above, deformation of the substrate 401 due to a CTE difference between the cover 601 and the substrate 401 is greatly decreased compared to the conventional one.
It is apparent that the above-mentioned cover structure as shown in FIGS. 11 and 12 may be also employed in the 5-chip structure as shown in FIGS. 6 and 7.
As described above in detail, the multichip module of the present invention has a structure in which a flat cover is joined with a substrate by at least one support pillar. Therefore, it is possible to greatly decrease the deformation due to a CTE difference between the cover and the substrate and greatly improve the connection reliability of semiconductor chips mounted on the substrate.
Moreover, since a structure is used in which a semiconductor chip contacts a cover through a flexible heat conductive resin, it is possible to efficiently release heat without applying a dynamic load to the substrate. Particularly, because the cover is joined with the substrate only by the support pillar, it is possible to form the cover into a heat sink structure for releasing heat and easily improve the chip cooling performance without applying an unnecessary force to the semiconductor chip.
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A multichip module comprises a substrate mounting a plurality of circuit chips, a cover plate positioned over the circuit chips, and at least one pillar member for fixing the cover plate to the substrate to support it. The substrate has a plurality of circuit chips fixed in a predetermined pattern of locations on a side thereof. At least one pillar member fixes the cover plate to the substrate such that the cover plate is positioned over the circuit chips. Since the pillar member is fixed to the substrate at a small area to support the cover plate, the substrate can be prevented from deforming due to a temperature change. In order to secure the covering member, the pillar member is preferably fixed by means of an adhesive, a fit, or screwing.
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BACKGROUND OF THE INVENTION
The invention relates to a device for intermingling a bundle of wet threads of smooth multifilament in a turbulent air stream. The device includes a nozzle body with U-shaped thread channels and a centered inlet or bore hole for compressed air assigned to each thread channel. The invention further relates to a process for intermingling the bundle of threads in a turbulent air stream.
In order to obtain good weaving properties of smooth textile multifilament threads, a sizing is usually required. Intermingling the threads in a turbulent air stream supports the sizing effect so that the weaving properties are improved or the degree of sizing can be maintained at a lower level. The turbulent air stream treatment serves to keep the fibrils close enough to each other so as to permit a gluing by the sizing agent. Weak knots of air serve this purpose, especially if the turbulent air stream treatment is performed directly before the sizing trough, since there is little stress applied to the threads and only a few knots are lost. Weak knots of turbulent air in short, regular distances are more appropriate than stronger knots in larger and thus irregular distances. Stronger knots also present the risk of showing traces in the fabric.
The knots can be influenced by the diameter of the thread channel. A large thread channel results in tight knots of air in relatively large distances; a small diameter results in more loose knots in smaller, more regular distances.
Stretch-sizing of multifilament threads made of thermoplastics, especially made of polyamide and polyester but also polyethylene and polypropylene, employs a wet thread which is treated in a turbulent air stream between a stretching trough, usually containing water, and a sizing trough; the adherent water is blown off during the air stream treatment using a suitable device.
The diameter of the thread channel influences the air stream treatment; while it has to be narrow to blow off the water with a minimum of air, there is a restriction in selecting the kind of turbulent air stream treatment of wet threads. While relatively loose knots are sufficient to support the sizing effect, this will not be a disadvantage to the stretch sizing, where the threads are hardly exposed to stress between the turbulent air stream treatment and the sizing trough.
Devices for intermingling a bundle, of threads made of dry filament threads in a turbulent air stream are known (U.S. Pat. No. 4,644,622). The known device includes a rotatable nozzle body, provided with tube-like turbulence nozzles each having a slot; these nozzles are closed during operation. The thread guiding channel is rectangular, and the thread is guided diagonally in this thread channel. This device is appropriate for the treating of certain titers of dry threads in a turbulent air stream during the warping or stretch-warping process. There is no information provided on the efficiency and the turbulence device and its air consumption. A disadvantage is the time-consuming inserting of the bundle of threads.
From the EP-A 0 121 010 a turbulence device with turbulence nozzle is known for the manufacture of an interlaced yarn. The device is equipped with a U-shaped turbulence channel. Although the turbulence improved, the consumption of compressed air is still much too high.
EP-A 0 144 617 describes a process for the manufacture of a chain which includes stretching in a water bath, followed by a turbulent air stream treating, and a subsequent sizing process. The description does not give any details on the kind of turbulence involved.
It is a disadvantage of the known wet stretching process that the liquid adherent to the thread must be mostly removed before entering the turbulent air stream device in order to prevent a dilution of the sizing liquor. This is achieved by an upstream system of squeeze rolls. A squeezer disposed downstream of the stretching trough removes the water only insufficiently, i.e., only about 50% of the water is removed.
All known nozzles have disadvantages. They use too much air or damage the thread. Most of the turbulence nozzles operate with dry threads, achieving satisfactory results in a certain titer range. Employing wet threads, however, leads to a rapid efficiency decrease due to the fact that the water is removed insufficiently, resulting from an insufficient turbulence of the bundle of threads.
Another disadvantage of the known turbulence devices is that each individual thread must be carried into the eyes and combs before and after the thread channels, which is very time-consuming.
SUMMARY OF THE INVENTION
It is the object of the invention to create a device for intermingling a bundle of filament threads, especially while employing stretch sizing, in a turbulent air stream; the device ensures a correct turbulence without damaging the thread while the surface water is removed at a low air consumption rate.
It is furthermore an object of the invention to provide a process which permits the turbulent intermingling of a large number of threads and avoids the insertion of the individual threads into the eyes. The thread density (threads/cm) must remain constant before and after the turbulence device.
The nozzle body is provided with at least two U-shaped thread channels and a borehole in the support area for a removable cover. Each thread channel represents in cross-section view a semicircular section of radius r and a rectangular section of width 2r and height r.
It proved to be advantageous to provide the thread channel with a cover. The cover can be removed for easy insertion. The air borehole shall be provided in the middle of the thread channel.
If the air speed within the thread channel is high enough, the major part of the surface water is blown off in counterdirection to the thread movement, hence, the central air borehole can be considered to be the place of separation between the wet area and the dry area. The exiting thread is completely free of surface water and feels dry.
It is particularly advantageous that the bottom part of the thread channel, provided with a rectangular centered air channel, has a semicircular cross section. The thread can be guided in the center of a circle while the lumen of the circle is not narrowed by a flat cover. Furthermore, this configuration of the nozzle body has significant advantages from a manufacturing point of view. Employing simple tools, an exact thread channel without sharp edges can be produced by means of milling.
A further embodiment features a thread channel with narrowed ends at the thread inlet and outlet, permitting a better liquid drainage of the wet thread. If the thread channel is narrow at its inlet and outlet but broader in the middle, there is sufficient space for a turbulent air stream treating and the water can still be blown off by the high air speed.
The cover is advantageously made of a metal plate with a thickness of 30-50 mm, preferable 40 mm, with plane-parallel surfaces. It can be removed, pivoted, or slid to expose the thread channel to permit inserting the bundle of threads. The flat closure has the advantage that it can be manufactured simply and that it fits well. Boreholes or recesses to supplement the thread channel in the nozzle body are not necessary. Hence, a complicated cover configuration is not required.
The cover closure is monitored advantageously by means of compressed air via a check borehole in the nozzle body. If the cover fits correctly, compressed air cannot escape through this borehole. The cover is held fast by its own weight (40 mm steel), since there is not enough space left to fasten it between the thread channels.
It is advantageous to restrict the length of the thread channel to 3 to 12 cm, while a length between 3 and 10 cm is preferred. The best results are achieved with a thread channel length of 10 cm. The diameter of the thread channel, however, is significant and lies between 1.5 and 2.5 mm. It is advantageous to select a diameter of 2.2 to 2.5 mm for coarse fibril titers ranging from 5 to 7 dtex, and a diameter of 1.5 to 2.0 mm for fine fibril titers, e.g. up to 3.5 dtex. In order to ensure a sufficiently intensive turbulent air stream treating of a thread, e.g. dtex 167 f 30, 5.6 dtex/fibrils, a thread channel diameter of more than 2 mm is required.
If a thread channel is too large, the turbulence is bad, the watery liquid is not blown off, and the water which is adherent to the thread coming from the stretching trough then strongly dilutes the subsequent size. If the turbulence is bad, the distance between the knots increases, thus creating more and more open spaces which finally reduce the running properties of the threads. If the thread channel is too narrow, depending on the fibril titer, the turbulence of the bundle of threads is also reduced. Knots at 167 f 30, for example, with a thread channel of less than 2 mm diameter are so weak that the needle method cannot be applied anymore.
Hard anodized aluminum proved to be a particularly suitable material for the nozzle body with the thread channel. Chemical polishing before the anodic oxidation can prevent serimetry damages which occur during the turbulence. A black coloring also permits a particular visibility of a white thread. It is advantageously that the anodizing layer have a thickness of about 50 um which ensures a long life. The thread channels can be inspected for cleanliness and general condition.
It is also advantageous to offset the nozzle bodies below each other in direction of the thread movement so that the blown off water fall back onto the wet incoming threads and not on the already dried threads.
Each individual thread of a bundle of threads consisting of filament threads is directed parallel to the longitudinal axis of the turbulence chamber; the turbulence is performed at 100 to 600 m/min, preferably at 200 to 400 m/min while the speed is determined by the sizing process. According to titer and number of knots/m, the relative air consumption is less than 1.5 Nm 3 /h and thread at 3 bar air pressure. At these speeds, the number of knots is independent from the speed employed. The turbulence effect can be improved if the thread of a bundle of threads is passed over the air borehole as a small ribbon.
It is advantageous to guide the thread ribbon between a horizontally and a two vertically disposed thread guides outside of and before the thread channel. For this purpose, a horizontally disposed ceramic guide can be provided before and after the thread channel at a distance, for example, of 1 cm and two vertically disposed thread guides (combs) at a distance of 3 cm. The distance between the threads should be at least 5 mm to avoid an entanglement of the wet threads. Therefore, such a bundle of threads must be subdivided into several partial bundles during the treating in the turbulent air stream. For example, it is advantageous to subdivide a bundle consisting of 8 threads into 4 partial bundles consisting of 2 threads/cm=5 mm distance. A relatively coarse titer with e.g. dtex 167 f 30 having a relatively small air borehole of appr. 0.8 mm, as compared to known nozzle boreholes for the same titer, is already sufficient for the turbulence device in accordance with the invention; this also accounts for the low consumption of compressed air.
It is advantageous to redirect the thread before and after the thread channel by 5 to 20 degrees via a horizontal thread guide. The angle results from the configuration of the nozzle bars. It is not possible to have the same angles at all the places where turbulence is performed. At the same time it must be ensured that sufficient distance is provided from the vertical thread guides (combs) to the horizontal thread guides and that the redirection at the vertical thread guide is not too great. The vertical thread guides must not approach the horizontal guides; this prevents the thread from lying flatly.
In order to avoid a dilution of the sizing liquor, the water coming from the stretching trough must be completely removed. The drainage of the surface water requires an amount of air along the thread of at least 0.1 Nm 2 /h per mm 2 of thread channel cross section. The remaining moisture of polyester is at less than 1%, and for polyamide under 10%. Falling below this air speed results in incomplete blowing off of the water and in a significant turbulence decrease.
The simultaneous insertion of a multitude of threads into the thread channels of the nozzle body, which is possible through the removable covers of the nozzle bodies, has the advantage that a partial bundle of threads can be inserted as a whole by means of an adhesive tape without separate insertion into the individual nozzles. The partial threads are thus recombined in the original thread density. An enormous saving of working time is another obvious advantage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 perspective view of a device with eight nozzle bars for intermingling a bundles of threads in turbulent air stream.
FIG. 1a an enlargement of a nozzle bar with a nozzle body, a cover and thread guide
FIG. 2 perspective view of a location of turbulence with the cover lifted
FIG. 3 cross section view of the nozzle body
FIG. 4 overhead view of the nozzle body
FIG. 5 a longitudinal section view of a thread channel in the turbulence area according to A--A of FIG. 3
FIG. 6 a cross section of an enlarged thread channel in the turbulence area
FIG. 7 overhead view of a variant of a thread channel with the cover open.
At the end of the specification is a table providing the measured results for a thread manufactured with a turbulence nozzle according to the invention as compared to a known nozzle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows diagrammatically a perspective view of a device for intermingling a bundle of threads in a turbulent air stream in accordance with the invention. The examples are four nozzles bars 1, 1', 1", 1'" each disposed symmetrically on both sides of the support 2 in a vertically and stepwise offset arrangement. Each nozzle bar 1 contains an air passage as a supply for the turbulence body and the thread guides. Support 2 contains in addition the compressed air supply. A wet bundle of threads (50% water cover) coming from a water-containing stretching trough, which is not represented, is in its width subdivided into two parts in order to avoid contact with support 2. In the height, the bundle is subdivided in many partial bundles, of which partial bundles 3 and 3' are represented. Depending on its length, each nozzle bar 1, in turn, is supplied with a number of nozzle bodies 6; the example represents on nozzle bar 1 the nozzle bodies 6 and 6' and on nozzle bar 1'" the nozzle bodies 61 and 61'. After passing through nozzle bars 1, 1', 1" or 1'" the now dry bundles of thread, top bundle 4' and bottom bundle 4 of which are represented, are reunited and fed to a sizing bath which is not represented.
A E F G C H refer to the limitation of the top partial bundle of threads of one half of the support frame and A E J K C H designate the bottom partial bundle of threads. A E F G=3'; A E J K=3; J K C H=4; F G C H=4'.
Since the water is blown off of the incoming thread bundles 3 in the thread channels 7, the nozzles bars have a wet side at the thread inlet and a dry side at the thread outlet. Therefore, the nozzle bars 2 are offset stepwise so as to permit the water only to drop on the wet threads.
FIG. 1a represents a nozzle body 6 as it is disposed on nozzle bar 1. Conventionally, a nozzle body 6 is provided with ten to twenty thread channels 7 which are covered by cover 8.
Vertically disposed thread guides 9 and horizontally disposed thread guides 10 are disposed on nozzle bar 1. Each nozzle bar 6 is supplied with a partial bundle of threads 31, of which ten to twenty wet filament threads pass through each thread channel 7, which they exit as dry filament threads 41 treated in a turbulent air stream.
FIG. 2 represents a perspective view of a thread channel 7 in a nozzle body with cover 8 lifted. The bottom part of channel 7 is configured as a groove which is provided with a centered borehole 12 for compressed air. An air checking borehole 8' is disposed in the cover contact surface of nozzle body 6; it is closed if cover 8 fits correctly and serves as a means for monitoring cover closure. A wet thread 3 is fed to channel 7 via a vertical thread guide 9 and a horizontal thread guide 10; it exits channel 7 as a dry thread 4 via a horizontal thread guide 10' and a vertical thread guide 9' and is introduced into a sizing bath. For a redirection by an angle α, the thread 3 is put flat at thread guide 10, thus creating a ribbon which increases the turbulence. In order to avoid problems when the thread is put flat, there must be a sufficient distance between the thread guide 9 and thread guide 10, for example about 2 cm, and the redirection at thread guide 9 should be relatively small.
FIG. 3 represents a section view of nozzle body 1 provided with a multitude of thread channels 7 with the respective boreholes 12; the cover 8 is closed in this representation. The threads 3, 4 run approximately in the center of thread channel 7.
An overhead view according to FIG. 4 demonstrates, while the cover is open, several thread channels 7 of the nozzle body 1 with boreholes 12 for air supply. The distances between the individual thread channels amount to a multiple of the distances between the incoming and outgoing bundle of threads.
FIG. 5 is a longitudinal section view of thread channel 7 of nozzle body 1 during operation with the cover closed. After passing borehole 12, the partial bundle of threads 3, supplied with compressed air of 1 to 4 bar, becomes partial bundle of threads 4, treated in a turbulent air stream.
FIG. 6 provides the dimensions of thread channel 7 in optimal configuration according to the invention. It is obvious that section 11 represents a semicircle with radius r; the diameter and the height of thread channel 7 correspond to twice the radius r of semicircular section 11; the top represents a rectangle 16 with the height r and the width 2r.
FIG. 7 is a variant of thread channel 7 including the actual turbulence channel 15 in the center and a front inlet part 13 for partial bundle of threads 3 before turbulence and an outlet part 14 for partial bundle of threads 4 after turbulence which is performed by means of compressed air coming from a borehole 12 of a compressed air supply which is not represented. The high air speed blows off the water along the thread at 13. The length of the turbulence part 15 is about three times its diameter.
During operation, a comb (not shown) serves, for feeding purposes according to FIG. 1, to separate a bundle of threads in its width AB into individual partial bundles of threads. The partial bundles of threads 3 to 3' are separated in order with an adhesive tape and thus inserted into the open nozzle body 6 and on width AB of a not represented comb. In the area CD, the partial bundles of threads 4 to 4' after undergoing turbulence are recombined, for example, to 8 threads per cm.
The turbulence is determined by the diameter of turbulence chamber 15; large diameters produce strong knots of air in large, irregular distances and small diameters smaller knots of air in smaller, regular distances. A small diameter of inlet part 13 and outlet part 14 causes high air speeds along the moving partial bundle of threads 3, 4 and results in good water drainage. The nozzles in accordance with the invention permit to obtain, despite the wet threads, a turbulence with long, strong knots of air.
The table following the specification provides the measuring results of a thread manufactured with a turbulence nozzle in accordance with the invention as compared to one of the known nozzles. For all examples the thread tension was at 0.05 cN/dtex.
The device in accordance with the invention combines the following advantages:
simple insertion of a thread into the open nozzle bodies;
the thread spacing in a partial bundle of threads corresponds to a whole number multiple of the number of threads incoming and outgoing, so that the partial bundles of threads can be separated by an adhesive, inserted as a bundle, and recombined to form a complete bundle at the exit
low air consumption;
no serimetry damages;
complete blowing off of surface water;
no efficiency decrease caused by water;
sufficient turbulence intensity even for more coarse titers;
The device in accordance with the invention is particularly suited for the intermingling of a bundle of threads consisting of wet, smooth, synthetic filament threads in a turbulent air stream when stretch sizing is employed and the turbulence takes place between two operational steps. The treating in a turbulent air stream as described can even be performed in the warping department, which permits using non-treated threads in the warping department. With the turbulence nozzles in accordance with the invention, the turbulence effect loss is smaller than if running via travellers, cops, thread brake, railing and so forth.
__________________________________________________________________________ Polyester (Polyethylene Polyamide terephthalat) (Nylon) 167 f 30 78 f 23Titer dtex invention prior art invention prior art__________________________________________________________________________speed m/min 200 143 200 171air pressure bar 3.5 3.8 3.0 3.0nozzle borehole mm 0.8 1.2 0.8 1.2air consumption Nm.sup.3 /h 1.3 3.14 1.2 2.6per nozzle Nm.sup.3 /kg 6.5 20.4 12.6 28.5turbulence Kn/m.sup.(1) 15 13.2 30 24titer after dtex.sup.(2) 167 180 77 86turbulence cN/tex.sup.(2) 43 32 49 35.5strengthbreaking %.sup.(2) 28 27.3 38 34elongation__________________________________________________________________________ .sup.(1) measured according to the needle test method .sup.(2) The same breaking elongation was aimed for in all tests. Due to serimetry damages at the known nozzle, the stretching was corrected correspondingly. The result is a titer slightly too high and a strength which is slightly too low.
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Device for drying a bundle of threads between a stretching trough and a sizing trough has a tiered array of elongate nozzle bodies each having a plurality of thread channels therein for receiving a partial bundle of threads therethrough. Each channel has a cross section consisting of a semicircular bottom part of radius r and a rectangular top part of width 2r and height r, the semicircular bottom part having a centered air inlet for generating turbulence to dry the threads. The channels are closed by a metal cover which is received flushly against a cover contact surface having an air checking borehole which assures that the cover is in place. A preferred embodiment has channels with restricted inlet and outlet parts to facilitate generating knots of turbulent air in a central turbulent part of the channel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a multi-legged walking apparatus for a robot.
2. Description of the Prior Art:
Moving mechanisms developed for autonomous mobile robots include wheel systems, crawler systems, and leg systems. Multi-legged walking robots have been developed having two, three, four or six legs. A multi-legged walking apparatus having three or more legs walks by placing three or more legs on the ground to support the weight of the apparatus and swinging the other leg to another point on the ground. This alternating changeover from support leg to swing leg enables the weight of the apparatus to be supported as the apparatus moves in a walking motion. This walking by alternating changeover between support and swing legs is a relatively static motion.
Dynamic walking machines are also being developed in which a dynamic walking motion is achieved by utilizing movement resulting from swinging a leg forward. The multiple legs on such an apparatus have to have two functions: a support function to support the weight of the apparatus, and a forward thrust function by thrusting against the ground.
FIG. 9 shows a conventional multi-legged dynamic walking apparatus 51. In this apparatus, two front legs 53 and two back legs 54 are each attached to a frame 52 via a hip joint 56. Each of the legs 53 and 54 has a knee joint 55. The knee joints 55 all have the same structure, and allow the legs 53 and 54 to bend and straighten. The hip joints 56 and knee joints 55 are each provided with actuators arranged to support the weight of the apparatus and provide forward thrust. As the apparatus's center of gravity 21 is substantially at the center of the apparatus, the weight of the apparatus acts on all of the legs 53 and 54. This means that even when the apparatus is not in motion, the knee and hip drive actuators have to be in constant operation to enable the weight of the apparatus to be supported by the knee joints, and powerful actuators have to be used if the apparatus is a heavy one. When walking, horizontal forward thrust has to be generated while the apparatus is being supported by the legs, and this also has to be effected by using powerful knee and hip actuators. This means an increase in the weight of the actuators themselves.
An object of the present invention is to provide an efficient multi-legged walking apparatus in which optimum disassociation between the apparatus weight support function and the forward thrust function of legs is provided by allocating support functions to front legs and forward thrust functions to back legs, which reduces the amount of energy used by the apparatus and enables the size of the apparatus to be reduced, the number of actuators used to be decreased, and the maximum vehicle speed to be increased.
SUMMARY OF THE INVENTION
For attaining this object, the present invention provides a multi-legged walking apparatus comprising a first plurality of legs having a large weight support capacity and a second plurality of legs having a large thrust force, in which the first plurality of legs has a smaller thrust force than the thrust force of the second plurality of legs and the second plurality of legs has a smaller weight support capacity than the weight support capacity of the first plurality of legs, overall apparatus weight is supported substantially by the first plurality of legs and overall apparatus thrust is provided substantially by the second plurality of legs.
In accordance with this invention, there is a separation between the weight support function and thrust function required of the legs, with the weight of the apparatus being supported mainly by the front legs, and the thrust being provided by the back legs minimally affected by the overall weight of the apparatus. With this configuration, front leg knee actuators only need to be structurally capable of supporting the weight of the apparatus, and need virtually no ability to deliver forward thrust. As a result, those actuators can be low-output types having a simple structure. On the other hand, the joint actuators of back legs need virtually no apparatus weight support capability, and instead only need to be able to generate forward thrust by thrusting against the ground, so those actuators, too, can be low-output types having a simple construction.
Compared to conventional multi-legged walking apparatuses in which each leg had to deliver thrust while supporting the apparatus, the multi-legged walking apparatus of this invention uses energy more efficiently. In addition, since the invention uses fewer actuators, and the actuators it does use are smaller than those of a conventional apparatus, the actuators are lighter, so the overall apparatus is lighter, thereby enabling energy consumption to be reduced.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an embodiment of the multi-legged walking apparatus of this invention;
FIG. 2 is a plan view of the apparatus of FIG. 1;
FIG. 3 is a side view of the apparatus of FIG. 1;
FIG. 4 is a side view of the apparatus of FIG. 1, showing the changeover period from support leg and thrust leg to swing leg;
FIG. 5 illustrates the load distribution between the front and back legs of the apparatus of FIG. 1, when a front leg is swung to the front;
FIG. 6 illustrates the load distribution between the front and back legs of the apparatus of FIG. 1, when a front leg is swung to the back;
FIG. 7 is a plan view of a multi-legged walking apparatus according to another embodiment of the invention;
FIG. 8 is a side view of the apparatus of FIG. 7; and
FIG. 9 is a perspective view showing the arrangement of a conventional multi-legged walking apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the multi-legged walking apparatus according to this invention will now be described with reference to FIGS. 1 to 3, which illustrate a multi-legged walking apparatus 1. The apparatus 1 has a frame 2. The frame 2 has two front legs 3a and 3b and two back legs 4a and 4b. The front legs 3a and 3b and back legs 4a and 4b are attached to the frame 2 by hip joints 11 and 17, respectively. The front legs 3a and 3b are each comprised of a rigid, rod-shaped upper link 5a, a rigid, rod-shaped lower link 5b, and a knee joint 6 that connects the links rotatably. The lower end of the lower link 5b has a ground contact member 7. The knee joint 6 is a rotary joint and is provided with a rotary actuator 8 with a brake to control the position of the knee joint 6. A hip joint 11 at the upper end of each of the front legs 3a and 3b has a rotary actuator 12 to control the position of the hip joint 11. The back legs 4a and 4b are each comprised of a rigid, rod-shaped upper link 13a, a rigid, rod-shaped lower link 13b, and a knee joint 14 that connects the links rotatably. The lower end of the lower link 13b has a ground contact member 7. The knee joint 14 is provided with a rotary actuator 16 to control the position of the knee joint 14. The hip joint 17 at the upper end of each of the back legs 4a and 4b has a rotary actuator 18 to control the position of the hip joint 17.
An important element of this walking apparatus is that its center of gravity 21 is positioned between and just or nearly just over the front legs 3a and 3b. When design or component device layout considerations make it impossible to locate the center of gravity 21 between and above the front legs 3a and 3b, the apparatus is configured by equipping the frame 2 with an extension portion 22 to which a counterbalance 23 is attached so that the addition of the weight of the counterbalance 23 results in the center of gravity 21 being located between and above the front legs 3a and 3b. Instead of the counterbalance 23, a work manipulator or the like can be used that has an equivalent mass. By adjusting the position of the balance-weight, the counterbalance can also be used to change the position of the center of gravity 21, as required. More specifically, when the walking apparatus is to be used to perform some task on uneven terrain, the apparatus can be put on hold and the position of the balance-weight adjusted to shift the center of gravity 21 to the center of the four legs to make the apparatus stable. Or, for optimum walking efficiency, the center of gravity 21 can be moved toward the front legs to increase the leg function share ratio. Were the center of gravity 21 to be moved fully forward to over the front legs, the back legs could be considered as constituting a manipulator to which a two-legged walking apparatus is attached, in which case the back legs could be used as a manipulator by suitably modifying the ends of the back legs.
With the apparatus 1 thus constituted, walking is effected by cooperative operation of the front legs 3a and 3b and back legs 4a and 4b. This is achieved by controlling the rotary actuators 8, 12, 16 and 18 of the knee joints 6 and 14 and hip joints 11 and 17. In the walking motion, the front legs 3a and 3b switch between support leg function and swing leg function, substantially supporting the weight of the apparatus 1 when in the support leg phase. The back legs 4a and 4b thrust the apparatus 1 forward by thrusting against the ground 24.
This will now be described more specifically with reference to FIGS. 2, 3 and 4. When the right front leg 3b is a support leg, as shown in FIG. 3, the knee joint 6 is locked by the brake mechanism, more or less forming upper link 5a and lower link 5b into a single rigid body supporting the weight of the apparatus 1. At this time, the rotary actuator 8 of the knee joint 6 is braked and not in operation. Thus, the front leg 3b is given a weight support function that allows the multi-legged walking apparatus to be supported without expending energy. The rotary actuator 8 is activated to raise the ground contact member 7 of the left front leg 3a, which is the swing leg, from the ground 24 with the knee joint 6 slightly bent, in which state the rotary actuator 12 of the hip joint 11 is activated to advance the leg forward. In the next operation the left front leg 3a becomes a support leg, links 5a and 5b are locked by the brake of rotary actuator 8 to form a single rigid leg, supporting the apparatus, while at the same time the right front leg 3b becomes the swing leg, lifting off the ground (FIG. 4).
When the right back leg 4a is the thrust leg, with its ground contact member 15 in contact with the ground the rotary actuators 16 and 18 of the knee joint 14 and hip joint 17 are activated to push the right back leg 4a against the ground 24, thereby imparting a forward thrust force to the apparatus 1 (FIG. 3). At this time, with the left back leg 4b becoming the swing leg, the ground contact member 15 rises from the ground 24 and the left back leg 4b is moved forward by activating the rotary actuators 16 and 18 of the knee joint 14 and hip joint 17. In the next operation the left back leg 4b moved forward is placed on the ground and changes to a thrust leg (FIG. 4). Walking is effected by repeating these actions. Since there is almost no weight acting on the back legs 4a and 4b, the knee joints 14 do not require the actuators to support the apparatus 1. Similarly, the actuators for weight support purposes or for generating a thrust force are not required on the front legs.
In the multi-legged walking apparatus 1 described above the center of gravity 21 is located above the space between the front legs 3a and 3b. However, when the legs along a mutually diagonal line are in a trot gait, with one pair of legs planted and the other pair of legs swinging, when viewed from the front, both the legs are in contact with the ground, but when the apparatus tilts toward the front leg that forms the swing leg, the front leg that is the swing leg changes to a support leg before the apparatus falls over, enabling the apparatus to keep on walking and not fall down. This operation can be effected with increased smoothness by the use of actuators for moving the center of gravity toward the support leg side when the apparatus tilts. For a pace gait in which both the back and front legs on the right side are raised at the same time while the back and front legs on the left side are both planted on the ground, since the apparatus is inclined toward the swing leg side, changeover between the support leg and the swing leg is required before the apparatus falls over; otherwise the center of gravity has to be constantly maintained over the front leg that becomes the support leg. Furthermore, in the apparatus according to the present invention, when a large thrust force is given to the two back legs to be thrust upwardly aslant, with the two front legs planted on the ground, the front legs are moved upward aslant and lift off the ground along with the apparatus in consequence of kicking the ground and immediately thereafter, when the front legs are made straightforward, the front legs and then the back legs will land on the ground. Thus, the present invention can attain a gallop gait in which both the front legs and the back legs lift off the ground at the same time.
A certain degree of frictional force is needed between leg end ground in order to obtain forward thrust by the back legs. This frictional force can be obtained as follows. When the apparatus 1 is being thrust forward in a walking motion and the front leg 3a is planted to the front, as shown in FIG. 5, the load component of the front leg 3a acts at a downward angle to the back, as indicated by arrow 26, so the load component of the back leg 4a also acts at a downward angle to the back, as shown by arrow 27. This load component 27 can be divided into a horizontal load component 29 and a perpendicular load component 28. Part of the load component acting on the back leg 4a results in a frictional force between the back leg and the ground. Reference numeral 25 indicates the direction of gravitational force.
When the front leg 3a is planted to the back, as shown in FIG. 6, the load component of the front leg 3a acts at a forward downward angle shown by arrow 26, so the load component of the back leg 4a also acts at a forward downward angle shown by arrow 27. The load component 27 can be divided into a horizontal load component 29 and a perpendicular load component 28 that results in a frictional force between the back leg and the ground. The frictional force can be reduced to the minimum needed by adjusting the overall center of gravity in the vicinity of the front legs or by dynamically adjusting the counterbalance during walking motion.
FIGS. 7 and 8 show another embodiment of the multi-legged walking apparatus of the invention. In this embodiment, the knee joints 6 of the front legs 3a and 3b are linear joints instead of rotary, and are driven by linear actuators 8. When front leg 3a or 3b changes to a swing leg, the leg is shortened by retracting the upper part of the lower link 5b into the knee joint 6, thereby bringing the ground contact member 7 off the ground to allow the leg to be swung. When front leg 3a or 3b changes to a support leg, the lower link 5b is extended back down from the knee joint 6 and locked, so the leg becomes rigid. The linear joint used may be constituted by a ball-and-screw mechanism, as one example. Since the linear movement is only effected by rotation of the ball-and-screw, a heavy weight can be constantly supported without locking the joint. In addition, rotating the ball-and-screw enables linear motion to be readily effected while the heavy weight is still being supported. The gear ratio (the amount of linear motion per rotation) can readily be set by cutting the thread at an appropriate pitch. With the thread formed on the upper part of the lower link 5b, the leg is extended or shortened by using a motor or the like to rotate the lower link 5b. When the motor is stopped, the links form a rigid bar. When extended, the leg supports the apparatus; when retracted, it becomes a swing leg. As in the first embodiment, back legs 4a and 4b have rotary actuators 16 to control the positions of the knee joints 14.
As described in the foregoing, in the multi-legged walking apparatus 1 according to this invention, the weight of the apparatus 1 is supported mainly by the front legs by positioning the weight and center of gravity of the apparatus above the front legs. When the front legs function as support legs the knees are locked, so no energy is expended. That is, the front legs only need actuators for controlling the knee joints, and do not need actuators for weight support functions. In a multi-legged walking apparatus almost none of the weight is on the back legs, so the back legs do not require apparatus weight support actuators either. Thus, actuators are only required for thrust purposes.
Although the invention has been described with reference to a four-legged walking apparatus, the invention is not limited to a four-legged configuration, being also applicable to a six-legged configuration. Such a six-legged apparatus would have four front legs and be configured so that the center of gravity of the apparatus is at the center of the four legs and thrust is provided by the remaining two back legs.
Thus, the multi-legged walking apparatus according to this invention does not need actuators to support the weight of the apparatus. As such, fewer actuators are required, and those that are required only need to be low-output types. As a result, the apparatus uses less energy and is economical to manufacture and operate.
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A multi-legged walking apparatus includes a first plurality of legs having a large weight support capacity and a second plurality of legs providing a large thrust force. The first plurality of legs provide a smaller thrust force than the thrust force of the second plurality of legs, and the second plurality of legs have a smaller weight support capacity than the weight support capacity of the first plurality of legs. The overall weight of the apparatus is supported substantially by the first plurality of legs, and the overall thrust of the apparatus is provided substantially by the second plurality of legs.
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RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/070,934, filed on Jan. 9, 1998, entitled “Synthesis of Trans-N,N-Dimethyl[3-(3′,4′-Dichlorophenyl) Indan-1-yl] Ammonium Hydrogen Maleate,” the entire teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Biogenic amines derived from the amino acid tyrosine (dopamine, norepinephrine, and epinephrine) and tryptophan (serotonin) are neurotransmitters that have been shown to be involved in disorders such as psychosis, depression, and Parkinson's disease. Chemicals that modulate the activity of one or more of these neurotransmitters can be used to treat the symptoms of these disorders. Trans-3-aryl-1-indanamines have been shown to be potent inhibitors of dopamine, norepinephrine and epinephrine uptake, while cis-3-aryl-1-indanamines have been shown to selectively inhibit the uptake of serotonin (Bogeso, et al, J. Med. Chem., (1985), 28:1817).
Current synthetic routes to 3-aryl-1-indanamines produce a mixture of the regioisomers which must be separated. These methods typically are costly and time consuming.
SUMMARY OF THE INVENTION
The present invention is a method of preparing a 3-aryl-1-indanamine sented by structural formula I:
and physiologically acceptable salts thereof.
In structural formula I, phenyl ring A can be unsubstituted or substituted with 1-4 substitutents.
R 1 is an aromatic group which can be substituted or unsubstituted.
R 2 and R 3 are each, independently, hydrogen, an aliphantic group, a substituted aliphatic group, an aromatic group, a substituted aromatic group, an aralkyl group, or a substituted aralkyl group. Alternatively, R 2 and R 3 , taken together with the nitrogen substitutent on the indan ring, form a non-aromatic ring system having 1-2 heteroatoms such as nitrogen, oxygen or sulfur.
The method of preparing a 3-aryl-1-indanamine represented by structural formula I comprises a first step of reacting, in the presence of a Friedel-Crafts catalyst and a proton source, a substituted or unsubstituted benzene, having at least two consecutive unsubstituted aromatic carbons, with a 3-aryl-1-prop-2-enoic acid to form a 3-aryl-3-phenyl-1-propanoic acid. 3-Aryl-1-prop-2-enoic acid and 3-aryl-3-phenyl-1-propanoic acid can be represented by structural formulas II and III, respectively:
The method further comprises a second step in which the 3-aryl-3-phenyl-1-propanoic acid (III) formed in step 1 is treated with a second Friedel-Crafts catalyst to form a 3-arylindan-1 -one represented by structural formula IV:
The method further comprises a third step in which the 3-arylindan-1-one (IV) formed in step 2 is reacted with a reducing agent to form a 3-arylindan-1-o1 represented by structural formula V:
The method further comprises a fourth step in which the 3-arylindan-1-o1(V) formed in step 3 is reacted with an activating agent in the presence of a base to form an activated 3-arylindan-1-o1.
The method further comprises a fifth step in which the activated 3-arylindan-1-o1 formed in step 4 is reacted with an amine compound represented by structural formula VI:
to form a 3-aryl-1-indanamine.
Another embodiment of the present invention is a method of forming a 3-phenyl-1-indanamine represented by structural formula VII:
and physiologically acceptable salts thereof
Rings A and B are each, independently, substituted or unsubstituted. Ring A can be unsubstituted or can have 1-4 substitutents, and ring B can be unsubstituted or can have 1-5 substitutents.
R 2 and R 3 are defined as above.
The method of preparing a 3-phenyl-1-indanamine represented by structural formula VII comprises a first step of reacting, in the presence of sulfuric acid, a substituted or unsubstituted benzene, having at least two consecutive unsubstituted aromatic carbons, with a 3-phenyl-1-prop-2-enoic acid to form a 3,3-diphenyl-1-propanoic acid. 3-Phenyl-l-prop-2-enoic acid and 3,3-diphenyl-1-propanoic acid can be represented by structural formulas VIII and IX, respectively:
The method further comprises a second step of treating the 3,3-diphenyl-1-propanoic acid (IX) formed in step 1 with chlorosulfonic acid to form a 3-phenylindan-1-one represented by structural formula X:
The method further comprises a third step of reacting the 3-phenylindan-1-one (X) formed in step 2 with sodium borohydride to form a 3-phenylindan-1-o1 represented by structural formula XI:
The method further comprises a fourth step in which the 3-phenylindan-1-o1 (XI) formed in step 3 is reacted with an aliphatic or aromatic sulfonyl chloride in the presence of a base to form a 3-phenylindan-1-sulfonate ester represented by structural formula XII:
wherein R 4 is a substituted or unsubstituted aliphatic or aromatic group.
The method further comprises a fifth step in which the 3-phenylindan-1-sulfonate ester (XII) formed in step 4 is reacted with an amine compound represented by structural formula VI to form the 3-phenyl-1-indanamine (VII).
Another embodiment of the present invention is a method of preparing a 3-phenyl indan-1 -one represented by structural formula X. The method comprises a first step of reacting, in the presence of a first Friedel-Crafts catalyst and a proton source, a compound represented by structural formula VIII with a substituted or unsubstituted benzene having at least two consecutive unsubstituted aromatic carbons to form a 3,3-diphenyl-1-propanoic acid (IX), and a second step in which the 3,3-diphenyl-1-propanoic acid (IX) is converted to a 3-phenylindan-1-one (X) by treatment with a second Friedel-Crafts catalyst.
Another embodiment of the present invention is a method of preparing a 3-phenyl indan-1-o1 represented by structural formula XI. The method comprises three reaction steps. In the first step, a compound represented by structural formula VIII is reacted, in the presence of a first Friedel-Crafts catalyst and a proton source, with a substituted or unsubstituted benzene having at least two consecutive unsubstituted aromatic carbons to form a 3,3-diphenyl-1-propanoic acid (IX). In the second step, the 3,3-diphenyl-1-propanoic acid (IX) is converted to a 3-phenylindan-1-one (X) by treatment with a second Friedel-Crafts catalyst. In the third step, the 3-phenyl indan-1-one (X) is reacted with a reducing agent to form a 3-phenylindan-1-o1 (XI).
Another embodiment of the present invention is a method of preparing a 3-phenylindan-1-one represented by structural formula X. The method comprises the step of treating a 3,3-diphenyl-1-propanoic acid (IX) with a Friedel-Crafts catalyst.
Another embodiment of the present invention is a method of preparing a 3-phenyl-1-indanamine represented by structural formula VII. The method comprises a first step in which a 3-phenylindan-1-o1 (XI) is reacted with an activating agent in the presence of a base to form an activated 3-phenyl-1-indanamine, and a second step in which the activated 3-phenyl-1-indanamine is reacted with an amine compound represented by structural formula VI to form the 3-phenyl 1-indanamine (VII).
3-Aryl-1 -indanamines are potent inhibitors of dopamine, norepinephrine, epinephrine and serotonin uptake, and therefore, expected to be useful in treating disorders such as psychosis, depression and Parkinson'disease. The method described herein allows 3-aryl-1-indanamines to be synthesized in high yields with fewer reaction steps than previously described methods. In addition, trans-3-aryl-1-indanamines can be selectively prepared by the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The features and other details of the method on the invention will now be more particularly described and pointed out in the claims. It will be understood that the particular embodiments of the invention are shown by way of illustration and not as limitations of the invention. The principle features of this invention can be employed in various embodiments without departing from the scope of the invention. All parts and percentages are by weight unless otherwise specified.
A schematic representation of the method of preparing a 3-aryl-1-indanamine can be seen in Scheme I. The first step is a Friedel-Crafts alkylation in which a benzene adds to a double bond. Dialkylation is minimized by using excess benzene. A proton source is necessary for the reaction, therefore protonic Friedel-Crafts catalysts are preferred. A proton source is a compound that has acidic protons, such as organic or inorganic acids.
The second step is a Friedel-Crafts acylation to close the five membered ring. This reaction can proceed by converting the carboxylic acid into an acid chloride followed by treatment with a Lewis acid, or the carboxylic acid can be added directly to ring A by treatment with a protonic Friedel-Crafts catalyst.
A Friedel-Crafts catalyst can be a Lewis acid (i.e., and electron acceptor) or a protonic acid (i.e., a proton donor). Protonic acids are preferred for the Friedel-Crafts alkylation of step 1. Examples of protonic acid catalysts include inorganic acids such as anhydrous sulfuric acid or hydrogen fluoride. Examples of Lewis acids that can catalyze Friedel-Crafts alkylations and acylations include A1Br 3 , A1C1 3 , GaC1 3 , FeC1 3 , SbC1 5 , ZrC1 4 , SnC1 4 , BC1 3 , BF 3 , SbC1 3 .
In the third reaction step, the ketone is reacted with a reducing agent to form an alcohol. A reducing agent, as used herein, is a chemical or combination of chemicals that will convert the ketone to an alcohol. Suitable reducing agents include sodium borohydride, lithium borohydride, borane, disiamylborane, 9-bora-bicyclo[3.3.1]nonane, lithium tri-tert-butoxyaluminohydride aluminum hydride, lithium triethylborohydride, and lithium tri(sec-butyl)borohydride. Preferred reducing agents selectively convert the 3-arylindan-1-one into a cis-3-arylindan-1-o1. Sodium borohydride is a preferred reducing agent.
Other reducing agents suitable for preferentially forming either cis or trans 3-arylindan-1-o1 include combinations of a carbonyl reducing agent, such as lithium aluminum hydride, lithium borohydride or sodium borohydride, with an optically pure compound, such as an amino alcohol, sugar or hydroxyalkaloid. Typically, a chiral reducing agent is about 25% to about 75% (w/w) carbonyl reducing agent and about 25% to about 75% (w/w) optically active compound. Other suitable reducing agents suitable for preferentially forming either a cis or trans 3-arylindan-1-o1 include 2,5-dimethylborolane, as described in Imai et al., J. Am. Chem. Soc., 108:7402 (1986), K-glucoride, as described in Brown et al., J. Org. Chem., 53:1231 (1988), NB-Enantride, as described in Midland et al., J. Org. Chem., 56:1068 (1991), borane with a chiral oxazaborolidine catalyst, as described in Corey et al., J. Am. Chem. Soc., 109:7925 (1987), and R-Alpine-Hydride and S-Alpine-Hydride, obtainable from Aldrich Chemical Co.
Alternatively, preferential formation of a cis or trans 3-arylindan-1-o1 can occur through the use of a sterically large (or bulky) carbonyl agent.
In the fourth step, the 3-arylindan-1-o1 is reacted with an activating agent. An activating agent, as used herein, is a compound that can react with an alcohol in the presence of a base to convert the alcohol into a good leaving group. Suitable activating agents include thionyl chloride or substituted or unsubstituted aliphatic or aromatic sulfonyl chlorides, for example, trifluoromethanesulfonyl chloride. Suitable bases include hindered organic bases such as trialkyl amines. Preferred activating groups can react with the 3-arylindan-1-o1 such that it retains its chiral configuration at the C-1 position. A particularly preferred activating agent and base combination is a substituted or unsubstituted aliphatic or aromatic sulfonyl chloride and a trialkyl amine.
In the fifth step, an amine compound is reacted with the activated 3-arylindan-l-o1. An amine compound, as used herein, is ammonia or a compound that has a primary or secondary amine. The amine can be part of a ring system. For example, piperazine, pyrrolidine, piperidine, morpholine and piperidinopiperidine. Amine compounds that react with the activated 3-arylindan-1-o1 and invert the chiral configuration at the C-1 position are preferred. For example, an amine compound that reacts with an activated cis-3-arylindan-1-o1 to form a trans-3-aryl-1-indanamine is preferred. Piperazines are particularly preferred amine compounds.
The 3-aryl-1-indanamine is obtained as the free base which can be converted to a salt by recrystalization with an acid such as maleic acid. Physiologically acceptable salts are preferred. An enantiomerically pure chiral acid, such as L-(+) or D-(−) tartaric acid, can be used to resolve the (1S, 3R) and (1R, 3S) enantiomers of 3-aryl-1-indanamine by selective recrystalization of the salt. The salt can be converted back to the free base by treating with a basic solution, such as an aqueous sodium bicarbonate solution, followed by extraction of the enantiomerically pure 3-aryl-1-indanamine with an organic solvent.
Aliphatic groups, as used herein, include straight chained or branched C 1 -C 18 hydrocarbons which are completely saturated or which contain one or more units of unsaturation, or cyclic C 3 -C 18 hydrocarbons which are completely saturated or which contain one or more unconjugated double bonds. Lower alkyl groups are straight chained or branched C 1 -C 6 hydrocarbons or C 3 -C 6 cyclic hydrocarbons which are completely saturated.
Aromatic groups include carbocyclic ring systems (e.g. benzyl) and fused polycyclic, carbocyclic ring systems (e.g. naphthyl, anthracenyl or 1,2,3,4-tetrahydronaphthyl). In addition, aromatic groups include heteroaryl ring systems (e.g., thiophene, furan, pyrroles, or pyrans) and heteroaryl ring systems in which a carbocyclic aromatic ring, a carbocyclic non-aromatic ring or heteroaryl ring is fused to one or more other heteroaryl rings. For example, benzimidazole, thianaphthene, benzofuran, or indole. An aryl group is a carbocyclic aromatic ring system or a polycyclic, carbocyclic aromatic ring system.
An aralkyl group is an aromatic substituent that is linked to a compound by an aliphatic group having from one to four carbon atoms.
Suitable substitutents include aliphatic groups, halogenated aliphatic groups, aromatic groups, aralkyl groups, halogens, trihalomethyl, cyano, and nitro. Other suitable substitutents include R 6 O—, R 6 OC(O)—, R 6 C(O)—, R 6 C(O)O—, R 6 S—, R 6 S(O)—, R 6 S(O) 2 —, R 6 S(O) 2 O—, R6R 7 N—, R 6 R 7 NC(O)—, R 6 HNC(O)NH—, or R 6 C(O)NH—, wherein R 6 and R 7 are each, independently, hydrogen, a lower alkyl group, an aryl group and and aralkyl group.
In a preferred embodiment, ring A is substituted with one to four activating substituents. An activating substituent is a substituent that is an electron donor, and therefore, increases the electron density of the aromatic ring. Examples of activating substitutents include aliphatic groups, aromatic groups, aralkyl groups, R 6 O—, and R 6 S—.
In another preferred embodiment, the aromatic group represented by R 1 is substituted with a deactivating substitutent. A deactivating substitutent is an electron withdrawing substituent. Electron withdrawing substitutents decrease the electron density of the aromatic ring. Examples of deactivating substitutents include halogens, trihalomethyl, cyano, nitro, R 6 OC(O)—, R 6 C(O)—, R 6 S(O)—, R 6 S(O) 2 — and R 6 R 7 NC(O)—.
In another preferred embodiment, ring B is substituted with a deactivating substitutent.
EXEMPLIFICATION
EXAMPLE 1
Synthesis of 3-(3′,4′-Dichlorophenyl) 3-Phenylpropanoic Acid
A mixture of 3,4-dichlorocinnamic acid (50 g, 0.23 mole), benzene (150 mL) and concentrated sulfuric acid (100 mL) was stirred (using air driven overhead stirrer) in a 500 mL 3-neck round bottom flask while maintaining a reaction temperature of 85-95° C. The progress of the reaction was followed by HPLC. When the level of 3,4-dichlorocinnamic acid was <1% by HPLC (approximately 24 h), the reaction mixture was cooled to room temperature, then slowly poured into ice (300 g). The mixture was stirred for 30 min. then transferred into a 2 L separatory funnel. The organic layer was separated from the aqueous layer, and the aqueous layer was extracted with ethyl acetate (2×300 mL). The organic layers were combined, washed with water (5×500 mL) and brine (2×400 mL), then concentrated under reduced pressure. Ethyl acetate (500 mL) was added to the concentrate and the solution was evaporated to dryness. The product was dried under high vacuum at room temperature for 24 h. The desired carboxylic acid was obtained as a thick oil (65.8 g, 96% yield).
EXAMPLE 2
Synthesis of 3-(3′,4′-Dichlorophenyl) Indan-1-one
Chlorosulfonic acid (66 mL, 0.99 mole) was added slowly to a stirring solution of 3-(3′,4′-dichlorophenyl) 3-phenylpropanoic acid (65 g, 0.22 mole) in dichloromethane (330 mL) at room temperature. After 30 min., the reaction was monitored by TLC against authentic sample of 3-(3′,4′-dichlorophenyl) 3-phenylpropanoic acid. If the reaction was not complete, an additional 10-20 mL of chlorosulfonic acid was added and the reaction was stirred for an additional 30 min. When the reaction was complete, the mixture was slowly poured into ice (400 g), stirred for 15 min., then transferred to a 1 L separatory funnel. The organic layer was drained and the aqueous layer was extracted with ethyl acetate (2×400 mL). The combined organic layers were washed with water (5×500 mL) and brine (2×400 mL), then concentrated under reduced pressure. A mixture of ethyl acetate:heptane (1:9) (100 mL) was added to the concentrate and the solution was stirred for one hour at room temperature. The temperature was lowered to 5°-10°C. and stirring was continued for 4 hours. The precipitate was recovered by filtration and washed with a cold solution (2×100 mL) of 1:9 ethyl acetate:heptane. The off-white solid was dried under high vacuum for 16 h to obtain 45.6 g (71%) of product. The 3-(3′,4′-dichlorophenyl) indan-1-one was 97% pure by HPLC.
EXAMPLE 3
Synthesis of Cis-3-(3′,4′-Dichlorophenyl)indan-1-o1
A solution of 3-(3′,4′-dichlorophenyl)indan-1-one (25 g, 0.09 mole) in 250 mL of tetrahydrofuran (hereinafter “THF”) was stirred at −5° C. In a separate flask, a solution of sodium borohydride (6.8 g, 0.18 mole) in water (28 mL) was cooled to 0°C., then added dropwise to the solution of 3-(3′,4′-dichlorophenyl)indan-1-one, maintaining the temperature of the reaction mixture between −5-0° C. After addition of the sodium borohydride solution was complete, the cooing bath was removed and the reaction mixture was stirred for 2 h. The reaction was monitored by TLC against an authentic sample of cis-3-(3′,4′-dichlorophenyl)indan-1-o1 and an authentic sample of 3-(3′,4′-dichlorophenyl)indan-1-one. When the starting material disappeared, 150 mL of ice-cold water was added to quench the reaction. After stirring for 1 h, THF was removed under reduced pressure, and the mixture was extracted with ethyl acetate (2×300 mL). The ethyl acetate layer was washed with water (2×250 mL) and brine (2×200 mL), then concentrated under reduced pressure to obtain an oily product. A solution (100 mL) of 1:9 ethyl acetate:heptane was added to the concentrate and stirred for 1 h at room temperature, then at 5°-10° C. for 4 h. The precipitated product was collected by filtration, then washed with an ice-cold solution (120 mL) of 1:9 ethyl acetate:heptane. After drying the solid under high vacuum for 12 h, 18.8 g (74%) of 98.5% pure alcohol was obtained. The product contained ≦1% of the undesired trans-alcohol.
EXAMPLE 4
Synthesis of Trans-1-(N,N-Dimethylamino) 3-(3′,4′-Dichlorophenyl)indan
A solution of cis-3-(3′,4′-dichlorophenyl)indan-1-o1(22.7 g, 0.081 mol) and triethylamine (45 mL, 0.325 mole) in THF (350 mL) was stirred (overhead stirring) under an inert atmosphere while maintaining a solution temperature of −15° C. In a separate flask under inert atmosphere, a solution of methanesulfonyl chloride (12.6 mL, 0.162 mol) in the THF (150 mL) was cooed to −60° C., then added slowly to the solution of cis-3-(3′,4′-dichlorophenyl) indan-1-o1, maintaining the temperature of the reaction mixture below 0° C. After addition was complete, the reaction mixture was stirred for 10 min. at 0° C., then purged with dimethylamine gas (56 g, 1.21 mol). The reaction mixture was allowed to warm to room temperature and stirred for 5 h. The reaction was monitored by TLC against an authentic sample of cis-3-(3′,4′-dichlorophenyl)indan-1-o1 and against an authentic sample of trans-1-(N,N-dimethylamino) 3-(3′,4′-dichlorophenyl)indan. When the reaction was complete, THF was removed under reduced pressure, and the mixture was extracted with ethyl acetate (250 mL). The ethyl acetate layer was removed, and the aqueous layer was extracted with ethyl acetate (2×100 mL). The combined ethyl acetate layers were washed with brine (2×100 mL) and dried over anhydrous sodium sulfate. The ethyl acetate solution was concentrated to give 26 g of 1-(N,N-dimethylamino)-3-(3′,4′-dichlorophenyl)indan as a brown oil. The cis:trans isomeric ratio of the crude amine was 5:95 as determined by HPLC. The crude amine (26 g) was stirred with ethyl acetate (5 mL) for 10 min. After a solid started to form, heptane (45 mL) was added. The mixture was stirred for 1 hour at 15° C., then the precipitated product was collected by filtration, then washed with 40 mL of heptane. The product was dried under high vacuum to give 14 g of product (56%, first crop). The mother liquor was evaporated to an oil. A solution (15 mL) of 10% ethyl acetate in heptane was added to the oil and stirred for 1 hour at 15° C. The precipitated product was collected by filtration, then washed with 20 mL of heptane. The solid was dried under vacuum to give 5.2 g (21%, second crop). HPLC analysis indicated that the two crops contained the same ratio (0.6%) of the undesired cis isomer. The combined crops (19.2 g) were again stirred with a solution (40 mL) of 10% ethyl acetate in heptane for 1 hour at 15° C. The precipitated product was collected by filtration, then washed with 30 mL of heptane. The product was dried under high vacuum to give 15 g (60%) of 1-(N,N-dimethylamino) 3-(3′,4′-dichlorophenyl) indan. Only 0.2% of the undesired cis isomer was detected by HPLC.
EXAMPLE 5
Synthesis of Trans-N,N-Dimethyl [3-(3′,4′-Dichlorophenyl)indan-1-yl] Ammonium Hydrogen Maleate
Trans-1-(N,N-dimethylamino)-3-(3′,4′-dichlorophenyl)indan (13 g, 0.042 mole) was dissolved in ethanol (60 mL) at 50° C. In a separate flask, maleic acid (4.95 g, 0.042 mol) was dissolved in 20 mL of ethanol at 50° C., then added to the solution of trans-1-(N,N-dimethylamino)-3-(3′,4′-dichlorophenyl)indan. The mixture was stirred at 50° C. for 1 h, then at 10° C. for 2 h. The precipitated product was collected by filtration, then washed with cold ethyl acetate (40 mL). The solid was dried under high vacuum to give 13.8 g (77%) of N,N-dimethyl [3-(3′,4′-dichlorophenyl) indan-1-γ1] ammonium hydrogen maleate. The ratio of the undesired cis isomer was 0.3% as detected by HPLC.
The N,N-dimethyl [3-(3′,4′-dichlorophenyl) indan-1-yl] ammonium hydrogen maleate salt was converted back to the free base by stirring it in an aqueous NaHCO 3 solution, then extracting 1-(N,N-dimethylamino)-3-(3′,4′-dichlorophenyl)indan with ethyl acetate.
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The present invention is a method of preparing a 3-aryl-1-indanamine represented by structural formula I:
and physiologically acceptable salts thereof.
In structure I, phenyl ring A can be unsubstituted or substituted with 1-4 substitutents.
R 1 is an aromatic group which can be substituted or unsubstituted.
R 2 and R 3 are each, independently, hydrogen, an aliphantic group, a substituted aliphatic group, an aromatic group, a substituted aromatic group, an aralkyl group, or a substituted aralkyl group. Alternatively, R 2 and R 3 , taken together with the nitrogen substitutent on the indan ring, form a non-aromatic ring system having 1-2 heteroatoms.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority from U.S. Provisional Application No. 60/136,886, filed Jun. 1, 1999, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a valving mechanism for microfluidic devices and more particularly to a valving mechanism which is controlled or actuated by electroosmotic flow (EOF). The invention also relates to a device for delivering fluid reagents which is actuated by EOF.
One example of a valving mechanism for a microfluidic device is described in U.S. Pat. Nos. 4,304,257; 4,858,883 and 5,660,370 to Webster and others. That mechanism employs a flexible sheet or diaphragm which is moved toward or away from a flat non-flexing sheet member having a pair of fluid ports such that flow between the ports is easily regulated. In one embodiment disclosed in U.S. Pat. No. 5,660,370, the diaphragm is attached to the plunger head of a solenoid which is operated to move the diaphragm between blocking and non-blocking positions to activate the valve. In another embodiment disclosed in U.S. Pat. No. 4,858,883, the diaphragm overlies a concavity which is connected to a source of vacuum or pressure which controls the valve. Other microvalve constructions useful in microfluidic devises are described in International Application WO 97/21090. These constructions include a piezoelectric element in which an applied voltage is used to deform the element and block fluid flow; a diaphragm which includes a bimetallic element which is resistively heated to proportionately deflect the diaphragm; an electrostatically activated plunger which is moved into a gap in the microfluidic; and a single-use valve fashioned from polymers which are stretched under defined condition such that when the polymer is subsequently heated, the polymer chains relax and thereby actuate the valve.
SUMMARY OF THE INVENTION
Electroosmotic flow (EOF) has been proposed as a means for moving solutions within a microfluidic device. In accordance with the present invention, two valve constructions are proposed for valves which utilize EOF to control the flow of a fluid between two ports. In one embodiment EOF is used to generate sufficient pressure to actuate a diaphragm valve. In another embodiment, EOF is used to control flow through a membrane which functions as a gate which is opened and closed electrokinetically. Another manifestation of the invention is a fluid delivery device in which EOF is used to move a diaphragm into a reservoir containing a reagent and in turn to meter the reagent into a microfluidic device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a valve construction in the passive state in accordance with one manifestation of the present invention.
FIG. 2 schematically illustrates a valve construction in the de-energized state in accordance with one manifestation of the present invention.
FIG. 3 schematicaly illustrates a valve construction in the energized state in accordance with one manifestation of the present invention.
FIG. 4 is an exploded view of a valve construction in accordance with one embodiment of the invention in which the electrodes have the design shown.
FIG. 5 is an overhead view of a valve construction in which the electrodes have the design shown in accordance with one embodiment of the invention.
FIG. 6 is a schematic illustration of a valve construction in accordance with another embodiment of the invention in which the EOF membrane controls the flow of fluid through a microfluidic device
FIG. 7 is an overhead view of a valve construction in which the electrodes have the design shown in accordance with another embodiment of the invention.
FIG. 8 is a schematic illustration in which the EOF membrane is used in a fluid delivery device for metering fluid from a reservoir to a microfluidic or other device.
DETAILED DESCRIPTION OF THE INVENTION
P. H. Paul, D. W. Arnold, D. J. Rakestraw, Electrokinetic Generation of High Pressures Using Porous Microstructures, Proceedings of the μTAS'98 Workshop Banff, Canada, 13-16 October 1998 p.49 reports that up to 8,000 psi pressure can be generated electrokinetically through a porous media and shows that there is a log-linear relationship between pressure per volt and bead diameter and a linear relationship between pressure and applied voltage. In accordance with the present invention these electrokinetic pressures are used to operate a diaphragm valve. A microfluidic device is provided which includes a valve body having first and second fluid passageways which intersect the surface of the valve body at spaced locations and a valve diaphragm having a surface for making engagement with said valve body surface. A porous membrane is provided between a pair of electrodes and is operatively associated with the diaphragm member and a reservoir of an electrolyte such that when a voltage is applied between the electrodes, the electrolyte is transported through the membrane to effect a change in pressure between the diaphragm and the membrane. The change in pressure actuates the valve. In one embodiment of the invention the EOF of the electrolyte results in application of a positive pressure which closes the valve. In another embodiment the applied voltage causes the electrolyte to move away from the diaphragm and thereby opens the valve.
The valve body and diaphragm can be constructed from materials and using manufacturing techniques that have previously been used in the construction of microfluidic devices with the addition of an EOF membrane and electrodes as described herein. The channel size in the microfluidic devices of the present invention can range from about 50 to 500 microns.
The EOF membrane can be one having an open porous network in which the pore size may range from about 30 angstroms to about 25 microns. The membrane may be about 2 microns to about 25 microns thick and is more typically about 2 to 12 microns thick. The pore size and thickness of the membrane are selected such that an EOF adequate to operate the valve can be established without using voltages which cause electrolysis. Water electrolyzes at about 1.2 to 1.5 volts depending on the electrode. However, by selecting an electrode with a high over-potential (e.g., a boron doped diamond electrode), voltages as high as about 2 volts can be used without electrolysis.
The EOF velocity is usually very small, e.g., about 0.0001 m/sec and is a function of the membrane, the fluid and the voltage. Accordingly, the valve is designed and structured such that the small EOF velocities generate pressures sufficient to operate the valve, e.g., about 10 to 30 psi in conventional microfluidic devices. The valves will not actuate immediately but rather upon application of the electric field, the field will force electrolyte to flow through the membrane. The valve will open or close (depending on the valve design) when sufficient fluid has been pumped through the membrane to generate enough pressure to actuate the valve.
The EOF membrane will be formed by a material which can carry a charge upon the inner surfaces of the walls of its pores such that when it is placed in and ionic solution it will create an electric double layer which is characteristic of electroosmotic. Most substances will acquire a surface electric charge when brought into contact with an aqueous medium via a charging mechanism such as ionization, ion adsorption, or ion dissolution. Additionally, the membrane must be inert to the fluids with which the microfluidic is used and is desirable a material that can be readily bonded to the valve body. Preferably the membrane will be bonded within the microfluidic device using an adhesive or a bonding technique such as heat sealing, but mechanical constructions using clips and other fasteners could also be used for some applications. Two materials which are commercially available and have been used experimentally are track etched polycarbonate and track etched polyimide. If the membrane is so thin that it is not able to maintain enough pressure to actuate the valve, e.g., the membrane flexes readily under pressures less than 20 psi, a contiguous structural supporting material such as cellulosic or synthetic paper, a metal or synthetic wire mesh may be used in conjunction with the membrane to prevent the membrane from yielding to the EOF pressure.
In order to generate the EOF, an electric field is deployed across the membrane. Typically this field can run from about 100 v/cm to 1000 v/cm but those skilled in the art will recognize that the field controls the EOF velocity and weaker fields could be used but the valve will operate more slowly and stronger fields could be used provided that they do not result in electrolysis. As explained above, due to the electrolytic limits of water, the electric field generally must be effected using less than 2 volts. This field is most conveniently established using thin film electrodes of a type known in the art. An electrode is preferably selected which does not result in dendrite formation or the formation of precipitates and which does not produce appreciable gas through electrolysis. Silver or platinum electrodes are well known and can be used but other electrodes having a higher overpotential which can be sputter deposited may prove to be more desirable for use.
FIGS. 1-3 schematically illustrate one embodiment of the invention wherein a microfluidic device 10 contains a first channel 12 and a second channel 14 having respectively ports 16 and 18 which open on a valve area 20 on one surface of the microfluidic 10 . The microfluidic is constructed from interfacing lower element 30 and upper element 32 which have been micromachined at the interface to provide the channels 12 and 14 . A diaphragm 22 overlies the ports 16 and 18 . The diaphragm 22 is a fluid impermeable but flexible partition such as a polyimide or a polyurethane film. Juxtaposed with the diaphragm is the EOF membrane 24 . This EOF membrane seals a reservoir 26 containing an electrolyte. In FIG. 1, the valve is shown in a passive state in which no fluid is flowing in the microfluidic. When a fluid is pumped through the microfluidic as shown in FIG. 2, the fluid easily deflects the diaphragm/EOF membrane construction 22 / 24 and passes between the first and second channels 12 and 14 through the ports 16 and 18 . The microfluidic includes a pair of electrodes which is not shown in FIGS. 1-3. In the illustrated in FIG. 3 when an electric field is applied by means of the electrodes, the electrolyte in reservoir 26 is transported through the EOF membrane 24 and because the diaphragm is impermeable, the electrolyte accumulates in the space 28 between the diaphragm and the membrane and produces a positive pressure on the fluid impermeable diaphragm 22 forcing it to seal the ports 16 and 18 . To open the valve, the electric field can be reversed such that electrolyte is transported back into the reservoir 26 so that fluid pressure in channels 12 and 14 moves the diaphragm away from the ports 16 and 18 .
FIG. 4 is an exploded view of a valve construction in accordance with this embodiment of the invention showing that the reservoir is formed from a electrolyte containment layer 33 which may be formed from the same material as the microfluidic halves 30 and 32 or from a different dimensionally stable and inert material, and a flexible containment layer 35 which is conveniently formed of a material such as a polyester or polyimide film. The containment layer 35 is preferably sufficiently flexible so that a negative pressure which interferes with electroosmotic flow is not produced in the electrolyte chamber as the electrolyte moves from the reservoir 26 into the space 28 . In lieu of a flexible containment layer, the reservoir could be vented.
The EOF membrane 24 is sandwiched between a pair of thin film electrodes. These electrodes are formed from materials and in a manner that is well known in the art. In the illustrated embodiment, one electrode 34 is located on the side of the EOF membrane 24 which faces the reservoir and the other electrode 36 is affixed to the diaphragm 22 . The electrodes can be shaped as shown in top view in FIG. 5 in which one is annular (electrode 34 ) and the other 36 is a disk or they can be shaped differently provided that they generate an electric field across the EOF membrane which transports fluid. The electrodes will include tabs 38 for connecting them to an external power supply. The electrolyte is preferably an aqueous solution of a monovalent salt such as sodium borate. Typically a concentration less than about 0.1 μM to 1.0 mM is used.
The microfluidic halves, the diaphragm, the EOF membrane and the reservoir can be assembled using one or a combination of techniques known in the art including using adhesives, self bonding films, melt flow or mechanical clamping.
In another embodiment of the invention as schematically illustrated in FIG. 6, the diaphragm is omitted and the EOF membrane is interposed in the channel as a “gate” that is opened, partially opened or closed using the electric field strength. For this embodiment of the invention, the fluid passing through the microfluidic must have a weakly ionic character. In this embodiment of the invention a microfluidic device 100 includes a first channel 102 and a second channel 104 which open onto each other at common ports 106 and 108 . Interposed between these ports is an EOF membrane 110 which includes electrodes 114 and 112 (FIG. 7) on each side thereof. The electrodes can have the same construction as shown in FIG. 5 . When the electric field is zero or very low, essentially no fluid passes through the membrane. When an electric field is applied, the EOF membrane 110 transports fluid across the membrane and enables flow between the channels 102 and 104 . In theory, by varying the field strength one should be able to control the rate of flow through the membrane.
In another embodiment of the invention an EOF membrane is used as an actuator for a fluid delivery system. This embodiment is illustrated in FIG. 8 . The dispenser 200 includes a reservoir of electrolyte 202 , which is formed by a containment layer 204 and a pair of flexible bladder diaphragms 206 / 207 . An EOF membrane 208 is provided inside the electrolyte reservoir 202 on the electrolyte reservoir side of the bladder diaphragm 207 . A second reservoir 210 contains a solution, such as a solution of a reagent, that is to be delivered. This reservoir includes a small outlet 212 which may feed a microfluidic or a reagent delivery device. As in the other embodiments of the invention, the EOF membrane 208 is used in conjunction with a pair of electrodes analogous to FIGS. 5 and 7. By applying a voltage across the anode and cathode, the electrolyte is transported from the reservoir 202 across the EOF membrane 208 into the space 214 between the EOF membrane 208 and the bladder diaphragm 207 . This results in a fluid pressure being applied to the diaphragm 207 which causes the diaphragm to expand into the reservoir 210 thereby forcing the fluid from the reservoir via the outlet 212 . At the same time, the bladder 206 and the EOF membrane 208 are drawn together as shown in FIG. 8 ( b ). While the embodiment of FIG. 8 shows the electrolyte chamber being formed from two flexible bladder members, this is not an essential element of the invention. The electrolyte chamber could be formed using a single flexible bladder or the electrolyte chamber could be vented so that a negative pressure which would interfere with the EOF flow is not created in the electrolyte chamber as the electrolyte is transported.
In summary, one manifestation of the invention is a microfluidic module having fluid flow channels therein, at least one fluid flow channel being in communication with a diaphragm valve, said diaphragm valve including a flexible fluid impermeable diaphragm and a fluid permeable member contiguous with said fluid impermeable diaphragm, a reservoir of an electrolyte in fluid communication with said fluid permeable member, a cathode positioned on one side of said fluid permeable member and an anode positioned on the opposite side of said fluid permeable member such that when a voltage is applied to said electrodes, said electrolyte is transported through said fluid permeable member and said transported electrolyte applies fluid pressure to said diaphragm thereby closing said valve.
In a more particular manifestation of the invention, the fluid permeable member is a porous membrane which is interposed between said fluid impermeable diaphragm and said reservoir such that when a voltage is applied between said electrodes, electrolyte is transported from said reservoir to said diaphragm where fluid pressure is applied to close said valve.
Another manifestation of the invention is a module having fluid flow channels therein, at least one fluid flow channel having a fluid permeable membrane situated therein such that fluid passing through said channel must flow through said membrane, said membrane having a cathode on one side thereof and an anode on the other side such that when a voltage is applied to said electrodes, fluid flows selectively through said channel and when no voltage is applied to said electrodes, essentially no fluid flows through said channel whereby the flow of fluid through said channel is controlled electrokinetically by said membrane.
Still another manifestation of the invention is a fluid delivery system which includes a first reservoir of an electrolyte, a second reservoir of a fluid to be delivered by said delivery system, an outlet in said second reservoir, a flexible fluid impermeable diaphragm and a fluid permeable diaphragm interposed between said first and second reservoirs, said fluid permeable diaphragm having electrodes positioned on each side thereof wherein by applying a voltage to said electrodes, said electrolyte is transported from said first reservoir through said membrane and said electrolyte expands said fluid impermeable membrane into said second reservoir containing said deliverable fluid thereby forcing said fluid through the outlet in said second reservoir.
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In one embodiment, a fluidic module, such as a microfluidic module, has a fluid-flow channel, an electroosmotic flow membrane positioned in the channel, and a cathode located on one side and an anode located on the other side of the membrane so that an electrolyte in the channel is transported through the membrane in the presence of a voltage. In another embodiment, the channel has a port, a flexible and fluid-impermeable diaphragm is added, the electrolyte is contained in a reservoir, and the membrane moves the bladder which acts as a valve for fluid leaving the channel through the port. In a further embodiment, electrolyte in a first reservoir is transported through the membrane to move the bladder to force fluid out of a second reservoir.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to provisional application Ser. No. 60/237,045 filed Oct. 2, 2000, entitled Plastic Swing Check Valve, and which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to an apparatus for allowing the transfer of bulk materials or fluids in containers, pipes or hoses, in one direction, but not in the opposite direction, and more particularly, to a lighter weight and more efficient swing check valve for use in the transfer of such materials or fluids.
[0004] In the trucking industry, dry bulk materials and fluids (i.e., liquids and gasses) must regularly be transferred between truck trailer containers and either fixed storage containers or mobile containers, such as on ships planes or other trucks. In order to facilitate rapid transfer of the bulk materials and fluids, and to limit leakage, swing check valves are typically placed at the inlet ports on the containers. These valves have an internal pivoting gate, referred to as a “poppet,” that swings out of the way when the material flows in one direction, and drops in place to close the valve with a gasket seal when the material attempts to flow in the opposite direction. The valves are self-contained and require no external actuation other than the material flow itself.
[0005] Conventional valves for most dry bulk trailer use are typically constructed of aluminum. Although lighter in weight than most metals, aluminum is significantly heavier than many materials, including plastics. In an application such as trucking, where large valves are required and carrying capacities are limited by loaded vehicle weight, any amount of weight reduction in the check valve directly results in greater load capacity, and thereby improved efficiency and reduced costs.
[0006] In addition, when a bulk material or fluids (the transferred product) are transferred between storage containers, the transferred product must pass through the valve at a very rapid rate. Any irregularities (including irregularities due to pitting) in the shape of the check valve's inner surface will create turbulence in the material transfer that can slow the transfer. The greater the extent of the irregularities, the greater the turbulence and the greater the inefficiency in material transfer. Accordingly, it is desirable for the inner surface to be as spherical, smooth and free from pits and protrusions as possible. However, not only are the surfaces of the access port and poppet in a conventional check valve irregular in shape, conventional check valves exhibit burs and pits on the valve's inner surfaces from the casting process that finishing does not fully remove. These all result in undesirable excess turbulence during material flow.
[0007] Furthermore, check valves require regular inspection and maintenance. Each valve has an access port for this purpose, generally located at the top of the valve. Complete inspection can only be accomplished by removing the access port, an external pivot pin assembly for the poppet, and then the internal poppet assembly. The same procedure must be followed to remove the poppet gasket for replacement, the most common maintenance and repair need on check valves. Because the gasket is typically glued to the poppet, the entire poppet assembly often must be replaced when the gasket fails.
SUMMARY OF THE INVENTION
[0008] The present invention resides in a light weight check valve for use in bulk material transfers, and more particularly for use on truck trailer containers where the reduced weight over conventional metal valves provides efficiency benefits. The check valve is preferably made of an appropriate plastic which can withstand the bulk material or fluid passing through the check valve. Plastic is preferred due to the smooth surface that can be formed, and due to its ability to withstand pitting. Hence, the surface will remain smooth (i.e., will not become severely pitted, which can cause turbulent fluid flow through the valve). However, the check valve can also be made of other light weight materials. The poppet and access port in the present invention are configured such that when the check valve opens to allow air and material flow, the combined interior surfaces of the valve, excluding the inlet and outlet flow ports, mate smoothly against one another to form a nearly spherical shape. This, in combination with the smooth surface of the valve, reduces the amount of turbulence in the valve, increases flow efficiencies and enables increased flow rates.
[0009] Further, the poppet assembly and access port are coupled internally so that both can be removed as a single unit for easy and rapid inspection of the entire valve. A simple seal such as an O-ring, or preferably a Quad-Ring® (available from Minnesota Rubber of Minneapolis, Minn.), located on the rim inside the valve against which the poppet closes, forms the poppet seal. In contrast to conventional check valves, this Quad-ring seal can be easily and rapidly replaced when necessary.
[0010] The present invention is readily adaptable to virtually any size check valve, and can readily be combined with numerous interfaces for connection to a variety of containers, pipes and hoses.
[0011] Additional features of the present invention will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a perspective view a first embodiment of a fully assembled check valve of the present invention;
[0013] [0013]FIG. 2 is a perspective view of the check valve with the lid assembly removed;
[0014] [0014]FIG. 3 is a bottom view of a lid gasket;
[0015] [0015]FIG. 4 is a perspective view of the seal mount;
[0016] [0016]FIG. 5 is a cross-sectional view of the seal mount;
[0017] [0017]FIG. 6 is a cross-sectional view of the fully assembled check valve with the gate closed, as viewed from the center of the valve toward the input side of the valve
[0018] [0018]FIG. 7 is a side elevational view of a lid assembly of the check valve;
[0019] [0019]FIG. 8 is a perspective view of the lid assembly;
[0020] [0020]FIG. 9 is a bottom plan view of the lid assembly;
[0021] [0021]FIG. 10 is a perspective view of a pin used to in lid assembly;
[0022] [0022]FIG. 11 is a perspective view of a poppet of the check valve;
[0023] [0023]FIG. 12 is a cross-sectional view of the poppet;
[0024] [0024]FIG. 13 comprises a top plan view of a seal-ring used in conjunction with the poppet;
[0025] [0025]FIG. 13A is a cross-sectional view of the seal ring;
[0026] [0026]FIG. 14 is a top plan view of a spring for the poppet;
[0027] [0027]FIG. 14A is a side elevational view of the spring;
[0028] [0028]FIG. 15 is a perspective view of the a second embodiment of the check valve, when fully assembled;
[0029] [0029]FIG. 16 is a perspective view of the lid gasket for the second embodiment.
[0030] [0030]FIG. 17 is a cross-sectional view of the fully assembled check valve of FIG. 15 with the gate closed, as viewed from the center of the valve toward the input side of the valve;
[0031] [0031]FIG. 18 is a side elevational view of the lid assembly of the check valve of FIG. 15;
[0032] [0032]FIG. 19 is a cross-sectional view lid assembly taken along line B-B of FIG. 18 showing of the hinge area of the lid assembly;
[0033] [0033]FIG. 20 is a perspective view of the lid assembly of the check valve of FIG. 15;
[0034] [0034]FIG. 21 is a bottom plan view of the lid;
[0035] [0035]FIG. 22 is a cross-sectional view of the lid assembly taken along line A-A of FIG. 21;
[0036] [0036]FIG. 23 is an end elevational view of the lid assembly;
[0037] [0037]FIG. 24 is a perspective view of the poppet for the check valve of FIG. 15;
[0038] [0038]FIG. 25 is a side elevational view of the poppet;
[0039] [0039]FIG. 26 is an additional side view of the lid in the second embodiment; and
[0040] [0040]FIG. 27 is a cross-sectional view of the lid assembly taken along line B-B of FIG. 26 showing the hinged connection of the poppet to the lid.
[0041] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] A first embodiment of a assembled check valve A is shown in FIG. 1. The check valve is preferably made of a plastic which can withstand the materials or fluids which flow through the check valve. In particular, preferably the plastic will withstand pitting due to corroding effects of the material which passes through the check valve so that the inner surfaces of the check valve will remain smooth. A preferred plastic is a polyamide (such as Grilon PVZ-5H available from EMS-Chemie (North America), Inc. of Sumter, N.C.) combined with Nylon and with impact modifiers. Other preferably light weight materials which will withstand the environment to which they are subjected and which will withstand pitting can be used as well.
[0043] The check valve A includes a hollow body 1 and a lid assembly 2 fixedly attached to the body 1 by six bolts 3 . A thin, flat gasket 12 forms a seal between the body 1 and the lid assembly 2 . The body 1 comprises a generally spherical shape that transforms into two parallel, generally square shaped, fitting plates 6 a and 6 b at opposite ends of the body 1 . Each fitting plate 6 a,b has an end face 9 , generally flat perimeter faces 10 , and a thickness equal to approximately one tenth the overall length of the body 1 . Brass nut inserts 11 are imbedded in the end faces 9 at each of the eight corners of the fitting plates 6 a and 6 b to facilitate ready attachment between the valve A and containers, pipes, hoses or other external devices to which the valve A can be attached.
[0044] The fitting plates 6 a and 6 b have an input port 4 and an output port 5 , respectively to allow dry bulk material or fluids to flow through the input port 4 , through the body 1 , and through the output port 5 . The input port 4 and output port 5 are coaxial, each having equal diameters and a circular rim 8 located at the end faces 9 , perpendicular to the central axis of the ports 4 and 5 . A circular groove 7 , concentric with the ports 4 and 5 , is formed in each end face 9 of the fitting plate 6 . The groove 7 has an inner diameter slightly greater than that of the rim 8 , and a depth and outer diameter configured to accommodate standard compression Quad-ring seals (available from Minnesota Rubber of Minneapolis, Minn.) for sealing the valve to, for example, a container or a supply hose.
[0045] To minimize cost and weight, the bodies of the fitting plates 6 a and 6 b comprise webbed members between the outer edges of the groove 7 , the supporting rings about the brass nut inserts 11 , and each of the sidewalls supporting the perimeter faces 10 .
[0046] The body 1 defines a cavity C (FIG. 2), wherein the bottom half of the cavity C comprises a smooth, elongated hemispherical surface 13 truncated at the ports 4 and 5 . The surface 13 ends with ledges 14 at the approximate mid-height of each side of the body 1 between the ports 4 and 5 . The ledges 14 , thereupon extend radially a short distance beyond the surface 13 , and run laterally along the length of the interior of the body 1 from the input port 4 to the output port 5 . Sidewalls 16 of the cavity C extend vertically from both of the ledges 14 to a horizontal rim 17 at the top of the body 1 , that is coplanar with the uppermost perimeter faces 10 of the ports 4 and 5 .
[0047] The inlet and outlet ports 4 and 5 are defined by circular surfaces 15 extending axially from the cavity C. A detent is formed in the cavity C above surfaces 15 . The detent if formed by a curved surface 18 that runs laterally from an approximate 45 degree arc, centrally located along the top of the outermost perimeter of the circular surface 15 , toward the fitting plate 6 a for approximately half the length of the input port 4 . Another sidewall 19 rises vertically, from the edge of the surface 18 opposite the ledge 15 , to the rim 17 . Two parallel sidewalls 20 rise vertically from the lowermost edges of the surface 18 to the rim 17 , each being perpendicular to, and intersecting, the sidewall 19 along their outermost edges.
[0048] Two end faces 21 , coplanar with one another and parallel to the end face 9 of the fitting plate 6 a, join the faces 20 , the ledge 15 , the sidewalls 16 and the rim 17 in the cavity C, on either side of the input port 4 . Each face 21 , on its respective side of the port 4 , extends from the innermost edge of the face 19 , to an arc of the circular ledge 15 that runs between the intersections of the ledge 15 with the face 20 and the sidewall 16 , to the edge of the sidewall 16 that runs vertically from the point on ledge 14 nearest the port 4 to the rim 17 , and to rim 17 .
[0049] A gasket groove 22 extends along the rim 17 at the edge of the cavity C in the body 1 . The gasket groove 22 is sized and shaped to accommodate a ridge 12 a (FIG. 3) on one side of the gasket 12 (FIG. 3). The cross-sectional dimensions of the groove 22 and the gasket ridge 12 a are such that the gasket ridge 12 a fits snugly into the groove 22 when the gasket 12 is placed atop the body 1 of the valve A.
[0050] A seal mount 23 (FIGS. 4 and 5) is positioned in the ports 4 and 5 to mount a seal in the ports 4 and 5 . The seal is circular in plan and having generally square in crosssection (FIG. 5). The seal mount 23 comprises a cylindrical inner surface 24 with a diameter equal to the diameter of the input port 4 , a cylindrical outer surface 25 with a diameter equal to the outer diameter of the port surface 15 , and a back face 26 and a front face 27 , such that the surfaces 24 and 25 are concentric. A circular groove 28 , shaped and sized to hold a seal ring (such as a Quad-Ring® seal available from Minnesota Rubber of Minneapolis, Minn.), runs the full circumference of the front face 27 . Another groove 29 , having a generally square cross-section, runs the full circumference of the outer cylindrical surface 25 . The seal mount 23 is secured in the ports 4 and 5 with the back face 26 against the port surface 15 . The seal is then received in the seal mount groove 28 .
[0051] The lid assembly 2 (shown in detail in FIGS. 7 - 12 ) comprises a lid 30 , two bushings 31 , two pins 32 , a poppet 33 , and a spring 35 . A seal plate 36 at the top of the lid 2 (FIGS. 7 and 8), having a thickness approximately equal to that of the sidewalls 16 of the body 1 , generally conforms in shape to the top of the body 1 without the end plates 6 a and 6 b, having an input end 36 a and an exit end 36 b. Six ears 37 surround the seal plate 36 , each having a central bore 38 with a diameter slightly larger than that of the bolts 3 to allow the bolts to turn freely in the bores 38 with little or no lateral or angular movement.
[0052] Rising from the center of the seal plate 36 is a dome 39 , having a height approximately three times that of the seal plate 36 , and a radius slightly larger than the cross-sectional radius of the centermost section of the elliptical portion of the cavity C. The dome 39 is positioned on the seal plate 36 such that it contains a diameter d, running perpendicular to the input and exit ends 36 a and 36 b, that bisects the seal plate 36 . Descending perpendicularly from the seal plate 36 is a hollow cylindrical neck 40 , being concentric with, and having an outer diameter approximately equal to that of, the dome 39 . Also descending perpendicularly from the seal plate are two ears 41 , both parallel to and approximately one half the radius of the dome 39 from the diameter d. The ears 41 are each connected in part to the side of the neck 40 , have a height less than that of the sidewalls 20 of the cavity C, and a thickness equivalent to that of the seal plate 36 . The dimensions and locations of the ears 41 are such that the ears 41 can readily fit between the sidewalls 20 of the detent above the inlet 4 .
[0053] Through each of the ears 41 runs a bore 42 , having a central axis parallel to the seal plate 36 and perpendicular to the diameter d, each bore 42 being axially aligned with one another and having a diameter generally equal to the outer diameter of the bushings 31 . Above the ears 41 , a structural member 43 rises from the seal plate 36 , and extends along an ascending plane to a plane above and parallel with the seal plate 36 to intersect with the dome 39 at approximately half the height of the dome 39 , therein providing additional structural support for the ears 41 .
[0054] Descending from the neck 40 of the lid 2 is a generally dome shaped body 44 , having outer walls 45 shaped to conform to, and fit snugly within, the sidewalls 16 of the cavity C, and further shaped such that their lowest edges abut against, for the full length of, the ledge 14 of cavity C. Beneath the dome 39 and inside the neck 40 and body 44 (FIG. 9), the lid 2 houses an interior dome 47 that opens to expose a portion of the underside of the seal plate 36 and the inner faces of the ears 41 . For added strength, a rib 46 spans the center of the inner dome 45 from between the ears 41 to the inner surface of the neck 40 opposite the ears 41 .
[0055] Each of the bushings 31 is coaxially mounted in one of the ears 41 (FIG. 6), such that the outermost faces of the opposing bushings 31 are flush with the outermost faces of the ears 41 . The pin 32 extends through the bushings 31 , such that the ends of the pin 32 are generally flush with the outermost faces of the ears 41 and the pin 32 may rotate freely within the bushings 31 . Numerous straight knurls 47 (FIG. 10) score the full circumference of the pin 32 , each parallel to the central axis of the pin 32 and running the length between the innermost faces of the bushings 31 , the knurls being distanced slightly from the bushings 31 so as not to hinder the free rotation of the pin 32 within the bushings 31 .
[0056] A sleeve member 48 of the poppet 33 (FIG. 11) attaches the poppet 33 to the pin 32 , the poppet 33 being held fixedly to the pin 32 by the knurls 47 , such that the poppet 33 and the pin 32 rotate in unison about the pin's central axis within the bushings 31 . From the sleeve 48 , the poppet transitions into a flat outer ring 49 that surrounds a dome 50 . Rising above and spanning across the convex side of the dome 50 are six structural ribs 51 , each radiating from the center of the dome 50 to the outer edge of the outer ring 49 . On the opposite side of the poppet 33 from the ribs 51 (FIG. 12), a channel 52 , having a rectangular cross-section with a horizontal tongue 53 midway up the innermost side of the rectangle, is formed about the full circumference of the front face of the outer ring 49 .
[0057] The channel 52 has a depth, and inner and outer diameters equal to the same dimensions of the ring-shaped brass insert 34 (FIG. 13). The insert 34 has a small channel 54 , located on the inner edge of the insert 34 (FIG. 13 a ), having dimensions equal to the dimensions of the tongue 53 on the poppet 33 , such that the tongue 53 is received in the channel 54 . When the insert 34 is pressed into the channel 52 of the poppet 33 with sufficient force, the tongue 53 seats snugly into the channel 54 in the insert 34 to secure the insert 34 in place on the poppet 33 .
[0058] The spring 35 (FIG. 14), comprised of a single, contiguous, stainless steel spring wire, is generally U-shaped, having a generally U-shaped base 55 having legs 55 a and residing in a plane p, a coil 56 located at the end of each leg 55 a, and pair of parallel tails 57 extending from the double coils 56 to the top of the spring 35 . The coils 56 share a common central axis, and have an inner diameter slightly greater than the outer diameter of the pin 32 . The base legs 55 a each have a bend 58 , of approximately 45 degrees, located between the base of spring 35 and each double coil 56 . The bend 58 raises the double coils 56 above the plane p containing the base 56 . The tails 57 extend from the double coils 56 perpendicularly back toward, and through the plane p. The spring 35 is thus configured to enable the coils 56 to fit around, and rotate freely about, the pin 32 , while the base 55 presses against the rib 51 of the poppet 33 , nearest the sleeve 48 , and the tails 57 press against that portion of the underside of the seal plate 36 between the ears 42 .
[0059] The body 1 , lid assembly 2 , and poppet 33 of the check valve A are all constructed of a light weight plastic material, such as a polyamide available from EMS-Chemie under the name Grilon PVZ-5H with 50% G.F. Nylon and an impact modifier. This material, and others like it, provide adequate strength for the check valve, along with the advantages of having a lighter weight than metals, including aluminum, and smoother member surfaces.
[0060] In use then, when seal mount 23 is properly seated on the port surface 15 in the cavity C of the valve A, a seal of appropriate dimensions is properly seated in the groove 28 of the seal mount 23 , and the lid assembly 2 is properly and fully placed within the body 1 of the valve A, the front face of insert 35 on the poppet 33 will align concentric to and flush with the seal in the seal mount 23 . This is the “closed” position for valve A. The spring 35 imparts a force against the ribbed side of the poppet 33 that maintains the poppet in the “closed” position.
[0061] When a sufficiently strong counter force is applied to the concave side of the dome 50 of the poppet 33 , such as when bulk material is being directed through the inlet port 4 of the valve A, the poppet swings up against the inner dome 45 of the lid 30 . The shape of the concave side of the poppet 33 in conjunction with the exposed walls of the inner dome 45 of the lid 30 and the elongated hemispherical surface 13 in the body 1 , combine to form a generally spherical cavity through which the bulk material passes inside the valve A. This shape creates much less turbulence than the shapes of conventional swing valves and thereby offers greater transfer efficiency and throughput velocities. Should the flow of material begin to reverse for any reason, the poppet 33 will quickly return to, and remain in, the “closed” position to prevent the possibility of any such backflow.
[0062] Finally, because the lid 30 , the bronze bushings 31 , the pin 32 , the poppet 33 , and the brass insert 34 all comprise a single unitized lid assembly 2 , the entire core of the check valve A can be quickly and readily examined by simply removing the lid assembly 2 from the body 1 . This exposes the Quad-ring seal in the seal mount for ready examination and replacement, as well as facilitating rapid examination and maintenance of the lid assembly 2 itself.
[0063] A second embodiment of the check valve A′ is shown in FIGS. 15 - 25 . The check valve A′ is substantially similar to the check valve A of FIG. 1. It includes a body 101 identical to the body 1 of valve A. A lid assembly 102 closes the body 101 . The lid assembly 102 is slightly different from the lid assembly 2 . The lid assembly 102 includes a seal plate 136 having a perimeter sized and shaped to close the open top of the body 101 . A series of ears 137 surround the seal plate 36 . The ears have holes 138 through which bolts pass to secure the lid assembly 102 to the body 101 .
[0064] A gasket 112 is positioned on the upper edge of the body walls, and the seal plate 136 is placed on top of the gasket. The gasket 112 thus forms a fluid tight seal between the body 101 and the seal plate 136 . The gasket 112 is corresponds in shape to the circumferential shape of the body walls. The gasket 112 includes a rib 112 a which fits in a groove in the upper edge of the body wall and a plurality of ears 112 b which correspond in size, shape, and position to the ears of the seal plate 136 . Hence, the bolts pas through the gasket ears when the cover assembly 102 is secured to the body 101 . The gasket 112 also includes legs 112 c which are positioned effectively at the four corners of the gasket 112 . The gasket legs 112 c help locate the gasket 112 on the body 101 .
[0065] A dome 139 rises up from the center of the seal plate 136 . The dome 139 has a radius slightly larger than the cross-sectional radius of the centermost section of the elliptical portion of the cavity C. The dome 139 is positioned on the seal plate 136 such that it contains a diameter d, running perpendicular to the input and exit ends 136 a and 136 b, that bisects the seal plate 136 . A plurality of intersecting ribs 139 a extend over the outer surface of the dome 139 .
[0066] A cylindrical neck 140 descends from the seal plate 136 . The neck 140 is concentric with, and has an outer diameter approximately equal to that of, the dome 139 .
[0067] A pair of opposed ears 141 also descend from the seal plate 136 . As best seen if FIGS. 19 and 25, the ears 141 have a circumferential wall 141 a defining a pocket 141 b with a floor 141 c. A central opening 142 is formed in the pocket floors 141 c. The openings 142 of the opposed ears 141 are aligned with each other.
[0068] A truncated dome shaped body 144 descends from the neck 140 . The dome shaped body 144 has arced side walls 145 ending with a flat, vertical face 145 a shaped to conform to, and fit snugly within, the sidewalls 16 of the cavity C, and further shaped such that their lowest edges abut against, for the full length of, the ledge 14 of cavity C. The dome shaped body 144 has an inner surface 147 which defines a radius corresponding to the radius defined by the lower portion of the cavity in the body 101 . For added strength, a rib 146 spans the center of the inner dome 147 from between the ears 141 to the inner surface of the neck 140 opposite the ears 141 . The dome shaped body, in conjunction with the lower section of the valve body cavity C defines a substantially spherical chamber when the cover assembly 102 is mounted on the body 101 , with entrance and exit ports through which fluid material flows.
[0069] As seen in FIG. 25, a pin 132 extends through each of the ear holes 142 . In FIG. 25, two pins are used, which of which extends into the space between the ears 141 . However, a single pin, which spans the distance between the ears 142 (such as used in the valve A) can also be used. The pin 132 includes a slot 132 a extending across the potion of the pins 132 in the ear pockets 141 b.
[0070] The poppet 133 is pivotally mounted to the lid assembly 102 by means of the pins 132 . The poppet has a main, generally circular body 133 a with a sleeve member or arm 148 . The arm 148 has a hole 148 a into which the pins 132 extend. The pins 132 are sized to be frictionally received in the sleeve hole 148 a. Hence, the pins 132 act as axles for the poppet 133 , and rotate in the ear holes 142 as the poppet 133 is pivot relative to the dome shaped body 144 .
[0071] The poppet body 133 a includes a flat outer ring 149 from which the sleeve member 148 extends. The ring 149 surrounds a dome 150 . Rising above and spanning across the convex side of the dome 150 are structural ribs 151 , each radiating from the center of the dome 150 to the outer ring 149 . On the opposite side of the poppet 33 from the ribs 51 (FIG. 12), a channel 52 , having a rectangular cross-section with a horizontal tongue 53 midway up the innermost side of the rectangle, is formed about the full circumference of the front face of the outer ring 49 .
[0072] A torsion spring 135 is received in the pockets 141 b of the ears 141 . The torsion spring is journaled about the each pin 132 and includes a coil 135 a having ends 135 b and c. The end 135 b of the spring 135 is bent to be received in the pin slot 132 a, and the end 135 c extends outwardly from the coil to engage the under side of the lid assembly 102 , as seen in FIG. 26.
[0073] The poppet 133 is shown in its down position in FIG. 26, in which position, the poppet would close the inlet port into the valve body 101 . As can be appreciated, when the poppet 133 is rotated counterclockwise (with respect to FIG. 26) into the cavity, the end 135 b of the torsion spring 135 will engage the underside of the lid 136 . The interaction of the spring, as such a point, between the pins 132 (which are engaged by the spring) and the lid 136 , will create a spring force which will urge the poppet 133 back to the position shown in FIGS. 26 and 27.
[0074] As can be appreciated, in both embodiments of the check valve, the lid assembly and the body define complementary cavities, such that, when the lid assembly is mounted to the body, they form a spherical chamber through which the flowable material passes. Further, the walls of the body and the lid assembly are formed such that there is a smooth transition on the chamber wall between the body and the lid assembly. Hence, the flowable material is presented with a substantially smooth surface to reduce the potential of turbulence within the valve, and increase throughput through the valve. Lastly, the lid assembly, to which the poppet is hingedly mounted) in both embodiments, is removably mounted to the body. Thus, by removing the bolts or screws which secure the lid assembly to the body, the lid assembly and poppet can be removed. This makes for easy inspection (and replacement if necessary) of the poppet and its associated seals.
[0075] As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. For example, although the valve lid assembly 2 and body 1 are preferably made from plastic, they can be made from other materials as well. Additionally, the inner surface or wall of the lid assembly and body can be coated with a material which will resist pitting, if a different material is required for the exterior surfaces of the check valve. This will produce a valve in which the walls of the chamber are lined with a material which will substantially resist pitting.
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The present invention relates to a light weight check valve for use in bulk material transfers that incorporates a smooth, generally spherical interior cavity to minimize flow inefficiencies. The check valve is made from two portions: a body portion and a lid assembly which is removably mounted to the body portion. The gate valve, or poppet, is hingedly mounted to the lid assembly. Hence, when the check valve assembly is opened for inspection, by removing the lid assembly, the poppet is removed along with the lid assembly, to allow for easy inspection of the poppet.
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FIELD OF THE INVENTION
[0001] The invention relates to the field of processing of raw materials, especially raw plant- or animal-derived materials. More specifically, the invention relates to disintegration of lignocellulose from lignocellulose containing materials, like wood or other plant material, chitin from exoskeletons from Crustacea like crabs and shrimps, and proteins such as keratin from pig hair or chicken feather for production of chemicals, e.g. as sugars from carbohydrates for fermentation processes such as the production of (bio)ethanol or as keratin hydrolysates for applications in paper or cosmetics. Even more specifically, the present invention relates to those processes in which superheated steam is brought in direct contact with raw materials in a single processing step.
BACKGROUND OF THE INVENTION
[0002] Lignocellulosic biomass refers to plant biomass that is composed of cellulose, hemicellulose, and lignin. This biomass comes in many different types, which may be grouped into four main categories: (1) wood residues (including sawmill and paper mill discards), (2) municipal paper waste, (3) agricultural residues (including corn stover and sugarcane bagasse), and (4) dedicated energy crops (which are mostly composed of fast growing tall, woody grasses). In all these categories the carbohydrate polymers (cellulose and hemicelluloses) are tightly bound to the lignin, by hydrogen and covalent bonds.
[0003] Fermentation of lignocellulosic biomass to ethanol and butanol is an attractive route to process energy feedstocks that supplement the depleting stores of fossil fuels. Biomass is a carbon-neutral source of energy, since it comes from dead plants, which means that the combustion of ethanol produced from lignocelluloses will produce no net carbon dioxide in the earth's atmosphere. Also, biomass is readily available, and the fermentation of lignocelluloses provides an attractive way to dispose of many industrial and agricultural waste products. Finally, lignocellulosic biomass is a renewable resource. Many of the dedicated energy crops can provide high energy biomass, which may be harvested multiple times each year.
[0004] One barrier to the production of ethanol from biomass is that a large fraction of the sugars necessary for fermentation present in the form of lignocellulose. Lignocellulose has evolved to resist degradation and to confer hydrolytic stability and structural robustness to the cell walls of the plants. This robustness or “recalcitrance” is attributable to the crosslinking between the polysaccharides (cellulose and hemicellulose) and the lignin via ester and ether linkages, thus creating a material that is physically hard to access. This means that for an efficient use of the components from the lignocellulose, said lignocellulose should be disintegrated and/or separated and/or decrystallized, to allow enzymes to be able to contact the cellulose and hemicellulose for conversion into oligo- and monosaccharides, which then in turn can be used for many purposes, e.g. for bio-ethanol formation and further derivation.
[0005] One of the most commonly used methods for degradation of the lignocellulose is heating of the wet biomass in the presence of an acid. Two major problems occur with such a treatment: 1) the heating may only be short, because otherwise too many unwanted byproducts are formed from the carbohydrates; and 2) it is difficult to produce a biomass slurry with more than 30% w/w solids, which is necessary for an economic use in further processing.
[0006] Accordingly there is still need for an efficient process in which lignocellulose is degraded to disclose the components thereof for further processing.
SUMMARY OF THE INVENTION
[0007] The present invention now overcomes the disadvantages of the prior art. Accordingly, the invention relates to a method for processing biomass derived from plants or animals, comprising the steps of:
[0008] a. pre treating said material with an aqueous solution of acid or base;
[0009] b. subsequently passaging saturated or super heated steam through said material,
[0000] whereby the water activity of the process is controlled by means of temperature and pressure of the super heated steam to be less than 1, preferably less than 0.8, more preferably between 0.4-0.8.
[0010] In a preferred embodiment, the acid is sulphuric acid (H 2 SO 4 ) or the base is chosen from the group consisting of calcium hydroxide, sodium hydroxide and potassium hydroxide, ammonium hydroxide or the acid or base is any in situ formed acid or base. Preferably the acid is provided in a solution of about 0.1% to about 4.0%, preferably about 0.5% to about 3.0%, more preferably about 2%. When a base is used, preferably the base is mixed with biomass in a ratio of 0.02 to 0.2 grams base per gram biomass dry matter, preferably in a ratio of 0.15.
[0011] In yet another preferred embodiment step a) is performed at a temperature of about 20 to about 80° C., more preferably at a temperature of about 50 to about 65° C. Further preferred is a method according to the invention, wherein the super heated steam is applied under a pressure between 1 and 10 bara, preferably between 4 and 8 bara, more preferably around 6 bara. Further preferred is a method according to the invention, wherein the temperature of the super heated steam is between 150 and 220° C., preferably between 160 and 200° C., more preferably between 170 and 180° C.
[0012] In yet another preferred embodiment the method according to the invenion comprises a further step c) of further enzymatic hydrolysis (exo and endo activity), oxidation, etherification or esterification of said material after SHS treatment.
[0013] Further preferred in a method according to the invention the biomass material is woody plant material, including leaves, twigs, bark, grasses, hay, reeds, megasse, straw, wood chips, sawdust, bagasse, corn stover, corn cobs, wheat bran, sugar beet press cake, rice hulls, palm, coconut, cotton fibres and/or peat, sphagnum, filtercake from sewage plants, sewage effluents, animal waste, like feathers and hairs, or crystalline cellulose.
LEGENDS TO THE FIGURES
[0014] FIG. 1 Temperature profile during small scale experiments (different loadings).
[0015] FIG. 2 Glucose recovery after SHS treatment where the treatment conditions are represented by the Combined Severity Factor (for explanation, see text).
[0016] FIG. 3 Temperature profile during scaling-up experiments (different loadings).
DEFINITIONS
[0017] “Lignocellulosic biomass” refers to plant biomass that is composed of cellulose, hemicellulose, and lignin.
[0018] “Super Heated Steam” (SHS) is steam that is (indirectly) heated to a temperature above its evaporation temperature. When water is heated it evaporates to steam at the boiling temperature of water to form steam. For example at atmospheric pressure the boiling temperature of water is 100° C.; for higher pressures the boiling temperature increases. This steam is still at the boiling temperature and it is called saturated steam. When saturated steam cools down it immediately condenses to water.
[0019] When however this saturated steam is heated, the temperature increases while the pressure stays the same. This is called Super Heated Steam, SHS, or dry steam. This SHS can cool down without immediate condensation. Only when the SHS is cooled down until the boiling temperature of water at the given pressure, it will start to condense.
[0020] The “water activity” or “Aw” of SHS as a processing medium can be controlled by varying the pressure and the superheating temperature. The Aw of SHS is the defined as the actual absolute pressure of the SHS divided by the pressure that saturated steam would have at that actual temperature of the SHS.
[0021] In formula:
[0000]
A
w
=P
SHS
/P
saturated steam at T SHS
[0022] (P=absolute pressure)
[0023] Some examples:
[0000]
Absolute pressure
Absolute pressure
Temperature
saturated steam at
SHS (bar)
SHS (° C.)
temperature SHS (bar)
Aw
1
120
2
1/2 = 0.50
1
144
4
1/4 = 0.25
1
159
6
1/6 = 0.17
1
180
10
1/10 = 0.10
2
144
4
2/4 = 0.50
2
159
6
2/6 = 0.33
2
180
10
2/10 = 0.2
4
159
6
4/6 = 0.67
4
180
10
4/10 = 0.40
6
180
10
6/10 = 0.60
[0024] This makes SHS unique over hot air, where the Aw value is always very low, normally below 0.01
[0025] “Treatment severity” is defined as the extent in which reactive and destructive conditions are present.
[0026] The “combined severity factor” or “CSF” describes the severity of various acid-catalyzed pretreatments by combining time, temperature and acid concentration. The combined severity factor (CSF) is given by:
[0000] CSF= log 10 {t r ·exp[( T r −100) 114.75]}−pH
[0027] in which T r is the reaction temperature in degrees Celsius and t r is the reaction time in minutes. The pH value is calculated from the sulphuric acid concentration inside the fibers at the beginning of the treatment (pre-impregnated material).
DETAILED DESCRIPTION
[0028] Heating a lignocellulose slurry to degrade it and make the individual components available for further processing has been performed in several ways in the prior art. Consequently, methods of applying heat to the material with super heated steam (SHS) have been known for a long time. As a matter of fact, one of the earliest disclosures of such a method is GB 127,388 from 1918 (!), in which a process is described for making fodder from e.g. peat moss or sphagnum, which involves an acid treatment of the biomaterial in an autoclave at relatively low pressure while heating (drying) with SHS. The main difference between this publication and the present invention is the fact that in GB 127,388 no pretreatment with acid is performed and that the steam is applied in a closed vessel and not in a system in which the steam is led through the material.
[0029] A drying action of SHS similar to the one used in the present invention is also described in GB 541,960. However, in this document no acid treatment is used to disintegrate the biomaterial, but instead the material is soaked with (normal, saturated) steam under high pressure. A similar system is described in U.S. Pat. No. 5,328,562 in which a two stage process of first heating the wet biomaterial under pressure followed by drying with SHS is used to produce hydrolysed biomaterial. It appears that hydrolysis is meant to take place without addition of any chemicals.
[0030] Another treatment with SHS is described in GB 491,842, but here the biomaterial is (pre)treated with (caustic) soda and not with acid.
[0031] A process which resembles the process of the invention is described in GB 349,032 wherein wood chips are impregnated with sulphuric acid and then subjected to SHS treatment. The main difference is that this process basically starts from cellulose and not lignocellulose, which implies that the goal of the treatment is not degradation of lignocellulose and disclosure of the components thereof, but reaction of cellulose into sugars. The acid pretreatment is effected with a large volume of a dilute (0.25−1%) acid solution, after which the bulk of the acid solution is removed and the reaction is continued for several hours under elevated pressure at a temperature of about 150° C. which is maintained by passing SHS through the material. Thus, although similar steps are applied in this process, the goal is different and differences in the process temperature and duration are apparent and explainable for this different goal.
[0032] A further prior art document is US 2003/199049 (patented as U.S. Pat. No. 6,660,506). This document describes a process in which biomass is impregnated with acid and wherein said biomass is dried with e.g. SHS, after which a heated hydrolysis takes place. The difference between the process as described in this document with the current invention is that the steps of drying and hydrolysis in the current invention take place simultaneously in one and the same reactor. The combination of these steps gives the advantage of a gradual increase in temperature which causes first the hemicellulose to be degraded and then the cellulose to decrystallize.
[0033] There are many prior art documents that apply steam at high temperature to a biomass, which is either pre-treated or not, but just application of the SHS only influences the surface of the biomass that is contacted. In the present invention the effect of the SHS is increased by the fact that the SHS is passaged through the biomass, meaning that the effect of the SHS treatment also is provided within the biomass. The effect is of course even more increased if the structure of the biomass is such that the SHS can easily reach the non-superficial parts. Thus a porous structure of the biomass or a very loose packing of the biomaterial greatly enhances the drying effect of the SHS.
[0034] Although the invention is mainly directed to biomass comprising lignocellulose, any biomass comprising lignocellulose, cellulose, hemi cellulose, lignin, proteins like chitin, keratin, carbohydrates like starches or the like and wherein the mentioned compounds need to be made more accessible for subsequent treatments may be processed.
[0035] According to the invention the lignocellulose containing material is impregnated with acid or base.
[0036] As acid or base in principle any inorganic or organic acid or base would be usable, but for economical reasons strong acids are preferred because even a diluted solution of such strong acids has sufficient hydrolytic action to be able to disclose the polysaccharides from the lignocellulose material. Further, since the acid treatment is preferably performed under an elevated temperature (from about 20° C. to about 200° C.) the acid solution should remain stable in this temperature range. Most preferably sulphuric acid is used. The acid is added to provide a final concentration of about 0.1% to 4% (but this can vary even further based on the particular acid used). For sulphuric acid preferably about 0.5% to about 3.0%, more preferably about 2% is used.
[0037] As base preferably a hydroxide is used, such as calcium hydroxide, sodium hydroxide or potassium hydroxide or ammonia hydroxide.
[0038] Further as acid or base any in situ formed acid (such as acetic acid) or base within the said process can be applicable.
[0039] Incubation of the biomaterial with the acid or base is performed for about 1 hour to about 24 hours. The optimal incubation time depends on the openness of the material: the more loosely the material is packed, the less incubation time is needed. For straw an optimal incubation time is approximately three hours. Wood will require longer incubation periods and these will depend on the size of the wood chips used.
[0040] Incubation with acid or base is also preferably performed at an elevated temperature. Generally the process will satisfactorily run at a temperature of about 20° C. to about 80° C., more preferably at a temperature of about 50° C. to about 65° C.
[0041] After incubation, the slurry consisting of the biomaterial and the acid or basic solution is then placed in a steam process or, more generally defined, in a surrounding, preferably a closed surrounding, in which super heated steam can be led through the biomass. The whole disintegration process with SHS is preferably performed under an increased pressure. During this disintegration process in SHS also drying takes place, thus resulting in a disintegrated biomass with a lower water content. It can be performed under atmospheric pressure (1 Bara) up to 10 Bara, but preferably is performed under a pressure of 2-7 Bara, more preferably 6 Bara.
[0042] Steam with a temperature of between about 150° C. and 220° C. (super heated steam, SHS) is produced and led through the chamber with the biomass. Preferably steam of about 170° C.-180° C. is used. As is the case with the acid incubation, also here the time that is needed to disintegrate the biomass with the SHS depends on the openness of the biomass: the less densely packed, the more opportunity there is for the steam to reach the surface of the biomass material, and the quicker the disintegration and drying process will occur. When the steam is applied, the biomass quickly warms up to the condensation temperature of the steam at the given pressure, for example at 6 bara at about 159° C. It will keep this temperature for a certain time as long as the surface of the biomass is still wet. When, due to the drying effect of SHS, the surface falls (locally) dry, the biomass will heat up further to a higher level. Application of steam is continued at this higher level for about 1 to 10 minutes, more preferably 1 to 5 minutes. After that, the application of steam is stopped, if necessary the pressure is returned to atmospheric pressure by opening the pressure chamber, and the biomass is allowed to cool down.
[0043] During the drying step of the process the Aw is preferably kept constant. This allows the application of higher temperatures (which, in turn, will result in a better liberation and hydrolysis) and also would allow for a minimalisation of the acid needed for the process. The Aw can easily be kept constant in SHS by keeping both the pressure and the SHS temperature constant. Preferably the Aw of the process is controlled by means of temperature and pressure of the super heated steam to be less than 1, preferably less than 0.8, more preferably in the range of 0.4-0.8.
[0044] During drying of the acid or base soaked biomass, the hydrolysis of the lignocellulose continues in a unique manner: because the acid or base concentration increases due to the evaporation of water and the temperature increases during this process, first the hemicellulose (which is located at the outside of the lignocellulose fibers) is—partially—degraded, then the bonds between lignin and polysaccharides are broken after which the remaining cellulose is decrystallized.
[0045] Thus, the above described process results in a biomass in which the polysaccharides are liberated from the lignocellulose complex and will be freely available for further hydrolysis, e.g. through addition of cellulose and/or lignin-degrading enzymes, or derivations or functionalization by means of acylation, oxidation, esterification, etherification, carboxymethylation and so on. In the Examples it is shown that because of the higher liberation rate of the polysaccharides, the yields of the further derivations/functionalizations is higher with a biomass preprocessed according to the invention.
[0046] Further, advantageously, it has appeared possible to reach higher dry solid weight contents (ranging from 25-65%) in the resulting biomass slurry, which makes it possible to feed subsequent fermentations with highly concentrated material and reach high titers of the desired fermentation product (e.g. in a fed batch simultaneous saccharification and fermentation process). This is also advantageous for the further processing, because less water has to be removed from the biomass slurry. It has further appeared that enzymatic hydrolysis after this new method for pretreatment of lignocellulose is very effective and yields of more than 90% conversion into glucose and xylose can be obtained. The obtained xylose can be reduced and used for the production of xylitol. Further, some byproducts that would hamper the further hydrolysis and fermentation, like furfural, HMF, acetic acid and levulinic acid are absent from or only present in low quantities in the resulting biomass slurry.
EXAMPLES
Example 1
Wheat Straw Biomass
[0047] Before superheated steam treatment the dried wheat straw (12 hrs 95° C.) was pre-impregnated in a H 2 SO 4 solution for 3 hours at 60° C. and 8% dry matter concentration to obtain the desired H 2 SO 4 concentration inside the fibres. After impregnation free liquid was removed by filtration.
[0048] All steam treatments were carried out at 6 bara in the TNO pilot laboratory super heated steam equipment. After inserting wheat straw into the steam equipment this pressure can immediately be reached. For exploring the effect of reaction conditions, different temperatures, sulphate concentrations and heating times were applied. The effect of the treatment on the accessibility of the polysaccharides was tested by enzymatic hydrolysis. To avoid product inhibition during the hydrolysis, the dry matter was diluted with water. This dilution was only carried out for determination purposes.
[0049] Samples of approximately 45 gram impregnated wheat straw were used (±10 gram dry matter). After steam drying water was added to the samples to obtain 5% dry matter concentrations. With calcium hydroxide the pH was adjusted to 5. Enzyme loading was 0.24 ml GC220 (a mixture of cellulose and hemicellulases from Genencor) and 0.018 ml NS50010 (cellobiase form Novozymes) per gram dry matter. 10 ml penstrep per liter hydrolysate was added and the enzymatic hydrolysis was performed for 3 days at 50° C.
[0050] For scaling-up two configurations were used. First a grid covered with a thick bed of wheat straw was used. Maximum load to cover the grid was 2000 gram impregnated wheat straw (±470 g dry matter). Then a rotating basket was used to mix the wheat straw arranging equal conditions for the complete sample. Maximum load was 1250 gram impregnated material (±250 g dry matter). Conditions found to be optimal during the small scale experiments were applied during scaling-up. After superheated steam treatment a small fraction of the wheat straw was used for hydrolysis. Hydrolysis was performed in the same way as described for the small scale experiments.
[0051] To determine efficiencies, glucose was measured via an enzymatic assay. Other monosaccharides and organic acids were measured with gas chromatography-mass spectrometry (GC-MS). HMF and furfural were measured with solid-phase microextraction (SPME).
1.1.1 Results Small Scale Experiments
[0052] To determine the temperature during superheated steam treatments the temperature inside the reactor was measured. An example is given in FIG. 1 .
[0053] During treatments the required temperature was reached after 30 seconds at about 160° C. The temperature in the reactor is depicted in FIG. 1 . The temperature inside the fibers can follow a different pattern; fast heating till 159° C. (boiling temperature at 6 bara) followed by evaporation of water and inherent increase of temperatures.
[0054] Table A gives the results for various SHS conditions, using previous experience gained with autoclave experiments. Sulphuric acid concentrations were comparable with dilute acid autoclave pretreatments (1.5-3% H 2 SO 4 ). The wheat straw samples contained approximately 20% dry matter after pre-impregnation. The glucose content of wheat straw used for these experiments was 0.343 g/g DM (determined with the method described by Cao et al., 1997), which was the theoretical maximum.
[0000]
TABLE A
Small scale SHS treatments, sulphate
concentrations between 1.5 and 3%
SHS conditions
After SHS treatment
Temp.
Time
H2SO4
H2SO4
Dry matter
Glucose yield
(° C.)
(min)
(%)
(%)
(%)
(g/g DM)
155
1.5
1.5
2.9
19
0.27
″
″
2.0
3.6
22
0.29
″
″
3.0
4.8
24
0.29
160
1
1.5
3.4
25
0.23
″
″
2.0
4.0
26
0.18
″
″
3.0
5.3
27
0.23
160
1.5
1.5
3.2
28
0.29
″
″
2.0
4.1
32
0.27
160
2.5
1.5
3.2
27
0.29
″
″
2.0
3.9
30
0.29
″
″
3.0
4.7
28
0.31
160
3.5
1.5
3.1
21
0.32
″
″
2.0
4.4
29
0.33
″
″
3.0
4.7
24
0.31
165
1
1.5
3.3
29
0.25
″
″
2.0
4.2
33
0.23
″
″
3.0
4.8
28
0.28
165
1.5
1.5
3.4
26
0.28
″
″
2.0
4.3
28
0.25
″
″
3.0
5.7
29
0.27
170
1
1.5
3.9
30
0.18
″
″
2.0
4.5
30
0.21
″
″
3.0
5.3
27
0.22
170
1.5
2.0
4.0
28
0.32
170
2.5
1.5
4.0
37
0.27
″
″
2.0
4.6
37
0.29
″
″
3.0
6.4
38
0.28
170
6.5
2.0
4.1
29
0.11
175
1.5
2.0
6.2
48
0.26
175
3.5
1.5
8.0
56
0.29
″
″
2.0
6.8
44
0.32
″
″
3.0
10.0
47
0.31
180
1.5
1.5
4.6
37
0.28
″
″
2.0
4.8
32
0.24
″
″
3.0
6.2
32
0.25
180
3.5
2.0
12.3
65
0.28
180
6.5
2.0
11.0
62
0.21
190
1
1.5
5.0
40
0.24
″
″
2.0
4.9
33
0.27
″
″
3.0
6.2
32
0.26
190
1.5
2.0
7.1
49
0.28
[0055] The water activities in this experiment ranged from 0.47 (at 190° C.) via 0,75 (at 170° C.) and 0,97 (at 160° C.) to 1.0 (at 155° C.), all at 6 bara pressure. After SHS treatment the dry matter concentration increased. Higher reaction temperatures gave more evaporation of water and higher sulphate and dry matter concentrations. Increasing dry matter concentration is advantageous for the economy of fermentation processes—increasing dry matter gives higher sugar and subsequently ethanol concentrations.
[0056] Temperatures ranging from 155 till 190° C. can be applied to obtain glucose yields above 0.28 g/g DM. Variation of the sulphate concentration (1.5 to 3%) or the reaction time (1.5 to 3.5 minutes) did not give large fluctuations in glucose yield. A wide range of severity parameters gains high yield and therefore the optimum is broad.
[0057] For some SHS treatments the yields for xylose, arabinose, HMF and furfural (inhibitors during fermentation) are determined. Table B gives these values.
[0000]
TABLE B
Yields for monosaccharides and inhibitors after SHS
SHS Conditions
Yields
Temp
Time
H2SO4
Glucose
Arabinose
Xylose
HMF*
furfural*
(° C.)
(min)
(%)
(g/g DS)
(g/g DS)
(g/g DS)
(g/g DS)
(g/g DS)
160
1.5
1.5
0.29
0.02
0.19
<0.001
<0.001
″
″
2.0
0.27
0.02
0.19
<0.001
<0.001
160
2.5
1.5
0.29
0.02
0.19
<0.001
<0.001
″
″
2.0
0.29
0.01
0.18
<0.001
<0.001
″
″
3.0
0.31
0.02
0.19
<0.001
<0.001
170
1.5
2.0
0.32
0.01
0.21
<0.001
<0.001
170
2.5
1.5
0.27
0.01
0.17
<0.001
<0.001
″
″
2.0
0.29
0.01
0.17
<0.001
<0.001
″
″
3.0
0.28
0.01
0.15
<0.001
<0.001
180
1.5
2.0
0.29
0.01
0.19
<0.001
<0.001
180
3.5
0.5
0.19
0.02
0.16
<0.001
<0.001
″
″
2.0
0.28
0.01
0.13
<0.001
<0.001
190
1.5
0.5
0.13
0.02
0.12
<0.001
<0.001
″
″
2.0
0.28
0.01
0.17
<0.001
<0.001
190
6.5
0.5
0.17
0.01
0.13
<0.001
<0.001
*Below 0.05 g/l
[0058] The xylose content of the wheat straw was 0.19 g/g DM (method according to Cao et al., 1997). Inherent with increasing glucose yields the xylose yield increased. Almost all the xylose was recovered during optimal SHS treatments. HMF and furfural were not found in the hydrolysates. These inhibitors are volatile components and they are probably evaporated during steam treatment. The removal of these inhibitors during SHS treatment was very advantageous for the fermentation.
[0059] The combined severity factor (CSF) describes the severity of various acid-catalyzed pretreatments by combining time, temperature and acid concentration (Bower et al., 2008). It is a factor that is used widely in the art. Too low values lead to incomplete pretreatment and too high values to production of furfural and HMF from monosaccharides. The combined severity factor is given by:
[0000] CSF= log 10 {t r ·exp[( T r −100)/14.75]}−pH
[0000] in which T r is the reaction temperature in degrees Celsius and t r is the reaction time in minutes. The pH value is calculated from the sulphuric acid concentration inside the fibers at the beginning of the treatment (pre-impregnated material).
[0060] FIG. 2 gives the glucose recovery after SHS treatment where the treatment conditions are represented by the CSF.
[0061] The glucose recovery appears to peak at a CSF between 1.5 and 2. This confirms that the optimal conditions can be found in a reasonable wide range of severity.
[0062] Besides the use of SHS for dilute acid pretreatment, SHS heating may also be interesting for thermal mild acid pretreatment. In this method lower amounts of acids are used, but longer reaction times.
[0063] Table C gives the results for optimizing SHS conditions while sulphuric acid concentrations were used comparable with thermal mild acid pretreatments (0.1-0.5% H 2 SO 4 ).
[0000]
TABLE C
Small scale SHS treatments, sulphate
concentrations between 0.1 and 0.5%
SHS conditions
After SHS treatment
Temp.
Time
H2SO4
H2SO4
Dry matter
Glucose yield
(° C.)
(min)
(%)
(%)
(%)
(g/g DM)
180
3.5
0.1
2.3
66
0.11
″
″
0.5
3.0
49
0.19
180
6.5
0.1
4.7
91
0.09
″
″
0.5
64.6
98
0.05
190
1.5
0.1
2.1
51
0.08
″
″
0.5
2.6
39
0.13
190
6.5
0.1
4.4
90
0.07
″
″
0.5
4.1
64
0.17
160
15.0
pH 2
—
20
0.23
160
30.0
pH 2
—
22
0.24
160->170 (*)
25.3
pH 2
—
40
0.20
(*) 15 min 160° C., 10 min 170° C.
[0064] Thermal mild acid pretreatments comprehend high temperature and long reaction times. As a result dry matter concentrations after SHS treatment were very high which is advantageous for fermentation. However, glucose recovery was not higher than 0.17 g/g DM (50% yield). Thermal mild acid pretreatments need reaction times of >15 minutes together with temperatures around 190° C. This combination of time and temperature gives drying of the material at 6 bara operating pressure (boiling point is 159° C.). Without the presence of water the heating has no effect and reaction times >6.5 minutes and temperatures >180° C. will not enhance glucose recovery anymore.
[0065] Longer reaction times are possible if the temperature is close to the boiling point at 6 bara. Therefore 160° C. was applied together with reaction times of 15 and 30 minutes. Instead of adding a certain sulphate amount, the pH value was set to 2 during pre-impregnation of wheat straw (approximately 0.1% H 2 SO 4 ). The longer reaction times gave higher glucose yield. If the temperature was raised to 170° C. after 15 minutes the yield decreased because of glucose degradation. Xylose recovery was very high (0.17 g/g DM) during heating for 15 and 30 minutes at 160° C. (not shown in the table). 15 minutes heating at 165° C. at pH of 1.5 (about 0.4% H 2 SO 4 ) gave, after enzymatic hydrolysis a glucose recovery of 0.33 g/g DM).
1.1.2 Results Scaling-Up SHS Treatment
[0066] The optimal conditions for the straw substrate seemed to be 160° C.-170° C., 2.0% H 2 SO 4 and 3.5 minutes (table B). Glucose recovery was 0.33 g/g DM which is an efficiency of 96%. These conditions were used for investigating scaling-up of the SHS pretreatment. Table D gives the results of the experiments.
[0000]
TABLE D
Scaling-up SHS treatment
SHS Conditions
After SHS treatment
Mass
Dry
Glucose
WS
Temp.
Time
H2SO4
matter
yield
Configuration
(g)
(° C.)
(min)
(%)
(%)
(g/g DS)
Grid
175
160
3.5
2
25.9
0.33
Grid
175
165
3.5
2
28.0
0.33
Grid
175
170
3.5
2
31.9
0.31
Grid
440
160
3.5
2
28.3
0.31
Rotating basket
258
160
3.5
2
23.5
0.33
Rotating basket
258
160
3.5
2
24.2
0.32
[0067] Covering the grid with 750 gram impregnated wheat straw (175 g dry matter) and no mixing gave the same efficiency (0.33 g/g DM) as reached in small scale experiments. More loading (440 g dry matter) slightly decreased the glucose recovery. Steam entered the wheat straw bed from above. While passing the bed the steam lost heat and the treatment severity decreased. A small sample placed in a basket below the wheat straw bed during treatment of the 440 g loading confirmed this. The glucose recovery for that sample was only 0.26 g/g DM.
[0068] A rotating basket was used to mix the wheat straw during heat treatment and achieve equal conditions for the complete sample. Maximal load was 1250 gram pre-impregnated wheat straw (260 gram dry matter) and glucose recovery was still 0.33 g/g DM. Xylose recovery was also high (0.18 g/g DM). The fermentation inhibitors were measured as well in the hydrolysate. It appeared that no HMF, furfural, levulinic acid and acetic acid were present. These components, coincidently the notorious top 4 fermentation inhibitors, are probably evaporated during SHS treatment.
[0069] FIG. 3 shows that the heating up period for large scale experiments were as short as the small scale experiments.
REFERENCES
[0070] Bower S, Wickramadinghe R, Nagle N J, Schell D J (2008) Modeling sucrose hydrolyses in dilute acid solutions at the pretreatement conditions for lignocellulosic biomass. Bioresource Technology 99:7354-7362
[0071] Cao B, Tschirner U, Ramaswamy, S, Webb A. 1997. A rapid modified gas chromatographic method for carbohydrate analysis of wood pulps. TAPPI Journal 80(9):193-197
Example 2
Chickenfeather Biomass
[0072] SHS treated chicken feathers. Several circumstances were applied as given in table 1.
[0073] Before the chicken feathers are treated with super heated steam the feathers are pretreated by soaking the feathers 3 hours at 50° C. in a 0.1 M sodium hydroxide solution. After the soaking the feathers were cooled down to room temperature and dried overnight.
[0000]
TABLE 1
Method
1
2
3
4
5
Pressure
4
2
3
5
5
Temperature (° C.)
160
120
143
160
160
Flow
160-180
160-180
160-180
160-180
160-180
Time (min)
10
10
10
10
5
Weight (g)
300
300
300
300
300
After drying (g)
270
300
290
275
250
Moisture (%)
69.9
65.2
69.0
65.2
63.4
[0074] Experiment 1
[0075] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 5 were added. The mixture is heated to 50 ° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0076] Experiment 2
[0077] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 5 were added. The mixture is heated to 70° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0078] Experiment 3
[0079] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 3 were added. The mixture is heated to 60° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0080] Experiment 4
[0081] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 2 were added. The mixture is heated to 70° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0082] Experiment 5
[0083] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 4 were added. The mixture is heated to 50° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0084] Experiment 6
[0085] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 1 were added. The mixture is heated to 50° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0086] Experiment 7
[0087] In 100 ml of water containing 2.5 g of calcium hydroxide 7.5 g (dry weight) of SHS treated chicken feathers according to method 5 were added. The mixture is heated to 80° C. After 7 hours the heating is switched of and the mixture is allowed to stir overnight. Then 30% hydrogen peroxide (5 ml) is added and the mixture is brought to pH 7 using dry ice, filtered and concentrated to 15 ml containing 50% dry weight protein.
[0088] Enzymatic hydrolysis of SHS treated chicken feathers
[0089] SHS treated chicken feathers, treated according to method 5 100 ml of water was added and the solution was brought to pH 9.2. Then the suspension was brought to 50° C. and 0.5 of a savinase solution was added. The pH was kept at 9.2 during the hydrolysis. After 2.5, 5, and 24 hours the hydrolysis was stopped by bringing the pH to neutral and the samples were filtered and the amount of feathers in grams was measured. In table 2 the results are given. As a blank experiment also feathers that were alkali treated but have not been put under SHS conditions was measured.
[0000]
TABLE 2
SHS treated
Alkaline
2.5 hours
5.7
9.7
5 hours
4.5
9.7
24 hours
3.2
6.6
Non enzymatic
10.0
treated feathers
Example 3
Derivation of Process Products
Example 3a
Acylation
[0090] (Pre)-treated straw was acetylated according to Rodrigues Filho et al. (2005).
[0091] The product data are summarised in Table 3.
[0092] Glacial acetic acid (40 mL) was added to (pre)-treated straw (2 g). The mixture was stirred during 30 minutes at room temperature. A solution of 0.3 mL H 2 SO 4 and 17.5 mL glacial acetic acid was added to the mix, after which it was stirred for 15 minutes at room temperature. The mixture was filtrated and the straw was returned into the initial flask. To the filtrate, 40 mL acetic anhydride was added. The acidic solution was mixed and added to the straw. The mixture was stirred for 30 minutes and left to stand for 1, 5 and 21 hours. Water (400 mL) was added and the solution was desalted using a membrane filter (MWCO 3500). Finally, the solution was freeze-dried and the product was analysed. The degree of substitution was determined by pretreating a sample by dissolving in water for free acid and in 0.5 M NaOH for total acid analysis. The sample was analysed using HPLC (column Aminex HPX-87H 300 mm×7.8 mm, eluent 0.01 M sulphuric acid, and RI detection).
[0000]
TABLE 3
Acetylated straw (degree of substitution—DS—per
anhydroglucose unit)
Straw
1 hour
5 hours
21 hours
Original
0.3
0.6
2.1
Pre-treated with 2% H2SO4
1.4
1.6
2.2
Pre-treated with 2% H2SO4 and SHS
1.8
1.8
2.2
Example 3b
Carboxymethylation
[0093] a. first step; pre-drying
[0094] Straw predried at 90° C. for 12 h
[0095] b. second step; sulfuric acid pre-treatment
[0096] To 10 liters of (2% (w/w) or pH 2), 900 g (dry solid) pre-dried straw is applied for 3 h at 60° C. Afterwards the straw is dried until a dry solid content of approximately 30%.
[0097] c. third step; SHS
[0098] A certain amount of sulfuric acid pre-treated straw is applied under superheated steam conditions for a certain amount of time and Temperature Table 4). Solid matter is approximately 20-25% after SHS
[0000]
TABLE 4
Concentration
Steam flow
P (atm)
Time (min)
Temp.
2%
180 kg/hr
6
3.5
160° C.
pH 2
180 kg/hr
6 (atm)
3.5
160° C.
Example 3b-2
Carboxymethylation: Impact Sulphuric Acid Treatment
[0099] A solution is prepared of 140 g isopropanol, 15.4 g water and 7.8 g NaOH (50%). To this, 32.5 g sulphuric acid pre-treated straw is added. Then 5.6 gr mono-chloric acetic acid is added. The mixture is stirred for 1 hour at 70C. The reaction is ended by addition of citric acid/ethanol until a pH is reached of approximately 7.
[0100] Then the mixture is centrifuged. To the residue demineralised water is added till a volume of 140 ml which is added to 420 ml ethanol (100%). The mixture is filtered over a Buchner funnel and washed with 100 ml water. Afterward the filtrate is dried at 60° C. in an oven till the moisture content is between 10-20%.
[0101] Swelling capacity was determined.
Example 3b-3
Carboxymethylation: Impact SHS+Water
[0102] A solution is prepared of 140 g isopropanol, 15.4 g water and 7.8 g NaOH (50%). To this, 32.5 g SHS (water) pre-treated straw is added. Then 5.6 g monochloric acetic acid is added. The mixture is stirred for 1 hour at 70° C. The reaction is ended by addition of citric acid/ethanol until a pH is reached of approximately 7.
[0103] Then the mixture is centrifuged. To the residue demineralised water is added till a volume of 140 ml which is added to 420 ml ethanol (100%). The mixture is filtered over a Buchner funnel and washed with 100 ml water. Afterward the filtrate is dried at 60° C. in an oven till moisture content between 10-20%.
[0104] Swelling capacity was determined.
Example 3b-4
Carboxymethylation: Impact Sulphuric Acid Treatment and SHS
[0105] A solution is prepared of 140g isopropanol, 15.4 g water and 7.8 g NaOH (50%). To this, 32.5 g sulphuric acid/SHS pre-treated straw is added. Then 5.6 g monochloric acetic acid is added. The mixture is stirred for 1 hour at 70C. The reaction is ended by addition of citric acid/ethanol until a pH is reached of approximately 7.
[0106] Then the mixture is centrifuged. To the residue, demineralised water is added till a volume of 140 ml which is added to 420 ml ethanol (100%). The mixture is filtered over a Buchner funnel and washed with 100 ml water. Afterward the filtrate is dried at 60° C. in an oven till dry solid content between 10-20%.
[0107] Swelling capacity was determined.
Example 3b-5
Carboxymethylation: Influence Degree of Substitution
[0108] A solution is prepared of 140 g isopropanol, 15.4 g water and 4 g NaOH (50%). To this, 21 g sulfuric acid/SHS pre-treated straw is added. Then 5.7 or 2.88 or 1.44 gr mono-chloric acetic acid is added. The mixture is stirred for 1 hour at 70C. The reaction is ended by addition of citric acid/ethanol until a pH is reached of approximately 7.
[0109] Then the mixture is centrifuged. To the residue, demineralised water is added till a volume of 140 ml which is added to 420 ml ethanol (100%). The mixture is filtered over a Buchner funnel and washed with 100 ml water. Afterward the filtrate is dried at 60C in an oven until a moisture content between 10-20%.
[0110] Swelling capacity was determined.
[0000]
TABLE 5
Result of experiments 3b-1 to 3b-5
Swelling capacity
sample
H 2 SO 4
SHS
ml/g
032
0
3.5 min
33
038-2
pH2
26
038-3
pH2
3.5 min
34
021
2%
—
10
022
2%
3.5 min
40
024
2%
3.5 min
34
Reaction
Swelling
Sample
Reaction T
time
capacity
swelling on
number
H 2 SO 4 %
SHS
70° C.
MCA•Na g
70° C.
ml/g
load
036
2
3.5 min
1 hour
5.76
20 h
50
6.6
037-1
2
3.5 min
1 hour
2.88
20 h
59
7.4
|
The invention is related to a method for processing biomass derived from plants or animals, comprising the steps of:
a. pre treating said material with an aqueous solution of acid or base;
b. subsequently passaging saturated or super heated steam through said material,
wherein the water activity of the process is controlled by means of temperature and pressure of the super heated steam to be less than 1, preferably less than 0.8, more preferably in the range of 0.4-0.8.
With such a process it is possible to disintegrate or make more accessible for subsequent treatments the lignocellulose from lignocellulose containing materials, like wood or other plant material, chitin from exoskeletons from Crustacea like crabs and shrimps, and proteins such as keratin from pig hair or chicken feather, for further derivation, like acylation, oxidation, etherification, carboxymethylation or esterification, or further enzymatic hydrolysis, and/or for production of chemicals, e.g. as sugars from carbohydrates for fermentation processes such as the production of (bio-) ethanolor as keratine hydrolysates for applications in paper or cosmetics.
| 3
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in International Patent Application No. PCT/DK2005/000175 filed on Mar. 15, 2005 and German Patent Application No. 10 2004 012 987.8 filed Mar. 16, 2004.
FIELD OF THE INVENTION
The invention concerns a method for the manufacturing of a fluid conduit, particularly a fluid conduit in a CO 2 refrigeration system.
BACKGROUND OF THE INVENTION
In many technical systems, for example refrigeration systems or hydraulic systems, a fluid under high pressure and/or under high temperature is transported. The conduits used for this purpose are usually made of metallic materials and have relatively large wall thicknesses. When at the same time flexible conduits are desired, for example in order to satisfy demands for vibration stability, these conduits are often wound around their longitudinal axis. Such wound conduits can, however, only be made with a limited cross-section. When a larger flow amount is required, the conduit is divided into a plurality of single pipes. The individually wound pipes are subsequently pushed into each other. This method is relatively expensive and requires narrow tolerances with regard to the pitch and the diameter of the windings.
A refrigeration system usually comprises several components. Some of these are a compressor, two heat exchangers and a valve. These components are connected to each other through conduits. Particularly with mobile applications, for example refrigeration systems, which are used for cooling in vehicles, these conduits must not only have corrosion stability and vibration stability, but also a certain flexibility. On the other hand, such a conduit must have a substantial pressure resistance, particularly when CO 2 (carbon dioxide) is used as refrigerant. This makes such conduits relatively expensive.
BRIEF SUMMARY OF THE INVENTION
The invention is based on the task of providing a fast and cost efficient method for the manufacturing of a fluid conduit.
According to the invention, this task is solved in that several pipes are simultaneously supplied by means of at least one roller, which is provided with peripheral grooves and are helically wound in a parallel direction with respect to each other, wherein each pipe is guided along a helical line, the helical lines of all pipes being parallel to each other.
With this embodiment, relatively thin pipes can be used. The effective cross-section of the fluid conduit then results from the sum of the cross-sections of all pipes. Pipes with a relatively small cross-section have a relatively high pressure resistance, that is, the costs to be spent on pressure resistance can be kept small. The helical line shaped arrangement of the individual pipes also provides a certain flexibility. The manufacturing becomes particularly cost effective by the fact that several pipes can be wound at the same time and in parallel. This practically automatically results in an arrangement of the pipes in such a manner that the pipes are located adjacently or at a predetermined distance to each other. Subsequent mounting of individual pipes in each other or adjustment can be avoided. With the winding of the pipes, a large share of the manufacturing process is finished. The method is in principle suited for the manufacturing of fluid conduits, for example for hydraulic or refrigeration systems. However, the method becomes a particular importance for systems working with a refrigerant being under a higher pressure, for example CO 2 (carbon dioxide). Here, the pipes are supplied over at least one roller, which is provided with peripheral grooves. With this roll, the desired lateral alignment of the pipes in relation to each other can be realised in a simple manner. When several rollers are used in this manner, the periphery of the individual windings of the helical line can help provide a relatively exact positioning of the individual pipes in relation to each other. As soon as the pipes have been bent over an initial angle of for example 10°, a guiding with rollers is no longer absolutely required, as, once formed, the windings will not unwind again by themselves.
It is preferred that after making the windings, the pipes are cut to length one by one, the bundle formed by the pipes being twisted by a predetermined angle between the individual cutting processes. Thus, it is considered that later, when all the windings have been finished, the individual pipes should all end at approximately the same axial position of the “screw”. A sequential cutting and twisting the pipe bundle ensures that the cutting process can always take place in the same spot. The correct length of the individual pipes will thus be achieved practically automatically. With this method, conduits can in principle be made continuously in desired and different lengths. The method is therefore excellently suited for mass production, however at the same time meets the requirements of a fast type shift.
Preferably, after winding, the ends of the pipes are bent over in parallel to the axis of the helical line. This makes it easier to mount a connection for the pipes. The subsequent mounting process is thus simplified.
Preferably, at least the helically shaped winding area of the conduit is embedded in a plastic material. Here, the term “plastic material” could also cover a rubber. The plastic material stabilises the “body” of the conduit, at the same time ensuring that the conduit has a certain flexibility. The plastic covering does not only provide a mechanical stabilisation. It also ensures an increased thermal resistance towards the environment, so that the heat losses can be kept small. Further, the embedding provides a corrosion protection for the pipes, particularly when used in aggressive environments.
Preferably, before the embedding, the ends of the pipes are twisted by a predetermined angle in relation to each other against the winding direction, are held in the twisted position during the embedding and are released after the embedding. For example, the ends can be twisted in relation to each other by approximately 10°. This gives small clearances between adjacent windings, where the plastic material can penetrate. The embedding with the plastic material can, for example, be made by means of an injection moulding process. The clearances between the windings filled by the plastic material prevent the pipes from touching each other. During operation of the refrigeration system, the pipes are prevented from hitting or rubbing on each other. Thus, undesired noises are prevented, and the risk of possibly occurring leakages caused by wear of the pipes in the contact points is reduced. When, after the injection moulding (or another embedding process), the ends are released, the windings of the helical axes of all pipes are under a certain pretension. This further contributes to an improvement of the stability of the conduit.
In a preferred embodiment, it is provided that during embedding of the conduit a core within the windings is kept free. This means that the plastic material has the shape of a hollow cylinder. The hollow inside saves weight. The fact that the inner space or the core is kept free improves the flexibility of the conduit. If desired, it will also be possible to guide additional devices, for example electrical cables or the like through the inside of the conduit.
Preferably, ends belonging together are provided with a common connecting piece. This simplifies the subsequent mounting of the conduit in a technical system, for example a refrigeration system.
It is preferred that the connecting piece is connected to the plastic material. This ensures improved pressure resistance over the whole length of the conduit. There is no position, in which shear forces could act upon the pipes. On a whole, this improves the stability of the conduit.
It is preferred that the connecting piece is pressed against and welded onto the plastic material. This gives a very stable connection between the connecting piece and the plastic material. After loosening the pressing force, a slightly increased pretension occurs in the axial direction of the helical line.
Preferably, the ends of the pipes are guided through the connecting piece and an occurring excess length is cut off. Thus, it is achieved that the pipe ends flush with the front face of the connecting piece. The guiding of the refrigerant is then exclusively handled by the pipes, which are preferably made of a suitable metal, for example, aluminium. The plastic material merely has supporting purposes.
It is preferred that the cutting is made by means of laser. The laser is able to cut off the excess lengths so that they flush with the front face of the connecting piece.
Preferably, at least one guide roller is provided, whose rotational axis encloses an acute angle in relation to the axis of the roller. The guide roller causes a lateral deflection movement of the supply pipes, thus controlling the pitch of the helical line.
Preferably, the pipes are guided towards a deflection face, the deflection face enclosing in a supply plane a first angle with the supply direction and a second angle with the supply plane. Thus, the pipes are deflected twice, firstly so as to bend over in the peripheral direction of the helical line, secondly so as to get an axial advance, which makes the helical line occur.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is described on the basis of preferred embodiments in connection with the drawings, showing:
FIG. 1 is a schematic view explaining the manufacturing of a fluid conduit;
FIG. 2 is an arrangement of pipes;
FIG. 3 is a top view according to FIG. 1 ;
FIG. 4 is a grooved guide roller;
FIG. 5 is a pipe after manufacturing of the helical line shaped windings;
FIG. 6 is the pipe according to FIG. 5 with aligned ends;
FIG. 7 is a connecting piece;
FIG. 8 is a second embodiment of a connecting piece;
FIG. 9 is a conduit with connecting pieces; and
FIG. 10 is a perspective view of a modified embodiment of a conduit.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 9 shows a conduit 1 with two connecting pieces 2 , 3 and a body 4 , whose manufacturing will be explained below.
The body 4 is formed by five pipes, shown in FIG. 1 in a side view, in FIG. 2 in a front view and in FIG. 3 in a top view. The wall thickness of these pipes 5 - 9 is shown in an enlarged view in FIG. 2 . The wall thickness must be so large that it can stand a pressure, which is generated in the hollow inner chamber 10 of each pipe 5 - 9 , when later the pipe 5 - 9 is used in a refrigeration system working with CO 2 (carbon dioxide) as refrigerant. Such pressures can easily have a magnitude of several 100 bar. However, pipes 5 - 9 with a smaller cross-section are comparatively more pressure resistant than pipes with a larger cross-section, but with the same wall thickness. The conduit 1 made in this manner can of course also be used with other refrigerants, also those working with smaller pressures.
As can be seen from the FIGS. 1 and 3 , the pipes 5 - 9 are guided over three guide rollers 11 - 13 in one plane to be adjacent to each other. All three guide rollers 11 - 13 have the same design. The guide roller 11 is shown in an enlarged view in FIG. 4 . It has five peripheral grooves 14 . The number of the peripheral grooves distributed evenly in the axial direction of the guide roller 11 of course depends on the number of pipes 5 - 9 to be wound simultaneously.
The two guide rollers 11 , 12 are shown to be stationary. The guide roller 13 is movable in the direction of a double arrow 15 , that is, perpendicularly to the plane, in which the pipes 5 - 9 are located during the supply.
Of course, the guide rollers 11 , 12 can also be movable, if this should be required for an insertion process.
The pipes 5 - 9 are supplied in a feed direction 16 . In this connection they can be unrolled from store spools, which are not shown in detail. Means, with which the feed is generated, are known per se and therefore not shown in detail. For example, roller pairs can be used, which act upon the pipes 5 - 9 from opposite sides, causing a drive on the pipes 5 - 9 by means of frictional force.
In the feed direction 16 behind the last guide roller 13 is located a deflection face 17 . The directional component shown in FIG. 1 of this deflection face 17 encloses an angle different from 90° with the plane, in which the pipes 5 - 9 are supplied. The deflection face 17 , or rather the recognisable component in FIG. 1 , causes together with the last guide roller 13 that the pipes are bent over to be annular, so that in the view in FIG. 1 the shape of the bend appears to be practically circular.
As can be seen from FIG. 3 , the deflection face 17 also encloses an angle different from 90° with the feed direction 16 , so that the supplied pipes 5 - 9 are not only deflected to a circular path, but also receive a deflection perpendicular to the feed direction 16 . Accordingly, the pipes 5 - 9 are guided on a helical line. To support this deflection movement, the last guide roller 13 can have a rotational axis in relation to the other guide rollers 11 , 12 , said rotational axis no longer being aligned in parallel with the axes of the guide rollers 11 , 12 , but enclosing an acute angle with them. Also the guide roller 12 can be located under an acute angle to the guide roller 11 to control the pitch of the helical line. The deflection face 17 serves the purpose of setting the pitch with a relatively large accuracy.
As can be seen from the FIGS. 3 and 5 , the pipes 5 - 9 are wound in the shape of a helical line, meaning that also during winding the parallel alignment of the pipes 5 - 9 in relation to each other is maintained. After the winding, the pipes 5 - 9 still bear on each other. The windings made in this manner form a hollow cylinder.
Now, the pipes 5 - 9 have ends, which project in an “inclined” manner from the body 4 . This means that they have a radial and an axial directional component. However, all of them have substantially the same length. This is achieved in that the individual pipes 5 - 9 are not cut off at the same time, when the body 4 has reached its desired length, but are cut off sequentially. This means that when reaching the desired length, firstly one pipe, for example the pipe 5 , is cut off, then the body 4 is further rotated, until the pipe 6 has reached the position of the previously cut off pipe 5 , and the pipe 6 is cut off. This process is repeated, that is, between the cuttings of the individual pipes 5 - 9 a rotation takes place by an angle, which corresponds to 360° divided by the number of pipes.
In a further manufacturing step, the ends 18 - 22 are now bent over and aligned in parallel with the axis of the body 4 . Then, it is possible to push the connecting piece 3 onto the ends 18 - 22 . For this purpose, the connecting piece 3 comprises a number of bores 23 , which corresponds to the number of pipes 5 - 9 .
FIG. 7 shows a first embodiment of a connecting piece 3 with a circular shape. FIG. 8 shows a modified embodiment of a connecting piece 3 ′ with a hexagon shape, as side view in FIG. 8 a and as front view in FIG. 8 b . The shape of the connecting piece 3 , 3 ′ depends on the desired application.
Before or after mounting of the connecting piece 3 , the body 4 is provided with a plastic material 24 as shown in FIG. 9 . The plastic material 24 could also be a natural rubber, which is used in a vulcanised form for this purpose. Expediently, the plastic material is manufactured in an injection moulding process. For this purpose, the body 4 is placed in an injection moulding die. Prior to that, however, the ends of the body are twisted in relation to each other against the winding direction. This is shown by means of the arrows 25 , 26 . The twisting angle is relatively small. It amounts to, for example, 10°. This results in a small clearance between adjacent windings of the body 4 , into which the plastic material 24 can penetrate when injected. A core ensures that the hollow inside of the body 4 is not completely filled with plastic material 24 . On the contrary, a hollow cylinder remains. After the injection of the plastic material 24 , the tension, with which the ends of the body 4 have been twisted or “wound” in relation to each other, is released again, so that the wound pipes 5 - 9 to remain in the plastic material 24 with a certain pretension.
After embedding the body 4 in the plastic material, the two connecting pieces 2 , 3 are pressed against the plastic material 24 . This is indicated by means of arrows 27 , 28 . Of course, the corresponding forces are directed so that the connecting pieces 2 , 3 bear with their full face on the front side of the plastic material 24 . Then, the connecting pieces 2 , 3 are welded or glued onto the plastic material 24 , so that in total a practically monolithic block appears, in which a flow path for the carbon dioxide refrigerant is formed inside the pipes 5 - 9 bent in the shape of a helical line.
The ends 18 - 22 of the pipes 5 - 9 have such a length that, as shown with the connecting piece 3 , they can be guided through the connecting piece 3 and project slightly from the connecting piece 3 . This projection is cut off by means of a laser cutting device 29 . Thus, it is achieved that the ends 18 - 22 can be flushed with the front side of the connecting piece 3 .
Until now, the conduit 1 has been described with five pipes 5 - 9 . FIG. 10 shows a modified embodiment of a conduit 1 , in which a total of ten pipes are helically wound to create a connection between two connections 2 , 3 . The hollow chamber which forms inside the body 4 is shown by means of a circular cylinder 30 .
While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention.
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The invention relates to a method for producing a fluid conduit, in particular a fluid conduit for a CO 2 refrigerating plant. The aim of said invention is to develop a quick and inexpensive method. For this purpose, several pipes ( 5 - 9 ) are simultaneously supplied by means of at least one roller ( 11 ) which is provided with peripheral grooves ( 14 ) and are helically wound in a parallel direction with respect to each other, wherein each pipe ( 5 - 9 ) is guided along a helical line and the helical lines of all pipes ( 5 - 9 ) are parallel to each other.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent application Ser. No. 14/251,453, filed Apr. 11, 2014, which is a Continuation of U.S. patent application Ser. No. 14/035,561, filed Sep. 24, 2013, now U.S. Pat. No. 8,717,203, which is a Continuation of U.S. patent application Ser. No. 13/154,211, now U.S. Pat. No. 8,643,513, filed Jun. 6, 2011, which is a Continuation of U.S. patent application Ser. No. 12/703,042, filed Feb. 9, 2010, now U.S. Pat. No. 8,502,707, which is a Continuation of both U.S. patent application Ser. No. 11/651,366, filed Jan. 8, 2007, now abandoned, and U.S. patent application Ser. No. 11/651,365, filed Jan. 8, 2007, now U.S. Pat. No. 7,714,747. Each of application Ser. No. 11/651,366 and application Ser. No. 11/651,365 is a Continuation of U.S. patent application Ser. No. 10/668,768, filed Sep. 22, 2003, now U.S. Pat. No. 7,161,506, which is a Continuation of U.S. patent application Ser. No. 10/016,355, filed Oct. 29, 2001, now U.S. Pat. No. 6,624,761, which is a Continuation-In-Part of U.S. patent application Ser. No. 09/705,446, filed Nov. 3, 2000, now U.S. Pat. No. 6,309,424, which is a Continuation of U.S. patent application Ser. No. 09/210,491, filed Dec. 11, 1998, which is now U.S. Pat. No. 6,195,024. Each of the listed applications are incorporated herein by reference in their entireties.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates generally to a data compression and decompression and, more particularly, to systems and methods for data compression using content independent and content dependent data compression and decompression.
[0004] 2. Description of Related Art
[0005] Information may be represented in a variety of manners. Discrete information such as text and numbers are easily represented in digital data. This type of data representation is known as symbolic digital data. Symbolic digital data is thus an absolute representation of data such as a letter, figure, character, mark, machine code, or drawing.
[0006] Continuous information such as speech, music, audio, images and video, frequently exists in the natural world as analog information. As is well known to those skilled in the art, recent advances in very large scale integration (VLSI) digital computer technology have enabled both discrete and analog information to be represented with digital data. Continuous information represented as digital data is often referred to as diffuse data. Diffuse digital data is thus a representation of data that is of low information density and is typically not easily recognizable to humans in its native form.
[0007] There are many advantages associated with digital data representation. For instance, digital data is more readily processed, stored, and transmitted due to its inherently high noise immunity. In addition, the inclusion of redundancy in digital data representation enables error detection and/or correction. Error detection and/or correction capabilities are dependent upon the amount and type of data redundancy, available error detection and correction processing, and extent of data corruption.
[0008] One outcome of digital data representation is the continuing need for increased capacity in data processing, storage, and transmittal. This is especially true for diffuse data where increases in fidelity and resolution create exponentially greater quantities of data. Data compression is widely used to reduce the amount of data required to process, transmit, or store a given quantity of information. In general, there are two types of data compression techniques that may be utilized either separately or jointly to encode/decode data: lossless and lossy data compression.
[0009] Lossy data compression techniques provide for an inexact representation of the original uncompressed data such that the decoded (or reconstructed) data differs from the original unencoded/uncompressed data. Lossy data compression is also known as irreversible or noisy compression. Entropy is defined as the quantity of information in a given set of data. Thus, one obvious advantage of lossy data compression is that the compression ratios can be larger than the entropy limit, all at the expense of information content. Many lossy data compression techniques seek to exploit various traits within the human senses to eliminate otherwise imperceptible data. For example, lossy data compression of visual imagery might seek to delete information content in excess of the display resolution or contrast ratio.
[0010] On the other hand, lossless data compression techniques provide an exact representation of the original uncompressed data. Simply stated, the decoded (or reconstructed) data is identical to the original unencoded/uncompressed data. Lossless data compression is also known as reversible or noiseless compression. Thus, lossless data compression has, as its current limit, a minimum representation defined by the entropy of a given data set.
[0011] There are various problems associated with the use of lossless compression techniques. One fundamental problem encountered with most lossless data compression techniques are their content sensitive behavior. This is often referred to as data dependency. Data dependency implies that the compression ratio achieved is highly contingent upon the content of the data being compressed. For example, database files often have large unused fields and high data redundancies, offering the opportunity to losslessly compress data at ratios of 5 to 1 or more. In contrast, concise software programs have little to no data redundancy and, typically, will not losslessly compress better than 2 to 1.
[0012] Another problem with lossless compression is that there are significant variations in the compression ratio obtained when using a single lossless data compression technique for data streams having different data content and data size. This process is known as natural variation.
[0013] A further problem is that negative compression may occur when certain data compression techniques act upon many types of highly compressed data. Highly compressed data appears random and many data compression techniques will substantially expand, not compress this type of data.
[0014] For a given application, there are many factors that govern the applicability of various data compression techniques. These factors include compression ratio, encoding and decoding processing requirements, encoding and decoding time delays, compatibility with existing standards, and implementation complexity and cost, along with the is adaptability and robustness to variations in input data. A direct relationship exists in the current art between compression ratio and the amount and complexity of processing required. One of the limiting factors in most existing prior art lossless data compression techniques is the rate at which the encoding and decoding processes are performed. Hardware and software implementation tradeoffs are often dictated by encoder and decoder complexity along with cost.
[0015] Another problem associated with lossless compression methods is determining the optimal compression technique for a given set of input data and intended application. To combat this problem, there are many conventional content dependent techniques that may be utilized. For instance, file type descriptors are typically appended to file names to describe the application programs that normally act upon the data contained within the file. In this manner data types, data structures, and formats within a given file may be ascertained. Fundamental limitations with this content dependent technique include:
[0016] (1) the extremely large number of application programs, some of which do not possess published or documented file formats, data structures, or data type descriptors;
[0017] (2) the ability for any data compression supplier or consortium to acquire, store, and access the vast amounts of data required to identify known file descriptors and associated data types, data structures, and formats; and
[0018] (3) the rate at which new application programs are developed and the need to update file format data descriptions accordingly.
[0019] An alternative technique that approaches the problem of selecting an appropriate lossless data compression technique is disclosed, for example, in U.S. Pat. No. 5,467,087 to Chu entitled “High Speed Lossless Data Compression System” (“Chu”). FIG. 1 illustrates an embodiment of this data compression and decompression technique. Data compression 1 comprises two phases, a data pre-compression phase 2 and a data compression phase 3. Data decompression 4 of a compressed input data stream is also comprised of two phases, a data type retrieval phase 5 and a data decompression phase 6. During the data compression process 1, the data pre-compressor 2 accepts an uncompressed data stream, identifies the data type of the input stream, and generates a data type identification signal. The data compressor 3 selects a data compression method from a preselected set of methods to compress the input data stream, with the intention of producing the best available compression ratio for that particular data type.
[0020] There are several limitations associated with the Chu method. One such limitation is the need to unambiguously identify various data types. While these might include such common data types as ASCII, binary, or unicode, there, in fact, exists a broad universe of data types that fall outside the three most common data types. Examples of these alternate data types include: signed and unsigned integers of various lengths, differing types and precision of floating point numbers, pointers, other forms of character text, and a multitude of user defined data types. Additionally, data types may be interspersed or partially compressed, making data type recognition difficult and/or impractical. Another limitation is that given a known data type, or mix of data types within a specific set or subset of input data, it may be difficult and/or impractical to predict which data encoding technique yields the highest compression ratio.
[0021] Accordingly, there is a need for a data compression system and method that would address limitations in conventional data compression techniques as described above.
SUMMARY OF THE INVENTION
[0022] The present invention is directed to systems and methods for providing fast and efficient data compression using a combination of content independent data compression and content dependent data compression. In one aspect of the invention, a method for compressing data comprises the steps of:
[0023] analyzing a data block of an input data stream to identify a data type of the data block, the input data stream comprising a plurality of disparate data types;
[0024] performing content dependent data compression on the data block, if the data type of the data block is identified;
[0025] performing content independent data compression on the data block, if the data type of the data block is not identified.
[0026] In another aspect, the step of performing content independent data compression comprises: encoding the data block with a plurality of encoders to provide a plurality of encoded data blocks; determining a compression ratio obtained for each of the encoders; comparing each of the determined compression ratios with a first compression threshold; selecting for output the input data block and appending a null compression descriptor to the input data block, if all of the encoder compression ratios do not meet the first compression threshold; and selecting for output the encoded data block having the highest compression ratio and appending a corresponding compression type descriptor to the selected encoded data block, if at least one of the compression ratios meet the first compression threshold.
[0027] In another aspect, the step of performing content dependent compression comprises the steps of: selecting one or more encoders associated with the identified data type and encoding the data block with the selected encoders to provide a plurality of encoded data blocks; determining a compression ratio obtained for each of the selected encoders; comparing each of the determined compression ratios with a second compression threshold; selecting for output the input data block and appending a null compression descriptor to the input data block, if all of the encoder compression do not meet the second compression threshold; and selecting for output the encoded data block having the highest compression ratio and appending a corresponding compression type descriptor to the selected encoded data block, if at least one of the compression ratios meet the second compression threshold.
[0028] In yet another aspect, the step of performing content independent data compression on the data block, if the data type of the data block is not identified, comprises the steps of: estimating a desirability of using of one or more encoder types based one characteristics of the data block; and compressing the data block using one or more desirable encoders.
[0029] In another aspect, the step of performing content dependent data compression on the data block, if the data type of the data block is identified, comprises the steps of: estimating a desirability of using of one or more encoder types based on characteristics of the data block; and compressing the data block using one or more desirable encoders.
[0030] In another aspect, the step of analyzing the data block comprises analyzing the data block to recognize one of a data type, data structure, data block format, file substructure, and/or file types. A further step comprises maintaining an association between encoder types and data types, data structures, data block formats, file substructure, and/or file types.
[0031] In yet another aspect of the invention, a method for compressing data comprises the steps of:
[0032] analyzing a data block of an input data stream to identify a data type of the data block, the input data stream comprising a plurality of disparate data types;
[0033] performing content dependent data compression on the data block, if the data type of the data block is identified;
[0034] determining a compression ratio of the compressed data block obtained using the content dependent compression and comparing the compression ratio with a first compression threshold; and
[0035] performing content independent data compression on the data block, if the data type of the data block is not identified or if the compression ratio of the compressed data block obtained using the content dependent compression does not meet the first compression threshold.
[0036] Advantageously, the present invention employs a plurality of encoders applying a plurality of compression techniques on an input data stream so as to achieve maximum compression in accordance with the real-time or pseudo real-time data rate constraint. Thus, the output bit rate is not fixed and the amount, if any, of permissible data quality degradation is user or data specified.
[0037] These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a block/flow diagram of a content dependent high-speed lossless data compression and decompression system/method according to the prior art;
[0039] FIG. 2 is a block diagram of a content independent data compression system according to one embodiment of the present invention;
[0040] FIGS. 3 a and 3 b comprise a flow diagram of a data compression method according to one aspect of the present invention, which illustrates the operation of the data compression system of FIG. 2 ;
[0041] FIG. 4 is a block diagram of a content independent data compression system according to another embodiment of the present invention having an enhanced metric for selecting an optimal encoding technique;
[0042] FIGS. 5 a and 5 b comprise a flow diagram of a data compression method according to another aspect of the present invention, which illustrates the operation of the data compression system of FIG. 4 ;
[0043] FIG. 6 is a block diagram of a content independent data compression system according to another embodiment of the present invention having an a priori specified timer that provides real-time or pseudo real-time of output data;
[0044] FIGS. 7 a and 7 b comprise a flow diagram of a data compression method according to another aspect of the present invention, which illustrates the operation of the data compression system of FIG. 6 ;
[0045] FIG. 8 is a block diagram of a content independent data compression system according to another embodiment having an a priori specified timer that provides real-time or pseudo real-time of output data and an enhanced metric for selecting an optimal encoding technique;
[0046] FIG. 9 is a block diagram of a content independent data compression system according to another embodiment of the present invention having an encoding architecture comprising a plurality of sets of serially cascaded encoders;
[0047] FIGS. 10 a and 10 b comprise a flow diagram of a data compression method according to another aspect of the present invention, which illustrates the operation of the data compression system of FIG. 9 ;
[0048] FIG. 11 is block diagram of a content independent data decompression system according to one embodiment of the present invention;
[0049] FIG. 12 is a flow diagram of a data decompression method according to one aspect of the present invention, which illustrates the operation of the data compression system of FIG. 11 ;
[0050] FIGS. 13 a and 13 b comprise a block diagram of a data compression system comprising content dependent and content independent data compression, according to an embodiment of the present invention;
[0051] FIGS. 14 a - 14 d comprise a flow diagram of a data compression method using both content dependent and content independent data compression, according to one aspect of the present invention;
[0052] FIGS. 15 a and 15 b comprise a block diagram of a data compression system comprising content dependent and content independent data compression, according to another embodiment of the present invention;
[0053] FIGS. 16 a - 16 d comprise a flow diagram of a data compression method using both content dependent and content independent data compression, according to another aspect of the present invention;
[0054] FIGS. 17 a and 17 b comprise a block diagram of a data compression system comprising content dependent and content independent data compression, according to another embodiment of the present invention; and
[0055] FIGS. 18 a - 18 d comprise a flow diagram of a data compression method using both content dependent and content independent data compression, according to another aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0056] The present invention is directed to systems and methods for providing data compression and decompression using content independent and content dependent data compression and decompression. In the following description, it is to be understood that system elements having equivalent or similar functionality are designated with the same reference numerals in the Figures. It is to be further understood that the present invention may be implemented in various forms of hardware, software, firmware, or a combination thereof. In particular, the system modules described herein are preferably implemented in software as an application program that is executable by, e.g., a general purpose computer or any machine or device having any suitable and preferred microprocessor architecture. Preferably, the present invention is implemented on a computer platform including hardware such as one or more central processing units (CPU), a random access memory (RAM), and input/output (I/O) interface(s). The computer platform also includes an operating system and microinstruction code. The various processes and functions described herein may be either part of the microinstruction code or application programs which are executed via the operating system. In addition, various other peripheral devices may be connected to the computer platform such as an additional data storage device and a printing device.
[0057] It is to be further understood that, because some of the constituent system components described herein are preferably implemented as software modules, the actual system connections shown in the Figures may differ depending upon the manner in which the systems are programmed. It is to be appreciated that special purpose microprocessors may be employed to implement the present invention. Given the teachings herein, one of ordinary skill in the related art will be able to contemplate these and similar implementations or configurations of the present invention.
[0058] Referring now to FIG. 2 a block diagram illustrates a content independent data compression system according to one embodiment of the present invention. The data compression system includes a counter module 10 that receives as input an uncompressed or compressed data stream. It is to be understood that the system processes the input data stream in data blocks that may range in size from individual bits through complete files or collections of multiple files. Additionally, the data block size may be fixed or variable. The counter module 10 counts the size of each input data block (i.e., the data block size is counted in bits, bytes, words, any convenient data multiple or metric, or any combination thereof).
[0059] An input data buffer 20 , operatively connected to the counter module 10 , may be provided for buffering the input data stream in order to output an uncompressed data stream in the event that, as discussed in further detail below, every encoder fails to achieve a level of compression that exceeds an a priori specified minimum compression ratio threshold. It is to be understood that the input data buffer 20 is not required for implementing the present invention.
[0060] An encoder module 30 is operatively connected to the buffer 20 and comprises a set of encoders E1, E2, E3 . . . En. The encoder set E1, E2, E3 . . . En may include any number “n” of those lossless encoding techniques currently well known within the art such as run length, Huffman, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. It is to be understood that the encoding techniques are selected based upon their ability to effectively encode different types of input data. It is to be appreciated that a full complement of encoders are preferably selected to provide a broad coverage of existing and future data types.
[0061] The encoder module 30 successively receives as input each of the buffered input data blocks (or unbuffered input data blocks from the counter module 10 ). Data compression is performed by the encoder module 30 wherein each of the encoders E1 . . . En processes a given input data block and outputs a corresponding set of encoded data blocks. It is to be appreciated that the system affords a user the option to enable/disable any one or more of the encoders E1 . . . En prior to operation. As is understood by those skilled in the art, such feature allows the user to tailor the operation of the data compression system for specific applications. It is to be further appreciated that the is encoding process may be performed either in parallel or sequentially. In particular, the encoders E1 through En of encoder module 30 may operate in parallel (i.e., simultaneously processing a given input data block by utilizing task multiplexing on a single central processor, via dedicated hardware, by executing on a plurality of processor or dedicated hardware systems, or any combination thereof). In addition, encoders E1 through En may operate sequentially on a given unbuffered or buffered input data block. This process is intended to eliminate the complexity and additional processing overhead associated with multiplexing concurrent encoding techniques on a single central processor and/or dedicated hardware, set of central processors and/or dedicated hardware, or any achievable combination. It is to be further appreciated that encoders of the identical type may be applied in parallel to enhance encoding speed. For instance, encoder E1 may comprise two parallel Huffman encoders for parallel processing of an input data block.
[0062] A buffer/counter module 40 is operatively connected to the encoding module 30 for buffering and counting the size of each of the encoded data blocks output from encoder module 30 . Specifically, the buffer/counter 30 comprises a plurality of buffer/counters BC1, BC2, BC3 . . . BCn, each operatively associated with a corresponding one of the encoders E1 . . . En. A compression ratio module 50 , operatively connected to the output buffer/counter 40 , determines the compression ratio obtained for each of the enabled encoders E1 . . . En by taking the ratio of the size of the input data block to the size of the output data block stored in the corresponding buffer/counters BC1 . . . BCn. In addition, the compression ratio module 50 compares each compression ratio with an a priori-specified compression ratio threshold limit to determine if at least one of the encoded data blocks output from the enabled encoders E1 . . . En achieves a compression that exceeds an a priori-specified threshold. As is understood by those skilled in the art, the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. A description module 60 , operatively coupled to the compression ratio module 50 , appends a corresponding compression type descriptor to each encoded data block which is selected for output so as to indicate the type of compression format of the encoded data block.
[0063] The operation of the data compression system of FIG. 2 will now be discussed in is further detail with reference to the flow diagram of FIGS. 3 a and 3 b . A data stream comprising one or more data blocks is input into the data compression system and the first data block in the stream is received (step 300 ). As stated above, data compression is performed on a per data block basis. Accordingly, the first input data block in the input data stream is input into the counter module 10 that counts the size of the data block (step 302 ). The data block is then stored in the buffer 20 (step 304 ). The data block is then sent to the encoder module 30 and compressed by each (enabled) encoder E1 . . . En (step 306 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder E1 . . . En and maintained in a corresponding buffer (step 308 ), and the encoded data block size is counted (step 310 ).
[0064] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 ) to the size of each encoded data block output from the enabled encoders (step 312 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 314 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art.
[0065] After the compression ratios are compared with the threshold, a determination is s made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 316 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 316 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 318 ). A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 320 ).
[0066] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 316 ), then the encoded data block having the greatest compression ratio is selected (step 322 ). An appropriate data compression type descriptor is then appended (step 324 ). A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 326 ).
[0067] After the encoded data block or the unencoded data input data block is output (steps 326 and 320 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 328 ). If the input data stream includes additional data blocks (affirmative result in step 328 ), the next successive data block is received (step 330 ), its block size is counted (return to step 302 ) and the data compression process in repeated. This process is iterated for each data block in the input data stream. Once the final input data block is processed (negative result in step 328 ), data compression of the input data stream is finished (step 322 ).
[0068] Since a multitude of data types may be present within a given input data block, it is often difficult and/or impractical to predict the level of compression that will be achieved by a specific encoder. Consequently, by processing the input data blocks with a plurality of encoding techniques and comparing the compression results, content free data compression is advantageously achieved. It is to be appreciated that this approach is scalable through future generations of processors, dedicated hardware, and software. As processing capacity increases and costs reduce, the benefits provided by the present invention will continue to increase. It should again be noted that the present invention may employ any lossless data encoding technique.
[0069] Referring now to FIG. 4 , a block diagram illustrates a content independent data compression system according to another embodiment of the present invention. The data compression system depicted in FIG. 4 is similar to the data compression system of FIG. 2 except that the embodiment of FIG. 4 includes an enhanced metric functionality for selecting an optimal encoding technique. In particular, each of the encoders E1 . . . En in the encoder module 30 is tagged with a corresponding one of user-selected encoder desirability factors 70 . Encoder desirability is defined as an a priori user specified factor that takes into account any number of user considerations including, but not limited to, compatibility of the encoded data with existing standards, data error robustness, or any other aggregation of factors that the user wishes to consider for a particular application. Each encoded data block output from the encoder module 30 has a corresponding desirability factor appended thereto. A figure of merit module 80 , operatively coupled to the compression ratio module 50 and the descriptor module 60 , is provided for calculating a figure of merit for each of the encoded data blocks which possess a compression ratio greater than the compression ratio threshold limit. The figure of merit for each encoded data block is comprised of a weighted average of the a priori user specified threshold and the corresponding encoder desirability factor. As discussed below in further detail with reference to FIGS. 5 a and 5 b , the figure of merit substitutes the a priori user compression threshold limit for selecting and outputting encoded data blocks.
[0070] The operation of the data compression system of FIG. 4 will now be discussed in further detail with reference to the flow diagram of FIGS. 5 a and 5 b . A data stream comprising one or more data blocks is input into the data compression system and the first data block in the stream is received (step 500 ). The size of the first data block is then determined by the counter module 10 (step 502 ). The data block is then stored in the buffer 20 (step 504 ). The data block is then sent to the encoder module 30 and compressed by each (enabled) encoder in the encoder set E1 . . . En (step 506 ). Each encoded data block processed in the encoder module 30 is tagged with an encoder desirability factor that corresponds the particular encoding technique applied to the encoded data block (step 508 ). Upon completion of the encoding of the input data block, an encoded data block with its corresponding desirability factor is output from each (enabled) encoder E1 . . . En and maintained in a corresponding buffer (step 510 ), and the encoded data block size is counted (step 512 ).
[0071] Next, a compression ratio obtained by each enabled encoder is calculated by taking the ratio of the size of the input data block (as determined by the input counter 10 ) to the size of the encoded data block output from each enabled encoder (step 514 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 516 ). A determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 518 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 518 ), then the original unencoded input data block is selected for output and a null data compression type descriptor (as discussed above) is appended thereto (step 520 ). Accordingly, the original unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 522 ).
[0072] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 518 ), then a figure of merit is calculated for each encoded data block having a compression ratio which exceeds the compression ratio threshold limit (step 524 ). Again, the figure of merit for a given encoded data block is comprised of a weighted average of the a priori user specified threshold and the corresponding encoder desirability factor associated with the encoded data block. Next, the encoded data block having the greatest figure of merit is selected for output (step 526 ). An appropriate data compression type descriptor is then appended (step 528 ) to indicate the data encoding technique applied to the encoded data block. The encoded data block (which has the greatest figure of merit) along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 530 ).
[0073] After the encoded data block or the unencoded input data block is output (steps 530 and 522 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 532 ). If the input data stream includes additional data blocks (affirmative result in step 532 ), then the next successive data block is received (step 534 ), its block size is counted (return to step 502 ) and the data compression process is iterated for each successive data block in the input data stream. Once the final input data block is processed (negative result in step 532 ), data compression of the input data stream is finished (step 536 ).
[0074] Referring now to FIG. 6 , a block diagram illustrates a data compression system according to another embodiment of the present invention. The data compression system depicted in FIG. 6 is similar to the data compression system discussed in detail above with reference to FIG. 2 except that the embodiment of FIG. 6 includes an a priori specified timer that provides real-time or pseudo real-time output data. In particular, an interval timer 90 , operatively coupled to the encoder module 30 , is preloaded with a user specified time value. The role of the interval timer (as will be explained in greater detail below with reference to FIGS. 7 a and 7 b ) is to limit the processing time for each input data block processed by the encoder module 30 so as to ensure that the real-time, pseudo real-time, or other time critical nature of the data compression processes is preserved.
[0075] The operation of the data compression system of FIG. 6 will now be discussed in further detail with reference to the flow diagram of FIGS. 7 a and 7 b . A data stream comprising one or more data blocks is input into the data compression system and the first data block in the data stream is received (step 700 ), and its size is determined by the counter module 10 (step 702 ). The data block is then stored in buffer 20 (step 704 ).
[0076] Next, concurrent with the completion of the receipt and counting of the first data block, the interval timer 90 is initialized (step 706 ) and starts counting towards a user-specified time limit. The input data block is then sent to the encoder module 30 wherein data compression of the data block by each (enabled) encoder E1 . . . En commences (step 708 ). Next, a determination is made as to whether the user specified time expires before the completion of the encoding process (steps 710 and 712 ). If the encoding process is completed before or at the expiration of the timer, i.e., each encoder (E1 through En) completes its respective encoding process (negative result in step 710 and affirmative result in step 712 ), then an encoded data block is output from each (enabled) encoder E1 . . . En and maintained in a corresponding buffer (step 714 ).
[0077] On the other hand, if the timer expires (affirmative result in 710 ), the encoding process is halted (step 716 ). Then, encoded data blocks from only those enabled encoders E1 . . . En that have completed the encoding process are selected and maintained in buffers (step 718 ). It is to be appreciated that it is not necessary (or in some cases desirable) that some or all of the encoders complete the encoding process before the interval timer expires. Specifically, due to encoder data dependency and natural variation, it is possible that certain encoders may not operate quickly enough and, therefore, do not comply with the timing constraints of the end use. Accordingly, the time limit ensures that the real-time or pseudo real-time nature of the data encoding is preserved.
[0078] After the encoded data blocks are buffered (step 714 or 718 ), the size of each encoded data block is counted (step 720 ). Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 ) to the size of the encoded data block output from each enabled encoder (step 722 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 724 ). A determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 726 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 726 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 728 ). The original unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 730 ).
[0079] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 726 ), then the encoded data block having the greatest compression ratio is selected (step 732 ). An appropriate data compression type descriptor is then appended (step 734 ). The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 736 ).
[0080] After the encoded data block or the unencoded input data block is output (steps 730 or 736 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 738 ). If the input data stream includes additional data blocks (affirmative result in step 738 ), the next successive data block is received (step 740 ), its block size is counted (return to step 702 ) and the data compression process in repeated. This process is iterated for each data block in the input data stream, with each data block being processed within the user-specified time limit as discussed above. Once the final input data block is processed (negative result in step 738 ), data compression of the input data stream is complete (step 742 ).
[0081] Referring now to FIG. 8 , a block diagram illustrates a content independent data compression system according to another embodiment of the present system. The data compression system of FIG. 8 incorporates all of the features discussed above in connection with the system embodiments of FIGS. 2 , 4 , and 6 . For example, the system of FIG. 8 incorporates both the a priori specified timer for providing real-time or pseudo real-time of output data, as well as the enhanced metric for selecting an optimal encoding technique. Based on the foregoing discussion, the operation of the system of FIG. 8 is understood by those skilled in the art.
[0082] Referring now to FIG. 9 , a block diagram illustrates a data compression system according to a preferred embodiment of the present invention. The system of FIG. 9 contains many of the features of the previous embodiments discussed above. However, this embodiment advantageously includes a cascaded encoder module 30 c having an encoding architecture comprising a plurality of sets of serially cascaded encoders Em,n, where “m” refers to the encoding path (i.e., the encoder set) and where “n” refers to the number of encoders in the respective path. It is to be understood that each set of serially cascaded encoders can include any number of disparate and/or similar encoders (i.e., n can be any value for a given path m).
[0083] The system of FIG. 9 also includes a output buffer module 40 c which comprises a plurality of buffer/counters B/Cm,n, each associated with a corresponding one of the encoders Em,n. In this embodiment, an input data block is sequentially applied to successive encoders (encoder stages) in the encoder path so as to increase the data compression ratio. For example, the output data block from a first encoder E1,1, is buffered and counted in B/C1,1, for subsequent processing by a second encoder E1,2. Advantageously, these parallel sets of sequential encoders are applied to the input data stream to effect content free lossless data compression. This embodiment provides for multi-stage sequential encoding of data with the maximum number of encoding steps subject to the available real-time, pseudo real-time, or other timing constraints.
[0084] As with each previously discussed embodiment, the encoders Em,n may include those lossless encoding techniques currently well known within the art, including: run length, Huffman, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. Encoding techniques are selected based upon their ability to effectively encode different types of input data. A full complement of encoders provides for broad coverage of existing and future data types. The input data blocks may be applied simultaneously to the encoder paths (i.e., the encoder paths may operate in parallel, utilizing task multiplexing on a single central processor, or via dedicated hardware, or by executing on a plurality of processor or dedicated hardware systems, or any combination thereof). In addition, an input data block may be sequentially applied to the encoder paths. Moreover, each serially cascaded encoder path may comprise a fixed (predetermined) sequence of encoders or a random sequence of encoders. Advantageously, by simultaneously or sequentially processing input data blocks via a plurality of sets of serially cascaded encoders, content free data compression is achieved.
[0085] The operation of the data compression system of FIG. 9 will now be discussed in further detail with reference to the flow diagram of FIGS. 10 a and 10 b . A data stream comprising one or more data blocks is input into the data compression system and the first data block in the data stream is received (step 100 ), and its size is determined by the counter module 10 (step 102 ). The data block is then stored in buffer 20 (step 104 ).
[0086] Next, concurrent with the completion of the receipt and counting of the first data block, the interval timer 90 is initialized (step 106 ) and starts counting towards a user-specified time limit. The input data block is then sent to the cascade encoder module 30 C wherein the input data block is applied to the first encoder (i.e., first encoding stage) in each of the cascaded encoder paths E1,1 . . . Em,1 (step 108 ). Next, a determination is made as to whether the user specified time expires before the completion of the first stage encoding process (steps 110 and 112 ). If the first stage encoding process is completed before the expiration of the timer, i.e., each encoder (E1,1 . . . Em,1) completes its respective encoding process (negative result in step 110 and affirmative result in step 112 ), then an encoded data block is output from each encoder E1,1 . . . Em,1 and maintained in a corresponding buffer (step 114 ). Then for each cascade encoder path, the output of the completed encoding stage is applied to the next successive encoding stage in the cascade path (step 116 ). This process (steps 110 , 112 , 114 , and 116 ) is repeated until the earlier of the timer expiration (affirmative result in step 110 ) or the completion of encoding by each encoder stage in the serially cascaded paths, at which time the encoding process is halted (step 118 ).
[0087] Then, for each cascade encoder path, the buffered encoded data block output by the last encoder stage that completes the encoding process before the expiration of the timer is selected for further processing (step 120 ). Advantageously, the interim stages of the multi-stage data encoding process are preserved. For example, the results of encoder E1,1 are preserved even after encoder E1,2 begins encoding the output of encoder E1,1. If the interval timer expires after encoder E1,1 completes its respective encoding process but before encoder E1,2 completes its respective encoding process, the encoded data block from encoder E1,1 is complete and is utilized for calculating the compression ratio for the corresponding encoder path. The incomplete encoded data block from encoder E1,2 is either discarded or ignored.
[0088] It is to be appreciated that it is not necessary (or in some cases desirable) that some or all of the encoders in the cascade encoder paths complete the encoding process before the interval timer expires. Specifically, due to encoder data dependency, natural variation and the sequential application of the cascaded encoders, it is possible that certain encoders may not operate quickly enough and therefore do not comply with the timing constraints of the end use. Accordingly, the time limit ensures that the real-time or pseudo real-time nature of the data encoding is preserved.
[0089] After the encoded data blocks are selected (step 120 ), the size of each encoded data block is counted (step 122 ). Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 ) to the size of the encoded data block output from each encoder (step 124 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 126 ). A determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 128 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 128 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 130 ). The original unencoded data block and its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 132 ).
[0090] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 128 ), then a figure of merit is calculated for each encoded data block having a compression ratio which exceeds the compression ratio threshold limit (step 134 ). Again, the figure of merit for a given encoded data block is comprised of a weighted average of the a priori user specified threshold and the corresponding encoder desirability factor associated with the encoded data block. Next, the encoded data block having the greatest figure of merit is selected (step 136 ). An appropriate data compression type descriptor is then appended (step 138 ) to indicate the data encoding technique applied to the encoded data block. For instance, the data type compression descriptor can indicate that the encoded data block was processed by either a single encoding type, a plurality of sequential encoding types, and a plurality of random encoding types. The encoded data block (which has the greatest figure of merit) along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 140 ).
[0091] After the unencoded data block or the encoded data input data block is output (steps 132 and 140 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 142 ). If the input data stream includes additional data blocks (affirmative result in step 142 ), then the next successive data block is received (step 144 ), its block size is counted (return to step 102 ) and the data compression process is iterated for each successive data block in the input data stream. Once the final input data block is processed (negative result in step 142 ), data compression of the input data stream is finished (step 146 ).
[0092] Referring now to FIG. 11 , a block diagram illustrates a data decompression system according to one embodiment of the present invention. The data decompression system preferably includes an input buffer 1100 that receives as input an uncompressed or compressed data stream comprising one or more data blocks. The data blocks may range in size from individual bits through complete files or collections of multiple files. Additionally, the data block size may be fixed or variable. The input data buffer 1100 is preferably included (not required) to provide storage of input data for various hardware implementations. A descriptor extraction module 1102 receives the buffered (or unbuffered) input data block and then parses, lexically, syntactically, or otherwise analyzes the input data block using methods known by those skilled in the art to extract the data compression type descriptor associated with the data block. The data compression type descriptor may possess values corresponding to null (no encoding applied), a single applied encoding technique, or multiple encoding techniques applied in a specific or random order (in accordance with the data compression system embodiments and methods discussed above).
[0093] A decoder module 1104 includes a plurality of decoders D1 . . . Dn for decoding the input data block using a decoder, set of decoders, or a sequential set of decoders corresponding to the extracted compression type descriptor. The decoders D1 . . . Dn may include those lossless encoding techniques currently well known within the art, including: run length, Huffman, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. Decoding techniques are selected based upon their ability to effectively decode the various different types of encoded input data generated by the data compression systems described above or originating from any other desired source. As with the data compression systems discussed above, the decoder module 1104 may include multiple decoders of the same type applied in parallel so as to reduce the data decoding time.
[0094] The data decompression system also includes an output data buffer 1106 for buffering the decoded data block output from the decoder module 1104 .
[0095] The operation of the data decompression system of FIG. 11 will be discussed in further detail with reference to the flow diagram of FIG. 12 . A data stream comprising one or more data blocks of compressed or uncompressed data is input into the data decompression system and the first data block in the stream is received (step 1200 ) and maintained in the buffer (step 1202 ). As with the data compression systems discussed above, data decompression is performed on a per data block basis. The data compression type descriptor is then extracted from the input data block (step 1204 ). A determination is then made as to whether the data compression type descriptor is null (step 1206 ). If the data compression type descriptor is determined to be null (affirmative result in step 1206 ), then no decoding is applied to the input data block and the original undecoded data block is output (or maintained in the output buffer) (step 1208 ).
[0096] On the other hand, if the data compression type descriptor is determined to be any value other than null (negative result in step 1206 ), the corresponding decoder or decoders are then selected (step 1210 ) from the available set of decoders D1 . . . Dn in the decoding module 1104 . It is to be understood that the data compression type descriptor may mandate the application of: a single specific decoder, an ordered sequence of specific decoders, a random order of specific decoders, a class or family of decoders, a mandatory or optional application of parallel decoders, or any combination or permutation thereof. The input data block is then decoded using the selected decoders (step 1212 ), and output (or maintained in the output buffer 1106 ) for subsequent data processing, storage, or transmittal (step 1214 ). A determination is then made as to whether the input data stream contains additional data blocks to be processed (step 1216 ). If the input data stream includes additional data blocks (affirmative result in step 1216 ), the next successive data block is received (step 1220 ), and buffered (return to step 1202 ). Thereafter, the data decompression process is iterated for each data block in the input data stream. Once the final input data block is processed (negative result in step 1216 ), data decompression of the input data stream is finished (step 1218 ).
[0097] In other embodiments of the present invention described below, data compression is achieved using a combination of content dependent data compression and content independent data compression. For example, FIGS. 13 a and 13 b are block diagrams illustrating a data compression system employing both content independent and content dependent data compression according to one embodiment of the present invention, wherein content independent data compression is applied to a data block when the content of the data block cannot be identified or is not associable with a specific data compression algorithm. The data compression system comprises a counter module 10 that receives as input an uncompressed or compressed data stream. It is to be understood that the system processes the input data stream in data blocks that may range in size from individual bits through complete files or collections of multiple files. Additionally, the data block size may be fixed or variable. The counter module 10 counts the size of each input data block (i.e., the data block size is counted in bits, bytes, words, any convenient data multiple or metric, or any combination thereof).
[0098] An input data buffer 20 , operatively connected to the counter module 10 , may be provided for buffering the input data stream in order to output an uncompressed data stream in the event that, as discussed in further detail below, every encoder fails to achieve a level of compression that exceeds a priori specified content independent or content dependent minimum compression ratio thresholds. It is to be understood that the input data buffer 20 is not required for implementing the present invention.
[0099] A content dependent data recognition module 1300 analyzes the incoming data stream to recognize data types, data structures, data block formats, file substructures, file types, and/or any other parameters that may be indicative of either the data type/content of a given data block or the appropriate data compression algorithm or algorithms (in serial or in parallel) to be applied. Optionally, a data file recognition list(s) or algorithm(s) 1310 module may be employed to hold and/or determine associations between recognized data parameters and appropriate algorithms. Each data block that is recognized by the content data compression module 1300 is routed to a content dependent encoder module 1320 , if not the data is routed to the content independent encoder module 30 .
[0100] A content dependent encoder module 1320 is operatively connected to the content dependent data recognition module 1300 and comprises a set of encoders D1, D2, D3 . . . Dm. The encoder set D1, D2, D3 . . . Dm may include any number “n” of those lossless or lossy encoding techniques currently well known within the art such as MPEG4, various voice codecs, MPEG3, AC3, AAC, as well as lossless algorithms such as run length, Huffinan, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. It is to be understood that the encoding techniques are selected based upon their ability to effectively encode different types of input data. It is to be appreciated that a full complement of encoders and or codecs are preferably selected to provide a broad coverage of existing and future data types.
[0101] The content independent encoder module 30 , which is operatively connected to the content dependent data recognition module 1300 , comprises a set of encoders E1, E2, E3 . . . En. The encoder set E1, E2, E3 . . . En may include any number “n” of those lossless encoding techniques currently well known within the art such as run length, Huffman, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. Again, it is to be understood that the encoding techniques are selected based upon their ability to effectively encode different types of input data. It is to be appreciated that a full complement of encoders are preferably selected to provide a broad coverage of existing and future data types.
[0102] The encoder modules (content dependent 1320 and content independent 30 ) selectively receive the buffered input data blocks (or unbuffered input data blocks from the counter module 10 ) from module 1300 based on the results of recognition. Data compression is performed by the respective encoder modules wherein some or all of the encoders D1 . . . Dm or E1 . . . En processes a given input data block and outputs a corresponding set of encoded data blocks. It is to be appreciated that the system affords a user the option to enable/disable any one or more of the encoders D1 . . . Dm and E1 . . . En prior to operation. As is understood by those skilled in the art, such feature allows the user to tailor the operation of the data compression system for specific applications. It is to be further appreciated that the encoding process may be performed either in parallel or sequentially. In particular, the encoder set D1 through Dm of encoder module 1320 and/or the encoder set E1 through En of encoder module 30 may operate in parallel (i.e., simultaneously processing a given input data block by utilizing task multiplexing on a single central processor, via dedicated hardware, by executing on a plurality of processor or dedicated hardware systems, or any combination thereof). In addition, encoders D1 through Dm and E1 through En may operate sequentially on a given unbuffered or buffered input data block. This process is intended to eliminate the complexity and additional processing overhead associated with multiplexing concurrent encoding techniques on a single central processor and/or dedicated hardware, set of central processors and/or dedicated hardware, or any achievable combination. It is to be further appreciated that encoders of the identical type may be applied in parallel to enhance encoding speed. For instance, encoder E1 may comprise two parallel Huffman encoders for parallel processing of an input data block. It should be further noted that one or more algorithms may be implemented in dedicated hardware such as an MPEG4 or MP3 encoding integrated circuit.
[0103] Buffer/counter modules 1330 and 40 are operatively connected to their respective encoding modules 1320 and 30 , for buffering and counting the size of each of the encoded data blocks output from the respective encoder modules. Specifically, the content dependent buffer/counter 1330 comprises a plurality of buffer/counters BCD1, BCD2, BCD3 . . . BCDm, each operatively associated with a corresponding one of the encoders D1 . . . Dm. Similarly the content independent buffer/counters BCE1, BCE2, BCE3 . . . BCEn, each operatively associated with a corresponding one of the encoders E1 . . . En. A compression ratio module 1340 , operatively connected to the content dependent output buffer/counters 1330 and content independent buffer/counters 40 determines the compression ratio obtained for each of the enabled encoders D1 . . . Dm and or E1 . . . En by taking the ratio of the size of the input data block to the size of the output data block stored in the corresponding buffer/counters BCD1, BCD2, BCD3 . . . BCDm and or BCE1, BCE2, BCE3 . . . BCEn. In addition, the compression ratio module 1340 compares each compression ratio with an a priori-specified compression ratio threshold limit to determine if at least one of the encoded data blocks output from the enabled encoders BCD1, BCD2, BCD3 . . . BCDm and or BCE1, BCE2, BCE3 . . . BCEn achieves a compression that meets an a priori-specified threshold. As is. understood by those skilled in the art, the threshold limit maybe specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It should be noted that different threshold values may be applied to content dependent and content independent encoded data. Further these thresholds may be adaptively modified based upon enabled encoders in either or both the content dependent or content independent encoder sets, along with any associated parameters. A compression type description module 1350 , operatively coupled to the compression ratio module 1340 , appends a corresponding compression type descriptor to each encoded data block which is selected for output so as to indicate the type of compression format of the encoded data block.
[0104] A mode of operation of the data compression system of FIGS. 13 a and 13 b will now be discussed with reference to the flow diagrams of FIGS. 14 a - 14 d , which illustrates a method for performing data compression using a combination of content dependent and content independent data compression. In general, content independent data compression is applied to a given data block when the content of a data block cannot be identified or is not associated with a specific data compression algorithm. More specifically, referring to FIG. 14 a , a data stream comprising one or more data blocks is input into the data compression system and the first data block in the stream is received (step 1400 ). As stated above, data compression is performed on a per data block basis. As previously stated a data block may represent any quantity of data from a single bit through a multiplicity of files or packets and may vary from block to block. Accordingly, the first input data block in the input data stream is input into the counter module 10 that counts the size of the data block (step 1402 ). The data block is then stored in the buffer 20 (step 1404 ). The data block is then analyzed on a per block or multi-block basis by the content dependent data recognition module 1300 (step 1406 ). If the data stream content is not recognized utilizing the recognition list(s) or algorithms(s) module 1310 (step 1408 ) the data is routed to the content independent encoder module 30 and compressed by each (enabled) encoder E1 . . . En (step 1410 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder E1 . . . En and maintained in a corresponding buffer (step 1412 ), and the encoded data block size is counted (step 1414 ).
[0105] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 to the size of each encoded data block output from the enabled encoders (step 1416 ). Each compression ratio is then compared with an apriori-specified compression ratio threshold (step 1418 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art. Additionally the content independent data compression threshold may be different from the content dependent threshold and either may be modified by the specific enabled encoders.
[0106] After the compression ratios are compared with the threshold, a determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 1420 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 1420 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 1434 ). A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1436 ).
[0107] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 1420 ), then the encoded data block having the greatest compression ratio is selected (step 1422 ). An appropriate data compression type descriptor is then appended (step 1424 ). A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1426 ).
[0108] As previously stated the data block stored in the buffer 20 (step 1404 ) is analyzed on a per block or multi-block basis by the content dependent data recognition module 1300 (step 1406 ). If the data stream content is recognized utilizing the recognition list(s) or algorithms(s) module 1310 (step 1434 ) the appropriate content dependent algorithms are enabled and initialized (step 1436 ), and the data is routed to the content dependent encoder module 1320 and compressed by each (enabled) encoder D1 . . . Dm (step 1438 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder D1 . . . Dm and maintained in a corresponding buffer (step 1440 ), and the encoded data block size is counted (step 1442 ).
[0109] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 to the size of each encoded data block output from the enabled encoders (step 1444 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 1448 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that many of these algorithms may be lossy, and as such the limits may be subject to or modified by an end target storage, listening, or viewing device. Further notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art. Additionally the content independent data compression threshold may be different from the content dependent threshold and either may be modified by the specific enabled encoders.
[0110] After the compression ratios are compared with the threshold, a determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 1420 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 1420 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 1434 ). A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1436 ).
[0111] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 1420 ), then the encoded data block having the greatest compression ratio is selected (step 1422 ). An appropriate data compression type descriptor is then appended (step 1424 ). A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1426 ).
[0112] After the encoded data block or the unencoded data input data block is output (steps 1426 and 1436 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 1428 ). If the input data stream includes additional data blocks (affirmative result in step 1428 ), the next successive data block is received (step 1432 ), its block size is counted (return to step 1402 ) and the data compression process in repeated. This process is iterated for each data block in the input data stream. Once the final input data block is processed (negative result in step 1428 ), data compression of the input data stream is finished (step 1430 ).
[0113] Since a multitude of data types may be present within a given input data block, it is often difficult and/or impractical to predict the level of compression that will be achieved by a specific encoder. Consequently, by processing the input data blocks with a plurality of encoding techniques and comparing the compression results, content free data compression is advantageously achieved. Further the encoding may be lossy or lossless dependent upon the input data types. Further if the data type is not recognized the default content independent lossless compression is applied. It is not a requirement that this process be deterministic—in fact a certain probability may be applied if occasional data loss is permitted. It is to be appreciated that this approach is scalable through future generations of processors, dedicated hardware, and software. As processing capacity increases and costs reduce, the benefits provided by the present invention will continue to increase. It should again be noted that the present invention may employ any lossless data encoding technique.
[0114] FIGS. 15 a and 15 b are block diagrams illustrating a data compression system employing both content independent and content dependent data compression according to another embodiment of the present invention. The system in FIGS. 15 a and 15 b is similar in operation to the system of FIGS. 13 a and 13 b in that content independent data compression is applied to a data block when the content of the data block cannot be identified or is not associable with a specific data compression algorithm. The system of FIGS. 15 a and 15 b additionally performs content independent data compression on a data block when the compression ratio obtained for the data block using the content dependent data compression does not meet a specified threshold.
[0115] A mode of operation of the data compression system of FIGS. 15 a and 15 b will now be discussed with reference to the flow diagram of FIGS. 16 a - 16 d , which illustrates a method for performing data compression using a combination of content dependent and content independent data compression. A data stream comprising one or more data blocks is input into the data compression system and the first data block in the stream is received (step 1600 ). As stated above, data compression is performed on a per data block basis. As previously stated a data block may represent any quantity of data from a single bit through a multiplicity of files or packets and may vary from block to block. Accordingly, the first input data block in the input data stream is input into the counter module 10 that counts the size of the data block (step 1602 ). The data block is then stored in the buffer 20 (step 1604 ). The data block is then analyzed on a per block or multi-block basis by the content dependent data recognition module 1300 (step 1606 ). If the data stream content is not recognized utilizing the recognition list(s) or algorithms(s) module 1310 (step 1608 ) the data is routed to the content independent encoder module 30 and compressed by each (enabled) encoder E1 . . . En (step 1610 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder E1 . . . En and maintained in a corresponding buffer (step 1612 ), and the encoded data block size is counted (step 1614 ).
[0116] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 to the size of each encoded data block output from the enabled encoders (step 1616 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 1618 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art. Additionally the content independent data compression threshold may be different from the content dependent threshold and either may be modified by the specific enabled encoders.
[0117] After the compression ratios are compared with the threshold, a determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 1620 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 1620 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 1634 ). A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1636 ).
[0118] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 1620 ), then the encoded data block having the greatest compression ratio is selected (step 1622 ). An appropriate data compression type descriptor is then appended (step 1624 ). A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1626 ).
[0119] As previously stated the data block stored in the buffer 20 (step 1604 ) is analyzed on a per block or multi-block basis by the content dependent data recognition module 1300 (step 1606 ). If the data stream content is recognized utilizing the recognition list(s) or algorithms(s) module 1310 (step 1634 ) the appropriate content dependent algorithms are enabled and initialized (step 1636 ) and the data is routed to the content dependent encoder module 1620 and compressed by each (enabled) encoder D1 . . . Dm (step 1638 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder D1 . . . Dm and maintained in a corresponding buffer (step 1640 ), and the encoded data block size is counted (step 1642 ).
[0120] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 to the size of each encoded data block output from the enabled encoders (step 1644 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 1648 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that many of these algorithms may be lossy, and as such the limits may be subject to or modified by an end target storage, listening, or viewing device. Further notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art. Additionally the content independent data compression threshold may be different from the content dependent threshold and either may be modified by the specific enabled encoders.
[0121] After the compression ratios are compared with the threshold, a determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 1648 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 1620 ), then the original unencoded input data block is routed to the content independent encoder module 30 and the process resumes with compression utilizing content independent encoders (step 1610 ).
[0122] After the encoded data block or the unencoded data input data block is output (steps 1626 and 1636 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 1628 ). If the input data stream includes additional data blocks (affirmative result in step 1628 ), the next successive data block is received (step 1632 ), its block size is counted (return to step 1602 ) and the data compression process in repeated. This process is iterated for each data block in the input data stream. Once the final input data block is processed (negative result in step 1628 ), data compression of the input data stream is finished (step 1630 ).
[0123] FIGS. 17 a and 17 b are block diagrams illustrating a data compression system employing both content independent and content dependent data compression according to another embodiment of the present invention. The system in FIGS. 17 a and 17 b is similar in operation to the system of FIGS. 13 a and 13 b in that content independent data compression is applied to a data block when the content of the data block cannot be identified or is not associable with a specific data compression algorithm. The system of FIGS. 17 a and 17 b additionally uses a priori estimation algorithms or look-up tables to estimate the desirability of using content independent data compression encoders and/or content dependent data compression encoders and selecting appropriate algorithms or subsets thereof based on such estimation.
[0124] More specifically, a content dependent data recognition and or estimation module 1700 is utilized to analyze the incoming data stream for recognition of data types, data strictures, data block formats, file substructures, file types, or any other parameters that may be indicative of the appropriate data compression algorithm or algorithms (in serial or in parallel) to be applied. Optionally, a data file recognition list(s) or algorithm(s) 1710 module may be employed to hold associations between recognized data parameters and appropriate algorithms. If the content data compression module recognizes a portion of the data, that portion is routed to the content dependent encoder module 1320 , if not the data is routed to the content independent encoder module 30 . It is to be appreciated that process of recognition (modules 1700 and 1710 ) is not limited to a deterministic recognition, but may further comprise a probabilistic estimation of which encoders to select for compression from the set of encoders of the content dependent module 1320 or the content independent module 30 . For example, a method may be employed to compute statistics of a data block whereby a determination that the locality of repetition of characters in a data stream is determined is high can suggest a text document, which may be beneficially compressed with a lossless dictionary type algorithm. Further the statistics of repeated characters and relative frequencies may suggest a specific type of dictionary algorithm. Long strings will require a wide dictionary file while a wide diversity of strings may suggest a deep dictionary. Statistics may also be utilized in algorithms such as Huffman where various character statistics will dictate the choice of different Huffinan compression tables. This technique is not limited to lossless algorithms but may be widely employed with lossy algorithms. Header information in frames for video files can imply a specific data resolution. The estimator then may select the appropriate lossy compression algorithm and compression parameters (amount of resolution desired). As shown in previous embodiments of the present invention, desirability of various algorithms and now associated resolutions with lossy type algorithms may also be applied in the estimation selection process.
[0125] A mode of operation of the data compression system of FIGS. 17 a and 17 b will now be discussed with reference to the flow diagrams of FIGS. 18 a - 18 d . The method of FIGS. 18 a - 18 d use a priori estimation algorithms or look-up tables to estimate the desirability or probability of using content independent data compression encoders or content dependent data compression encoders, and select appropriate or desirable algorithms or subsets thereof based on such estimates. A data stream comprising one or more data blocks is input into the data compression system and the first data block in the stream is received (step 1800 ). As stated above, data compression is performed on a per data block basis. As previously stated a data block may represent any quantity of data from a single bit through a multiplicity of files or packets and may vary from block to block. Accordingly, the first input data block in the input data stream is input into the counter module 10 that counts the size of the data block (step 1802 ). The data block is then stored in the buffer 20 (step 1804 ). The data block is then analyzed on a per block or multi-block basis by the content dependent/content independent data recognition module 1700 (step 1806 ). If the data stream content is not recognized utilizing the recognition list(s) or algorithms(s) module 1710 (step 1808 ) the data is to the content independent encoder module 30 . An estimate of the best content independent encoders is performed (step 1850 ) and the appropriate encoders are enabled and initialized as applicable. The data is then compressed by each (enabled) encoder E1 . . . En (step 1810 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder E1 . . . En and maintained in a corresponding buffer (step 1812 ), and the encoded data block size is counted (step 1814 ).
[0126] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 to the size of each encoded data block output from the enabled encoders (step 1816 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 1818 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art. Additionally the content independent data compression threshold may be different from the content dependent threshold and either may be modified by the specific enabled encoders.
[0127] After the compression ratios are compared with the threshold, a determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 1820 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 1820 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 1834 ). A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1836 ).
[0128] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 1820 ), then the encoded data block having the greatest compression ratio is selected (step 1822 ). An appropriate data compression type descriptor is then appended (step 1824 ). A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1826 ).
[0129] As previously stated the data block stored in the buffer 20 (step 1804 ) is analyzed on a per block or multi-block basis by the content dependent data recognition module 1300 (step 1806 ). If the data stream content is recognized or estimated utilizing the recognition list(s) or algorithms(s) module 1710 (affirmative result in step 1808 ) the recognized data type/file or block is selected based on a list or algorithm (step 1838 ) and an estimate of the desirability of using the associated content dependent algorithms can be determined (step 1840 ). For instance, even though a recognized data type may be associated with three different encoders, an estimation of the desirability of using each encoder may result in only one or two of the encoders being actually selected for use. The data is routed to the content dependent encoder module 1320 and compressed by each (enabled) encoder D1 . . . Dm (step 1842 ). Upon completion of the encoding of the input data block, an encoded data block is output from each (enabled) encoder D1 . . . Dm and maintained in a corresponding buffer (step 1844 ), and the encoded data block size is counted (step 1846 ).
[0130] Next, a compression ratio is calculated for each encoded data block by taking the ratio of the size of the input data block (as determined by the input counter 10 to the size of each encoded data block output from the enabled encoders (step 1848 ). Each compression ratio is then compared with an a priori-specified compression ratio threshold (step 1850 ). It is to be understood that the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. It is to be further understood that many of these algorithms may be lossy, and as such the limits may be subject to or modified by an end target storage, listening, or viewing device. Further notwithstanding that the current limit for lossless data compression is the entropy limit (the present definition of information content) for the data, the present invention does not preclude the use of future developments in lossless data compression that may increase lossless data compression ratios beyond what is currently known within the art. Additionally the content independent data compression threshold may be different from the content dependent threshold and either may be modified by the specific enabled encoders.
[0131] After the compression ratios are compared with the threshold, a determination is made as to whether the compression ratio of at least one of the encoded data blocks exceeds the threshold limit (step 1820 ). If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit (negative determination in step 1820 ), then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto (step 1834 ). A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1836 ).
[0132] On the other hand, if one or more of the encoded data blocks possess a compression ratio greater than the compression ratio threshold limit (affirmative result in step 1820 ), then the encoded data block having the greatest compression ratio is selected (step 1822 ). An appropriate data compression type descriptor is then appended (step 1824 ). A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal (step 1826 ).
[0133] After the encoded data block or the unencoded data input data block is output (steps 1826 and 1836 ), a determination is made as to whether the input data stream contains additional data blocks to be processed (step 1828 ). If the input data stream includes additional data blocks (affirmative result in step 1428 ), the next successive data block is received (step 1832 ), its block size is counted (return to step 1802 ) and the data compression process in repeated. This process is iterated for each data block in the input data stream. Once the final input data block is processed (negative result in step 1828 ), data compression of the input data stream is finished (step 1830 ).
[0134] It is to be appreciated that in the embodiments described above with reference to FIGS. 13-18 , an a priori specified time limit or any other real-time requirement may be employed to achieve practical and efficient real-time operation.
[0135] Although illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.
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Data compression using a combination of content independent data compression and content dependent data compression. In one aspect, a system for compressing data comprises: a processor; one or more content dependent data compression encoders; and a single data compression encoder. The processor is configured to analyze data within a data block to identify one or more parameters or attributes of the data wherein the analyzing of the data within the data block to identify the one or more parameters or attributes of the data excludes analyzing based solely on a descriptor that is indicative of the one or more parameters or attributes of the data within the data block; to perform content dependent data compression with the one or more content dependent data compression if the one or more parameters or attributes of the data are identified; and to perform data compression with the single data compression encoder, if the one or more parameters or attributes of the data are not identified.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Division of copending application Ser. No. 12/394,108 filed on Feb. 27, 2009, the contents of which are hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The systems and processes disclosed herein relate to the regeneration of spent catalyst in the art of catalytic conversion of hydrocarbons to useful hydrocarbon products, and more particularly to thermocompressors utilized in a continuous catalyst regeneration (CCR) process.
DESCRIPTION OF RELATED ART
[0003] The catalysts used in catalytic processes for the conversion of hydrocarbons tend to become deactivated for one or more reasons. In instances where the accumulation of coke deposits causes the deactivation, regenerating of the catalyst to remove coke deposits can restore the activity of the catalyst. Coke is normally removed from catalyst by contact of the coke-containing catalyst at high temperature with an oxygen-containing gas to combust and remove the coke in a regeneration process. These processes can be carried out in-situ, or the catalyst may be removed from a reactor in which the hydrocarbon conversion takes place and transported to a separate regeneration zone for coke removal. Various arrangements for continuously or semicontinuously removing catalyst particles from a reaction zone and for coke removal in a regeneration zone have been developed.
[0004] Some continuous catalyst regeneration systems provide a thermocompressor to facilitate continued operation of the continuous catalyst regeneration processes during brief periods of operation under low coke conditions. One system utilizing a thermocompressor is described, for example, in PCT Application No. PCT/US2006/062647, the content of which is hereby incorporated by reference in its entirety. A thermocompressor can circulate air from the outlet of the air heater to mix with combustion air going to the cooling zone and provide a net amount of combustion air to the cooling zone. The thermocompressor can utilize combustion air as the motive air, and difficulties in maintaining operation of the system can occur because the net quantity of combustion air in low coke conditions may be insufficient to satisfy the minimum flow requirement for the air heater and/or for cooling the catalyst.
SUMMARY OF THE INVENTION
[0005] The systems and processes disclosed herein relate to continuous catalyst regeneration, particularly to such systems and processes that utilize a plurality of thermocompressors to facilitate continuous catalyst regeneration under low coke conditions.
[0006] In one aspect, a catalyst regeneration system system is provided that includes a catalyst regeneration tower, a first thermocompressor, a second thermocompressor in parallel with the first thermocompressor, and one or more valves. The catalyst regeneration tower includes a cooling zone that receives a catalyst cooling stream. The first thermocompressor utilizes a first motive vapor. The second thermocompressor utilizes nitrogen as a motive vapor. The one or more valves can selectively direct a cooled stream to at least one of the first thermocompressor or the second thermocompressor to produce the catalyst cooling stream.
[0007] In a second aspect, a process for providing a catalyst cooling stream to a catalyst regeneration tower is provided that includes selectively providing a cooled stream to at least one of a first thermocompressor or a second thermocompressor, to produce a catalyst cooling stream. and The first thermocompressor utilizes a first motive vapor. The second thermocompressor utilizes a second motive vapor. The catalyst cooling stream can be provided to a catalyst cooling zone in a catalyst regeneration tower.
[0008] In a third aspect, a process for regenerating catalyst is provided that includes removing a first gas stream from a regeneration tower, passing the first gas stream to an air heater to form a heated first gas stream, dividing the heated first gas stream to form a regeneration tower return stream and a cooling loop stream, cooling the cooling loop stream in a cooling zone cooler to form a cooled stream, selectively providing the cooled stream to at least one of a first thermocompressor or a second thermocompressor to produce a catalyst cooling stream, and providing the catalyst cooling stream to the regeneration tower. The first thermocompressor utilizes a first motive vapor. The second thermocompressor utilizes a second motive vapor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Specific examples have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, forming a part of the specification.
[0010] FIG. 1 is a simplified flow diagram of a portion of a continuous catalyst regeneration process that includes a cooling gas loop.
DETAILED DESCRIPTION
[0011] FIG. 1 is a simplified flow diagram of a continuous catalyst regeneration (CCR) system indicated generally at 100 . As illustrated, spent catalyst 102 can be removed from a reactor and provided to a catalyst regeneration tower 104 . The catalyst regeneration tower 104 can have a plurality of regeneration zones or stages through which the spent catalyst passes when undergoing regeneration. As illustrated, regeneration tower 104 includes a combustion zone 106 , a halogenation zone 108 , a drying zone 110 , and a cooling zone 112 . Spent catalyst can enter the regeneration tower 104 through an inlet at the top of the regeneration tower 104 . Upon entering the regeneration tower 104 , the spent catalyst can undergo the regeneration process by entering combustion zone 106 , and then subsequently proceeding through the halogenation zone 108 , the drying zone 110 , and the cooling zone 112 . Regenerated catalyst 114 can be removed from the catalyst regeneration tower 104 , and can be returned to the reactor.
[0012] As illustrated in FIG. 1 , the continuous catalyst regeneration process 100 has a cooling gas loop 116 . Cooling gas loop 116 includes a first gas stream 118 that is removed from a cooling zone outlet 120 in the cooling zone 112 of the regeneration tower 104 . First gas stream 118 can contain air, and can have a temperature of from about 300° F. (149° C.) to about 1000° F. (538° C.). First gas stream 118 can be passed through a conduit to an air heater 122 . Air heater 122 heats the first gas stream 118 , for example to a temperature of about 1050° F. (566° C.), to form a heated first gas stream 124 . The heated first gas stream 124 exits the air heater 122 , and can be divided into at least two gas streams, including a regeneration tower return stream 126 and a cooling loop stream 128 . The regeneration tower return stream 126 can be passed through a conduit back to the regeneration tower 104 , and can be provided to the drying zone 110 . After it enters the drying zone, the gas in the regeneration tower return stream 126 can rise within the regeneration tower 104 , and can be utilized in the combustion zone 106 .
[0013] The cooling loop stream 128 can be passed through a conduit to a cooling zone cooler 130 . Cooling zone cooler 130 can be a heat exchanger, and is preferably an indirect heat exchanger such as, for example, a double pipe heat exchanger, or a shell and tube type heat exchanger. When the cooling zone cooler 130 is a shell and tube exchanger, the cooling loop stream 128 can be passed through the tube side of the cooling zone cooler 130 to form cooled stream 132 .
[0014] The cooling zone cooler 130 can be cooled with any suitable medium, such as air or water. For example, as illustrated in FIG. 1 , a cooler blower 134 can receive atmospheric air, or ambient air from the outdoors, and can provide an atmospheric air stream 136 to the cooling zone cooler 130 to act as a cooling fluid for cooling loop stream 128 . When cooling zone cooler is a shell and tube type heat exchanger, for example, atmospheric air stream 136 can be provided to the shell side of the cooling zone cooler 130 .
[0015] As shown in FIG. 1 , cooling gas loop 116 can include one or more thermocompressors, such as a first thermocompressor 138 and a second thermocompressor 140 . Generally, the thermocompressors 138 and 140 can utilize the kinetic energy of a primary fluid, such as the first and second motive vapors described below, to pump a secondary fluid, such as cooled stream 132 . The first thermocompressor can utilize a first motive vapor, and the second thermocompressor can utilize a second motive vapor. The second motive vapor can preferably have a composition that is different from the composition of the first motive vapor. For example, as illustrated in FIG. 1 , first thermocompressor 138 can utilize combustion air as the first motive vapor, and second thermocompressor 140 can utilize nitrogen as the second motive vapor.
[0016] First thermocompressor 138 and second thermocompressor 140 are preferably configured to operate in parallel. The cooled stream 132 can be selectively directed, and can be provided to at least one of the first thermocompressor or the second thermocompressor to produce a catalyst cooling stream 148 . The cooled stream 132 can form at least part of the catalyst cooling stream 148 . Catalyst cooling stream 148 can also include the motive vapor of any thermocompressor to which the cooled stream 132 is provided. Catalyst cooling stream 148 can thus include the first motive vapor, the second motive vapor, or both the first and second motive vapors. Catalyst cooling stream 148 can be passed through a conduit to an inlet 150 of the regeneration tower 104 , and can be provided to the cooling zone 112 of the catalyst regeneration tower 104 .
[0017] The cooled stream 132 can be provided to the first thermocompressor 138 , to the second thermocompressor 140 , or can be divided and provided to both the first thermocompressor 138 and the second thermocompressor 140 . One or more valves, such as illustrated valve 154 , can be utilized to selectively direct the cooled stream 132 . The one or more valves can be operated by one or more switches, such as, for example, a software switch. The cooled stream 132 can be selectively directed based upon operating conditions, including, but not limited to, catalyst coke level, instrument header pressure, and other operating conditions.
[0018] In some instances, it may be desirable to operate the first thermocompressor 138 during a first set of operating conditions, and to operate the second thermocompressor 140 during a second set of operating conditions. For example, the cooling gas loop 116 can utilize first thermocompressor 138 under normal operating conditions, or for short term operations under low coke conditions, and can utilize second thermocompressor 140 for operation during periods of continuous low coke conditions.
[0019] With respect to the utilization of the first thermocompressor 138 , the first motive vapor 142 can be supplied to the first thermocompressor 138 through dryer 144 . As shown in FIG. 1 , dryer 144 can receive a gas stream 146 , and can supply motive vapor 142 through a conduit to the first thermocompressor 138 . The gas stream 146 can be air, and can include oxygen and nitrogen. The flow rate or amount of the first motive vapor 142 can be controlled based upon the amount of oxygen required by the combustion zone 106 . The flow rate for the first motive vapor 142 can be based on a reduced combustion air rate, such as, for example, about 25% of the design combustion air, and a reduced instrument air header pressure, such as, for example, a pressure that is about 10 psi lower than the pressure available under normal operating conditions.
[0020] To facilitate the operation of the first thermocompressor 138 under certain conditions, such as, for example, longer term low coke or very low coke operation conditions, a nitrogen stream 152 can be provided and combined with the first motive vapor 142 to add motive flow for the first thermocompressor 138 . The nitrogen stream 152 can provide added motive gas flow and gas pressure to help satisfy the process requirements, the nitrogen results in reduced oxygen concentration in the chlorination zone of the regeneration tower. Over extended periods of time, however, the lower oxygen concentration in the chlorination zone of the regeneration tower may adversely impact the quality of the catalyst regeneration.
[0021] With respect to utilization of the second thermocompressor 140 , nitrogen stream 152 can be received by the second thermocompressor 140 , and can act as the second motive vapor for the second thermocompressor 140 . Nitrogen stream 152 can consist substantially completely of nitrogen. The nitrogen stream 152 can be provided to the second thermocompressor 140 at a higher pressure than the combustion air utilized as the motive vapor for first thermocompressor 138 . The second thermocompressor 140 can thus operate at a higher ratio of load gas to motive gas than the first thermocompressor 138 . The higher ratio can provide additional load gas flow to maintain long term low coke operation while maintaining an appropriate oxygen concentration in the halogenation zone 108 of the regeneration tower 104 . In some examples, the pressure of nitrogen stream 152 can be from about 30 psi to about 300 psi higher than the pressure of the combustion air utilized as the motive vapor for the first thermocompressor 138 . The flow rate of nitrogen stream 152 can preferably be controlled to maintain the oxygen content in the halogenation zone 108 at a level of above about 10%, and preferably at a level of above about 18%.
[0022] From the foregoing, it will be appreciated that although specific examples have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit or scope of this disclosure. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to particularly point out and distinctly claim the claimed subject matter.
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Systems and processes for regenerating catalyst are provided herein that include a catalyst regeneration tower having a cooling zone that receives a catalyst cooling stream generated by a cooling gas loop. The systems and processes include a first thermocompressor that utilizes a first motive vapor and a second thermocompressor that utilizes a second motive vapor in order to provide the catalyst cooling stream to the regeneration tower. The second thermocompressor operates in parallel with the first thermocompressor. The first thermocompressor can utilize combustion air as the motive vapor. The second thermocompressor can utilize nitrogen as the motive vapor.
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BACKGROUND
This invention relates generally to memory devices and particularly to memory devices with a multi-level cell architecture.
A multi-level cell memory is comprised of multi-level cells, each of which is able to store multiple charge states or levels. Each of the charge states is associated with a memory element bit pattern.
A flash EEPROM memory cell, as well as other types of memory cells, is configurable to store multiple threshold levels (V t ). In a memory cell capable of storing two bits per cell, for example, four threshold levels (V t ) are used. Consequently, two bits are designated for each threshold level. In one embodiment, the multi-level cell may store four charge states. Level three maintains a higher charge than level two. Level two maintains a higher charge than level one and level one maintains a higher charge than level zero. A reference voltage may separate the various charge states. For example, a first voltage reference may separate level three from level two, a second voltage reference may separate level two from level one and a third reference voltage may separate level one from level zero.
A multi-level cell memory is able to store more than one bit of data based on the number of charge states. For example, multi-level cell memory that can store four charge states can store two bits of data, a multi-level cell memory that can store eight charge states can store three bits of data, and a multi-level cell memory that can store sixteen charge states can store four bits of data. For each of the N-bit multi-level cell memories, various memory element bit patterns can be associated with each of the different charge states.
The number of charge states storable in a multi-level cell, however, is not limited to powers of two. For example, a multi-level cell memory with three charge states stores 1.5 bits of data. When this multi-level cell is combined with additional decoding logic and coupled to a second similar multi-level cell, three bits of data are provided as the output of the two-cell combination. Various other multi-level cell combinations are possible as well.
The higher the number of bits per cell, the greater the possibility of read errors. Thus, a four bit multi-level cell is more likely to experience read errors than a one bit cell. The potential for read errors is inherent in the small differential voltages used to store adjacent states. If the stored data is potentially lossy, sensitive data stored in relatively high-density multi-level cells may be subject to increased error rates.
In many applications, the nonvolatile memories store a large amount of data that is tolerant to a small number of bit errors. Applications may also have a small amount of data that is not tolerant to bit errors. Examples of such applications may include control structures, header information, to mention a few examples. These typical applications, where a relatively small amount of the overall storage requires higher fidelity, may include digital audio players, digital cameras, digital video recorders, to mention a few examples.
Thus, there is a need for a way to store a large amount of data in dense multi-level cells while ensuring that sensitive data is stored in a fashion that sufficiently reduces the possibility of read errors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block depiction of one embodiment of the present invention;
FIG. 2 is a depiction of a cell in accordance with one embodiment of the present invention;
FIG. 3 is a depiction of another cell in accordance with another embodiment of the present invention;
FIG. 4 is a depiction of still another cell in accordance with one embodiment of the present invention; and
FIG. 5 is a flow chart for software in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1, a processor 100 may be coupled through a bus 102 to a multi-level cell memory 104 . The memory 104 contains an interface controller 105 , a write state machine 106 and a multi-level cell memory array 150 . The processor 100 is coupled by the bus 102 to both the interface controller 105 and the memory array 150 in one embodiment of the present invention. The interface controller 105 provides control over the multi-level cell memory array 150 . The write state machine 106 communicates with the interface controller 105 and the memory array 150 . The interface controller 105 passes data to be written into the array 150 to the state machine 106 . The state machine 106 executes a sequence of events to write data into the array 150 . In one embodiment, the interface controller 105 , the write state machine 106 and the multi-level cell memory array 150 are located on a single integrated circuit die.
Although embodiments are described in conjunction with a memory array 150 storing one, two or four bits per cell, any number of bits may be stored in a single cell, for example, by increasing the number of threshold levels, without deviating from the spirit and scope of the present invention. Although embodiments of the present invention are described in conjunction with a memory array 150 of flash cells, other cells such as read only memory (ROM), erasable programmable read only memory (EPROM) conventional electrically erasable programmable read only memory (EEPROM), or dynamic random access memory (DRAM), to mention a few examples, may be substituted without deviating from the spirit and scope of the present invention.
Referring to FIG. 2, a cell may include only one bit of data at the first and last states of the cell. In the embodiments shown in FIGS. 2, 3 and 4 , the actual storage of data is indicated by an X and empty states are indicated by dashes. A similarly sized cell, shown in FIG. 3, may store two bits per cell at every fifth level within the cell. Likewise, as shown in FIG. 4, the same sized cell may store four bits per cell using every single state or level of the sixteen available states in this example.
Thus, in some embodiments of the present invention, the number of bits per cell may be changed to increase the fidelity of the stored data. Thus, if density is more important than fidelity, the scheme shown in FIG. 4 or other higher density schemes may be utilized. Conversely, when fidelity is more important, the data may be spread in the cell, decreasing the density per cell and increasing the number of cells required to store all of the data. With wider spacing between the states that are utilized, the integrity of the data storage will be improved. This is because it is easier to discern the differential voltage between significantly nonadjacent levels. In fact, the greater the distance between the levels, the easier it is to discern a differential voltage.
Thus, in the embodiment shown in FIG. 2, only two levels are used, and in the embodiment shown in FIG. 3, four levels are used. In the embodiment shown in FIG. 4, all sixteen levels are utilized in accordance with some embodiments of the present invention.
Thus, in some embodiments, data may be stored in varying numbers of bits per cell depending on the type of data involved. Thus, some data may be packed closely as indicated for example in FIG. 4 and other data may be spread farther apart, requiring additional numbers of cells to complete the data storage.
Thus, turning to FIG. 5, the write algorithm 122 , which may be implemented in software or hardware, initially identifies the number of bits per cell. The number of bits per cell may be derived from information included with the data indicating the desired fidelity. Based on the number of bits per cell, the packing of bits into each given cell may be adjusted. Thus, in some cases, denser packing may be utilized, for example as shown in FIG. 4, and in other cases, looser or more spread apart packing may be utilized as shown in FIG. 2 . Once the number of bits per cell has been determined as indicated in block 124 , the packing of bits into each cell is adjusted as indicated in block 126 . Finally the bits are written to the cells as indicated in block 128 . The number of bits per cell may be changed on the fly from cell to cell.
The read process simply reverses the flow, ignoring the missing levels, and simply reading the actual data out of each cell. The spread apart data may then be repacked into a continuous data string.
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
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There exists a tradeoff between the fidelity of data storage and the number of bits stored in a memory cell. The number of bits may be increased per cell when fidelity is less important. The number of bits per cell may be decreased when fidelity is more important. A memory, in some embodiments, may change between storage modes on a cell by cell basis.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The subject matter of this application is related to the subject matter of our copending application, Ser. No. 07/190,704, filed May 5, 1988, entitled "Apparatus For Transferring Bulk Material by Outgoing and Returning Paths of an Endless Belt," and assigned to Bridgestone Corporation, the assignee of the present application; is related to the subject matter of our copending application, Ser. No. 07/062,246, filed June 15, 1987, entitled "A Tubular Belt Conveyor," and assigned to Japan Pipe Conveyor Co., Ltd.; is related to the subject matter of our application, Ser. No. 07/028,197, filed Mar. 20, 1987, entitled "Method of Conveying Materials and Tubular Belt Conveyor Therefor," and assigned to Bridgestone Corporation, the assignee of the present application, issued as U.S. Pat. No. 4,747,344 on May 31, 1988; and is related to the subject matter of an application of Kunia Hashimoto, Ser. No. 06/884,471, filed July 11, 1986, entitled "Belt Conveyor," now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a tubular belt conveyor and more particularly to a tubular belt conveyor which comprises a belt guiding device for preventing a belt from loosening or expanding so as to assure smooth running.
As shown in FIG. 10, there is a conventional tubular belt conveyor in which an endless band-shaped conveyor belt 1 is rolled up into a tubular shape, flattened portions at the front and rear ends are wound around a front and a rear end roller to convey material which is thrown onto the front end of a forward belt 1a from a hopper 4 and is discharged onto a receiver 5 at the rear end.
The portion between a flat and a tubular portion or between a tubular and a flat portion is called "a through converting portion", and the distance therebetween is called "a trough converting distance".
In the conventional tubular belt conveyor, nylon or steel is employed as core material for the endless conveyor belt 1. As shown by a solid line in FIG. 11, the core material made of nylon is liable to lengthen and the trough converting distance is small, while what is made of steel is difficult to lengthen and the trough converting distance is large, as shown in a dotted line.
FIG. 11 shows a triangle representing the relationship between the elongation and the trough converting distance for an endless conveyor belt made of different material. The center line and both the side ends of the conveyor belt 1 are corresponding to the base and the hypotenuse of the triangle respectively. That is to say, the hypotenuse is longer than the base, which means that the side ends of the belt 1 are stretched longer than the center line.
Generally, the trough converting distance of the endless conveyor belt 1 is determined to keep the elongation less than 1%. The elongation less than 1% is within elasticity, and when the belt is formed into a tubular shape, the tubular belt becomes to have the same elongation over the whole width. In the endless steel-core conveyor belt 1, the trough converting distance lengthens so that the difference between the hypotenuse and the base becomes smaller.
As shown in FIG. 12, if the trough converting distance lengthens, the trough converting portion at the beginning part of the return belt 1b loosens by its weight, and the loosened portion increases because of the frictional resistance to which it is subject when it runs through a belt shape maintaining frame 6. Therefore, when the endless conveyor belt 1 is driven, said loosened trough converting portion moves up and down to cause surging action, so that the conveyor belt 1 travels intermittently. In other words, the running speed of the conveyor belt is not constant and the intermittent shock occurs in the belt, so that it is subject to large tension. Therefore, the front and rear end rollers around which the conveyor belt 1 is wound undergo strong force.
Also, if the conveyed material supplied from the hopper 4 is loaded ununiformly on the forward belt 1 at the trough converting portion of the beginning part, the forward belt 1a totally twists, or the side end of the belt expands over the usual tubular form because of the weight of the conveyed material, so that the elongation of the side ends of the belt increases, and the load of the belt and the weight of the conveyed material make the belt loosened, which results in the problems as mentioned above.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a tubular belt conveyor comprising a belt guiding device to prevent a belt from loosening or expanding at a trough converting portion so as to assure smooth running.
According to the present invention, there is provided a tubular belt conveyor comprising a front end roller provided at the front end of the conveyor a rear end roller provided at the rear end an endless belt which is rolled up into a tubular shape for conveying material, flat portions of the belt being wound around the front and rear end rollers so that the belt may circulate between the two end rollers and a belt guiding device disposed at the portion in which the belt is rolled up from a flat shape into a tubular shape, the device comprising a base plate and a plurality of guide frames provided on said base plate the guide frame having a plurality of guide rollers arranged like a circle through which the belt to be rolled up passes, the improvement comprising that the diameter of the circle formed by the guide rollers within the guide frame increases gradually towards the front or the rear end roller.
Therefore, even if the belt is twisted around its longitudinal axis or expanded to open by the weight of the conveyed material or itself, it can be guided smoothly in a circular or an arcuate form such that its diameter increases or decreases gradually. When twisted, the belt only moves within the inscribed circle of each guide frame, but no adverse effect can be created during running.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects as well as advantages of the present invention will become clear by the following description of a preferred embodiment of the present invention with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic side view of a tubular belt conveyor according to the present invention in which a belt guide device is provided at the beginning part of a return belt;
FIG. 2 is a vertical sectional view taken along line A--A in FIG. 1;
FIG. 3 is an enlarged plan view of the terminating end of the forward belt in the tubular belt conveyor shown in FIG. 1;
FIG. 4 is a side elevational view taken in the direction of the arrows B--B in FIG. 3;
FIG. 5 is an enlarged sectional view taken along line C--C in FIG. 4;
FIG. 6 is an enlarged sectional view taken along line D--D in FIG. 4;
FIG. 7 is an enlarged sectional view taken along line E--E in FIG. 4;
FIG. 8 is a sectional view showing another embodiment of a conveyor belt to which the present invention applies;
FIG. 9 is a sectional view showing a conveyor belt supported by rollers connected by links;
FIG. 10 is a schematic side view of a conventional tubular belt conveyor and similar to FIG. 1;
FIG. 11 is a view showing the relationship between elongation and trough converting distance for different core material, when an endless conveyor belt is employed for a tubular belt conveyor; and
FIG. 12 is a side view similar to FIG. 4 and illustrates the conventional tubular belt conveyor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The embodiments according to the present invention will be described in detail with reference to FIGS. 1 to 9 in appended drawings. To the parts common with those in the prior arts illustrated in FIGS. 10 to 12, tne same numerals will be given.
FIG. 1 schematically shows a tubular belt conveyor according to the present invention in which a belt guiding device is provided at the beginning part of a return path of an endless conveyor belt. An endless conveyor belt 1, the flattened front and rear end of which are wound around a front end roller 2 and a rear end roller 3 respectively, is circulated in a direction shown by an arrow by means of drive means (not shown).
A plurality of belt shape maintaining frames 6 are provided between two end rollers 2 and 3. Between a front end belt shape maintaining frame 6 and a flattened part at the beginning end, namely, a trough converting portion, a belt guiding device 7 is disposed. The numerals 1a and 1b represent a forward and a return path respectively.
As shown in FIG. 2, each belt shape maintaining frame 6 is divided into an upper compartment 6b and a lower compartment 6c each of which includes in the center an opening 6a through which the conveyor belt 1 passes. Within each compartment 6b and 6c, a plurality of belt shape maintaining rollers 8 are arranged like a circle around the opening 6a. The numeral 9 represents conveyed material.
As shown in FIGS. 3 and 4, the return path 1b running around the front end roller 2 is supported by the belt guiding device 7 at the trough converting portion adjacent to the first belt shape maintaining frame 6. The belt guiding device 7 comprises a base plate 70 which is located below the return path along its moving direction to support a first, a second and a third hexagonal guide frame 71, 72 and 73.
As shown in FIG. 5, the first hexagonal guide frame 71 includes in the center a circular opening 71a through which the conveyor belt 1 passes, and six guide rollers 10 are arranged like a circle inside the opening 71a. These guide rollers 10 engage with the circumference of the belt 1 to guide it.
As shown in FIGS. 6 and 7, the second and third hexagonal guide frames 72 and 73 are similar to the first hexagonal guide frame 71 in structure, as mentioned above. The three frames are analogous and become smaller in order. Especially, it should be noted that the diameters 71b, 72b and 73b of inscribed circles formed by connecting the outer peripheries of the guide rollers 10 becomes smaller gradually.
This belt guiding device 7 may be used in combination with lobe-shaped rollers (not shown) which support the return belt of the trough converting portion 1c.
In FIG. 1, the numeral 11 shows a flow-down tube which is integrally connected with the hopper 4.
The function which is performed by the invention in the above-mentioned embodiment will be desecribed hereafter. Fluidizable powdered material 9 in the hopper 4 flows down through the flow-down tube 11 onto the forward path 1a, which runs through each belt shape maintaining frame 6. The forward path 1a which gets out of the belt shape maintaining frame provided near front end roller 2 opens, so that the conveyed material 9 is thrown onto a receiver 5 surrounding the front end roller 2.
The return path 1b travelling around the front end roller 2 is subject to frictional resistance when it enters into the belt shape maintaining frame 6 provided at the front end. Thus, the trough converting portion becomes slackened. But, the slackness can be decreased by the guide frames 71, 72 and 73 so as to guide the return path 1b into the belt shape maintaining frame 6 smoothly, and, then, this return path 1b passes through the lower compartment 6c in each belt shape maintaining frame 6 to come back to the rear end roller 3 for circulation.
The embodiment mentioned above relates to a tubular belt conveyor in which a flattened belt is rolled up into a tubular shape by overlapping the inner surface of one side end on the outer surface of the other side end along its entire length, but the present invention may also apply to a tubular belt conveyor in which a flattened belt is rolled up by contacting the inner surfaces of both side ends with each other to form a projection as shown in FIG. 8, or by contacting or approaching the side edges to each other along its entire length.
Also, as shown in FIG. 9, the present invention may apply to a tubular belt conveyor in which a conveyor belt 81 is supported by a conventional embodiment with three upper rollers 82 and three lower rollers 82 connected by an upper and a lower link 83 and 84 respectively which may be used like a guide frame with the present invention. The links 83 and 84 are supported at the side ends by a U-shaped support frame 85. The conventional rollers 82, links 83 and 84 and frame 85 may be used to form guide frames with rollers 82 forming circles of gradually decreasing diameters that may be used for the belt guiding device in the present invention to prevent a belt from loosening so as to assure smooth running. In such a conveyor, the forward and return paths are arranged side by side horizontally, which is different from a vertical arrangement in the foregoing embodiments.
Further, the embodiment mentioned above describes a belt guiding device provided on the trough converting portion at the beginning part of the return belt to prevent the belt from loosening. However, the device may be provided at the beginning part of the forward belt. In this case, it not only prevents the belt from loosening which is caused by the weight of the conveyed material, but also the belt can be smoothly guided as a tubular or arcuated shape even if the belt is twisted or is loaded to open the side edge of the belt.
Also, the belt guiding device may be provided at the terminating end of the forward or the return path, whereby the belt may be guided smoothly as well.
In each guide frame 71, 72 and 73 of the above-mentioned embodiments, the guide rollers 10 are arranged like a hexagon, but may be like other polygons.
The belt guiding device according to the present invention may be located at any trough converting portion of the beginning and the terminating parts of the forward or the return path of the belt. By the location, the belt can be smoothly guided in a tubular or an arcuate form without disadvantages such as loosening or spreading of the opening, even if the belt is twisted around its lonitudinal axis or is undesirably loaded by the weight of conveyed material or belt itself. Therefore, it is advantageous to prevent the belt from surging at the trough converting portion so that it may always run at constant speed and not to give the belt large stress which effects impact to members such as the front or the rear end roller.
It should be noted that the foregoing only relates a preferred embodiment of the present invention, and that modification or variation may be made by person skilled in the art without departing from the spirit of the invention.
The scope of the invention is therefore to be determined solely by the appended claims:
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A tubular belt conveyor can transport powdered or granular material without leakage. To roll up a flat belt into a tubular shape, a belt guiding device is provided in the vicinity of a front or a rear end roller. The belt guiding device comprises a base plate and a plurality of guide frames provided on the base plate. In the guide frame, a plurality of guide rollers are arranged like a circle through which the belt to be rolled up passes. The diameter of the circle formed by the guide rollers increases gradually towards the front or the rear end roller to prevent the belt from slacking so that smooth running may be assured.
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This invention relates to golf, in particular to devices, apparatus, and methods of storing and releasing a ball marker on a putter head.
BACKGROUND AND PRIOR ART
Golf is an extremely popular game where the players are constantly playing up to 18 holes per game usually with other players. A common problem occurs when more than one player is ready to make the final shot. Typically, these short shots require the use of a putter. When multiple parties are playing, it is normal for the players to pick up their balls until they are ready to take their turn. However, picking up the ball can create a problem if the player is not able to place the ball back in the exact spot from which it needs to be played. Markers such as a metal disc or coins are sometimes used to mark the player's spot until the player is ready. However, many players do not try to carry loose items on their person to use with marking the spot on the ground for the ball.
Various types of markers with golf clubs have been proposed over the years. See for example, U.S. Pat. Nos. 3,595,582 to Chapman; 3,749,408 to Mills; 4,017,082 to Channing et al.; 5,417,426 to Bayer; 5,605,510 to Schmidt et al.; 5,972,144 to Hsu; 6,200,226 to Regan; 6,425,831 to Heene et al.; 6,692,376 to Kosovac et al.; 6,729,972 to Boord; 7,059,971 to Schmitt; 7,172,517 to Phelps et al.; 7,510,484 to Tavares et al.; 7,749,105 to Zielke et al. and U.S. Patent Application Publications: 2002/0147055 to French; 2003/0153400 to Boord; 2004/0038746 to Wahl et al.; 2005/0221908 to Gornall; 2007/0191131 to Nickel; 2009/0029800 to Jones et al.; 2010/0087269 to Snyder et al.; 2010/0113182 to Franklin et al.
While some of the references show markers, the references primarily generally the markers be placed on the upper surface of the putter close to one of the sides of the putter. This non-central placement location would mean that the extra weight of the marker can potentially effect the use the putter by changing the balance of the putter head during play. Also, the upper locations may allow for accidental releases of the marker before, after or during play. Additionally, cut-outs in the top of the putter can detract from the appearance of the smooth lines and surfaces on the putter, and create an unaesthetic effect. Some of the references require openings on both the top and bottom of the putter to access the markers. Additionally, the references generally require the use of magnets which means that non-metal markers would not be able to stored. Thus, many of these attempted solutions create other problems to the player. Thus, the need exists for solutions to the above problems with the prior art.
SUMMARY OF THE INVENTION
A primary objective of the present invention is to provide devices, apparatus, and methods of storing and releasing a ball marker on a putter head having a marker storage compartment close to the center of mass of the putter head thereby not offsetting the balance of the putter head during play.
A secondary objective of the present invention is to provide devices, apparatus, and methods of storing and releasing a ball marker on a putter head, wherein the marker can easily be slid along the bottom of the putter into a storage location, and easily retrieved by sliding the marker out of the storage location underneath the putter.
A third objective of the present invention is to provide devices, apparatus, and methods of storing and releasing a ball marker on a putter head having a storage compartment that is not visibly located on or is accessible through the top of the putter.
A fourth objective of the present invention is to provide devices, apparatus, and methods of storing and releasing a ball marker on a putter head, wherein a metal marker can be held in place by a permanent magnet.
A fifth objective of the present invention is to provide devices, apparatus, and methods of storing and releasing a ball marker on a putter head, wherein metal and nonmetal markers can be held in place through track shaped side walls with friction.
A sixth objective of the present invention is to provide devices, apparatus, and methods of storing and releasing a ball marker on a putter head, wherein markers can be held in place through track shaped side walls with friction with permanent magnets.
A preferred embodiment of the golf club with compartment for holding a ball marker can include a head of a golf club having a bottom side, a top side, and front side, rear side, left side and right side, a longitudinal compartment in the bottom side of the golf club head, the compartment having a opening through the rear side of the head adjacent to the bottom, and the compartment having closed side walls, a closed upper wall, and an opening in a lower wall of the compartment through the bottom side of the golf club head, and a ball marker that is slid into and out of the opening in the rear side of the gulf club head into the compartment, so that the ball marker is held within the compartment. The golf club can be a putter.
The longitudinal compartment can be oblong shaped and is located under a center of gravity of the golf club head. A magnet can be located adjacent to the closed upper wall of the compartment for holding the marker in the compartment.
An alternative compartment can include track slots, such as a T-shaped slot along the side walls of the compartment for allowing edges of the marker to slide therein by friction between the edges of the marker and the track slots in side walls of the compartment.
Also, a magnet can be located adjacent to the closed upper wall of the compartment for holding the marker in the compartment, along with the track slots along the side walls of the compartment for allowing edges of the marker to slide therein.
The golf club can include an opening in the top side of the head for placing removable plate with indicia. A removable circular disc as the plate can have an upper surface for the indicia. Alternatively, a removable rectangular plate having an upper surface for the indicia.
The upper removable plate can be metal and can be held in place by another magnet for attaching the removable indicia plate to the opening in the top side of the head.
The golf club can also have a surface on the front side of the golf club head for placing a removable indicia plate thereon. Another magnet can be used for attaching the removable metal indicial plate thereon.
In a preferred embodiment, the ball marker can be metal and is held in place by the permanent magnet on the bottom side of the head. Also, a nonmetal marker, such as a plastic marker can be held in place by the T-slot shaped cavity.
Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a top front perspective view of the novel putter head.
FIG. 2 is a top rear perspective view of the putter head of FIG. 1 .
FIG. 3 is a bottom front perspective view of the putter head of FIG. 1 .
FIG. 4 is a bottom rear perspective view of the putter head of FIG. 1 .
FIG. 5 is a bottom rear perspective view of the putter head of FIG. 1 with ball marker removed.
FIG. 6 is a front side view of the putter head of FIG. 1 .
FIG. 7 is a rear side view of the putter head of FIG. 1 .
FIG. 8 is a right side view of the putter head of FIG. 1 .
FIG. 9 is a left side view of the putter head of FIG. 1 .
FIG. 10 is a top side view of the putter head of FIG. 1 .
FIG. 11 is a bottom side view of the putter head of FIG. 1 with ball marker in place.
FIG. 12 is another bottom view of the putter head of FIG. 11 with ball marker removed.
FIG. 13 is a top front exploded perspective view of the putter head of FIG. 1 .
FIG. 14 is a bottom rear exploded perspective view of the putter head of FIG. 1 .
FIG. 15 is a top front perspective view of another embodiment of the novel putter head
FIG. 16 is a top rear perspective view of the putter head of FIG. 15 .
FIG. 17 is a bottom front perspective view of the putter head of FIG. 1 .
FIG. 18 is a bottom rear perspective view of the putter head of FIG. 1 .
FIG. 19 is a bottom front perspective view of putter head with ball marker removed.
FIG. 20 is a front view of the putter head of FIG. 15 .
FIG. 21A is a rear view of the putter head with detail of T-Slot ball marker holder.
FIG. 21B is an enlarged view of the T-slot ball marker holder compartment of FIG. 21A .
FIG. 22 is a left side view of the putter head of FIG. 15 .
FIG. 23 is a right side view of the putter head of FIG. 15
FIG. 24 is a top view of the putter head of FIG. 15 .
FIG. 25 is a bottom view of the putter head of FIG. 15 with ball marker in T-Slot holder.
FIG. 26 is a bottom view of the putter head of FIG. 25 with ball marker removed from T-Slot holder.
FIG. 27 is a top front exploded view of the putter head of FIG. 15 .
FIG. 28 is a bottom front exploded view of the putter head of FIG. 15 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
A components will now be described.
10 . Putter head with cavity and magnet for ball marker. Square logo plate shown. 20 . Putter head with slot and magnet for ball marker. Round logo plate shown. 30 . Square logo plate. 40 . Round logo plate. 50 . Ball marker. 60 . Lead weight. 65 . Optional magnet on front face of weight 70 . Magnet to retain ball marker. 80 . Advertising plate covers lead weight. 90 . Putter shaft (prior art). 100 . Sight line. 110 . T-slot for ball marker. 120 . Body of putter head. 122 . Bottom of putter head. 126 . Rear(back) of putter head. 128 . Front face of putter head 130 . Cavity for ball marker. 132 . side opening to cavity through lower rear wall of putter head 120 138 . closed sidewalls of cavity 140 . Cavity for lead weight. 150 . Cavity for square logo plate. 155 . Optional magnet in cavity 150 160 . Cavity for round logo plate. 170 . Cavity for magnet. 180 . Hole for shaft.
Slidable Magneticaly Held Marker
FIG. 1 is a top front perspective view of the novel putter head 10 . FIG. 2 is a top rear perspective view of the putter head 10 of FIG. 1 . FIG. 3 is a bottom front perspective view of the putter head 10 of FIG. 1 . FIG. 4 is a bottom rear perspective view of the putter head 10 of FIG. 1 . FIG. 5 is a bottom rear perspective view of the putter head 10 of FIG. 1 with ball marker 50 removed. FIG. 6 is a front side view of the putter head 10 of FIG. 1 . FIG. 7 is a rear side view of the putter head 10 of FIG. 1 . FIG. 8 is a right side view of the putter head 10 of FIG. 1 . FIG. 9 is a left side view of the putter head 10 of FIG. 1 . FIG. 10 is a top side view of the putter head 10 of FIG. 1 . FIG. 11 is a bottom side view of the putter head 10 of FIG. 1 with ball marker in place. FIG. 12 is another bottom view of the putter head 10 of FIG. 11 with ball marker 50 removed. FIG. 13 is a top front exploded perspective view of the putter head 10 of FIG. 1 . FIG. 14 is a bottom rear exploded perspective view of the putter head 10 of FIG. 1 .
Referring to FIGS. 1-14 , the novel putter 10 includes a putter head 20 that can have a putter shaft 90 protruding from a hole 180 , where the hole can located off to one side of the head 20 . The putter head 20 can include an easily retrievable and storable ball marker 50 , and removable portions such as a front face 80 and top removable portion 30 for allowing advertising indicia, logos, and the like, to be placed thereon.
For storing the ball marker 50 , a cavity type compartment 130 that can have an oblong shape can be located in the bottom 120 of the putter head 20 . The cavity 130 can have an opening groove-shaped cut-out in the lower part of the rear(back) 126 of the putter head 120 , and the cavity 130 can have closed sidewalls 138 . The entire lower surface of the cavity 130 can be completely open. The cavity 130 can be located so that the marker 50 is substantially located under the main center of mass(center of gravity) of the putter head 120 , so that leaving the marker 50 during play does not offset the balance of the putter head 120 . A permanent magnet 170 can be located in an indentation in the ceiling surface of the cavity 130 .
The player can slide the marker 50 through the side opening 132 until the marker 50 is resting against the inner curved sidewalls of the cavity 130 which is also where the full force of the magnet 170 can then hold the marker 50 , such as a metal ball marker in place. Alternatively, the player can position the marker over the main part of the cavity 130 so that the attraction force of the magnet 70 just pulls the marker 50 in place.
When the player needs the ball marker 50 , the player can take their finger, such as a thumb and slide the ball marker 50 out of cavity 130 toward the opening 132 until the attraction of the magnet is no longer in effect.
The putter head 120 can also have an upper cavity type compartment 150 that can be used to support a logo plate 30 , such as a square logo plate therein, so that advertising indicia is visible from above the putter head 120 . The upper logo plate 30 can also be metal, and can be removably held in place by an optional magnet 155 . Additionally, the logo plate 30 can have other indicia such as names and addresses of the owner of the putter personalized thereon.
Across the front face 128 of the putter head 120 can be another advertising/logo plate 80 . Inside of the putter head 120 can be another compartment 140 that supports a weight 60 such as a lead weight therein. The weight 60 can be removable if the player desires different weights to be used with the putter head 120 . Across the front outer face of the weight 60 can be the second advertising metal plate 80 that can also be held in place by an optional magnet 65 that can be attached on the outer face of the weight. The magnet 65 can allow for different logo plates 80 to be removably attached thereon.
Although magnets are described that can hold the logo plate 30 and advertising plate 80 , thereon, other types of fastening arrangements can be used. For more permanent attachments, glue or adhesive can be used.
On top of the putter head 120 can a sight line 100 substantially down the middle between the front face 128 and rear face 126 of the putter head 120 .
Slidable Marker Field by Tracks
FIG. 15 is a top front perspective view of another embodiment of the novel putter head 20 . FIG. 16 is a top rear perspective view of the putter head 20 of FIG. 15 . FIG. 17 is a bottom front perspective view of the putter head 20 of FIG. 1 . FIG. 18 is a bottom rear perspective view of the putter head 20 of FIG. 1 FIG. 19 is a bottom front perspective view of putter head 20 with ball marker 50 removed. FIG. 20 is a front view of the putter head 20 of FIG. 15 . FIG. 21A is a rear view of the putter head with detail of T-Slot ball marker holder compartment 110 . FIG. 21B is an enlarged view of the T-slot ball marker holder compartment 110 of FIG. 21A . FIG. 22 is a left side view of the putter head 20 of FIG. 15 . FIG. 23 is a right side view of the putter head 20 of FIG. 15 FIG. 24 is a top view of the putter head 20 of FIG. 15 . FIG. 25 is a bottom view of the putter head of FIG. 15 with ball marker 50 in T-Slot holder compartment 110 . FIG. 26 is a bottom view of the putter head 20 of FIG. 25 with ball marker 50 removed from T-Slot holder. FIG. 27 is a top front exploded view of the putter head 20 of FIG. 15 . FIG. 28 is a bottom front exploded view of the putter head 20 of FIG. 15 .
Referring to FIGS. 15-28 , the second embodiment can include similar parts as in the previous embodiment with the exception of utilizing a disc shaped logo plate 40 that can also be held in place by a magnet in side of the cavity 160 of the supporting the disc shaped plate 40 therein. In addition, the second embodiment 20 can have a T-slot shaped cavity type compartment 110 that can have track shaped edges that can grip about side edges of the ball marker 50 . Although a preferred ball marker 50 can be metal, the T-shot shaped tracks can be sized tight enough so that the edges of nonmetal(such as plastic) ball markers, can be held in place. Also, a magnet 70 can be used with the T-slot shaped cavity compartment in order to more carefully secure the ball marker 50 in place. With the T-slot shaped cavity, the user generally must slide the marker into the cavity through the lower rear back side opening 132 of the cavity 130 . The removal can be similar to the previous embodiment where the user slides the marker out of the cavity toward the opening 132 .
Although the preferred embodiments refer to the golf club being a putter, the invention can be used with other types of golf clubs, such as drivers, woods, and the like.
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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Devices, apparatus, and methods of storing and releasing a ball marker from the bottom of a head of the golf club, such as a putter. A compartment in the bottom of the golf club head has a side opening adjacent to the rear of the golf club head for allowing a disc shaped ball marker to be slid into the compartment, and sliding the marker in reverse allows the marker to be slid out of and removed from the compartment. A magnet can also be used. Also, the compartment can have grooved side walls that act as tracks to allow the marker to be slid into and out of the compartment. A removable top disc and front plate on the golf club head allows for advertising indicia and logos to be placed on the head of the golf club.
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BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to the methods of making liquid nitrogen-sulfur fertilizers for direct application to the soil. Liquid fertilizer has come into wide-spread usage in locations where irrigation rather than rainfall is predominantly used to irrigate crops, such as California. Liquids are readily introduced into the irrigation systems and do not clog pipes or valves. With the relatively recent advent of drip irrigation, the problem of clogging small diameter openings is severe.
The reaction between urea and concentrated sulfuric acid is categorized as follows: ##STR1##
The reaction is strongly exothermic and explosion may result if concentrated sulfuric acid is used without dissipating the heat. The resulting end product is a liquid which remains in the fluid state at most temperatures. This liquid fertilizer is ideally suited to the relatively new methods of drip irrigation.
2. Brief Description of the Prior Art
Previous patents teach methods of making liquid fertilizer, for example, Jones, U.S. Pat. No. 4,116,664, describes a sequential method of slowly adding sulfuric acid to powdered or prilled urea in order to control the resulting heat of the exothermic reaction. by blending in small amounts over a tortuous path through a multi-stage reactor, a liquid nitrogen -sulfur fertilizer is gradually produced. The slowness of this method is commercially impractical for producing large amounts of liquid fertilizer. Moreover, the capital investment for the reactor is substantial in relation to the volume of fertilizer produced.
Garthus, et al. U.S. Pat. No. 3,984,226 relates to a process wherein sulfuric acid reacts with ammonia gas to form a liquid. The considerable amount of equipment, i.e., holding tanks, absorbers, etc., used under this process requires substantial capital outlays. Neither of these processes of the prior art teaches the making of a liquid fertilizer by mixing urea and sulfuric acid in a quick, simple and economic batch process in which the heat of the reaction is effectively controlled.
The reaction of urea and sulfuric acid is so highly exothermic as to present a danger of explosion. Consequently, the prior processes either: (1) greatly diluted the ingredients to make a fertilizer of very low nutrient levels for the quantities packaged and shipped; or (2) very slowly prepared a concentrated fertilizer to avoid explosion. Both of these alternatives are uneconomical.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention provides a quick, simple, economical method for producing a concentrated liquid nitrogen sulfur fertilizer by dissipating the heat of reaction in a heat sink. The heat sink may conveniently be any nutritive component that absorbs sufficient heat of reaction to eliminate the risk of explosive reaction. In a preferred embodiment, the heat sink may be the already reacted liquid fertilizer. Thus, by leaving a "heel" of about 10% of the fertilizer from the previous batch in the mixing tank, the heat is dissipated as the reaction takes place in the tank, which also acts as a reaction vessel.
This method thus overcomes the explosive heat of the prior art. It also does this without the need for any complex processing machinery.
It is an object of this invention to provide an improved method of making a concentrated liquid nitrogensulfur fertilizer.
It is a further object to rapidly mix concentrated sulfuric acid with urea without explosion.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the preferred embodiment, a conventional mixing tank is provided, having a suitable agitator for thorough mixing and reaction. A suitable size is 6500 gallons. Means for removing the final liquid product froom the tank is included, such as a tap at the bottom of the tank. Inlet means, such as a three inch pipe which, for example, has a flow rate of 1,500 lbs./minute, may be used to introduce liquids to the tank. Because concentrated sulfuric acid is used, all hardware should be made of 316 stainless steel or its equivalent.
In order to minimize the amount of fertilizer to be transported, the highest values of N and S in the final product is desired. Another goal is to have the fertilizer in liquid form for ease of application. Given these competing considerations, a commercially practicable upper limit on these values is about 28 units nitrogen and about 9 units sulfur. If the fertilizer has nitrogen content below 26 parts or a sulfur content below 4 parts, it is not as commercially desirable as the above recited levels. While lower concentrations are produceable and utilizable, the optimum levels for readily transportable, highly concentrated, liquid nitrogen-sulfur fertilizer fall in the range of 26-0-0-4 to 30-0-0-10. While urea is about 46% nitrogen, it is in solid form. Maximum concentration of these two nutrients is obtained by reacting the solid urea with concentrated sulfuric acid and a minimum of water as diluent.
A fertilizer with a 28-0-0-9 composition has 28 parts nitrogen, no phosphorous or potassium, and 9 parts sulfur. This fertilizer is made according to the present invention by combining a greater than stoichiometric amount of urea, having high N value, with cooncentrated sulfuric acid. This combination is explosive if the acid is added at 1,500 lbs./minute. The urea should be at least 50% of the end product and sulfuric acid should be at least 10%.
The process of this invention involves placing a heat sink into the mixing tank. In order to provide the highest values of nutrients in the fertilizer, the heat sink should add to the nutritive properties of the fertilizer and not merely dilute it. The heat sink must be capable of absorbing a large quantity of quickly evolving heat from the reaction.
In the preferred embodiment, between 5 and 20% of the weight of the end product is a heat sink made of a previously produced batch of liquid fertilizer having the same proportions of starting products as the desired fertilizer. If a 28-0-0-9 fertilizer is desired, then the following amounts of ingredients are further added: 61% urea, 30% H 2 SO4 and the balance, water.
The calculation is as follows. Urea, providing the N component, is 46% nitrogen. To give a final value of N of 28, then (28/.46)=61% urea must be included in the reaction (apart from the nutritive heat sink). Similarly, to give a fertilizer with 9% sulfur, using sulfuric acid at 93% concentration (about 30% sulfur), then (9/.30)=30% sulfuric acid in the reaction. The remaining 9% of the mixture apart from the heat sink is conveniently water. More water may be added, of course, but the nutrient values of the end product are correspondingly reduced. For commercial purposes, I prefer not to exceed 15% water in the end product.
While higher concentrations of sulfuric acid are available, e.g. 98%, I prefer 93% concentration for the optimum balance of economy and effectiveness. While lower concentrations of sulfuric acid may also be used (e.g. 60%) the resulting product is more diluted, and does not achieve the particularly high concentrations of nutrients in a liquid fertilizer as does the 28-0-0-9 formula.
The heat sink of the reacted fertilizer from a previous batch, as in the preferred embodiment, does not dilute the concentration, yet it absorbs sufficient heat of reaction to avoid the risk of explosion. Where the previous batch of fertilizer is used as the heat sink, at least 5% of the weight of the end product is needed to provide reasonable assurance of safety from excessive heat or explosion. There is no theoretical upper end to the amount of heat sink retained in the mixing tank but beyond 20% of the weight of the new batch consisting of recycled fertilizer, the benefit is no greater so there is no need to recycle more than that.
The heat sink must be intimately mixed with the solid urea to prevent explosion. Using a heat sink of previously made liquid fertilizer and agitations, a slurry of urea, water and liquid fertilizer is prepared before adding the sulfuric acid. Care should be taken to avoid masses of solid urea because concentrated sulfuric acid is highly reactive with solid urea. The heat sink should thoroughly permeate the urea.
As a specific example, 10% of recycled fertilizer may be left in the container of the remaining 90% of the new batch to be made up of new ingredients, urea is added in an amount equal to about 55% by weight of the desired end product.
Then water is pumped into the mixing tank in an amount equal to about 8% by weight of the desired end product. Water helps to dissolve the urea.
Then 93% sulfuric acid is added in an amount equal to about 27% of the weight of the desired end product. The acid is added at a rate of about 100-500 gallons per minute, into the tank.
While the resulting fertilizer has only nitrogen and sulfur, other nutrients can readily be blended with the highly concentrated liquid. For example, potash, phosphoric acid, or zinc sulfate may be easily mixed with the present fertilizer to give a broaderr range of nutrients. An advantage of the fertilizer of the present process is its ability to be stored for long periods and under varying conditions. While there is a high N content, there is no free ammonia, a common source of instability with other liquid fertilizers.
Urea sulfate liquid fertilizer has been found to have a very low pH, e.g. 0.5 pH. Highly acidic fertilizers are very useful for treatment of alkaline soils, such as in California's Central Valley, where the soil pH ranges from approximately 7.5 to 9.5
The fertilizer produced by the process of this invention is easy to transpot and to apply to irrigation systems, including drip systems, as well as directly to the soil. It is highly concentrated to give the maximum nutrient values while maintaining a liquid formula. This desirable concentrated producct is achieved economically by absorbing the heat of reaction in a nutritive heat sink.
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A new improved process for making liquid fertilizer having a high nitrogen and sulfur content has been developed in which urea and sulfuric acid are mixed. Exothermic heat, which normally builds up in successive reactions is dissipated via use of a non-reactive, nutritive heat sink, preferably comprising a predetermined amount of previously produced fertilizer.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a method of separating closed bolls of cotton. More specifically, this method is for separating closed cotton bolls into different levels of maturity by means of specific gravity of the boll.
(2) Description of the Prior Art
Cotton dust has been a major problem in the cotton industry for several years. Numerous efforts have been devoted to solving the problem of dust in cotton gins as well as in textile processing operations. Cotton-related dust is suspected of causing a respiratory disorder (Byssinosis) in some individuals, but research has failed to identify a causative agent. A proposed method of identifying the causative agent has been to harvest large quantities of uncontaminated cotton. The uncontaminated cotton has been harvested in the closed-boll form in the field before it had opened and suffered weathering effects. Procurement of large quantities of lint cotton have been hampered by the inability of current technology to provide a means to separate the closed bolls of cotton by differences in maturity. Boll size is not directly related to boll maturity and thus can not be used as a means of separation. Previous researchers have found that about 40% of the bolls that were harvested in the field were immature and had to be discarded after they were conditioned and dried and had failed to open.
At present, the physical size of the boll, the color of the boll, and the location of the boll on the plant are used to estimate maturity. These factors, however, provide only a 60% efficiency.
After the closed bolls are dried and conditioned and have opened, the immature bolls can be discarded. However, no technology exists to allow separation of the somewhat opened or opened bolls into discreet levels of maturity. Maturity is directly related to micronaire and the cotton industry presently assigns no discounts to micronaire values of 3.5 to 4.9. Lint cotton having a higher or lower micronaire, however, is discounted.
SUMMARY OF THE INVENTION
The present invention provides a method for separating closed bolls of cotton into discreet levels of maturity after the bolls are harvested from the plant, but before they are conditioned and dried. This method will increase the efficiency of the boll selection process significantly. It is the unique feature of this invention to utilize the fact that the specific gravity of each closed boll decreases as the maturity of the boll increases. Thus, the separation of the closed bolls after harvest, as a function of specific gravity also separates the bolls into different levels of maturity. Selective separation of the closed bolls in liquid solutions having densities of less than 1 isolates the individual bolls into different levels of maturity. Thus, correlating the specific gravity readings of the unopened bolls of cotton with the moisture content of the bolls and subsequently translating the moisture content into known maturity dates of the cotton bolls can be relied upon as an accurate method for classifing unopened cotton bolls.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention deals with one of the major problems of closed-boll cotton concept, that is, cotton bolls are produced throughout a long growing season. Past experience has shown that the highest seed germination level is from 42-day-old bolls whereas fiber maturity is established somewhat eariler. If unopened bolls are to be harvested from presently used varieties, they should be between 40 and 50 days old to have acceptable fiber and seed maturity. Bolls begin to open after 50 days of age under most cultural and environmental conditions, and current closed-boll harvesting equipment removes all of the bolls from the cotton plant at one time with a finger-stripper or brush-stripper. Therefore, some of the bolls are extremely immature (less than 10 days old) while some of the bolls are fully mature or opened if the bolls are transported directly to the gin after harvesting. Therefore, the closed bolls are separated from the plant parts and opened bolls. It is the separation of closed bolls of cotton by maturity with which this invention deals. This separation cannot be done manually because maturity is not closely correlated to boll size, shape or color. Since the size of a cotton boll increases exponentially during the first 10 days after anthesis and reaches maximum at about 25 days and since the weight of the seed cotton in the boll increases exponentially during the first 10 days after anthesis and reaches a maximum at about 25 days, there is a critical and limiting time frame in which to harvest the optimum closed cotton boll.
Therefore, the following general classification of harvested closed cotton bolls was made:
Artifically dry and separate the closed bolls into well-opened, moderately opened and unopened categories. About 40% of the bolls were in the unopened category. Micronaire readings for the well-opened and unopened bolls were taken and recorded at 3.6±0.5 and 2.8±0.4 respectively. Thus, the artifically opened bolls were separated into categories of maturity based upon the degree of opening.
However, the closed bolls presented a different problem. It is the discovery of this invention that micronaire correlates well with boll moisture content. Therefore, separation of maturity of closed bolls can be accomplished by accurately measuring the moisture content. Since the specific gravity of the closed boll is a direct function of the maturity of the boll, then classification by means of specific gravity measurement is possible. This is valid because the moisture content of the boll changes rapidly as it matures while the boll size developes early and remains relatively constant. Very immature bolls are comprised of over 90% water. As the boll begins to mature the moisture content of the boll decreases until such time that it reaches about 60% and begins to open. Once the boll begins to open, the lint and seed begin to equilibrate with the existing environmental conditions and the moisture content of the seed and lint fiber drops rapidly. The following examples of the preferred embodiments show the validity of the inventive concepts claimed herein.
EXAMPLE 1
The specific gravity of individual closed bolls of known age was measured as follows.
White blooms were tagged on three separate occasions-July 16, 24, and 30, 1980 for four varieties of cotton-Stoneville 213, Coker 420, Deltapine 61 (DPL 61), and DES 56. Bolls were harvested at three ages-27, 33, and 41 days. After the bract, peduncle and calyx were removed, the specific gravity of each boll was determined by Archimedes' principle. Since the specific gravity of closed bolls is less than 1, they float in water. To compensate for this problem, a 50 g brass sinker-weight was attached to the boll and caused the boll to submerge in water (Black and Little, 1956). The specific gravity was then calculated from the following equation:
Specific gravity=W.sub.o /(W.sub.1 -W.sub.2)
where
W o =Initial boll weight, g,
W 1 =Boll weight plus sinker weight (submerged in water), g, and
W 2 =Boll weight (sumberged in water) plus sinker weight (submerged in water), g.
Each boll was also assigned a specific gravity level as defined in Example 2. The bolls were then opened by hand and dried at 38° C. for 48 h.
Example 1 was conducted in a completely random design with three replications and two factors-variety (four levesl) and age (three levels). Analysis of variance was performed for seven dependent variables: initial weight, moisture content, specific gravity, major diameter, minor diameter, length, and specific gravity level. Micronaire readings were determined from the combined lint fiber for the three replications. Analysis of variance was conducted at the 5% level of probability and Duncan's multiple range test (DMRT) was used to separate the means where necessary. Physical dimensions were measured with micrometers.
RESULTS AND ANALYSIS OF EXAMPLE 1
Values for the dependent variables in the study are given in Table 1. Means for the moisture content of the bolls were 67.16, 72.54, and 75.37 percent, respectively for boll ages of 41, 33, and 27 days. The moisture content of the closed bolls decreased as the age of the boll increased. Specific gravities for boll ages of 41, 33, and 27 days were 0.9045, 0.9309, and 0.9351, respectively (Table 1).
Variety as a source of variation was significant for all dependent variables (Table 2). Boll age significantly affected moisture content, length and specific gravity. Interactions between variety and boll age were not significant for the dependent variables.
Since the specific gravity and moisture content were significantly affected by varieties and boll ages, the specific gravity separation for maturity technique should only be used within a variety. This is further substantiated by the micronaire readings shown in Table 1. Separation of the varietal means indicated that the specific gravity of Stoneville 213 was not different from that of DPL 61. In addition, the specific gravity of Coker 420 was not different from the specific gravity of DES 56. Although the levels of specific gravity required for accurate separation of closed bolls as a function of maturity differ, the same levels may be used for several varieties without a significant loss of precision.
Results of Example 1 suggest that the major diameter are primarily a function of boll variety, but not of boll age. The boll length dimensions were a function of variety and boll age as well as the interaction between variety and boll age. Consequently, boll size is not a good estimate of boll maturity. Initial boll weights were significantly different for the varieties, but not for the boll ages, thus, varietal differences must be considered in any separation system.
TABLE 1__________________________________________________________________________MEANS FOR THE DEPENDENT VARIABLES FOR EXAMPLE 1.sup.1 Tag Boll Initial Moisture Major Minor Specific Date age, Weight, Content, Diameter, Diameter, Length, Gravity Specific MicronaireVariety 1980 days Grams Percent cm cm cm Level Gravity Reading__________________________________________________________________________Stoneville 7-16 41 11.71 68.87 2.76 2.64 3.48 7.3 0.9109 4.2213 7-24 33 14.85 72.58 3.00 2.90 3.72 5.0 0.9500 3.8 7-30 27 14.14 75.15 3.00 2.90 3.00 5.0 0.9571 2.8Mean 13.57 a 72.20 a 2.92 a 2.81 a 3.40 a 5.8 a 0.9393 a 3.6 aCoker 420 7-16 41 17.21 67.20 3.09 3.00 4.30 7.0 0.9030 4.2 7-24 33 18.97 72.55 3.31 3.05 4.06 6.3 0.9262 3.2 7-30 27 20.48 76.65 3.35 3.23 4.41 7.0 0.9180 2.5Mean 18.89 b 72.13 a 3.25 b 3.10 b 4.26 b 6.8 b 0.9157 b 3.3 aDPL 61 7-16 41 17.07 66.12 3.52 3.16 4.53 6.0 0.9344 5.5 7-24 33 15.63 70.61 3.82 2.86 3.01 4.7 0.9405 3.7 7-30 27 13.58 72.10 2.92 2.70 3.67 4.7 0.9568 3.2Mean 15.43 a 69.61 b 3.41 bc 2.91 a 3.74 c 5.1 c 0.9439 a 4.1 bDES 56 7-16 41 11.44 66.44 3.18 2.69 3.09 9.0 0.8698 4.6 7-24 33 12.80 74.41 2.91 2.76 3.44 7.7 0.9070 3.0 7-30 27 12.05 77.58 2.88 2.63 3.57 6.7 0.9085 2.6Mean 12.10 ac 72.81 a 2.99 d 2.69 a 3.36 a 7.8 d 0.8951 b 3.4 a__________________________________________________________________________ .sup.1 Harvested from field 5 at the Delta Branch Experiment Station, Stoneville, MS on August 25, 1980. Means within each column not followed by the same lowercase letter were significantly different at the 5% level of probability as judged by Duncan's multiple range test.
TABLE 2__________________________________________________________________________ANALYSIS OF VARIANCE FOR THEDEPENDENT VARIABLES IN EXAMPLE 1 Degree MEAN SQUARES FOR of Initial Moisture Major Minor SpecificSource Freedom Weight Content Diameter Diameter Length Gravity__________________________________________________________________________Variety (A) 3 77.39.sup.1 18.10.sup.1 0.09.sup.1 0.07.sup.1 0.19.sup.1 0.005.sup.1Boll Age (B) 2 4.38.sup.2 208.96.sup.1 .03.sup.2 0.01.sup.2 0.12.sup.1 0.003.sup.1A × B 6 7.44.sup.2 5.46.sup.2 .03.sup.2 0.02.sup.2 0.08.sup.1 0.001.sup.2Error 24 11.40 6.00 .01 .02 .03 0.001__________________________________________________________________________ .sup.1 Indicates significance at the 5% level of probability. .sup.2 Indicates nonsignificance at the 5% level of probability.
EXAMPLE 2
The following flotation method was used to separate bolls into increments based on their specific gravity; premixed solutions of liquids with different specific gravities were used to divide bolls into several different groups:
Methanol and water were mixed in varying quantities to obtain 11 distinctly different specific gravities. The specific gravities (at 25° C.) used ranged from 0.7840 which is the specific gravity of the undiluted methanol to 0.9970 which is the specific gravity of the undiluted distilled water. The specific gravities of the solutions were as follows:
______________________________________Specific Gravity Level Specific Gravity______________________________________1 0.99702 0.97823 0.95644 0.93465 0.91286 0.89107 0.86928 0.84799 0.826610 0.803811 0.7840______________________________________
Specific gravity of each solution was monitored periodically with a hydrometer and methanol was added when necessary.
One hundred closed cotton bolls of unknown ages were harvested from four varieties and two field locations on four separate harvest dates. All of the bolls were removed from randomly selected plants. The peduncles, bracts and calyx were carefully removed in the laboratory. Each boll was then dropped sequentially into the premixed solutions beginning with the highest specific gravity level, level 1. Surface moisture was removed from each boll with a paper towel before the boll was dropped into each solution. When a boll failed to float, it was classified as having a specific gravity midway between that of the two solutions. The bolls were then cracked open and dried in a laboratory oven at 38° C. for 48 hours. The identity of the bolls by specific gravity level, variety, field location and harvest date was maintained throughout the process. After the bolls were dried to a moisture content of about 10%, the cotton was removed from the burr by hand and ginned on a small gin. The lint fiber was then conditioned for 24 hours at 21° C. and 65% relative humidity, and divided into 3.24 g-subsamples to obtain the micronaire reading. The micronaire was measured with a Sheffield Micronaire instrument.
Data were then analyzed as a randomized complete block, split plot experimental design with field locations as blocks. Four varieties, four harvest dates, six levels of specific gravity, and two locations were used. Insufficient numbers of bolls were separated in specific gravity levels 1, 2, 3, 10, and 11 to allow them to be included in the analyses. Consequently, bolls that were separated in specific gravity levels 4, 5, 6, 7, 8, and 9 were used. Means were separated where necessary with DMRT at the 5% level of probability. The only dependent variable used was micronaire.
RESULTS AND ANALYSIS OF EXAMPLE 2
Values of micronaire as a function of specific gravity for each variety and location are shown in Table 3. Means of the micronaire reading for all varieties and field growing locations increased progressively from 3.02 to 4.33 for specific gravity levels of 0.9455 to 0.8379 respectively. Since mean values for micronaire increased progressively as the specific gravity decreased, closed cotton bolls can be separated by differences in the specific gravities of the bolls.
Analysis of variance for micronaire was performed for the data as a split plot, randomized complete block design. Since subunit error terms were not significantly different from the whole unit error terms, the error terms were pooled. Analysis of variance was subsequently performed as a randomized complete block, factorial design. The effect of variety and specific gravity on micronaire was significant at 1% level of probability. Harvest date was not significant. DMRT for varieties indicated the following significance:
______________________________________Variety Micronaire______________________________________DPL 61 4.03 aStoneville 213 3.70 bCoker 420 3.23 cDES 56 3.19 c______________________________________
The levels of specific gravity of 0.9455, 0.9327, and 0.9019 did not produce significantly different levels of micronaire as shown below:
______________________________________Specific gravity Micronaire______________________________________0.8379 4.33 a0.8592 4.02 b0.8801 3.57 c0.9019 3.23 d0.9237 3.03 d0.9455 3.02 d______________________________________
Thus, the number of levels of specific gravity could be reduced to four.
Micronaire readings for the interaction between varieties and harvest dates were significant (Table 4). This suggests that the rate of maturity differs for the varieties since micronaire is an estimate of maturity. Micronaire readings for the interaction between variety and specific gravity were also significant. The significant interaction indicates that micronaire readings from the closed bolls separated by the same levels of specific gravity differ with varieties. Consequently, in order to precisely separate closed bolls by maturity, different levels of specific gravity must be used for different varieties. Lack of significance between the means for the micronaire reading for Coker 420 and DES 56 suggests that some varieties can be separated with the same levels of specific gravity. The interaction between variety, harvest date and specific gravity was significant. The interaction contributed a comparatively small amount to the mean squares and has little practical significance.
The coefficient of variability was 13.5% which suggests an acceptable degree of variability within the data.
Cotton grown in location 2 produced higher micronaire readings than did the cotton grown in location 1 for nearly all levels of specific gravity (Table 3). The only exception was the Stonevill 213 variety at a specific gravity level of 0.8379. Mean values for micronaire for locations 1 and 2 were 3.42 and 3.67, respectively.
Some immature bolls were separated into the levels of specific gravity that yielded relatively mature bolls. Apparently, the relationship between specific gravity and maturity is somewhat hyperbolic in that the same specific gravity level exists early and late in the development of the external boll size and the high moisture content of the undeveloped seed and fiber within the boll that is present at that time. The seed and lint continue to grow and mature long after the boll size has reached its maximum.
The cotton marketing industry currently uses values of micronaire from 3.50 to 4.90 without assessing a discount. With this in mind, closed bolls with a specific gravity of about 0.88 should produce lint fiber with a micronaire value 3.5 or above (Table 3). Further analysis of Table 3 suggests that this is also true for the mean for all varieties; however, each variety has a different relationship between specific gravity and micronaire.
Analysis of variance (Table 4) indicated that the micronaire was significantly different for varieties, locations, and levels of specific gravity. Differences due to specific gravity were highly desirable. Differences due to variety and location, however, support the conclusion that each variety and growing location require a slightly different level of specific gravity to separate closed bolls strictly as a function of a given micronaire reading. The data do suggest that generalized divisions between levels of micronaire can be achieved simply by a flotation method that separates the bolls as a function of their specific gravity.
TABLE 3__________________________________________________________________________MICRONAIRE AS A FUNCTION OF VARIETY,FIELD LOCATION & SPECIFIC GRAVITY EXAMPLE 2 Micronaire for specific gravityVariety Location.sup.1 0.9455 0.9237 0.9019 0.8801 0.8592 0.8379__________________________________________________________________________Stoneville 213 1 3.00 3.08 2.98 3.72 4.28 4.54Stoneville 213 2 3.16 3.05 3.94 3.90 4.76 4.21Coker 420 1 2.98 3.12 2.72 2.88 3.38 3.84Coker 420 2 2.72 2.59 2.98 3.27 4.04 4.23DPL 61 1 3.32 3.35 3.88 4.40 4.06 4.67DPL 61 2 3.32 3.52 4.15 4.43 4.55 4.83DES 56 1 2.78 2.86 2.58 2.73 3.24 3.82DES 56 2 3.02 2.97 2.67 3.25 3.88 4.63Mean.sup.2 -- 3.02 a 3.04 a 3.24 a 3.57 b 4.02 c 4.33 d__________________________________________________________________________ .sup.1 Locations 1 and 2 were fields 1 and 9, respectively, at the Delta Branch Experiment Station, Stoneville, MS. .sup.2 Means not followed by the same lower case letter were significantl different at the 5% level of probability as judged by Duncan's multiple range test.
TABLE 4______________________________________ANALYSIS OF VARIANCE FOR THEMICRONAIRE VALUES FOR EXAMPLE 2Source Degrees Sum Probabilityof of of of GreaterVariation Freedon Squares F-Value F______________________________________Variety (V) 3 23.10 33.72 0.0001.sup.1Harvest date (H) 3 1.65 2.41 0.0705.sup.3Specific gravity (S) 5 47.03 41.19 0.0001.sup.1V × H 9 12.00 5.84 0.0001.sup.1V × S 15 6.96 2.03 0.0205.sup.2H × S 15 2.44 0.71 0.7680.sup.3V × H × S 45 16.28 1.58 0.0311.sup.2Replication 2 2.81 12.30 0.0007.sup.1Error 95 21.69______________________________________ .sup.1 Indicates significance at the 1% level. .sup.2 Indicates significance at the 5% level. .sup.3 Indicates lack of significance at the 5% level of probability.
EXAMPLE 3
Cotton bolls were grown under irrigated conditions, and separated into increments based on their specific gravity with the same flotation technique as in Example 2 since bolls used in Examples 1 and 2 were produced on plants in non-irrigated fields.
The primary purpose of Example 3 was to establish the relationship between specific gravity and maturity for bolls produced under irrigated conditions in one growing location and from one variety of cotton. White blooms on cotton plants from variety DES 56 were tagged on Aug. 6, 1980. Twenty-five of the tagged bolls were harvested on each day for Sept. 4, 11, and 17, 1980. The bracts, peduncles and calyx were removed by hand and the specific gravity was determined with the flotation method described in Example 2. Data was analyzed using a one-way analysis of variance with three levels of age (29, 36, and 42 days) and 25 replications. The analysis was performed for three dependent variables-initial weight, specific gravity level, and moisture content. Means were separated with DMRT at the 5% level of probability.
RESULTS AND ANALYSIS OF EXAMPLE 3
Means and the analyses of variance for the initial weight, specific gravity level, and moisture content are given in Table 5 for the data collected in Example 3. The mean moisture content for the bolls harvested at 29, 36, and 42 days of age was 70.51%. The moisture content was significantly different for boll ages and was 75.09, 69.37, and 67.08% for ages 29, 36, and 42 days, respectively. Specific gravity levels were also significantly affected by boll age. The specific gravity levels followed the same pattern as did the moisture content values. Specific gravity levels were 6.84, 7.76, and 9.12, respectively, for ages 29, 36, and 42 days. The analysis suggests that for a particular variety of cotton grown in a particular field under irrigated growing conditions, the specific gravity method may be used to separate closed bolls into maturity groups on the basis of moisture content.
TABLE 5______________________________________ANALYSES OF VARIANCE AND MEANS FOR INITIALWEIGHT, SPECIFIC GRAVITY LEVEL, AND MOISTURECONTENT FOR EXAMPLE 3MEANS AND MEAN SQUARES FORSource Specificof Initial Weight Gravity Level Moisture ContentVari- Mean Mean Meanation.sup.2 Mean.sup.3 Squares Mean.sup.3 Squares Mean.sup.3 Squares______________________________________Boll 16.91 55.22.sup.1 7.91 32.89.sup.1 70.51 425.83.sup.1Age29 16.30a 6.84a 74.09aDays36 18.61b 7.76b 69.37bDays42 15.83a 9.12c 67.08cDaysEr- 7.44 1.90 8.27ror______________________________________ .sup.1 Significant at the 5% level of probability. .sup.2 Degrees of freedom were 2 and 72, respectively, for boll age and error. .sup.3 Values not followed by the same lowercase letter were significantl different at the 5% level of probability as judged by Duncan's multiple range test.
SUMMARY AND CONCLUSIONS OF RESULTS
Emphasis on the procurement of closed bolls to provide clean cotton necessitated a method for separating closed bolls into different maturity classes. Since the moisture content of closed bolls correlates with the maturity of the fiber and seed, separation of closed bolls based on their specific gravity is demonstrated.
In Example 1 the specific gravity, physical dimensions, moisture content and micronaire were established for four varieties. In Example 2 all the bolls from selected plants of four varieties and two field locations were harvested and separated with solutions of known specific gravity. In Example 3, the effect of soil irrigation on the specific gravity and maturity of closed bolls was considered.
Results show conclusively that cotton bolls can be separated by specific gravity into discrete levels of maturity of micronaire. These micronaire levels are a function of variety. However, if resolution is sacrificed somewhat and the micronaire increments are appropriately selected, then the method is acceptable. For example, if specific gravity levels of 0.95, 0.90, 0.88, and 0.84 are used to separate closed bolls, micronaire readings should be less than 2.3, 3.1±0.4, 3.6±0.6, and 4.2±0.5, respectively. These levels are valid for at least four varieties and two growing conditions. In order to obtain greater resolution, the specific gravity method of separation must be modified somewhat for each variety of cotton.
It should be understood that the invention should not be limited to the means of obtaining the specific gravity of the flotation solutions in the example given (the addition of methanol to water). Any means can be used which will produce the same desired result.
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A method for separating/classifying closed bolls of a given variety of cotton by maturity is disclosed. Harvested, unopened cotton bolls are immersed in a series of solutions having a specific gravity of less than one. The bolls of cotton are thus identified and separated by means of the different specific gravity readings. The specific gravity readings are correlated with the moisture content of the bolls and subsequently the maturity dates of the cotton. Additional steps for cleaning, washing and drying are provided as needed. Alcohol/water solutions are utilized to prepare solutions with specific gravities of 0.8379 to 0.9455.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to semiconductor switching circuits and more particularly to a circuit for optimizing the switching speed of a high-voltage semiconductor switching device, such as a high-voltage transistor.
(2) Brief Description of the Prior Art
The use of a semiconductor device, such as a transistor, in the switching mode involves a compromise between the speed of switching, the maximum voltage to be handled by the transistor and the maximum current to be passed by the transistor. In general, the higher the voltage and current handling capacity of a transistor, the lower the switching speed available from such a device.
In certain applications, such as switching-mode power supplies, there is a requirement for switching circuits which are capable of operating at high speed. Where it is desired to provide a high power output from such a supply, it will be seen that the switching circuits must be able to handle high voltages and currents as well as operate at high speeds.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a switching circuit using a semiconductor switching device of inherently low speed whose switching speed is increased by virtue of the circuit, without the need to provide a reverse drive for removing charge stored in the device, and wherein the circuit is capable of operation over a wide range of switched currents.
In accordance with the invention there is provided a semiconductor switching circuit for switching current from a power source through a load in response to switching control signals applied thereto; the circuit comprises first and second switching devices connected in series to switch the current through the load. The first switching device may have a higher voltage rating but lower inherent switching speed than the second switching device, both switching devices being responsive to the control signals applied thereto to switch together. A voltage limiting means is arranged to limit the voltage across the second switching device so that its voltage rating is not exceeded and also so as to remove stored charge in the first switching device, thereby increasing the switching speed of the circuit.
It will accordingly be seen that the first switching device is chosen for its high voltage handling capability, the second switching device being chosen for its switching parameters. Since the voltage limiting means sets a maximum to the voltage presented across the second device, the operational voltage rating of the second device may therefore be very low compared to that of the first device. A circuit may be designed in accordance with the technique utilizing high current handling devices and such a circuit will provide rapid switching at high voltage and currents.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages will become apparent from a study of the following specification, when viewed in the light of the accompanying drawing, in which:
FIGS. 1 and 2 are electrical circuit diagrams of two switching circuits of the prior art;
FIG. 3 shows a circuit diagram in accordance with one embodiment of the invention;
FIG. 4 shows a circuit diagram in accordance with a second embodiment of the invention; and
FIG. 5 shows a circuit diagram in accordance with a third embodiment of the invention.
DETAILED DESCRIPTION
Various circuits have been previously proposed for improving semiconductor switching speeds, two such circuits being shown in FIGS. 1 and 2 of the accompanying drawings.
FIG. 1 shows a known circuit which is sometimes referred to as the Baker clamp. An N.P.N. switching transistor 10 is connected in series via its collector and emitter with a load 11 and this series combination is connected across a power source 12. Input switching signals are applied to terminals 13 and pass through three diodes 14, 15, 16 connected in series as shown, to the base of transistor 10. A fourth diode 17 is connected between the junction of diodes 14 and 15, and the collector of the transistor 10.
In operation, base current for turning transistor 10 on is applied to the terminals 13. The base current is maintained until collector saturation of the transistor is just about to occur. Any increase in current through the diode 14 will be diverted by the diode 17 away from the base of the transistor and into its collector. The turn-off time of transistor 10 is thereby minimized due to the clamping action of diode 17. The disadvantage of this circuit is that this clamping action is only usable over a limited range of collector currents, and that the available improvement in switching speed is limited.
FIG. 2 shows a circuit utilizing a further previously proposed method for improving switching speeds, known as a reverse bias turn-off circuit. A transformer 20 is provided with input terminals 21 connected to its primary winding. The base of a P.N.P. transistor 22 is connected to one terminal of the secondary winding of the transformer 20, and also to the emitter of transistor 22 via a diode 23 and a resistor 24 connected in series. The emitter of transistor 22 is also connected to the base of an N.P.N. transistor 25 which provides a switched path for a load 26 in series with its collector and emitter across a power source 27. A further terminal of the secondary of the transformer 20 is connected via a diode 28 to the collector of transistor 22. A tap on the secondary winding is connected to the emitter of transistor 25 and, via a capacitor 29 to the collector of transistor 22.
In operation, an input switching signal is applied to the terminals 21 and a resultant forward drive pulse from the secondary winding of the transformer 20 charges the capacitor 29 via the diode 28 negatively with respect to the emitter of the transistor 25. The cassation of the drive pulse switches transistor 22 on, which thereby connects the base of transistor 26 to a negative base-emitter voltage provided by the charge on capacitor 29. This negative voltage produces reverse base drive to remove the charge stored in the base-emitter junction of switching transistor 25, and thereby to minimize the turn-off time of the transistor 25. The disadvantage of the circuit of FIG. 2 is that the removal of stored charge is dependent upon the forward drive amplitude of the pulse to the transistor 25, and is limited to a reverse bias voltage that should not exceed the reverse breakdown voltage for the base-emitter junction of the device chosen for transistor 25. Furthermore, the need to provide a reverse base drive for removing the base-emitter stored charge leads to an increased number of components--e.g., the transformer 20.
FIG. 3 shows a circuit diagram of a switching circuit arranged to switch current from a power source 30, which may be a high voltage source, e.g. 300 V, through a load 31. The power source 30 is connected across a series combination of the load 31, a first N.P.N. transistor 32 and a second N.P.N. transistor 33, each of the transistors providing a switched path between their respective collectors and emitters. A switching generator 34 includes terminals 34a, 34b, 34c for providing switching signals as described hereafter. The terminal 34a is connected to the base of transistor 32 via a diode 35 and a resistor 36 connected in series, and to the base of transistor 33 via a parallel combination of a capacitor 37 and a resistor 38. The base of transistor 33 is also connected to its emitter via a resistor 39. The terminal 34b is connected via a resistor 40 to the base of a third N.P.N. transistor 41 having its collector connected via a resistor 42 to the base of transistor 32, and having its emitter connected to the emitter of transistor 33 and to the terminal 34c.
A commutation diode 43 may be connected in parallel with the load 31 as shown and a capacitor 44, which may have a value of 10 μF for a 300 V power source, may be connected across the power course 30.
The first transistor 32 is chosen to have high voltage and current handling ability, whilst the second transistor 33 is chosen to have a high current rating and fast switching parameters. With a power source of 300 V, the voltage rating of the transistor 33 need be no more than a few tens of volts.
In operation, the switching generator 34 is arranged to provide antiphased switching signals at terminals 34a and 34b as shown by the outputs Q and Q. If terminal 34b is positive with respect to terminal 34c and terminal 34a is at zero, transistors 32 and 33 are off and transistor 41 is on. The polarities of terminals 34a and 34b are now reversed for a finite time t. Transistors 32 and 33 are switched on allowing current to flow through the load 31, and transistor 41 is switched off. Where the impedance of load 31 has an inductive component, the collector current risetime of transistor 32 is relatively unimportant.
At the end of time t, the polarities of terminals 34a and 34b return to their original states (i.e. terminal 34a zero, terminal 34b positive) and transistor 41 is turned on whilst transistor 33 is turned off. The emitter current of transistor 32 falls to zero at a rate determined by the fall time of the collector of transistor 33 and the transistor 32 is effectively held on during this time by the stored charge in its base region. Once transistor 33 has turned off, the voltage at the emitter of transistor 32 would normally rise and therefore necessitate transistor 33 having a high voltage rating. However, in the illustrated circuit, the collector current of transistor 32 is now diverted into flowing through its collector-base capacitance and via resistor 42 and transistor 41 which is turned on. Resistor 42 is made small enough to prevent the voltage of the base and hence that of the emitter of transistor 32 rising above the maximum rating of transistor 33. The resistor 42 and transistor 41 thereby comprise the above-mentioned voltage limiting means.
Upon the cessation of this collector-base current in transistor 32, the transistor can be regarded as turned off. The fall time of the collector current of transistor 32 is therefore determined by the collector-base capacitance of transistor 32, the impedance of the load 31, the value of the resistor 42, and the effective saturated-on resistance of the transistor 41.
The diode 35 is used to block the reverse base current of transistor 32 and prevents this current from attempting to once more switch on transistor 33 via resistor 38.
As an alternative to the transistor 41 and resistor 42, the voltage limiting means may comprise any suitable clamping device such as a low voltage avalanche or zener diode connected in similar fashion and preventing excess voltage from being present at the base of transistor 32. FIG. 4 shows a circuit in accordance with such an embodiment of the invention, which circuit is identical to that of FIG. 3 with the exception that transistor 41 and resistor 42 are replaced by a zener diode 46 connected between the base of transistor 32 and the emitter of transistor 33 so as to limit the voltage appearing at the base of transistor 32. As a result, switching generator 34' need only provide one phase of switching signal at terminal 34a, and accordingly terminal 34b and base resistor 40 of the FIG. 3 circuit are not included in this embodiment.
Operation of the FIG. 4 circuit is similar to that previously described with reference to FIG. 3. However, in this case the voltage limiting effect is provided only at the voltage of zener diode 46, which should be set to be no greater than the voltage rating of transistor 33. At the cessation of the switching pulse from switching generator 34', transistor 33 commences to turn off and current that was flowing from the collector to the emitter of transistor 33 now flows through the collector-emitter capacitance of transistor 32 to start removing the charge from the base of transistor 32. This action is more beneficial to the transistor 32 than, for example, the charge removal accomplished by the prior art circuit shown in FIG. 2 since it almost completely prevents reverse bias second breakdown of transistor 32.
Upon the removal of the base-emitter charge of transistor 32, the collector-base junction of this transistor goes into its reverse-recovery mode of operation which is very rapid since this action can be likened to the reverse-recovery action of the P-N junction of a diode. The turn-off time of transistor 32, and hence of the switched load current path, is thereby substantially decreased.
A similar technique may be used for other semiconductor switching devices such as field effect transistors (F.E.T.s).
FIG. 5 shows a circuit in which one F.E.T. is used as the high speed switching device, the switching operation of the other switching device being somewhat different to that of FIGS. 3 and 4. Components common to these figures have the same reference numerals. The switching generator 34' provides switching signals through resistor 38 to the gate electrode of a FET 53 (specifically an n-channel enhancement type MOSFET). Resistor 39 is connected between the gate and the source of FET 53. The power source 30 is connected across a series combination of load 31, N.P.N. bi-polar transistor 32 and FET 53. A current transformer 55 may be included at any point in this series combination and its purpose will be explained hereafter.
The base of transistor 32 is connected to a drive arrangement, different to that of FIGS. 3 and 4, in the form of zener diode 46 connected as previously described and a capacitor 56 connected in parallel with the zener diode 46. A D.C. drive circuit 57, which may receive an output of the current transformer 55, if this transformer is included, provides D.C. drive to the base of transistor 32 via a diode 58 and a resistor 59 connected in series.
In operation, only F.E.T. 53 receives switching signals directly from the switching generator 34', transistor 32 being responsive to these signals indirectly by virtue of the change in condition at its emitter. Assuming that conditions are quiescent and that in the absence of a switching signal from generator 34', F.E.T. 53 is off, the base of transistor 32 is at a voltage determined by the leakage current of zener diode 46 (which may alternatively be any other clamping device as discussed previously) and the corresponding voltage drop across resistor 59. For present purposes, it is assumed that drive circuit 57 provides a constant D.C. drive. The gate of FET 53 should be below its threshold voltage and held at this level by the generator 34'.
A positive pulse (switching signal) from the generator 34' to the gate of FET 53 rapidly turns on the FET, pulling the emitter of transistor 32 down towards the reference potential (i.e. that of terminal 34c). This action causes a large current of flow from the capacitor 56, which had previously been charged to the potential of zener diode 46, into the base of transistor 32 driving the transistor into saturation. Base current of transistor 32 is maintained via diode 58 and resistor 59 and is adjusted to keep transistor 32 in saturation. Automatic adjustment may be provided by circuit 57 configured as a proportional drive circuit, which provides D.C. drive proportional to the switched load current. In this case inclusion of current transformer 55 will provide a current-representative signal to circuit 57, which may then include a rectifier/storage capacitor arrangement for producing a peak-current representative drive to transistor 32 from the current-representative signal of transformer 55. Such an arrangement would provide an averaged peak-current drive. Alternatively, an instantaneous peak current drive may be preferred. In any event the drive should include a basic minimum constant D.C. component, even at zero switched load current, plus a component varying in accordance with variation of load current.
When the switching signal from generator 34' is terminated, FET 53 commences to turn off and current that was flowing from the drain to the source of FET 53 now flows through the collector to emitter capacitance of transistor 32 to start removing the charge from its base in a similar manner to that described with reference to FIG. 4.
It will be seen that capacitor 56 charges from the drive circuit 57 via resistor 59 when FET 53 and hence transistor 32 is off. When FET 53 turns on, and hence the potential at the emitter of transistor 32 drops, the capacitor discharges via the base of transistor 32, saturating the transistor. However, since charge can also flow into the capacitor from the base of transistor 32 when FET 53 is turning off, and hence transistor 32 emitter potential is rising, it is envisaged that under certain operating conditions, this charge may be sufficient subsequently to provide the corresponding discharge, and hence the D.C. drive circuit 53 may be dispensed with.
In the circuit of FIG. 5, the FET is used as the fast switching device, and a bi-polar transistor as the other switching device. Although this is a particularly advantageous configuration, making use of the fast switching speed of FETs, any combination of either or both bi-polar transistors or FETs may be used. Where an FET is used as transistor 32, the circuits described are particularly advantageous, as it is known that FETs have a parasitic bi-polar transistor effect which introduces a dV/dt limitation to the rate of rise of the source. This becomes a problem at high switching speeds, and ultimately may lead to self-destruction of the device, as a result of the reverse bias second breakdown effect. The removal of charge from the base of transistor 32 (whether bi-polar or FET) as described above prevents this effect and therefore leads to increased reliability in operation.
Although the switching generators 34, 34' are shown as discrete elements, they may readily be constituted by any means for providing suitable base drive switching signals, such as the feedback winding(s) of an inverter transformer in a switching-mode power supply. In certain applications, for example the half-bridge inverter, more than one switching means is required and consequently as many of the switching circuits may be provided as are necessary to switch current through the load.
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A semiconductor switching circuit is disclosed which switches current from a power source through a load in response to switching control signals applied to first and second semiconductor switching devices, such as transistors. The first and second transistors are connected in series and the first transistor has a higher voltage rating but lower switching speed than the second transistor. A voltage limiting device, such as a further transistor, effectively limits the voltage across the second transistor so that its voltage rating is not exceeded and also so as to remove stored charge in the base region of the first transistor which would otherwise tend to hold the transistor on. This technique increases the switching speed of the circuit and allows a high voltage and current handling device to be selected for the first transistor, and a high current, high speed device to be selected for the second transistor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/272,286, filed Nov. 17, 2008, which issued as U.S. Pat. No. 7,731,542 on Jun. 8, 2010, which is a continuation of U.S. patent application Ser. No. 11/195,412, filed Aug. 2, 2005, which issued as U.S. Pat. No. 7,452,245 on Nov. 18, 2008, and claims the benefit of U.S. Provisional Application No. 60/598,640, filed Aug. 4, 2004 and U.S. Provisional Application No. 60/637,247, filed Dec. 17, 2004, which are incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
The present invention relates generally to electrical connectors, and more particularly, to a modular communication jack design with an improved wire containment cap.
BACKGROUND OF THE INVENTION
In the communications industry, as data transmission rates have steadily increased, crosstalk due to capacitive and inductive couplings among the closely spaced parallel conductors within the jack and/or plug has become increasingly problematic. Modular connectors with improved crosstalk performance have been designed to meet the increasingly demanding standards. Many of these connectors have addressed crosstalk by compensating at the front end of the jack, i.e., the end closest to where a plug is inserted into the jack. However, the wire pairs terminated to the insulation displacement contact (“IDC”) terminals at the rear portion of a jack may also affect the performance of the jack.
One problem that exists when terminating wire pairs to the IDC terminals of a jack is the effect that termination has on the crosstalk performance of a jack. When a twisted pair cable with four wire pairs is aligned and terminated to the IDC terminals of a jack, a wire pair may need to flip over or under another wire pair. An individual conductor of a wire pair may also be untwisted and oriented closely to a conductor from a different wire pair. Both of these conditions may result in unintended coupling in the termination area which can degrade the crosstalk performance of the jack. Thus, a solution addressing the crosstalk in the termination area of the jack would be desirable. This solution should produce a termination that is as noiseless as possible to minimize the crosstalk of that termination.
A second problem that exists when terminating wire pairs to the IDC terminals of a jack is variability. A technician is typically called on to properly terminate the wire pairs of a twisted pair cable to the proper IDC terminals of the jack. Each jack terminated by the technician should have similar crosstalk performance. This requires the termination to remain consistent from jack to jack. However, different installers may use slightly different techniques to separate out the wire pairs and route them to their proper IDC terminals. Thus, a solution that controls the variability of terminations from jack to jack would be desirable.
A final issue that arises when terminating wire pairs to the IDC terminals of a jack is the difficulty of the termination process. Typical jacks provide little assistance to the technician, resulting in occasional misterminations (e.g. a wire being terminated at an incorrect location in the jack). Even if detailed instructions are provided with the jack, technicians may not read these instructions prior to installing the jacks. Furthermore, a jack with a difficult termination process can increase the installation time for the technician and result in a costly installation for the customer. Thus, a jack solution that simplifies the termination process and minimizes the possibility of technician error would be desirable.
SUMMARY
The present application meets the shortcomings of the prior art by providing a wire containment cap having a first side including a plurality of retainers for retaining wires, a second side being opposite the first side, two sidewalls extending between the first side and the second side, a support rib extending between the two sidewalls and including two pair separators for separating a pair of wires, and a plurality of sloped pair separators located between two of the retainers and including a sharp point for cutting through insulation material on a pair of bonded wires.
A communication jack assembly is also described. The communication jack comprises a front portion including a retention clip, and a wire containment cap including a retention recess for securing the wire containment cap to the front portion. The wire containment cap comprises a first side including a plurality of retainers for retaining wires, a second side being opposite the first side, two sidewalls extending between the first side and the second side, a support rib extending between the two sidewalls and including two pair separators for separating a pair of wires, and a plurality of sloped pair separators located between two of the retainers and including a sharp point for cutting through insulation material on a pair of bonded wires.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front upper right perspective view of a communication jack having a wire containment cap in accordance with an embodiment of the present invention;
FIG. 2 is a front upper right partial-exploded view of the communication jack of FIG. 1 ;
FIG. 3 is a front upper right perspective view of a wire containment cap in accordance with an embodiment of the present invention;
FIG. 4 is a rear upper left perspective view of a wire containment cap in accordance with an embodiment of the present invention;
FIG. 5 is a rear isometric view of a wire containment cap in accordance with an embodiment of the present invention, showing cross-sections 6 - 6 and 7 - 7 ;
FIG. 6 is a cross-sectional view of a wire containment cap taken across cross section 6 - 6 from FIG. 5 , in accordance with an embodiment of the present invention;
FIG. 7 is a cross-sectional view of a wire containment cap taken across cross section 7 - 7 from FIG. 5 , in accordance with an embodiment of the present invention;
FIG. 8 is a conceptual diagram illustrating a wire pair alignment of opposite ends of a typical twisted pair cable with one example of an IDC terminal layout;
FIG. 9 illustrates diagrams 300 of six alternate IDC terminal layout arrangements along with the corresponding wire containment cap design for each of the arrangements. The diagrams 302 , 304 , 306 , 308 , 310 , and 312 merely provide examples of different terminal layouts for IDCs 1 - 8 and different wire containment cap designs, but these diagrams do not comprise all of the possible design options available;
FIG. 10 is an upper right perspective view of a wire containment cap in accordance with an embodiment of the present invention; and
FIG. 11 is a lower left perspective view of a wire containment cap in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a front upper right perspective view of a communication jack 100 in accordance with an embodiment of the present invention. The communication jack 100 includes a front portion 102 and a wire containment cap 104 . The front portion 102 may include such components as plug interface contacts, a mechanism for coupling the jack to a plug, crosstalk compensation circuitry, and wire-displacement contacts to provide an electrical connection between the jack and a communication cable. Additional details on the wire containment cap 104 are described with reference to FIGS. 3-7 , below.
FIG. 2 is a front upper right partial-exploded view of the communication jack 100 of FIG. 1 . In the embodiment shown, the wire containment cap 104 is slidably mounted within the front portion 102 . A retention clip 105 on the front portion 102 and a retention recess 108 on the wire containment cap 104 may be included to secure the wire containment cap 104 to the front portion 102 . Other mounting and securing techniques may also be used.
FIGS. 3-7 illustrate the wire containment cap 104 in further detail, in accordance with an embodiment of the present invention. The wire containment cap 104 includes a large opening in the back to allow a cable to be inserted, and allow the pairs to separate quickly as they transition toward IDC terminals. The opening consists of four individual quadrants with a spine 110 between pairs to minimize cable interaction. In addition to the retention recess 108 described above with reference to FIG. 2 , the wire containment cap 104 includes a shoulder 106 , a spine 110 , two pair separators 112 , a support rib 114 to support each pair separator 112 , upper wire retainers 116 , and lower wire retainers 118 . FIGS. 3-7 illustrate additional details as well, such as a possible frame shape for the wire containment cap 104 . In a preferred embodiment, the wire containment cap 104 is constructed of a plastic material, such as polycarbonate. Alternative materials, shapes, and subcomponents could be utilized instead of what is illustrated in FIGS. 3-7 .
The shoulder 106 serves as a support and stopping mechanism to place the wire containment cap 104 in a correct physical position with respect to the front portion 102 shown in FIGS. 1 and 2 . Alternative support and/or stopping mechanisms could also be used, such as one located on the front portion 102 , or on the wire containment cap 104 in such a position that it abuts an interior location in the front portion 102 , rather than the exterior abutment shown in FIGS. 1 and 2 .
The pair separators 112 are supported by the spine 110 and support rib 114 , and are positioned generally perpendicular to the support rib 114 . The pair separators 112 are advantageous because when the wire pairs are aligned with the IDC terminals, at least one wire pair will typically have to flip over or under the other pairs on at least one end of a twisted pair cable. One reason this flip may occur is because the wire pair layout on one end of a twisted pair cable is a mirror image of the wire pair layout on the opposite end of the twisted pair cable. Another reason this flip may occur is because the Telecommunications Industry Association (“TIA”) standards allow structured cabling systems to be wired using two different wiring schemes. Finally, a flip may occur because not all cables have the same pair layout.
The relatively open design of the wire containment cap 104 shown in FIGS. 3-6 is due in large part to the spine 110 and support rib 114 being relatively thin. This open space allows a technician to more freely move wire pairs and individual wires within the wire containment cap 104 to make any required flips or bends. To complete the installation, the technician need only place wire pairs on the appropriate sides of the pair separators 112 , secure individual wire pairs in the upper and lower wire retainers 116 , 118 , and attach the wire containment cap 104 to the front portion 102 .
FIG. 8 is a conceptual diagram 200 illustrating the wire pair alignment of opposite ends of a typical twisted pair cable. The example shown is an IDC terminal layout designed to match a typical twisted pair cable when that cable is wired with the more commonly used 568 -B wiring scheme. In diagram 202 and diagram 204 , the wire pairs are aligned according to the 568 -A wiring scheme. Under 568 -A, the green wire pair of the twisted pair cable should be terminated to IDC terminal ( 1 , 2 ), the orange wire pair should be terminated to IDC terminal ( 3 , 6 ), the blue wire pair should be terminated to IDC terminal ( 4 , 5 ), and the brown wire pair should be terminated to IDC terminal ( 7 , 8 ). Diagram 202 illustrates the 568 -A alignment of the wire pairs on one end of the twisted pair cable where the blue wire pair and the brown wire pair must be flipped in order to terminate those wire pairs to the appropriate IDC terminals. Diagram 204 illustrates the 568 -A alignment of the wire pairs on the other end of the twisted pair cable shown in diagram 202 . The wire layout in diagram 204 is a mirror image of the wire pair layout in diagram 202 and therefore different pairs are flipped. Diagram 204 shows the green wire pair and orange wire pair being flipped in order to terminate those wire pairs to the appropriate IDC terminal.
Diagram 206 and diagram 208 illustrate wire pairs aligned according to the more commonly used 568 -B wiring scheme. Under 568 -B, the alignment of the blue wire pair and the brown wire pair should not change from 568 -A but the orange wire pair should now be terminated to IDC terminal ( 1 , 2 ) and the green pair should now be terminated to IDC terminal ( 3 , 6 ). Diagram 206 illustrates the 568 -B alignment of the wire pairs on one end of the twisted pair cable where the wire pairs are matched to the IDC terminals and no wire pair flipping is necessary. Diagram 208 illustrates the 568 -B alignment of the wire pairs on the other end of the twisted pair cable shown in diagram 206 . The wire layout in diagram 208 is a mirror image of the wire pair layout in diagram 206 and therefore wire pairs are flipped. Diagram 208 shows the green wire pair being flipped with the orange wire pair and the blue wire pair being flipped with the brown wire pair in order to terminate those wire pairs to the appropriate IDC terminals.
Referring back to FIGS. 3-7 , the pair separators 112 are employed to minimize the interaction of wire pairs when they need to be flipped as described above. The separators 112 help to ensure that the wire pairs will only cross each other top to bottom or side to side, but not a combination of both.
The upper and lower wire retainers 116 , 118 are positioned to present the terminated wires to the front portion 102 , preferably in a perpendicular orientation to IDC terminals that may be included as part of the front portion 102 . In the illustrated embodiment, each wire retainers 116 , 118 includes an inner portion and an outer portion (wire restraining features), with an intermediate portion through which the IDC terminals may make electrical contact with the wire by piercing insulation on the wire to make a metallic contact. The inner and outer portions in essence serve as bridge supports on either end of the wire to allow the wire insulation to be pierced when the wire containment cap is pressed into the front portion 102 . The wire retainers 116 , 118 are preferably spaced at regular intervals to allow for consistent pair-to-pair separation. When utilized in combination with the spine 110 , pair separators 112 , and support rib 114 , improved electrical performance may be realized.
In typical operation, an installer may place a cable having an outer jacket diameter up to 0.310″ into the rear of the wire containment cap 104 and separately route each twisted wire pair (blue, green, orange, and brown) as appropriate. As a result, the wire termination process is simplified and electrical performance is improved over typical jacks. The outer jacket diameter may vary from one application to the next, depending on the particular standards in place, for example. Typical maximums are 0.250″ for Unshielded Twisted Pair (UTP) and 0.310″ for Shielded Twisted Pair (STP).
Wire containment cap 104 shown in FIGS. 3-7 was generally designed around an IDC terminal layout substantially similar to the IDC terminal layout in FIG. 8 . However, the techniques for wire pair separation utilized by wire containment cap 104 can be utilized generally to separate wire pairs in communication jacks with a variety of IDC terminal layout arrangements.
FIG. 9 illustrates diagrams 300 of six alternate IDC terminal layout arrangements along with the corresponding wire containment cap design for each of those arrangements. The diagrams 302 , 304 , 306 , 308 , 310 , and 312 merely provide examples of different IDC terminal layouts and wire containment cap designs, but these diagrams do not comprise all of the possible design options available.
FIGS. 10 and 11 illustrate an alternative wire containment cap 400 . In this alternative embodiment, the wire containment cap 400 includes a plurality of wire retainers 402 that each flex to allow a wide range of wire sizes to be inserted and held in place after insertion. A small barb on each of the wire retainers 402 retains the wires so that they may be clipped to remain in position until installation. This allows the same connector assembly to be used for multiple wire sizes, thereby improving ease of installation for the technician. The wire containment cap 400 also includes a plurality of sloped pair splitters 404 that assist in maintaining a constant number of twists on the cable end of a wire pair. Each sloped pair splitter 404 terminates in a relatively sharp edge between neighboring wire retainers 402 . This sharp edge can cut through insulation material holding bonded pairs together, allowing the wires to be placed into the wire retainers 402 without untwisting and pulling the wires apart by hand.
While certain features and embodiments of the present invention have been described in detail herein, it is to be understood that the invention encompasses all modifications and enhancements within the scope and spirit of the following claims.
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A wire containment cap includes a first side having a plurality of retainers for retaining wires, and a second side opposite the first side. Two sidewalls extend between the first side and the second side, and a support rib extends between the two sidewalls. The support rib includes two pair separators for separating wire pairs. In one embodiment, a plurality of sloped pair splitters is located between two of the retainers and includes a sharp point for cutting through insulation material on a pair of bonded wires. A communication jack assembly including a front portion and the wire containment cap is also described.
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BACKGROUND 1. Field Of The Invention
This invention relates generally to cardiovascular catheters of the type that include optical fibers for spectrometric determination of oxygen saturation or other chemical parameters of blood, and more particularly to a disposable calibration medium and shipping sleeve for such a catheter.
2. Prior Art
It has been recognized for some decades that such cardiovascular catheters of the optical type require calibration to compensate for variations in several parameters--particularly including transmission efficiency of fibers at multiple wavelengths, distance between fibers at the catheter tip, efficiency of optical connectors, and variations in gain of the detectors receiving back-scattered light from the fibers.
Therefore it is necessary to match a catheter to an electrooptical instrument, and calibrate the overall system as a unit. The catheter is connected to the instrument and the catheter tip exposed to a reference medium providing a known amount of back-scatter reflection; the instrument is calibrated; and the catheter then is separated from the reference medium and inserted into the fluid (usually blood) to be measured.
The historical technique for accomplishing the calibration step is to immerse the catheter tip into a reference liquid that contains suspended particles to reflect light back into the catheter. A standard used since the 1950s has been milk of magnesia--that is, a suspension of magnesium oxide.
This technique is subject to disadvantages. It is inconvenient to the user. It places severe sterility requirements on the calibrating liquid. It is hazardous to the patient or research subject, due to potential toxicity of traces of the liquid on the catheter when the catheter is subsequently placed in a living body. All these problems are attributable to the use of a liquid as the standard.
To avoid these problems Polyani et al. (U.S. Pat. No. 4,050,450) proposed using a hollow tube as a calibrating device. Conceptually this proposal has merit since it inherently avoids contact of the catheter tip with a liquid.
One of the present inventors, however, has tested this technique and found it objectionably imprecise--that is, not adequately repeatable. We cannot account entirely for the observed imprecision, though it is likely related to the difference between reflection properties of a smooth plastic wall and reflection properties of a particle suspension in a liquid medium such as blood.
Shaw et al. (U.S. Pat. No. 4,322,164) have described a calibration system using reflecting particles suspended in a transparent solid polymeric medium as an optical calibration standard. A spring presses the surface of the polymer against the catheter tip.
In the Shaw system, a latch mechanism holds the calibration surface out of contact with the catheter tip until the time for calibration. Then the user unlocks the latch mechanism (by actuating a release device manually through a sterile envelope), allowing the spring to push the calibration surface across a short gap into contact with the catheter tip.
Shaw's innovation represents an important step forward in this technology. His suspension of particles in a transparent solid medium offers substantial promise of simulating quite closely the reflection properties of blood. Shaw, like Polyani, avoids using a liquid as the calibration standard.
Thus the Shaw patent presents an ingenious and very useful solution to a knotty problem. Nevertheless that solution has its own drawbacks--particularly with regard to the mechanics of use--and so leaves considerable room for refinement.
These drawbacks will first be enumerated, and then discussed in detail. First, the Shaw device is needlessly elaborate mechanically. Secondly, it virtually prevents prechecking the calibration or even the general integrity of the optics after packaging but before final use.
Thirdly, Shaw's device is somewhat awkward in use because it must be actuated through the sterile container. Fourthly, it is subject to measurement errors that can arise from this procedure.
Finally, it places potentially conflicting requirements on the physical properties of the suspension medium. We will now take up each of these points in turn.
First as to the mechanical elaborateness or complexity of the Shaw device, that complexity includes providing:
(a) a movable gripper that holds the catheter in place by friction (after it is positioned within the overall device),
(b) a separate movable plunger that carries the calibration surface into contact with the catheter,
(c) a mechanical track along which the plunger can move (and it must move reliably),
(d) a spring for impelling the plunger along the track to bring the calibration surface into contact with the catheter tip with a reliably predetermined force,
(e) a latch to prevent the plunger from moving until desired, and
(f) a rocker arm that increases the lateral grip on the catheter at the last instant before the plunger is allowed to move.
All this must be accomplished without compromising the light-tight character of the entire unit, and of course without materially increasing the cost of the catheter.
Turning secondly to the desirability of prechecking calibration (or even prechecking the general operability of the optical-fiber subsystem): the Shaw invention deters such prechecking because the latch-release mechanism is designed to "fire" just once.
It would be desirable to have a means of verifying continuing integrity of the catheter if it remains in storage for a long time in the manufacturer's warehouse. Such verification, within the manufacturer's premises, could even include verifying stability of calibration, since the same instrument could be used for initial and all subsequent checks.
It would also be desirable to have a means of verifying continuing integrity of the catheter if it remains in storage for a long time in an intermediate wholesaler's warehouse. Here again, stability of calibration could be verified within that facility.
It would be even more desirable to have a means of verifying the integrity of a catheter upon arrival in the storeroom of the hospital or research facility where it is to be used. In this way the usability of a stock of catheters could be guaranteed against the rigors of long-distance shipment.
It is only very minimally useful to conduct such verifications when the catheters are drawn out of the storeroom for use, for at that point a timely replacement may be impossible. It will be understood that stability of calibration could be checked in this context as well.
In principle, for later reuse Shaw's plunger could be pulled back out and the latch reseated. Such a procedure, however, would be tricky to perform through the sterile container--at least without compromising the positional accuracy of the catheter tip in the calibration device.
That brings us to the third drawback: awkwardness in use through the sterile container. The Shaw device must be actuated by pressing in on the rocker arm, to increase the gripping force on the catheter and simultaneously release the latch that restrains the spring-loaded plunger.
As a practical matter, however, "pressing in on the rocker arm" in this context means squeezing the portion of the device where the rocker arm is accessible. Otherwise the entire device will simply slide away from the user's finger.
In order to squeeze the device, one must grip it between thumb and forefinger. Depending upon the initial orientation of the device in its package, this may require either that the user somehow position the thumb or forefinger (working through the sterile container) beneath the device, or that the device be rotated in its shipping tray so that the direction of motion of the rocker is generally horizontal.
Therefore the user must be very nimble-fingered, or the device must be held on the tray by a formed mount (yet another elaboration, and one that would increase the potential for damage during shipment), or in preparation for squeezing the rocker the user must rotate the device with the other hand, again through the sterile container.
During any of these operations, of course, there is a constant risk of rupturing the container and thereby exposing the catheter to contamination. It is not our intention to make more of this awkwardness than there is, but it will be apparent that use of the Shaw device is not completely without pitfalls.
The fourth drawback mentioned above is the potential for measurement error arising from the cumbersome manipulation of the calibration device through the sterile container. This is a more complicated matter to discuss.
On one hand, there may be means for mitigating the awkwardness of operation. Such means may include a reasonably reliable preorientation of the device in its package, and/or extraordinary dexterity on the part of the user. These factors may "save" the Shaw device from the inherent awkwardness discussed above.
Furthermore, awkwardness in use is in a sense self-limiting. The user can determine clearly--by direct visual observation, coupled with taking a calibration reading--whether he or she has been successful in releasing the latch.
On the other hand, such a "save" may yet leave a drawback that is even more problematical, due to being hidden. The user in fumbling with the device to rotate it into position for operation, or in the actual step of releasing the latch, may inadvertently damage either the calibration device or the catheter itself in one way or another.
For example, the free pivoting of the rocker arm may be impaired, the catheter-gripping device may be squeezed too tightly against the catheter, the cylindrical track in which the plunger operates may be deformed, or the plunger after release may be pushed too hard against the catheter tip. Although these consequences may all be unlikely, what is very likely is that if they do occur they will not be detected, and they will significantly alter the conditions of calibration.
The intermediate result is a concealed and probably systematic error in calibration--that is to say, one that will persist even if the calibration reading is continued for a protracted period, or even if several such readings are taken over a period of hours. The final result can be a serious misdiagnosis that has catastrophic effects for, e.g., a heart patient.
The final drawback introduced earlier is the placement of possibly conflicting constraints on the physical properties of the suspension medium. Shaw's patent suggests at several points--including the abstract and the claims--that the material must be, e.g., "compliant at the surface 14 and noncompressible" (column 4, lines 5 and 6).
These potentially inconsistent requirements are elsewhere expressed thus:
The mass of the reference element 17 should exhibit compliant characteristics at least at the surface to assure intimate optical engagement of the surface 14 of the reference element 17 with the ends or apertures of the optical fibers that are exposed at the distal tip 231 [of] the catheter 12. The incompressible characteristic of the mass is desirable to prevent changes in concentration of the uniformly dispersed particles 36 within the mass.
Yet another expression of the constraints on the suspension is this: "a solid medium that has a substantially incompressible body which is sufficiently compliant at its surface for intimate contact with the end of the light guide".
At the outset it is unclear whether an optimal calibration medium is nonuniform, or at least nonisotropic, in its properties--or whether it is possible for an entirely homogeneous substance to satisfy the requirements.
Shaw does not explain how much compliance "at the surface" can be accommodated before "changes in concentration . . . within the mass" become excessive. Compliance, after all, is not truly a "surface" phenomenon but necessarily implicates the "body" or "mass" of the material.
Shaw does advise one skilled in the art to use "[s]ilicone resins which cure to a substantially transparent, compliant and incompressible solid mass" (emphasis added). This specification seems clearly to aggravate, rather than circumvent, the paradox just described.
Part of the dual requirement on Shaw's calibration medium arises from the dual way in which he uses the medium: first percussively, and then quantitatively. In other words, Shaw's catheter tip and calibration surface first must both survive the impact between them, and then are expected to act as well-behaved components of a high-precision measurement system.
Since it is not feasible in current technology to compromise the rigidity of the optical fibers in the catheter tip, all of the accommodation must be provided in the calibration surface.
If that surface were hard, then (1) upon impact it or the tip could crack or shatter, and (2) after impact it might not conform well to the optical surfaces to ensure a "liquid-like" optical engagement. On the other hand if the calibration mass were soft, then upon impact it could compress and throw off the calibration.
In this way of looking at things, the problem arises due to the impact, and one wonders whether it could be avoided simply by shipping the apparatus with the latch already released. Shaw's device, however, is plainly designed on the assumption that such a solution is unacceptable.
Otherwise the latch and release mechanisms could be simply omitted. The same is even more apparently true of his device that increases the lateral grip on the catheter body at the instant the release mechanism is triggered.
Shaw does not explain, and we can only speculate, whether he even thought of this solution, or if so then why he discarded it. One possibility is that Shaw was concerned about the effects of constant force on the catheter tip or the calibration medium, or both.
His device employs a spring to "urge" the calibration surface against the catheter tip. In very protracted pressing of the standard surface against the tip, either the mass of the calibration standard or the nonoptical bulk of the tip itself--the portion surrounding the fibers--would be likely to deform significantly.
The result could be problems of calibration or operation, or both kinds of problems. Anticipation of such problems is thus one possible reason for Shaw's "last minute" release mechanism and procedure. That mechanism and procedure, however, are precisely what produce the several drawbacks already pointed out.
The five problem areas just discussed all arise from a "blind spot" in the Shaw approach. That blind spot is essentially a natural inclination to emulate in a new hardware context the prior wet methods of calibration.
A more sophisticated approach would recognize that such emulation is no longer necessary and would free the hardware configuration from purely historical constraints that produce the noted drawbacks. Such a solution would of course be highly desirable.
SUMMARY OF THE DISCLOSURE
Our invention is a disposable calibration medium and shipping sleeve for an optical catheter. The catheter is of the type that has a constriction near its tip. The catheter is further of a type that is adapted to project light from the interior of the catheter through the tip to the environment, and to receive light from the environment through the tip into the interior of the catheter.
The invention includes a body, and a cavity defined within the body to receive the tip of the catheter. The cavity fits sufficiently closely around the catheter to effectively prevent ambient light from reaching the tip.
The invention also includes some means for snapping into the constriction to gently retain the tip fully received within the cavity. For purposes of generality in expression we will refer to these means as "detent means." The detent means are defined within the cavity. They snap into the constriction only when the tip is received within the cavity fully.
In addition our invention includes some means for reflecting light that is projected outward from the interior of the optical catheter, back for reception into the interior of that same optical catheter.
These means, again for purposes of generality, we will call the "reflection means": they are within the cavity and generally facing the tip, in a mechanically and optically standardized relationship with the tip at all times--whenever the tip is fully received within the cavity.
The reflection means include a substance of standardized character and quality to provide a reflection standard for calibration. It will be noted that the substance is held passively in intimate contact with the tip of the catheter, without deforming stress.
Further, this condition continues (1) from the initial emplacement of the tip into the cavity of the calibration and shipping sleeve or boot (2) until the tip is removed from the sleeve for insertion into a patient's body.
Consequently the calibration of the tip may be performed as many times as desired, at any time between the initial emplacement and the eventual removal. In particular it may repeated, without the slightest inconvenience or compromise of reliability, at each waystation of shipment and at each benchmark of storage time, to maximize the likelihood of readiness for proper operation at the moment of use.
While the foregoing paragraphs may describe our invention in its most general terms, there are certain preferred features or characteristics which we consider advantageous to enhance the preparation or use, or both, of our invention.
In particular, we prefer that the substance be a substantially homogeneous suspension of reflecting particles in a material that is substantially translucent or transparent. The material is preferably a polymer, and preferably is molded with the suspended particles into a shape and size adapted to tightly grip the catheter.
We prefer that substantially the entire interior surface of the cavity be composed of the standardized substance. We also prefer that substantially the entire body be composed of the standardized subatance; in such a preferred form of the invention it may be advantageous to provide a separate external shell of a different substance--such as an opaque jacket.
As an alternative the entire body, including the interior surface but excluding the exterior surface, advantageously is composed of the standardized substance, and the exterior surface advantageously is substantially opaque.
Our invention also encompasses a method for shipping an optical catheter and preparing the catheter for operation. The method includes at least the following six steps.
One step is preparing a suspension of reflecting particles in an uncured polymeric material. Another step is causing to be prepared a mold that is shaped to form a body with a cavity that fits the catheter tip--sufficently closely around the catheter to effectively exclude ambient light from the tip.
Another step is placing the suspension in the mold. Yet another step is curing the polymeric material to form a body with a cavity of the character just described and to convert the suspension into a standardized reflecting substance for calibration of the tip.
Still another step is inserting the catheter tip into the cavity so that the tip enters and remains in a mechanically and optically standardized calibration juxtaposition with the standardized substance.
A final step is shipping the catheter tip and molded body together to a remote location for calibration and use; this step is performed while maintaining the standardized calibration juxtaposition.
By the use of this method, a user--upon receipt of the catheter at the remote location--can calibrate the catheter and tip using the standardized reflecting substance as it is already juxtaposed to the tip, and can then remove and discard the molded body to prepare the catheter for measurement use.
It is our preference, in regard to the method invention just described, that the causing and curing steps form the cavity to firmly grip the catheter--to obtain two advantageous results:
(1) during the shipping step, the catheter remains in stable position within the molded body to protect the catheter from shipping damage, and
(2) during subsequent calibration by the user, the standardized reflecting substance is held in standardized position relative to the tip for proper calibration.
The catheter and calibration boot or sleeve are readily sealed in sterilized condition into a protective envelope for shipment. In effecting such sterilized sealing preparatory to shipment, optical connections at the proximal end of the catheter may be left exposed for calibration.
This may be accomplished, for example, by sealing the closure of the envelope around the body of the catheter near its proximal end. An outer enclosure, preferably repetitively reopenable and resealable to allow repeated recalibration whenever desired, may be provided outside the envelope and enclosing the optical connections.
All of the foregoing operational principles and advantages of the present invention will be more fully appreciated upon consideration of the following detailed description, with reference to the appended drawings, of which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat schematic general view, not to scale, of a preferred embodiment of our invention in place on the tip of an optical catheter that is attached to a typical optical-catheter system apparatus.
FIG. 2 is a longitudinal section, which may be considered to be a plan or elevation view, of one preferred form of the FIG. 1 embodiment.
FIG. 3 is an end elevation of the same embodiment, taken from the open end of the boot or sleeve.
FIG. 4 is a longitudinal section, similar to FIG. 2, of another preferred form of the FIG. 1 embodiment.
FIG. 5 is an external side plan or elevation of the tip of a catheter for use with our invention.
FIG. 6 is an external end elevation of the same catheter tip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the disposable calibration sleeve and shipping boot 11 is positioned over the end (including the formed tip, FIG. 5) of an optical-type cardiovascular catheter 21. The catheter tip is inserted into the sleeve through an open end 18 and pushed in until it seats.
From comparison of FIGS. 2 and 5 it will be understood that there is a constriction 26 in the overall profile of the catheter 21, and that our invention provides a matching constriction 13, 14 in the internal wall of the sleeve/boot 11.
By "seats" we mean that the constriction 13, 14 in the internal wall of the sleeve 11 fits into the constriction 26 in the catheter. Preferably the fit is quite snug, so that the portion of the catheter tip distal to the constriction 26 is held in position firmly but gently.
Moreover, the internal dimensions of the distal end 15, 16 of the cavity 12 precisely match the external dimensions of the catheter tip--so that the extreme distal end of the catheter tip is held firmly but not forcibly against the end wall 16 (FIG. 2) of the sleeve 11.
The shape and size of the catheter constriction 25 can vary enormously with the design of the catheter 21. That design will in turn vary with the purposes for which the catheter is to be used, the size of the patient, and many other factors--not the least of which is the design philosophy of the manufacturer.
None of such variations is important to our invention, as long as (1) the catheter is of a type which has some constriction, though the constriction may be quite small, near its tip; and (2) the internal profile of the matching constriction inside our sleeve/boot 11 at least partially fits the constriction in the catheter.
Returning to FIG. 1, the proximal end of the catheter 21 typically is terminated in a connector manifold 22. Extending proximally from this manifold 22 are several individual hollow tubes and electrical extensions 23, and in particular a fiber-optic extension 24 with connector termination 25.
In use all of these several extensions 23, 24, 25 are connected to respective external devices for injecting or withdrawing fluids, electrical signals, and optical signals through the catheter. Of these several devices we illustrate in very schematic fashion only one that is particularly pertinent to the instant invention.
That is a device 43 which projects light through the optical-fiber means within the catheter 21 and out through the distal tips of those optical-fiber means. The device 43 also receives, detects and interprets light that is reflected back into the optical-fiber means from the environment of the tip.
By doing so the device 43 and the fiber-optic means within the catheter 21 cooperate to determine chemical characteristics (such as blood oxygen saturation) of that environment. As illustrated, the device 43 advantageously includes an optical-fiber means extension 42 of its own, terminating in a connector 41 that mates with the connector 25 from the catheter manifold 22.
Advantageously the catheter 21 after sterilization is enclosed for shipment in a sterile transparent bag 31, whose mouth is sealed by heat or otherwise along a marginal area 32. Preferably this marginal area is sealed around the fiber-optic extension 24, just distal to the fiber-optic connector 25--permitting passage of optical signals between the device 43 and the catheter tip, while maintaining a sterility-maintaining barrier 33 around the protruding fiber-optic extension 24.
The sterile bag 31 and protruding extension 24 and connector 25 are advantageously enclosed in a larger bag 34, which may preferably have a readily and repetitively reopenable and reclosable dust closure 36. This closure may, for example, be of the "snap locking" type.
In particular the closure 36 is advantageously of a type which can be opened only partially in a particular area, as at 37. Such a feature allows functional interconnection of the optical-fiber connectors 41 and 25 with minimal environmental exposure of the area near the sterility barrier 33 of the inner bag 31.
With suitable clean-room techniques, calibration can thus be checked any number of times without compromising the ultimate sterility of the catheter at use. This capability presents a real advance over the prior art.
Another advance over the prior art is that the person conducting a calibration need not handle the calibration boot/sleeve 11 through the bags 31, 34. The sleeve 11 is held with its internal calibration surface 16 (FIG. 2) securely but passively contacting the optical surfaces at the catheter tip, always ready for calibration.
Even a lengthy calibration-stability test of many hours or days could be performed without compromising the operability of the catheter in any way, should such a test become desirable.
The calibration boot/sleeve 11 may be of any convenient external shape, such as the cylindrical form illustrated in FIGS. 2 and 3. The cavity 12-16, accessible at only one end 18 of the body of the sleeve, has a proximal entrance section 12 that is cylindrical, if the exterior wall of the catheter is cylindrical.
Assuming the type of catheter tip illustrated in FIG. 5, the cylindrical entrance section 12 of the cavity may terminate in a conical section 13, which in turn leads to a cylindrical ledge 14 of substantially smaller diameter than the entrance section 12. Beyond this ledge 14 is a substantially spherical section 15. followed by a flat circular end wall 16.
The cavity constriction previously mentioned may now be seen to include not only the conical section 13 and the generally cylindrical ledge 13 but also the proximal portion of the spherical section 15. This constriction 13-15 and the constriction 26 (FIG. 5) near the catheter tip should fit together in such a way as to position the catheter tip very precisely adjacent to the reflectance standard surface 16.
Further, the boot/sleeve constriction 13-15, along with the body of the sleeve 11 generally, must be capable of deformation to permit the spherical tip section 27 of the catheter to pass through the constriction 13-15 of the cavity. Such passage is required for installation of the sleeve on the catheter--and again, upon application of mild tension between the catheter body and the sleeve 11, for removal of the sleeve immediately prior to use.
Within these constraints, however, the shapes of the cavity constriction 13-15 and catheter constriction 26 may depart very considerably. In particular, the constriction 13, 14, 15 need not fit all the way into the constriction 26 near the catheter tip, and their shapes need not be exactly complementary.
Other variables that are somewhat at the control of the designer, and which strongly affect the degree of match required or permitted, are the resiliency of the material 17 employed and the annular wall thickness of the cavity 12-16. The resiliency 17, however, in our design is primarily or even exclusively available for adjustment to the optimum value from the standpoint of optical coupling.
(Even the small forces that may be present with a very resilient calibration material can be avoided, if desired, by providing a small quantity of silicone oil or like optical-coupling substance between the catheter tip 136, F' and the calibration medium 16. The capability of such a substance to improve reproducibility in optical coupling by matching refractive indices is known.)
This very high degree of freedom to design the resiliency for optical optimization is another important advance which our invention offers. The significance of this advance will be particularly appreciated on review of the compromises that appear necessary in the prior art.
As shown in FIG. 4, if preferred a calibration boot and shipping sleeve 11' of our invention may be provided with an external shell 19. Such a shell may be used to improve opacity (for better exclusion of ambient light), mechanical security, or other properties as desired.
If desired the shell 19 may cover the proximal annular end 18' of the body of the sleeve, as illustrated. It may be either a chemical coating, as for example a kind of paint, or may be a separately formed element that is drawn or snapped into position over the material 17.
Although as mentioned earlier the thrust of our invention does not demand any particular kind of catheter, for reference it may be helpful to describe some features of one catheter tip with which our invention is particularly useful. FIGS. 5 and 6 represent the tip of such a catheter 21.
Fixed at the distal end of the catheter 21 are a molded tip 102 and an annular balloon 104. In the tip 102 is the polished distal end F' (FIG. 6) of a bundle of optical fibers that is drawn through a lumen in the catheter 21. Also in the tip 102 is a port or aperture D'.
This distal aperture D' effectively constitutes the distal end of another of the lumens in the catheter 21. The remaining space in the orifice of the tip is occupied with epoxy or like inert potting material 136.
As is well known in the cardiovascular field, a catheter of this general sort is inserted through the patient's vena cava into the right atrium and ventricle, with the tip 102 and its distal aperture D' extending onward into the patient's pulmonary artery. The tip 102 generally is held in that artery for pressure measurements there.
The balloon 104, as better seen in FIG. 5, is formed as a short length of latex tubing, positioned over a necked-down end section 131 of the catheter 21. The distal end of the balloon tubing 104 is doubled under and held by adhesive to the neck 103 of the tip 102.
The proximal end of the balloon tubing 104 is held by adhesive 135 to the proximal end of the necked-down end section 131, and the tapered annular space just proximal to the balloon is filled with epoxy or like cement. A very small balloon-inflation aperture B' is defined in the necked-down end section 131 of the catheter 101, communicating with the dedicated balloon lumen B.
From the point of view of our present invention, the most important feature of the tip of the catheter 21 is perhaps simply the constriction 26 that is formed at the neck 103 of the molded tip 102 proper. This constriction 26 lies between the doubled-under distal end of the balloon tubing 104 and the bulb 102.
The calibration boot or sleeve 11 of our invention is molded by injection or preferably (for greater control) compression from a two-part mixture--a base material and a reflective-particle filler. The filler is roughly one and one-half percent by weight of the mixture.
We are currently testing concentrations from one-quarter to one and one-quarter percent to determine the optimal value. It will be understood that this testing is straightforward. The criterion is reproducibility of the reflectance values obtained through the catheter. It is quite important that the concentration be uniform at the selected value.
The base material is advantageously a substantially transparent, medical-grade moldable high-strength silicone of durometer approximately thirty (using the scale known as "Shore A"). The filler is silica-free magnesium oxide (MgO) of ninety-nine percent purity, U.S.P. grade. It is obtained as a white powder with maximum particle size roughly one-thirtieth of a micron.
We have found it appropriate to provide three sizes of catheter--namely, diameters of five, six and seven "French". (The "French" is a customary unit of measure for catheter and needle diameters, one French being equal to a third of a millimeter.) Correspondingly the calibration sleeve/boot 11 of our invention is provided in three sizes.
In the smallest of these sizes, suitable with catheters designed for use with children, the diameter of the ledge 14 is 0.060 inch, that of the cylindrical entry section 12 of the cavity is 0.085 inch, that of the spherical portion 15 of the cavity is 0.073 inch, and that of the spherical, potting-material-filled end flat 136 is 0.025 inch.
The corresponding four values for a six-French catheter are 0.075, 0.120, 0.093 and 0.030 inch, and for a seven-French catheter 0.080, 0.120, 0.096, and 0.030 inch. Tolerances on these values are plus-or-minus approximately 0.003 inch, except for that on the cylindrical-section diameter--which may be 0.005 inch.
In all three sizes, the sleeve is one and a half inches long, and the center of the spherical portion 15 is at the center of the sleeve 11. The cone angle of the conical section 13 of the cavity is forty-five degrees plus or minus five degrees.
One vendor that is now able to produce such a molded part to specifications is Hi-Tech Rubber Inc., of Anaheim, Calif.
We prefer to provide a very precise abutment of the catheter tip and optical-fiber tips to the facing calibration surface. Recognizing, however, that there may sometimes be a slight positive clearance between the optically functional surfaces, we also prefer to provide a very small quantity of optical-coupling substance as a coating on the end structures of the catheter.
In particular, we consider it advantageous to add a one-percent solution of silicone oil in alcohol to such other liquid coating as may be applied on the distal structures of the catheter--e.g., to a heparin-complex solution that is often used to coat the balloon and pulmonary-artery distal aperture prior to shipment, to prevent formation of blood clots.
It will be understood that the foregoing disclosure is intended to be merely exemplary, and not to limit the scope of the invention--which is to be determined by reference to the appended claims.
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The catheter tip fits into a cavity in the boot and is held gently (in the longitudinal direction) by a detent formed within the cavity. A calibration substance faces the tip in a mechanically and optically standardized calibration relationship, to reflect light from within the catheter back into the catheter. The calibration substance is held in constant, precise contact with the tip--but passively, not by springs or other longitudinally forcible devices but by close fit between the tip and the precision-molded internal surfaces of the cavity. In the lateral direction the boot may tightly grip the tip, at a point where the optic fibers are protected against such force. To provide a reflection standard for calibration, the calibration substance is of standardized character and quality: it is preferably a homogeneous suspension of reflecting particles in translucent or transparent polymer. The entire boot is preferably compression- or injection-molded from the calibration substance, except for a rigid, opaque outer skin. The catheter is shipped to a customr with the boot in place, ready for calibration on receipt or whenever thereafter the catheter is to be used. After calibration the boot is removed and discarded.
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CROSS REFERENCE TO RELATED APPLICATIONS
NA
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
NA
BACKGROUND OF THE INVENTION
The present invention relates to aldehyde resins having low amounts of free aldehydes. More particularly the present invention relates to aldehyde resins formed in the presence of an amino acid. In the invention aldehyde resins refer to resins derived from the reactions of a phenol, urea, melamine or a mixture thereof and an aldehyde. Examples of aldehyde resins include phenol formaldehyde resins, urea formaldehyde resins, melamine formaldehyde resins, melamine-urea-formaldehyde resins, and the like. These resins are well known in the art.
Phenol formaldehyde resins were the first true synthetic resins to gain commercial acceptance early in the twentieth century. These phenolic resins are the product of the reaction between phenol and formaldehyde. Novalacs are acid catalyzed phenol formaldehyde resins where typically an excess of phenol used. Resoles are the base catalyzed reaction product of phenol and an excess of formaldehyde. In commercial production resoles are normally processed to a workable viscosity; then subsequently polymerized to high molecular weight polymers by simple heating. Urea formaldehyde resins are typically prepared by the condensation of urea and formaldehyde at a pH of between 4 and 7 and at a temperature close to boiling point. Melamine formaldehyde and melamine-urea-formaldehyde resins undergo condensation reactions with an aldehyde in a manner analogous to that of urea. U.S. Pat. No. 5,681,917 discloses a method of making melamine-urea-formaldehyde resins and is herein incorporated by reference.
A problem that exists with aldehyde resin systems is the amount of free formaldehyde that exists in the resins both during storage and upon cure. Formaldehyde is considered toxic and a carcinogen. The American Conference of Governmental and Industrial Hygienists has lowered its TLV to 0.3 ppm. Due to these health concerns much effort has been expended attempting to obtain aldehyde resins with reduced free formaldehyde levels.
An abstract of Japanese patent application 60149638 discloses the use of polyvinyl alcohol to reduce the odor from free formaldehyde in foams produced from resole type phenol-formaldehyde resins. U.S. Pat. No. 3,917,558 discloses the use of nitro compounds such as nitromethane to reduce the concentration of free formaldehyde in phenol-formaldehyde resins. U.S. Pat. No. 5,705,537 discloses the addition of a proteinaceous material, cysteine, glutamic acid, glycine, isoleucine, lysine, phenylalanine, serine tryptophan or mixtures thereof to a phenolic foam composition consisting of a phenol formaldehyde resole resin. The reference discloses the addition of the aldehyde reducing agent to the already formed resin. The use of melamine, urea and sodium sulfite have also been suggested for use as scavengers for formaldehydes. Some reduction in free formaldehyde concentration was noted in uncured resins where these scavengers were used, however during curing at high temperatures free formaldehyde levels increased over precure levels.
There are no suggestions in the art to utilize amino acids and in particular glycine to reduce the free formaldehyde in aldehyde resins by adding the amino acids to the reaction mixture of the aldehyde resin.
BRIEF SUMMARY OF THE INVENTION
The present invention describes aldehyde resins having reduced free formaldehyde. Particularly the invention relates to the use of amino acids to effectively reduce the amount of free aldehyde in the resins. More particularly the invention relates to the use of glycine as a component in aldehyde resins to reduce the free formaldehyde in aldehyde resins. The use of glycine in aqueous aldehyde resin systems also provides the added benefit of increased water tolerance over time.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
NA
DETAILED DESCRIPTION OF THE INVENTION
The present invention describes aldehyde resins having reduced amounts of free formaldehyde and methods of making the resins. In addition when glycine is added to the reaction mixture of an aqueous aldehyde resin system the resin especially resoles exhibit increased water tolerance over time.
The aldehyde resins for which amino acids will function to reduce free aldehyde include those aldehyde resins known in the art such as phenol formaldehyde, urea formaldehyde, melamine formaldehyde or melamine-urea-formaldehyde.
Phenols used in the preparation of phenol formaldehyde resins include one or more of the phenols which have heretofore been employed in the formation of phenolic resins and are not substituted at either the two ortho positions or at one ortho position and the para position. Such unsubstituted positions are necessary for the polymerization reaction.
Any one or all of the remaining carbon atoms of the phenol ring can be substituted. The nature of the substituent can vary widely and it is only necessary that the substituent not interfere with the polymerization of the aldehyde with the phenol at the ortho and/or para position. Substituted phenols employed in the formation of phenolic resins include alkyl substituted phenols, aryl substituted phenols, cyclo-alkyl substituted phenols, aryloxy substituted phenols, and halogen substituted phenols. The foregoing substituents can contain from 1 to 26 carbon atoms and preferably from 1 to 12 carbon atoms.
Specific examples of suitable phenols include 2,6-xylenol, o-cresol, p-cresol, 3,5-xylenol, 2,3,4-trimethyl phenol, 3-ethyl phenol, 3,5-diethyl phenol, p-butyl phenol, 3,5-dibutyl phenol, p-amyl phenol, p-cyclohexyl phenol, p-octyl phenol, 3,5-dicyclohexyl phenol, p-phenyl phenol, p-crotyl phenol, 3,5-dimethoxy phenol, 3,4,5-trimethoxy phenol, p-ethoxy phenol, p-butoxy phenol, 3-methyl-4-methoxy phenol, and p-phenoxy phenol. Multiple ring phenols such as bisphenol A are also suitable.
The urea used to prepared urea formaldehyde resins is available in many forms. Solid urea, such as prill, and urea solutions, typically aqueous solutions are commonly available.
The melamine used in the preparation of melamine and melamine urea formaldehyde resins may be totally or partially replaced with other aminotriazine compounds. Other aminotriazine compounds include substituted melamines, cycloaliphatic guanamines or mixtures thereof. Substituted melamines include alkyl melamines and aryl melamines which can be mono-, di- or tri-substituted. Examples of alkyl substituted include monomethyl melamine, dimethyl melamine, trimethyl melamine, monoethyl melamine and 1-methyl-3-propyl-5-butyl melamine. Examples of aryl substituted melamine include monophenyl melamine and diphenyl melamine.
Aldehydes used to react with the phenol, urea, melamine and combinations thereof have the general formula RCHO wherein R is a hydrogen or hydrocarbon radical having from 1 to 8 carbon atoms. Examples of aldehydes reacted with the phenol, urea, melamine or mixtures thereof include any of the aldehydes heretofore employed in the formation of aldehyde resins such as formaldehyde, acetaldehyde, propionaldehyde, furfuraldehyde, paraformaldehyde and benzaldehyde.
Suitable catalysts used to promote the reaction of the phenol, urea, melamine and mixtures thereof and the aldehyde are also present. Novalak type phenolic resins are typically prepared in the presence of strong acids such as sulfuric acid, sulfonic acid, oxalic acid or occasionally phosphoric acid. Novalak type resins may also be prepared using divalent metal catalysts containing Zn, Mg, Mn, Cd, Co, Pb, Cu, and Ni. Resole type phenolic resins are generally prepared in the presence of basic catalysts such as NaOH, Ca(OH) 2 and Ba(OH) 2 . Other basic catalysts such as triethyl amine may be used to prepare resoles. The catalysts may be used alone or as mixtures. The catalysts used in urea, melamine and melamine-urea formaldehyde resins are well known in the art.
Typically, a dual catalyst system is used to prepare urea, melamine, and melamine-urea resins. Initially the reaction is carried out in the presence of a basic catalyst and completed with an acidic catalyst. Basic catalysts include any of those listed above for preparing resoles. Acid catalysts include weak acids such as formic acid acetic acid and ammonium sulfate.
According to the invention an amino acid or mixture of amino acids is added to the aldehyde resin system prior to forming the resin as a means of providing reduced free aldehyde resins. Amino acids can be obtained by hydrolysis of proteins or synthesized in various ways, especially by fermentation of glucose. Examples of suitable amino acids include lysine, L-leucene and glycine. Glycine is a preferred amino acid. It has been found that as little as 1% by weight glycine based on the total weight of resin solids can reduce the level of free formaldehyde in aldehyde resins to less than about 0.1% by weight and substantially reduce the aldehyde emissions during the curing process.
Another advantage obtained by using glycine in water based aldehyde resin systems is the increased water tolerance with time. For example, water based resole resins when stored increase in viscosity and decrease in water tolerance over time. The use of glycine in water based resole was found to increase the viscosity and also increase the water tolerance with time. In general the advantages of glycine in an aldehyde resin can be obtained by adding from 1 to 3% by weight glycine based on the total weight of resin solids. Of course amounts greater than 3% by weight of an amino acid can be used but it is generally not economically desirable
In addition to the above components, other compositions known to those skilled in the art can be added to the aldehyde resins of the present invention. For instance, stabilizers and resin modifiers, emulsifiers, plasticizers and compounds to adjust the pH can be added.
Examples of stabilizers and resin modifiers include methanol, ethanol, isopropanol, borax, and sodium sulfite. Examples of emulsifiers include casein, whey, cellulose, gum and triethyl amine. Examples of plasticizers include glycols. Compounds used to adjust the pH of the aldehyde resins include alkali metals, alkali metal hydroxides, alkali metal carbonates, alkaline earth hydroxides, organic amines, dilute mineral acids and organic acids or acid salts.
The reduced free aldehyde resins of the present invention may be used in any application that comparable aldehyde resins were used. Examples include saturants for cellulosic materials, adhesives for bonding paper, textiles, leather, metals and elastomers, in abrasives, in the manufacture of particle board, as a binder for composite panels, etc.
Having thus described the invention the following examples are illustrative in nature and should not be considered as limiting the scope of the invention. In the examples all amounts were in parts by weight unless otherwise indicated. Initial viscosities were run at 25° C. on a Brookfield viscometer. The hot plate cure was conducted according to ASTM D 4640-86. The 121 gel time test was conducted according to ASTM 3056-96. Specific gravity was run at 25° C. Water tolerance testing was conducted by weighing a resin sample into a vessel at 25° C. and placing the vessel over a piece of newsprint.
Deionized or distilled water was added to the sample with stirring and the newsprint viewed by looking from the top of the vessel through the sample solution. The endpoint was reached when the newsprint could no longer be read through the solution and is expressed as weight percent water added to the sample. The pH of a solution was measured at 25° C. on neat samples using an ACCUMET® Model 15 pH meter from Fisher Scientific. Solids were measured using a standard forced air oven technique. A known weight of a resin was placed in an oven to allow the volatiles to evaporate. After cooling, the sample is reweighed. The percent solids were calculated by dividing the final weight by the original weight, multiplied by 100. Free formaldehyde was measured according to the following procedure. Six g of sample was weighed into a flask. 45 ml of methanol was added with stirring to dissolve the sample. Bromophenol blue indicator was added to he vessel. A blank was prepared in the same manner without the sample.
Sample and blank were titrated to a blue green endpoint. If prior to titration the sample solution was blue it was titrated with sulfuric acid. If the solution was yellow it was titrated with NaOH. Subsequently, 15 ml of a 10% aqueous hydroxylamine hydrochloride solution was added to the vessel and allowed to stand for from 5 to 10 minutes. The sample and blank were then titrated with NaOH to a blue green end point.
The percent free formaldehyde was calculated by subtracting the ml of NaOH required to reach the blue green end point of the blank from the ml of NaOH required to reach the blue green endpoint of the blank from the ml of NaOH required to reach the endpoint of the sample solution, multiplying that number by the normality of the NaOH and then by 3.003 and finally dividing the result by the weight of the sample.
EXAMPLE 1
100 g of phenol, 127.16 g of a 50% aqueous solution of formaldehyde and 14.8 g of a 20% aqueous solution of NaOH were added to a vessel with stirring and heated to 70° C. and held at that temperature for 20 minutes. The reaction mixture was then allowed to reflux for an additional 14 minutes. The reaction mixture was cooled back to 80° C. and held until a water tolerance of from 280 to 320% was obtained. The mixture was then cool rapidly to 70° C. and 8.0 g of a 20% aqueous solution of NaOH was added. The mixture was then cooled to room temperature and 8.86 g of methanol was added and mixed for 10 to 15 minutes.
EXAMPLE 2
400g of phenol and 60 g of a 10% aqueous NaOH solution were added to a vessel with stirring and heated to 60° C. 8 g of casein was added to the vessel and stirred until the casein dissolved. The reaction mixture was cooled to 50° C. and 516 g of a 50% aqueous solution of formaldehyde and 20 g of methanol were added. The reaction mixture was heated to 70° C. and held at temperature for 20 minutes. 20 g of melamine was added and the reaction mixture was allowed to reflux for 20 to 30 minutes until a hot plate cure of about 40 seconds was obtained. The reaction mixture was then cooled to 65° C. and 20 g leucine was added and allowed to dissolve. After dissolving the leucine, 5 g of sodium sulfite was added and stirred until it dissolved in the reaction mixture. The reaction mixture was then allowed to cool to room temperature.
EXAMPLE 3
400 g of phenol and 60 g of a 20% aqueous solution of NaOH were added to a vessel with stirring and heated to 60° C. 20 g of casein was added and stirred until dissolved in the reaction mixture. The mixture was then cooled to 50° C. and 516 g of a 50% aqueous solution of formaldehyde and 35 g of methanol were added to the reaction mixture. The mixture was heated to 70° C. and held at that temperature for 20 minutes. 20 g of melamine was then added and the mixture was allowed to reflux until a hot plate cure of about 45 seconds was obtained. The mixture was cooled to 65° C. and an additional 20 g was added to the reaction mixture and allowed to mix for 5 minutes. 20 g of glycine was then added and allowed to dissolve in the mixture. After dissolving the glycine, 5 g of sodium sulfite was added to the mixture with stirring until dissolved. The reaction mixture was then allowed to cool to room temperature and adjusted to a solids level of about 55% with deionized water.
EXAMPLE 4
The same procedure used in Example 3 was followed in Example 4 with the exception that no melamine was added to the reaction mixture.
Ingredients
Amount
Phenol
400
Formaldehyde (50%)
516
Casein
20
Methanol
40
NaOH (20%)
60
NaOH (20%)
30
Na 2 SO 3
5
Glycine
15
DI Water
55
EXAMPLE 5
100 g of phenol, 58 g of a 91% aqueous solution of paraformaldehyde, 12 g of isopropyl alcohol and 6 g of methanol were added to a reaction vessel with stirring. Subsequently 3 g of a 20% aqueous solution of NaOH and 1 g of triethylamine (TEA) were added slowly with stirring. The reaction mixture was heated to 75° C. and held at temperature for 30 minutes. The mixture was refluxed until a hot plate cure of about 38 seconds was obtained and then cooled to 60° C. 25 g of methanol was added during the cool down to 60° C. and the reaction mixture was held with stirring for 10 minutes. The reaction mixture was then cooled to 50° C. and 3.8 g of an 88% aqueous solution of lactic acid was added. The reaction mixture was allowed to cool to room temperature and adjusted to a percent non-volatiles of about 65% with methanol.
EXAMPLE 6
The same procedure used in Example 5 was followed in Example 6 with the exception that melamine was added prior to reflux and an additional 2 g of glycine predissolved in a 20% aqueous NaOH solution was added after reflux.
Ingredients
Amount
Phenol
100.00
Paraformaldehyde (91%)
58.00
Isopropyl alcohol
12.00
Methanol
6.00
NaOH (20%)
3.00
Triethylamine
1.00
Melamine
4.00
Methanol
25.00
Glycine
1.34
NaOH (20%)
5.00
Lactic Acid (88%)
2.00
Glycine
2.00
EXAMPLE 7
The same procedure used in Example 6 was followed in Example 7 with the exception that glycine was dissolved in water prior to addition to the reaction mixture.
Ingredients
Amount
Phenol
100.00
Paraformaldehyde (91%)
58.00
Ethanol
9.00
Methanol
9.00
NaOH (20%)
3.00
Triethylamine
1.00
Melamine
4.00
Urea
2.00
Glycine
2.00
DI Water
8.00
Lactic Acid (88%)
2.00
EXAMPLE 8
95 g of formaldehyde was added to a vessel and heated to 50° C. The pH was adjusted to 7.5 with a 20% aqueous NaOH solution. 45 g of urea was added to the vessel and the temperature raised to 95° C. The reaction mixture was allowed to reflux. The pH was maintained during reflux by adding small amounts of 20% aqueous NaOH. After refluxing the reaction mixture was cooled to 75° C. and the pH was adjusted to 5.4-5.6 with a 10% aqueous formic acid solution. The mixture was then reheated to 95° C. and held at that temperature for 1 hour. The mixture was then cooled to 60° C. and the pH adjusted to 9.2. Half of the mixture was decanted. 2% by weight of glycine based on the weight of the mixture remaining in the vessel, dissolved in 40 g of warm water was added to the mixture in the vessel with stirring at a temperature of 60° C. for 30 minutes and then cooled to room temperature.
The amount of free formaldehyde in the glycine treated resin and in the untreated resin was determined. The results are in Table I.
TABLE I
Example 10
1
2
3
4
5
6
7
8
Visc (cps)
198
440
328
162
1625
280
Hot plate cure (sec)
34
37
38
37
31
43
121 gel time (min)
14.1
13.5
155
15.3
11.1
10.7
13.8
Sp. Gravity
1.187
1.195
1.192
Initial Water Tolerance
450
93
115
200
(%)
pH
9.4
8.2
8.1
8.9
5.05
7.79
6.48
9.2
Solids
55.0
58.8
57.2
54.4
64.0
64.0
64.0
Free formaldehyde
1.0
0.1
0.1
1.0
0.2
0.3
2.1*
before cure (%)
*The free formaldehyde in the resin prior to addition of the glycine was 4.4% by weight.
EXAMPLES 9-12
Examples 9-12 were prepared as above and subject to a one week stability study by placing samples of each in a constant temperature oven at 40° C. The object was to illustrate the increased water stability of aqueous resins containing an amino acid compared to the same composition without the amino acid. Examples 9 and 10 were prepared according to Example 3, with the exception that glycine was not added to Example 10.
Examples 11 and 12 were prepared in the same manner as Example 1 with the exception that in Example 12 g glycine was added after the first addition of NaOH and allowed to react for 30 to 40 minutes.
The results of the heat aging on viscosity and water tolerance are found in Table II.
TABLE II
Example 9
Example 10
Example 11
Example 12
Visc
Water
Visc
Water
Visc
Water
Visc
Water
Day
(cps)
Tol (%)
(cps)
Tol (%)
(cps)
Tol (%)
(cps)
Tol (%)
Initial
350
187
36
110
225
440
280
460
Wat Tol.
1
570
175
225
94
265
405
465
600
4
2750
210
745
52
875
380
2950
1144
5
3400
220
1060
30
1520
360
6800
1950
6
7700
350
2250
<8
2780
360
23500
>2000
7
14400
1296
6250
390
59500
72000
|
The present invention relates to aldehyde resins having low amounts of free aldehydes and methods of preparing the resins. The reduction in the amount of free aldehydes is accomplished by adding an amino acid to the resin formulation prior to form the resin.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional of U.S. patent application Ser. No. 11/121,026, entitled “HYPERBRANCHED POLYMER AND CYCLOALIPHATIC EPOXY RESIN THERMOSETS,” filed on May 3, 2005, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to rigid and clear thermosetting compositions formed from dendritic or hyperbranched polymers and cylcoaliphatic epoxy resins. The compositions may be used for coatings such as electronic device packaging, adhesives, wire coatings, and finishes.
BACKGROUND OF THE INVENTION
[0003] Known commercial thermoset resins from dendritic polymers such as acrylate and urethane thermosets have excellent processing and reactivity characteristics when compared to their linear polymer analogs due to their globular structure and high density of reactive functionalities. However, such thermoset materials may not be suitable for a wide range of electrical and electronic applications due to low thermal stability and moderate electrical properties. On the other hand, epoxy functionalized dendrimers have received little commercial success due to rheological issues associated with their extreme viscosities.
[0004] Dendritic polymers are a relatively new class of macromolecules with a hyperbranched structure formed from the incorporation of repetitive branching sequences by a multiplicative growth process beginning with a small molecule. As such, dendrimers typically consist of a core, from which branches extend in three-dimensions, forming a globular structure with a large number of end groups at the peripheral surface. Consequently, dendrimers differ significantly from conventional linear polymers in their physical properties. Their compact globular structure coupled with the absence of restrictive interchain entanglements results in low viscosities that are substantially lower than their linear polymer analogues of similar molecular weights as disclosed in “Properties and Applications of Dendritic Polymers”, B. Pettersson, Pyramid Communication AB, Sweden, 2001, and by R. Mezzenga, L. Boogh, and J. E. Manson, Composite Science and Technology, 61, 787, 2001, the disclosure of each expressly incorporated by reference herein. Furthermore, the variability in the chemical compositions of the core molecule, the chain extender, and the high density terminal groups allow for solubilities in a large variety of solvents.
[0005] To date, only a few dendritic polymers have been successfully commercialized. Among the commercial hyperbranched polymers are those that are based on polyalcohol and an aliphatic tertiary polyester backbone such as the structure shown in FIG. 1 . They are sold under the trade name Boltorn™ by the Perstrop Specialty Chemicals (Boltorn is a trademark of Perstrop Specialty Chemicals). Most of the commercial applications of this family of dendritic polymers rely on the exceptionally high concentration of reactive hydroxyl groups that provide for a rapid curing in thermosetting applications. The most prominent applications are in the coating and in the polyurethane industries as discussed by D. James in the article “Parquet Coating II,” at the European Coating Conference, Nov. 14, 2002, the disclosure of which is expressly incorporated by reference herein. Currently, different Boltorn™ product grades are used by the radiation curable coating, the powder coating, the decorative coating, and the polyurethane industries in both automotive and non-automotive applications as discussed by D. James in PRA Radcure Coatings and Inks, Jun. 24, 2002, the disclosure of which is expressly incorporated by reference herein.
[0006] Although the application of dendritic polymers in epoxy resin compositions has been reported by L. Boogh, B. Pettersson, and J. E. Manson in Polymer, 40, 2249, 1999, the disclosure of which is expressly incorporated by reference herein, their utility in these instances is limited to their phase separation-induced toughening effect in the Bisphenol-A family type of epoxy resins that are cured by non-cationic initiation. Functionalization of the dendritic polymer with epoxy groups has also been reported and some commercial grades are available.
SUMMARY OF THE INVENTION
[0007] One embodiment of the present invention includes a coating comprising a dendritic polyol, a cycloaliphatic epoxy resin, and a cationic initiator. The coating may include a cycloaliphatic epoxy resin selected from the group consisting essentially of 3,4-epoxycyclohexyl methyl-3,4-epoxy-cyclohexane carboxylate, bis(3,4-epoxycyclohexyl) adipate, and 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, a dendritic polyol selected from the group consisting essentially of Boltorn H20, Boltorn H30, Boltorn H40, Boltorn H2003, and Boltorn H2004, and/or an initiator selected from the group consisting essentially of FC520, Cp66, Nacure XC 7231, and Nacure super A218.
[0008] Another embodiment of the present invention includes a process of coating metal with an electrical insulator, the process including the steps of providing a mixture of a dendritic polyol, a cycloaliphatic epoxy resin, and a cationic initiator, coating the metal with the mixture, and heating the mixture. The electrical insulator may include a cycloaliphatic epoxy resin selected from the group consisting essentially of 3,4-epoxycyclohexyl methyl-3,4-epoxy-cyclohexane carbonate, bis(3,4-epoxycyclohexyl) adipate, and 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, a dendritic polyol selected from the group consisting essentially of Boltorn H20, Boltorn H30, Boltorn H40, Boltorn H2003, and Boltorn H2004, and/or an initiator selected from the group consisting essentially of FC520, Cp66, Nacure XC 7231, and Nacure super A218.
[0009] Another embodiment of the present invention includes a composition of matter comprising a dendritic polyol, a cycloaliphatic epoxy resin, and a cationic initiator. The composition of matter may include a dendritic polyol comprising about 5-30% by weight of the composition. The composition of matter may also include a dendritic polyol comprising about 10-20% by weight of the composition. The composition of matter may also include a cationic initiator comprising about 0.1-3.0% by weight of the composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
[0011] FIG. 1 is a structural diagram a hyperbranched or dendritic polyol such as Boltorn™.
[0012] Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate embodiments of the invention in several forms and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The embodiments discussed below are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
[0014] The present invention includes the a series of thermoset compositions formed from the combination of cycloaliphatic epoxy resins and dendritic polyols and the method or making such compositions. The resulting thermoset compositions have the superior processing and high reactivity characteristics of the multifunctional globular structure of the dendritic polyols and the excellent thermal degradation resistance and electrical properties known for cycloaliphatic/polyol based compositions. As discussed below, the combination of hyperbranched or dendritic polyols with a variety of cycloaliphatic epoxy resins shows excellent reactivities at temperatures as low as 80° C. and high thermal degradation temperatures, greater than 400° C., when catalyzed by certain initiators. Also, cycloaliphatic/polyol based compositions are known to have good outdoor weathering, superior arc-track resistance, good dielectric properties, and low ionic contents. The thermoset compositions of the present invention are moderately tough, clear systems and can be used in the encapsulation of electronics where transparency or “see-through” is important.
[0015] The thermoset compositions of the present invention are made by dissolving polyalcohol based dendrimers, such as the Boltorn™ family, in cycloaliphatic epoxy resins by heating at a temperature in the range of 80° C.-120° C. The resulting mixture remains after cooling to room temperature. Next, a specific amount of a cationic initiator is added at a specified temperature to cure the mixture. Examples of the this method are described below. The resulting thermoset compositions have excellent rigid and transparent characteristics. Another feature of the present invention is the pot life of the mixture including a polyalcohol based dendrimer, a cycloaliphatic epoxy resin, and a cationic initiator. This one-package mixture may be stored at room temperature for several months. The mixture may then be used, for example as a coating. Heat is applied to the mixture to activate the cationic initiator may cure the mixture leaving the thermoset coating.
EXAMPLES
[0016] The structure and properties of the dendritic polyols, the cycloaliphatic epoxy resins, and the cationic initiators used in the formulations of the following examples of the present invention are given in Tables I, II, and III. Table I illustrates the structure of the cycloaliphatic epoxy resins used in these examples. In the examples described below, three different cycloaliphatic epoxy resins, 3,4-epoxycyclohexyl methyl-3,4-epoxy-cyclohexane carboxylate, bis(3,4-epoxycyclohexyl) adipate, and 2-(3,4-epoxycyclohexyl-5,5-Spiro-3,4-epoxy) cyclohexane-meta-dioxane, all produced by Dow Chemical, are used. Table II lists the cationic initiators used in these examples along with their approximate structures and their respective manufacturers. The cationic initiators used in the examples described below include FC520, Cp66, Nacure XC 7231, and Nacure super A218. Table III lists characteristics of several different generations of dendrimers of Boltorn™ polyols used in these examples. The dendrimers include Boltorn™ H20, H30, H40, H2003, and H2004.
[0000]
TABLE I
Structure of Cycloaliphatic Epoxy Resins (Dow Chemical Co.) used in the
Formulations
EEW
Code
Name
Structure
*
ERL4221
3,4-epoxycyclohexyl methyl-3,4-epoxy-cyclohexane carboxylate
136
ERL4299
Bis(3,4-epoxycyclohexyl) adipate
200
ERL4234
2-(3,4-epoxycyclohexyl-5,5-Spiro-3,4-epoxy) cyclohexane-meta-dioxane
144
*EEW: Epoxy Equivalent Weight
[0000]
TABLE II
Cationic Initiators and Approximate Structures
Cationic Initiator
Structure
Manufacturer
FC520
Diethyl ammonium triflate
3M
Cp66
S-butenethiophene
Asahi Denka
hexafluoroantimonate
Nacure XC 7231
Ammonium hexafluoroantimonate
King Industries
Nacure super A218
Lewis acid (zinc salt)
King Industries
[0000]
TABLE III
Characteristics of Different Generation Dendrimers of Boltorn ™ Polyols
Product
H20
H30
H40
H2003
H2004
Hydroxyl number
505
495
485
298
125
Mw (g/mole)
1750
3570
7250
2500
3200
Functionality
16
32
64
12
6
Viscosity at 110° C.
7
40
110
1
20
(×10 −3 )
[0017] In the following examples, the formulations of the dendrimer/epoxy mixture were prepared by dissolving an appropriate amount of the dendritic polyol in the cycloaliphatic epoxy resin at about 100° C. The dendritic polymers remained in solution for months after cooling to room temperature. The amount of dissolved dendrimers in the epoxy resin is limited by solubility and by viscosity requirements. Concentrations are in the range of 5-30% by weight of the dendrimer polyol and further concentrations are in the range of 10-20% by weight. As discussed below, non-dendritic polyols may be added to the mixture to reduce the viscosity or to impart desirable characteristics of the non-dendritic polyols to the cured thermoset.
[0018] Curing of the dendrimer/epoxy solutions was achieved by the addition of one of the cationic initiators listed in Table II. After one of the initiators is added to the dendrimer/epoxy solution, the formulation was heated to a required temperature for an appropriate time period. The preferred amount of cationic initiator is between 0.1-3.0% by weight of the total composition. The optimum amount varies with the type of initiator. Some initiators, such as FC520 and Nacure XC7231, cause coloration of the cured formulations when used at relatively high concentrations (3% by weight). Excessive cure exotherms and lower degradation temperatures of the cured products are other concerns for formulations involving high initiator concentrations.
[0019] Table IV (shown below) illustrates the influence of the concentration of the cationic initiator, Nacure A218 in this example, on the cure temperature (T max ° C.) for three different mixtures of dendrimer/epoxy solution. The cure temperature of each formulation depends on the specific initiator and its concentration. For the examples shown in Table IV, each of the three formulations includes about 15% dendrimer and about 85% cycloaliphatic epoxy resin. The three formulations tested are mixtures of Boltorn H20 and ERL4234, Boltorn H40 and ERL4234, and Boltorn H20 and ERL4221, respectively. The cationic initiator used was Nacure A218. For each of the three formulations of dendrimer and cycloaliphatic epoxy resin, three different concentrations of Nacure A218 were added. The cure temperature was determined from the peak maxima of differential scanning calorimetry (DSC) measurements. The three concentrations of Nacure A218 used for the Boltorn H20/ERL4234 and Boltorn H40/ERL4234 formulations were 0.25, 0.5, and 1.0 percent by weight of the mixture. Concentrations of 0.5, 1.0, and 3.0 percent by weight of the mixture were added to the Boltorn H20/ERL4221 formulations. As shown in Table IV, the formulations having the lower concentrations of initiator required a higher cure temperature.
[0000]
TABLE IV
The Influence of Initiator (Nacure A218) Concentration on T max
Concentration
of Initiator
Dendrimer/Epoxy (15/85% w/w)
(% wt)
T max , ° C.
Boltorn H20/ERL4234
0.25
148
Boltorn H20/ERL4234
0.5
142
Boltorn H20/ERL4234
1.0
133
Boltorn H40/ERL4234
0.25
154
Boltorn H40/ERL4234
0.5
147
Boltorn H40/ERL4234
1.0
133
Boltorn H20/ERL4221
0.5
161
Boltorn H20/ERL4221
1.0
148
Boltorn H20/ERL4221
3.0
114
[0020] Table V (shown below) illustrates the cure temperatures (T max ° C.) of a formulation including Boltorn H20 and ERL4221 in a 15:85% weight to weight ratio using four different initiators. The cure temperatures were determined for each of the four initiators for formulations having a concentration of initiator of about 1% and about 3% by weight of the mixture. Tables IV and V illustrate a set of optimum cure temperatures as a function of the initiator and its concentration for representative formulations. The broad range of curing temperatures (T max ) obtained from the different initiators allows for thermoset applications having different process temperature requirements. As should be obvious from the foregoing, a variety of cationic initiators could be used in a variety of concentrations to yield the desired cure temperature and thermoset characteristics.
[0000]
TABLE V
Cure Temperatures (T max ) of Boltorn H20/ERL4221 (15:85% w/w)
Formulations Using Different Initiators
Initiator
T max (° C.) at 1% wt**
T max (° C.) at 3% wt**
XC7231
117
98
A218
148
114
FC520
180
149
Cp6
126
—
*Cure temperature at maximum of exothermic peak (from DSC)
**Concentration of initiator
[0021] Table VI (shown below) compares the cure temperature (T max ° C.) for formulations having different epoxy resin and cationic initiators. The initiators, Nacure A218 and Nacure XC7213, are about 1% by weight of the dendrimer/epoxy solution. Table VII compares formulations having different dendritic polyols and a single epoxy resin. In all of the examples listed in Table VII, the cycloaliphatic epoxy resin was ERL4221. The ERL4221 was combined with the dendritic polymers Boltorn H20, H40, H2003, and H2004 to four different dendrimer/epoxy solutions. Each of the dendrimer/epoxy solutions were divided into three groups. Nacure XC7231 at a concentration of about 3% by weight of the solution was added to each of the solutions in the first group. Nacure XC7231 at a concentration of about 1% by weight of the solution was added to each of the solutions in the second group. FC520 at a concentration of about 1% by weight of the solution was added to each of the solutions in the third group. The measurements of Tables VI and VII indicate that the reaction or cure temperature (T max ) depends on the type of epoxy resin but is independent of the dendrimer generation.
[0000]
TABLE VI
Dependence of T max on the Type of Cycloaliphatic Epoxy Resinn
for Boltor H20/Epoxy (15:85% w/w) Formulations
Initiator at 1%
concentration
Epoxy resin
T max (° C.)
Nacure A218
ERL4299
123
Nacure A218
ERL4221
148
Nacure A218
ERL4234
133
Nacure XC7213
ERL4299
110
Nacure XC7213
ERL4221
117
Nacure XC7213
ERL4234
110
[0000]
TABLE VII
T max as a Function of Boltorn Dendrimer Generation in Formulations with
ERL4221
Dendritic
Concentration of
Polymer
Initiator
Initiator (wt %)
T max (° C.)
Boltorn H20
Nacure XC7231
3
101
Boltorn H40
Nacure XC7231
3
108
Boltorn H2003
Nacure XC7231
3
98
Boltorn H2004
Nacure XC7231
3
102
Boltorn H20
Nacure XC7231
1
117
Boltorn H40
Nacure XC7231
1
121
Boltorn H2003
Nacure XC7231
1
113
Boltorn H2004
Nacure XC7231
1
117
Boltorn H20
FC520
1
180
Boltorn H40
FC520
1
178
Boltorn H2003
FC520
1
184
Boltorn H2004
FC520
1
186
[0022] Non-dendritic polyols may also be incorporated in the formulations to achieve certain desirable properties for the cured thermoset. For example, flexible polyols may be added to improve the impact resistance or to provide for a flexible thermoset products. The addition of non-dendritic polyols at the ratio of 1:2 (non-dendritic:dendritic polyols by weight) did not significantly change the cure temperature of the compositions. Representative examples are given in Table VIII.
[0000]
TABLE VIII
Comparison of Cure Temperatures in Formulations
with and without Linear Polyols
Dendrimer/Epoxy
(15%/85% by
T c 1
T c1 1
Initiator at
Non-dendritic
weight)
(° C.)
(° C.)
1% by weight
Polyol
Boltorn H20/
110
117
XC7231
BPAE 2
ERL4299
Boltorn H20/ER4221
148
154
A218
BPAE
Boltorn H20/
117
124
XC7231
BPAE
ERL4299
Boltorn H20/ER4221
117
121
XC7231
PTHF 3
1 T c and T c1 are the cure temperatures for formulations containing dendrimer only and linear polyol, respectively.
2 BPAE is Bisphenol-A ethoxylate (4 ethoxylate/phenol, Mn = 580); at 2:1 Boltorn/BPAE by weight.
3 Polytetrahydrofuran (Mn = 250); at 2:1 Boltorn/PTHF by weight.
[0023] As shown in Table VIII, the addition of BPAE and PTHF to several dendrimer/epoxy solutions did not significantly effect the cure temperature of the solutions when the cationic initiator was added. In addition to BPAE and PTHF, other suitable non-dendritic polyols or mixtures of non-dendritic polyols could be added to a dendrimer/epoxy/cationic initiator solution to produce a thermoset having a variety of desired characteristics.
[0000]
TABLE IX
Decomposition Temperature in Air Atmosphere for Representative
Formulations
Initiator
Concentration
Dendrimer/Epoxy (15/85% w/w)
Initiator
(wt %)
T d 1 (° C.)
Boltorn H20/ERL4299
XC7231
1
420
Boltorn H20/ERL4299
XC7231
3
414
Boltorn H20/ERL4299
XC7231
0.5
424
Boltorn H40/ERL4221
XC7231
1
390
Boltorn H20/ERL4299
Cp66
0.5
418
Boltorn H20/ERL4299
FC520
0.5
358
Boltorn H20/ERL4221
FC520
0.5
335
Boltorn H40/ERL4221
FC520
0.5
323
Boltorn H2004/ERL4221
FC520
0.5
326
Boltorn H20/ERL4221
A-218
1
311
Boltorn H20/ERL4299
A-218
0.5
317
Boltorn H40/ERL4234
A-218
0.25
315
1 T d is the decomposition temperature in air as measured at 5% weight loss by thermogravimetric analysis.
[0024] The investigated dendritic polyol/cycloaliphatic epoxy compositions show good thermal stability in air. The decomposition temperatures as measured by thermogravimeteric analysis for some of the examples of the dendrimer/epoxy/initiator mixtures are given in Table IX. Compositions cured with Nacure XC7231 or with Cp66 showed the highest decomposition temperatures, greater than 400° C., in an air atmosphere. The concentration of any of the initiators tested to achieve the highest decomposition temperatures is in the range of 0.25-1% by weight of total composition and a further concentration is in the range of 0.5-0.75% by weight.
[0025] While this invention has been described as having an exemplary design, the present invention may 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.
|
The present invention relates to rigid and clear thermosetting compositions formed from dendritic or hyperbranched polymers and cylcoaliphatic epoxy resins. The compositions may be used for coatings such as electronic device packaging, adhesives, wire coatings, and finishes.
| 2
|
[0001] This application claims the benefit of U.S. Provisional Applicant Ser. No. 61/439,564, filed on Feb. 4, 2011, the entire contents of which are incorporated herein by reference.
FIELD
[0002] This disclosure relates to heat exchangers in general, and, more particularly, to heat exchangers, including but not limited to shell-and-tube heat exchangers, employing heat conducting foam material.
BACKGROUND
[0003] Heat exchangers are used in many different types of systems for transferring heat between fluids in single phase, binary or two-phase applications. An example of a commonly used heat exchanger is a shell-and-tube heat exchanger. Generally, a shell-and-tube heat exchanger includes multiple tubes placed between two tube sheets and encapsulated in a shell. A first fluid is passed through the tubes and a second fluid is passed through the shell such that it flows past the tubes separated from the first fluid. Heat energy is transferred between the first fluid and second fluid through the walls of the tubes.
[0004] A shell-and-tube heat exchanger is considered the primary heat exchanger in industrial heat transfer applications since they are economical to build and operate. However, shell-and-tube heat exchangers are not generally known for having high heat transfer efficiency.
SUMMARY
[0005] Shell-and-tube heat exchangers are described that utilize one or more foam heat transfer units engaged with the tubes to enhance the heat transfer between first and second fluids. The foam of the heat transfer units can be any thermally conductive foam material that enhances heat transfer, for example graphite foam. The shell-and-tube heat exchangers described herein are highly efficient, inexpensive to build, and corrosion resistant. The described heat exchangers can be used in a variety of applications, including but not limited to, low thermal driving force applications, power generation applications, and non-power generation applications such as refrigeration and cryogenics. The foam heat transfer units can be made from any thermally conductive foam material including, but not limited to, graphite foam or metal foam.
[0006] In one embodiment, a heat exchanger includes a tube having a central axis and an outer surface. A heat transfer unit is connected to and in thermal contact with the outer surface of the tube, with the heat transfer unit having a heat transfer surface extending substantially radially from the outer surface of the tube. The heat transfer unit includes graphite foam. For example, the heat transfer can consist essentially of, or consist of, graphite foam.
[0007] In another embodiment, a heat exchanger includes a tube bundle having a central axis and a plurality of tubes for conveying a first fluid. A first tube sheet and a second tube sheet are provided, and each of the tubes includes a first end joined to the first tube sheet in a manner to prevent fluid leakage between the first end and the first tube sheet and a second end joined to the second tube sheet in a manner to prevent fluid leakage between the second end and the second tube sheet. A heat transfer unit is connected to and in thermal contact with the tubes, with the heat transfer unit consisting essentially of graphite foam.
[0008] One suitable method for connecting the tubes and the tube sheets is friction-stir-welding (FSW). The use of FSW is particularly beneficial in heat exchanger applications subject to corrosive service, since the FSW process eliminates seams, no dissimilar metals are used and, in the case of saltwater environments, no galvanic cell is created.
[0009] In another embodiment, the heat transfer unit is in the form of a generally radiused and wedge-shaped, planar body that consists essentially of foam material, for example graphite foam.
[0010] The body includes first and second opposite major surfaces, a support rod hole or cut-out extending through the body from the first major surface to the second major surface, an arcuate radially outer edge connected to linear side edges at opposite ends of the outer edge, and at least two tube contact surfaces opposite the radially outer edge. In other embodiments, the heat transfer units can be a combination of radiused and triangular or square shaped to fit in the pitch space between tubes. All of the heat transfer units described herein can be used by themselves or together in various combinations that one finds suitable to increase the heat transfer efficiency of the heat exchanger.
[0011] In an embodiment, the tubes can be twisted around a foam heat transfer unit. In addition, each tube can be twisted around its own axis to further increase heat transfer efficiency.
[0012] The tubes of the shell-and-tube heat exchangers described herein can be arranged in numerous patterns and pitches, including but not limited to, an equilateral triangular pattern defining a triangular pitch between tubes, a square pattern defining a square pitch between tubes, and a staggered square pattern defining a square or diamond pitch between tubes.
[0013] The shell-and-tube heat exchangers described herein can also be configured to have any desired flow configuration, including but not limited to, cross-flow, counter-current flow, and co-current flow. In addition, the tubes can have any desired tube layout/configuration including, but not limited to, single pass and multi-pass. Further, the shell, tubes, tube sheets, and other components of the described heat exchangers can be made of any materials suitable for the desired application of the heat exchanger including, but not limited to, metals such as aluminum, titanium, copper and bronze, steels such as carbon steel and high alloy stainless steels, and non-metals such as plastics, fiber-reinforced plastics, thermally enhanced polymers, and thermoplastics.
DRAWINGS
[0014] FIG. 1 shows a conventional shell-and-tube heat exchanger.
[0015] FIG. 2 is an exploded view of an improved shell-and-tube heat exchanger described herein.
[0016] FIG. 3 illustrates a tube bundle for the shell-and-tube heat exchanger of FIG. 2 .
[0017] FIG. 4 is a partial view of the tube bundle of FIG. 3 .
[0018] FIG. 5 illustrates a foam heat transfer unit used with the tube bundle of FIGS. 2-4 .
[0019] FIGS. 6A-E illustrate an exemplary process of forming the heat transfer unit of FIG. 5 .
[0020] FIG. 7 illustrates another example of a foam heat transfer unit useable with the tube bundle.
[0021] FIG. 8 illustrates still another example of a foam heat transfer unit.
[0022] FIG. 9 illustrates still another example of a foam heat transfer unit.
[0023] FIG. 10A is a cross-sectional view of a tube bundle with another example of a foam heat transfer unit.
[0024] FIGS. 10B and 10C illustrate additional examples of tube patterns for tube bundles.
[0025] FIG. 11 illustrates an example of an improved shell-and-tube heat exchanger that employs twisted tubes together with a foam heat transfer unit.
[0026] FIG. 12 is a cross-sectional view of the shell-and-tube heat exchanger of FIG. 11 .
[0027] FIG. 13 is a cross-sectional view of another implementation of twisted tubes and foam heat transfer units.
[0028] FIG. 14 illustrates details of the portion within the triangle in FIG. 13 .
[0029] FIG. 15 illustrates details of the portion within the hexagon in FIG. 13 .
[0030] FIG. 16 is a cross-sectional view of an improved shell-and-tube heat exchanger that employs an additional example of foam heat transfer units.
[0031] FIGS. 17A-F illustrate examples of patterns formed by different configurations of foam heat transfer units.
[0032] FIG. 18 shows an example of a plate that can be used to strengthen a heat transfer unit.
DETAILED DESCRIPTION
[0033] FIG. 1 shows a conventional shell-and-tube heat exchanger 10 that is configured to exchange heat between a first fluid and a second fluid in a single-pass, primarily counter-flow (the two fluids flow primarily in opposite directions) arrangement. The heat exchanger 10 has tubes 12 , a tube sheet 14 at each end of the tubes, baffles 16 , an input plenum 18 for a first fluid, an output plenum 20 for the first fluid, a shell 22 , an inlet 24 to the input plenum for the first fluid, and an outlet 26 from the output plenum for the first fluid. In addition, the shell 22 includes an inlet 28 for a second fluid and an outlet 30 for the second fluid.
[0034] The first fluid and the second fluid are at different temperatures. For example, the first fluid can be at a lower temperature than the second fluid so that the second fluid is cooled by the first fluid.
[0035] During operation, the first fluid enters through the inlet 24 and is distributed by the manifold or plenum 18 to the tubes 12 whose ends are in communication with the plenum 18 . The first fluid flows through the tubes 12 to the second end of the tubes and into the output plenum 20 and then through the outlet 26 . At the same time, the second fluid is introduced into the shell 22 through the inlet 28 . The second fluid flows around and past the tubes 12 in contact with the outer surfaces thereof, exchanging heat with the first fluid flowing through the tubes 12 . The baffles 16 help increase the flow path length of the second fluid, thereby increasing the interaction and residence time between the second fluid in the shell-side and the walls of tubes. The second fluid ultimately exits through the outlet 30 .
[0036] Turning to FIGS. 2-4 , an improved shell-and-tube heat exchanger 50 is illustrated. The heat exchanger is illustrated as a single-pass, primarily counter-flow (the two fluids flow primarily in opposite directions) arrangement. However, it is to be realized that the heat exchanger 50 could also be configured as a multi-pass system, as well as for cross-flow (the two fluids flow primarily generally perpendicular to one another), co-current flow (the fluids primarily flow in the same directions), or the two fluids flow can flow at any angle therebetween.
[0037] The heat exchanger 50 includes a shell 52 and a tube bundle 54 that is configured to be disposable in the shell 52 . In the illustrated embodiment, the shell 52 includes an axial inlet 56 at a first end for introducing a first fluid and an axial outlet 58 at the opposite second end for the first fluid. In addition, the shell includes a radial inlet 60 near the first end for introducing a second fluid and a radial outlet 62 near the second end for the second fluid.
[0038] The shell 52 is configured to enclose the tube bundle 54 and constrain the second fluid to flow along the surfaces of tubes in the tube bundle. The shell 52 can be made of any material that is suitably resistant to corrosion or other effects from contact with the type of second fluid being used, as well as be suitable for the environment in which the heat exchanger 50 is used. For example, the shell can be made of a metal including, but not limited to, steel or aluminum, or from a non-metal material including, but not limited to, a plastic or fiber-reinforced plastic.
[0039] The tube bundle 54 extends substantially the length of the shell and includes a plurality of hollow tubes 64 for conveying the first fluid through the heat exchanger 50 . The tubes 64 are fixed at a first end 66 to a first tube sheet 68 and fixed at a second end 70 to a second tube sheet 72 . As would be understood by a person of ordinary skill in the art, the tube sheets 68 , 72 are sized to fit within the ends of the shell 52 with a relatively close fit between the outer surfaces of the tube sheets and the inner surface of the shell. When the tube bundle 54 is installed inside the shell 52 , the tube sheets of the tube bundle and the shell collectively define an interior chamber that contains the tubes 64 of the tube bundle. The radial inlet 60 and radial outlet 62 for the second fluid are in fluid communication with the interior chamber. Due to the closeness of the fit and/or through additional sealing, leakage of the second fluid from the interior chamber of the shell past the interface between the outer surfaces of the tube sheets 68 , 72 and the inner surface of the shell is prevented.
[0040] As shown in FIG. 3 , the ends of the tubes 64 penetrate through the tube sheets 68 , 72 via holes in the tube sheets so that inlets/outlets of the tubes are provided on the sides of the tube sheets facing away from the interior chamber of the shell. The ends of the tubes 64 may be attached to the tube sheets in any manner to prevent fluid leakage between the tubes 64 and the holes through the tube sheets. In one example, the ends of the tubes are attached to the tube sheets by FSW. The use of FSW is particularly beneficial where the heat exchanger is used in an environment where it is subject to corrosion, since the FSW process eliminates seams, no dissimilar metals are used and, in the case of saltwater environments, no galvanic cell is created.
[0041] FSW is a known method for joining elements of the same material. Immense friction is provided to the elements such that the immediate vicinity of the joining area is heated to temperatures below the melting point. This softens the adjoining sections, but because the material remains in a solid state, the original material properties are retained. Movement or stirring along the weld line forces the softened material from the elements towards the trailing edge, causing the adjacent regions to fuse, thereby forming a weld. FSW reduces or eliminates galvanic corrosion due to contact between dissimilar metals at end joints. Furthermore, the resultant weld retains the material properties of the material of the joined sections. Further information on FSW is disclosed in U.S. Patent Application Publication Number 2009/0308582, titled Heat Exchanger, filed on Jun. 15, 2009, which is incorporated herein by reference.
[0042] The tubes 64 and the tube sheets 68 , 72 are preferably made of the same material, such as, for example, aluminum, aluminum alloy, or marine-grade aluminum alloy. Aluminum and most of its alloys, as well as high alloy stainless steels and titanium, are amenable to the use of the FSW joining technique. The tubes and tube sheets can also be made from other materials such as metals including, but not limited to, high alloy stainless steels, carbon steels, titanium, copper, and bronze, and non-metal materials including, but not limited to, thermally enhanced polymers or thermoset plastics.
[0043] Other joining techniques can be used to secure the tubes and the tube sheets, such as expansion, press-fit, brazing, bonding, and welding (such as fusion welding and lap welding), depending upon the application and needs of the heat exchanger and the user.
[0044] In the example illustrated in FIGS. 2-4 , the tubes 64 are substantially round when viewed in cross-section and substantially linear from the end 66 to the end 70 . However, the shape of the tubes, when viewed in cross-section, can be square or rectangular, triangular, oval shaped, or any other shape, and combinations thereof. In addition, the tubes need not be linear from end to end, but can instead be curved, helical, and other shape deviating from linear. A total of seven tubes 64 are illustrated in this example. However, it is to be realized that a smaller or larger number of tubes can be provided.
[0045] It is preferred that the tubes be made of a material, such as a metal like aluminum, that permits extrusion or other seamless formation of the tubes. By eliminating seams from the tubes, corrosion is minimized.
[0046] The tube bundle 54 also includes a baffle assembly 80 integrated therewith. In the illustrated embodiment, the baffle assembly 80 is formed by a plurality of discrete (i.e. separate) heat transfer units 82 that are connected to each other so that the baffle assembly 80 has a substantially helix-shape that extends along the majority of the length of the tube bundle 54 around the longitudinal axis of the tube bundle. More preferably the helix-shaped baffle assembly 80 formed by the heat transfer units 82 extends substantially the entire axial length of the tube bundle.
[0047] The baffle assembly 80 increases the interaction time between the second fluid in the interior chamber of the shell and the walls of the tubes 64 . Further, as described further below, the heat transfer units 82 forming the baffle assembly are made of material that is thermally conductive, so that the baffle assembly 80 effectively increases the amount of surface area for thermal contact between the tubes and the second fluid. In addition, the substantially helix-shaped baffle assembly 80 substantially reduces or even eliminates dead spots in the interior chamber of the shell. The helix-shaped baffle assembly 80 can reduce pressure drop, reduce flow restriction of the fluid, and reduce the required force of pumping, yet at the same time provide directional changes of the second fluid to increase interaction between the second fluid and the tubes. Thus, the baffle assembly 80 provides the heat exchanger 50 with greater overall heat transfer efficiency between the second fluid and the tubes.
[0048] In an embodiment, the heat transfer units 82 can be strengthened by the use of solid or perforated plates, made from a thermally conductive material such as aluminum, affixed to the heat transfer units 82 . The plates can be affixed to the units 82 in a periodic pattern along the helix, or they can be affixed to the units in any arrangement one finds provides a suitable strengthening function. The plates can be used to assist in the assembly of the tube bundle and the heat exchanger, and can assist with minimizing the pressure drop on the shell-side flow. FIG. 18 shows an example of such a plate.
[0049] Referring to FIG. 5 together with FIGS. 2-4 , each heat transfer unit 82 comprises a generally wedge-shaped, planar body 84 having a generally triangular or pie-shape that has radiused inner surfaces to fit the curvature of the outer surfaces of the tubes. As described further below, the unit 82 includes a foam material such as graphite foam or metal foam. Preferably, the unit 82 consists essentially of the foam material, and more preferably consists of the foam material.
[0050] The body 84 includes a first major surface 86 and a second major surface 88 opposite the first major surface. In the illustrated embodiment, the major surfaces 86 , 88 are substantially planar. However, one or more of the major surfaces 86 , 88 need not be planar and could have contours or be shaped in a manner to facilitate fluid flow across or past the unit 82 . Fin patterns shown in FIGS. 17A-17F could be used to enhance flow and heat transfer over the major surfaces 86 , 88 . The fins could extend substantially perpendicular to the surfaces 86 , 88 . Alternatively, certain edges of the body 84 could have fin patterns shown in FIG. 17A thru 17 F to enhance flow and heat transfer from the edges of the heat transfer unit. A support rod hole 90 extends through the body 84 from the first major surface 86 to the second major surface 88 for receipt of a support rod described below. In another embodiment, an open-ended slot is used instead of the hole 90 to receive the support rod. Therefore, any opening, such as a hole or slot, could be used to receive the support rod.
[0051] The perimeter of the body 84 is defined by an arcuate radially outer edge 92 connected to linear side edges 94 , 96 at opposite ends of the outer edge. The side edges 94 , 96 converge toward a common center 98 which is removed during formation of the unit 82 . The side edges 94 , 96 terminate at radiused tube contact surfaces 100 , 102 , respectively, that are positioned on the body 84 opposite the radially outer edge 92 .
[0052] Each of the contact surfaces 100 , 102 is configured to connect to an outer surface of one of the tubes 64 for establishing thermal contact between the heat transfer unit 82 and the tubes. To maximize thermal contact, the contact surfaces 100 , 102 are configured to match the outer surface of the tubes 64 . In the illustrated embodiment, the contact surfaces 100 , 102 are curved, arcuate, or radiused to generally match a portion of the outer surface of the tubes 64 . However, the contact surfaces 100 , 102 can have any shape that corresponds to the shape of the tubes, for example square or rectangular, triangular, oval, or any other shape, and combinations thereof.
[0053] The body 84 also includes a finger section 104 that in use extends between the two tubes 64 engaged with the contact surfaces 100 , 102 . The finger section 104 includes linear edges 106 , 108 that extend from the contact surfaces 100 , 102 and that terminate at a third tube contact surface 110 that is configured to contact an outer surface of a third tube 64 for establishing thermal contact with the third tube. The contact surface 110 is configured to match the outer surface of the third tube. In the illustrated embodiment, the contact surface is slightly curved or arcuate to generally match a portion of the outer surface of the third tube. However, the contact surface 110 can have any shape that corresponds to the shape of the third tube, for example square or rectangular, triangular, oval, or any other shape, and combinations thereof. In certain embodiments, for example where contact between the body 84 and a third tube is not desired or where there is insufficient space between the tubes for the finger section to extend through, the finger section 104 can be eliminated.
[0054] FIGS. 3 and 4 show the heat transfer units 82 mounted in position on the tube bundle 54 . As shown in FIG. 3 , a plurality of support rods 120 are mounted at one end thereof to the tube sheet 72 and extend substantially parallel to the tubes 64 . The opposite ends of the support rods 120 are unsupported and not fixed to the tube sheet 68 . In another embodiment, the opposite ends of the support rods are also fixed to the tube sheet 68 . In the illustrated embodiment, four support rods 120 are provided and are evenly spaced around the tube bundle 54 . However, a larger or smaller number of support rods 10 can be used based in part on the size of the heat transfer units 82 that are used.
[0055] The heat transfer units 82 are mounted on the tube bundle 54 with the outer edges 92 thereof facing radially outward. A support rod 120 extends through the hole 90 or other opening and the tube contact surfaces 100 , 102 , 110 are in thermal contact with outer surfaces of three separate tubes 64 . When in thermal contact with the tubes, the major surfaces 86 , 88 form heat transfer surfaces that extend substantially radially from the outer surfaces of the tubes. As used herein, “in thermal contact” includes direct or indirect contact between the tube contact surfaces and the tubes to permit transfer of thermal energy between the tube contact surfaces and the tubes. Indirect contact between the tube contact surfaces and the tubes could result from the presence of, for example, an adhesive or other material between the tube contact surfaces and the surfaces of the tubes. When a hole is used, the hole 90 is preferably sized such that a relatively tight friction fit is provided with the support rod 120 to prevent axial movement of the heat transfer unit on the rod. If desired, fixation of the heat transfer unit 82 on the rod 120 can be supplemented by fixation means, for example an adhesive between the hole 90 and the rod. Instead of the hole, a slot can be formed that receives the support rod which can be secured via a friction fit or bonded using an adhesive.
[0056] If adhesive bonding is used, the adhesive can be thermally conductive. The thermal conductivity of the adhesive can be increased by incorporating ligaments of highly conductive graphite foam, with the ligaments in contact with the surfaces heat transfer unit(s) and the tubes, and the adhesive forming a matrix around the ligaments to keep the ligaments in intimate contact with the tubes and heat transfer units. The ligaments will also enhance bonding strength by increasing resistance to shear, peel and tensile loads.
[0057] As best seen in FIG. 4 , the heat transfer units 82 are arranged in a helical manner to form the baffle assembly 80 . Each heat transfer unit is axially and rotationally offset from an adjacent heat transfer unit with a small overlap region 122 between each pair of adjacent heat transfer units. Because of the overlap regions 122 , the baffle assembly formed by the heat transfer units is substantially continuous along the length of the tube bundle 54 . The amount of overlap provided in the region 122 can vary based on the size and depth or thickness of the heat transfer units. In the overlap regions 122 the adjacent heat transfer units can be secured together. For example, the heat transfer units 82 can be frictionally engaged in the overlap regions so that friction maintains the relative rotational positions of the heat transfer units. Alternatively, an adhesive or other fixation technique can be provided at the overlap regions to fix the relative rotational positions of the heat transfer units.
[0058] The periodicity of the helix can be changed by altering the angle of rotation of the heat transfer units. For example, the helix can have an angle of 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees and other angles. A person having ordinary skill in the art can determine the desired angles of rotation depending upon, for example, the desired performance of the heat exchanger.
[0059] In addition, as discussed above, a metal plate ( FIG. 18 ) can be used to strengthen the foam heat transfer units 82 and assist in fabrication of the tube bundle. The support plate can also be embedded within the foam heat transfer unit 82 during formation of the heat transfer units 82 . The metal plate secures the positioning of the tubes in a fixed pattern as an alternating baffle that travels in a helical pattern down the tube axes. The metal plate can be used to overlap two or more foam pieces to provide strength of the graphite core assembly.
[0060] When the tube bundle is installed in the shell 52 , the heat transfer units 82 are also sized such that the radially outer edges 92 thereof are positioned closely adjacent to, or in contact with, the interior surface of the shell to minimize or prevent the second fluid flowing in the shell from flowing between the radially outer edges 92 and the interior surface. This forces the majority of the fluid to flow past the tubes 64 in a generally spiral flow path defined by the heat transfer units 82 . In some embodiments, the heat transfer units 82 need not overlap, but can instead be sized and mounted so as to have gaps between adjacent heat transfer units to permit some of the fluid to flow axially between the adjacent heat transfer units.
[0061] The unit 82 (as well as the heat transfer units described below) includes, consists essentially of, or consists entirely of, a foam material such as graphite foam or metal foam. The term foam material is used herein to describe a material having closed cells, open cells, coarse porous reticulated structure, and/or combinations thereof. Examples of metal foam include, but are not limited to, aluminum foam, titanium foam, bronze foam or copper foam. In an embodiment, the foam material does not include metal such as aluminum, titanium, bronze or copper.
[0062] In one embodiment, the foam material is preferably graphite foam having an open porous structure. Graphite foam is advantageous because graphite foam has high thermal conductivity, a mass that is significantly less than metal foam materials, and has advantageous physical properties, such as being able to absorb vibrations (e.g. sound). Graphite foam can be configured in a wide range of geometries based on application needs and/or heat transfer requirements. Graphite foam can be used in exemplary applications such as power electronics cooling, transpiration, evaporative cooling, radiators, space radiators, EMI shielding, thermal and acoustic signature management, and battery cooling.
[0063] FIGS. 6A-E depict an exemplary process of how the heat transfer units 82 can be made. It is to be realized that this process is exemplary only and that other processes can be used. The heat transfer units 82 can be made by a process that stamps a foam material into a plurality of the wedge-shaped bodies 84 . FIG. 6A shows a die 128 for simultaneously punching a plurality of the bodies 84 from a circular foam substrate 130 ( FIG. 6D ). In FIG. 6B , the foam substrate is shown as stamped by the die. FIG. 6C shows the stamped material being pulled up and transitioned with the press to force the foam from the die. FIGS. 6D and 6E show the foam pressed out of the die 128 , creating a plurality of the wedge-shaped bodies 84 . In the illustrated example, five wedge-shaped bodies 84 are formed with each stamping sequence. However, a smaller or larger number of bodies 84 can be formed if desired. A clover-leaf shaped remainder 132 is left at the center of the substrate 130 which can be discarded.
[0064] FIGS. 6D and 6E show the bodies 84 without the holes 90 . The holes 90 could be formed directly by the die 128 . Alternatively, if the die does not form the holes, the holes can be created in the bodies 84 after the stamping process through a separate machining process.
[0065] FIG. 7 shows another embodiment of a foam heat transfer unit 150 disposed on a tube 64 of a tube bundle of a shell-and-tube heat exchanger. The heat transfer unit 150 comprises a generally cylindrical body with a central passage through which the tube 64 extends. The heat transfer unit 150 is in thermal contact with, directly or indirectly, the outer surface of the tube 64 . The body of the heat transfer unit 150 includes opposite end surfaces 152 that form heat transfer surfaces extending substantially radially from the outer surface of the tube. The heat transfer unit 150 can be fixed on the tube to maintain the axial position thereof in any suitable manner, for example by a friction fit or by using an adhesive. Axially extending channels 154 are formed in the body that extend between the end surfaces 152 . The channels 154 are evenly circumferentially spaced from one another around the body. In the illustrated embodiment, four channels 154 are shown, although a smaller or larger number of channels 154 can be used.
[0066] In FIG. 7 , a pair of the heat transfer units 150 are shown disposed on the tube 64 , spaced from each other with an axial gap between the heat transfer units. The two heat transfer units are rotated, for example, approximately 45 degrees relative to each other. However, the rotational angle between the heat transfer units can be more or less than 45 degrees, with the angle chosen based on, for example, the number of grooves and the spacing of the heat transfer units on the tube 64 .
[0067] As shown by the arrows in FIG. 7 representing the flow of fluid, a fluid flowing through the channel 154 impacts the surface of the adjacent heat transfer unit between the channels 154 causing the fluid to change direction in order to flow into the channels 154 of the adjacent heat transfer unit 150 . Additional heat transfer units 150 can be disposed along the entire length of the tube 64 , spaced from each other and rotated relative to a preceding heat transfer unit, similar to that shown in FIG. 7 .
[0068] FIG. 8 shows an embodiment of a foam heat transfer unit 160 disposed around the tube 64 of a tube bundle of a shell-and-tube heat exchanger. The heat transfer unit 160 is configured as a cylindrical sleeve with at least one end surface 162 that forms a heat transfer surface extending substantially radially from the outer surface of the tube. The heat transfer unit 160 can extend along any length of the tube, and preferably extends along substantially the entire length of the tube. The heat transfer unit 160 can be fixed on the tube to maintain the axial position thereof in any suitable manner, for example by a friction fit or by using an adhesive. In another embodiment, the heat transfer unit 160 is formed by two or more semi-circular sections that are fixed to the outer surface of the tube to form a sleeve. In addition, the sections can be spaced from one another to form one or more grooves between the sections that extend along the axis of the tube 64 .
[0069] With each of the heat transfer units 150 , 160 , they can be used by themselves, with each other, or with the heat transfer units 82 . In addition, when the heat transfer units 150 , 160 are mounted on the tubes 64 , the outer surfaces of the heat transfer units 150 , 160 preferably are in thermal contact with, directly or indirectly, the outer surfaces of the heat transfer units 150 , 160 of one or more adjacent tubes 64 .
[0070] FIG. 9 shows an embodiment of a portion of a tube bundle 170 of a shell-and-tube heat exchanger with a plurality of tubes 172 similar in function to the tubes 64 . A plurality of identical foam heat transfer units 174 are illustrated as being engaged with the tubes 172 and spaced along the length of the tubes. The heat transfer units 174 have bodies that are constructed as cradles or frames so that each heat transfer unit 174 is configured to engage with a plurality of the tubes 172 . In particular, the body of each heat transfer unit 174 is formed with a pair of outer tube contact surfaces 176 a , 176 b and three inner tube contact surfaces 178 a , 178 b , 178 c . However, the heat transfer units 174 can be configured to engage with more or less tubes as well. Each heat transfer unit 174 also includes generally planar end surfaces that form heat transfer surfaces extending substantially radially from the outer surface of the tubes.
[0071] FIG. 9 shows a first set of the heat transfer units on one side of the tubes 172 with the outer contact surfaces 176 a , 176 b facing upward, and a second set of the heat transfer units on the opposite side of the tubes 172 with the outer contact surfaces 176 a , 176 b facing downward. The first set of heat transfer units is axially or longitudinally offset from the heat transfer units of the second set. In the embodiment illustrated in FIG. 9 , seven tubes 172 can be engaged with the heat transfer units 174 , including two tubes engaged with the tube contact surfaces 176 a , 176 b of the upper set, two tubes engaged with the tube contact surfaces 176 a , 176 b of the lower set, and three tubes engaged with the inner tube contact surfaces 178 a , 178 b , 178 c of the upper and lower set. It is to be realized that the heat transfer units 174 can be configured to engage with a larger or smaller number of tubes.
[0072] Depending upon the layout of the heat transfer units 174 , the heat transfer units can create offsets, spirals or other flow patterns, in either counter, co-current or cross-flow arrangements. FIGS. 17A-F illustrate examples of patterns formed by different configurations of the foam heat transfer units 174 from FIG. 9 . For example, as shown in FIG. 17A , the heat transfer units can be arranged into a baffled “offset” configuration. FIG. 17B shows the heat transfer units arranged disposed in an offset configuration. When viewed from the top, each of the heat transfer units may have the shape of, but not limited to, square, rectangular, circular, elliptical, triangular, diamond, or any combination thereof. FIG. 17C shows the heat transfer units arranged into a triangular-wave configuration. Other types of wave configurations, such as for example, square waves, sinusoidal waves, sawtooth waves, and/or combinations thereof are also possible. FIG. 17D shows the heat transfer units arranged into an offset chevron configuration. FIG. 17E shows the heat transfer units arranged into a large helical spiral. FIG. 17F shows the heat transfer units arranged into a wavy arrangement or individual helical spirals.
[0073] FIG. 10A shows another embodiment of a tube bundle that has a plurality of tubes 190 arranged with an equilateral triangular pitch (i.e. the space between the tubes is generally an equilateral triangle). FIG. 10B shows tubes 190 of a tube bundle arranged with a square pitch, while FIG. 10C shows tubes 190 of a tube bundle arranged with a staggered square pitch.
[0074] In FIGS. 10A-C , foam heat transfer units 192 are shaped to fit in the pitch space between the tubes. For example, as shown in FIG. 10A , foam heat transfer units 192 are disposed between the tubes 190 and have surfaces that are in thermal contact with the tubes. Each of the heat transfer units 192 comprises a generally triangular body, that can be radiused to the curvature of the tubes, with a generally triangular cross-section, and with the three surfaces of the triangular body in thermal contact with, directly or indirectly, three separate tubes 190 .
[0075] The heat transfer units 192 may be arranged as required for heat transfer efficiency and/or providing directional flow of the fluid outside the tubes 190 . For example, the heat transfer units 192 can be arranged in any configuration to mimic a helix, multiple helix, offset baffle, offset blocks, or other patterns as shown in FIGS. 17A-F .
[0076] A person of ordinary skill in the art would realize that the tubes can be arranged with other pitch shapes between the tubes, and that the foam heat transfer units can have other corresponding shapes as well.
[0077] With reference to FIGS. 11 and 12 , another embodiment of a shell-and-tube heat exchanger 200 is illustrated that employs a tube bundle that includes twisted tubes 202 together with a foam heat transfer unit 204 . This embodiment has a number of advantages, including strengthening the tube core, eliminating the need for baffles, minimizing vibrations, and enhancing heat transfer on both the tube side (i.e. on the helical tubes) and on the shell side (the foam heat transfer unit).
[0078] The heat exchanger 200 includes a shell 206 that has axial inlets and outlets at each end for a first fluid to flow into and out of the tubes 202 . Tubes sheets, similar to the tube sheets 68 , 72 would be provided at each end of the tube bundle, would be attached to each tube 202 , and would fit within and close off the ends of the shell 206 . The shell also includes a radial inlet 208 and a radial outlet 210 for a second fluid.
[0079] In this embodiment, the tubes 202 are twisted helically around the foam heat transfer unit 204 along the length of the heat transfer unit 204 . The heat transfer unit 204 comprises a central, solid body of foam such that at any cross-section of the tube bundle, the foam body forms a heat transfer surface extending substantially radially from the outer surface of the tube(s). In FIG. 11 , the heat transfer unit 204 is represented by the dashed line extending the length of the shell 206 . The dashed line is not intended to imply that the heat transfer unit 204 is broken into sections or is discontinuous (although it is possible that the heat transfer unit 204 could be broken into separate section or made discontinuous if desired). The helical arrangement of tubes 202 enhances heat flow between the fluid flowing in the tubes and the fluid flowing in the shell outside of the tubes, by breaking up boundary layers inside and/or outside the tubes and combining axial and radial flow of the fluid along and around the outer surface of the tubes. In addition, the use of a baffle can be eliminated if desired. Further, the tubes 202 could be twisted about their own axes as well.
[0080] Although FIGS. 11 and 12 show six tubes 202 , a smaller or larger number of tubes can be used. For example, as discussed further below with respect to FIGS. 13-15 , three tubes can be helically wound around a central, solid heat transfer unit.
[0081] FIG. 13 is a cross-sectional view of another embodiment of a tube bundle that contains many axial tubes 222 disposed in a shell 224 . Two different implementations of the twisted or helical tube concept are illustrated. The triangle 226 in FIG. 13 illustrates three tubes 228 helically twisted about a central, solid body foam heat transfer unit 230 . This is illustrated more fully in FIG. 14 which additionally shows an optional sleeve 232 disposed around the assembly formed by the tubes 228 and the heat transfer unit 230 to form a tube-within-a-tube construction. The heat transfer unit 230 comprises a central, solid body of foam such that at any cross-section, the foam body forms a heat transfer surface extending substantially radially from the outer surface of the tube(s). In FIG. 14 , the heat transfer unit 230 is represented by the dashed line extending the length of the sleeve 232 . The dashed line is not intended to imply that the heat transfer unit 230 is broken into sections or is discontinuous (although it is possible that the heat transfer unit 230 could be broken into separate section or made discontinuous if desired).
[0082] Returning to FIG. 13 , a hexagonal arrangement 240 of the twisted tube concept is illustrated and shown more fully in FIG. 15 . In the hexagonal arrangement 240 , a tube within a tube concept is provided similar to the single arrangement shown in FIG. 14 , wherein a hexagonal pattern of six tubes-within-tubes assemblies 242 are used. Each assembly 242 includes a plurality of tubes 244 , for example three tubes, helically twisted about a central, solid body foam heat transfer unit 246 , with the tubes 244 and the heat transfer unit 246 disposed within a larger fluid carrying tube 248 . So the first fluid flows within the tubes 244 as well as within the tubes 248 in contact with the outside surfaces of the tubes 244 .
[0083] This twisted tube concept can be used by itself or in combination with any of the embodiments previously described herein. For example, FIG. 9 shows an arrangement similar to FIG. 14 , with a plurality of the tubes 228 twisted helically around the heat transfer unit 230 , and the tubes 228 and unit 230 disposed inside one of the tubes 172 to function together with the heat transfer units 174 at increasing the effectiveness of the heat exchanger.
[0084] The heat transfer units 204 , 230 have been described above as being solid bodies. However, the heat transfer units 204 , 230 need not be solid. Instead, the heat transfer units 204 , 230 can function as fluid carrying fluid distribution tubes which would be useful for creating a baffle-less design in a spray evaporator. For example, with reference to FIG. 12 , the heat transfer unit 204 can carry a fluid and be configured to spray the fluid outward as shown by the arrows onto the surfaces of the tubes 202 . The sprayed fluid exchanges heat with the tube surfaces, causing some or all of the sprayed fluid to change phase into a vapor. Likewise, as illustrated by the arrows in FIGS. 13 and 14 , the heat transfer unit 230 can be configured to spray fluid outward onto the tubes. One can also alternate foam and spray tubes too in various configurations.
[0085] FIG. 16 illustrates another embodiment of a shell-and-tube heat exchanger that uses rectangular blocks of foam heat transfer units 300 that are in thermal contact with, directly or indirectly, a plurality of axial tubes 302 . The blocks would extend some or all of the axial length of the tubes 302 . The blocks form a staggered diagonal baffle arrangement which is useful in applications where the second fluid flows in a cross-flow direction relative to the flow of the first fluid through the tubes 302 . However, other heat transfer unit configurations and arrangements, as well as other flow patterns, are possible.
[0086] All of the shell-and-tube heat exchangers described herein operate as follows. A first fluid is introduced into one axial end of the tubes of the tube bundles, with the fluid flowing through the tubes to an outlet end where the first fluid exits the heat exchanger. The tubes can be single pass or multi-pass. Simultaneously, a second fluid is introduced into the shell. The second fluid can flow counter to the first fluid, in the same direction as the first fluid, or in a cross-flow direction relative to the flow direction of the first fluid. As the second fluid flows through the shell, it contacts the outer surfaces of the tubes and/or the surfaces of the heat transfer units. Because the first fluid flows within the tubes, separated from the second fluid, heat is exchanged between the first and second fluids.
[0087] Depending upon the application, the first fluid can be at a higher temperature than the second fluid, in which case heat is transferred from the first fluid to the second fluid via the tubes and the heat transfer units. Alternatively, the second fluid can be at a higher temperature than the first fluid, in which case heat is transferred from the second fluid to the first fluid via the tubes and the heat transfer units.
[0088] The first and second fluids can be either liquids, gases/vapor or a binary mixture thereof. One example of a first fluid is water, such as sea water, and one example of a second fluid is ammonia in liquid or vapor form, which can be used in an Ocean Thermal Energy Conversion system.
[0089] The examples disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
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Shell-and-tube heat exchangers that utilize one or more foam heat transfer units engaged with the tubes to enhance the heat transfer between first and second fluids. The foam of the heat transfer units can be any thermally conductive foam material that enhances heat transfer, for example graphite foam. These shell-and-tube heat exchangers are highly efficient, inexpensive to build, and corrosion resistant. The described heat exchangers can be used in a variety of applications, including but not limited to, low thermal driving force applications, power generation applications, and non-power generation applications such as refrigeration and cryogenics. The foam heat transfer units can be made from any thermally conductive foam material including, but not limited to, graphite foam or metal foam. In an embodiment, the heat exchanger utilizes tubes that are twisted around a central foam heat transfer unit.
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RELATED APPLICATIONS
This application is a Division of U.S. patent application Ser. No. 09/790,036, filed Feb. 20, 2001, now U.S. Pat. No. 6,933,331, which is a continuation-in-part of U.S. application Ser. No. 09/753,806, filed Jan. 3, 2001, now U.S. Pat. No. 6,513,362, which is a Division of U.S. application Ser. No. 09/083,893, filed May 22, 1998, now U.S. Pat. No. 6,228,904, which is incorporated herein by reference, which is a Division of U.S. application Ser. No. 09/074,534, filed May 7, 1998, now U.S. Pat. No. 6,202,471, which claims priority from Provisional Application No. 60/079,225, filed Mar. 24, 1998, now expired, which claims priority from Provisional Application No. 60/069,935, filed Dec. 17, 1997, now expired, which claims priority from Provisional Application No. 60/049,077, filed Jun. 9, 1997, now expired, which is a continuation-in-part of U.S. application Ser. No. 08/739,257, filed Oct. 30, 1996, now U.S. Pat. No. 5,905,000, which is a continuation-in-part of U.S. application Ser. No. 08/730,661, filed Oct. 11, 1996, now U.S. Pat. No. 5,952,040, which is a continuation-in-part of U.S. application Ser. No. 08/706,819, filed Sep. 3, 1996, now U.S. Pat. No. 5,851,507, which is a continuation-in-part of U.S. application Ser. No. 08/707,341, filed Sep. 3, 1996, now U.S. Pat. No. 5,788,738.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of nanoscale powders as a component of novel composites and devices. By incorporating powders having dimensions less than a characteristic domain size into polymeric and other matrices, nanocomposites with unique properties can be produced.
2. Relevant Background
A very wide variety of pure phase materials such as polymers are now readily available at low cost. However, low cost pure phase materials are somewhat limited in the achievable ranges of a number of properties, including, for example, electrical conductivity, magnetic permeability, dielectric constant, and thermal conductivity. In order to circumvent these limitations, it has become common to form composites, in which a matrix is blended with a filler material with desirable properties. Examples of these types of composites include the carbon black and ferrite mixed polymers that are used in toners, tires, electrical devices, and magnetic tapes.
The number of suitable filler materials for composites is large, but still limited. In particular, difficulties in fabrication of such composites often arise due to issues of interface stability between the filler and the matrix, and because of the difficulty of orienting and homogenizing filler material in the matrix. Some desirable properties of the matrix (e.g., rheology) may also be lost when certain fillers are added, particularly at the high loads required by many applications. The availability of new filler materials, particularly materials with novel properties, would significantly expand the scope of manufacturable composites of this type.
SUMMARY OF THE INVENTION
Briefly stated, the present invention is directed to optical filters and products wherein the presence of novel nanofillers enhance a wide range of properties. In another aspect, the present invention is directed to methods for preparing nanocomposites that enable nanotechnology applications offering advantages such as superior processability (rheology), electrical conductivity, optical clarity and superior functional performance. In an example method, nanofillers and a substance having a polymer are mixed. Both low-loaded and highly-loaded nanocomposites are contemplated. Nanoscale coated and un-coated fillers may be used. Nanocomposite films may be coated on substrates.
In one aspect, the invention comprises a nanostructured filler, intimately mixed with a matrix to form a nanostructured composite. At least one of the nanostructured filler and the nanostructured composite has a desired material property which differs by at least 20% from the same material property for a micron-scale filler or a micron-scale composite, respectively. The desired material property is selected from the group consisting of refractive index, transparency to light, reflection characteristics, resistivity, permittivity, permeability, coercivity, B-H product, magnetic hysteresis, breakdown voltage, skin depth, curie temperature, dissipation factor, work function, band gap, electromagnetic shielding effectiveness, radiation hardness, chemical reactivity, thermal conductivity, temperature coefficient of an electrical property, voltage coefficient of an electrical property, thermal shock resistance, biocompatibility and wear rate.
The nanostructured filler may comprise one or more elements selected from the s, p, d, and f groups of the periodic table, or it may comprise a compound of one or more such elements with one or more suitable anions, such as aluminum, antimony, boron, bromine, carbon, chlorine, fluorine, germanium, hydrogen, indium, iodine, nickel, nitrogen, oxygen, phosphorus, selenium, silicon, sulfur, or tellurium. The matrix may be a polymer (e.g., poly(methyl methacrylate), poly(vinyl alcohol), polycarbonate, polyalkene, or polyaryl), a ceramic (e.g., zinc oxide, indium-tin oxide, hafnium carbide, or ferrite), or a metal (e.g., copper, tin, zinc, or iron). Loadings of the nanofiller may be as high as 95%, although loadings of 80% or less are preferred. The invention also comprises devices which incorporate the nanofiller (e.g., electrical, magnetic, optical, biomedical, and electrochemical devices).
Another aspect of the invention comprises a method of producing a composite, comprising blending a nanoscale filler with a matrix to form a nanostructured composite. Either the nanostructured filler or the composite itself differs substantially in a desired material property from a micron-scale filler or composite, respectively. The desired material property is selected from the group consisting of refractive index, transparency to light, reflection characteristics, resistivity, permittivity, permeability, coercivity, B-H product, magnetic hysteresis, breakdown voltage, skin depth, curie temperature, dissipation factor, work function, band gap, electromagnetic shielding effectiveness, radiation hardness, chemical reactivity, thermal conductivity, temperature coefficient of an electrical property, voltage coefficient of an electrical property, thermal shock resistance, biocompatibility, and wear rate. The loading of the filler does not exceed 95 volume percent, and loadings of 80 volume percent or less are preferred.
The composite may be formed by mixing a precursor of the matrix material with the nanofiller, and then processing the precursor to form a desired matrix material. For example, the nanofiller may be mixed with a monomer, which is then polymerized to form a polymer matrix composite. In another embodiment, the nanofiller may be mixed with a matrix powder composition and compacted to form a solid composite. In yet another embodiment, the matrix composition may be dissolved in a solvent and mixed with the nanofiller, and then the solvent may be removed to form a solid composite. In still another embodiment, the matrix may be a liquid or have liquid like properties.
Many nanofiller compositions are encompassed within the scope of the invention, including nanofillers comprising one or more elements selected from the group consisting of actinium, aluminum, arsenic, barium, beryllium, bismuth, cadmium, calcium, cerium, cesium, cobalt, copper, dysprosium, erbium, europium, gadolinium, gallium, gold, hafnium, hydrogen, indium, iridium, iron, lanthanum, lithium, magnesium, manganese, mendelevium, mercury, molybdenum, neodymium, neptunium, nickel, niobium, osmium, palladium, platinum, potassium, praseodymium, promethium, protactinium, rhenium, rubidium, scandium, silver, sodium, strontium, tantalum, terbium, thallium, thorium, tin, titanium, tungsten, vanadium, ytterbium, yttrium, zinc, and zirconium.
“Domain size” as that term is used herein, refers to the minimum dimension of a particular material morphology. In the case of powders, the domain size is the grain size. In the case of whiskers and fibers, the domain size is the diameter. In the case of plates and films, the domain size is the thickness.
As used herein, a “nanostructured powder” is one having a domain size of less than 100 nm, or alternatively, having a domain size sufficiently small that a selected material property is substantially different from that of a micron-scale powder, due to size confinement effects (e.g., the property may differ by 20% or more from the analogous property of the micron-scale material). Nanostructured powders often advantageously have sizes as small as 50 nm, 30 nm, or even smaller. Nanostructured powders may also be referred to as “nanopowders” or “nanofillers.” A nanostructured composite is a composite comprising a nanostructured phase dispersed in a matrix.
As it is used herein, the term “agglomerated” describes a powder in which at least some individual particles of the powder adhere to neighboring particles, primarily by electrostatic forces, and “aggregated” describes a powder in which at least some individual particles are chemically bonded to neighboring particles.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described with reference to the several figures of the drawing, in which,
FIG. 1 is a diagram of a nanostructured filler coated with a polymer;
FIG. 2 portrays an X-ray diffraction (XRD) spectrum for the stoichiometric indium tin oxide powder of Example 1;
FIG. 3 is a scanning electron microscope (SEM) micrograph of the stoichiometric indium tin oxide powder of Example 1; and
FIG. 4 is a diagram of the nanostructured varistor of Example 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Prior art filler materials for polymeric composites are usually powders with an average dimension in the range of 10–100 μm. Thus, each filler particle typically has on the order of 10 15 –10 18 atoms. In contrast the typical polymer chain has on the order of 10 3 –10 9 atoms. While the art of precision manufacturing of polymers at molecular levels is well-developed, the knowledge of precision manufacturing of filler materials at molecular levels has remained largely unexplored.
The number of atoms in the filler particles of the invention (hereinafter called “nanostructured filler” or “nanofiller”) is on the order of or significantly less than the number of atoms in the polymer molecules, e.g., 10 2 –10 10 . Thus, the filler particles are comparable in size or smaller than the polymer molecules, and therefore can be dispersed with orders of magnitude higher number density. Further, the fillers may have a dimension less than or equal to the critical domain sizes that determine the characteristic properties of the bulk composition; thus, the fillers may have significantly different physical properties from larger particles of the same composition. This in turn may yield markedly different properties in composites using nanofillers as compared to the typical properties of conventional polymer composites.
These nanostructured filler materials may also have utility in the manufacture of other types of composites, such as ceramic- or metal-matrix composites. Again, the changes in the physical properties of the filler particles due to their increased surface area and constrained domain sizes can yield changes in the achievable properties of composites.
The nanofillers of the invention can be inorganic, organic, or metallic, and may be in the form of powders, whiskers, fibers, plates or films. The fillers represent an additive to the overall composite composition, and may be used at loadings of up to 95% by volume. The fillers may have connectivity in 0, 1, 2, or 3 dimensions. Fillers may be produced by a variety of methods, such as those described in U.S. Pat. Nos. 5,486,675; 5,447,708; 5,407,458; 5,219,804; 5,194,128; and 5,064,464. Particularly preferred methods of making nanostructured fillers are described in U.S. patent application Ser. No. 09/046,465, by Bickmore, et al., filed Mar. 23, 1998, now U.S. Pat. No. 5,984,997 and Ser. No. 08/706,819, by Pirzada, et al., filed Sep. 3, 1996, now U.S. Pat. No. 5,851,507 both of which are incorporated herein by reference.
A wide variety of nanofiller compositions are possible. Some exemplary compositions include metals (e.g., Cu, Ag, Ni, Fe, Al, Pd, and Ti), oxide ceramics (e.g., TiO 2 , TiO 2-x , BaFe 2 O 4 , dielectric compositions, ferrites, and manganites), carbide ceramics (e.g., SiC, BC, TiC, WC, WCsub.1-x), nitride ceramics (e.g., Si 3 N 4 , TiN, VN, AlN, and Mo 2 N), hydroxides (e.g., aluminum hydroxide, calcium hydroxide, and barium hydroxide), borides (e.g., AlB 2 and TiB 2 ), phosphides (e.g., NiP and VP), sulfides (e.g., molybdenum sulfide, titanium sulfide, and tungsten sulfide), silicides (e.g., MoSi 2 ), chalcogenides (e.g., Bi 2 Te 3 , Bi 2 Se 3 ), and combinations of these.
The fillers are immediately mixed with a matrix material, which is preferably polymeric, but may also be ceramic, metallic, or a combination of the above. The matrix may be chosen for properties such as ease of processability, low cost, environmental benignity, commercial availability, and compatibility with the desired filler. The fillers are preferably mixed homogeneously into the matrix, but may also be mixed heterogeneously if desired, for example to obtain a composite having a gradient of some property. Mixing techniques for incorporating powders into fluids and for mixing different powders are well known in the art, and include mechanical, thermal, electrical, magnetic, and chemical momentum transfer techniques, as well as combinations of the above.
The viscosity, surface tension, and density of a liquid matrix material can be varied for mixing purposes, the preferred values being those that favor ease of mixing and that reduce energy needed to mix without introducing any undesirable contamination. One method of mixing is to dissolve the matrix in a solvent which does not adversely affect the properties of the matrix or the filler and which can be easily removed and recovered. Another method is to melt the matrix, incorporate the filler, and cool the mixture to yield a solid composite with the desired properties. Yet another method is to synthesize the matrix in-situ with the filler present. For example, the nanofiller can be mixed with a liquid monomer, which can then be polymerized to form the composite. In this method, the filler may be used as a catalyst or co-catalyst for polymerization. The mixing may also be accomplished in the solid state, for example by mixing a powdered matrix composition with the filler, and then compacting the mixture to form a solid composite.
Mixing can be assisted using various secondary species such as dispersants, binders, modifiers, detergents, and additives. Secondary species may also be added to enhance one to more of the properties of the filler-matrix composite.
Mixing can also be assisted by pre-coating the nanofiller with a thin layer of the matrix composition or with a phase that is compatible with the matrix composition. Such a coated nanoparticle is illustrated in FIG. 1 , which shows a spherical nanoparticle 6 and a coating 8 . In one embodiment, when embedding nanofillers in a polymer matrix, it may be desirable to coat the filler particles with a related monomer. When mixing nanofillers into a ceramic matrix, pre-coating can be done by forming a ceramic layer around the nanoscale filler particle during or after the synthesis of the nanoscale filler, by methods such as partial oxidation, nitridation, carborization, or boronation. In these methods, the nanostructured filler is exposed to a small concentration of a precursor that reacts with the surface of the filler to form a ceramic coating. For example, a particle may be exposed to oxygen in order to create an oxide coating, to ammonia in order to create a nitride coating, to borane to create a boride coating, or to methane to create a carbide coating. It is important that the amount of precursor be small, to prevent thermal runaway and consequent conversion of the nanostructured filler into a ceramic particle.
In case of polymer matrix, the filler can be coated with a polymer or a monomer by numerous methods, for example, surface coating in-situ, spray drying a dispersion of filler and polymer solution, co-polymerization on the filler surface, and melt spinning followed by milling. A preferred method is surface coating in-situ. In this process, the filler is first suspended in demineralized water (or another solvent) and the suspension's pH is measured. The pH is then adjusted and stabilized with small addition of acid (e.g., acetic acid or dilute nitric acid) or base (e.g., ammonium hydroxide or dilute sodium hydroxide). The pH adjustment produces a charged state on the surface of the filler. Once a desired pH has been achieved, a coating material (for example, a polymer or other appropriate precursor) with opposite charge is introduced into the solvent. This step results in coupling of the coating material around the nanoscale filler and formation of a coating layer around the nanoscale filler. Once the layer has formed, the filler is removed from the solvent by drying, filtration, centrifugation, or any other method appropriate for solid-liquid separation. This technique of coating a filler with another material using surface charge can be used for a variety of organic and inorganic compositions.
When a solvent is used to apply a coating as in the in-situ surface coating method described above, the matrix may also be dissolved in the solvent before or during coating, and the final composite formed by removing the solvent.
A very wide range of material properties can be engineered by the practice of the invention. For example, electrical, magnetic, optical, electrochemical, chemical, thermal, biomedical, and tribological properties can be varied over a wider range than is possible using prior art micron-scale composites.
Nanostructured fillers can be used to lower or raise the effective resistivity, effective permittivity, and effective permeability of a polymer or ceramic matrix. While these effects are present at lower loadings, they are expected to be most pronounced for filler loadings at or above the percolation limit of the filler in the matrix (i.e., at loadings sufficiently high that electrical continuity exists between the filler particles). Other electrical properties which may be engineered include breakdown voltage, skin depth, curie temperature, temperature coefficient of electrical property, voltage coefficient of electrical property, dissipation factor, work function, band gap, electromagnetic shielding effectiveness and degree of radiation hardness. Nanostructured fillers can also be used to engineer magnetic properties such as the coercivity, B-H product, hysteresis, and shape of the B-H curve of a matrix.
An important characteristic of optical material is its refractive index and its transmission and reflective characteristics. Nanostructured fillers may be used to produce composites with refractive index engineered for a particular application. Gradient lenses may be produced using nanostructured materials. Gradient lenses produced from nanostructured composites may reduce or eliminate the need for polishing lenses. The use of nanostructured fillers may also help filter specific wavelengths. Furthermore, a key advantage of nanostructured fillers in optical applications is expected to be their enhanced transparency because the domain size of nanostructured fillers ranges from about the same as to more than an order of magnitude less than visible wavelengths of light.
The high surface area and small grain size of nanofilled composites make them excellent candidates for chemical and electrochemical applications. When used to form electrodes for electrochemical devices, these materials are expected to significantly improve performance, for example by increasing power density in batteries and reducing minimum operating temperatures for sensors. (An example of the latter effect can be found in copending and commonly assigned U.S. application Ser. No. 08/739,257, “Nanostructured Ion Conducting Solid Electrolytes,” by Yadav, et al. now U.S. Pat. No. 5,905,000). Nanostructured fillers are also expected to modify the chemical properties of composites. These fillers are catalytically more active, and provide more interface area for interacting with diffusive species. Such fillers may, for example, modify chemical stability and mobility of diffusing gases. Furthermore, nanostructured fillers may enhance the chemical properties of propellants and fuels.
Many nanostructured fillers have a domain size comparable to the typical mean free path of phonons at moderate temperatures. It is thus anticipated that these fillers may have dramatic effects on the thermal conductivity and thermal shock resistance of matrices into which they are incorporated.
Nanostructured fillers—in coated and uncoated form—and nanofilled composites are also expected to have significant value in biomedical applications for both humans and animals. For example, the small size of nanostructured fillers may make them readily transportable through pores and capillaries. This suggests that the fillers may be of use in developing novel time-release drugs and methods of administration and delivery of drugs, markers, and medical materials. A polymer coating can be utilized either to make water-insoluble fillers into a form that is water soluble, or to make water-soluble fillers into a form that is water insoluble. A polymer coating on the filler may also be utilized as a means to time drug-release from a nanoparticle. A polymer coating may further be used to enable selective filtering, transfer, capture, and removal of species and molecules from blood into the nanoparticle.
A nanoparticulate filler for biomedical operations might be a carrier or support for a drug of interest, participate in the drug's functioning, or might even be the drug itself. Possible administration routes include oral, topical, and injection routes. Nanoparticulates and nanocomposites may also have utility as markers or as carriers for markers. Their unique properties, including high mobility and unusual physical properties, make them particularly well-adapted for such tasks.
In some examples of biomedical functions, magnetic nanoparticles such as ferrites may be utilized to carry drugs to a region of interest, where the particles may then be concentrated using a magnetic field. Photocatalytic nanoparticles can be utilized to carry drugs to region of interest and then photoactivated. Thermally sensitive nanoparticles can similarly be utilized to transport drugs or markers or species of interest and then thermally activated in the region of interest. Radioactive nanoparticulate fillers may have utility for chemotherapy. Nanoparticles suitably doped with genetic and culture material may be utilized in similar way to deliver therapy in target areas. Nanocomposites may be used to assist in concentrating the particle and then providing the therapeutic action. To illustrate, magnetic and photocatalytic nanoparticles may be formed into a composite, administered to a patient, concentrated in area of interest using magnetic field, and finally activated using photons in the concentrated area. As markers, nanoparticulate fillers—coated or uncoated—may be used for diagnosis of medical conditions. For example, fillers may be concentrated in a region of the body where they may be viewed by magnetic resonance imaging or other techniques. In all of these applications, the possibility exists that nanoparticulates can be released into the body in a controlled fashion over a long time period, by implanting a nanocomposite material having a bioabsorbable matrix, which slowly dissolves in the body and releases its embedded filler.
As implants, nanostructured fillers and composites are expected to lower wear rate and thereby enhance patient acceptance of surgical procedures. Nanostructured fillers may also be more desirable than micron-scale fillers, because the possibility exists that their domain size may be reduced to low enough levels that they can easily be removed by normal kidney action without the development of stones or other adverse side effects. While nanoparticulates may be removed naturally through kidney and other organs, they may also be filtered or removed externally through membranes or otherwise removed directly from blood or tissue. Carrier nanoparticulates may be reactivated externally through membranes and reused; for example, nutrient carriers may be removed from the bloodstream, reloaded with more nutrients, and returned to carry the nutrients to tissue. The reverse process may also be feasible, wherein carriers accumulate waste products in the body, which are removed externally, returning the carriers to the bloodstream to accumulate more waste products.
In some embodiments, the nanofiller particles have an aspect ratio ranging from 1 to 3.
EXAMPLES
Example 1
Indium Tin Oxide fillers in PMMA
A stoichiometric (90 wt % In203 in SnO 2 ) indium tin oxide (ITO) nanopowder was produced using the methods of copending patent application Ser. No. 09/046,465. 50 g of indium shot was placed in 300 ml of glacial acetic acid and 10 ml of nitric acid. The combination, in a 1000 ml Erlenmeyer flask, was heated to reflux while stirring for 24 hours. At this point, 50 ml of HNO 3 was added, and the mixture was heated and stirred overnight. The solution so produced was clear, with all of the indium metal dissolved into the solution, and had a total final volume of 318 ml. An equal volume (318 mL) of 1-octanol was added to the solution along with 600 mL ethyl alcohol in a 1000 mL HDPE bottle, and the resulting mixture was vigorously shaken. 11.25 ml of tetrabutyltin was then stirred into the solution to produce a clear indium/tin emulsion. When the resulting emulsion was burned in air, it produced a brilliant violet flame. A yellow nanopowder residue was collected from the flamed emulsion. The nanopowder surface area was 13.5 m 2 /gm, and x-ray diffractometer mean grain size was 60 nm.
FIG. 2 shows the measured X-ray diffraction (XRD) spectrum for the powder, and FIG. 3 shows a scanning electron microscope (SEM image of the powder. These data show that the powder was of nanometer scale.
The nanostructured powder was then mixed with poly(methyl methacrylate) (PMMA) in a ratio of 20 vol % powder to 80 vol % PMMA. The powder and the polymer were mixed using a mortar and pestle, and then separated into three parts, each of which was pressed into a pellet. The pellets were pressed by using a Carver hydraulic press, pressing the mixture into a ¼ inch diameter die using a 1500 pound load for one minute.
After removal from the die, the physical dimensions of the pellets were measured, and the pellets were electroded with silver screen printing paste (Electro Sciences Laboratory 9912-F).
Pellet resistances were measured at 1 volt using a Megohmmeter/IR tester 1865 from QuadTech with a QuadTech component test fixture. The volume resistivity was calculated for each pellet using the standard relation,
ρ
=
R
(
A
t
)
(
1
)
where ρ represents volume resistivity in ohm-cm, R represents the measured resistance in ohms, A represents the area of the electroded surface of the pellet in cm 2 , and t represents the thickness of the pellet in cm. The average volume resistivity of the stoichiometric ITO composite pellets was found to be 1.75×10 4 ohm-cm.
Another quantity of ITO nanopowder was produced as described above, and was reduced by passing 2 SCFM of forming gas (5% hydrogen in nitrogen) over the powder while ramping temperature from 25° C. to 250° C. at 5° C./min. The powder was held at 250° C. for 3 hours, and then cooled back to room temperature. The XRD spectrum of the resulting powder indicated that the stoichiometry of the reduced powder was In 18 SnO 29-x , with x greater than 0 and less than 29.
The reduced ITO nanopowder was combined with PMMA in a 20:80 volume ratio and formed into pellets as described above. The pellets were electroded as described, and their resistivity was measured. The average resistivity for the reduced ITO composite pellets was found to be 1.09×10 4 ohm-cm.
For comparison, micron scale ITO was purchased from Alfa Aesar (catalog number 36348), and was formed into pellets with PMMA and electroded as described above. Again, the volume fraction of ITO was 20%. The average measured resistivity of the micron scale ITO composite pellets was found to be 8.26×10 8 ohm-cm, representing a difference of more than four orders of magnitude from the nanoscale composite pellets. It was thus established that composites incorporating nanoscale fillers can have unique properties not achievable by prior art techniques.
Example 2
Hafnium Carbide Fillers in PMMA
Nanoscale hafnium carbide fillers were prepared as described in copending U.S. patent application Ser. Nos. 08/706,819 and 08/707,341. The nanopowder surface area was 53.5 m 2 /gm, and mean grain size was 16 nm. Micron scale hafnium carbide powder was purchased from Cerac (catalog number H-1004) for comparison.
Composite pellets were produced as described in Example 1, by mixing filler and polymer with a mortar and pestle and pressing in a hydraulic press. Pellets were produced containing either nanoscale or micron scale powder at three loadings: 20 vol % powder, 50 vol % powder, and 80 vol % powder. The pellets were electroded as described above, and their resistivities were measured. (Because of the high resistances at the 20% loading, these pellets' resistivities were measured at 100V. The other pellets were measured at IV, as described in Example 1).
Results of these resistivity measurements are summarized in Table 1. As can be seen, the resistivity of the pellets differed substantially between the nanoscale and micron scale powders. The composites incorporating nanoscale powder had a somewhat decreased resistivity compared to the micron scale powder at 20% loading, but had a dramatically increased resistivity compared to the micron scale powder at 50% and 80% loading.
TABLE 1
Volume %
Resistivity of nanoscale
Resistivity of micron scale
filler
powder composite (ohm-cm)
powder composite (ohm-cm)
20
5.54 × 10 12
7.33 × 10 13
50
7.54 × 10 9
2.13 × 10 4
80
3.44 × 10 9
1.14 × 10 4
Example 3
Copper Fillers in PMA and PVA
Nanoscale copper powders were produced as described in U.S. patent application Ser. Nos. 08/706,819 and 08/707,341. The nanopower surface area was 28.1 m2/gm, and mean grain size was 22 nm. Micron scale copper powder was purchased from Aldrich (catalog number 32645-3) for comparison.
The nanoscale and micron scale copper powders were each mixed at a loading of 20 vol % copper to 80 vol % PMMA and formed into pellets as described above. In addition, pellets having a loading of 15 vol % copper in poly(vinyl alcohol) (PVA) were produced by the same method. The pellets were electroded and resistivities measured at 1 volt as described in Example 1. Results are shown in Table 2.
TABLE 2
Volume %
Volume Resistivity
Additive
Polymer
filler
(ohm-cm)
nanoscale copper
PMMA
20
5.68 × 10 10
nanoscale copper
PVA
15
4.59 × 10 5
micron scale copper
PMMA
20
4.19 × 10 12
It can be seen from Table 2 that the resistivity of the nanoscale copper powder/PMMA composite was substantially reduced compared to the micron scale copper powder/PMMA composite at the same loading, and that the resistivity of the nanoscale copper powder/PVA composite was lower still by five orders of magnitude.
Example 4
Preparation of Polymer-Coated Nanostructured Filler
The stoichiometric (90 wt % In 2 O 3 in SnO 2 ) indium tin oxide (ITO) nanopowder of Example 1 was coated with a polymer as follows.
200 milligrams of ITO nanopowders with specific surface area of 53 m 2 /gm were added to 200 ml of demineralized water. The pH of the suspension was adjusted to 8.45 using ammonium hydroxide. In another container, 200 milligrams of poly(methyl methacrylate) (PMMA) was dissolved in 200 ml of ethanol. The PMMA solution was warmed to 100° C. while being stirred. The ITO suspension was added to the PMMA solution and the stirring and temperature of 100° C. was maintained till the solution reduced to a volume of 200 ml. The solution was then cooled to room temperature to a very homogenous solution with very light clear-milky color. The optical clarity confirmed that the powders are still nanostructured. The powder was dried in oven at 120° C. and its weight was measured to be 400 milligrams. The increase in weight, uniformity of morphology and the optical clarity confirmed that the nanopowders were coated with PMMA polymer.
The electrochemical properties of polymer coated nanopowders were different than the as-produced nanopowders. The as-produced nanopowder when suspended in demineralized water yielded a pH of 3.4, while the polymer coated nanopowders had a pH of 7.51.
Example 5
Preparation of Electrical Device Using Nanostructured Fillers
A complex oxide nanoscale filler having the following composition was prepared: Bi 2 O 3 (48.8 wt %), NiO (24.4 wt %), CoO (12.2 wt %), Cr 2 O 3 (2.4 wt %), MnO (12.2 wt %), and Al 2 O 3 (<0.02 wt %). The complex oxide filler was prepared from the corresponding nitrates of the same cation. The nitrates of each constituent were added to 200 mL of deionized water while constantly stirring. Hydroxides were precipitated with the addition of 50 drops of 28–30% NH 4 OH. The solution was filtered in a large buchner funnel and washed with deionized water and then with ethyl alcohol. The powder was dried in an oven at 80° C. for 30 minutes. The dried powder was ground using a mortar and pestle. A heat treatment schedule consisting of a 15° C./min ramp to 350° C. with a 30 minute dwell was used to calcine the ground powder.
The nanofiller was then incorporated at a loading of 4% into a zinc oxide ceramic matrix. The composite was prepared by mechanically mixing the doped oxide nanofiller powder with zinc oxide powder, incorporating the mixture into a slurry, and screen printing the slurry (further described below). For comparison, devices were made using both a nanoscale matrix powder produced by the methods of copending and commonly assigned U.S. application Ser. No. 08/706,819, and using a micron scale matrix powder purchased from Chemcorp. The fillers and the matrix powders were mixed mechanically using a mortar and pestle.
Using the filler-added micron scale powder, a paste was prepared by mixing 4.0 g of powder with 2.1 g of a commercial screen printing vehicle purchased from Electro Science Laboratories (ESL vehicle 400). The doped nanoscale powder paste was made using 3.5 g powder and 3.0 g ESL vehicle 400. Each paste was mixed using a glass stir rod. Silver-palladium was used as a conducting electrode material. A screen with a rectangular array pattern was used to print each paste on an alumina substrate. First a layer of silver-palladium powder (the lower electrode) was screen printed on the substrate and dried on a hot plate. Then the ceramic filled powder was deposited, also by screen printing. Four print-dry cycles were used to minimize the possibility of pinhole defects in the varistor. Finally, the upper electrode was deposited.
The electrode/composite/electrode varistor was formed as three diagonally offset overlapping squares, as illustrated in FIG. 4 . The effective nanostructured-filler based composite area in the device due to the offset of the electrodes was 0.036 in 2 (0.2315 cm 2 ). The green thick films were co-fired at 900° C. for 60 minutes. The screen printed specimen is shown in FIG. 4 , where light squares 10 represent the silver-palladium electrodes, and dark square 12 represents the composite layer.
Silver leads were attached to the electrodes using silver epoxy. The epoxy was cured by heating at a 50° C./min ramp rate to 600° C. and then cooling to room temperature at a rate of 50° C./min. The TestPoint computer software, in conjunction with a Keithley® current source, was used to obtain a current-voltage curve for each of the varistors. Testpoint and Keithley are trademarks or registered trademark of Keithley Scientific Instruments, Inc.
The electrode/micron scale matrix composite/electrode based varistor device had a total thickness of 29–33 microns and a composite layer thickness of 19 microns. The electrode/nanoscale matrix composite/electrode based varistor device had a total thickness of 28–29 microns and a composite layer thickness of 16 microns. Examination of current-voltage response curves for both varistors showed that the nanostructured matrix varistor had an inflection voltage of about 2 volts, while the inflection voltage of the micron scale matrix varistor had an inflection voltage of about 36 volts. Fitting the current-voltage response curves to the standard varistor power-law equation
I=nV a (2)
yielded values of voltage parameter a of 2.4 for the micron-scale matrix device, and 37.7 for the nanoscale matrix device. Thus, the nonlinearity of the device was shown to increase dramatically when the nanoscale matrix powder was employed.
Example 6
Thermal Battery Electrode Using a Nanostructured Filler
Thermal batteries are primary batteries ideally suited for military ordinance, projectiles, mines, decoys, torpedoes, and space exploration systems, where they are used as highly reliable energy sources with high power density and extremely long shelf life. Thermal batteries have previously been manufactured using techniques that place inherent limits on the minimum thickness obtainable while ensuring adequate mechanical strength. This in turn has slowed miniaturization efforts and has limited achievable power densities, activation characteristics, safety, and other important performance characteristics. Nanocomposites help overcome this problem, as shown in the following example.
Three grams of raw FeS 2 powder was mixed and milled with a group of hard steel balls in a high energy ball mill for 30 hours. The grain size of produced powder was 25 nm. BET analysis showed the surface area of the nanopowder to be 6.61 m 2 /gm. The TEM images confirmed that the ball milled FeS 2 powder consists of the fine particles with the round shape, similar thickness and homogenous size. The cathode comprised FeS 2 nanopowders (68%), eutectic LiCl—KCl (30%) and SiO 2 (2%) (from Aldrich Chemical with 99% purity). The eutectic salts enhanced the diffusion of Li ions and acted as a binder. Adding silicon oxide particles was expected to immobilize the LiCl—KCl salt during melting. For comparison, the cathode pellets were prepared from nanostructured and micron scale FeS 2 powders separately.
To improve electrochemical efficiencies and increase the melting point of anode, we chose micron scale Li 44%–Si 56% alloy with 99.5% purity (acquired from Cyprus Foote Mineral) as the anode material in this work. A eutectic salt, LiCl 45%–KCl 55% (from Aldrich Chemical with 99% purity), was selected as electrolyte. The salt was dried at 90° C. and fused at 500° C. To strengthen the pellets and prevent flowing out of electrolyte when it melted, 35% MgO (Aldrich Chemical, 99% purity) powder was added and mixed homogeneously with the eutectic salt powder.
The pellets of anode electrodes were prepared by a cold press process. A hard steel die with a 20 mm internal diameter was used to make the thin disk pellets. 0.314 grams of Li 44%–Si 56% alloy powder (with 76–422 mesh particle size) was pressed under 6000 psi static pressure to form a pellet. The thickness and density of the pellets so obtained was determined to be 0.84 mm and 1.25 g/cm 2 , respectively. Electrolyte pellets were produced using 0.55 grams of blended electrolyte powder under 4000 psi static pressure. The thickness and density of the pellets obtained were 0.84 mm and 2.08 g/cm 2 respectively. The cathode pellet was prepared using 0.91 grams of mixed micron scale FeS 2 —LiCl—KCl—SiO 2 powder pressed under 4000 psi static pressure. The thickness and density of the pellets obtained were 0.86 mm and 3.37 g/cm 2 , respectively.
A computerized SOLARTRON® 1287 electrochemical interface and a 1260 Gain/Phase Analyzer were employed to provide constant current and to monitor variation in potential between anode and cathode of cells during the discharging. “Solartron” is a registered trademark of the Solartron Electronic Group, Ltd. The cutoff potential of discharge was set at 0.8 volt. The thermal battery with the nanocomposite cathode provided 1A constant current for 246 seconds, until the potential fell to 0.8 volt. It was observed that the power density of the nanostructured single cell thermal battery was 100% higher than that achievable with micron sized materials. Thus, nanoscale fillers can help enhance the electrochemical performance of such a device.
Example 7
A Magnetic Device Using Nanostructured Ferrite Fillers
Ferrite inductors were prepared using nanostructured and micron-scale powders as follows. One-tenth of a mole (27.3 grams) of iron chloride hexahydrate (FeCl 3 -6H 2 O) was dissolved in 500 ml of distilled water along with 0.025 moles (3.24 grams) of nickel chloride (NiCl 2 ) and 0.025 moles (3.41 grams) of zinc chloride (ZnCl 2 ). In another large beaker, 25 grams of NaOH was dissolved in 500 ml of distilled water. While stirring the NaOH solution rapidly, the metal chloride solution was slowly added, forming a precipitate instantaneously. After 1 minute of stirring, the precipitate solution was vacuum filtered while frequently rinsing with distilled water. After the precipitate had dried enough to cake and crack, it was transferred to a glass dish and allowed to dry for 1 hour in an 80° C. drying oven. At this point, the precipitate was ground with a mortar and pestle and calcined in air at 400° C. for 1 hour to remove any remaining moisture and organics.
BET analysis of the produced powder yielded a surface area of 112 m 2 /g, confirming the presence of nanometer-sized individual particles with an estimated BET particle size of 11 nm. XRD analyses of all nanoscale powders showed the formation of a single (Ni, Zn)Fe 2 O 4 ferrite phase with peak shapes characteristic of nanoscale powders. XRD peak broadening calculations reported an average crystallite size of 20 nm of the thermally quenched powders and 8 nm for the chemically derived powders. SEM-EDX analyses of sintered nanopowder pellets showed an average composition of 14.8% NiO, 15.8% ZnO, and 69.4% Fe 2 O 3 , which corresponded to the targeted stoichiometric composition of the Ni 0.5 Zn 0.5 Fe 2 O 4 .
Nanoscale ferrite filler powders were uniaxially pressed at 5000 pounds in a quarter-inch diameter die set into green pellets. The powders were mixed with 2 weight percent Duramax® binder for improved sinterability. The amount of powder used for pressing varied from 1.5 to 1.7 grams, typically resulting in cylinders having a post-sintered height of approximately 1.5 cm. To avoid cracking and other thermal stress effects, a multi-level heating profile was employed. The pellets were fired at a rate of 5° C./min to 300° C., 11° C./min to 600° C., and 20° C./min to the final sintering temperature, where it was held for four hours. Pellets were cooled from the sintering temperature at a rate of 10° C./min to ensure the sintering temperature ranged from 900° C. to 1300° C., but was typically greater than 1200° C. to ensure an acceptable density. Sintered pellets were then wound with 25 turns of 36 gauge enamel coated wire, the wire ends were stripped, and the completed solenoids where used for electrical characterization. An air coil was prepared for the purpose of calculating magnetic properties. This coil was created by winding 25 turns of the enamel coated wire around the die plunger used previously. This coil was taped with masking tape, slid off the plunger slowly to maintain shape and characteristics, and was characterized along with the ferrite solenoids.
Inductance characterization was performed with a Hewlett-Packard 429A RF Impedance/Materials Analyzer. Impedance, parallel inductance, q factor, and impedance resistance were measured over a logarithmic frequency sweep starting at 1 MHz and ending at 1.8 GHz. Values for permeability (μ) and loss factor (LF) were calculated from inductance (L), air coil inductance (L o ), and impedance resistance (R) using the following equations:
μ
=
L
L
0
(
3
)
LF
=
L
0
R
ω
L
2
(
4
)
Resistivity measurements were made with a Keithley® 2400 SourceMeter using a four-wire probe attachment and TestPoint™ data acquisition software. Voltage was ramped from 0.1 to 20 volts while simultaneously measuring current. The results were plotted as field (voltage divided by pellet thickness) versus current density (current divided by electrode cross sectional area). The slope of this graph gives material resistivity (ρ).
Table 3 summarizes electrical properties of inductors prepared from micron-sized powder or from nanopowder. In most cases there is an advantage to using nanoscale precursor powder instead of micron-sized powder. It is important to keep in mind that all measurements were taken from cylindrical devices, which have inherently inefficient magnetic properties. Solenoids of this shape were used in this study because of the ease of production and excellent reproducibility. All measured properties would be expected to improve with the use of higher magnetic efficiency shapes such as cores or toroids, or by improving the aspect ratio (length divided by diameter) of the cylindrical samples.
TABLE 3
Micron
Nano
Micron
Nano
Loss Factor @ 1 MHz
Critical Frequency
Average
0.0032
0.0025
Average
68.9 MHz
78.3 MHz
Q Factor @ 1 MHz
Resistivity
Average
37.2
52.2
Average
0.84 MΩ
33.1 MΩ
The inductors made from ferrite nanopowders exhibited significantly higher Q-factor, critical resonance frequency, and resistivity. They also exhibited more than 20% lower loss factor as is desired in commercial applications.
Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.
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Methods for preparing optical filter nanocomposites from nanopowders. Both low-loaded and highly-loaded nanocomposites are included. Nanoscale coated and un-coated fillers may be used. Nanocomposite filter layers may be prepared on substrates. Gradient nanocomposites for filters are discussed.
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[0001] The following disclosure is based on German Patent Application No. 10 2004 019 306.1 filed on Apr. 15, 2004, which is herewith incorporated into this application by explicit reference.
FIELD OF APPLICATION AND PRIOR ART
[0002] The invention relates to a roll or calender roll, as well as to a method for the manufacture of a roll.
[0003] In construction and process engineering use is frequently made of treatment devices such as punches or punch surfaces, presses or rotary rolls, which have a multilayer structure. Such a multilayer structure can be desired in order to achieve particular strength characteristics or behaviour. Cases can also arise in which already existing treatment devices have to be modified or reconstructed, for example provided with new surfaces. Difficulties more particularly arise if on an already existing covering or substructure a further layer structure has to be applied, whose mechanical characteristics do not necessarily bring about harmony or which cause difficulties.
[0004] One example is constituted by calender rolls, which have a covering as the top layer and which is made from a paper or textile material. There are in particular calender rolls, whose covering comprises a plurality of textile material or cotton fabric sheets, which are engaged on a metal core and strongly compressed in the axial direction. These rolls form a covering or surface having a certain elasticity and which is relatively favourable and in the case of wear can be dressed to a certain extent in order to once again obtain a uniform, smooth surface. In order to be able to use existing rolls for the formation of a new covering or layer system, attempts have been made to slide a precisely matching metal cylinder onto the textile layer and then apply thereto a layer of plastic or rubber for example. However, the problem arises that the diameter of the metal tube must precisely match the roll diameter, because otherwise mechanical problems arise.
Problem and Solution
[0005] The problem of the invention is to provide a roll and a method for the manufacture of the roll making it possible to avoid the problems of the prior art and which in particular enable in an inexpensive and technically advantageous manner to apply a further layer structure to existing treatment devices.
[0006] This problem is solved by a roll having the features of claim 1 and a method for the manufacture of a roll having the features of claim 20 . Advantageous and preferred developments of the invention form the subject matter of further claims and are explained in greater detail hereinafter. By express reference the wording of the claims is made into part of the content of the present description. Features concerning the technical design, as well as the treatment device, together with the method in part apply to both and are only explained once hereinafter. These explanations relate both to the treatment device and to the method.
[0007] According to the invention a treatment device has a hard substructure to which is applied a covering of paper or textile material having a certain thickness, more particularly several centimetres. The covering comprises a plurality of individual, thin paper or textile material layers. The latter are compressed or pressed together to give a certain dimensional stability. This paper or textile material covering undergoes surface structuring. To it is applied plastic, particularly a liquid plastic, which has the effect of an adhesive and also provides a mechanical connection, particularly for load transfer purposes. In turn to it is applied a fibrous material stabilizing layer. The latter is also impregnated with plastic, which cures and together with the fibrous material forms a stable, fibre-reinforced layer.
[0008] Thus, through the plastic and fibrous material is formed an intermediate layer, which in turn has an adequate strength. As a result of the structuring of the surface of the covering below the same it is once again ensured that the plastic deeply penetrates the paper or textile material and at least impregnates a portion thereof. This brings about a particularly good adhesion in addition to the actual structuring and also leads to a good mechanical connection, particularly for load transfer. Particularly in the case of paper or textile material as a result of structuring the surface can be opened, so that liquid plastic or adhesive can penetrate. As a result of the following stabilizing layer with fibrous material firstly a relatively smooth surface of the treatment device is again provided, so that the structuring is compensated and secondly a stable layer results from the composite of fibrous material and plastic or adhesive.
[0009] With particular preference the treatment device is a roll, particularly a calender roll, or this is used so that a new treatment device can be produced with the described method. After finishing as a calender roll, such a roll can form a rolling mill with a metal counterroll, for example for smoothing paper surfaces. Onto the previously described stabilizing layer a cover layer can be applied for this purpose and is advantageously made from plastic or rubber. It can have a thickness of a few millimetres to a few centimetres and can be adapted as regards its hardness and other properties to the intended use.
[0010] An advantageous textile material is cotton. More particularly the textile material comprises a cotton fabric, such as is used for jeans and the like. This permits a relatively favourable availability. Further possibilities are the provision of pieces of wool or synthetic fibres in the textile material, for example under the trade name Nomex.
[0011] A substructure of the treatment device or roll is preferably metallic in order to ensure an adequate strength. In particularly preferred manner it is a solid or hollow metal core, which in the case of a roll also forms the rotation axis.
[0012] Paper or textile material sheets can be applied to a substructure or in the case of a roll can be engaged on a roll core and in this way form the covering, being compressed or pressed together for this purpose. In the case of a roll this is advantageously brought about by tightening means at the ends, which can be nuts to be screwed on, for example.
[0013] The structuring of the surface of the covering can have grooves, for example, which can have a variable depth as a function of the covering thickness and other requirements. The depth can be between 3 and 20 mm, for example somewhat under 10 mm. It is considered advantageous to provide a uniform, unitary structuring, i.e. only having grooves. The latter can all be equidistant and are advantageously closely juxtaposed. As a result of a directly interconnecting application of the grooves, there is a very large number of these per surface unit and consequently there is a considerable adhesion-improving effect. This also improves the mechanical connection with respect to the load transfer. Thus, mechanical loads can be better transferred from the outer layer to the roll core.
[0014] In the case of a roll, preferably a surface structuring is such that it only runs in the rotation direction with no or only a limited longitudinal component, mainly in the axial direction of the roll. Otherwise in the case of rotating rolls, from a pressure along the nip line of a calender rolling mill a force and motion action of the top covering with deflection in the longitudinal direction of the axis could be brought about and this is obviously to be avoided. Thus, grooves run substantially or advantageously exclusively in the rotation direction in the form of closed, circular grooves. It is also possible to provide a groove in the form of a screw thread. As a result the indicated characteristics are still achieved, but not in quite such a satisfactory manner.
[0015] Another possibility for a surface structuring, which in certain circumstances can be provided in addition to the aforementioned elongated grooves is constituted by advantageously conical holes or depressions, which should be uniformly distributed. It is also advantageous and favourable from the manufacturing standpoint for them to have roughly the same size. They can be applied to rotating rolls by drills or arbors and in certain circumstances by laser beams.
[0016] The plastic or adhesive can be a resin, such as a synthetic resin, for example, or epoxy resin. A plastic can advantageously be a thermosetting plastic.
[0017] The fibrous material is advantageously constituted by very stable reinforcing fibres. They are with particular advantage applied in the form of rovings, that is a continuous fibre bundle. A fibrous material is preferably selected from the following group: glass, carbon, aramid or boron fibres.
[0018] The application of the fibrous material to a roll as the treatment device can take place by rotating the roll and winding on the fibrous material. On winding on the fibrous material it must be ensured that it is compressed and the fibres are applied uniformly and in closely juxtaposed manner. In a first pass it is possible to fill the grooves or depressions for obtaining a planar surface and then a further fibrous material layer can be applied. Alternatively and in a single pass the fibrous material can be applied in the desired thickness. It is considered advantageous if the fibrous material is applied already impregnated with liquid plastic or adhesive. Following the hardening of the plastic or adhesive a further covering can either be directly applied or firstly the surface is smoothed, for example abraded. The top covering can be constituted by a polymer material, for example rubber or plastic.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Embodiments of the invention are described in greater detail hereinafter relative to the attached drawings, wherein show:
[0020] FIG. 1 A calender roll with textile covering, which is provided with a surface structuring with grooves according to the invention by rotating.
[0021] FIG. 2 Alternative surface structurings with grooves and holes juxtaposed for comparison purposes.
[0022] FIG. 3 Several partial representations of a surface of a treatment device, for example a calender roll according to FIG. 1 , with the different processing steps.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] FIG. 1 shows a calender roll 1 comprising a plurality of sheets 13 of the aforementioned paper or textile material. The sheets 13 are engaged on a core 15 also having shaft ends. The paper sheets 13 are compressed by two holding disks 17 at the left and right-hand ends. In normal operation they form a smooth surface 19 , as can be seen to the left in FIG. 1 .
[0024] For the treatment according to the invention, using a cutting tool 21 and in accordance with a conventional turning process, the surface 19 or sheets 13 are treated, so as to cut in grooves 23 . The grooves 23 are precisely parallel, directly follow on to one another and always equidistantly spaced run precisely in the circumferential direction on roll 11 .
[0025] It is clear from the larger scale reproduction of groove structures in FIG. 2 how the same can be formed. As shown to the left, they can be constructed with gentle transitions and therefore also gentle or rounded tips or points 24 . As shown to the right, they can also be relatively acute angled. The flanks between the tips 24 and the lowest point of the grooves 23 are advantageously straight here, although this is not necessary.
[0026] On carefully working the surface 19 of roll 11 using cutting tool 21 , the outer edges of the individual sheets 13 do not become ragged and are instead cut relatively smooth. This means that they can be worked in the same way as a solid material. However, as a result of the working, the surface or overall surface formed of the directly following on outer edges of the sheets 13 acquire a structure which is opened from the outside or which is accessible for liquid, as will be explained hereinafter.
[0027] To the far right in FIG. 2 is shown as a further alternative a structuring where holes or blind holes 26 can be formed in the surface 19 . This can for example take place by drilling or with laser beams or the like. As shown, the holes can be in the form of purely cylindrical blind holes, but can also taper downwards.
[0028] FIG. 3 shows in a split representation the different steps illustrating how starting with a treatment device with grooves 23 , for example the calender roll 11 of FIG. 1 , the further layer structure can be applied. The basic surface structure is in accordance with FIG. 1 , in which the holding disks 17 are already provided with the grooves 23 .
[0029] In the first step according to FIG. 1 synthetic resin 30 is applied using a nozzle 32 . The nozzle 32 can be replaced by any other applicator. As shown to the right, in the second step application takes place so that at least the grooves 23 are relatively well covered with the synthetic resin 30 and are advantageously not completely filled. Synthetic resin can be applied at this time to the tips 24 . This is decisively dependent on the subsequent fibre application process.
[0030] In the third step in FIG. 3 rovings 34 comprising individual fibres 35 are wound on and can be applied in continuous form. As is apparent from the situation in the fourth step, the grooves 23 between the tips 24 are first roughly filled with the fibres 35 . Then, in the fifth step, once again fibrous material 34 , advantageously in the form of rovings 34 , is applied together with further synthetic resin, but on this occasion is distributed over the entire surface. Thus, whereas in the first step the fibrous material 35 equalizes or fills the grooves 23 compared with the intermediate tips 24 , now an entire covering fibrous material layer 35 is applied. This is used for strengthening the surface of the treatment device or roll 11 or the sheets 13 . A more stable and cohesive substructure can be created for a subsequent layer structure.
[0031] In the fifth step the entire roll 11 is covered with a layer of fibrous material 35 impregnated with synthetic resin 30 . This application of the layer or the production of the layer is to take place in such a way that the surface is already to some extent uniform and flat, either as a result of winding or subsequent working.
[0032] According to the next or sixth step, onto the completely cured fibre-reinforced synthetic resin material layer is applied a further polymer material covering 37 , for example of rubber or plastic, as a function of the intended use. This, however, corresponds to the known method. With regards to this functional polymer material layer 37 , as a result of the stable, intermediate, fibrous material layer 35 , the roll behaves in a neutral manner and its characteristics are no longer influenced or characterized by the underlying structure of paper sheets 13 . As a result of the improved mechanical connection it is better possible to transfer loads from the surface to the underlying roll 11 .
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A calender roll, which was already in use and has a metallic core with engaged textile material sheets, can be worked for a new use. In the surface of the sheets are cut grooves, to which is subsequently applied a layer structure of synthetic resin-impregnated fibrous material forming a certain thickness over each point of the roll. Onto said layer can be applied a functional covering, for example of rubber.
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FIELD
[0001] The present disclosure relates generally to devices and methods useable during well drilling operation. More particularly, the present disclosure pertains to a drilling rig incorporating a dual pipe rotational device apparatus useable for decreasing connection time of pipe segments useable during well drilling or other well operations, and methods of connecting pipe segments useable during well drilling or other operations.
BACKGROUND
[0002] Conventional rotary drilling is performed using a rotary table, which includes a motor mounted on or below the derrick floor for rotating the table, and a Kelly which rationally connects the table to a drill string. Alternative drilling systems have been increasingly used, in which the pipe string drive has been modeled after a drilling unit, including a section of pipe connectable to the upper end of the drill string, and a motor for rotating the upper pipe section to turn the string. In recent years, rotary table drilling units are being replaced with these direct drive drilling units (e.g. top drives, kelly drives).
[0003] A typical direct drive drilling unit includes a motor drive assembly and a pipe handling assembly. The drive assembly includes a motor connected to the drill string by a cylindrical drive sleeve drilling extending downwardly along the centerline of the well from the drill motor. A direct drive unit is normally suspended from a travelling block for vertical travel supported by a derrick assembly. The drilling unit can be mounted on a carriage connected to a pair of vertical guide rails secured to the derrick.
[0004] Drilling is accomplished by the powered rotation of the drill string by the drill motor. The drill string is composed of loose drill string elements with a cutting tool or a bit fixed on the end of a drill string. The drill string elements consist mainly of a piece of pipe, which is provided on either side with fixing elements (e.g. threads) for connecting together adjacent pipe segments. This entire powered drilling assembly can then be moved upwardly and downwardly, with the string, to drive the string directly, without requiring a Kelly and Kelly bushing type connection. The cutting tool and/or drill bit can be threadably connected to the lower end of the drill string which, through the rotational energy supplied by the drill motor, cuts through the earth formation and deepens the well.
[0005] During drilling operations, the drilling tool is guided into and through earth formation by using a drill string. Additional drill string elements (e.g. segments of drill pipe) are repeatedly added to the upper end of the drill string, so that the drilling tool can extend ever further down-well. Assembling such a drill string takes a relatively long time, especially when a large number of pipe sections are assembled in the course of drilling a deep well.
[0006] Additionally, when it is necessary to perform maintenance and/or repairs on a drill string or tools attached thereto, the amount of time required for such an undertaking increases substantially as the depth of a well increases. For example, as the well is drilled, the bit becomes worn and the cutting elements thereof must periodically be replaced. To access a drill bit, the entire drill string must be removed from the well. Other types of damage and/or wear can also require raising the drill string. During the hoisting operation, the drill string is at least partially disassembled (e.g. the drill string is often separated into sections of three joined pipe segments). The time required to raise and disassemble can therefore be substantial.
[0007] As such, when replacement of the bit or other types of repairs, replacement, and/or remedial operations become necessary, at least a portion of the drill string is removed from the well, pulled above the derrick floor, and moved to a pipe storage rack on the derrick or similar location. Subsequent drill string elements are pulled from the well, exposing the next pipe section above the floor, which is similarly removed. This sequence, usually referred to as tripping out, is continued until the necessary portion of the drill string, which can include the entire drill string, is removed from the well. After replacement of the drill bit and/or completion of other remedial operations, the drill string is then reassembled, e.g. tripped in, by reconnecting and lowering all of the pipe sections previously removed.
[0008] As drilling depths and the length of wellbores increases, drilling efficiency must be increased and/or new techniques developed to offset the costly day rates for retaining and operating equipment capable of addressing deep well applications. To prevent a great deal of time from being lost when assembling or dismantling a drill string, a need exists for devices and methods that decrease the time required to disconnect drill string segments and raise a drill string.
[0009] A need also exists for apparatus and methods that can quickly and continuously prepare pipe members for connection, while concurrently performing drilling operations.
[0010] A further need exists for a drilling apparatus having multiple pipe hoisting and driving capabilities available and/or proximate to one another for the purpose of connecting and/or lowering a pipe segment, while a second pipe segment is engaged and prepared for connect.
[0011] A need exists for efficiently communicating drilling fluid into the drill string without requiring deactivation of the drilling fluid pump while successive drilling string segments are being connected.
[0012] Embodiments usable within the scope of the present disclosure meet these needs.
SUMMARY
[0013] Certain embodiments of the invention herein pertain to a rig. In certain embodiments, the rig comprises a plurality of pipe rotational devices; a derrick assembly for supporting the plurality of pipe rotational devices, wherein each of the plurality of pipe rotational devices is slidably disposed within the derrick assembly to move the pipe rotational devices toward a wellbore and away from a wellbore, the wellbore having a wellbore axis; and a plurality of lifting assemblies, wherein the plurality of lifting assemblies are operatively connected to the plurality of pipe rotational devices and each lifting assembly is capable of moving a pipe rotational device of the plurality of pipe rotational devices toward the wellbore and away from the wellbore. In this embodiment, each of the plurality of pipe rotational devices is capable of moving in a perpendicular direction relative to the wellbore. In other embodiments of the aforementioned invention, the derrick assembly is capable of sliding from wellbore to wellbore.
[0014] In still further embodiments pertaining to the rig, each of the plurality of pipe rotational devices are spaced a fixed distance from each other in a plane perpendicular to the wellbore axis. In particular embodiments, there are two pipe rotational devices. Still further, in certain embodiments, each of the plurality of pipe rotational devices move simultaneously in an axis perpendicular to the wellbore axis.
[0015] Other embodiments of the inventions herein pertain to the pipe rotational device, wherein the device is a top drive. In these embodiments, the top drive comprises the following: a housing with a top end and a bottom end; a drive shaft disposed within the housing, the drive shaft capable of rotating in an axis perpendicular to the axis of a wellbore; an elevator assembly positioned within the housing proximal to the drive shaft; a clamp assembly disposed within the housing; and wherein the rotational device is capable of coupling a top end of a pipe segment to the top drive, and wherein the clamp assembly is capable of immobilizing the pipe segment.
[0016] In further embodiments of the top drive, the clamp assembly is capable of moving the top end of the pipe segment toward the drive shaft.
[0017] Other embodiments concern a method of assembling a pipe segment string using some of the aforementioned pipe rotational devices. This method comprises: coupling a first pipe segment having a top and a bottom end with a first pipe rotational device; moving the first pipe segment in a horizontal direction relative to a wellbore axis; engaging the first pipe segment with a pipe string in the wellbore; lowering the first pipe segment into the wellbore; coupling a subsequent pipe segment to a subsequent pipe rotational device; moving the subsequent pipe segment having a top and a bottom end in a horizontal direction relative to the wellbore axis; and engaging the bottom end of the subsequent pipe segment with the top end of the first pipe segment and lowering the subsequent pipe segment into the wellbore.
[0018] In certain embodiments, this method further comprises, wherein coupling a pipe segment to a pipe rotational device comprises: engaging a pipe segment with the elevator assembly; engaging the pipe segment with the clamp assembly; lifting the pipe segment upward to contact a pipe rotational device; and coupling the top end of the pipe segment to the drive shaft.
[0019] Other embodiments of the invention herein pertain to a method of moving a pipe segment using the aforementioned pipe rotational devices. In this embodiment, the method comprises: moving the pipe segment from a first position over the wellbore to a second position wherein the top end of the pipe segment is in contact with the rotational device and the pipe segment is not over the wellbore.
[0020] Further embodiments of the invention concern a method of lifting a pipe segment having a bottom end and a top end, using the aforementioned top drive, wherein the elevator assembly lifts the pipe segment a pre-defined distance to provide a certain clearance between the bottom end of the pipe segment and the wellbore. Additionally, in certain embodiments, the elevator assembly device comprises two rotators in an axis substantially parallel with one another and an outer diameter of the pipe segment is determined by a distance between the two rotators. Still further, in certain embodiments, the pipe segment is clamped by the clamp assembly to prevent rotation and vertical travel of the pipe assembly when the pipe segment is over the wellbore.
[0021] In other embodiments concerning assembling a pipe segment string, additional methods call for the prevention of venting gas from the wellbore into the atmosphere by employing at least one pipe segment with a check valve operatively connected to the pipe segment. In such embodiments, the check valve is opened by engaging the top drive with the pipe segment.
[0022] Other embodiments concerning the assembling of the pipe segment string include communicating a drilling fluid into a fluid passageway of at least one pipe segment lowered into the wellbore. In such embodiments, the drilling fluid is diverted from the fluid passageway during a connection operation wherein one pipe segment is being connected to another pipe segment. Likewise, upon connecting one pipe segment to the other pipe segment, diverting the drilling fluid back to the fluid passageway. In these embodiments, the drilling fluid is diverted to a storage container.
[0023] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order that the manner in which the above-recited and other enhancements and objects of the invention are obtained, we briefly describe a more particular description of the invention briefly rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope, we herein describe the invention with additional specificity and detail through the use of the accompanying drawings in which:
[0025] FIG. 1 depicts an isometric view of an embodiment of a mobile drilling rig useable within the scope of the present disclosure;
[0026] FIG. 2A depicts a side view of the mobile drilling rig shown in FIG. 1 ;
[0027] FIG. 2B depicts a front view of the mobile drilling rig shown in FIG. 1 ;
[0028] FIG. 3A depicts a diagrammatic front view of an embodiment of a top drive assembly and back-up clamp useable within the scope of the present disclosure, positioned above a pipe segment;
[0029] FIG. 3B depicts the top drive assembly and back-up clamp of FIG. 3A with the back-up clamp engaged with the pipe segment;
[0030] FIG. 3C depicts the top drive assembly and back-up clamp of FIG. 3A with both the back-up clamp and top drive engaged with the pipe segment;
[0031] FIG. 3D depicts the top drive assembly and back-up clamp of FIG. 3A with the top drive engaged with the pipe segment;
[0032] FIG. 3E depicts a diagrammatic front view of an embodiment of a second top drive assembly and back-up clamp useable within the scope of the present disclosure, positioned above a pipe segment;
[0033] FIG. 3F depicts the second top drive assembly and back up clamp of FIG. 3E with the back-up clamp engaged with the pipe segment;
[0034] FIG. 3G depicts the top drive assembly and back-up clamp of FIG. 3E with both the back-up clamp and top drive engaged with the pipe segment;
[0035] FIG. 3H depicts the top drive assembly and back-up clamp of FIG. 3E with the top drive engaged with the pipe segment;
[0036] FIG. 4A depicts a diagrammatic front view of an embodiment of a mobile drilling rig usable within the scope of the present disclosure, which includes top drives A and B, in a first position;
[0037] FIG. 4B depicts the mobile drilling rig of FIG. 4A in a second position;
[0038] FIG. 4C depicts the mobile drilling rig of FIG. 4A in a third position;
[0039] FIG. 4D depicts the mobile drilling rig of FIG. 4A in a fourth position;
[0040] FIG. 5 depicts an alternate method of back clamp;
[0041] FIGS. 6A and 6B depict a self-clamping rotary table;
[0042] FIGS. 7A and 7B depict tubular centralizer and pipe clamp;
[0043] FIG. 8 . depicts a pumping manifold; and
[0044] FIG. 9 . depicts a pipe feeder.
LIST OF REFERENCE NUMERALS
[0045] 5 a pipe segment
[0046] 10 drill rig
[0047] 20 base structure
[0048] 30 pipe feeding assembly
[0049] 31 a feeder ramp
[0050] 40 derrick assembly
[0051] 41 upper rail
[0052] 42 lower rail
[0053] 43 stabilizing beams
[0054] 50 raising assembly
[0055] 51 a, 51 b booms
[0056] 52 ram assembly
[0057] 55 a, 55 b hoist assembly
[0058] 60 a, 60 b top drive assemblies
[0059] 61 drive section
[0060] 62 a support section
[0061] 63 a drive shaft
[0062] 64 a collar
[0063] 65 a external springs
[0064] 66 a stop blocks
[0065] 70 a backup clamp
[0066] 71 a, 72 a backup clamps
[0067] 73 a, 74 a clamp links
[0068] 75 a elevator
[0069] 76 a joint elevator
[0070] 77 a elevator links
[0071] 77 a, 77 b pneumatic cylinders
[0072] 78 a, 78 b tapered segments
[0073] 79 a, 79 b radially displaced tapered segments
DETAILED DESCRIPTION
[0074] Introduction
[0075] We show the particulars shown herein by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only. We present these particulars to provide what we believe to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, we make no attempt to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention. We intend that the description should be taken with the drawings. This should make apparent to those skilled in the art how the several forms of the invention are embodied in practice.
[0076] We mean and intend that the following definitions and explanations are controlling in any future construction unless clearly and unambiguously modified in the following examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, we intend that the definition should be taken from Webster's Dictionary 3 rd Edition.
[0077] As used herein, the term “attached,” or any conjugation thereof describes and refers to the at least partial connection of two items.
[0078] As used herein, the term “proximal” refers to a direction toward the center of the valve.
[0079] As used herein, the term “distal” refers to a direction away from the center of the valve.
[0080] As used herein, slidably connected referrers to one component abutting another component wherein one component is capable of moving in a proximal or distal direction relative to the other component.
[0081] As used herein, “pipe” or “pipe segment” refers to an elongated tube with a hollow interior extending from the upper end to the lower end to allow fluid to transfer from the top or upper end to the bottom or lower end. The elongated tube can have any shape such as circular, square, triangular and the like. A pipe is a tubular herein.
[0082] As used herein, a fluid is a gas or liquid capable of flowing through a pipe.
[0083] Moreover, we intend that various directions such as “upper” or “lower”, “bottom”, “top”, “left”, “right” and so forth are made only with respect to explanation in conjunction with the drawings. However, in certain instances the components are oriented differently, such as during transportation, manufacturing and in certain operations and that the components are often able to be oriented differently, for instance, during transportation and manufacturing as well as operation. Because we teach many and varying embodiments within the scope of the concepts, and because many modifications are discussed in the embodiments described herein, we intend that that the details herein should be interpreted as illustrative and non-limiting.
[0084] Additionally, as used herein, a “pipe rotational device” in general refers to any pipe rotational device that can be used in accordance with the disclosure herein for facilitating the installation and retrieval of pipe segments used in downhole operations. Examples of pipe rotational devices which can be used in accordance with the disclosure include top drives, Kelly drives, drilling chuck, power swivel and the like.
[0085] Operation
[0086] Top drive A is inline with the well bore drilling, the next step is making an off-hole connection. In operation, a pipe segment is indexed into a pipe handler on which a top drive is to spud or continue drilling by an automated pipe rack system. The pipe handler then elevates the pipe segment into a position for pickup by top drive B, assuming in this operation that there are two pipe handlers, two top drives, one mast and one wellbore.
[0087] The pipe handler then elevates the pipe segment up into position for pick up by top drive B, which is presently situated in line with the first pipe handler, itself which is off the center of the wellbore at a predetermined height to enable top drive B to come down and latch the pipe segment. The first pipe handler then slides the pipe segment past the end of the handler to the appropriate distance thereby allowing top drive B clearance to come down and latch on with its elevators behind the upset on the pipe.
[0088] The length and position of the pipe is ascertained by a switch at the end of the handler and an encoder on the sliding drive mechanism. This combined with the PLC knowing what size of pipe it is (and thus what thread) (can be determined by weight (load pins or hydraulic pressure) or by manual input of this data) so pin length can be subtracted from total to ensure accuracy. Thus allowing the pipe tally to be automatically tracked and displayed by the PLC real time in the doghouse. This enables the PLC (programmable logic control) to “manage” the pipe tally (actual depth), pipe in hole, pipe coming out of hole, XO (thread change cross overs)'s needed etc. enabling proactive messages to be prompted to the operator (i.e. “XO and TD (top drive thread saver subs/XO from 4½XH extra hole (type of thread for example) to 3½IF internal flush (type of thread for example) needed next connection”) eliminating the human error aspect and increasing efficiency.
[0089] Top drive B's bales are extended and come down onto the pipe accordingly to enable the elevators to be latched and confirmed closed (confirmation either manually or hydraulic/PLC). The angle of the elevators will be manipulated by small rams to hold the proper angle in order to further assist proper latching. Once latching has been accomplished, top drive B begins to hoist to the predetermined height determined by the pipe segment's length considering the height needed to get over the connection at the wellhead. This knowledge of height is accomplished by encoders on the hoisting mechanism that monitor the top drive height constantly. The rams will dump back to tank allowing the elevators to free hang or just add some resistance with an accumulator or orifice to reduce swing when tailing off the end of the first pipe handler of which could be further extended to aid as well, or top drive B will keep the bails extended until fully hoisted and the pipe segment comes off the first pipe handler vertically then allowing the bail cylinders to bring the pipe segment directly below the top drive quill in a controlled manner in order to eliminate swing. This position and distance (in either case) will be determined by collapsed length of the ram and always the same.
[0090] The backup clamp on top drive B now extends down to grab the top of the pipe segment and bring it up into the quill to enable top drive B to screw into it and torque it to said connections' predetermined specified limit (specified since the PLC knows what the thread is from the information gathered prior, again reducing potential human error).
[0091] Alternatively, a pipe arm (or other pipe handling devices known in the industry) could deploy the pipe into alignment with the top drive and then travel vertically to engage the thread or the top drive could travel vertically.
[0092] In order to determine the height needed for thread make up travel, the collapse or extension, depending on the process at the time, distance or position of the floating quill (shock sub, etc.) will be determined by a sensor (encoder, proximity switch etc.) placed accordingly on the floating quill/top drive to inform the PLC where and when to stop contraction (or extension) of the backup clamp. This is combined with the proper automated (pipe supplier recommended) make up procedure i.e.—back one turn (to jump one thread lightly)—rotate clockwise 3 times quickly—slow on make-up turn in rotation in order to establish perfect make up torque. This information will save threads eliminating even more potential human error. It will also alert (off hole) the operator if there are any discrepancies in the makeup procedure, for example if there were too many rotations for the make-up process potentially meaning damaged or incorrect thread mating and now the operator can evaluate before it become a serious issue on or in the hole.
[0093] Pipe torque will be determined by amps (ac) or hydraulic pressure (psi) and controlled by the PLC based on its understanding of the thread in question in order to know the minimum number of turns required to spin in or out, etc.
[0094] Typically, the backup clamp is able to hold torque of the top drive in both directions and elevate the tubular in question. Once the pipe is made up to the top drive, the clamp will lower the pipe to the end of the stroke of the floating quill (shock sub, etc.), determined by the aforementioned linear sensor and released.
[0095] Top drive B now waits “off hole” for top drive A to finish drilling down its pipe.
[0096] The second step is bringing the “off hole” connection over the wellbore to complete final steps of the drilling connection. In this step, top drive B is now slid over the wellbore hole center, and in turn, sliding top drive A off hole and in-line with the second pipe handler, thus allowing it to run through the first step as well with the pipe elevated just above the known stick up height of the pipe top drive B had just landed. This knowledge is from the PLC working with the hoisting system encoder or similar positioning device. This information recorded from when second top drive unscrewed from the prior pipe.
[0097] Next, top drive B is lowered so the first pipe segment's pin end enters the pipe that is set in hyd slips (“chuck slips” or “clamp slip combo” will be used). This application is preferred if there is a potential for a “pipe light” situation due to UBD (under balanced drilling) or “live well” operations. Top drive B now spins the pipe together to the proper torque (determined as above by the PLC) for that connection. The bottom half of the connection is held (if necessary—chuck or clamp slips combined with string weight may be enough to not need iron roughneck for back up) by the iron roughneck and used to make up the connection if the size of the connection calls for more torque than the top drive can achieve.
[0098] If the operation happens to be one of a UBD or “live well” nature and gas is being used to drill with (or well pressure is present and contained at surface), the pipe can be equipped with a “check pipe” system. This will enable the operator to “break out” and continue connections seamlessly without time waiting for bleed down of the previous pipe drilled (due to the expansion of N 2 , for example). In the reverse function (tripping out) it will also allow the operator to be bleeding “just” the pipe being hoisted. By reducing the volume being bled it is able to be done by the time said pipe is finished hoisting thus providing the most time efficient UBD or “live well” connection possible. This bleeding would be directed back to the degassed automatically using the pumping manifold (to be described later) of which will have pressure sensors to confirm pressure is completely bled and safe to continue. The “check pipe” system consists of small one way check valves installed in the box end of the each pipe of which can be opened selectively and bled individually by the top drive when desired, for example on the trip out.
[0099] Once the PLC has determined proper makeup has been achieved, the pumping manifold (automatically via PLC and remote control valves) redirects the drilling medium flow through top drive B and in turn down the pipe, now circulation has been re-established and confirmed. In this case, the fluid could be any medium used for drilling (e.g. N 2 or air.) The PLC will take weight with top drive B based on the last known weight from top drive A and slightly elevate so automatic slips (chuck or clamp) can be released enabling top drive B to then go down to pick up the depth, which was also recorded by data from top drive A, and then reinstate the preset drilling parameters from top drive A to top drive B.
[0100] Top drive B will be able to hoist out of slips and aggressively return to bottom smoothly returning to the drilling parameters just used by the second top drive as the PLC will have recorded and transferred the desired parameters and data to top drive B (such as exact weight, height and pick up/depth). This method is able to reduce human error (spudding bottom, etc.) This method, combined with the ability to recognize and remember toolface (centralizer system incorporated with the chuck slip/clamp slip) can be utilized to aid in tool face tracking in case of slippage beyond just relying on the (top drive) transducers last position. This has the ability to be an extremely efficient tool for directional drillers to pre-program their desired parameters well ahead of time with precision. For example, if the directional drillers needs 15 m slide then 10 m rotation (at specified rate), then 50 m high side reciprocating followed by a survey, the PLC will have the information to accommodate precisely using all the inputs described above in all the previous steps. The end goal would be for one man to be able to directionally drill multiple rigs without even being present as all this data can be shared digitally/wirelessly, etc.
[0101] All limits and settings on any of the rigs' operational parameters will be set by the individual responsible for said parameter, without fear of change by operator or unqualified personnel without permission as these can be locked by individual codes. As a non-limiting example, only the company representative could approve pulling the casing over 300,000 lbs. Thus, in this example, the only way this will be achieved is if the company representative puts his code in and makes it so. All parameter changes and control trends/events will be recorded for assistance in future troubleshooting and root cause analysis.
[0102] The third step in the process is finishing top drive B's currant drilling connection and preparing for top drive A to drill its next simultaneously prepared connection as in the previous steps. In this operation, using an upstream pumping manifold, the flow will have been previously redirected to a route maintaining close to its drilling circulation pressure saw on the second top drive just before it had broken out of the previous pipe. A Kelly hose line will have been automatically drained, bled or even had suction pressure applied to it to limit drilling fluid escaping from top drive while unconnected. This enables the rig to make a connection without ramping and shutting down the pump, or multiple pumps, saving this time and the time it takes to put the pump, or pumps, back online at the desired parameters. It also reduces any potential adverse pump loading (stalling/synchronizing issues) when considering multiple pumps as the pumps will always be loaded in unison or the established load maintained. This redirected “route” can be wherever makes sense for the type of operation, e.g. in an overbalanced situation it could be put back to the shaker or down the flowline. In a managed pressure or underbalanced situation, the flow can be directed across the drilling cross (BOP well annulus) (or other path ending up at the chokes) and down through the chokes. This will help maintain a constant bottom hole pressure and limit the choke adjustments during connections. This aspect combined with the greatly reduced time for the connection greatly helps keep the BHP constant and the choke adjustments to a minimum.
[0103] In a MPD (managed pressure drilling) or UBD application, the chokes could be automated and relaying the information to the rigs PLC in order to regulate BHP (bottom hole pressure) during the connection (and while drilling for that matter) e.g. PLC knowing during an MPD connection when flow is diverted back through chokes directly that back pressure at that flow should be increased by equivalent circulating density. The PLC will already be equipped with most the information needed to maintain BHP at a set point by knowing the depth, drilling fluid weight, pump rate and pressure using transducers at the chokes. With this information we can also set a mean line on a graph for the PLC to adjust the choke setting to the operator's desired parameter i.e. to maintain pressure +− a set point or formation pressure as well as the potential incorporation of precise flow rate monitoring in and out of well. This can be described on a line graph showing formation pressure and volume differentials of which would give the operator early potential kick detection when drilling overbalanced or MPD.
EXAMPLES
[0104] The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
[0105] Referring now to FIG. 1 , reference numeral ( 10 ) denotes a mobile drilling rig, hereafter referred to as a drill rig. The drill rig ( 10 ) comprises a base structure ( 20 ), a pipe feeding assembly ( 30 ), a derrick assembly ( 40 ), a raising assembly ( 50 ) and two top drive assemblies ( 60 a, 60 b ).
[0106] The base structure ( 20 ) is shown having a generally flat rectangular surface, adapted to support the pipe feeding assembly ( 30 ) and the derrick assembly ( 40 ), which are shown integrated thereon. The base structure ( 20 ) is also shown with a plurality of wheeled axels ( 25 ) which can be used for mobility and ( 25 ) which can include a corresponding suspension system (not shown) and similar components to allow the drill rig ( 10 ) to be pulled by a standard truck (not shown) or similar vehicle, in the manner of a mobile trailer. A stabilizer, or multiple stabilizers, in certain applications are included in the base structure ( 20 ) for stabilizing the drill rig ( 10 ) during operations. For example, the base structure ( 20 ) could incorporate a plurality of support arms (not shown) that can be movable to contact the ground to provide leverage and/or stability to the drill rig ( 10 ).
[0107] The base structure ( 20 ) supports the derrick assembly ( 40 ), which provides structural support for the lifting assembly ( 50 ) and a pathway along which the lifting assembly ( 50 ) can move during drilling and/or lifting/lowering operations. As depicted, the lifting assembly ( 50 ) is not fixedly attached to the base ( 20 ). In certain applications, this allows for a variety of structural support mechanisms. The derrick assembly ( 40 ), for example, is able to provide sufficient structural support, as the lifting assembly ( 50 ) is subjected to significant compressive and bending loads during drilling operations when the booms ( 51 a, 51 b ) and the ram assembly ( 52 ) move vertically and horizontally, respectively. In an embodiment, the derrick assembly ( 40 ) can be constructed as a lattice structure and can comprise a generally two dimensional or a three dimensional configuration. The depicted derrick assembly ( 40 ) is shown having a width approximately equal to the width of the base ( 20 ), and a height that extends above the booms ( 51 a, 51 b ) of the lifting assembly ( 50 ). The derrick assembly ( 40 ) is also depicted with stabilizing beams, ( 43 ) shown extending toward the center of the base assembly ( 20 ) which provides the derrick assembly ( 40 ) with additional structural strength and stability.
[0108] Derrick assemblies, in general, are known in the drilling industry, and are well understood by those of ordinary skill in the art. Therefore, it should be understood that the derrick assembly ( 40 ) can be configured in any manner known in the industry sufficient to provide support for the lifting assembly ( 50 ). For example, a three dimensional derrick assembly (not shown) in certain applications can be used, having a shape of a narrow pyramid with a truncated top, with the guide rails attached along the side thereof. A three dimensional guide frame can provide additional strength and stability in supporting the lifting assembly ( 50 ), and in certain applications, this configuration is used, for example, in conjunction with larger drill rigs, which are designed to handle longer or wider diameter pipe segments, which are typically much heavier.
[0109] The guide mechanism for the lifting assembly ( 50 ) is shown including a pair of rails ( 41 , 42 ) attached to the base assembly ( 20 ) and the derrick assembly ( 40 ), extending horizontally thereon. The lower rail ( 42 ) is shown attached to the base ( 20 ), while the upper rail ( 41 ) is shown attached to the derrick assembly ( 41 ). The ram assembly ( 52 ) can be movably connected to the rails, such as through use of two sets of rollers (not shown).
[0110] In the aforementioned embodiment of the ram assembly, wherein the ram assembly is movably connected to the rails, the rail and roller assemblies can be of any known construction sufficient to withstand the compressive and lateral forces applied by the lifting assembly as it supports the weight of the top drives ( 60 a, 60 b ) as well as attached pipe segments ( 5 a, 5 b, shown in FIGS. 4A through 4D ), which are suspended above the wellbore. Lower rollers (not shown) can be attached to the bottom surface of the ram assembly ( 52 ) to engage the lower rail ( 42 ), while upper rollers (not shown) can be attached to the upper portion of the ram assembly ( 52 ) and engage the corresponding upper rail ( 41 ). It should be understood that the specific number and type of rail and roller combinations is not limited to the described embodiment, and in certain applications will include any number and type of roller assemblies, or any other movable forms of engagement usable to allow horizontal motion of the lifting assembly ( 50 ) while providing sufficient structural strength to support the weight of the ram assembly ( 52 ), the booms ( 51 a, 51 b ), and any other tools and components attached thereto during drilling operations.
[0111] The derrick assembly ( 40 ) can provide support for the lifting assembly ( 50 ), which can include the ram assembly ( 52 ) having first and second booms ( 51 a, 51 b ) extending therefrom, the ram assembly ( 52 ) being adapted to move horizontally along the guide rails ( 41 , 42 ). In certain applications, the ram assembly ( 52 ) can include an actuator to actuate the first and second booms ( 51 a, 51 b ) in the vertical and horizontal directions. Such an actuator can include hydraulic cylinders (not shown) connected to the lower portion of the booms ( 51 a, 51 b ), other types of fluid cylinders, mechanical actuators, or combination thereof. Upon actuation of a hydraulic cylinder or similar mechanism, the respective boom ( 51 a, 51 b ) can be forced out of the ram assembly ( 52 ) e.g. in the upward direction, lifting a top drive ( 60 a, 60 b ). A geared mechanism in certain applications or configurations use used to provide vertical motion of the booms ( 51 a, 51 b ) and/or the horizontal motion of the lifting assembly ( 50 ). For example, the lifting assembly ( 50 ) in certain applications comprises an internal rack and pinion mechanism (not shown), whereby a pinion, which, depending on the size of the booms and the application, can be powered by an electrical motor or other motive and/or power source, engages teeth along the length of the booms ( 51 a, 51 b ) causing movement in the vertical direction. As described above, the ram assembly ( 52 ) and the booms ( 51 a, 51 b ) can also move horizontally (i.e. perpendicular to the well bore). Similar methods for actuating the booms ( 51 a, 51 b ) and/or the ram assembly ( 52 ) to move in a horizontal direction are also used, such as one or more hydraulic cylinders (not shown) or similar elements attached to the base assembly ( 20 ) or the derrick assembly ( 40 ), with a piston rod attached to the ram assembly ( 52 ). Upon actuating the hydraulic cylinder the ram assembly ( 52 ) can be moved horizontally along guide rails ( 41 , 42 ). Alternatively or additively, actuation of the ram assembly ( 52 ) in the horizontal direction can include a geared mechanism (not shown). For example, the ram assembly ( 52 ) can comprise a rack and pinion assembly (not shown), whereby a pinion, which can be powered by an electrical motor (not shown) or similar motive and/or power source, engages with and actuates a rack assembly (not shown) associated with the ram assembly ( 52 ), causing it to move horizontally along the guide rails ( 41 , 42 ).
[0112] As further depicted in FIG. 1 , each boom ( 51 a, 51 b ) supports a cable winch ( 56 a, 56 b ), which is a part of a hoist assembly ( 55 a, 55 b ), usable for moving an associated top drive ( 60 a , 60 b ) in the vertical direction. Each hoist assembly ( 55 a, 55 b ), in combination with a boom ( 51 a , 51 b ), can function in a manner similar to a crane, by extending and retracting a cable or wire to move the associated top drive ( 60 a, 60 b ) vertically. For example, the vertical position of each top drive ( 60 a, 60 b ) can be controlled by winding and unwinding cable drum (not shown) or a spool, which can be rotated by a motor (not shown) to control the height of the top drive ( 60 a , 60 b ) relative to the opening ( 21 ). Any type of motor or other motive source (e.g. a hydraulically or electrically powered source, as well as any other known method for extending or retracting cable of sufficient force in this application, and resulting in vertical movement of the drive assembly, can be used. Likewise, moving the drive assembly in the vertical direction can be accomplished by any mechanism capable of providing sufficient force. As one example, the mechanism can include an internal rack and pinion mechanism whereby a pinion, which, depending on the size and mass of the drive assembly and its application, can be powered by an electrical motor or other motive and/or power source, engages teeth along the length of the mast booms (not shown) causing movement in the vertical direction. As another example, the lifting assembly can incorporate a traveling block with a series of sheaves and cables powered by a winch. In this example, the winch can be manually operated or powered by a motor. The lifting assembly can include a hydraulic ram connected to the top drive.
[0113] Top drive assemblies usable with the embodiments depicted in FIGS. 1 , 2 A, and 2 B, are shown in FIGS. 3A-3D . FIG. 3A depicts a top drive assembly ( 60 a ); having a drive section ( 61 a ) an elevator assembly ( 75 a comprising the elevator ( 76 a ) and the bail ( 77 a ) and a backup clamp ( 70 a ). Typically, elevator ( 76 a ) and the bail 77 a swing out together to engage a tubular from the pipe handler. The drive section ( 61 a ) can include a motor (now shown), a transmission (not shown), a support section ( 62 a ), and an output shaft ( 63 A). The depicted section ( 62 a ) serves as the central body of the top drive, having the other components attached thereto. The drive shaft ( 63 a ) is shown positioned through the center of the support section ( 62 A), which during operation, can be used to threadably engage a pipe segment ( 5 a ) and drive a drill bit (not shown), located at the bottom end of a pipe string (not shown). In the depicted embodiment, the drive shaft ( 63 a ) maintains its position and the capacity to rotate within the support section ( 62 a ) via a collar ( 64 a ) located through the center of the support section ( 62 a ), positioned concentrically about the drive shaft ( 63 a ). The drive shaft ( 63 a ) can be retained within the collar ( 64 a ), while having the ability to rotate therein as the drive shaft is rotated by the motor/transmission systems. The drive shaft ( 63 a ) can transmits torque from the motor to a pipe segment ( 5 a ) connected thereto, thereby rotating the pipe string during drilling operations. The collar ( 64 a ) can be centralized (e.g., in a vertical position) through the support section ( 62 a ) by external springs ( 65 a ), located on either or both sides thereof, which can bias the collar ( 64 a ) to a preselected location relative to the base, the support section ( 62 a ) or another portion of the assembly. The springs ( 65 a ) can allow the drive shaft ( 63 a ) limited vertical movement in response to vertical forces applied thereto, as further explained below. The shaft collar ( 64 a ), also has stop blocks ( 66 a ) in certain applications for setting discrete limits on vertical motion of the drive shaft ( 63 a ) relative to the support section ( 62 a ). Other methods for providing the vertical travel in the drive shaft include, but are not limited to, compressive hydraulic cylinders and free floating sleeves.
[0114] In certain applications, an additional traveling block (not shown) is incorporated into the hoist assembly, and attached to the top drive ( 60 a ) with a lifting ring (not shown). It should be understood that while FIGS. 3A-3D depict one embodiment of a top drive assembly and the drive section ( 61 a ), any configuration having the capacity to drive the selected pipe segments is contemplated.
[0115] The pipe handling components of the top drive assembly ( 60 a ), shown extending from the support section ( 62 a ), can include an elevator assembly ( 75 a ) and a backup clamp assembly ( 70 a ). FIG. 3A depicts an embodiment in which the elevator assembly ( 75 a ) comprises a single joint elevator ( 76 a ) connected to the base via two elevator links ( 77 a ) (e.g., bail arms). A link tilt mechanism (not shown) can also be connected between the support section ( 62 a ) and the elevator links ( 77 a ), allowing the rotation of the elevator assembly ( 75 a ) during operation, enabling the single joint elevator ( 75 a ) to extend a pipe segment ( 5 a ) located on the feeder ramp ( 31 b ), as explained in detail below.
[0116] While the illustrations herein refer to an elevator assembly, other pipe lifting mechanisms such as pipe arms or dual mouse hole connections with a Kelly drive set up can be used.
[0117] As described above, FIG. 3A depicts a back-up clamp assembly ( 70 a ) associated with the top drive assembly. The depicted back-up clamp assembly ( 70 a ) is shown having two portions and/or halves, e.g. two back-up clamps ( 71 a, 72 a ) and two clamp links ( 73 a, 74 a ) that each engage a respective back-up clamp ( 71 a, 72 a ) to the support section ( 62 a ). The links ( 73 a , 74 a ) have the ability to extend and retract vertically, e.g. to move the clamps ( 71 a, 72 a ) about the box end of the pipe segment ( 5 a ). As such, the back-up clamps ( 71 a, 72 a ) are designed to grip and hold a pipe segment, preventing the pipe segment from moving vertically or rotating. Each back-up clamp ( 71 a, 72 a ) can have a semicircular shape, complementary to the outside diameter of the pipe segment ( 5 a ), and an inside surface having teeth, slip inserts, or other gripping elements (not shown) designed to grip against the outside surface of the pipe segment ( 5 a ) and prevent relative movement between the pipe segment and the clamps. A hydraulic or pneumatic cylinder (not shown) connected between the base and the clamp links ( 73 a, 74 a ), in certain applications, is used to move the back-up clamp assembly ( 70 a ) between the open and closed positions, as depicted in FIGS. 3C and 3D respectively. To enable vertical movement of the back-up clamps ( 71 a, 72 a ), each clamp link ( 73 a, 74 a ) can include a hydraulic or pneumatic cylinder (not shown) and the like. For example, the back-up clamps ( 71 a, 72 a ) can be attached to the rod end of each cylinder to enable vertical extension and retraction thereof.
[0118] In an alternate embodiment, a remotely actuated spider assembly located below the drive shaft ( 63 a ) is able to grasp a pipe segment ( 5 a ). In the open position, the spider can provide sufficient space for a pipe segment ( 5 a ) to pass through, and when closed, the spider can firmly grasp the pipe segment ( 5 a ), preventing any vertical or rotational motion. Similar to the back-up clamps ( 71 a, 72 a ), the spider assembly is supported below the drive shaft ( 63 a ) by a plurality of hydraulic or pneumatic cylinders, thus providing the spider with the ability to move vertically. FIG. 5 shows a plurality of hydraulic or pneumatic cylinders ( 77 a, 77 b ) radially displaced travel horizontally moving tapered segments ( 78 a, 78 b ) towards the center of the radial arrangement. The tapered segments act against a plurality of radially displaced tapered segments ( 79 a, 79 b ) concentrically with the first set of segments to clamp a tubular (not shown) thru a wedging action
[0119] The benefits of the embodiments described herein become further apparent during operations, for example, drilling, pipe tripping, or casing tripping. For example, embodiments depicted in FIGS. 1 , 2 A, and 2 B can enable simultaneous down-well operations while connecting and disconnecting pipe segments, allowing a more efficient utilization of time.
[0120] As shown in the embodiment depicted in FIGS. 1 , 2 A, and 2 B, the drill rig ( 10 ) is designed to include two top drives ( 60 a, 60 b ), which can work simultaneously, enabling the first top drive ( 60 a ) to perform a first function, such as drilling, while the second top- drive ( 60 b ) performs a second function, such as preparing a subsequent pipe segment for connection to pipe string. Furthermore, as depicted in FIG. 5 , additional time can be saved through use of a manifold adapted to allow fluid flow to bypass the mud pump, rather than using the conventional practice of shutting down the mud pump during connection and/or disconnection of a pipe segment. This ability results in improved well control, near consistent circulation, reduced circulation down time and the risks associated with circulation down time (i.e. stuck pipe, hole cleaning and formation stability).
[0121] In an embodiment, operations of a drill rig such as the embodiment depicted in FIG. 1 can be largely automated, reducing the amount of time between each step of the drilling, raising, lowering, connection, and/or disconnection operations. A system of sensors, such as timers and limit switches, which can be connected to a computer or an electronic controller, can be used to automatically detect the commencement and end of each operational stem and automatically initiate the next step, reducing wait time between steps, and also reducing the number of personnel required to operate the drill rig, resulting in cost savings and in improved safety by reducing the number of individuals on a rig floor.
[0122] The order of steps performed using embodiments described herein can be varied, and can allow performance of said down-well operations to be streamlined, eliminating delays normally present during pipe insertion and extraction operations, such as enabling performance of critical steps simultaneously and reducing or eliminating the delay between steps on the specific down-well operations to be performed. Shorter wait times also result in an improved ability to maintain bottom hole pressure, e.g. for managed pressure drilling and under balanced drilling operations.
[0123] Referring to FIGS. 4A-4D , an embodiment of the first and second top drives ( 60 a , 60 b ) is depicted, showing steps comprising the operation of the drill rig ( 10 ). For clarity purposes, the remaining components of the drill rig ( 10 ) are not shown.
[0124] FIG. 4A depicts the first top drive ( 60 a ) located at a first position (e.g. an elevated position) with a first pipe segment ( 5 a ) threadably connected with the first drive shaft ( 63 a ) such that the pipe segment hangs over the base opening ( 21 ). The second top drive ( 60 b ) is shown in a second position (e.g. a lowered position), with a second pipe segment ( 5 b ) coupled to the elevator ( 76 b ) associated therewith. When a drill rig is in the position shown in FIG. 4A , drilling operations are able to commence using the first top drive ( 60 a ) As the first top drive ( 60 a ) rotates the pipe segment ( 5 a ) and the drill bit ( 6 ), the first top drive ( 60 a ) can be lowered into the base opening ( 21 ) and into the wellbore, as a drilling mud pump (not shown) flows the drilling mud through the fluid passage (not shown) of the first drive shaft ( 63 a ), through the pipe segment ( 5 a ).
[0125] The second pipe segment ( 5 b ) can be coupled to the elevator by a pipe feeding assembly ( 30 b ), as described above, which can handle and strategically place pipe segments. Specifically, pipe segments can be contained in a storage rack (not shown) located adjacent to the rig ( 10 ). Individual pipe segments can then be presented adjacent to the top drive ( 60 b ), where the bale assembly ( 75 b ) can swing out and/or extend toward the pipe segment ( 5 b ) to couple an elevator ( 76 b ) with the box end of the pipe segment ( 5 b ). Referring to FIG. 9 , a position sensor ( 95 ) on feeder ramp ( 31 b ) contacts box end of pipe segment ( 5 b ), pipe positioner ( 9 b ) contacts position sensor ( 95 ) as the pipe ( 5 b ) travels, and the pipe length is determined. A specific embodiment of the feeder ramp ( 31 b ) is shown in FIGS. 1 , 2 A and 2 b, feeder ramps are generally known in the drilling industry, and any type of feeder ramp or other pipe handling system can be used without departing from the scope of the present disclosure.
[0126] Returning to the FIGS. 3A-3D , which depict a close-up view of the top drive ( 60 a ) in the course of drilling operations, it should be noted that the two top drives ( 60 a, 60 b ) shown in FIGS. 4A-4D can be of identical or similar construction as the depicted first top drive ( 60 a ). Therefore, the operations undertaken by the second top drive ( 60 b ) depicted in FIGS. 4A-4D can be described with reference to FIGS. 3A-3D .
[0127] Specifically, as the top drive ( 60 b ) is raised to an elevated position (as shown in FIG. 4B ) the pipe segment ( 5 b ) becomes vertically aligned with the drive shaft ( 63 b ), located above, as depicted in FIG. 3F (which shows pipe segment ( 5 b ) aligned beneath drive shaft ( 63 b )). The back-up clamps of the top drive ( 60 b ) can then be lowered and closed about the top end of the pipe segment ( 5 b ) as depicted in FIG. 3F (which shows the back-up clamps ( 71 b, 72 b ) engaged with pipe segment ( 5 b ), preventing any further relative motion there between. After the pipe segment ( 5 b ) is engaged, the back-up clamps of the top drive ( 60 b ) can be raised upward, lifting the pipe segment ( 5 b ) from the elevator to abut the threaded end of the drive shaft ( 63 b ), as illustrated in FIG. 3G (which shows the backup clamps ( 71 b, 72 b ) raised such that the pipe segment ( 5 b ) abuts the drive shaft ( 63 b )). FIG. 3G shows a position sensor ( 67 b ), which can detect contact between the pipe segment ( 5 b ) and the drive shaft ( 63 b ), such that upward movement of the back-up clamps ( 71 b, 72 b ) can be ceased responsive to detection of this contact. Identical or similar components can be used in conjunction with the top drive ( 60 a ). The drive motor (not shown) can then be actuated, causing the male threads of the drive shaft ( 63 b ) to engage the female threads of the pipe segment ( 5 b ). Once the drive shaft ( 63 b ) is engaged with the pipe segment ( 5 b ), the back-up clamps of the top drive ( 60 b ) can be disengaged from the pipe segment ( 5 b ) as illustrated in FIG. 3H (which depicts pipe segment ( 5 b ) threaded to drive shaft ( 63 b ), while back-up clamps ( 71 b, 72 b ) are disengaged from the pipe segment). While the operations described above with reference to the top drive ( 60 b ) are performed, the top drive ( 60 a ) can be used to continue drilling and/or lowering operations, moving vertically downward until it reaches its lowered position, as shown in FIG. 4B .
[0128] FIG. 4B depicts the top drive ( 60 b ) in an elevated position, having a pipe segment ( 5 b ) engaged with the drive shaft ( 63 b ) thereof, and the top drive ( 60 a ) in a lowered position, having a pipe segment ( 5 a ) engaged therewith and mostly inserted through the base opening ( 21 ) and into the wellbore. At this stage of operations the flow of drilling mud (not shown) can be diverted by a manifold shown in FIG. 8 to a tank (not shown) or alternate path by opening valve ( 87 ) and closing valve ( 85 ) to top drive ( 60 a ), bleed off valve ( 88 a ) is opened to drain and/or suction the drilling mud from the drive shaft ( 63 a ) to prevent the drilling mud from draining on the platform ( 20 ). Once slips ( 22 ) are engaged with the pipe segment ( 5 a ), the drive motor can turn the drive shaft ( 63 a ) to disengage the threads of the drive shaft ( 63 a ) from those of the pipe segment ( 5 a ). The raising assembly ( 50 ) can then move along the guide rails ( 41 ), shifting the horizontal position of the top drives ( 60 a, 60 b ), such that the top drive ( 60 b ) and engaged pipe segment ( 5 b ) are aligned over the wellbore, while the top drive ( 60 a ) is positioned suitably for engagement with a subsequent pipe segment ( 5 c ).
[0129] As such, when the depicted system is in the position shown in FIG. 4C , segment ( 5 b ) contacts with the female threads of the first pipe segment ( 5 a ) located within the wellbore. Once contact is made, the drive motor (not shown) of the top drive ( 60 b ) engages the second drive shaft ( 63 b ) to rotate the suspended pipe segment ( 5 b ), connecting it with the first pipe segment ( 5 a ) located within the wellbore. Once the threads of the pipe segments ( 5 a, 5 b ) are fully engaged, the flow of the drilling mud (not shown) can be directed from the mud pump (not shown) to the top drive ( 60 b ) and the slips are removed, as depicted in FIG. 4C , whereby the drilling process can continue by rotating and lowering the pipe string in the down-well direction.
[0130] While the pipe segments ( 5 a, 5 b ) are being connected, and during the drilling operations that follow, the top drive ( 60 a ) can be engaged with a subsequent pipe segment ( 5 c ), in the manner described above with reference to FIGS. 3A-3D . For example, as depicted in FIG. 4C , the top drive ( 60 a ), in a lowered position, where the subsequent pipe segment ( 5 c ) can be coupled to the elevator ( 76 a ) associated with the top drive ( 60 a ) through the process described above or any other suitable process known in the art.
[0131] Once the subsequent pipe segment ( 5 c ) is coupled to the first elevator ( 76 a ), the top drive ( 60 a ) can be moved upward, lifting the pipe segment ( 5 c ) from the feeder ramp ( 31 a ) until it is in vertical alignment below the drive shaft ( 63 a ). Pipe segment ( 5 ) length is measured as described above and referencing FIG. 9 . As described above, when the top drive ( 60 a ) reaches an elevated position with the pipe segment ( 5 c ) aligned with the drive shaft ( 63 a ), as depicted in FIG. 3B , the back-up clamps ( 71 a, 72 a ) can be engaged with the top end of the pipe segment ( 5 c ), preventing any further relative motion there between. Once the pipe segment is engaged, the back-up clamps can move ( 71 a, 72 a ) vertically, lifting the pipe segment from the elevator ( 76 a ) into contact with the threaded end of the drive shaft ( 63 a ), as depicted in FIG. 3C . A position sensor ( 67 a ) can detect contact between the pipe segment ( 5 c ) and the drive shaft ( 63 a ), and the backup assembly ( 70 a ) can cease movement of the clamps ( 71 a, 72 a ) responsive to detection of this contact. The drive motor (not shown) of the top drive ( 60 a ) can then be activated, causing the male threads of the drive shaft ( 63 a ) to engage the female threads of the pipe segment ( 5 c ). Sensors (not shown) detect the number of revelations of the drive shaft and torque thereof and cease rotation of the driveshaft once certain values are met indicating the drive shaft ( 63 a ) is fully engaged with pipe segment ( 5 c ), the back-up clamps ( 71 a, 72 a ) travel vertically down position sensor ( 76 a ) can detect that weight of the pipe segment ( 5 c ) is no longer being supported by back-up clamps ( 71 a, 72 a ), back-up clamps ( 71 a , 72 a ) can be disengaged from the pipe segment ( 5 c ).
[0132] While the subsequent next pipe segment ( 5 c ) is engaged with the top drive ( 60 a ), the top drive ( 60 b ) can be used to continue drilling and/or lowering operations, descending to a lowered position and inserting the pipe segment ( 5 b ) into the wellbore, as depicted in FIG. 4D . At this stage of operations, the flow of the drilling mud (not shown) are able to be diverted to the tank (not shown) and the drive shaft ( 63 b ) disengaged from the pipe segment ( 5 b ), back-up clamps ( 71 b, 72 b ) are set about the pipe segment ( 5 b ), the drive shaft ( 63 b ) can be turned in the opposite direction, disengaging the top drive ( 60 b ) from the pipe segment ( 5 b ). Once the pipe segment ( 5 b ) is disconnected from the drive shaft ( 63 b ) and the subsequent pipe segment ( 5 c ) is engaged with the drive shaft ( 63 a ) located in the elevated position, the top drives ( 60 a, 60 b ) can shift laterally, as described previously, aligning the top drive ( 60 a ) and associated pipe segment ( 5 b ) over the base opening ( 21 ), and moving the top drive ( 60 b ) to a position suitable for engagement with the next pipe segment, as depicted in FIG. 4A . This process can be repeated to engage and lower any number of pipe segments into a wellbore, and can be performed in reverse to remove any number of pipe segments from a wellbore. Further, while the process above is described with reference to drill pipe and drilling operations, it should be understood that embodiments described herein can also be applicable with casing, production tubing, and other types of tubulars.
[0133] FIG. 6A depicts an alternate method of clamping tubulars in the base opening ( 21 ). A plurality of radially displaced wedged segments ( 83 ) is concentric with circular housing ( 80 ) and threadably engages the drive motor ( 82 ) the drive ring ( 81 ) travels wedged segments vertically downwards to clamp a tubular (not shown) concentric with the base opening ( 21 ). Reversing the rotation of the drive motor ( 82 ) travels the wedged segments ( 83 ) vertical direction upwards unclamping the tubular. Dowels ( 84 ) engage the wedged segments ( 83 ) with the circular housing ( 80 ) to retain the wedged segments ( 83 ), a bushing ( 84 ) is inserted in the wedged segments to adapt the segments to different diameters of tubulars.
[0134] FIG. 7A . depicts an alternate embodiment of a tubular centralizer and clamp. A pipe segment ( 5 a ) is grasped by a remotely actuated spider ( 89 ) assembly located below the base opening ( 21 ). In the open position, the spider provides sufficient space for a pipe segment ( 5 a ) to pass through. FIG. 9 a shows a plurality of hydraulic or pneumatic cylinders ( 90 ) radially displaced, thus providing the rollers ( 91 ) the ability to travel horizontally and when closed, the rollers ( 91 ) firmly grasp the pipe segment ( 5 a ), centralizing the pipe segment ( 5 a ) to the base opening ( 21 ) and thus the well bore. The spider assembly optionally includes a series of linkages (not shown) to cause the rollers ( 91 ) to engage the pipe segment ( 5 a ) simultaneously.
[0135] FIG. 7A . further depicts a plurality of hydraulic or pneumatic cylinders ( 93 ) radially displaced around the base opening center ( 21 ), thus providing clamps ( 94 ) with the ability to move horizontally to engage the pipe segment ( 5 a ), preventing any vertical or rotational motion.
[0136] From the foregoing description, one of ordinary skill in the art can easily ascertain the essential characteristics of this disclosure, and without departing from the spirit and scope thereof, can make various changes and modifications to adapt the disclosure to various usages and conditions. For example, we do not mean for references such as above, below, left, right, and the like to be limiting but rather as a guide for orientation of the referenced element to another element. A person of skill in the art should understand that certain of the above-described structures, functions, and operations of the above-described embodiments are not necessary to practice the present disclosure and are included in the description simply for completeness of an exemplary embodiment or embodiments. In addition, a person of skill in the art should understand that specific structures, functions, and operations set forth in the above-described referenced patents and publications can be practiced in conjunction with the present disclosure, but they are not essential to its practice.
[0137] The invention can be embodied in other specific forms without departing from its spirit or essential characteristics. A person of skill in the art should consider the described embodiments in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. A person of skill in the art should embrace, within their scope, all changes to the claims which come within the meaning and range of equivalency of the claims. Further, we hereby incorporate by reference, as if presented in their entirety, all published documents, patents, and applications mentioned herein.
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The present disclosure relates generally to devices and methods useable during well drilling operation. More particularly, the present disclosure pertains to a drilling rig incorporating a dual top drive apparatus useable for decreasing connection time of pipe segments useable during well drilling or other well operations, and methods of connecting pipe segments useable during well drilling or other operations.
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[0001] This application is a continuation-in-part of U.S. application Ser. No. 13/456,353 filed Apr. 26, 2012.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to phacoemulsification surgery and more particularly to an infusion sleeve that reduces the likelihood of injury to delicate eye structures during surgery.
[0003] The human eye functions to provide vision by transmitting light through a clear outer portion called the cornea, and focusing the image by way of a crystalline lens onto a retina. The quality of the focused image depends on many factors including the size and shape of the eye, and the transparency of the cornea and the lens. When age or disease causes the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. An accepted treatment for this condition is surgical removal of the lens and replacement of the lens function by an artificial intraocular lens (IOL).
[0004] In the United States, the majority of cataractous lenses are removed by a surgical technique called phacoemulsification. A typical surgical hand piece suitable for phacoemulsification procedures consists of an ultrasonically driven phacoemulsification hand piece, an attached hollow cutting needle surrounded by an irrigation sleeve, and an electronic control console. The hand piece assembly is attached to the control console by an electric cable and flexible tubing. Through the electric cable, the console varies the power level transmitted by the hand piece to the attached cutting needle. The flexible tubing supplies irrigation fluid to the surgical site and draws aspiration fluid from the eye through the hand piece assembly.
[0005] The operative part in a typical hand piece is a centrally located, hollow resonating bar or horn directly attached to a set of piezoelectric crystals. The crystals supply the required ultrasonic vibration needed to drive both the horn and the attached cutting needle during phacoemulsification, and are controlled by the console. The crystal/horn assembly is suspended within the hollow body or shell of the hand piece by flexible mountings. The hand piece body terminates in a reduced diameter portion or nosecone at the body's distal end. Typically, the nosecone is externally threaded to accept the hollow irrigation sleeve, which surrounds most of the length of the cutting needle. Likewise, the horn bore is internally threaded at its distal end to receive the external threads of the cutting tip. The irrigation sleeve also has an internally threaded bore that is screwed onto the external threads of the nosecone. The cutting needle is adjusted so that its tip projects only a predetermined amount past the open end of the irrigation sleeve.
[0006] During the phacoemulsification procedure, the tip of the cutting needle and the end of the irrigation sleeve are inserted into the anterior capsule of the eye through a small incision in the outer tissue of the eye. The surgeon brings the tip of the cutting needle into contact with the lens of the eye, so that the vibrating tip fragments the lens. The resulting fragments are aspirated out of the eye through the interior bore of the cutting needle, along with irrigation solution provided to the eye during the procedure, and into a waste reservoir.
[0007] Throughout the procedure, irrigating fluid is introduced into the eye, passing between the irrigation sleeve and the cutting needle and exiting into the eye at the tip of the irrigation sleeve and/or from one or more ports, or openings, in the irrigation sleeve near its end. The irrigating fluid protects the eye tissues from the heat generated by the vibrating of the ultrasonic cutting needle. Furthermore, the irrigating fluid suspends the fragments of the emulsified lens for aspiration from the eye.
[0008] Power is applied to the hand piece to vibrate the cutting needle. In general, the amplitude of needle movement (or vibration) is proportional to the power applied. In conventional phacoemulsification systems, the needle vibrates back and forth producing a longitudinal needle stroke. In improved systems, the needle may be caused to vibrate in a twisting or torsional motion. Regardless of the type of vibration, the magnitude of vibration (or amplitude of needle stroke) varies with applied power.
[0009] One complication that may arise during the procedure is damage to eye structures such as the iris. As the needle vibrates torsionally, it imparts circumferential motion to the irrigation sleeve. The circumferential vibrations transmitted by the sleeve to an eye structure, such as the iris, may damage it. An improved irrigation sleeve may be used to decrease the physical force transmitted by circumferential motion of the sleeve to eye structures.
SUMMARY OF THE INVENTION
[0010] In one embodiment consistent with the principles of the present invention, the present invention is an infusion sleeve has a flexible tube enclosing a lumen. The tube has a plurality of wall segments, each wall segment located between the lumen and an exterior surface of the tube and extending parallel to a central axis of the tube. The plurality of wall segments includes at least two thick wall segments and at least two thin wall segments alternately arranged such that each thick wall segment is adjacent to two thin wall segments, and each thin wall segment is adjacent to two thick wall segments.
[0011] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. The following description, as well as the practice of the invention, set forth and suggest additional advantages and purposes of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
[0013] FIG. 1 is a diagram of the components in the fluid path of a phacoemulsification system.
[0014] FIGS. 2A-2C are perspective views of the distal end of a phacoemulsification needle and irrigation sleeve according to the principles of the present invention.
[0015] FIGS. 3A-3C are cross section views of a prior art infusion sleeve.
[0016] FIGS. 4A-4C are cross section views of an infusion sleeve according to the principles of the present invention.
[0017] FIGS. 5A-5C are cross section views of an infusion sleeve according to the principles of the present invention.
[0018] FIGS. 6A-6C are cross section views of an infusion sleeve according to the principles of the present invention.
[0019] FIGS. 7A-7C are cross section views of an infusion sleeve according to the principles of the present invention.
[0020] FIG. 8 is a cross section view of an infusion sleeve according to the principles of the present invention.
[0021] FIG. 9 is a cross section view of an infusion sleeve according to the principles of the present invention.
[0022] FIG. 10 is a cross section view of an infusion sleeve according to the principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Reference is now made in detail to the exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts.
[0024] In one embodiment of the present invention, FIG. 1 is a diagram of the components in the fluid path of a phacoemulsification system. FIG. 1 depicts the fluid path through the eye 1145 during cataract surgery. The components include an irrigation fluid source 1105 , an irrigation pressure sensor 1130 , an irrigation valve 1135 , an irrigation line 1140 , a hand piece 1150 , an aspiration line 1155 , an aspiration pressure sensor 1160 , a vent valve 1165 , a pump 1170 , a reservoir 1175 and a drain bag 1180 . The irrigation line 1140 provides irrigation fluid to the eye 1145 during cataract surgery. The aspiration line 1155 removes fluid and emulsified lens particles from the eye during cataract surgery.
[0025] When irrigation fluid exits irrigation fluid source 1105 , it travels through irrigation line 1140 and into the eye 1145 . An irrigation pressure sensor 1130 measures the pressure of the irrigation fluid in irrigation line 1140 . An optional irrigation valve 1135 is also provided for on/off control of irrigation. Irrigation pressure sensor 1130 is implemented by any of a number of commercially available fluid pressure sensors and can be located anywhere in the irrigation fluid path (anywhere between the irrigation source 1105 and the eye 1145 ).
[0026] A hand piece 1150 is placed in the eye 1145 during a phacoemulsification procedure. The hand piece 1150 has a hollow needle (as seen in FIG. 2 ) that is ultrasonically vibrated in the eye to break up the diseased lens. A sleeve located around the needle provides irrigation fluid from irrigation line 1140 . The irrigation fluid passes through the space between the outside of the needle and the inside of the sleeve (as more clearly shown in FIG. 2A ). Fluid and lens particles are aspirated through the hollow needle. In this manner, the interior passage of the hollow needle is fluidly coupled to aspiration line 1155 . Pump 1170 draws the aspirated fluid from the eye 1145 . An aspiration pressure sensor 1160 measures the pressure in the aspiration line. An optional vent valve can be used to vent the vacuum created by pump 1170 . The aspirated fluid passes through reservoir 1175 and into drain bag 1180 .
[0027] FIG. 2A is a perspective view of the distal end of a phacoemulsification hand piece according to the principles of the present invention. In FIG. 2 , a phacoemulsification needle 1210 is surrounded by an irrigation sleeve 1230 . The phacoemulsification needle 1210 has an open end 1220 through which lens particles are aspirated from the eye during cataract surgery. The irrigation sleeve 1230 has an optional opening 1240 through which irrigation fluid flows into the eye. The needle 1210 and sleeve 1230 are both inserted into the anterior chamber of the eye during cataract surgery. When power is applied to the hand piece, the needle 1210 vibrates ultrasonically. This is more clearly seen in FIGS. 2B and 2C . In FIG. 2B , needle 1210 vibrates in longitudinal mode (back and forth). In FIG. 2C , needle 1210 vibrates in torsional mode (or in a twisting or sweeping manner).
[0028] The two different modes (longitudinal and torsional) produce two different needle motions as shown in FIGS. 2B and 2C . In general, longitudinal mode can act to cut a cataractous lens by impacting the end of the needle 1210 against the lens much like a jackhammer. Torsional mode can act to cut a lens with a side to side sweep of the end of the needle 1210 . Depending on the needle geometry, the twisting motion imparted to the needle 1210 in torsional mode generally produces a side to side sweep of the end of the needle 1210 . In other instances, the end of the needle 1210 sweeps in an arc. Regardless, torsional mode may be more effective in cutting a lens because it allows aspiration through open end 1220 of needle 1210 to hold the lens material on the needle 1210 for more effective cutting. In addition, in torsional mode, each sweep of the needle 1210 acts to cut the lens. In contrast, longitudinal mode produces a jack hammer motion that impacts the lens only in a forward direction (and not in a return direction). Moreover, longitudinal mode may act to repel the lens material away from the needle which may reduce cutting efficiency.
[0029] The effect of the sweeping motion of needle 1210 on the irrigation sleeve is shown in FIGS. 3A-3C . FIGS. 3A-3C are cross section views of a prior art infusion sleeve. A needle would occupy the lumen 310 of sleeve 300 . As shown in FIG. 3A , sleeve 300 has a generally circular cross section as does the lumen 310 bounded by sleeve 300 . In this manner, sleeve 300 is generally cylindrical or tube shaped with an interior passage or lumen 310 that has a circular cross section. In FIGS. 3A-3C , the boxes on the sleeve wall located at twelve, three, six, and nine o'clock are for illustrating the sleeve movement seen in FIGS. 3B and 3C .
[0030] As shown in FIGS. 3B and 3C , when a needle (not shown) located in lumen 310 is vibrated torsionally or in a sweeping manner (needle motion denoted by “M”), a circumferential, radial or rotating motion is imparted to sleeve 300 (sleeve motion is denoted by “R”). Needle motion M alternately compresses each side of the wall of sleeve 300 while expanding the other side of the wall of sleeve 300 . The top and bottom walls of sleeve 300 generally move circumferentially in an arc R. In this manner, torsional vibration of the needle (not shown) in lumen 310 causes significant motion of the sleeve 300 . Force is transmitted from the needle to the sleeve 300 in the direction of needle motion M resulting in a compression of a side wall of sleeve 300 as shown. In addition, the walls of sleeve 300 (top and bottom walls shown in FIGS. 3B and 3C ) move circumferentially around the needle. Such motion may damage eye structures such as the iris.
[0031] FIGS. 4A-4C are cross section views of an infusion sleeve according to the principles of the present invention. In FIG. 4A , sleeve 400 has an internal lumen 410 , two thick walls 420 , and two thin walls 430 . Lumen 410 has an oblong cross section, although other cross sections, such as an elliptical cross section, may also be employed. The needle would be located in lumen 410 . The exterior of the sleeve 400 has a generally circular cross section and is in the shape of a tube. In this example, two thick walls 420 are located at twelve and six o'clock, and two thin walls 430 are located at three and nine o'clock. In FIGS. 4A-4C , the boxes on the sleeve wall located at twelve, three, six, and nine o'clock are for illustrating the sleeve movement seen in FIGS. 4B and 4C .
[0032] While the location of thick walls 420 and thin walls 430 are shown at twelve and six o'clock and at three and nine o'clock, respectively, in other embodiments of the present invention, thick walls 420 and thin walls 430 may be located at any point on the sleeve as long as they are alternated. In other words, as one travels around the periphery of sleeve 400 , one would encounter a thick wall 420 followed by a thin wall 430 , followed by a thick wall 420 , etc. Any number of thick walls 420 and thin walls 430 may be employed. In addition, the thin walls 430 may not be of a uniform cross section, but instead may transition gradually into the cross section of the thick walls 420 . In this manner, the thick walls 420 and thin walls 430 may have cross sections that vary along their lengths. The thin walls 430 may also have lengths that are greater than, less than, or the same as the thick walls 430 .
[0033] As shown in FIGS. 4B and 4C , when a needle (not shown) located in lumen 410 is vibrated torsionally or in a sweeping manner (needle motion denoted by “M”), a much smaller circumferential or rotating motion is imparted to the thick walls 420 of sleeve 400 (thick wall 420 motion is denoted by “R”). Needle motion M alternately deforms each thin wall 430 . The thick walls 420 of sleeve 400 generally move very slightly circumferentially in an arc R. In general, the thin walls 430 are deformable such that little circumferential motion is imparted to the thick walls 420 . Moreover, deformation of thin walls 430 also imparts very little force to adjacent eye structures. As such, the improved sleeve design of FIG. 4A reduces the force applied to eye structures by the sleeve 400 when in use.
[0034] FIGS. 5A-5C are cross section views of an infusion sleeve according to the principles of the present invention. In FIG. 5A , sleeve 500 has an internal lumen 510 , two thick walls 520 , and two thin walls 530 . Lumen 510 has an oblong cross section, although other cross sections, such as an elliptical cross section, may also be employed. The needle would be located in lumen 510 . The exterior of the sleeve 500 has a generally circular cross section and is in the shape of a tube. In this example, two thick walls 520 are located at three and nine o'clock, and two thin walls 530 are located at twelve and six o'clock. In FIGS. 5A-5C , the boxes on the sleeve wall located at twelve, three, six, and nine o'clock are for illustrating the sleeve movement seen in FIGS. 5B and 5C .
[0035] While the location of thick walls 520 and thin walls 530 are shown at three and nine o'clock and at twelve and six o'clock, respectively, in other embodiments of the present invention, thick walls 520 and thin walls 530 may be located at any point on the sleeve as long as they are alternated. In other words, as one travels around the periphery of sleeve 500 , one would encounter a thick wall 520 followed by a thin wall 530 , followed by a thick wall 520 , etc. Any number of thick walls 520 and thin walls 530 may be employed. In addition, the thin walls 530 may not be of a uniform cross section, but instead may transition gradually into the cross section of the thick walls 520 . In this manner, the thick walls 520 and thin walls 530 may have cross sections that vary along their lengths. The thin walls 530 may also have lengths that are greater than, less than, or the same as the thick walls 530 .
[0036] As shown in FIGS. 5B and 5C , when a needle (not shown) located in lumen 510 is vibrated torsionally or in a sweeping manner (needle motion denoted by “M”), small linear motion is imparted to the thick walls 520 of sleeve 500 (thick wall 520 motion is denoted by “D”). Needle motion M alternately deforms each thin wall 530 , much as the thin walls 430 of FIGS. 4B and 4C are deformed. The thick walls 520 of sleeve 500 generally move very slightly to and fro in a linear manner D. In general, the thin walls 530 are deformable such that little motion is imparted to the thick walls 520 . Moreover, deformation of thin walls 530 also imparts very little force to adjacent eye structures. As such, the improved sleeve design of FIG. 5A reduces the force applied to eye structures by the sleeve 500 when in use.
[0037] FIGS. 6A-6C are cross section views of an infusion sleeve according to the principles of the present invention. In FIG. 6A , sleeve 600 has an internal lumen 610 , four thick walls 620 , and four thin walls 630 . Lumen 610 has a sprocket-type cross section, although other cross sections, such as a star-shaped cross section, may also be employed. The needle would be located in lumen 610 . The exterior of the sleeve 600 has a generally circular cross section and is in the shape of a tube. In this example, four thin walls 630 are located at twelve, three, six, and nine o'clock. The four thick walls 620 are located adjacent to the four thin walls 630 .
[0038] In other embodiments of the present invention, thick walls 620 and thin walls 630 may be located at any point on the sleeve as long as they are alternated. In other words, as one travels around the periphery of sleeve 600 , one would encounter a thick wall 620 followed by a thin wall 630 , followed by a thick wall 620 , etc. Any number of thick walls 620 and thin walls 630 may be employed. In addition, the thin walls 630 may not be of a uniform cross section, but instead may transition gradually into the cross section of the thick walls 620 . In this manner, the thick walls 620 and thin walls 630 may have cross sections that vary along their lengths. The thin walls 630 may also have lengths that are greater than, less than, or the same as the thick walls 630 .
[0039] As shown in FIGS. 6B and 6C , when a needle (not shown) located in lumen 610 is vibrated torsionally or in a sweeping manner (needle motion denoted by “M”), small linear motion is imparted to the thick walls 620 of sleeve 600 . Needle motion M alternately deforms thin wall 630 , much as the thin walls 430 of FIGS. 4B and 4C are deformed. The thick walls 620 of sleeve 600 generally move very slightly to and fro in a linear manner. In general, the thin walls 630 are deformable such that little motion is imparted to the thick walls 620 . In FIGS. 6B and 6C , the thin walls 630 located at 6 and 12 o'clock are deformed slightly. In general, thin walls 630 may be compressed or stretched slightly depending on the movement M of the needle (not shown). Moreover, deformation of thin walls 630 also imparts very little force to adjacent eye structures. As such, the improved sleeve design of FIG. 6A reduces the force applied to eye structures by the sleeve 600 when in use.
[0040] FIGS. 7A-7C are cross section views of an infusion sleeve according to the principles of the present invention. In FIG. 7A , sleeve 700 has an internal lumen 710 , four thick walls 720 , and four thin walls 730 . Lumen 710 has a sprocket-type cross section, although other cross sections, such as a star-shaped cross section, may also be employed. The needle would be located in lumen 710 . The exterior of the sleeve 700 has a generally circular cross section and is in the shape of a tube. In this example, four thick walls 720 are located at twelve, three, six, and nine o'clock. The four thin walls 730 are located adjacent to the four thick walls 720 .
[0041] In other embodiments of the present invention, thick walls 720 and thin walls 730 may be located at any point on the sleeve as long as they are alternated. In other words, as one travels around the periphery of sleeve 700 , one would encounter a thick wall 720 followed by a thin wall 730 , followed by a thick wall 720 , etc. Any number of thick walls 720 and thin walls 730 may be employed. In addition, the thin walls 730 may not be of a uniform cross section, but instead may transition gradually into the cross section of the thick walls 720 . In this manner, the thick walls 720 and thin walls 730 may have cross sections that vary along their lengths. The thin walls 730 may also have lengths that are greater than, less than, or the same as the thick walls 730 .
[0042] As shown in FIGS. 7B and 7C , when a needle (not shown) located in lumen 710 is vibrated torsionally or in a sweeping manner (needle motion denoted by “M”), small linear motion is imparted to the thick walls 720 of sleeve 700 . Needle motion M alternately deforms thin wall 730 , much as the thin walls 430 of FIGS. 4B and 4C are deformed. The thick walls 720 of sleeve 700 generally move very slightly to and fro in a linear manner. In general, the thin walls 730 are deformable such that little motion is imparted to the thick walls 720 . In general, thin walls 730 may be compressed or stretched slightly depending on the movement M of the needle (not shown). Moreover, deformation of thin walls 730 also imparts very little force to adjacent eye structures. As such, the improved sleeve design of FIG. 7A reduces the force applied to eye structures by the sleeve 700 when in use.
[0043] FIG. 8 is a cross section view of an infusion sleeve according to the principles of the present invention. In FIG. 8 , sleeve 800 has an internal lumen 810 , four thick walls 820 , and four thin walls 830 . Lumen 810 has a square cross section. The needle would be located in lumen 810 . The exterior of the sleeve 800 has a generally circular cross section and is in the shape of a tube. In this example, four thick walls 820 are located at twelve, three, six, and nine o'clock. The four thin walls 830 are located adjacent to the four thick walls 820 . In addition, the thin walls 830 are not of a uniform cross section, but instead transition gradually into the cross section of the thick walls 820 . In this manner, the thick walls 820 and thin walls 830 have cross sections that vary along their lengths. The thin walls 830 may also have lengths that are greater than, less than, or the same as the thick walls 830 .
[0044] FIG. 9 is a cross section view of an infusion sleeve according to the principles of the present invention. In FIG. 9 , sleeve 900 has an internal lumen 910 , six thick walls 920 , and six thin walls 930 . Lumen 910 has a hexagonal cross section. The needle would be located in lumen 910 . The exterior of the sleeve 900 has a generally circular cross section and is in the shape of a tube. In this example, the six thin walls 930 are located adjacent to the six thick walls 920 . In addition, the thin walls 930 are not of a uniform cross section, but instead transition gradually into the cross section of the thick walls 920 . In this manner, the thick walls 920 and thin walls 930 have cross sections that vary along their lengths. The thin walls 930 may also have lengths that are greater than, less than, or the same as the thick walls 930 .
[0045] FIG. 10 is a cross section view of an infusion sleeve according to the principles of the present invention. In FIG. 10 , sleeve 1000 has an internal lumen 1010 , eight thick walls 1020 , and eight thin walls 1030 . Lumen 1010 has an octagonal cross section. The needle would be located in lumen 1010 . The exterior of the sleeve 1000 has a generally circular cross section and is in the shape of a tube. In this example, the eight thin walls 1030 are located adjacent to the eight thick walls 1020 . In addition, the thin walls 1030 are not of a uniform cross section, but instead transition gradually into the cross section of the thick walls 1020 . In this manner, the thick walls 1020 and thin walls 1030 have cross sections that vary along their lengths. The thin walls 1030 may also have lengths that are greater than, less than, or the same as the thick walls 1030 .
[0046] The sleeves 400 , 500 , 600 , 700 , 800 , 900 , and 1000 depicted in FIGS. 4A-4C , 5 A- 5 C, 6 A- 6 C, 7 A- 7 C, 8 , 9 , and 10 are made of an elastic material such as silicone or other suitable polymer. As such, the sleeves 400 , 500 , 600 , 700 , 800 , 900 , and 1000 are flexible and can deform as shown in FIGS. 4A-4C , 5 A- 5 C, 6 A- 6 C, 7 A- 7 C, 8 , 9 , and 10 . The sleeves 400 , 500 , 600 , 700 , 800 , 900 , and 1000 may also be described as generally flexible tubes. In addition, the cross section views shown in FIGS. 4A-4C , 5 A- 5 C, 6 A- 6 C, 7 A- 7 C, 8 , 9 , and 10 may represent the sleeve at any point or at particular points along the needle that is inserted into the eye. The sleeves 400 , 500 , 600 , 700 , 800 , 900 , and 1000 may have the same or a different cross section at a location that is not inserted into the eye (for example, at a location further posterior the end of the needle). For example, the distal one third of the sleeve may have a cross section shown in FIGS. 4A-4C , 5 A- 5 C, 6 A- 6 C, 7 A- 7 C, 8 , 9 , and 10 , while the proximal two thirds may have a different cross section (such as the cross section of a simple flexible tube without thick and thin segments). In another example, the sleeve has the same cross section along the entire length of the needle. Other combinations of cross sections along the length of the sleeve may also be employed.
[0047] From the above, it may be appreciated that the present invention provides an improved irrigation sleeve for phacoemulsification surgery. The present invention provides an irrigation sleeve with thick wall and thin wall segments that decrease the amount of motion transferred to adjacent eye structures when a needle located in the lumen of the sleeve is vibrated torsionally. The present invention is illustrated herein by example, and various modifications may be made by a person of ordinary skill in the art.
[0048] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.
[0049] It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
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An infusion sleeve has a flexible tube enclosing a lumen. The tube has a plurality of wall segments, each wall segment located between the lumen and an exterior surface of the tube and extending parallel to a central axis of the tube. The plurality of wall segments includes at least two thick wall segments and at least two thin wall segments alternately arranged such that each thick wall segment is adjacent to two thin wall segments, and each thin wall segment is adjacent to two thick wall segments.
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BACKGROUND OF THE INVENTION
The assembly of workpieces, such as machinery having rotating parts, frequently requires the precise fitting of antifriction rolling elements such as ball or roller bearings. Tolerances of the manufactured workpiece parts may cause variations in the axial dimensions of the workpiece which may exceed allowable variations for the fitting of bearings therein and therefore often some method of selective fitting or tailoring of a compensating component is required. One method commonly employed is to measure the assembly of components and provide a shim or spacer selected to precisely obtain the desired fit, which may be either a small amount of free end play or clearance or some prescribed value of a preloading force on the assembly.
An early example of an arrangement for preloading ball bearing arrangements in a workpiece is illustrated by U.S. Pat. No. 2,101,130 to Christman. The Christman arrangement provides a deformable or crushable separator element between ball bearing races so that in the assembly of the parts, this separator may compensate for inaccuracies of the workpiece parts. Christman employs a press to deform his spaceing element to a preferred load, whereupon the workpiece parts are crimped or otherwise permanently fastened in position. In other words, Christman relatively moves his workpiece parts until a certain preload force is achieved, whereupon the parts are permanently affixed to complete the workpiece assembly.
Improvements on the spacer or similar sealing elements, over known types such as employed in the Christman device are clearly described in my U.S. Pat. Nos. 3,561,793, 3,595,588, 3,751,048, 3,774,896, 3,794,311 and 3,900,232, as well as my two copending Applications, U.S. Ser. Nos. 447,571, now Pat. No. 4,067,585, and 838,306, now U.S. Pat. No. 4,125,929 filed Mar. 4, 1974 and Sept. 30, 1977, respectively, and U.S. Pat. Nos. 3,726,576 and 3,672,019. Briefly, my improved annular spacing elements are designed to experience elastic deformation with a relatively linear stress-strain relationship followed by plastic deformation under a relatively constant load or force, and when the originally applied deforming force is removed, they again exhibit a relatively linear stress-strain relationship, displaced by the amount of plastic deformation from their original stress-strain relationship. Thus, attempting to apply directly the Christman compensating technique to my spacer or load determining elements would result in either no plastic deformation of my elements, or a complete crushing of my elements. This is due to the fact that Christman increases the compressing force until a prescribed value is achieved, whereupon he fastens his workpiece portions together in that position and under that prescribed load. This approach worked for the Christman arrangement since the Christman spacer element was essentially an annular spring. Further, Christman preloads bearings to a prescribed pressure by allowing for variations in the relative position between two housing portions when those housing portions are affixed together. Such variations in the relative position of the housing portions are the exception rather than the rule in modern day equipment where typically two housing portions are bolted or welded together at their meeting faces, rather than one portion being press-fit into another portion to a variable depth. Thus, the Christman arrangement is unsuited to most bearing spacing or loading problems.
SUMMARY OF THE INVENTION
Among the several objects of the present invention may be noted the provision of a method of and apparatus for deforming a spacer element to adapt that element to a specific workpiece so that dimensional tolerances of a workpiece (variations in the dimensions of different workpieces) are compensated for by the amount of deformation of the spacer element; the provision of a methd and apparatus for deforming a spacer element by an amount tailored to a particular workpiece prior to assembling that spacer element in that workpiece; the provision of a method and apparatus for deforming a spacer element by an amount particularly suited to a particular workpiece in which the spacer element is disposed; the provision of an arrangement for adjusting bearings to close tolerances in a high production environment; the provision of an arrangement for adjusting bearings and in particular a compensating element for those bearings not requiring the assembly, disassembly and reassembly of the bearing arrangement; the provision of a system for rapidly and economically assembling a workpiece and compensating that workpiece for dimension variations therein; and the provision of a unique method and apparatus for imparting a plastic deformation to a spacer element with the amount of deformation adapting that element to a particular workpiece. These as well as other objects and advantageous features of the present invention will be in part apparent and in part pointed out hereinafter.
In general, one housing portion of a workpiece has a shaft, bearings, bearing races and an annular spacing element loosely placed therein in the same relative positions as those parts to occupy in the finished workpiece, and another housing portion assembled to the first housing portion to axially compress the spacing element. After the housing portions are assembled, the spacing element is further axially compressed a predetermined amount which additional compressing is independent of the amount of axial compression experienced when the two housing portions were assembled.
Also in general and in one form of the invention, a shaft, bearings, bearing races and an annular spacing element are placed within a portion of a workpiece housing in the same relative positions as they are to occupy in the finished workpiece. A first portion of an adjusting fixture is then abutted with a first portion of the workpiece, and a second portion of the adjusting fixture and a second portion of the workpiece are thereafter abutted with the fixture portion continuing to abut the first workpiece portion, so that the relative positioning of the two fixture portions indicates the relative positioning of the first and second workpiece portions. The fixture is then removed from abutment with the workpiece portions, while the relative positioning of the two fixture portions is maintained and a spacing element is deformed by an amount determined by the relative positioning of those fixture portions. The thus deformed spacing element may then be placed in contact with one of the previously abutted workpiece portions and engaged and confined within the workpiece housing by the juxtaposition and fastening together of the housing portions.
FIG. 1 is a section view of a portion of an illustrative workpiece partly assembled and engaged by a deformation determining fixture;
FIG. 2 is a section view illustrating a spacer element being deformed in the fixture of FIG. 1;
FIG. 3 is a view similar to FIG. 1 but illustrating a somewhat different fixture;
FIG. 4 is a view similar to FIG. 3 illustrating deformation of a spacing element employing the fixture of FIG. 3;
FIG. 5 is a section view of a press arrangement having fixtures for engaging a nearly completely assembled workpiece and for deforming a spacer element therein;
FIG. 6 is a section of the workpiece and portions of the press illustrated in FIG. 5;
FIG. 7 illustrates another press arrangement for external spacer height adjustment; and
FIG. 8 illustrates a further variation on the fixture and workpiece of FIGS. 1 and 2.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawing.
The exemplifications set out herein illustrate a preferred embodiment of the invention and such exemplifications are not to be construed as limiting the scope of the disclosure or the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a workpiece 11 may be any of a broad class of manufactured items, such as a speed reducer, pump or motor, and includes a shaft 13 journaled within a housing 15 by tapered roller bearings 17 disposed between an inner race 19 and an outer race 21. Workpiece 11 may, of course, have a similar bearing arrangement (now shown) but located near an opposite end thereof. The workpiece housing 15 will, when completed, include another housing portion (not shown) but mating with the surface 23 of the housing portion illustrated. This other housing portion will typically fit rather closely about the shaft 13 and when the workpiece is ultimately assembled, a spacer element will be disposed between this other housing portion and the bearing race 21 to hold the bearings, bearing races and shaft in position under either a prescribed load or with a prescribed amount of end play. To provide an annular spacer element of the proper axial length to fit between the bearing race 21 and the housing portion, the fixture 25 may be used.
Fixture 25 includes a first fixture portion 27 and a second fixture portion 29, both of a generally annular configuraton, telescoped together and in adjustable threaded engagement at 31. The threaded engagement 31 provides relative axial displacement between the fixture portions 27 and 29 when one of those portions is rotated relative to the other. A set screw 33 may be provided to fix the relative axial displacement of the portions 27 and 29 as desired, and an optional handle 35 for lifting fixture 25 is also illustrated
In use, the fixture portion end 37 is engaged with a workpiece part, such as bearing race 21, and fixture portions 27 and 29 relatively rotated until the end 39 of fixture portion 27 abuts the surface 23 of the workpiece 11, thus the distance between end 37 and end 39 is the dimension A which will vary for different workpieces due to the accumulated dimensional tolerances in the workpieces. Set screw 33 may now be tightened if desired to lock the two fixture portions 27 and 29 together, and the entire fixture 25 is removed from the workpiece and transferred to the press arrangement illustrated in FIG. 2. A further modification of the arrangement of FIG. 1 may be desirable for assemblies which require substantial force to be applied at the interface of fixture surface 37 and workpiece 21 so that looseness of the component workpieces is completely eliminated within workpiece 11. This may be accomplished by securing handle 35 to the housing part 23 or by application of external force to handle 35 as by spring loading. The rotation of the shaft parts within workpiece 11 may be required to assure that the component workpieces are in proper engagement before proceeding with the adjustment of fixture portion 27.
The press of FIG. 2 may be any suitable press arrangement for urging press ram 43 toward and away from press bed 41. For example, for small spacer elements a conventional hand-actuated arbor or mandrel press may be employed. Fixture 25 is placed on press bed 41 with the end 37 engaging the press bed 41. Press ram 43 is lowered until it contacts the end 45 of fixture portion 27. A spacer element 47 is disposed between the upper end 49 of fixture portion 29 and the ram 43 so that actuation of the press compresses or deforms the spacer element 47 to the axial dimension between ends 45 and 49, plus of course the axial elastic restoration which occurs when the press ram 43 is raised. Dimension B of FIG. 2, which is the axial length to which the spacer element 47 is compressed, is of course, related to dimension A, as measured in FIG. 1, and being in FIG. 2 the distance between end 39 of fixture portion 27 and the press bed 41 plus the axial length of fixture portion 27 minus the axial length of fixture portion 29. The spring back distance S for the particular spacer element 47 may for example be determined and/or controlled in accordance with the techniques set forth in my aforementioned copending applications, and hence the tailoring of the deformed spacer element 47 to the particular workpiece 11 is uniquely determined by the relative lengths of the fixture portions 27 and 29, and compensates for variations in dimension A for various workpieces in a relatively simple manner.
Whether the spacing element 47 imparts a load on the bearings of the finished workpiece, provides a slight axial spacing for the bearings or "just fits", the bearings within the workpiece is of course a matter of how much deformation is imparted to the spacer element 47, and the loading or spacing provided thereby is intended to be encompassed by either term. For example, to provide the "just right" spacing or loading of the workpiece bearings, dimension A and dimension B plus S should be identical, which in turn means that the amount of spring back S for the particular spacer element 47 should equal the axial length of fixture portion 29 minus the axial length of fixture portion 27. By the proper choice of the relative axial lengths of these fixture portions, any desired spacing or preload is achievable. It should now be apparent that the press of FIG. 2 must have sufficient capacity to impart the necessary force to permanently deform the spacer 47 and that any excess of force above that required will be sustained by the related engagement between the fixture pieces 27 and 29. Said fixture parts are usually made from strong metals such as steel and, therefore, allow a large excess of force to be applied without damage to the fixture. The related engagements obviously must be accurately made so that no looseness will be present to cause inaccuracy relating dimension B to dimension A, otherwise the axial looseness of said related engagement can be accounted for by a corresponding decrease in the axial length of fixture piece 29.
In discussing the fixture arrangement of FIGS. 1 and 2, it was assumed that all of the significant or troublesome dimensional variations from part to part were accumulated in the dimension A, however, for some workpieces, the housing portion not illustrated in FIG. 1, which mates with surface 23, may itself include significant tolerances. Further, for certain workpieces, direct access to the end bearing as depicted in FIG. 1 may be inconvenient and accordingly the modified fixture illustrated in FIGS. 3 and 4 may better suit certain workpiece environments.
In FIG. 3, the workpiece 11 of FIG. 3 is for illustrative purposes assumed to be subtantially like that illustrated in FIG. 1, with a housing portion 15 containing a shaft 13, tapered roller bearing 17, outer bearing race 21 and inner bearing race 19 substantially as previously described. The workpiece 11 further has mated to surface 23 a second housing portion 51, which is for example, a cover, end bell or other typically encountered workpiece housing part. The axial space into which the spacer element will ultimately be put is represented in FIG. 3 by the dimension X and may be measured by relatively rotating the threaded adjusting collars or fixture portions 53 and 55 until the upper surface fixture portion 53 engages the lip on the cover 51, and the lower end of fixture portion 55 engages the outer race 21, against which the spacer element will ultimately be placed. The force of said engagement may be selected according to the desired rolling resistance which is imparted to shaft workpiece 13 and thus assuring that all looseness of component workpieces is eliminated. The cover 51 may then be removed and the fixture portions 53 and 55 withdrawn therefrom and transferred to the press arrangement of FIG. 4 for forming the space element.
The press of FIG. 4 is, like the FIG. 2 press, any convenient conventional arrangement for forcing a ram 43 toward and away from a press bed 41. The dimension defining fixture portions 53 and 55, having measured dimension X in FIG. 3, are prevented from easily relatively rotating, thereby losing that dimension, again by a set screw arrangement as illustrated in FIG. 1, by a further locking ring independently threaded to one of the fixture portions, or by any other convenient arrangement to insure that the dimension is not lost during process. Fixture portion 55 is disposed on the press bed 41 and a pedestal 57 is placed on top of the two fixture portions so that the lowermost portion of pedestal 57 resides on the fixture portion 53. Thus, pedestal 57 is displaced upwardly from the press bed by dimension X. A further pedestal portion 59 is placed over the arrangement and resting on press bed 41, which further pedestal portion 59 supports a spacer element 61 to be deformed. Press ram 43 may then be lowered, deforming the spacer element 61 until the ram 43 engages pedestal portion 57, stopping the ram and indicating completion of the deformation process. If the axial length of the pedestal portions 57 and 59 are identical, the spacer element 61 will be compressed to the dimension X and will after deformation be of an axial length or height equal to the dimension X plus any resilient spring back distance for the particular spacer element. As a further example, if the spacer element 61 is to be designed to just fit the dimension X of the workpiece, pedestal 57 would be shorter than pedestal 59 by this spring back or resilient restoration distance for the spacing element 61.
As thus far discussed, deformation of the spacing element occurs outside the workpiece and after deformation that spacing element is assembled into the workpiece, however, it is also possible to deform the spacing element while it is in the workpiece and without the prior art problem of a partial disassembly and reassembly of that workpiece after deformation. Such an in place forming of a spacing element to an optimum height for a particular workpiece may be achieved by the press 63 of FIG. 5. Press 63 includes a press frame 65 for supporting workpiece 67 and a first press ram 69 actuable by hydraulic or pneumatic cylinder 70 to move downwardly and into engagement with the top or cover 71 of workpiece 67 to force that workpiece against the press frame 65. A second press ram 73 actuable by a further hydraulic automatic cylinder 75 may be moved upwardly and into engagement with a part of the workpiece which is distinct from those engaged by the ram 69 and frame 65, such as, for example, the inner bearing race 77 of FIG. 6.
After ram 69 has firmly seated the workpiece cover 71 to the workpiece 67, that ram is fixed in its location either by the continued energization of the cylinder 70 or by actuating cylinders, such as 79 and 81, the pistons of which serve to anchor the ram 69 in position. Similar hydraulic or pneumatic cylinders 83 and 85 are provided to anchor the actuating cylinder 75 in a variable position determined by the particular workpiece 67.
When the workpiece is initially placed on press frame or bed 65, ram 73 engages a part of that workpiece. Ram 73 and its actuating cylinder 75 are suspended in a somewhat "free floating" manner by cables, such as 87 and 89, passing over an arrangement of pulleys, such as 91 and connecting to a series of weights, such as 93. The total weight of the weights, such as 93, is slightly greater than the total weight of ram 73, along with its actuating cylinder 75 and related parts so that this ram and actuating cylinder extend up through the press bed and engage the workpiece before that workpiece is firmly seated on the press bed. The weight of the workpiece overbalances this arrangement so that the weights 93 raise, and the ram 73 and actuating cylinder 75 are lowered as the workpiece is lowered into its rest position on the press frame 65. When the ram 73, which engages, for example, the inner bearing race 77 of the workpiece, has been moved to its proper position relative to that particular workpiece, cylinders 83 and 85 are actuated to anchor the ram actuating cylinder 75 in that position.
Between the cylinder 75 and ram 73 is a spacer 95 which has been selected for a particular run of workpieces and which limits the retraction of ram 73 toward cylinder 75 by seating against cylinder 75 and the enlargement 97 on ram 73, respectively,when that ram is retracted toward the cylinder. Thus, for a given spacer 95, ram 73 is movable by cylinder 75 from a retracted position determined by the spacer to its most extended position with this length of potential travel being set by the spacer for a given run of workpieces to impart a fixed deformation to each of a series of spacing rings in each of a series of workpieces. When the workpiece 67 is seated on press bed 65 and the weights 93 raised by depression of the ram 73, shoulder 97, spacer 95 and cylinder 75, that cylinder 75 is clamped or anchored in position by the cylinders 83 and 85 to thereafter provide a fixed amount of upward movement of the ram upon actuation of the cylinder.
Considering now FIG. 6, and recalling that ram 73 will provide a fixed amount of upward travel when its cylinder is actuated, the assembly and sequence of events prior to this "finishing touch" deformation will be considered. Workpiece 67 has a housing or cover portion 71 which is forced into firm engagement with the other housing portion of the workpiece by depression of the ram 69. Within the housing 67 will be found a shaft and rotating assembly 99, for example a shaft with a gear, motor rotor, pump impeller or other typically encountered workpiece parts associated therewith. The shaft includes inner bearing races 77 and 101 and tapered roller bearings 103 and 105, which respectively engage outer bearing races 107 and 109 in the workpiece housing. A compressible spacing element or load ring 111 is disposed between the upper outer bearing race and a flange or lip 113 on the housing portion 71. Actuation of ram 69 depresses the cover or housing portion 71 into engagement with the remaining housing portion and compresses the spacer element 111 by a variable amount depending upon the dimensional tolerances or variations from workpiece to workpiece. When the housing portion 71 is in place, it may, for example, be attached by volts, such as 115, to complete the housing assembly. After the housing portion 71 is in position and the spacing element 111 is deformed by an amount particular to the individual workpiece, ram 73 is actuated to further compress the spacing element 111 by an amount calculated to yield the appropriate end play in the finished workpiece or the appropriate bearing loading force in that particular workpiece as desired. Thus, a prescribed loading by the spacer ring 111 determined by the fixed stroke of the ram 73 is provided wth the previous compressing of spacer element 111 by ram 69 compressing the housing cover against the press frame, having been a variable amount of deformation to compensate for the dimensional tolerances in the workpiece.
In FIG. 7, a generally H-shaped press frame 117 includes an upper press bed portion 119 and a lower press bed portion 121. A hydraulic cylinder 123 is secured to the top of the frame 117 and has a cylinder rod 125 extending downwardly therefrom connecting to a movable plate 127. This plate 127 is in turn rigidly connected to a lower movable plate 129 by rods 131 and 133, which pass through the central frame portion or upper bed portion 119. An annular spacing element 135 is placed, for example, on bed portion 119, while a gauge 137 is placed on bed portion 121. Clearly, the gauge 137 and spacing element 135 could be interchanged if desired. As illustrated then the gauge 137 limits the downward travel of the press ram and since the ram portions are rigidly tied together, this limits the compressing of the spacing element 135 to a precisely determined height, depending upon the height of the gauge element 137 as well as the relative spacing between the bed portions (K) and the relative spacing between the ram portions (L).
If the crushed or maximum deformation height of the spacing element is H, as illustrated in FIG. 7, namely the distance between the lower surface of ram portion 127 and the upper surface of bed portion 119, and further if the height of the gauge (G) is the separation between the upper surface of the lower bed portion 121 and the lower surface of ram portion 129, then L plus G equals K plus H. If G is preset to occupy the end space in a bearing assembly and further if it is desired that the bearings in that assembly having a running axial clearance of, for example, 0.003 inches, and the resilient springback of the spacing element 135, which might for example be around 0.008 inches is known, then the press frame dimensioning may be completely determined. Thus, if the height K is 2.600 inches, then the press ram portions are separated by dimension L, which is made equal to 2.600 minus 0.003 minus 0.008 or 2.589 inches. With these press dimensions and the height G determined for each workpiece, each resulting spacer ring will have the desired running clearance of 0.003 inches.
The lower ram portion 129 may be annular, that is cut out in the center to accept a fixture such as the fixture 53, 55 of FIGS. 3 and 4, or other gauging arrangements suitable to the particular workpiece involved may be employed.
In FIG. 8, a fixture 139, 141 which might form the gauging element 137 in the press of FIG. 7 is shown in conjunction with a slightly different workpiece to further illustrate applications of the present invention. In FIG. 8, a workpiece in a partially assembled state will accept a spacer to fill dimension A, and a snap ring in the shaft groove 143 to retain bearing race 145, and the other workpiece components within the workpiece. Such an assembly where the tapered roller bearing back faces adre positioned outermost to the assembly is frequently encountered in situations where the shaft 147 is stationary and the outer structure 149 rotates, as for example in some pulley clutch designs or roller assemblies.
The fixture 139, 141 will be employed in a press, such as illustrated in FIG. 2 to deform the spacing ring and is set to its desired height by engaging fixture portion 139 with the outer surface or cone back face of inner race 145. The telescoped members 139 and 141 are relatively rotated until the inner fixture portion 141 contacts the surface on shaft 147 on which the snap ring will ultimately rest. The sequence of engaging the two fixture portions to the workpiece is of course immaterial and once both portions engage their corresponding workpiece portions, the fixture dimension B determines the height to which the spacer ring will be compressed by the press of FIG. 2, while the overall length of the two fixture portions 139 and 141 determines the compression imparted by a press, such as illustrated in FIG. 7.
For example, dimension B would equal dimension A less the spacer ring springback dimension plus the clearance, if any, of the snap ring in groove 143, less the desired amount of end play in the finished product, if any.
Shaft 147 has a shoulder against which fixture portion 141 may be easily abutted, however, for some workpieces the diameter of shaft 147 on either side of the snap ring groove may be the same, in which case the snap ring may be assembled on the shaft before the gauging fixture is set, in which case the gauging fixture may be as illustrated in FIG. 8, with gauging portion 141 engaging the snap ring and appropriate dimensional changes made to compensate for the thickness of that snap ring. Assembly of the workpiece would then be completed by removing the snap ring, placing a deformed spacer over shaft 147 and replacing the snap ring.
A further advantage lies in the press adjustments of FIGS. 2, 4 and 7 wherein the spacers 47, 66 or 135 respectively may be sufficiently strong so as to make compression within a housing assembly impractical because of limitations in the load carrying ability of the housing parts for workpieces therein.
From the foregoing it is now apparent that a novel fixture arrangement and press as well as a novel process for forming an annular spacing element in a workpiece to an optimum height for that workpiece has been disclosed meeting the objects and advantageous features set out hereinbefore before as well as others and that modifications as to the precise configurations, shapes and details, as well as the precise steps of the method may be made by those having ordinary skill in the art without departing from the spirit of the invention or the scope thereof as set out by the claims which follow.
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A plastic deformation is imparted to each of a sequence of load determining elements with the amount of deformation matching each element to a corresponding one of a sequence of element receiving workpieces to compensate for dimensional variation between the workpieces. A first fixture portion is abutted to a first workpiece portion and a second fixture portion is abutted to a second workpiece portion to provide a dimension defining separation between the fixture portions which is a function of a variable dimension of the abutted workpiece. The load determining or spacing element is then deformed the amount required for the particular abutted workpiece and the sequence of steps repeated to provide a plurality of matched elements and workpieces. The amount of element deformation may be such that the elements are under a like compression when assembled in each workpiece, thereby preloading the workpieces by consistent amounts or the deformation of the load determining elements may be sufficient that each workpiece has a small amount of free movement after assembly of the elements within the workpieces.
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RELATED APPLICATION
[0001] The present application claims the benefit of U.S. Provisional Application No. 62/075,107, filed Nov. 4, 2014, the complete content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION OF THE INVENTION
[0002] The inventions covered in this application relate to Ear Buds, In Ear Monitors, Hearing Aids and all related personal listening devices (hereafter collectively referred to as “earbuds”).
[0003] More specifically, they relate to high fidelity earbud hearing protection and health while affording enhanced sound quality, isolation, fit, aesthetics, overall customizability characteristics, Bluetooth connectivity, the reduction of event-based hearing damage/noise pollution through their use at concerts, sports events, etc., live broadcast and location based syncing of at-event wireless audio streaming to smartphones and similar WiFi or Bluetooth devices,—as well as a novel displacement-based digital audio compression algorithm which electronically mitigates premature triggering of the acoustic reflex thereby allowing lower in-ear volumes to sound louder than conventional couplings which are known to cause hearing loss.
[0004] Earbuds provide utility as portable and private audio devices and are sometimes improperly employed to inadequately isolate the user from external sounds while listening to in/on-ear audio [U.S. Pat. Nos. 4,239,945; 4,742,887; 8,638,971B2]. Utilizing an ear tip, ear mold or ear cushion, earbuds partially or wholly seal the ear canal in an effort to increase the isolation from external sounds as well as increase the retention of both the device and the amplified sound within or around the ear. However, formal studies show their regular use leads directly to permanent hearing damage.
[0005] Large, high intensity transducer membrane excursions (ie. the vibratory back and forth movements of the speaker diaphragm) are necessary for the audible propagation of acoustic sound waves by earbuds. However, under partially or wholly sealed in-ear conditions, these relatively huge motions result in harmful oscillating pneumatic air pressures within the enclosed canal volume which overly impinge a significant percentage of the speaker diaphragm excursions directly onto the delicate and highly sensitive tympanic membrane, thereby overwhelming the natural compliance of the ear drum. Typical earbud/headphone speaker excursions range from microns to millimeters while normal tympanic membrane excursions range from only 100 to 250 nanometers, or roughly 1000 times smaller than typical speaker excursions.
[0006] Additionally, broadband, pneumatically coupled, in-ear sound pressures prematurely trigger the acoustic reflex, wherein, the tensor tympani muscle tightens the tympanic membrane, and the stapedius muscle pulls on and stiffens the ossicular chain, drawing the stapes away from the cochlea's oval window. This premature triggering often occurs as low as 60 dB when the ear canal is partially or wholly sealed instead of its typical audiologically established 88-90 dB threshold for an open ear canal.
[0007] Under these conditions, the net result of this premature triggering of the acoustic reflex is that sound waves are far less efficiently passed through to the inner ear, while their broadband pneumatic components continue to overly impinge on the tympanic membrane. Overall listening volumes are significantly less audible. The typical user response to this involuntary reflex is to turn the audio volume up much higher, resulting in international efforts to advise users of the dangers attendant upon listening to earbuds at excessive volume levels. This situation continues quite unresolved, resulting in habitual, overwhelming pressures on the tympanic membrane and leading to dramatic worldwide increases in permanent hearing loss.
[0008] The occlusion effect—i.e. bone conduction of one's own internal voice and body sounds resonating within the sealed ear canal (including transduction of external sound waves through vibrating bones, fluids, body cavities, tissues and in-ear devices) is the result of displacement based oscillating pneumatic air pressures from vibrating in ear surfaces which are then overly impinged onto both the tympanic membrane and the middle ear: sounds which are normally inaudible under unsealed conditions are pneumatically amplified as much as 1000 times (60 dB) over their normally unsealed volume levels. For example, one is able to easily hear the normally inaudible internal sounds of their own jaw motions or blood pumping amplified many times by simply plugging and sealing their ears with their fingers or foam ear plugs.
[0009] The confining of acoustically driven mechanical surface vibrations into relatively small, trapped volumes such as the ear canal results in unintended pneumatic displacement based in-ear acoustical amplifications similar to the intentional amplifications provided by stethoscopes, woodwinds, brass instruments, etc. All of these instruments gain their intended amplification through the principle of the pneumatic coupling of enclosed displacement based pneumatic pressures. This principle results in hearing loss when unwittingly applied to the ear because it is masked by the acoustic reflex and unrealized by the listener over time.
[0010] As described above, when the outer portion of the ear canal is sealed, in-ear sounds are significantly amplified by their aforementioned transformation into oscillatory pneumatic pressures, regardless of whether or not an active audio speaker is also present. However, this phenomena becomes greatly exaggerated when the normal diaphragm excursions of earbud speakers are introduced concurrent with mandibular (jawbone) deformations of the occluded ear canal walls such as those which occur during talking, singing, chewing, and yawning,—since all of these common physiological conditions independently create large increases in pneumatic in-ear pressures when the ear canal surfaces are exposed yet externally sealed and their accumulating pressures are thereby kept from immediately equalizing with normal external barometric pressure.
[0011] When earbuds conventionally seal the ear canal, these physiological conditions compound with transducer based in-ear sound pressures and together, dramatically increase the overall oscillating pneumatic pressure on the tympanic membrane by as much as 1 kPa or more. As already observed, this condition prematurely triggers the acoustic reflex, thereby demanding excessive listening volumes leading to hearing loss.
[0012] Conventional solutions to reducing the occlusion effect while wearing earbuds involve the introduction of leaks or vents into the chamber in front of the speaker. These leaks are acoustic as well as pneumatic and result in reduced volume levels, degraded bass frequency response and inadequate isolation and thereby demand higher listening volumes since the speaker is now driving a greatly enlarged or even unenclosed chamber. Here again, the typical user response has been to resort to excessive listening volumes. Unavoidable, accidental improved sealing conditions such as occur when shoving the device in deeper or leaning the ear containing the earbud up against a pillow or headrest often results in extremely high volumes which create pain and hearing loss before the person can easily respond, since the acoustic reflex greatly masks the condition.
[0013] Additionally, many conventional acoustic ear-coupling approaches use a hard, smooth surface for the ear tip or ear mold. Under conditions of mandibular deformation, such a surface forms an inconsistent seal, thus an intermittent leak between the coupler and the ear canal is inevitable, resulting in inconsistent coupling, degraded sound quality and inadequate isolation.
[0014] Some earbud designs utilize screened airflow channels independent of ear tip design to vent the front chamber air within the speaker housing to the outside, barometric pressure air. The Apple earbud design of 2013, for example, incorporates both venting methods [U.S. Pat. No. D691,594S] of the screened airflow channels and the hard, smooth ear tip surface. As described above, these solutions demand increased listening volumes.
[0015] Under wholly or partially sealed conditions, pneumatic pressures impede the motion of an earbud speaker. As the speaker moves within a sealed chamber, it inadvertently and variably compresses the trapped air into a smaller volume. As air is semi-incompressible, it resists, preventing the speaker from performing its intended linear excursion. Unlike unsealed conditions, the pressures created are nonlinear. Thusly impeded, the speaker exhibits slower transient responses, generating muddled, damped, lower quality sounds, which are especially nonlinear in the bass frequencies. Additionally, the natural performance of the Helmholtz resonance of the ear canal is significantly degraded.
[0000] In contrast, small air vents or screens are routinely employed in the back chamber of earbud speakers to allow similarly compressed air to escape and new air to flow in during rarefactions, thereby allowing the speaker to move more freely.
[0016] Under sealed conditions, the premature triggering of the acoustic reflex results in the stiffened compliance of the tympanic membrane variably determining the level of impedance on the speaker diaphragm facing the ear canal chamber, contributing significantly to the nonlinear functioning of both the speaker diaphragm and the tympanic membrane and thereby further degrading audio performance.
[0017] The aforementioned open-air pressure vents and leaks also act as acoustic vents. Employed in the chamber comprising the ear canal, sound amplitude and quality, particularly in the lower spectral regions, is significantly reduced with their use and listeners once again choose high audio volumes to recover the signal.
[0018] The Ambrose Diaphonic Ear Lens (ADEL) In-Ear Bubble invented by Stephen Ambrose (U.S. Pat. Nos. 8,340,310 B2 and 8,391,534 B2) significantly mitigates the shortcomings of conventional coupling systems such as common ear molds and ear tips. The inflatable ADEL ear tip is made of a highly flexible material, which when inflated, forms an effective, consistent and comfortable acoustic seal with the ear canal, despite physical exercise and mandibular deformations. The pressure exerted on the ear canal is sufficiently minimal that the presence of an ADEL disappears from the user's perception.
[0019] The ADEL is more compliant than the tympanic membrane by several orders of magnitude and is able to both absorb pneumatic pressures from within the sealed canal and reflect a greatly reduced return wave back onto the tympanic membrane. Unwanted reflections and resonances are substantially reduced.
[0020] The extremely low mass, low impedance mechanical excursion response of the ADEL membrane is much faster than both the speaker diaphragm and the tympanic membrane and results in ideal (extremely fast and high resolution) in-ear frequency/transient/dynamic range response—therefore significantly improving the performance and sound quality of any speaker mechanically coupled to the ear.
[0021] The inflatable ADEL very easily and comfortably enters, fills and displaces the full volume of the ear canal and thereby significantly reduces the occlusion effect. The tympanic membrane receives a more natural and healthy level of sound, the stapedius reflex does not prematurely trigger, the occlusion effect is minimized or removed, and the user perceives a much improved quality of sound throughout their listening experience without having to resort to excessive sound levels.
[0022] The passive, un-inflated ADEL absorbs the aforementioned pneumatic components of enclosed in-ear sound waves and thereby effectively lessens the occlusion effect as well as all the other unwanted conditions described above.
[0023] Many earbuds on the market are advertised as providing sound isolation. The isolation from exterior sounds is achieved by sealing the ear with unattractive, uncomfortable and noncompliant ear molds or over-sized foam or mushroom-shaped ear tips or with moldable materials such as self-curing silicones or wax.
[0024] In addition to being uncomfortable, conventional coupling methods often become dislodged, variably leak or introduce the occlusion effect (the unwanted booming bass of one's own voice), provide inadequate and inconsistent isolation/acoustic sealing and degrade the quality of in-ear acoustics by damping, exaggerating, muffling and blurring the source sound. Dedicated, sound isolating earbuds also operate under an all-or-nothing premise. The user must dislodge them to hear external sounds and replace them to hear the speaker and block off external sound.
[0025] Most available earbuds fit their users poorly and uncomfortably and their aesthetics tend to come at sacrifices to other earbud qualities. The diameter of the coupling element inserted into the ear may be too small or large, the element may be too short or angled incorrectly to match the user's ear topology. Ear couplers may be designed to be intentionally too large such as the foam plug or mushroom-cap tips to create a more complete seal and to resist falling out with motion. The oversized ear tips place a high pressure against the ear canal flesh and quickly become uncomfortable. Some models are designed with uncomfortable, non-customizable stabilizers or ear hangars in an attempt to take the weight of the earbud off the ear canal and improve stability; users commonly choose from a range of differently sized foam or mushroom-cap ear tips. Modifications of the length, direction, and curvature of the ear tips or overall custom fits are not available options to the general earbud consumer. While many earbuds are advertised as providing sound isolation, none are marketed for their ability to provide the user environmental awareness, and further none provide directionality-sensitivity. This creates a safety problem wherein the user is unable to hear warning sounds, other people, or other audible indications of impending harm.
[0026] The original in-ear monitor (IEM) invented by Stephen Ambrose in the 1960's and used for performances by musicians was the precursor for modern earbuds. IEMs tend to have customized, molded couplers that exactly fit performers' ears to attain the highest degree of isolation. These IEMs are uncomfortable in as much as the ear mold materials are rigid, fit tightly and do not flex with normal jaw motions; create very high levels of occlusion; and are unattractive as they tend to fill the visible ear canal with a vaguely flesh-colored plastic or silicon. An early version of Mr. Ambrose's IEM functioned as a portable listening device, a hearing aid and as functional jewelry [U.S. Pat. No. 4,852,177; 1989]. It employed a secondary acoustic path that vented pressures on the ear to a correct location in the earphone and prohibited a feedback cycle with the microphone that passed environmental sound into the sealed ear. These IEMs contributed less to hearing loss through this patented method by partially mitigating the pneumatic effects of sound constrained within the relatively small, trapped volumes of the sealed ear canal.
[0027] Most components that comprise conventional earbuds, whether they are custom-made or commercial, off-the-shelf products are not modifiable by the user. The user must choose at the time of purchase the set of earbud appearance, fit, quality and sound isolation that they are able to buy. Any desired variations require the purchase of another pair of earbuds.
[0028] Current Bluetooth connected earbuds are limited in both power and resolution. Bluetooth technology passes a low-resolution, compressed, digitized signal that degrades both the temporal resolution and the dynamic range of streamed music. Its receiver system can be a heavy user of power that requires frequent recharging. Many manufacturers opt to use a lower power version to minimize user frustrations but that comes at the cost of even less power for speaker operations. Speakers are then chosen that can only operate within remaining power budget, which further reduces the potential dynamic range of music.
[0029] Sound pressure levels of amplified live musical performances are commonly set at excessive volumes in an effort to produce a sensational experience for attendees. Because of the need for the sound emanating from speakers placed at the front of the stage to be loud enough to reach audiences in the back of the venue, attendees located closer to the stage are often subjected to deafening volumes for many hours. Such overstimulation triggers TTS (Temporary Threshold Shift wherein the listener's hearing sensitivity is involuntarily reduced) amongst the attendees, which then demands louder volumes to create the same sensation.
[0030] A resultant cacophony of competing sound sources further escalates these amplified sound pressure levels. In addition to highly amplified stage volumes, crowd noise, pyro technical explosions, etc., concert-goers also experience significant levels of physically transduced sounds (vibrations that impact and pass through the body).
[0031] These competing sound sources reflect off the walls, ceilings or other surfaces containing or surrounding the venue. In an attempt to cut through this confusion, amplified volumes are often pushed even louder.
[0032] In Ear Monitors were invented by Stephen Ambrose in 1965 and developed in the 70s with the help of Stevie Wonder to allow performers to hear their own music on stage and isolate away the competing sounds with the same quality they enjoy when using headphones in recording studios.
[0033] However, because these devices can create pneumatic pressures which trigger the acoustic or stapedius reflex and add the booming occlusion affect one's voice and music, they tend to subject the performers to excessive in-ear volume levels and must be dislodged or removed in order to hear ambient sounds. They are usually embodied in ear molds, which are uncomfortable and look unattractive. The isolation they offer is not optimum for all situations.
[0034] Auditory damage to both the performer's and the attendee's hearing caused by excessive volumes at musical events is well understood and documented. Civic regulations on noise pollution, timings and locations of events are continuing to limit venue opportunities for hosting a full-featured musical performance.
[0035] Currently available earbuds have limited ability to mitigate the excessive noise levels of amplified musical events. On the contrary, they tend to add their own inherently excessive listening levels to the excessive volumes present at the amplified even, thereby compounding the risk of hearing loss.
[0036] Conventional hearing protectors muffle the sound, are uncomfortable and can create excessive in-ear pressures. Additionally, occupants of areas neighboring a venue cannot practically or ethically be required to wear hearing protection devices.
[0037] Conventional in ear monitors do not allow an adjustable mixture of both the ambient and the electronically broadcast renditions of their performance. Often performers can be seen wearing only one IEM or hanging the other over their shoulder in order to hear their surrounding environment.
[0038] When worn out in the audience, IEMs sound far better than the over-amplified concert despite not being synchronized with the amplified sound coming off the stage. However, the further one is from the stage, the greater the lag between the broadcast sound and the amplified sound emanating from the stage speakers.
[0039] The capability of synchronizing these two sound sources and allowing for user-adjustable volumes and mixtures between the two (as allowed by the novel invention described herein) has not been possible before now.
[0040] Prior attempts at broadcast performances used a single broadcast source using radio transmissions and timing delays were incurred by the difference in the speed of sound (live music) versus the speed of light (radio transmissions). In a large enough venue, attendees receive the radio transmission before the live music reached them, which creates an untenable timing gap.
[0041] Conventional earbuds degrade and muffle the amplified concert sound as well as the broadcast in-ear speaker sound due to occlusion, speaker impedance mismatch with the tympanic membrane and the aforementioned and resultant over-stimulation of the acoustic reflex. This creates a disruptive quality gap when trying to simultaneously listen to a broadcast and a live performance. Excessive volumes of both audio sources are additive and the risk of hearing loss is increased even further.
[0042] Amplitude-based compression algorithms that limit the dynamic (soft to loud) range of sounds produced from an audio system are commonly available. One example applies to television ads. The creators or broadcasters of television advertisements often use amplitude based dynamic range compression to set the overall audio volume of their advertisements at a higher level than the programs within which they're aired to draw viewers' attention to them. Counteracting software exists that reduces those sound volumes back in line with the programs. Similar sound reduction software algorithms, which are generally known as digital dynamic range compression, are applied to audio systems, MP3 players and smartphones for listening to music more safely.
[0043] These existing algorithms are amplitude-based and are set at ratios of sound level volumes relative to the threshold of the maximum volume level that the manufacturer deems safe or the listener chooses to hear.
[0044] Problems arise from the variation in the efficiency of sound transmission and hearing sensitivity across the audible frequency range. Bass sounds displace much more air than mid-range sounds to produce the same apparent loudness to the listener ( FIG. 8 , Graphic 1 ). Digital compression algorithms usually apply uniform loudness factor caps across all frequencies, for example, at 60 phons, which still permit nearly 300,000 times the displacement of air between 30 Hz at the compression cap and 3 kHz at the threshold of hearing. The sound level threshold of pain is; however, flatter than the threshold of hearing, which places audible bass sounds much closer to the pain limit than mid-range sounds. In a sealed ear canal, the pain threshold level is even lower, particularly in the bass, causing even more damage. The Occupational Safety and Health Administration (OSHA) begins requiring hearing protection at 85 dB of workplace environmental noise as prolonged exposure at that level can cause long-term damage. Early study results indicate that within a sealed ear, hearing damage begins as low as at 60 dB. An amplitude-based digital compression algorithm is too coarse a tool to adequately protect a listener's hearing.
[0045] In conclusion, no conventional earbud design to date is able to satisfactorily
1. Protect the listener's hearing from in-ear displacement based pneumatic pressures while delivering optimum, user adjustable sound quality, isolation, and ambient sound perception and directionality-sensitivity at the user's desired levels; 2. Fit each user perfectly; 3. Range in aesthetic properties from purely functional to unique, high-end customized jewelry; 4. Be fully modular to meet the servicing, fit, acoustic and aesthetic needs of the user at any point in time; 5. Provide high-fidelity audio with a stable, wireless signal; 6. Satisfactorily and variably mitigate the excessive sound levels of musical performances 7. And no existing digital compression algorithm adequately protects a listener from harmful levels of sound.
[0053] Likewise, no existing in-ear-monitor
1. allow an adjustable isolation from ambient sounds nor 2. permit an adjustable mixture of both the ambient and the electronically broadcast renditions of their performance.
SUMMARY OF THE INVENTION
[0056] The invention, an improved earbud, has a fully modular set of parts that of primary importance includes membranes and variable vents which protect the listener's hearing while improving the quality and isolation of sound according to the user's desired characteristics whether wired or wireless and through its modularity, can achieve a uniquely personal fit and act as a visual vehicle of personal statement as well as drastically diminish the noise pollution of musical events and works with an improved, displacement-based digital compression algorithm. The membranes described herein may be a flexible compliant member as described in U.S. Pat. No. 8,744,435, the entire content of which is hereby incorporated by reference.
[0057] The variable vents, the membranes and speakers all dilute harmful pneumatic pressures off the eardrum and the speaker while the membranes maintain an acoustic seal necessary for the highest fidelity sound. A user can create their desired sound profile through end cap, speaker and filter hardware as well as venting configuration choices. A user can adjust for ambient sounds and achieve directionality-sensitivity of environmental audio signals through a second embodiment of the Ambrose Earbud.
[0058] The invention can be used in the passive mode (i.e. —the earbud is worn as normal in the ear but the speaker is not powered on) as a hearing protection device by closing the vents to the desired amount or similarly with an alternative and simpler embodiment, which has no speaker.
[0059] All parts of the improved earbud invention are fully modular and easily snap together and apart for easy assembly and user-driven interchangeability to suit listener preferences. The cochlea of most humans is located behind the eyes, however, the external ear and ear canal pathway geometries vary wildly from person to person. The Ambrose Earbud parts have a range of shapes and sizes to create the perfect fit and all parts rotate without limit about their intersections enabling a user to choose the height and directionality of the ear horn fit with their ear as well as the weight balance, separation, and venting of the earbuds. Licensed end-cap customizers will be able to create versions that are visually unique such as high-end jewelry or political statements and have precisely defined acoustic resonance profiles.
[0060] The connectivity of the improved earbud will also be modular. User's can choose a traditionally corded version, a Bluetooth version with the Bluetooth receiver on a cord between the earbuds or a fully wireless model, which has the Bluetooth receiver within the earbud housing as an additional layer. User's can switch between the connectivity options by screwing the relevant cable in to or out from the bottom of the earbud housing, which also has a spring contact plate. With the fully wireless options, user's can screw in an antenna that curls around the outer ear, improves the stability and range of the Bluetooth signal and acts as an earbud stabilizer. Connectivity through the audio cable provides the highest quality sound and the lowest price but many users find cables to be cumbersome as they are easily tangled and caught. The Ambrose earbuds will have high quality speakers at even the entry level despite power and resolution limits presented by Bluetooth connectivity. With better speakers than are normally paired to Bluetooth receivers, the sound quality passed to the user becomes the maximum possible with Bluetooth rather than further diminished. The Bluetooth receiver fob on the cable that only connects to the earbuds provides a mid-level dynamic range to the sound quality and cost to the user as the fob can hold a larger battery and thus provides a higher power budget for both the signal and speaker. While the earbud to earbud cable is less cumbersome than the traditional audio cable, many users desire a fully wireless design. The fully wireless design provides a maximum of physical freedom to the user and, with the entirety of the Ambrose Earbud technology, will provide the highest sound quality and dynamic range of any available Bluetooth earbud.
[0061] The Ambrose Earbud is the key element in reducing music performance sound levels while maintaining the high quality sensory experience of attendance.
[0062] Musical events will be restructured to separate the transduced and acoustic effects of loud sound through vibration projection and the broadcasting of an event's music to Ambrose Earbud-connected audio devices. Infrasound frequencies (those with frequencies below standard human hearing) will be projected against venue walls and into the attending crowd to create the transduced vibrations that energize an audience.
[0063] The performed music will not be amplified but instead be broadcast to each audience member's portable music device such as a music-enabled mobile phone. The attendee will connect to the venue's broadcast system and the broadcast sound will be synchronized to the live sound via a number of possible methods. By keeping track of an attendee's location, the broadcast system can control the release timing of a signal to their device to match the arrival of the live sound. A position-based delayed sound will keep track of the attendee's location through such methods as Global Positioning System (GPS), Wi-Fi triangulation, or user-indicated seat position. An application-based synchronization will quickly compare the arrival time of the live sound detected by the user's device microphone and generate the necessary time delay for the broadcast sound. The synchronization program can continuously correct the offset for an attendee that is moving through a venue. The broadcast sound will be processed according to the timing delay and optionally, the geometric acoustic response of the venue at that location. The shapes and materials of the walls, ceiling, floor and other structural elements all reflect and slightly alter the music in unique ways so that the music in one location, a corner for example, sounds notably different from that in the center of the main open space.
[0064] The attendee will be wearing the Ambrose Earbud and listening to their own, user-specific broadcast sound. The sound quality will not be diminished because the membranes respond quickly and uniformly to all frequencies, which maintains the crispness and precise tones of the performance. Performers will be listening to the Ambrose Earbud embodiment of in-ear monitors modified with the Ambrose Tunable Impedance-Matching Acoustic Transformer for the human ears based on bio-mimicry. Performers will be able to select their desired isolation or passage of ambient sound through the Transformer's secondary Eustachian tube. An ADEL membrane, as in other embodiments, acts as a second tympanic membrane and damps both external and streamed sounds, which can optionally be a broadcast of their own music at any location within the venue. Performer personalities, special effects and the shared energy of a crowd will still complete the musical event experience, sound quality and hearing safety will be improved and noise pollution minimized.
[0065] A displacement-based digital compression algorithm places a cap on sound output at a given frequency that is consistent with both the maximum safe air displacement within a sealed ear canal and the comfortable maximum loudness (in phons) for that frequency. When used in conjunction with an Ambrose Earbud, sound quality is maintained at all frequencies because the membrane responds uniformly well across the spectrum.
[0066] The advantages of the invention are to provide a safer and higher quality listening and sound isolation experience, ambient sound perception, improved comfort, and the new ability to fully customize the sound, fit and aesthetics of an earbud as well as the ability to remove excess sound levels from live music events while improving the listening experience and to process the sound output with a digital compression algorithm that is displacement-and-loudness-based per frequency to further protect listener hearing health. The anticipated usage of the Ambrose Earbud includes listening to personal audio devices such as music players and telephones; in loud environments where a reduced but clear sound is desired such as at a rock concert; and for situations that require total sound isolation such as while operating a jackhammer or for musicians while performing on stage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] FIG. 1 is perspective view of a first embodiment of the invention (A 1 ) fully assembled.
[0068] FIG. 2 , comprising FIGS. 2A and 2B , shows embodiment A 1 with the ear horn and front end cap rotated in two different positions. FIG. 2A shows the front end cap rotated so that the ear horn intersection is in the upper left quadrant while the ear horn is rotated downward; and FIG. 2B shows the front end cap rotated so that the ear horn intersection is in the lower left quadrant while the ear horn is rotated upward.
[0069] FIG. 3 , comprising FIGS. 3A and 3B shows the A 1 embodiment with an audio cable rotated in different positions with respect to the stationary ear horn and front end cap. FIG. 2A shows the audio cable directed upwardly and FIG. 2B shows the audio cable directed downwardly.
[0070] FIG. 4 , comprising FIGS. 4A, 4B and 4C shows the embodiment A 1 with the back end cap rotated in different positions to show venting options; wherein FIG. 4A shows the closed position, FIG. 4B shows the open position and FIG. 4C shows the partially open position.
[0071] FIG. 5 is an exploded view of the A 1 embodiment.
[0072] FIG. 6 shows the A 1 embodiment with jeweling embellishment.
[0073] FIG. 7 , comprising FIGS. 7A, 7B and 7C shows different audio signal connectivity options for the A 1 embodiment.
[0074] FIG. 8 , is an example of a combined pneumatic air displacement and relative loudness based digital compression spectrum.
[0075] FIG. 9 is a perspective view of a second embodiment (A 2 ), fully assembled.
[0076] FIG. 10 , comprising FIGS. 10A, 10B and 10C shows the inner top basket of FIG. 9 rotated to different positions to show the top venting options; wherein,
[0077] FIG. 10A shows the open position, FIG. 10B shows the partially opened position and FIG. 10C shows the closed positon.
[0078] FIG. 11 , comprising FIGS. 11A, 11B and 11C shows the A 2 embodiment with the inner side basket rotated to different positions to show the venting options, wherein FIG. 11A shows the open position, FIG. 11B shows the partially opened position and FIG. 11C shows the closed position.
[0079] FIG. 12 is an exploded view of the A 2 embodiment.
[0080] FIG. 13 , comprising FIGS. 13A and 13B shows a turnable impedance matching acoustic transformer embodiment (A 3 ), wherein FIG. 13A shows the transformer fully assembled and FIG. 13B shows the transformer as intergrated into an ear-monitor that is being manipulated while worn.
[0081] FIG. 14 , including FIGS. 14A, 14B, 14C and 14D shows the embodiment (A 3 ) at multiple positions to demonstrate the venting options, wherein FIG. 13A is the fully closed position, FIG. 14B is a mostly closed position, FIG. 14C is a mostly opened position and FIG. 14D is a fully opened position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0082] FIG. 1 is a the view of the fully assembled, closed Ambrose Earbud, primary embodiment, which will be referred to as A 1 . Visible portions include the front end cap 3 and the back end cap 1 , the central control unit 2 with the cable port 6 and the arcs that enclose the vent channels 10 , the ear horn 4 and ear tip 5 .
[0083] The ear tip 5 snaps into the ear horn 4 which snaps into the front end cap 3 . The ear horn 4 rotates about its intersection with the front end cap 3 and the end cap 3 rotates relative to the central control unit 2 to attain the user's desired ear horn position. The ear horn 4 is formed of a firm material such as a hard plastic and is not intended to be visible, however, a user can choose to customize its appearance. The ear horn 4 is shown in FIG. 1 with a moderate curvature and length. Straighter and more curved, shorter and longer versions can be selected by the user to optimize the fit into their own ear canal. The ear tip 5 shown in FIG. 1 is of a mushroom-cap style of moderate size, is available on the market in a range of sizes and is made of a semi-firm material such as rubber, silicon or semi-firm plastic to form a seal with the ear canal. An alternative ear tip 5 which will also snap onto the ear horn 4 is the ADEL. Both the mushroom-cap style and the ADEL ear tips 5 are circularly symmetric and fit through compliance with the ear canal. The ear tip 5 can be rotated about its intersection with the ear horn 4 , but to no additional variation in function.
[0084] The front end cap 3 snaps into the central control unit 2 which then snaps into the back end cap 1 and the interior volume of these three parts contain the parts depicted subsequently in FIG. 5 . The back 1 and front 3 end caps are formed from firm materials such as metal, wood or hard plastic. The end caps 1 , 3 can host a range of appearances from functional to custom high end jewelry to individual statement through choices of materials, colors, polish, embellishments, and designs. The shape of the end cap 1 , 3 intersections must be circular to maintain the ability to intersect and rotate relative to the other components, however, the outside of the end cap can vary in shape and mass profile to provide the user their desired resonance characteristics. The dimensions of the end caps 1 , 3 are chosen to meet the size of the user's intertragical notch of the pinna (the dip in the exterior portion of the ear prior to the ear canal) and the central control unit 2 and interior element ( FIG. 5 ) selections must be scaled to match the end caps' size. The back end cap and central control unit rotate relative to each other to achieve the desired cable position of cable 7 and back end cap vent position 12 . Likewise, the central control unit 2 and front end cap 3 rotate relative to each other for the same purposes as well as to further improve the comfort of the earbud by allowing the ear horn to have an initial position appropriate for the user's personal ear geometry and which is described in greater detail subsequently.
[0085] FIG. 2 exemplifies two different positionings within the A 1 for the front end cap 3 and ear horn 4 with respect to a stably positioned cable port 6 , which is oriented so that the audio cable 7 would hang downward. The rotation of the front end cap 3 makes it possible for the ear horn intersection to match the height of the ear canal entrance within the intertragical notch and the rotation of the ear horn 4 causes the angle of the ear horn 4 to match the angle of the ear canal. Visible elements in FIG. 2 are the front end cap 3 , the ear horn 4 , the ear tip 5 and the cable port 6 . In FIG. 2A , the front end cap 3 is rotated about its intersection with the central control unit 2 so that its intersection with the ear horn 4 is at about 300°, which raises it about five-eighths of the front end cap's 3 diameter above the bottom of the intertragical notch. The ear horn 4 is rotated about its intersection with the front end cap 3 so that it is directed mostly downward at about 200°. In FIG. 2B , the front end cap 3 is rotated so that the ear horn 4 intersection is at the bottom, or 180° and the ear horn 4 is rotated mostly leftward or about 260°.
[0086] FIG. 3 depicts the A 1 with the audio cable 7 rotated to two different positions relative to a stably positioned front end cap 3 and ear 4 horn and also shows the use of the optional 9 ear hangar wire 9 . In FIG. 3A , the audio cable 7 hangs directly down from the Ambrose Earbud. In this position, it is anticipated that the ear horn 4 and ear tip 5 are deeply seated within the ear canal to maintain stable placement. In FIG. 3B , the audio cable 7 is positioned mostly upward and the optional ear hangar wire 9 is inserted into the cable strain protector sleeve 8 . The cable strain protector sleeve 8 and ear hangar wire 9 are not depicted to scale but rather are both long enough to reach over to the back of most user's ears. The ear hangar wire is shaped over the ear by the user to match their unique ear geometry and, because it is in the same cable strain protector sleeve 8 as the audio cable 7 , the audio cable 7 will also wrap over the user's ear. This configuration provides a stable placement of the earbud within the ear and reduces the weight and pressure stress on the ear canal. With the ear hangar 9 taking the weight of the earbud, the earbuds can be worn at a shallower position, which widens the distance between them and therefore also widens the stereo image of the sound source.
[0087] FIG. 4 demonstrates the different venting options available within the A 1 by rotating the back end cap 1 relative to a stably positioned central control unit 2 . The visible parts of the earbud in FIG. 4 are: the back end cap 1 ; the central control unit 2 ; the audio cable port 6 ; the vent channels 10 on the perimeter of the central control unit 2 ; the back, full-sized membrane 11 ; and the vent 12 of the back end cap 1 . When the A 1 is fully assembled, the vent channels 10 of the central control unit 2 are compression sealed between the back and front end caps. The back membrane 11 provides one part of the acoustic seal for the ear canal. A volume of space exists between the back membrane 11 and back end cap 1 which can be sealed, vented or partially vented according to the user's desires.
[0088] In FIG. 4A , the back end cap 1 is rotated so that the vent 12 is completely aligned with the vent channels 10 . In this position, the back end cap 1 volume of space is not vented to the outside, barometric pressure air. The back volume of space may be (1) pneumatically sealed, (2) vented fully into the front volume of space, (3) partially vented indirectly through the front volume to the outside, or (4) sealed while the front end cap 3 is fully open to the outside if the front end cap 3 is rotated so that its vent 12 is aligned with a different ent channel 10 , the same vent channel 10 , partially aligned with the same vent channel 10 , or aligned fully away from any vent channels, respectively.
[0089] (1) A full seal provides isolation from exterior sounds for the user with a passive speaker. An active speaker will experience a high degree of impedance as it is trying to compress the initial volume of air into a smaller amount of space. The speaker will move slowly and not as far as it is directed to do by the power signal at audio cable 7 . This reduces and blurs all sounds the speaker is intended to produce but especially affects the perceived bass sounds as the tympanic membrane is least sensitive to low spectral sounds and requires the highest amplitudes to produce the same perceived sound level. The membrane can do little to minimize the pneumatic pressures as it is contained within the same pressure environment.
[0090] (2) When the back volume is vented to the front volume (mutual venting) and the earbud is passive, a user will achieve a similar isolation to when both volumes are sealed and not vented to each other. The benefit of mutual venting is that it reduces the occlusion effect. When occlusion sounds occur, the pneumatic pressures reflect off and transmit through the membranes and speaker (acting as a membrane while passive) and the pressures can oscillate between the back, front and ear canal volumes, diluting the strength of the pneumatic pressures with each membrane interaction. If the user chooses to power the speaker—listen to something—with mutual sealed venting, the speaker becomes directional and the sound emitted through the back volume cancels those emitted through the front volume.
[0091] (3) An indirect, partial venting of the back volume through the front volume provides more isolation from exterior sounds than the same amount of direct, partial venting. Likewise, the speaker's impedance is reduced a small amount on the backwards motion while more is reduced in the frontwards motion. Both the exterior and the active speaker's sounds are amplified in the mid and high frequencies because the volume that is open—the front membrane and end cap-enclosed space—is smaller than that of the back as well as due to the doppler effect of the speaker relative to the tympanic membrane, which makes approaching sounds higher pitched and receding sounds lower.
[0092] (4) A sealed back volume with an open front volume will produce the highest impedance on the active speaker's backward motion with the least on its forward motion. Exterior and active speaker sounds will be crisp and strong in the mid and high frequencies while quiet and muddled at the low end of the sound spectrum.
[0093] In FIG. 4B , the back volume is fully vented to the outside barometric air pressure. Exterior sounds are clearly and strongly audible yet still reduced compared to not wearing an earbud. The back membrane 11 responds quickly to the pneumatic changes induced by the moving speaker diaphragm, impedance is removed from the speaker's backward motion and crisp, clear bass sounds are generated. As with the sealed back vent status depicted in FIG. 4 A, the vent status of the front chamber determines the clarity and strength of exterior and speaker sounds in the mid and high frequencies.
[0094] In FIG. 4C , the back volume is partially vented, which provides an intermediate amount of isolation, impedance reduction on the backward speaker motion, and bass volume and quality.
[0095] A parallel set of venting options exist for the front end cap 3 and the chamber enclosed by front membrane 19 with an additional set of pneumatic energy dilution, speaker impedance removal and isolation characteristics. The closed, open or partially open front venting choice reduce, strengthen or pass at an intermediate level the mid and high frequencies' clarity and strength. An open front vent provides the best individual stress relief for the tympanic membrane as the front membrane 19 is the most compliant surface within the ear canal volume. When both the back and front vents 12 are open, the pneumatic pressures created by the active speaker's acoustic signals are reduced the most through the pressure impedances of each vent, membrane and the speaker, maximally relieving the tympanic membrane of pneumatic stresses.
[0096] FIG. 5 is an exploded view of the A 1 that shows all the internal parts and depicts its full modularity. Each intersection between parts is circular for rotation ability and has ridges and grooves to provide the method of connection, unless otherwise noted. Adjacent parts are manually pressured together, their ridges jump over each other and both come to rest in the opposing part's groove. The connections are firm, will not spontaneously fail, yet the parts can readily be snapped back apart under intentional, opposing pressure. The A 1 is easy to assemble without the need for toxic glues and easy to service or exchange for alternative models of parts by either trained dealers or novice users.
[0097] From left, the back end cap 1 has a vent 12 and contains the back membrane 13 frame. The back membrane 11 rests inside the back membrane frame 13 . The back membrane gasket 14 fits snugly inside the back membrane frame 13 and secures the back membrane 11 in place. The back membrane 11 acts as a sealed dividing wall to create a back chamber with the back end cap 1 and an ear canal chamber with the ear canal, tympanic membrane and the 19 front membrane 19 . The back membrane 11 dilutes pneumatic pressures, provides an acoustic seal and maintains crisp, clear sound quality.
[0098] The back membrane-to-speaker spacer 15 and speaker frame rests against the back membrane frame 13 . The back spacer-frame 15 holds the speaker in the correct location 21 and has an open notch to allow the audio cable 7 to pass through, connect and power the speaker. The speaker front gasket 16 secures the speaker's position and is contained within the back spacer-frame 15 . The back spacer-frame 15 sits inside the central control unit 2 and fills most of its depth. The speaker front spacer 17 reinforces the speaker's position 21 and also sits inside the central control unit 2 , filling the rest of its depth.
[0099] The front membrane-to-speaker frame 18 fits inside the front end cap 3 and has an orifice that allows sound to pass from the speaker, through the intersection orifice 22 of the front end cap 3 with the ear horn 4 , the ear horn 4 itself, the ear tip 5 , and the ear canal to finally reach the tympanic membrane. The front membrane 19 rests inside the front membrane-to-speaker frame 18 across the membrane orifice depicted as a bean shape. The front membrane-to-end cap frame 20 fits snugly inside the membrane orifice and secures the front membrane 19 . The front end cap 3 has cavities to receive pins on the front membrane-to-speaker frame 18 that secure the two elements together in an orientation that enables the front membrane 19 to form a pneumatic pressure release chamber with the front end cap 3 with access to its variable vent 12 . As with the back membrane 11 , the front membrane 19 dilutes pneumatic pressures, provides an acoustic seal and maintains crisp, clear sound quality.
[0100] At the intersection 22 between the front end cap 3 and the ear horn 4 , a metal mesh disk can be placed, which is used to filter pitches according to the user's preference. Smaller mesh spacings of a typical rectilinear pattern preferentially pass higher pitched sounds and larger spacings, lower frequency sounds. Customized sound filter disks can have a mixture of spacing sizes and shapes not limited to rectilinear patterns that provide a more nuanced filtering function across the sound spectrum.
[0101] Not shown in FIG. 5 is the audio cable assembly 7 . The audio cable 7 terminates with a power-transferring tip. The tip has pressure-connection coils. The tip is inserted into the cable port 6 of the central control unit 2 and the coils are mated to grooves within the cable port 6 . The grooves and the pressure-connection coils place the tip firmly and stably in the correct position to allow the tip to transfer power to the speaker. The cable strain protection sleeve 8 is slipped over the cable and typically is located against the cable port 6 . The cable sleeve 8 is not fixed to the audio cable 7 but through the friction between the rubberized surface of the audio cable 7 and its own material, it maintains its location until the user moves it to a preferred position. The optional ear hangar wire 9 is a slim piece of rubber-coated metal that is wide enough to have a reasonable lifetime and long enough to form a comfortable and stable shape over most users' ears. The ear hangar 9 fits into the cable sleeve 8 and carries the audio cable 7 over the user's ear.
[0102] FIG. 6 shows the A 1 with an enhancement 23 that transforms it from a simple listening device to a piece of jewelry. The back and front end caps as well as the central control unit 2 can be formed of customized materials and colors to create a desired visual effect. The back end cap 1 can also be visually embellished with features such as different bell shapes, carvings, filigrees, and precious stones.
[0103] FIG. 7 shows the A 1 with signal connectivity options. In FIG. 7A , the audio cable 7 connects to the earbud via the screw-in cable connector 24 , which mates to a spring-plate contact to pass signal. The audio cable 7 connects to an audio device using a standard 3.5 mm headphone jack 25 . In FIG. 7B , audio signals are sent wirelessly to a Bluetooth receiver 26 on a cable. This cable connects to both earbuds in the same manner as 7 A but is free of physical connection to an audio source device. In FIG. 7C , the Bluetooth receiver is housed within one earbud and sends a stereo signal via FM to the other earbud. An optional earbud stabilizer 27 acts as an antenna that further stabilizes the Bluetooth signal and improves the possible range from the audio device. The signal connectivity options can identically be used with the second Ambrose Earbud embodiment, A 2 .
[0104] FIG. 8 demonstrates an example combined displacement-and-loudness-based digital compression upper limit spectrum (heavy, solid line) in comparison to equal loudness curves at 0, 40, 60, and 100 phons (data points). Here, the example upper limit is set at the minimum of 55 phons or 55 dB (or 600 times the air displacement at 1 kHz and 0 phon). Volumes are capped at 55 dB except in the mid-range where the perceived loudness would be too high in comparison.
[0105] FIG. 9 is the view of the fully assembled, closed Ambrose Earbud, secondary embodiment with directionality sensitivity of ambient sound, which will be referred to as A 2 . Many elements are visible. The open end cap 28 sits with a snap-fit connection on top of the top vent, exterior basket 29 , which has one of its top vent, exterior basket, vents 30 visible. The top vent, exterior basket 29 sits inside the top vent, interior basket 32 with a relative position (and thus venting status) controlled with the top vent, exterior basket, positioning handle 31 , which slides within the top vent, interior basket, positioning handle seat arc 34 . The top vent, interior basket 32 fits with a snap-fit connection inside the side vent, interior basket 40 , which is likewise fit within the side vent, exterior basket 43 . Three of the side vent, exterior basket, vents 44 are visible. The side vent, interior basket 40 snap-fit connects to the ear horn 45 , which is likewise fit to the ear tip 46 . The cable port 47 on the side of the side vent, exterior basket 43 is connected to the cable protector sleeve 50 through internal elements.
[0106] FIG. 10 demonstrates the adjustability of the top vents of the A 2 . In FIG. 10A , the top vents of the A 2 are open. The top vent, exterior basket, positioning handle 31 is set in the far right position. The top vent, exterior basket, vents 30 are aligned with the top vent, interior basket, vents 33 to provide access to the outside air. This maximizes the dampening of excess pneumatic pressures through the minimum impedance on the ADEL membrane 37 and allows the user to most clearly hear ambient sounds from a narrow cone of relative positions to the user. In FIG. 10B , the top vents of the A 2 are partially open. The handle 31 is set in the middle position. The top vent, exterior basket, vents 30 are partially aligned with the top vent, interior basket, vents 33 to provide medium access to the outside air. This provides an intermediate level of pneumatic pressure dampening and a reduced level of ambient sound from a narrow cone of a user's relative position relative to the open position. In FIG. 10C , the top vents of the A 2 are fully closed. The handle 31 is set in the far left position. The top vent, exterior basket, vents 30 are anti-aligned with the top vent, interior basket, vents 33 to provide no access to the outside air and maximum isolation from ambient sounds in the narrow position cone. The ADEL membrane 37 experiences high impedance and is in a lowered state of pressure damping.
[0107] FIG. 11 demonstrates the adjustability of the side vents of the A 2 , similar to that of the top vents. In FIG. 11A , the side vents of the A 2 are open. The side vent, exterior basket, vents 44 are aligned with the side vent, interior basket, vents 41 to provide access to the outside air. This maximizes the dampening of excess pneumatic pressures through the minimum impedance on the ADEL membrane 37 and allows the user to most clearly hear ambient sounds from a wide cone of relative positions to the user. In FIG. 11B , the side vents of the A 2 are partially open. The side vent, exterior basket, vents 44 are partially aligned with the side vent, interior basket, vents 41 to provide medium access to the outside air. This provides an intermediate level of pneumatic pressure dampening and a reduced level of ambient sound from a narrow cone of a user's relative position relative to the open position. In FIG. 11C , the side vents of the A 2 are fully closed. The side vent, exterior basket, vents 44 are anti-aligned with the 41 side vent, interior basket, vents 41 to provide no access to the outside air and maximum isolation from ambient sounds in the wide position cone. The ADEL membrane 37 experiences high impedance and is in a lowered state of pressure damping. The ADEL membrane 37 experiences the least overall impedance and can dampen the greatest amount of excess pneumatic pressures off the tympanic membrane when both the top and side vents are fully open and the opposite is true when both the top and side vents are fully closed.
[0108] FIG. 12 is an exploded view of the A 2 . Multiple transducers 35 (speakers and amplifiers) are used to maximize the fidelity of the sound going into the earbud. Each of the transducers 35 can focus on a narrow-band section of the frequency spectrum to produce higher quality sound than a single transducer that attempts to cover a full spectrum of sound. The transducers 35 are fitted onto the transducers seats 39 on the spacer and transducer positioner 38 . They are held in place by the transducer positioning couplers 36 . The ADEL membrane 37 and frame is snap-fitted into the spacer and transducer positioner 38 . The ADEL membrane 37 is placed between two circular frames and the three elements are firmly fixed through a press-fit. The ADEL membrane provides an acoustic seal for the ear canal, which prevents sound drop-out, particularly in the bass yet through its compliance, it dampens the energy of the pneumatic pressures associated with sound. The ADEL membrane is able to damp the most pressure (most compliant; experiences the least impedance) when the side opposite the sound pressure has access to the barometric air pressure. For A 2 , two sets of basket-shaped multi-vents are used to provide the user the ability to identify the direction of an ambient sound (360 degrees, narrow and wide cones of position) while using the A 2 for improved personal safety and communications. The top vent baskets are located above the transducers 35 . Anopen end cap 28 with a logo snap-fits into the top vent, exterior basket 29 . The pair similarly goes into the top vent, interior basket 32 , which is then snap-fitted above the side vent, interior basket 40 and into the side vent, exterior basket 43 . The side vent, interior basket 40 snap-fit connects to the ear horn 45 , which is likewise fit to the ear tip 46 . On the side of the side vent, exterior basket 43 is the cable port 47 through which the transducers 35 receive power. The side vent, interior basket 40 has a side vent, interior basket cable access sliding window. As the side vent, interior basket 40 is rotated relative to the side vent, exterior basket 43 between venting positions, the audio power cable pathway is not disrupted. The audio cable pressure-connector 48 fits inside the cable port 47 and the power-transferring cable tip 49 is snap-fitted inside of it. The cable protector sleeve 50 wraps around the power-transferring cable tip 49 and the end of the audio cable. The ear tip 46 snap-fits onto the end of the ear horn 45 , which in turn snap-fits into the bottom of the side vent, exterior basket 43 . The ear tip 46 fits into the user's ear such that a seal is completed.
[0109] FIG. 13A is the view of the fully assembled, closed Ambrose Tunable Impedance Matched Acoustic Transformer, third Ambrose Earbud embodiment to be used as a modification to In-Ear-Monitors, which will be referred to as A 3 . Most elements are visible. The Controller 51 is connected to the rest of the system through parts not visible in this view. The ambient vent 52 is pressure-fitted onto the top of the adjustable secondary eustachian tube 53 , which forms the main A 3 shape and contains the majority of its parts. The adjustable valve 54 is a flexible cylinder trapped between the ambient vent 52 and the membrane tensioner 55 . The membrane tensioner 55 has two sets of vents: the membrane tensioner, top vents 56 and the membrane tensioner, side vents 57 . It travels up and down the inside of the adjustable valve 54 according to the adjustments of the controller 51 with a fully extended position that makes it touch the ADEL membrane 58 . The membrane 58 is stretched across the ADEL membrane frame 60 and the pair is pressure-fitted into the end of the adjustable secondary eustachian tube 53 where it rests on the adjustable secondary eustachian tube, ADEL membrane seat 59 . 13 B demonstrates the scale of the A 3 . It is integrated into an In-Ear-Monitor and a user is adjusting the venting level by turning the controller 51 . The A 3 is placed in a tube that penetrates through the in-ear-monitor to the ear canal. The ambient vent 52 is flush with the exterior surface. The controller 51 is accessible to the user and the controller stem 61 , which connects the controller 51 to all the internal parts, is visible.
[0110] FIG. 14 demonstrates the venting adjustability of the A 3 in cross-sectional cut views. This view shows the controller 51 connected to the controller stem 61 , which ends in the controller stem base 62 . The base forms the center of the membrane tensioner 55 and the two parts are snap-fitted together. The adjustable valve 54 surrounds the controller stem 61 . In FIG. 14A , the A 3 is fully sealed to ambient sounds and air pressure. The controller 51 is rotated all the way outward, it has pulled the membrane tensioner 55 outward via the controller stem base 62 and the flexible material of the adjustable valve 54 is compressed to its maximum level such that it completely fills the radius of the adjustable secondary eustachian tube 53 . In FIG. 14B , the A 3 is mostly closed. The controller 51 is rotated partially inward, the membrane tensioner 55 is pushed partially inward, and the adjustable valve 54 is partially relaxed. In FIG. 14C , the A 3 is mostly open. The controller 51 is rotated further inward, the membrane tensioner 55 is pushed further inward, and the adjustable valve 54 is mostly relaxed. In FIG. 14D , the A 3 is fully open to ambient sounds and pressures. The controller 51 is rotated all the iway inward, the membrane tensioner 55 is pushed to its maximum position, and the adjustable valve 54 is fully relaxed. The membrane tensioner 55 is in contact with the ADEL membrane 58 , which now has less but still some flexibility in the presence of pneumatic sound pressures. In the intermediate positions of 14 B and 14 C, the maximum pneumatic pressure dampening will occur as the ADEL membrane 58 has maximum flexibility and real-time pressure changes in the adjustable secondary eustachian tube can be exhausted through the ambient vent 52 .
REFERENCED NUMERALS IN DRAWINGS
[0000]
1 . Back end cap
2 . Central control unit
3 . Front end cap
4 . Ear horn
5 . Ear tip
6 . Cable port
7 . Audio cable
8 . Cable strain protection sleeve (Not to scale)
9 . Optional ear hangar shaping wire (Not to scale)
10 . Vent channel on perimeter of central control unit
11 . Back flexible compliant membrane
12 . Variable vent channel in back end cap. (Identical vent channel exists in 3 . Front end cap, not shown)
13 . Back membrane end cap frame
14 . Back membrane gasket
15 . Back membrane to speaker frame and spacer
16 . Speaker front gasket
17 . Speaker front spacer
18 . Front membrane to speaker frame
19 . Front flexible compliant membrane
20 . Front membrane end cap frame
21 . Interior space of central control unit where speaker (not shown) sits
22 . Intersection of front end cap and ear horn where sound filter screen sits
23 . Decorative embellishment
24 . Screw-in cable connector
25 . Headphone jack
26 . Cross-earbud cable with Bluetooth fob
27 . Over-ear antenna and earbud stabilizer
28 . Open end cap with Logo
29 . Top vent, exterior basket
30 . Top vent, exterior basket, Vent (×3)
31 . Top vent, exterior basket, positioning handle
32 . Top vent, interior basket
33 . Top vent, interior basket, Vent (×3)
34 . Top vent, interior basket, positioning handle seat arc
35 . Transducers (speakers and amplifiers; ×6)
36 . Transducer positioning couplers (×6)
37 . Flexible compliant membrane and frame
38 . Spacer and Transducer positioner
39 . Transducer seat (×6)
40 . Side vent, interior basket
41 . Side vent, interior basket, Vent (×5)
42 . Side vent, interior basket, cable access sliding window
43 . Side vent, exterior basket
44 . Side vent, exterior basket, Vent (×5)
45 . Ear horn
46 . Ear tip
47 . Cable port
48 . Cable pressure connector
49 . Power-transferring cable tip
50 . Cable protector sleeve
51 . Controller
52 . Ambient Vent
53 . Adjustable Secondary Eustachian Tube
54 . Adjustable Valve
55 . Membrane Tensioner
56 . Membrane Tensioner, top vents
57 . Membrane Tensioner, side vents
58 . Flexible compliant Membrane
59 . Adjustable Secondary Eustachian Tube, ADEL Membrane Seat
60 . ADEL Membrane Frame
61 . Controller Stem
62 . Controller Stem Base
Operation of the Invention
[0173] All embodiments of the Ambrose Earbud are designed to be fully modular. Intersection edges have a ridge and a groove or are smoothly pressure-fitted. Adjacent parts are fitted together by aligning them and manually applying compression. The ridges of the two parts push up and over each other and land in the opposing part's groove. This style of part pairing provides simple and adhesive-free assembly as well as the ability for users and retail customizers to service and exchange parts without the need to purchase a new earbud. The snap-together connection is stable under typical use and snaps apart with reverse pressure.
[0174] During the manufacturer's assembly of the A 1 , employees prepare each end cap, stack the central elements and finish by connecting the end cap sections to the central section. The back membrane is placed within the back membrane frame and the back membrane gasket is pressed over the membrane, holding it fixed in place. The back membrane frame assembly is pressed into the back end cap. Likewise, the front membrane is placed across its designated orifice within the front membrane frame and the front membrane gasket is pressed over top, fixing it in place. The pins of the front membrane frame are placed and pressed into a set of holes on the front end cap, ensuring proper alignment and seal between the front membrane and the front end cap vent channel. The ear horn is pressed into the front end cap and the ear tip onto the ear horn. The speaker is placed within the back membrane-to-speaker frame and spacer and positioned so that the speaker's power connector element is aligned with the notch in the frame. The back membrane-to-speaker frame and spacer is placed inside the central control unit so that the notch is aligned with the cable port. The audio cable tip is passed through the cable port and situated so that the tip's pressure pins rest in their designated grooves in the cable port for proper mating with the speaker. The speaker front gasket is placed within the central control unit on the far side of the notch, after which, the speaker front spacer follows suit. The back end cap section is snapped onto the central control unit and likewise, the front end cap section.
[0175] During the manufacturer's assembly of the A 2 , employees begin with the side vent, exterior basket and fill it with each consecutive element moving outward from the ear (side vent, interior basket; ADEL membrane; transducers and their positioners; the top venting baskets; and the logo endcap). The cable connection assembly is then completed and finally the ear horn and tip.
[0176] During the manufacturer's assembly of the A 3 , employees begin with the controller and its stem. The ambient vent is screwed onto the stem and then the adjustable valve tube is placed around the stem. The controller stem base is snap-fitted into the center of the membrane tensioner and the pair is screwed onto the stem below the adjustable valve. The adjustable secondary Eustachian tube is coaxially placed around the stem and pressure-fitted onto the ambient vent. The ADEL membrane is stretched across the membrane frame and is held firmly in place by the pressure-fit between the membrane frame and the adjustable secondary Eustachian tube.
[0177] The user selects their preferred audio connectivity method: via audio cable, cabled Bluetooth, or fully wireless Bluetooth with or without the antenna stabilizer option. The audio cable, Bluetooth cable, and antenna stabilizer each are screwed into the cable jack of the earbud. At the terminus of the cable jack, there is a spring-plate connector across which signal from either cable or antenna is passed. The headphone jack is physically inserted into the user's audio device while the Bluetooth cable receiver or in-earbud receiver is wirelessly paired to the audio device. The user curls and crimps the antenna over their ear.
[0178] The user fits either Ambrose Earbud to their own ear geometry and preferred wearing method. The ear horn is first placed into the ear canal and rotated to the most comfortable direction. The front end cap of the A 1 is then rotated about with the ear horn maintained in same relative direction to the ear canal to find the appropriate height of entry into the ear canal. With the simpler geometry of the A 2 relative to the human ear, the user chooses just the relative angle of the audio cable, if used, to the ear horn. The user then chooses whether they prefer the cable to hang downward or to follow the optional ear hangar over the ear. A user determines through the exchange of ear horn models (described below) and trial and error, which set of ear horn length, curvature, direction and initial height creates the most comfortable fit for their ears.
[0179] For the standard earbud use-case of listening to music with no concerns of environmental sounds, the variable vents are open to the barometric air pressure (the A 1 end caps are rotated so that the preferred fit is maintained) providing the greatest freedom of movement to the speaker as well as pneumatic pressure dilution away from the tympanic membrane. Venting variations can be used to process the sound according to the user's preference with the A 1 . The front vent is rotated to a less open to fully closed position to highlight bass sounds and in reverse, a less open back vent highlights mid to high pitches. The spectral processing of the A 2 is conducted through programming of the set of transducers. Often, a user is expected to desire a nuanced, intermediate combination of sound isolation while actively listening through their Ambrose Earbuds. A user may be in a loud environment, such as on an airplane or in a noisy crowd, and want more isolation for their music or telephone conversation. To maintain the noiseless spectral characteristics of their audio source, both vents are reduced the same amount.
[0180] The Ambrose Earbud acts alternatively as a variable hearing protector. Maximum hearing protection from loud environmental sounds as well as internal occlusion effects is achieved with the speaker powered off. While maintaining the preferred fit, the user rotates the A 1 end caps so that the variable vents are aligned through the vent channels on the central control unit to each other or by anti-aligning both sets of the A 2 venting baskets. The user rotates the vents to partially open states to acquire partial isolation when they want to hear an external sound at a reduced level, such as while enjoying a rock concert, without sacrificing sound quality. As with an active speaker sound source, bass environmental sounds are highlighted by rotating the A 1 front end cap to a reduced venting position and mid to high sounds, the back vent. Another alternative embodiment of the Ambrose Earbud is as a variable hearing protection device only. This embodiment would have no cable port or speaker yet would operate through manipulation of variable vents in a manner identical to the passive Ambrose Earbud acting as a hearing protector.
[0181] A user or retail customizer can service or exchange parts of either Ambrose Earbud. The earbud is opened and its internal parts accessed by placing finger tips or a small, strong object such as a penny between parts and exerting pressure against in an external direction. The earbud snaps open and the internal elements can be accessed. Thinner items such as finger nails or a miniature screwdriver are inserted between interior parts to similarly snap them apart. Worn parts are removed, replacements inserted and the earbud is snapped back together by realigning each element. Standard elements are replaced by preferred elements such as higher quality speakers; a denser and conical-bell shaped back A 1 end cap for a specific resonance effect; a pair of precious inlayed metal end caps designed by renowned jeweler to highlight a special event; a longer and more curved ear horn for improved fit; etc. A sound filter is not standard but can be snapped into the ear horn during servicing. Once the servicing with all replacements or exchanges made is complete, the user re-assembles the parts and closes the earbud in the same manner as the original manufacturer.
[0182] A performer using the Ambrose Tunable Impedance-Matching Acoustic Transformer (A 3 ) rotates the controller outward to reduce and inward to increase the amount of ambient sounds that they can hear. At an intermediate position, they hear some amount of their environmental sounds that is less than available with a fully open ear. The ADEL membrane experiences the least impedance as it is unrestrained by the membrane tensioner and the adjustable secondary Eustachian tube is vented to barometric pressure. Excess pneumatic pressures from sound are readily damped. At the innermost position, the membrane tensioner is in contact with the ADEL membrane and causes its impedance to increase. The membrane's impedance is proportional to the amount of tension placed upon it and has spectral properties. A performer can choose a small or large amount of tension to acquire their desired frequency processing affect. At the outermost position, the adjustable secondary Eustachian tube is isolated from ambient sounds and barometric pressure. The ADEL membrane is not physically tensioned yet it still experiences a high impedance since pressure changes cannot be vented. As with the tensioned membrane, when the adjustable valve is near its maximum diameter, frequency changes can be heard by the performer and controlled to their desired properties. When the ADEL membrane is at its maximum impedance, whether through a sealed vent or through tensioning, the speaker necessarily also experiences maximum impedance. Since pneumatic pressures are not damped via the membrane, they impinge back into the sealed ear canal and impact both the tympanic membrane and the speaker. The reverse is also true. The speaker experiences minimum impedance when the ADEL membrane is most free to flex and dampen the pneumatic pressures of sound.
[0183] At music performances with noise-reducing broadcast systems, music is performed on stage with no amplification and microphones pick up the sounds. Attendees sign into the broadcast system with their music devices and select either a location-based delay using methods such as GPS, Wi-Fi or seat numbers or a sound-synchronization method that employs their own device's microphone to detect the live music and calculate a timing offset for the broadcast transmission. The system broadcasts the music to the attendee's audio device delayed by their distance from the performers and modulated by the geometry of the venue in the attendee's instantaneous location. The broadcast signal is passed to the attendee's Ambrose Earbuds, which are adjusted according to the attendee's preferences and as indicated above. Infrasounds, lights, smoke, and other special effects are manipulated to generate energy in the audience and create a unique listening event experience. Performers also sign into the broadcast system and monitor the sound the audience hears by choosing the broadcasts for specific locations across the venue.
[0184] A displacement-and-loudness-based digital compression algorithm is integrated into audio processing software such as a music application on a smartphone. The user chooses whether or not to have the digital compression on and, if on, which type of ear tip they are using as each ear tip type has a corresponding upper limit on air displacement from sound before hearing damage can occur. Among ear tips that seal the ear canal, such as foam plugs or mushroom-cap styles, the Ambrose Earbud negates the greatest amount of damage yet requires the least amount of sound volume for a quality listening experience. The user also selects the minimum sound volume across the spectrum and therefore, creates their own customized dynamic range. As each note of music passes through the audio processing software, the digital compression algorithm raises a too quiet pitch to the user's minimum and reduces an overly loud pitch to the maximum volume according to how much air is displaced at its' frequency and the energy dilution of the user's ear tip. The musical note is then passed from the audio processing software to the listener's ear.
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An improved earbud design providing for full modularity; improved and variable hearing protection, sound quality, comfort, fit, aesthetics, and signal connectivity; and the ability to maintain environmental sound directionality comprised of a multitude of new features with variable vents and membranes which dilute the harmful pneumatic effects of sound while improving its acoustic quality. A location-based transmission system provides event attendees to mix live sound with streamed sound through Ambrose Earbuds for reduced hearing risk and no quality detriments due to timing gaps, occlusion or ear tip spectral broadening, and enables noise pollution-free musical performances. A displacement-based digital compression algorithm caps maximum output air displacement as well as sound pressure level. Thus, an earbud is provided that through adjustments and modularity can act as a personal listening device, a hearing protection device and as a personal aesthetic statement with customized fit and comfort.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending International Application No. PCT/DE99/02412, filed August 2, 1999, which designated the United States.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a method for manufacturing integrated circuits and a semiconductor wafer that can be used in the method according to the invention.
[0004] In the prior art, fabrication methods for manufacturing integrated circuits, in particular chip-size packages from semiconductor wafers are known in which, in a first step, circuit structures for a plurality of integrated circuits are manufactured on an active side of a semiconductor wafer. Then, the integrated circuits are divided up into so-called chips by sawing the semiconductor wafer into individual pieces at the edge areas of the integrated circuits. Contact is made with the chips in each case at so-called interposers that may be of a rigid or a flexible configuration. It is also conceivable to make contact with a chip on a so-called lead frame. The contact can be made with different contacting methods, for example with a wire contacting method, with a flip-chip contacting method or with a TAB contacting method.
SUMMARY OF THE INVENTION
[0005] It is accordingly an object of the invention to provide a method for manufacturing integrated circuits and a semiconductor wafer which has integrated circuits which overcomes the above-mentioned disadvantages of the prior art methods of this general type, in which a simplified method for manufacturing integrated circuits is described.
[0006] With the foregoing and other objects in view there is provided, in accordance with the invention, a manufacturing method for forming integrated circuits. The method includes the steps of:
[0007] providing a semiconductor wafer having an active side with circuit structures for forming at least two integrated circuits;
[0008] providing at least one electrically insulating intermediate layer;
[0009] applying at least one electrically conductive conductor foil to the electrically insulating intermediate layer;
[0010] forming at least one through-opening in the electrically insulating intermediate layer, the at least one through-opening extends from an underside of the electrically conductive conductor foil to an underside of the electrically insulating intermediate layer;
[0011] applying the least one electrically insulating intermediate layer having the electrically conductive conductor foil to the active side of the semiconductor wafer;
[0012] forming conductor tracks from the electrically conductive conductor foil; and
[0013] dividing the semiconductor wafer into individual integrated circuits.
[0014] The method according to the invention ensures a simple way to manufacture integrated circuits. A relatively thick organic dielectric layer is first provided for compensating for expansion. The final conductor structure with large conductor cross sections is produced only at the wafer level of the semiconductor wafer. The basic principle is to laminate a copper foil onto the semiconductor wafer, form a contact between the copper foil and the chip terminals or the connecting contacts of the integrated circuits and only then implement rewiring using photolithographic and etching technology.
[0015] The resin cover for a solder stop masking of the terminals can then be provided. Finally, the application of solder balls and the cutting up of the semiconductor wafer into individual packages can be carried out, for example by sawing. Generally, in order to give the semiconductor chip a particularly level surface it is possible to accompany the application of the copper foil laminate with a suitable corresponding coating on the passive reverse side of the chip.
[0016] In a development of the invention, the step of applying the intermediate layer to at least one electrically conductive conductor foil is carried out before the step of applying the intermediate layer to the active side of the semiconductor wafer. This embodiment of the method according to the invention serves as a basis for variants in which the intermediate layer is completely manufactured together with the conductor foil before application to the semiconductor wafer. In these embodiments of the method according to the invention it is particularly advantageous that manufacturing steps which are carried out on the intermediate layer and on the conductor foil do not affect the integrated circuits on the semiconductor wafer.
[0017] Before the step of applying the intermediate layer to the active side of the semiconductor wafer it is possible to provide the step of making at least one through-opening in the intermediate layer, the through-opening being embodied in such a way that it extends from an underside of the conductor foil to the underside of the intermediate layer. Then, contact can be made with the conductor foil through the through-opening. The through-opening is preferably made with a laser method, which enables precise through-openings to be achieved.
[0018] In order to make contact with the conductor foil through the intermediate layer it is possible to introduce a conductive filler and connecting material such as a solder material into the through-opening, specifically in particular by an electrodeposition method. This ensures that the semiconductor wafer according to the invention is manufactured in a particularly cost-effective and reliable way.
[0019] The step of heating the solder material in the through-opening may be provided in order to make contact between the conductor foil and the contact points on the integrated circuits on the semiconductor wafer, and may specifically be provided after the application of the intermediate layer to the active side of the semiconductor wafer. When the solder material in the through-opening is heated, the solder material is melted and forms a conductive connection with the contact points provided on the semiconductor wafer. Such heating is preferably carried out at points on the conductor foil in the vicinity of the through-opening so that the effect of the heat on the semiconductor wafer according to the invention is particularly low.
[0020] In a modification of the embodiments of the method according to the invention given above it is also possible to introduce a conductive adhesive as the conductive filler and connecting material into the through-opening, specifically in particular by a doctor blade method. The provision of the conductive adhesive in the through-openings favors large-scale series fabrication of the semiconductor wafer according to the invention. Here, the step of curing the conductive adhesive in the through-openings may be provided after the step of applying the intermediate layer to the active side of the semiconductor wafer, and may specifically be provided in such a way that the conductive adhesive forms a conductive connection both with the conductor foil and with contact points provided on the semiconductor wafer. A particularly favorable connection between the semiconductor wafer, the intermediate layer and the conductor foil is obtained if the step of applying the intermediate layer to the active side of the semiconductor wafer is carried out with a lamination method, in particular with the application of pressure and heat.
[0021] With the foregoing and other objects in view there is further provided, in accordance with the invention, a second method for manufacturing integrated circuits. The method includes the steps of:
[0022] providing a semiconductor wafer having an active side with circuit structures for at least two integrated circuits;
[0023] applying at least one electrically insulating intermediate layer to the active side of the semiconductor wafer;
[0024] applying a solder material to contact points provided on the semiconductor wafer by an electro-deposition method or an electroless deposition;
[0025] applying at least one electrically conductive conductor foil to the electrically insulating intermediate layer, an application of the electrically conductive conductor foil to the electrically insulating intermediate layer being provided after an application of the electrically insulating intermediate layer to the active side of the semiconductor wafer;
[0026] forming conductor tracks from the electrically conductive conductor foil; and
[0027] dividing the semiconductor wafer into individual integrated circuits.
[0028] A fundamentally different group of manufacturing methods for semiconductor wafers according to the invention provides that the step of applying the conductor foil to the intermediate layer is not carried out before but rather after the step of applying the intermediate layer to the active side of the semiconductor wafer. In these embodiments of the method according to the invention it is particularly advantageous that the handling of the conductor foil together with the intermediate layer is simplified because together they form one thin layer and are moved together.
[0029] In this context there is in particular provision that the intermediate layer is manufactured on the active side of the semiconductor wafer using a printing method. To do this, it is possible, for example, to apply adhesive to the active side of the semiconductor wafer.
[0030] If a solder material has been applied to the contact points provided on the semiconductor wafer, it is melted by heating after the application of the conductor foil to the intermediate layer, with the result that a conductive connection is produced between areas of the conductor foil and the contact points provided on the semiconductor wafer.
[0031] The methods explained above give rise to the semiconductor wafer according to the invention on which the insulating intermediate layer is formed, and the conductive conductor foil is formed on top of it. Subsequently, the conductor tracks are formed in the conductor foil, specifically in particular with an etching method by etching away areas of the conductor foil. To do this, conventional techniques may be used, it being possible in particular to provide the step of coating the conductor foil with etching resist and forming the conductor tracks using photolithographic steps.
[0032] Finally, the step of performing solder stop masking of ball land areas and the step of producing solder balls at predefined points on the conductor foil is carried out, which simplifies the later formation of contacts with the integrated circuits provided on the semiconductor wafer according to the invention.
[0033] The semiconductor wafer according to the invention is characterized by an active side with circuit structures, at least one electrically insulating intermediate layer and at least one electrically conductive conductor foil with conductor tracks being provided on the active side. A conductive filler and connecting material are provided here between the contact points on the semiconductor wafer and areas of the conductor foil.
[0034] The finished semiconductor wafer according to the invention is sawn into individual integrated circuits. This is carried out with high-speed cutting disks that are equipped with diamond particles. The diamond particles are very thin and are clamped into a mandrel in such a way that they protrude by a small amount. To do this, a plate is moved over the semiconductor wafer with numerical control and precise clocking in the grid spacing of the integrated circuits so that the integrated circuits are separated. The semiconductor wafer is previously bonded onto a foil so that the integrated circuits remain in their order during the sawing process. This foil is also sawn as the semiconductor wafer is sawn.
[0035] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0036] Although the invention is illustrated and described herein as embodied in a method for manufacturing integrated circuits and a semiconductor wafer which has integrated circuits, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0037] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIGS. 1 - 7 are diagrammatic, sectional views of manufacturing steps for producing a first semiconductor wafer according to the invention;
[0039] FIGS. 8 - 13 are sectional views of the manufacturing steps for producing a second semiconductor wafer; and
[0040] FIGS. 14 - 18 are sectional views of the manufacturing steps for producing a third semiconductor wafer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown in cross section layers of a first semiconductor wafer 1 according to the invention.
[0042] [0042]FIG. 1 shows a printed circuit board 2 , which is divided into an electrically insulating intermediate layer 3 and into an electrically conductive copper coating 4 which is applied over a surface of the electrical intermediate layer 3 .
[0043] [0043]FIG. 1 shows the printed circuit board 2 in its basic state, that is to say a B stage material coated with copper or a carrier material coated with an adhesive.
[0044] [0044]FIG. 2 illustrates the first manufacturing step of the semiconductor wafer 1 according to the invention. In this step, through-openings 5 are made in the intermediate layer 3 of the printed circuit board 2 and extend from the copper coating 4 to an underside of the intermediate layer 3 . A laser method is preferably used for this.
[0045] [0045]FIG. 3 illustrates a further manufacturing step for manufacturing the semiconductor wafer 1 . In this step, a solder material 6 in the form of tin is electro-deposited in the through-openings 5 , the solder material 6 being present on the underside of the copper coating 4 .
[0046] [0046]FIG. 4 illustrates a further manufacturing step for manufacturing the semiconductor wafer 1 . Here, the printed circuit board 2 in FIG. 3 is applied to a semiconductor wafer 7 that has integrated circuits 30 on its upper side. The connection of the printed circuit board 2 to the semiconductor wafer 7 is manufactured by a lamination process. The printed circuit board 2 is laminated here onto the semiconductor wafer 7 in such a way that the through-openings 5 come to rest precisely over Ni/Au bumps 31 being contact points 31 on the integrated circuits 30 on the semiconductor wafer 7 .
[0047] [0047]FIG. 5 illustrates a further manufacturing step during the manufacture of the semiconductor wafer 1 according to the invention. By heating points on an upper side of the printed circuit board 2 in areas around the through-openings 5 , the solder material 6 is melted using a laser beam 8 so that it forms an intimate connection with the wettable terminals (not illustrated in this view), for example the Ni/Au bumps and with corresponding areas on the copper coating 4 , and forms an electrically conductive connection between the copper coating 4 and contact areas on the integrated circuits 30 on the semiconductor wafer 7 .
[0048] [0048]FIG. 6 shows a further step during the manufacture of the semiconductor wafer 1 according to the invention. In this step, conductor tracks 9 , which permit contact to be made as desired with the through-openings 5 , are formed in the copper coating 4 using a photolithographic technique and an etching technique.
[0049] [0049]FIG. 7 illustrates a further manufacturing step of the semiconductor wafer 1 according to the invention. In this step, the conductor tracks 9 are provided with solder stop masking (not shown in this view), on which so-called balls 10 are formed on the conductor tracks 9 . In a manufacturing step (not illustrated here in more detail), the semiconductor wafer 1 is subsequently sawn into so-called individual chips.
[0050] FIGS. 8 - 13 illustrate the manufacture of a second semiconductor wafer 11 according to the invention. The manufacture of the second semiconductor wafer 11 corresponds essentially to the manufacture of the first semiconductor wafer 1 . For this reason, identical parts are provided with the same reference numbers.
[0051] In contrast to the first semiconductor wafer 1 in FIGS. 1 - 7 , in the second semiconductor wafer 11 in the manufacturing step according to FIG. 10, a conductive adhesive 12 is introduced into the through-openings 5 by a doctor blade method. During the lamination of the printed circuit board 2 onto the semiconductor wafer 7 , the conductive adhesive 12 introduced into the through-openings 5 is simultaneously cured.
[0052] All the other manufacturing steps for manufacturing the semiconductor wafer 11 correspond essentially to the manufacturing steps for the semiconductor wafer 1 .
[0053] FIGS. 14 - 18 illustrate the manufacture of a third semiconductor wafer 20 according to the invention. visible in this view) are formed. Contact areas are provided with layers of Ni/Au (not visible in this view), on which a solder material 24 is applied.
[0054] In the manufacturing step illustrated in FIG. 15, a copper coating 25 is applied to an upper surface of the intermediate layer 22 and to the surface of the solder material 24 .
[0055] Virtual through-openings that are filled with the solder material 24 are made in junction areas to the intermediate layer 22 by the solder material 24 .
[0056] In the manufacturing step illustrated in FIG. 16, the solder material 24 is melted by heating points using laser beams 26 so that a conductive connection is produced between the copper coating 25 and the contact areas (not visible in this view) of the integrated circuits provided on the semiconductor wafer 21 .
[0057] In the manufacturing steps illustrated in FIGS. 17 and 18, the conductor tracks 9 and the balls 10 are formed on the third semiconductor wafer 20 , the third semiconductor wafer 20 corresponding to the first semiconductor wafer 1 according to the invention and to the second semiconductor wafer 20 according to the invention in FIGS. 1 - 13 . For this reason, identical parts are provided with the same reference numbers.
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A method for manufacturing integrated circuits is described. A semiconductor wafer having an active side with circuit structures is provided. An electrically insulating intermediate layer and an electrically conductive conductor foil are applied to the active side. Conductor tracks with terminal balls are formed with a relatively large spacing pattern in the conductor foil. The semiconductor wafer is subsequently divided up into integrated circuits.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2003-340131, filed on Sep. 30, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device and a method for testing the same.
2. Related Background Art
The actuation of a semiconductor memory (for example, to read out therefrom or write therein data) requires various potentials. To supply all the potentials from outside, many kinds of external power supplies will be needed. This inevitably calls for a large and complex system that effects the operation of the semiconductor memory. Besides, the necessity for mounting many external power supply terminals on the semiconductor chip increases the chip area and the package size accordingly.
To cope with this, it is customary in the art to supply power from a single power source to the semiconductor chip and generate therein potentials necessary for its operation (which potentials will hereinafter be referred to also as internal potentials). The internal potentials of various levels are each generated based on a potential (hereinafter referred to also as a reference potential) obtained by dividing the potential of the external power supply.
Generally, the reference potential may sometimes deviate from a design value due to stresses applied to the semiconductor wafer during the semiconductor manufacturing process. FIG. 14 is a diagram showing a conventional semiconductor device test procedure. Semiconductor elements formed on the semiconductor wafers in the semiconductor manufacturing process are tested for each die in a D/S (Die/Sort) step. At this time, the reference potential is also measured (S 1 ). If a deviation of the reference potential from the design value is found, the reference potential is trimmed to be close to the design value (S 2 ). This is done by physically cutting a wiring or wirings on the semiconductor wafer through laser irradiation. A description is given below of a conventional reference potential generator for trimming the reference potential.
FIG. 15 is a block diagram of a conventional reference potential generator 500 that generates a reference potential VBGR. Data decision circuits 540 - 0 to 540 - 2 , which form part of the reference potential generator 500 , are each configured as shown in FIG. 16 . Each data decision circuit 540 has a fuse 541 . Depending on whether or not the fuse 541 in step S 2 , the data decision circuits 540 - 0 to 540 - 2 output high- or low-level 1-bit data as signals SELECT 0 to SELECT 2 .
Referring back to FIG. 15 , data transfer circuits 530 - 0 to 530 - 2 respectively transfer the signals SELECT 0 to SELECT 2 to a decode circuit 520 . The data transfer circuits 530 - 0 to 530 - 2 are also capable of transferring test mode signals TMFUSEDIS to the decode circuit 520 instead of sending thereto the signals SELECT 0 to SELECT 2 .
FIG. 17 shows the configuration of the decode circuit 520 , which receives the signals SELECT 0 to SELECT 2 or TMFUSEDIS as 3-bit digital data composed of signals PRETMBGR 0 to PRETMBGR 2 . Based on the digital data it receives, the decode circuit 520 makes any one of signals TMBGR 0 to TMBGR 4 high-level and sends it to a reference potential selection circuit 510 . FIG. 5 shows the relationships between the signals PRETMBGR 0 to PRETMBGR 2 and the signals TMBGR 0 to TMBGR 4 . For example, the decode circuit 520 makes the signal TMBGR 1 high-level by making the signal PRETMBGR 0 low-level and the signals PRETMBGR 1 and PRETMBGR 2 high-level.
FIG. 18 shows the configuration of the reference potential selection circuit 510 , which divides the power supply voltage by resistors R 1 and R 2 to generate a plurality of different potentials. Based on that one of the signals TMBGR 0 to TMBGR 4 which is sent thereto, the reference potential selection circuit 510 selects any one of potentials BGR to BGR 4 , and outputs the selected potential as the reference potential VBGR. For example, when the signal TMBGR 1 is high-level, a switch SW 1 operates, and the reference potential selection circuit 510 outputs the potential BGR 1 as the reference potential VBGR.
In the test mode, the decode circuit 520 receives the test mode signals TMFUSEDIS as digital data, and outputs the signals TMBGR 0 to TMBGR 4 based on the test mode signals. The reference potential selection circuit 510 responds to the signals TMBGR 0 to TMBGR 4 to output a preset default potential (hereinafter referred to as a standard potential) as the reference potential VBGR. For example, when the potential BGR 2 is the standard potential, the signal TMFUSEDIS is preset so that the reference potential selection circuit 510 selects the potential BGR 2 .
Referring back to FIG. 14 , trimming of the reference potential VBGR in step S 2 is followed by a final semiconductor test of the semiconductor wafer (S 3 ), which is thereafter divided into individual semiconductor chips and packaged in an assembling step (S 4 ) and in a packaging step (S 5 ), respectively. Following this, the semiconductor chips undergo a reliability test (S 6 ) and a packaging final test (S 7 ), and are shipped as products.
One possible cause for a semiconductor chip to fail the reliable test (S 6 ) is a deviation of the reference potential VBGR from a design value. The reason for this is that the reference potential VBGR, though adjusted to the design value in step S 2 , shifts again due to stresses applied to the chip in the reliability test. Since no trimming is possible in the reliable test (S 6 ), however, the semiconductor chip decided as a reject is discarded.
In the D/S step 12 , trimming is carried out (S 2 ) on the assumption that the resistors R 1 and R 2 in FIG. 18 have their design values. Accordingly, the reference potential VBGR does not always become close to the design value, but in some cases it further deviates from the design value.
In the prior art, since the reference potential VBGR measuring step (S 1 ) and the fuse blowing step ( 2 ) are separate from each other, an exact value of the trimmed reference potential VBGR cannot be known prior to the fuse blowing step.
To obviate the above-mentioned defects of the prior art, there is a demand for a semiconductor device and its testing method that permits re-trimming or readjustment of the reference potential in the reliability test for each semiconductor chip.
Also, there is a demand for a semiconductor device and its testing method that permits the selection of a reference potential closest to its design value in the test of semiconductor elements for each die and in the adjustment of the reference potential.
SUMMARY OF THE INVENTION
A semiconductor device according to an embodiment of the invention that generates a desired internal power supply by using, as a reference potential, a potential obtained by adjusting a preset standard potential, the semiconductor device comprises a reference potential selection circuit selecting said reference potential on the basis of digital data from among a plurality of potentials of different levels which are obtained by dividing a power supply voltage, and outputting said reference potential in place of said standard potential; a first decision circuit deciding bits of said digital data; a second decision circuit deciding the bits of said digital data, separately from said first decision circuit; and a data transfer circuit transferring to said reference potential selection circuit said digital data which is decided by either one of said first and second decision circuits.
A method for testing a semiconductor device according to an embodiment of the invention that includes: a reference potential selection circuit selecting a reference potential on the basis of digital data from among a plurality of potentials of different levels which are obtained by dividing a power supply voltage, and outputting said reference potential in place of a standard potential preset by default so as to generate a desired internal power supply; a first decision circuit deciding the value of said digital data; a second decision circuit deciding the value of said digital data separately from said first decision circuit; a test data input portion tentatively inputting various pieces of digital data of different values from output; and a data transfer circuit transferring digital data which is fed thereto from any one of said first decision circuit, said second decision circuit and said test data input portion to said reference potential selection circuit; the method comprising:
transferring said various pieces of digital data of different levels from said test data input portion to said reference potential selection circuit by said data transfer circuit, and measuring reference potentials on the basis of said various pieces of digital data of different levels, respectively; and setting first digital data in said first decision circuit, said first digital data generating first one of said reference potentials which is optimum for the generation of said desired internal power supply.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a reference potential generator 100 according to a first embodiment of the present invention;
FIG. 2 is a circuit diagram showing the configuration of a data decision circuit 40 a - 0 ;
FIG. 3 is a timing chart showing the operation of a data decision circuit 40 a - 0 ;
FIG. 4 is a circuit diagram showing the configuration of a data selection circuit 50 ;
FIG. 5 is a table showing the relationships between signals PRETMBGR 0 to PRETMBGR 2 and signals TMBGR 0 to TMBGR 4 ;
FIG. 6 is a circuit diagram of a data transfer circuit 30 - 0 ;
FIG. 7 is a conceptual diagram of testing a semiconductor device which comprises the reference potential generator 100 ;
FIG. 8 is a flowchart of the procedure for testing the semiconductor device which comprises the reference potential generator 100 ;
FIG. 9 is a block diagram of a reference potential generator 200 according to a second embodiment of the present invention;
FIG. 10 is a circuit diagram of a standard data selection circuit 52 ;
FIG. 11 is a circuit diagram of a standard data transfer circuit 34 ;
FIG. 12 is a circuit diagram of a data selection circuit 54 ;
FIG. 13 is a circuit diagram of a data transfer circuit 32 - 0 ;
FIG. 14 is a diagram showing a conventional semiconductor device test procedure;
FIG. 15 is a block diagram of a conventional reference potential generator 500 that generates a reference potential VBGR;
FIG. 16 is a circuit diagram showing the configuration of a data decision circuit 540 - 0 to 540 - 2 ;
FIG. 17 shows the configuration of a decode circuit 520 ; and
FIG. 18 shows the configuration of the reference potential selection circuit 510 .
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention are described below with reference to the accompanying drawings. However, the invention is not limited by the embodiments.
A reference potential generator according to the present invention includes a plurality of data decision circuits, and is capable of supplying a reference potential selection circuit with digital data decided by one of the data decision circuits in place of digital data decided by the other. This permits readjustment of the reference potential in the reliability test. The reference potential generator has a test data input unit, and is capable of temporarily transferring digital data of various values to the reference potential selection circuit in place of the digital data decided by the data decision circuits. This ensures adjustment of the reference potential to bring it closer to the design value.
(First Embodiment)
FIG. 1 is a block diagram of a reference potential generator 100 according to a first embodiment of the present invention. The reference potential generator 100 includes: a reference potential selector circuit 10 ; decode circuit 20 ; data transfer circuits 30 - 0 to 30 - 2 ; data decision circuits 40 a - 0 to 40 a - 2 ; data decision circuits 40 b - 0 to 40 b - 2 ; an input data selection circuit 50 ; and a standard data decision circuit 60 . The reference potential selection circuit 10 and the decode circuit 20 may have the same configurations as shown in FIGS. 18 and 17 , respectively.
The data decision circuits 40 a - 0 to 40 a - 2 are used in the D/S step in FIG. 7 , whereas the data decision circuits 40 b - 0 to 40 b - 2 are used in the reliability test. The standard data decision circuit 60 is used when a standard potential is selected in the reliability test.
The reference potential generator 100 has an input part that temporarily inputs signals TMFUSESEL 0 to TMFUSESEL 2 and a signal TMFUSEDIS from outside in the test mode. These signals are used in the test mode, but on power-off, they are stopped.
FIG. 2 is a circuit diagram showing the configuration of the data decision circuit 40 a - 0 . The data decision circuits 40 a - 1 to 40 a - 2 and 40 b - 0 to 40 b - 2 have the same configuration as that of the data decision circuit 40 a - 0 .
FIG. 3 is a timing chart showing the operation of the data decision circuit 40 a - 0 . The other data decision circuits 40 a - 1 to 40 a - 2 and 40 b - 0 to 40 b - 2 operate in the same manner as does the data decision circuit 40 a - 0 . With reference to FIGS. 2 and 3 , the configuration and the operation of the data decision circuit 40 a - 0 are described below.
The data decision circuit 40 a - 0 has a fuse E-Fuse, which can electrically be treated unlike a fuse called an L-Fuse which is cut by a laser. The fuse E-Fuse is nonconducting when untreated and conducts when treated.
A description is given first of the operation of the data decision circuit 40 a - 0 when the fuse E-Fuse is not blown, that is, when it is nonconducting without being electrically treated. In FIG. 3 , the operation is indicated by “E-Fuse not Blow.”
On power-up at time t1, gate potentials FPUP and FPUN both are in low. At this time, since a transistor Trp 10 turns ON and a transistor Trn 10 turns OFF, the potential at a node N 10 goes high by the power supply voltage VDD.
At time t2, the gate potential FPUP goes high. As a result, the transistor Trn 10 turns OFF, but since the potential at the node N 10 remains high and is latched in an inverter circuit In 10 .
At time t3, the gate potential FPUN goes high, turning ON the transistor Trn 10 , but since the fuse E-Fuse is nonconducting, the potential at the node N 10 remains high. Accordingly, a transistor Trn 11 turns ON.
At time t4, the gate potential FPUN goes low, turning OFF the transistor Trn 10 , but since the potential at the node N 10 is still latched in the inverter circuit In 10 , the transistor Trn 11 remains ON.
From time t1 to t4, gate potentials FPUPd and FPUNd are both held low. Hence, transistors Trp 12 and Trn 12 are in the ON state and in the OFF state, respectively. Accordingly, the potential at a node N 11 is high at the beginning.
At time t5, the gate potential FPUPd goes high, turning OFF the transistor Trp 12 , but the potential at the node N 11 is still latched in an inverter circuit In 11 .
At time t6, the gate potential FPUNd goes low, turning ON the transistor Trn 12 . Since at this time the transistor Trn 11 is ON, the potential at the node N 11 goes low. As a result, a signal SELECT goes high.
At time t7, the gate potential FPUNd goes low, turning OFF the transistor Trn 12 , but since the potential at the node N 11 is latched as “low” in the inverter circuit In 11 , the signal SELECT remains high.
A description is given of the operation of the data decision circuit 40 a - 0 which is effected when the fuse E-Fuse is blown, that is when it is electrically treated and hence is conducting. In FIG. 3 , the operation is indicated by “E-Fuse Blow.” The operation from time t1 to t2 is the same as in the case where the fuse E-Fuse is nonconducting.
When the gate potential FPUN goes high at time t3, the transistor Trn 10 turns ON. Since the fuse E-fuse is conducting at this time, the potential at the node N 10 goes low, turning OFF the transistor Trn 11 .
At time t4, the gate potential FPUN goes low, turning OFF the transistor Trn 10 . At this time, the transistor Trp 10 is also OFF. Accordingly, the potential at the node N 10 is latched as being “low” in the inverter circuit In 10 . Hence, the transistor Trn 11 remains OFF.
At time t5, the gate potential FPUPd goes high, turning OFF the transistor Trp 12 , but the potential at the node N 11 is latched as being “high” in the inverter circuit In 11 .
At time t6 the gate potential FPUNd goes high, turning ON the transistor Trn 11 . Since the transistor Trn 11 is OFF at this time, the potential at the node N 11 remains high, making the signal SELECT low.
At time t7 the gate potential FPUNd goes low, turning OFF the transistor Trn 12 , but the potential at the node N 11 is still latched as being “high” in the inverter circuit In 11 . This causes the signal SELECT to remain low.
As described above, the data decision circuit 40 a - 0 outputs a high-level signal as the signal SELECT when the fuse E-Fuse is nonconducting, and outputs a low-level signal as the signal SELECT when the fuse E-Fuse is conducting. Accordingly, the data decision circuit 40 a - 0 changes the potential of the signal SELECT, depending on the fuse E-Fuse is conducting or nonconducting, and decides a bit value based on the potential of the signal SELECT. Incidentally, the electrical treatment of the fuse is also called trimming.
The data decision circuits 40 a - 0 to 40 a - 2 output 1-bit signals SELECTA 0 to SELECTA 2 , respectively, and the data decision circuits 40 b - 0 to 40 b - 2 also output 1-bit signals SELECTB 0 to SELECTB 2 , respectively.
The standard data decision circuit 60 outputs an inverted potential of the output potential shown in FIG. 2 . To perform this, the standard data decision circuit 60 has a configuration that includes an inverter additionally placed in the output unit shown in FIG. 2 or that excludes one of the existing inverters in the output unit shown in FIG. 2 . The standard data decision circuit 60 is identical in construction with that of FIG. 2 except the above.
In this embodiment, when the reference potential generator 100 outputs the standard potential as the reference potential VBGR, the signals PRETMBGR 0 to PRETMBGR 2 , which are sent to the decode circuit 20 , are set so that they all have the same bit values “111” (see FIG. 5 ). In this instance, the standard data decision circuit 60 sends signals SELDISABLEn of the same bit value to the data transfer circuits 30 - 0 to 30 - 2 . Accordingly, this embodiment requires only one standard data decision circuit 60 .
Referring back to FIG. 1 , the test signals TMFUSESEL 0 to TMFUSESEL 2 are input from outside in the test mode. Since the test signals TMFUSESEL 0 to TMFUSESEL 2 may be changed variously, digital data also may have various values. Based on such various pieces of digital data, any of the signals TMBGR 0 to TMBGR 4 can be selected.
In this embodiment, while not in the test mode, the test signals TMFUSESEL 0 to TMFUSESEL 2 are all in the low state “000”. AT this time, the data selection circuit 50 deselects the test signals TMFUSESEL 0 to TMFUSESEL 2 .
FIG. 4 is a circuit diagram showing the configuration of the data selection circuit 50 . The data selection circuit 50 is configured to select any one of the digital data output from the data decision circuits 40 a - 0 to 40 a - 2 , the digital data output from the data decision circuits 40 b - 0 to 40 b - 2 , and digital data composed of the test signals TMFUSESEL 0 to TMFUSESEL 2 .
For example, when the signals SELECTB 0 to SELECTB 2 are all high and the signals TMFUSESEL 0 to TMFUSESEL 2 are all low, the data selection circuit 50 makes both of signals DISABLEA and DISABLEB high. In this case, the data selection circuit 50 selects the digital data output from the data decision circuits 40 a - 0 to 40 a - 2 . Because any one of the signals SELECTB 0 to SELECTB 2 being low means that any one of the data decision circuits 40 b - 0 to 40 b - 2 is not trimmed (see FIG. 2 ), and the signals TMFUSESEL 0 to TMFUSESEL 2 being all low means that the current mode is not the test mode.
When any one of the signals SELECTB 0 to SELECTB 2 is low and the signals TMFUSESEL 0 to TMFUSESEL 2 are all low, the data selection circuit 50 makes the signal DISABLEA low, and the signal DISABLEB high. In this instance, the data selection circuit 50 selects the digital data output from the data decision circuits 40 b - 0 to 40 b - 2 . Because any one of the signals SELECTB 0 to SELECTB 2 being low means that any one of the data decision circuits 40 b - 0 to 40 b - 2 is trimmed, and the signals TMFUSESEL 0 to TMFUSESEL 2 being all low means that the current mode is not the test mode.
When any one of the signals TMFUSESEL 0 to TMFUSESEL 2 is high, the data selection circuit 50 makes both of the signals DISABLEA and DISABLEB low irrespective of the states of the signals SELECTB 0 to SELECTB 2 . In this instance, the data selection circuit 50 selects the digital data composed of the signals TMFUSESEL 0 to TMFUSESEL 2 . The reason for this is that any one of the signals TMFUSESEL 0 to TMFUSESEL 2 is high means the test mode.
As described above, the data selection circuit 50 is capable of selecting any one of the digital data output from the data decision circuits 40 a - 0 to 40 a - 2 , the digital data output from the data decision circuits 40 b - 0 to 40 b - 2 , and the digital data composed of the test signals TMFUSESEL 0 to TMFUSESEL 2 .
FIG. 5 is a table showing the relationships between the signals PRETMBGR 0 to PRETMBGR 2 and the signals TMBGR 0 to TMBGR 4 . This embodiment is set so that the signal TMBGR 2 generates the standard potential.
When the standard potential is used as the reference potential VBGR in the test mode, it is necessary to input, separately of the test signals TMFUSESEL 0 to TMFUSESEL 2 , a standard test signal TMFUSEIS that makes all of the signals PRETMBGR 0 to PRETMNBGR 2 high “111.” The reason for this is that in the case of making all of the signals PRETMBGR high by the test signals TMFUSESEL 0 to TMFUSESEL 2 , all the test signals need to be low “000,” which causes the data selection circuit 50 to deselect the test signals TMFUSESEL 0 to TMFUSESEL 2 . Accordingly, the test mode requires the standard test signal TMFUSEDIS that is used to output the standard potential.
As in the test mode, the data decision circuits 40 b - 0 to 40 b - 2 cannot be set to use the standard potential as the reference potential VBGR, either. The reason for this is that in the case of using the standard potential as the reference one VBGR, all of the signals SELECTB 0 to SELECTB 2 need to be high “111,” which causes the data selection circuit 50 to deselect the signals SELECTB 0 to SELECTB 2 . Accordingly, the standard data decision circuit 60 is required to set the standard potential as the reference potential VBGR.
FIG. 6 is a circuit diagram of the data transfer circuit 30 - 0 . The other data transfer circuits 30 - 1 to 30 - 2 are common in construction to the data transfer circuit 30 - 0 . It should be noted here that the data transfer circuits 30 - 0 to 30 - 2 each input thereto and output therefrom different data.
With reference to FIG. 6 , the configuration and the operation of the data transfer circuit 30 - 0 are described below. The broken-line box A indicates a configuration related to the data decision circuit 40 a - 0 , the broken-line box B indicates a configuration related to the data decision circuit 40 b - 0 , and the broken-line box C indicates a configuration related to the test mode.
In the broken-line box A, the data transfer circuit 30 - 0 receives the signal SELECTA 0 from the data decision circuit 40 a - 0 . The signal SELECTA 0 is sent via a transistor Trnp 15 to a node N 15 . The power supply voltage VDD is applied via a transistor Trp 15 to the node N 15 . Accordingly, the potential of a signal ASELECTA 0 at the node N 15 is either the potential of the signal SELECTA 0 or the potential of the power supply voltage VDD (always high).
The signal DISABLEA is the data output from the data selection circuit 50 (see FIG. 4 ). The signal TMFUSEDIS is used to output the standard potential as the reference potential VBGR in the test mode. The signal TMFUSEDIS is high only in the test mode, and is low in the other modes.
When the data selection circuit selects the data decision circuits 40 a - 0 to 40 a - 2 , the signal DISABLEA is high and the signal TMFUSEDIS is low. Accordingly, the transistor Trnp 15 turns ON and the transistor Trp 15 turns OFF. As a result, the signal SELECTA 0 is sent to the node N 15 , where it becomes the above-mentioned signal ASELECTA 0 .
When the data selection circuit 50 does not select the data decision circuits 40 a - 0 to 40 a - 2 , or in the test mode, the signal DISABLEA is low or the signal TMFUSEDIS is high. Accordingly, the transistor Trnp 15 turns OFF and the transistor Trp 15 turns ON. As a result, the power supply voltage VDD is applied to the node N 15 to generate the signal ASELECTA 0 . That is, in this case, the signal ASELECTA 0 is always high.
In the broken-line box B, the data transfer circuit 30 - 0 receives the signal SELECTB 0 from the data decision circuit 40 b - 0 . The signal SELECTB 0 is applied via a transistor Trnp 16 to a node N 16 . The power supply voltage VDD is applied via a transistor Trp 16 to the node N 16 . Accordingly, the potential of a signal ASELECTB 0 at the node N 16 is either the potential of the signal SELECTB 0 or the potential of the power supply voltage VDD.
When the data selection circuit 50 selects the data decision circuits 40 b - 0 to 40 b - 2 , the signal DISABLEB is high and the signal TMFUSEDIS is low. Accordingly, the transistor Trnp 16 turns ON and the transistor Trp 16 turns OFF. As a result, the signal SELECTB 0 is sent to the node N 16 , where it becomes the above-mentioned signal ASELECTB 0 .
On the contrary, when the data selection circuit 50 does not select the data decision circuits 40 b - 0 to 40 b - 2 , or in the test mode, the signal DISABLEB is low or the signal TMFUSEDIS is high. Accordingly, the transistor Trnp 16 turns OFF and the transistor Trp 16 turns ON. As a result, the power supply voltage VDD is applied to the node N 16 to generate the signal ASELECTB 0 . That is, in this case, the signal ASELECTB 0 is always high.
In the broken-line box C, the data transfer circuit 30 - 0 receives an external test signal TMFUSESEL 0 , which is always low except in the test mode and at the time of selecting the standard potential. A NAND gate G 1 is supplied with a signal bTMFUSESEL 0 that is an inverted version of the test signal TMFUSESEL 0 . That is, the signal bTMFUSESEL 0 is always high except in the test mode and at the time of selecting the standard potential.
As described above, signals from two deselected ones of the data decision circuits 40 a - 0 to 40 a - 2 (broken-line box A), the data decision circuit 40 b - 0 to 40 b - 2 (broken-line box B) and the test mode (broken-line box C) are always high. The NAND gate G 1 sends an inverted version of the signal from the selected box to a NAND gate G 2 . The NAND gate G 2 is supplied with the inverted signal and the signal SELDISABLE from the standard data decision circuit 60 . When the standard data decision circuit 60 is not selected, the signal SELDISABLE is always high. Accordingly, the signal from the selected one of the data decision circuit 40 a - 0 to 40 a - 2 (broken-line box A), the data decision circuits 40 b - 0 to 40 b - 2 (broken-line box B) and the test mode (broken-line box C) is output as the signal PRETMBGR 0 .
When the standard potential is selected, none of the data decision circuits 40 a - 0 to 40 a - 2 (broken-line box A), the data decision circuits 40 b - 0 to 40 b - 2 (broken-line box B) and the test mode (broken-line box) is selected, and the signal SEDISABLE from the standard data decision circuit 60 is output. At this time, the signals ASELECTA 0 and ASELECTB 0 are both high and the signal bTMFUSESEL 0 is low. As a result, the output from the NAND gate G 1 becomes always high, outputting the potential of the signal SEDISABLE as the signal PRETMBGR 0 .
As described above, the data transfer circuit 30 - 0 transfers any one of the signals SELECTA 0 , SELECTB 0 and bTMFUSESEL 0 or SELDISABLE as the signal PRETMBGR 0 .
FIG. 7 is a conceptual diagram of testing a semiconductor device equipped with the reference potential generator 100 . FIG. 8 is a flowchart of the procedure for testing the semiconductor device equipped with the reference potential generator 100 . In a front-end of the semiconductor manufacturing, semiconductor elements are formed on the semiconductor wafer.
The D/S step (S 10 ) begins with inputting the test signals TMFUSESEL 0 to TMFUSESEL 2 from outside (S 12 ). By changing or modifying the test signals TMFUSESEL 0 to TMFUSESEL 2 , it is possible to obtain pieces of digital data of various values. The next step is to measure reference potentials VBGR based on the pieces of digital data of various values (S 14 ). In the case of using the standard potential to conduct the test, the standard test signal TMFUSEDIS is input from outside.
The next step is to specify the digital data for generating the optimum reference potential VBGR closest to the design value (S 16 ). The data decision circuits 40 a - 0 to 40 a - 2 are trimmed to output the optimum digital data (S 18 ). The trimming can be achieved electrically without using a laser, and hence it can be done in the D/S step. Thereafter the semiconductor elements on the semiconductor wafer are tested for each die.
For example, when it is found that TMBGR 1 in FIG. 5 is the optimum, the data decision circuits 40 a - 0 to 40 a - 2 are so trimmed as to output “011.” When the optimum reference potential VBGR closest to the design value is the standard potential, the data decision circuits 40 a - 0 to 40 a - 2 are not trimmed. In this instance, the standard potential is output as the reference potential VBGR based on the digital data that the standard data decision circuit 60 outputs.
Redundancy (S 20 ) and a wafer final test (S 30 ) are carried out next. In this case, since the data decision circuits 40 a - 0 to 40 a - 2 are already trimmed, circuits (for example, memory circuit and so on) other than the reference potential generator 100 are trimmed in the redundancy step (S 20 ). In the wafer final test (S 30 ), the results of trimming in the redundancy step (S 20 ) are tested. Accordingly, the redundancy step (S 20 ) and the wafer final test step (S 30 ) are essentially unnecessary for the reference potential generator 100 .
Thereafter, in the assembling step, the semiconductor wafer is divided into individual semiconductor chips, which are each packaged (S 40 ). This is followed by a packaging test (S 50 ).
The reliability test (S 60 ) is then conducted. Semiconductor chips decided as defective in the reliability test includes those rejected by reason of variations of the reference potential VBGR. In this case, the external test signals TMFUSESEL 0 to TMFUSESEL 2 are input (S 62 ). By changing or modifying the test signals TMFUSESEL 0 to TMFUSESEL 2 , pieces of digital data of various values. The next step is to measure reference potentials VBGR based on the pieces of digital data of various values (S 64 ). In the case of using the standard potential to conduct the test, the standard test signal TMFUSEIS is input from outside.
The next step is to specify the digital data for generating the optimum reference potential VBGR closest to the design value (S 66 ). The data decision circuits 40 b - 0 to 40 b - 2 are trimmed to output the optimum digital data (S 68 ). The trimming can be achieved electrically without using a laser, and hence it can be done in the reliability test step.
For example, when it is found at the time of the reliability test that TMBGR 0 is optimum although TMBGR 1 was selected in the D/S step, the data decision circuits 40 b - 0 to 40 b - 2 are so trimmed as to output “101.” When the optimum reference potential VBGR closest to the design value is the standard potential, the data decision circuits 40 b - 0 to 40 b - 2 are not trimmed. In this instance, the standard potential is output as the reference potential VBGR based on the digital data that the standard data decision circuit 60 outputs.
Further, the semiconductor chips undergo a packaging final test (S 70 ). Thereafter the semiconductor chips are shipped as products. The semiconductor chips decided as non-defective in the reliability test of step S 60 undergo the packaging final test in step S 70 without going through steps S 62 to S 68 .
In this embodiment, the data selection circuit 50 is capable of selecting the test signals TMFUSESEL 0 to TMFUSESEL 2 . This allows the reference potential generator 100 to operate in the test mode in the D/S step (S 10 ) and to input various pieces of digital data from external. By this, it is possible to measure the actual reference potential VBGR corresponding to each piece of digital data. As a result, the data decision circuits 40 a - 0 to 40 a - 2 can be so trimmed as to output optimum digital data in the D/S step.
According to this embodiment, the data decision circuits 40 ab - 0 to 40 b - 2 are each equipped with the electrically treatable fuse E-Fuse. Accordingly, the data decision circuits 40 b - 0 to 40 b - 2 can be trimmed in the reliability test (S 60 ). This trimming permits correction of a shift or deviation of the reference voltage VBGR due to stresses applied to the semiconductor chip in the assembling step (S 40 ) or in the packaging test (S 50 ). As a result, it is to recover the semiconductor chips rejected as defective in the reliability test (S 60 ).
In the reliability test (S 60 ), too, the data selection circuit 50 is capable of selecting the test signals TMFUSESEL 0 to TMFUSESEL 2 . This allows the reference potential generator 100 to operate in the test mode in the D/S step (S 10 ) to input various pieces of digital data from external. By this, it is possible to measure the actual reference potential VBGR corresponding to each piece of digital data. As a result, the data decision circuits 40 b - 0 to 40 b - 2 can be so trimmed as to output optimum digital data in the reliability test.
The data decision circuits 40 a - 0 to 40 a - 2 are each provided with the electrically treatable fuse E-Fuse. Accordingly, in the D/S step (S 10 ) it is possible to perform trimming of the data decision circuits 40 a - 0 to 40 a - 2 as well as the electrical test including the measurement of the reference potential VBGR.
The data decision circuits 40 a - 0 to 40 a - 2 may be of such a configuration as shown in FIG. 16 . In such an instance, a laser trimming step is needed separately of the D/S step. On the other hand, the data decision circuits 40 b - 0 to 40 b - 2 each have the configuration shown in FIG. 2 , and hence they can be re-trimmed in the reliability test (S 60 ) to output optimum digital data.
While in this embodiment, the digital data has been described as being 3-bit data, it may also be of 2 or 1 bit, or 4 or more bits. In this case, the data decision circuits 40 a , 40 b and the data transfer circuits 30 are respectively provided by a number equal to that of bits of the digital data used. The number of the test signals TMFUSESEL to be input from outside is also equal to the number of bits.
For example, when the digital data is 8-bit, the reference potential generator 100 needs only to be provided with data decision circuits 40 a - 0 to 40 a - 7 , data decision circuits 40 b - 0 to 40 b - 7 and data transfer circuits 30 - 0 to 30 - 7 . In the test mode test signals TMFUSESEL 0 to TMFUSESEL 7 are input from outside.
In the above the signals PRETMBGR 0 to PRETMBGR 2 are set at “111,” but this value can properly be changed. This can be done by changing the settings of the signals TMFUSESEDIS and the standard data decision circuit 60 to conform with the signals PRETMBGR 0 to PRETMBGR 2 which generate the standard potential.
(Second Embodiment)
FIG. 9 is a block diagram of a reference potential generator 200 according to a second embodiment of the present invention. The reference potential generator 200 does not have the decode circuit 20 , and the signals TMBGR 0 to TMBGR 4 are transferred directly to the reference potential selection circuit 10 from a data transfer circuits 32 - 0 to 32 - 3 and a standard data transfer circuit 34 . Like parts corresponding to those in the first embodiment are designated by like reference numerals. In this embodiment, the signals TMBGR 0 to TMBGR 4 are used as digital data. When the signal TMBGR 2 is high, the standard potential is output as the reference potential VBGR.
The data decision circuits 40 a , the data decision circuits 40 b and the data transfer circuits 32 are respectively provided by a number equal to that having subtracted the reference potential from the number of signals TMBGR, that is, equal to a number having subtracted by one from the number of bits forming the digital data. In this embodiment, the reference potential generator 200 includes: data decision circuits 40 a - 0 , 40 a - 1 , 40 a - 3 and 40 a - 4 (hereinafter referred to also as data decision circuits 40 a - 0 to 40 a - 4 ); data decision circuits 40 b - 0 , 40 b - 1 , 40 b - 3 and 40 b - 4 (hereinafter referred to also as data decision circuits 40 b - 0 to 40 b - 4 ); and data transfer circuits 32 - 0 , 32 - 1 , 32 - 3 and 32 - 4 (hereinafter referred to also as data transfer circuits 32 - 0 to 32 - 4 ).
A data selection circuit 52 and the standard data transfer circuit 34 are used to select the standard potential as the reference potential VBGR.
FIG. 10 is a circuit diagram of the standard data selection circuit 52 . The standard data selection circuit 52 outputs a high-level signal when any one of signals TMBGR 0 , TMBGR 1 , TMBGR 3 and TMBGR 4 (hereinafter referred to also as signals TMBGR 0 to 4) is high. When the signals TMBGR 0 to 4 are all low, the standard data selection circuit 52 outputs a low-level signal. That is, the standard data selection circuit 52 outputs the high-level signal as the signal DISABLE in the case of deselecting the signal TMBGR 2 , and outputs the low-level signal as the signal DISABLE in the case of selecting the signal TMBGR 2 .
FIG. 11 is a circuit diagram of the standard data transfer circuit 34 . The standard data transfer circuit 34 responds to the signal DISABLE from the standard data selection circuit 52 to select (high) or deselect (low) the signal TMBGR 2 . A signal SELECT 2 is high. Accordingly, the standard data transfer circuit 34 deselects (low) the signal TMBGR 2 when the signal DISABLE is high, and selects (high) the signal TMBGR 2 when the signal DISABLE is low. In this way, the standard data selection circuit 52 and the standard data transfer circuit 34 select the signal TMBGR 2 . As a result, the standard potential is output as the reference potential VBGR.
FIG. 12 is a circuit diagram of a data selection circuit 54 . The data selection circuit 54 outputs the signal DISABLEA for deselecting the data decision circuits 40 a - 0 to 40 a - 4 when the data decision circuits 40 b - 0 to 40 b - 4 are selected.
The data selection circuit 54 outputs a high-level signal when the data decision circuits 40 a - 0 to 40 a - 4 are selected in the D/S step. Thereafter, when the data decision circuits 40 b - 0 to 40 b - 4 are selected in the reliability test, any one of signals SELECTB 0 , 1 , 3 and 4 becomes low. As a result, the data selection circuit 54 outputs a low-level signal as the signal DISABLEA.
FIG. 13 is a circuit diagram of the data transfer circuit 32 - 0 . Since the data transfer circuits 32 - 1 , 32 - 2 and 32 - 3 have the same configuration as that of the data transfer circuit 32 - 0 , no description is repeated in connection with them. The broken-line box A 2 indicates a configuration related to the data decision circuit 40 a - 0 , the broken-line box B 2 indicates a configuration related to the data decision circuit 40 b - 0 , and the broken-line box C indicates a configuration related to the test mode.
In the broken-line box A 2 , the data transfer circuit 32 - 0 inputs the signal SELECTA 0 from the data decision circuit 40 a - 0 . The signal SELECTA 0 is applied via a transistor Trnp 17 to a node N 17 . The power supply voltage VDD is applied via a transistor Trp 17 to the node N 17 . Accordingly, the potential of the signal ASELECTA 0 at the node N 17 is either the potential of the signal SELECTA 0 or the potential (high) of the power supply voltage VDD.
A signal SELDISABLE 0 is data output from a standard data decision circuit 60 (see FIG. 9 ). When the standard data decision circuit 60 is not used, signals SELDISABLE 0 to SELDISABLE 4 are all high, whereas when the standard data decision circuit 60 is used, the signals SELDISABLE 0 to SELDISABLE 4 are all low. The signal TMFUSEDIS is used to output the standard potential as the reference potential VBGR in the test mode. The signal TMFUSEDIS is high only in the test mode and low in the other modes. The signal DISABLEA is fed from the data selection circuit 54 , and it is high when the data decision circuits 40 a - 0 to 40 a - 4 are selected, and low when the data decision circuits 40 a - 0 to 40 b - 4 are selected.
When the data decision circuits 40 a - 0 , 40 a - 1 and 40 a - 3 are selected, the signals SELDISABLE 0 and DISABLEA are high, but the signal TMFUSEDIS is low. Accordingly the transistor Trnp 17 turns ON, whereas the transistor Trp 17 turns OFF. As a result, the signal SELECTA 0 is sent to the node N 17 to form the signal ASELECTA 0 .
When the standard data decision circuit 60 is selected, or the data decision circuits 40 b - 0 to 40 b - 4 are selected, or in the test mode, the signal SELDISALE 0 is low, the signal DISABLEA is low, or the signal TMFUSEDIS is high. Accordingly, the transistor Trnp 17 turns OFF and the transistor Trp 17 urns ON. As a result, the potential of the power supply voltage VDD is sent to the node N 17 to form the signal ASELECTA 0 . AT this time, the signal ASELECTA 0 becomes high.
In the broken-line box B 2 , the data transfer circuit 32 - 0 inputs the signal SELECTB 0 from the data decision circuit 40 b - 0 . The signal SELECTB 0 is applied via a transistor Trnp 18 to a node N 18 . The power supply voltage VDD is applied via a transistor Trp 18 to the node N 18 . Hence, the potential of the signal ASELECTB 0 at the node N 18 is either the potential of the signal SELECTB 0 or the potential (high) of the power supply voltage VDD.
When the data decision circuits 40 b - 0 to 40 b - 3 are selected, the signal SELDISABLE 0 is high and the signal TMFUSEDIS is low. Accordingly, the transistor Trnp 18 turns ON and the transistor Trp 18 turns OFF. As a result, the signal SELECTB 0 is sent to the node N 18 to form the signal ASELECTB 0 . Since in this case the signal DISABLEA is low, the data decision circuits 40 a - 0 to 40 a - 4 are deselected.
On the contrary, when the standard data decision circuit 60 is selected, or in the test mode, the signal SELDISABLE 0 is low, or the signal TMFUSEDIS is high. Accordingly, the transistor Trnp 18 turns OFF and the transistor Trp 18 turns ON, through which the potential of the power supply voltage VDD is sent to the node N 18 to form the signal ASELECTB 0 . In this case, the signal ASELECTB 0 is always high.
In the broken-line box C, the data transfer circuit 32 - 0 inputs the external test signal TMFUSESEL 0 , which is always low except in the test mode.
In the test mode, high-level signals are always applied to two inputs of a NAND gate G 10 irrespective of the state of the data decision circuits 40 a - 0 and 40 b - 0 . Accordingly, a NAND gate G 11 is supplied with a high-level signal from the NAND gate G 10 , and outputs the signal TMFUSESL 0 as the signal TMBGR 0 .
In the case of outputting the standard potential as the reference potential VBGR, the potential (high) of the power supply voltage VDD is sent to both inputs of the NAND gate G 1 . The signal TMFUSESEL 0 is low. Hence, the signal TMBGR 0 is output as a low-level signal from the NAND gate G 11 .
“The signal TMBGR 0 is low” means the signal TMBGR 0 is not selected. Accordingly, by making all of the signals TMBGR 0 to TMBGR 4 , except TMBGR 2 , low by the data transfer circuits 32 - 0 to 32 - 4 , the standard potential can be selected as the reference potential VBGR. In this instance, the data selection circuit 53 and the standard data transfer circuit 34 select the signal TMBGR 2 as described above. As a result, the reference potential VBGR becomes the standard potential.
When the standard data decision circuit 60 is not selected, or not in the test mode, the signal TMFUSESEL 0 is low. Accordingly, data from any one of the data decision circuit 40 a - 0 to 40 a - 3 or 40 b - 0 to 40 b - 3 is output as the signal TMBGR 0 from the NAND gate G 11 .
Since the test procedure of the reference potential generator 200 is the same as that in the first embodiment described previously with reference to FIGS. 7 and 8 , no description is repeated.
While in the second embodiment the digital data is 5-bit data, it is not limited specifically thereto but the number of bits may be of 4 or smaller or more than 6. In this case, the data decision circuits 40 a , the data decision circuits 40 b and the data transfer circuits 30 are respectively provided by the number smaller by one than the number of bits used. Similarly, the number of external test signal TMFUSESEL is also set as above.
This embodiment produces the same effects as obtainable with the first embodiment. This embodiment requires no decode circuit.
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A semiconductor device that generates a desired internal power supply by using, as a reference potential, a potential obtained by adjusting a preset standard potential, the semiconductor device comprises; a reference potential selection circuit selecting the reference potential on the basis of digital data from among a plurality of potentials of different levels which are obtained by dividing a power supply voltage, and outputting the reference potential instead of the standard potential; a first decision circuit deciding bits of the digital data; a second decision circuit deciding the bits of the digital data, separately from the first decision circuit; and a data transfer circuit transferring to the reference potential selection circuit the digital data which is decided by either one of the first and second decision circuits.
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FIELD OF THE INVENTION
Oral malodor and periodontitis are common problems affecting a large percentage of the human population. The present invention provides oral diagnostic tests to determine a person's oral malodor capacity and potential to develop periodontitis. In particular, the present invention provides an oral diagnostic test which measures the oral putrefaction potential of a patient following a cysteine or cystine challenge. A method of assessing the effectiveness of a dental therapeutic agent or device to reduce oral malodor and periodontitis is also provided by the present invention.
BACKGROUND OF THE INVENTION
Halitosis is the general term used to describe unpleasant breath emitted from a person's mouth regardless of whether the odorous substances in the breath originate from oral or non-oral sources. Oral malodor refers to the contribution of malodorous substances arising from oral sources. Oral malodor is primarily produced during oral bacterial putrefaction, a process whereby peptides and proteins are hydrolyzed by oral bacteria and the resulting amino acids are further catabolized. Oral bacterial putrefaction is the collection of biochemical processes that involves the degradation of peptides and proteins by the oral microbes into amino acids which are then further degraded into end-products that include some that are odorous and others that are harmful to the oral soft tissues.
It is generally recognized in the dental literature that the volatile sulfur compounds, hydrogen sulfide (H 2 S), methylmercaptan (CH 3 S 5 H) and dimethylmercaptan ((CH 3 ) 2 S) are major contributors of oral malodor. Persson et al. (1990) "The Formation of Hydrogen Sulfide and Methyl Mercaptan by Oral Bacteria", Oral Microbiol. Immunol., 5:195-201. These malodorous volatile sulfur compounds (VSC) are generated during oral putrefaction of sulfur containing amino acids, either free or originating from peptides or proteins. Sulfur containing amino acids are readily available in saliva, dental plaque, gingival crevices, periodontal pockets, and desquamating mucosal epithelial cells. They may also be derived from proteinaceous food particles trapped between the teeth, lodged in the gingival crevices or found on the mucous membranes of the oral cavity, especially the tongue.
In addition to the volatile sulfur compounds, other odorigenic substances may be produced by the plaque bacteria. Indole and skatole are produced during the catabolism of tryptophan. Putrescine and cadaverine are produced during the catabolism of arginine and ornithine respectively, and odorous fatty acids such as butyric and valeric may be produced from several other amino acids. Researchers have found that the volatile sulfur compounds are often present in the head space and vapor of putrefied saliva and in individual samples of mouth air. Tonzetich J. (1977) "Production and Origin of Oral Malodor: Review of Mechanisms and Methods of Analysis." J. Periodontology, 48: 13.
Previous studies have suggested detecting halitosis by measuring the concentration of hydrogen sulfide and methyl mercaptan in a person's breath. For example, U.S. Pat. No. 3,507,269, describes a clinical device for diagnosing the various causative factors of halitosis, including measuring hydrogen sulfide and methyl mercaptan. These compounds were measured by inserting a device having an absorbent material containing a 2% solution of lead acetate. The concentration of hydrogen sulfide and methyl mercaptan were determined colorimetrically. These studies have not suggested, however, a way to measure an individual's capacity to produce oral malodor or potential to develop periodontitis. Moreover, previous studies have not described quantitative methods of measuring oral malodor and periodontitis potentials.
Oral malodor has been found to be involved in or associated with the pathogenesis of periodontal disease. Microbiological studies have demonstrated that periodontal pathogenic microorganisms readily degrade sulfur containing compounds. In particular, Gram-negative bacteria such as Fusobacterium nucleatum and Porphyromonus gingivalis were found to readily degrade sulfur containing amino acids and proteins to produce volatile sulfur containing compounds. These volatile sulfur compounds were found to increase the permeability of the oral mucosa and collagen solubility, and to decrease protein or collagen synthesis. Tonzetich J. (1984) "Effect of Hydrogen Sulfide and Methyl Mercaptan on the Permeability of Oral Mucosa", J. Dent. Res. 63:994. Additionally, patients with periodontal disease were shown to have an eight times greater concentration of volatile sulfur compounds compared to patients without periodontal disease. Yaegaki et al. (1992) "Bioclinical and Clinical Factors Influencing Oral Malodor in Periodontal Patients", J. Periodontal., 63:783-787.
After an extensive survey of the amino acids and various peptides, it has been discovered in the present invention that cysteine and cystine are the major causative agents responsible for lowering the oxidation-reduction potential (E h ) of the oral cavity. An oral cavity with a low E h favors an ecological environment that enables Gram-negative bacteria in the mouth to grow, engage in oral putrefaction, and produce the undesirable conditions of oral malodor and periodontitis. It has been surprisingly discovered in accordance with the present invention that both the oral malodor producing capacity and the potential for developing periodontitis can be determined following an oral challenge with a mouth rinse containing cysteine or cystine.
Identifying the susceptibility of a person to a particular disease or physiologic condition has become an increasingly effective approach to combat various diseases in recent years. One of the earliest diagnostic tests of this type is the glucose challenge used to determine the ability of a person to utilize glucose and in turn, the potential of a person to develop diabetes. The present invention describes novel oral diagnostic tests for quantitatively measuring an individual's oral malodor producing capacity and potential for developing periodontitis. Until the advent of this invention, providing a patient with a quantitative analysis of their potential of developing oral malodor or periodontitis has not been readily available.
SUMMARY OF THE INVENTION
The present invention relates to an oral diagnostic test for determining the oral malodor producing capacity of a person by administering a mouth rinse containing cysteine or cystine and quantitatively measuring in vivo or in vitro the VSC produced in the oral cavity.
The present invention further relates to an oral diagnostic test for determining a person's potential to develop periodontitis by administering a mouth rinse containing cysteine or cystine and quantitatively measuring in vivo or in vitro the oxidation-reduction potential (E h ) of the oral cavity.
Another aspect of this invention is directed to a method of monitoring the effectiveness of a dental therapeutic or device to treat oral malodor or periodontitis comprising measuring in vivo the VSC or the E h , respectively, of the oral cavity before and after the dental therapeutic administered or the dental device is employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the E h , and VSC responses in vivo following a challenge with a 6 mM cysteine solution.
FIG. 2 shows the simultaneous E h and VSC responses in vitro following a challenge with a 6 mM cysteine solution;
FIG. 3 shows the VSC produced in vivo of mouth air following repetitive challenges with a 6 mM cysteine solution.
FIG. 4 shows the effect of a commercial mouthwash (Scope) on the oral malodor following a cysteine challenge in vivo.
FIG. 5 shows the effect of a commercial mouthwash (Scope) plus zinc chloride on oral malodor following cysteine challenge in vivo.
DETAILED DESCRIPTION OF THE INVENTION
The essential components of the invention and relevant proportions of components are set forth below. All patents, publications and test methods mentioned herein are incorporated by reference.
The present invention is directed to methods of determining the oral malodor producing capacity of a person and his or her potential for developing periodontitis using various oral diagnostic tests. As defined by the present invention, the oral malodor producing capability is the ability of a person's oral flora to produce offensive oral malodor. Unlike previous oral malodor tests which qualitatively measure an individual's bad breath, the present invention provides a quantitative assay for measuring the potential of a person's oral flora to produce oral malodor. The potential for developing periodontitis may also be determined in accordance with the invention, by measuring the decrease in the E h following a mouthrinse containing cysteine or cystine.
The mouth rinses used in the oral diagnostic tests of this invention contain cysteine or cystine in a concentration generally ranging from approximately 3 mM to approximately 10 mM. In a preferred embodiment, the cysteine or cystine concentration in the rinse ranges from 5 mM to 6 mM. In addition to cysteine or cystine, the mouth rinse used in the methods of the present invention may also contain any conventional mouth rinse ingredient. (See U.S. Pat. Nos. 4,226,851; 4,209,754; 4,289,755; and 5,104,644). For example, the mouth rinse may contain a solvent such as distilled or deionized water, ethanol and the like; a sweetening agent such as saccharine, aspartame and the like; and a flavoring agent such as peppermint oil, spearmint oil and the like.
The pH of the mouth rinse generally ranges from about 6.0 to about 8.0. In a preferred embodiment, the pH ranges from about 6.5 to about 7.5. The pH of the mouth rinse described herein can be controlled with acid such as hydrochloric and with base such as sodium hydroxide or buffered with buffering agents such as sodium phosphate.
In the in vivo method of assessing a person's oral malodor capacity and potential for developing periodontitis, the E h and VSC of the oral cavity are initially determined. It is preferred that these measurements are done before the patient consumes any food or beverages or before oral hygiene, such as early in the morning.
The VSC of the oral cavity may be determined using a VSC indicator means, which is defined as any conventional technique capable of quantitatively measuring the VSC produced in the oral cavity. For example, the VSC may be quantitatively measured using a sulfide detector instrument such as a Halimeter Model RH-17A, Interscan Portable Analyzer). The Halimeter has a mouth piece attached to one end which pumps a person's breath into the instrument. A sulfur detector measures the VSC in the breath sample. In another embodiment, a small tube may be placed on the Halimeter to measure the VSC at specific sites in the oral cavity. The VSC of the oral cavity may be determined by calculating the average VSC level for the various sites analyzed.
The oxidation-reduction potential (E h ) of the oral cavity may be quantitatively measured using a platinum or gold electrode with a silver/silver chloride reference electrode connected to a pH meter wherein the pH meter is used as a millivoltimeter. The E h of various sites in the oral cavity such as periodontal pockets, the tongue and between the teeth, may be measured using an electrode connected to a millivoltimeter. The electrode is placed in these various sites and the E h is measured. The over-all E h of the oral cavity may be calculated by averaging the measurements of the various sites measured.
The mouth rinse may be administered for example, by having the patient rinse his/her mouth with approximately 5 to 10 ml of the cysteine or cystine mouthrinse for approximately 30 to 60 seconds and expectorate. The rinse may also be administered by straying the mouthrinse in the patient's mouth. Following the administration of the mouthrinse, there is generally a resting period of approximately two to five minutes before the VSC and/or E h are measured.
It has been discovered in accordance with this invention that a VSC level ranging from 0 to about 100 ppb is indicative of an oral flora with a normal oral malodor producing capability. A VSC level greater than 100 ppb has been found to be indicative of an oral flora with an oral malodor producing capability above normal. The greater the VSC level following the mouth rinse of this invention, the greater the capacity an individual has for producing oral malodor. With respect to periodontitis, an E h , below approximately 40 to 50 MV has been found to be indicative of an oral flora capable of producing periodontitis. The lower the E h following the mouthrinse of this invention, the greater potential an individual has for developing periodontitis.
The present invention further provides an in vitro oral diagnostic test for quantitatively measuring a person's oral malodor producing capacity and potential for developing periodontitis. In one embodiment, a sample of whole saliva is collected from an individual using conventional techniques (e.g. chewing paraffin wax) and incubated at 37° C. with a cysteine or cystine solution for a time ranging from approximately 30 minutes to 8 hours. The incubation may be maintained at 37° C. using, for example, a water bath. The concentration of cysteine or cystine in the solution may range from approximately 3 mM to 10 mM and preferably between approximately 5 mM to 6 mM.
During the incubation, the VSC produced in the incubation mixture may be quantitatively measured using a VSC indicator means, such as a Halimeter. For example, samples of the air space in the incubation tubes may be collected using a small tube connected to the Halimeter and analyzed for VSC.
The E h of the incubation mixture may be quantitatively measured, for example, using a platinum or gold electrode with a silver/silver chloride or mercury/mercury chloride (calomel) reference electrode connected to a pH meter with or without a salt bridge wherein the pH meter is used as a millivoltimeter. The measuring end of the platinum or gold reference electrode system is placed in the incubation mixture. The Eh is quantitatively measured by comparing the E h of an incubation sample with and without a cysteine or cystine solution.
In another embodiment of the in vitro method, the saliva sample may be fractionated into salivary sediment and salivary supernatant prior to the incubation using conventional techniques such as centrifuging the saliva sample and decanting the salivary supernatant. (See, Ryan and Kleinberg (1995) Arch. Oral Biol., 40, 743-752). Once the salivary sediment is separated from the supernatant, the sediment may be washed with distilled water before resuspending it at any desired concentration with the previously decanted or other salivary supernatant.
In a further embodiment of this invention, the oral malodor producing capacity may be measured in vitro by preparing an incubation mixture containing salivary sediment, salivary supernatant, phosphate buffer and cysteine or cystine. In one embodiment, the incubation mixture contains, for example, 16.7% (v/v) salivary sediment, 33.3% (v/v) salivary supernatant, 60 mM phosphate buffer and cysteine or cystine ranging from approximately 3 mM to approximately 10 mM. The incubation may be run for a time ranging from approximately 30 minutes to 8 hours. During the incubation, the VSC and the E h may be measured as described herein. Specifically, the VSC can be measured with a sulfide detector instrument such as an Halimeter and the E h may be measured using a platinum or gold E h electrode in conjunction with a silver/silver chloride calomel reference electrode connected to a pH meter used as a millivoltimeter.
A VSC level ranging from 0 to about 100 ppb has been found to be indicative of an oral flora with a normal oral malodor producing capability. In contrast, a VSC level greater than 100 ppb is indicative of an oral flora with an oral malodor producing capability above normal. The greater the VSC level, the greater the capacity an individual has for producing oral malodor. An E h below approximately 40 to 50 MV is indicative of an oral flora capable of producing periodontitis. The lower the E h , the greater the potential an individual has for developing periodontitis.
The present invention has further identified a method of monitoring the effectiveness of a dental therapeutic or dental device to treat oral malodor and periodontitis by comparing the VSC and E h of the oral cavity following a mouth rinse containing cysteine or cystine prior to and subsequent to the administration of the dental therapeutic. In accordance with the method described herein, the VSC concentration of the oral cavity is initially measured to establish a baseline. The dental therapeutic is subsequently administered to the patient as directed to reduce or prevent oral malodor. To test the effectiveness of a dental device such as a toothbrush, dental floss, or a tongue scraper, to reduce the bacterial load and thereby reducing oral malodor the dental device is used as directed. The VSC concentration of the oral cavity is subsequently determined following the administration of the dental therapeutic or device. The measurement obtained is compared to the baseline measurement to calculate the VSC concentration. A decrease in the VSC concentration is indicative that the therapeutic or device is capable of reducing oral malodor. The greater the decrease in the VSC concentration, the more effective the therapeutic.
To determine the effectiveness of a dental therapeutic or device to treat periodontitis, a baseline E h is established by taking measurements throughout the oral cavity as previously described and averaging the measurements. A dental therapeutic is subsequently administered or the dental device is used as instructed. The E h of the oral cavity is measured and compared to the baseline measurement. An increase in the E h is indicative that the therapeutic or device is effective in reducing or preventing periodontitis.
In order to further illustrate the present invention, the experiments described in the following examples were carried out. It should be understood that the invention is not limited to the specific examples or the details described therein. The results obtained from the experiments described in the examples are shown in the accompanying figures and tables.
EXAMPLE I
This example describes an in vivo method of determining simultaneously the oral malodor producing capacity of a person and his/her potential to develop periodontitis. The patient examined in this study periodically suffered from oral malodor but did not have any clinical signs of periodontitis.
The VSC in the oral cavity, which arises mostly from the dorsal surface of the tongue, was measured using an Halimeter (Model RH-17A, Interscan Portable Analyzer) to determine the oral malodor producing capacity of a person. The potential of a person to develop periodontitis was determined by measuring the E h of the oral cavity. The E h of the dorsal surface of the tongue was measured using a platinum electrode with a silver/silver chloride reference electrode connected to the left forearm and both in turn were connected to a pH meter used as a millivoltimeter (Radiometer).
The VSC and E h of the oral cavity were initially measured to establish a baseline measurement. Following these measurements, a person was instructed to rinse with 5 ml of a 6 mM cysteine solution for approximately 30 to 60 seconds and expectorate. Approximately two to five minutes following the rinse, the VSC and the E h of the oral cavity were measured (FIG. 1).
The oral malodor producing capacity of a person was quantitatively determined by examining the amount of VSC produced following the rinse. The amount of VSC produced for a person with a normal oral malodor producing capacity is generally below about 100 to 200 ppb. An individual with an abnormal oral malodor producing capacity will readily degrade odorigenic substances to produce VSC at levels from approximately 100 to 200 ppb to as high as or higher than 1500 ppb. As shown in FIG. 1, the patient examined in this study has an high potential of producing oral malodor. The VSC levels were over 1500 ppb following a cysteine challenge rinse.
The potential for the patient studied in this example to develop periodontitis was determined by measuring the E h within the oral cavity following a cysteine challenge. The E h for a person without periodontitis or a potential developing periodontitis is generally above about 40 to 50 MV. A person with a potential for developing periodontitis generally has an E h below about 40 to 50 MV and as low as -200 MV. As shown in the data of FIG. 1, the patient studied did not have a great potential for developing periodontitis.
This study demonstrates that the potential of a person to produce oral malodor and develop periodontitis can be quantitatively measured. Moreover, shifts in oral flora affecting these parameters can be monitored over time to assess changes in a person's oral malodor producing capacity and potential for developing periodontitis.
EXAMPLE II
This example describes an in vitro method of determining simultaneously the oral malodor producing capacity and potential for a person to develop periodontitis. The patient examined in this study did not have any symptoms of oral malodor or periodontitis.
Whole saliva from a patient was collected, washed and separated as previously described by Kleinberg et al. (1973) Archs. oral Biol. 18, 787-798. An incubation mixture was prepared containing: 16.7% (V/V) salivary sediment, 33.3% (V/V) salivary supernatant, 60 mM phosphate buffer and 6 mM cysteine or cystine. The incubation was run for four hours in a water bath at 37° C. Following the incubation, the VSC of the incubation mixture was quantitatively measured using a Halimeter (Model RH-17A Interscan Portable Analyzer). The E h of the incubation was measured using a platinum electrode and a saturated potassium chloride salt bridge leading from a calomel reference electrode with both electrodes connected to a pH meter used as a millivoltimeter (Radiometer).
The oral malodor producing capacity of the patient was determined by examining the amount of VSC produced before and after degradation by the bacteria in the incubation of added cysteine. The amount of VSC produced for a normal person with low oral malodor producing potential is generally below about 100 to 200 ppb. An individual with an abnormal oral malodor producing potential will readily degrade odorigenic substances to produce volatile sulfur containing compounds at levels above approximately 100 to 200 ppb to as high as 1500 ppb.
The overall VSC produced during the incubation was calculated by subtracting the baseline VSC from the VSC produced following cysteine degradation. The results in FIG. 2 show a patient with a low oral malodor producing capacity.
A patients potential for producing periodontitis was determined by measuring the E h of the incubation mixture before and after a cysteine challenge to the incubation mixture. The E h for a person without periodontitis or a potential for developing periodontitis is generally above about 40 to 50 MV, while a person with a greater potential for having periodontitis generally has an E h below about 40 to 50 MV. The lower the E h , the greater the potential for developing periodontitis.
The overall E h produced during the incubation is calculated by subtracting the baseline E h from the E h produced following the cysteine challenge. The potential for a person to develop periodontitis is determined by measuring the E h change during the incubation. As shown in FIG. 2, the patient examined did not show a significant potential of producing periodontitis.
EXAMPLE III
This example describes an in vivo method to determine the effectiveness of an oral therapeutic to treat oral malodor and to determine the effectiveness of improving its oral malodor reducing capability.
According to this method, the baseline VSC level was measured as described in Example I and the person was instructed to rinse for 30 seconds with 5 ml of a 6 mM cysteine solution. The VSC was immediately measured after the rinse and subsequently at 2 minute intervals thereafter for 20 minutes. Following this cysteine challenge episode, the patient was instructed to rinse with water and VSC was measured again at 2 minute intervals for 20 minutes. Following the water rinse, the patient rinsed successively five times with 5 mM of the 6 mM cysteine solution and the VSC was measured as before. The water rinse served in this sample as a control. The successive cysteine rinses enable measurement of the oral malodor producing capacity of the oral bacteria and the duration of effectiveness of an oral therapeutic under test. The results for the water control which had no effect are shown in FIG. 3. As shown in FIG. 3, after each cysteine challenge, significant amounts of VSC were produced, indicating the patient is prone to oral malodor production.
Following the baseline measurements, a similar second series of rinses was run to test the effectiveness of the commercial mouth rinse SCOPE (FIG. 4). To test the effectiveness of zinc chloride to inhibit oral malodor production, it was added to the mouth rinse SCOPE at a concentration of 12 mM and tested. The results are shown in FIG. 5.
Water had no oral malodor reducing capability. The commercial mouthwash SCOPE also had little to no oral malodor reducing capability. Addition of zinc chloride dramatically reduced the malodor producing capability of cysteine. The reduction could be quantitatively measured over time. The duration of the reduction in VSC, as indicated by the delay in return to the baseline cysteine response, indicates that this rinse was effective in reducing VSC production over an extended period of time.
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Oral malodor and periodontitis are common problems affecting a large percentage of the population. The present invention provides a method of assessing an individual's oral malodor producing capacity and potential for developing periodontitis. In particular, the present invention is directed to identifying those individuals prone to oral malodor and periodontitis by measuring the formation of volatile sulfur compounds (VSC) and reduction in E h following a challenge with cysteine or cystine. A method of assessing the effectiveness of a dental therapeutic or device to treat oral malodor and/or periodontitis is also provided by this invention.
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This application is a continuation of application Ser. No. 09/512,388, filed on Feb. 25, 2000 and now abandoned, which is a continuation of 09/050,744 filed Mar. 30, 1998 now issued U.S. Pat. No. 6,066,765 which was a divisional of 08/812,138 filed Mar. 6, 1997 now issued U.S. Pat. No. 5,756,548 which was a continuation of Ser. No. 08/415,677 filed on Apr. 3, 1995 and now abandoned.
FIELD OF THE INVENTION
This invention concerns benzamide compounds, pharmaceutical compositions containing these compounds, and their use to treat or protect against neurodegenerative conditions.
BACKGROUND INFORMATION
Neurodegenerative disease encompasses a range of seriously debilitating conditions including Parkinson's disease, amyotrophic lateral sclerosis (ALS, “Lou Gehrig's disease”), multiple sclerosis, Huntington's disease, Alzheimer's disease, diabetic retinopathy, multi-infarct dementia, macular degeneration and the like. These conditions are characterized by a gradual but relentless worsening of the patient's condition over time. The mechanisms and causes of these diseases are becoming better understood and a variety of treatments have been suggested. One of these neurodegenerative conditions, Parkinson's disease, is associated with abnormal dopamine depletion in selected regions of the brain.
Recent summaries of the state of understanding of Parkinson's disease are provided by Marsden, C. D., in “Review Article—Parkinson's Disease” Lancet (Apr. 21, 1990) 948-952 and Calne, D. B., in “Treatment of Parkinson's Disease” NEJM (Sep. 30, 1993) 329:1021-1027. As these reviews point out, dopamine deficiency was identified as a key characteristic of Parkinson's disease, and the destruction of the dopaminergic nigrostriatal pathway paralleled dopamine depletion in Parkinson's patients.
Rapid development of Parkinson's-like symptoms in a small population of illicit drug users in the San Jose, Calif. area was linked to trace amounts of a toxic impurity in the home-synthesized drugs. Subsequent studies in animal models, including monkeys, demonstrated that 1-methyl-4-phenyl-1, 2,5,6-tetrahydropyridine (MPTP) was the cause of the Parkinson's-like symptoms which developed in the illicit drug users, as reported by J. W. Langston et al., in “Chronic Parkinsonism in Humans Due to a Product of Meperidine-Analog Synthesis” Science (Feb. 25, 1983) 219, 979-980. These early findings and the many studies that they stimulated led to the development of reliable models for Parkinson's disease, as reported by Heikkila, R. E., et al., in “Dopaminergic Neurotoxicity of 1-Methyl-4-Phenyl-1, 2,5,6-Tetrahydropyridine in Mice” Science (Jun. 29, 1984) 224:1451-1453; Burns, R. S., et al, in “A Primate Model of Parkinsonism. . . ” Proc. Natl. Acad. Sci USA (1983) 80:4546-4550; Singer, T. P., et al., “Biochemical Events in the Development of Parkinsonism. . .” J. Neurochem. (1987) 1-8; and Gerlach, M. et al., “MPTP Mechanisms of Neurotoxicity and the Implications for Parkinson's Disease” European Journal of Pharmacology (1991) 208:273-286. These references and others describe studies to help explain the mechanism of how the administration of MPTP to animals gives rise to motor defects characteristic of Parkinson's disease. They clearly indicate that MPTP was the cause of the Parkinson's-like symptoms that developed in the humans who had used the tainted illicit drugs and that similar motor deficits were found in other primates and other test animals which had been dosed directly with MPTP. They further point out that the administration of MPTP induces a marked reduction in the concentration of dopamine in the test subjects.
These findings have led to the development of an assay for agents effective in treating dopamine-associated neurodegenerative disorders, such as Parkinson's disease. In this assay, test animals are given an amount of MPTP adequate to severely depress their dopamine levels. Test compounds are administered to determine if they are capable of preventing the loss of dopamine in the test animals. To the extent that dopamine levels are retained, a compound can be considered to be an effective agent for slowing or delaying the course of neurodegenerative disease, e.g., Parkinson's disease.
Mitochondrial function is associated with many neurodegenerative diseases such as ALS, Huntington's disease, Alzheimer's disease, cerebellar degeneration, and aging itself (Beal, M. F. in Mitochondrial Dysfunction and Oxidative Damage in Neurodegenerative Diseases , R. G. Landes Publications Austin, Tex., 1995 at, for example, pages 53-61 and 73-99). Mitochondrial damage is the mechanism by which MPTP depletes dopamine concentrations in the striatum (Mizuno, Y., Mori, H., Kondo, T. in “Potential of Neuroprotective Therapy in Parkinson's Disease” CNS Drugs (1994) 1:45-46). Thus, an agent which protects from mitochondrial dysfunction caused by MPTP could be useful in treating diseases of the central nervous system in which the underlying cause is mitochondrial dysfunction.
While other benzamide compounds are known, their utility heretofore has generally been as intermediates in chemical syntheses or in fields unrelated to the present invention. Slight structural changes yielded large differences in efficacy and toxicity. The vast majority of benzamide compounds have little or no activity in our screens. However, there are reports of biological activity for other, structurally different benzamides. These reports include:
El Tayar et al., “Interaction of neuroleptic drugs with rat striatal D-1 and D-2 dopamine receptors: a quantitative structure—affinity relationship study” Eur. J. Med. Chem. (1988) 23:173-182;
Monković et al., “Potential non-dopaminergic gastrointestinal prokinetic agents in the series of substituted benzamides” Eur. J. Med. Chem. (1989) 24:233-240;
Banasik et al., “Specific inhibitors of poly(ADP-Ribose) synthetase and mono(ADP-ribosyl)transferase” J. Biol. Chem. (1992) 267:1569-1575;
Bishop et al., “Synthesis and in vitro evaluation of 2,3-dimethoxy-5-(fluoroalkyl)-substituted benzamides: high-affinity ligands for CNS dopamine D 2 receptors” J. Med. Chem. (1991) 34:1612-1624;
Högberg et al., “Potential antipsychotic agents. 9. Synthesis and stereoselective dopamine D-2 receptor blockade of a potent class of substituted (R)-N-[benzyl-2-pyrrolidinyl)methyl]benzamides. Relations to other side chain congeners” J. Med. Chem. (1991) 34:948-955;
Katopodis et al., “Novel substrates and inhibitors of peptidylglycine α-α-amidating monooxygenase” Biochemistry (1990) 22:4541-4548; and
Rainnie et al., “Adenosine inhibition of mesopontine cholinergic neurons: implications for EEG arousal” Science (1994) 263:689-690.
Other benzamide-containing pharmaceutical compositions and their use to treat or protect against neurodegenerative conditions were disclosed in commonly owned U.S. patent application Ser. No. 08/227,777 filed Apr. 14, 1994, the disclosure of which is incorporated herein by reference in its entirety.
STATEMENT OF THE INVENTION
It has now been found that a family of novel acetamidobenzamide compounds of the Formula I below exhibit strong activity against Parkinson's disease as measured by their ability to prevent MPTP-induced reduction of dopamine levels.
where R′ is a straight, branched or cyclic saturated all of from 3 to 5 carbon atoms and n is 1 or 2.
It has also been found that the novel nitro- and aminobenzamide compounds N-tert-amyl-4-nitrobenzamide (CPI1033), N-1,2-dimethylpropyl-4-nitrobenzamide (CPI1085), N-n-butyl-3-nitrobenzamide (CPI1135), N-n-pentyl-4-nitrobenzamide (CPI1140), N-2-methylbutyl-4-nitrobenzamide (CPI1146), N-n-butyl-3, 5-dinitrobenzamide (CPI1147), N-methylcyclopropyl-4-nitrobenzamide (CPI1164), N-n-butyl-2-nitrobenzamide (CPI1173), N-n-pentyl-2-nitrobenzamide (CPI1174), and N-methylcyclopropyl-4-aminobenzamide (CPI1240) are useful as intermediates for preparing the acetamide compounds of Formula I above and as pharmaceutical agents.
These nitro- and aminobenzamide compounds and the acetamidobenzamide compounds of Formula I constitute one aspect of the invention.
The invention can also take the form of pharmaceutical compositions based on one or more of the compounds of Formula II below:
where R′ is a saturated alkyl of from 3 to 5 carbon atoms, each R is independently —NH—CO—CH 3 , —NO 2 or —NH 2 , and n is 1 or 2, with the following provisos: 1) when n is 1 and R is —NO 2 at the 4 position of the ring, R′ is not tert-butyl, iso-butyl, or propyl; 2) when n is 1 and R is —NO 2 at the 2 position of the ring, R′ is not iso-butyl or propyl; and 3) when n is 2 and R′ is tert-butyl and both Rs are —NO 2 , the R groups are not at the 3 and 5 positions of the ring.
The invention can further take the form of methods of treating neurodegenerative conditions using these materials.
Thus, in one aspect this invention provides the novel acetamidobenzamide compounds of the Formula I and the novel nitro- and aminobenzamides described above.
In another aspect this invention provides pharmaceutical compositions which include one or more benzamide compounds of the Formula II in a pharmaceutically acceptable carrier. This carrier is preferably an oral carrier but can be an injectable carrier as well. These pharmaceutical compositions can be in bulk form but more typically are presented in unit dosage form.
In another aspect this invention provides a method for treating a patient suffering from a dopamine-associated neurodegenerative condition. This method involves administering to the patient an effective neurodegenerative condition-treating amount of one or more of the pharmaceutical compositions just described.
In another aspect this invention provides a method for treating a patient suffering from a condition characterized by progressive loss of central nervous system function. This method involves administering to the patient with loss of central nervous system function an effective amount of one or more of the pharmaceutical compositions just described.
In a most important aspect this invention provides a method for treating a patient suffering from a progressive loss of central nervous system function associated with Parkinson's disease. This method involves administering (preferably orally) to the patient with loss of progressive central nervous system function an effective amount of one or more of the pharmaceutical compositions just described.
In another aspect this invention provides a method for treating a patient suffering from a condition characterized by progressive loss of nervous system function due to mitochondrial dysfunction. This method involves administering to the patient with loss of central nervous system function an effective amount of one or more of the pharmaceutical compositions just described.
In a further aspect, this invention provides methods for preparing the compounds of Formula I and II. These methods generally involve condensing an alkyl amine of from 3 to 5 carbon atoms with a mono or dinitro benzoyl halide having the nitro configuration corresponding to the nitro, amine or acetamide substitution desired in the final compound, optionally, reducing the nitro groups, and, optionally, converting the amino benzamides to acetoamidobenzamides by reaction with an acetylhalide.
DETAILED DESCRIPTION OF THE INVENTION
The Compounds
This invention provides novel acetamidobenzamide compounds of the Formula I below and their use as active pharmaceutical agents.
where R′ is a saturated alkyl of from 3 to 5 carbon atoms and n is 1 or 2.
The acetamido group may be found anywhere on the ring. Preferred embodiments include when n is 1 and the R group is at the 2, 3 or 4 position of the ring and when n is 2 and the R groups are at the 2 and 3, 2 and 4, 2 and 5, 2 and 6, 3 and 4, or 3 and 5 positions of the ring.
With respect to the alkyl substituents, compounds wherein R′ is an alkyl which does not have a hydrogen on the alpha carbon, that is, the carbon which bonds to the nitrogen of the ring, are preferred. Examples of these preferred R′ groups are tert-butyl and tert-amyl.
The benzamide of the Formula I above which is N-tert-butyl4-acetamidobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1189.
The benzamide of the Formula I above which is N-iso-propyl-4-acetamidobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1232.
The benzamide of the Formula I above which is N-tert-amyl-4-acetamidobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1233.
The benzamide of the Formula I above which is N-tert-butyl-3-acetamidobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1234.
The benzamide of the Formula I above which is N-methylcyclopropyl-4-acetamidobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1241.
The compounds N-tert-butyl 4-acetamidobenzamide (CPI1189), N-iso-propyl-4-acetamidobenzamide (CPI1232), N-tert-amyl-4-acetamidobenzamide CPI1233), N-tert-butyl-3-acetamidobenzamide (CPI1234), and N-methylcyclopropyl-4-acetamidobenzamide (CPI1241) are the most preferred compounds of the Formula I at this time.
The invention also provides the following novel nitro- and aminobenzamide compounds which are useful both as intermediates in preparing the compounds of the Formula I and as active pharmaceutical agents: N-tert-amyl-4-nitrobenzamide (CPI1033), N-1,2-dimethylpropyl-4-nitrobenzamide (CPI1085), N-n-butyl-3-nitrobenzamide (CPI1135), N-n-pentyl-4-nitrobenzamide (CPI1140), N-2-methylbutyl-4-nitrobenzamide (CPI1146), N-n-butyl-3, 5-dinitrobenzamide (CPI1147), N-methylcyclopropyl-4-nitrobenzamide (CPI1164), N-n-butyl-2-nitrobenzamide (CPI1173), N-n-pentyl-2-nitrobenzamide (CPI1174), and N-methylcyclopropyl-4-aminobenzamide (CPI1240).
The benzamide which is N-tert-amyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1033.
The benzamide which is N-1,2-dimethylpropyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1085.
The benzamide which is N-n-butyl-3-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1135.
The benzamide which is N-n-pentyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1140.
The benzamide which is N-2-methylbutyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1146.
The benzamide which is N-n-butyl-3,5-dinitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1147.
The benzamide which is N-methylcyclopropyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1164.
The benzamide which is N-n-butyl-2-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1173.
The benzamide which is N-n-pentyl-2-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1174.
The benzamide which is N-methylcyclopropyl-4-aminobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI11240.
When the benzamide compound contains an amino group, such as CPI 1240, this functionality can be present as such or as a pharmaceutically acceptable salt. When these “compounds” are referred to it is to be understood that these salts are included as well.
Commonly owned U.S. patent application Ser. No. 08/227,777, referred to above, discloses several benzamides useful in treating neurodegenerative diseases based on their protective action in the MPTP mouse model of Parkinson's disease. The compound N-tert-butyl 4-acetamidobenzamide (CPI1189) of the present invention is an in vivo biotransformation product of one of these benzamides (N-tert-butyl 4-nitrobenzamide (CPI1020)) which is found in the blood of rats and mice to which CPI1020 has been administered orally. This compound is likely formed in the body by reduction of the ring nitro of CPI1020 to an amino moiety (CPI1160) followed by acetylation of the amino function.
The compounds of the present invention, as exemplified by CPI1189, are much more potent than CPI1020 (approximately 10 times as potent) in protecting mice from dopamine reduction in the striatum induced by s.c. treatment with MPTP. Based on structurally similar molecules such as acetaminophen which contain an acetamido functionality, they should also be safer than CPI1020 because they would not be metabolized in the body to result in metabolites containing hydroxylamines (likely to be Ames positive) nor would they be likely to result in amino metabolites which may have cardiovascular and/or anorexic effects.
Pharmaceutical Compositions
The benzamide compounds of the Formula II below:
where R′ is a straight or branched chain saturated alkyl of from 3 to 5 carbon atoms, each R is independently —NH—CO—CH 3 , —NO or —NH 2 , and n is 1 or 2, with the following provisos: 1) when n is 1 and R is —NO 2 at the 4 position of the ring, R′ is not tert-butyl, iso-butyl, or propyl; 2) when n is 1 and R is —NO 2 at the 2 position of the ring, R′ is not iso-butyl or propyl; and 3) when n is 2 and R′ is tert-butyl and both Rs are —NO 2 , the R groups are not at the 3 and 5 positions of the ring, are formulated into pharmaceutical compositions suitable for oral or other appropriate routes of administration.
The benzamide of the Formula II above which is N-iso-propyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1026.
The benzamide of the Formula II above which is N-tert-butyl-3-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1034.
The benzamide of the Formula II above which is N-tert-butyl-2-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1035.
The benzamide of the Formula II above which is N-n-butyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1045.
The benzamide of the Formula II above which is N-n-propyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1047.
The benzamide of the Formula II above which is N-tert-butyl-3,5-dinitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1049.
The benzamide of the Formula II above which is N-1-methylpropyl-4-nitrobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1084.
The benzamide of the Formula II above which is N-tert-butyl-4-aminobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1160.
The benzamide of the Formula II above which is N-tert-butyl-3-aminobenzamide is referred to elsewhere in this specification by the internal compound designation number CPI1248.
When R is —NH 2 , the compounds of the Formula II may be used as salts in which the amine group is protonated to the cation form, in combination with a pharmaceutically acceptable anion, such as chloride, bromide, iodide, hydroxyl, nitrate, sulfonate, methane sulfonate, acetate, tartrate, oxalate, succinate, or palmoate.
Pharmaceutical compositions using the compounds N-tert-butyl 4-acetamidobenzamide (CPI1189), N-tert-butyl-3-acetamidobenzamide (CPI1234), N-tert-amyl-4-acetamidobenzamide (CPI1233), N-tert-butyl-4-aminobenzamide (CPI1160), N-tert-butyl-3-nitrobenzamide (CPI1034), and N-tert-butyl-3-aminobenzamide (CPI1248) are most preferred at this time.
The compositions for oral administration can take the form of bulk liquid solutions or suspensions, or bulk powders. More commonly, however, the compositions are presented in a unit dosage form to facilitate accurate dosing. Typical unit dosage forms include prefilled, premeasured ampules or syringes of the liquid compositions or pills, tablets, capsules or the like in the case of solid compositions. In such compositions, the benzamide compound is usually a minor component (0.1 to say 50% by weight or preferably from about 1 to about 40% by weight) with the remainder being various vehicles or carriers and processing aids helpful for forming the desired dosing form. A liquid form may include a suitable aqueous or nonaqueous vehicle with buffers, suspending and dispensing agents, colorants, flavors and the like.
A solid form may include, for example, any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.
In the case of injectable compositions, they are commonly based upon injectable sterile saline or phosphate-buffered saline or other injectable carriers known in the art. Again the active benzamide is typically a minor component, often being from about 0.05 to 10% by weight with the remainder being the injectable carrier and the like.
These components for orally administrable or injectable compositions are merely representative. Other materials as well as processing techniques and the like are set forth in Part 8 of Remington's Pharmaceutical Sciences, 17th edition, 1985, Mack Publishing Company, Easton, Pa., which is incorporated by reference.
One can also administer the compounds of the invention in sustained release forms or from sustained release drug delivery systems. A description of representative sustained release materials can be found in the incorporated materials in Remington's Pharmaceutical Sciences.
Conditions Treated and Treatment Regimens
The conditions treated with the benzamide-containing pharmaceutical compositions may be classed generally as neurodegenerative conditions. These include conditions characterized by protracted low grade stress upon the central nervous system and gradual progressive loss of central nervous system function. These conditions include Parkinson's disease, amyotrophic lateral sclerosis (ALS, “Lou Gehrig's disease”), multiple sclerosis, Huntington's disease, Alzheimer's disease, diabetic retinopathy, multi-infarct dementia, macular degeneration and the like. Each of these conditions is characterized by a progressive loss of function. The benzamide compound-containing pharmaceutical compositions of this invention, when administered orally or by injection such as intravenously, can slow and delay and possibly even to some extent reverse the loss of function.
Injection dose levels for treating these conditions range from about 0.1 mg/kg/hour to at least 10 mg/kg/hour, all for from about 1 to about 120 hours and especially 24 to 96 hours. A preloading bolus of from about 0.1 mg/kg to about 10 mg/kg or more may also be administered to achieve adequate steady state levels. The maximum total dose is not expected to exceed about 2 g/day for a 40 to 80 kg human patient.
With these neurodegenerative conditions, the regimen for treatment usually stretches over many months or years so oral dosing is preferred for patient convenience and tolerance. With oral dosing, one to five and especially two to four and typically three oral doses per day are representative regimens. Using these dosing patterns, each dose provides from about 1 to about 20 mg/kg of benzamide, with preferred doses each providing from about 1 to about 10 mg/kg and especially about 1 to about 5 mg/kg.
Of course, one can administer the benzamide compound as the sole active agent or one can administer it in combination with other agents, including other active benzamide compounds.
Methods of Preparation of Compounds
The benzamide compounds of this invention can be prepared using commonly available starting materials and readily achievable reactions.
One representative preparation route, which is illustrated with tert-butyl amine, but which may be used with any alkyl amine, involves the following reactions:
where X is halo such as I, Br, F or Cl.
In step (A) the N-tert-butyl nitrobenzamides (III) are formed. This reaction must be carried out at temperatures below 10° C.
This step (A) yields as benzamides III, the compounds of the invention where R is —NO 2 .
In step (B) the nitro groups in the mono- or di-nitro benzamide III are subjected to reduction. This is commonly carried out with a reducing agent such as hydrazine and an appropriate catalyst such as a heterogeneous platinum, iron oxide hydroxide, palladium or nickel catalyst, typically on a support, or with hydrogen gas and a catalyst.
This step (B) yields as benzamides IV, the compounds of the invention where R is NH 2 .
In step (C) the amino-benzamides IV are converted to acetamidobenzamides V by reaction with an acetyl halide such as acetylchloride. This reaction is carried out in the presence of a mild base and at low to ambient temperatures such as −20° C. to +20° C. This yields the compounds of the invention where R is acetamido.
Alternate synthetic schemes may also be used to prepare the compounds of the present invention. Examples of these alternate routes are set forth below using CPI1189 as the representative compound. Other compounds may be prepared using these alternate methods by starting with appropriate starting materials, such as 2- or 3- amino- or nitro-benzonitrile or 2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5- diamino- or dinitro-benzonitrile and the appropriate alcohol (Alternate Route 1) or similarly substituted toluene compounds and the appropriate alkyl amine (Alternate Route 3).
Alternate Route 1
This route begins with acetylation of, for example, 4-aminobenzonitrile (A) to compound (B) using standard methods. Acid hydrolysis of tert-butanol in the presence of 4-acetamidobenzonitrile (B), provides a feasible synthetic pathway to CPI1189.
Alternate Route 2
Acetylation, using standard methods, of the inexpensive starting material PABA (C) affords a cheap method to produce 4-acetamidobenzoic acid (D). Conversion of (D) to the acid chloride (E) using standard methods (e.g., SOCl 2 ) and subsequent amidation using standard methods, such as those described previously, produces CPI1189 from inexpensive raw materials.
Alternate Route 3
Another method for the preparation of the compounds of the present invention begins with acetylation, using standard methods, of, for example, paratoluidine (F) to 4-acetamidotoluene (G). The synthetic intermediate (G) may be converted to 4-acetamidobenzoic acid (D) with common oxidizing agents (e.g., KMnO 4 ) and subsequently transformed to CPI1189 as outlined in Alternate Route 2.
EXAMPLES
The invention will be further described by the following Examples. These are provided to illustrate several preferred embodiments of the invention but are not to be construed as limiting its scope which is, instead, defined by the appended claims. Examples 1 to 19 demonstrate the preparation of acetamidobenzamides, as well as nitro- and aminobenzamides, which are representative of the benzamide compounds employed in the compositions and methods of this invention. Examples 20 to 24 demonstrate the preparation of pharmaceutical compositions based on the compounds. Thereafter biological test results illustrating the activity of the compositions of the invention are provided.
Example 1
Preparation of N-tert-butyl-4-aminobenzamide (CPI1160)
tert-Butyl amine (14.6 g, 0.200 mole) was stirred in ethyl acetate (150 mL, purified by washing with 5% sodium carbonate solution, saturated sodium chloride solution, drying over anhydrous magnesium sulfate, and filtering through fluted filter paper) and cooled to 5° C. with an ice bath. 4-nitrobenzoyl chloride (18.6 g, 0.100 mole) in purified ethyl acetate (75 mL) was added dropwise at such a rate to maintain the temperature below 10° C. The ice bath was removed upon complete addition of benzoyl chloride solution and the reaction stirred for 4 hours. The reaction mixture was then filtered on a Büchner funnel, the filtrate washed three times with 5 % HCl, once with saturated sodium chloride, dried over anhydrous magnesium sulfate, filtered through fluted filter paper, and the solvent stripped off leaving white crystalline product. The product was dried in a vacuum oven at 24 mm and 45° C. for 14 hours. This procedure produced 17.13 g of crystals of N-tert-butyl-4-nitrobenzamide (CPI1020) (77% yield), mp 162-163° C. Proton nuclear magnetic resonance (89.55 MHz in CDCl 3 ) showed absorptions at 8.257 ppm (d, 8.8 Hz, 2 H; 3,5-aryl H); 7.878 ppm (d, 8.8 Hz, 2 H; 2,6-aryl H); 6.097 ppm (bs, 1 H; N-H); 1.500 ppm (s, 9 H; tert-butyl H).
Palladium on carbon (5%, 75 mg) was added to CPI-1020 (5 g, 22.5 mmole) in 95% ethanol at 55° C. A solution of hydrazine (1.2 mL) in 95% ethanol (10 mL) was added dropwise over 30 min. and more Pd/C added (75 mg). The reaction was refluxed 3 hours, hydrazine (0.5 g) in 95% ethanol (5 mL) was added and the reaction was refluxed for another hour. The reaction was filtered on a buchner funnel, the volume of solvent reduced under vacuum, and extracted with dichloromethane. The combined extracts were dried over magnesium sulfate and solvent stripped, leaving 3.90 g of N-tert-butyl-4-aminobenzamide (CPI1160) (90% yield), melting point 125-127° C. 90 MHz proton NMR (in CDCl 3 ) showed absorbances at 7.290 ppm (2 H, d, 8.8 Hz; 2,6 aryl H); 6.368 ppm (2 H, d, 8.8 Hz; 3,5 aryl H); 5.45 ppm (1 H, bs; NHC═O); 3.727 ppm (2 H, bs; aryl-NH 2 ); 1.186 ppm (9 H, s; t-butyl H).
Example 2
Preparation of N-tert-butyl-4-acetamidobenzamide (CPI1189)
Acetyl chloride (0.45 g, 5.7 mmole) in ethyl acetate (25 mL) was added dropwise to CPI-1160 (1.0 g, 5.2 mmole) and triethyl amine (0.58 g, 5.7 mmole) in ethyl acetate at 3° C. at such a rate to maintain the temperature below 10° C. The reaction was allowed to warm to room temperature, stirred 1 hour, and washed with 5% HCl. Recrystallization from acetone gave 1.08 g N-tert-butyl-4-acetamidobenzamide (CPI1189)(89% yield), melting point 119-121 ° C. 90 MHz proton NMR (in DMSO-d6) showed absorbances at 9.726 ppm (1 H, bs, N—H); 7.715 ppm (4 H, dd, 4.4 Hz; aryl H); 7.295 ppm (1 H, bs; NH); 2.844 ppm (3 H, s; CH 3 CO); 1.448 ppm (9 H, s; t-butyl H).
Example 3
Preparation of N-tert-butyl-3-acetamidobenzamide (CPI1234)
The amidation procedures of Example 1 were followed using 3-nitrobenzoyl chloride instead of 4-nitrobenzoyl chloride. This gave N-tert-butyl-3-nitrobenzamide (CPI1034) in 92% yield, melting point 123-125° C. Proton NMR (in CDCl 3 ) showed absorptions at 8.517 ppm (2-aryl H, s, 1 H); 8.337 ppm ( 4 -aryl H, d, 8.8 Hz, 1 H); 8.121 ppm (6-aryl H, d, 6.4 Hz, 1 H); 7.618 ppm (5-aryl H, m, 1 H); 6.032 ppm (N—H, bs, 1 H); 1.484 ppm (t-butyl H, s, 9 H).
Iron (III) oxide hydroxide catalyzed hydrazine reduction produced N-tert-butyl-3-aminobenzamide (CPI1248) in 53% yield, melting point 118-120° C. Proton NMR (in CDCl 3 ) showed absorbances at 7.088 ppm (4-6-aryl H, m, 3 H); 6.794 ppm (2-aryl H, s, 1 H); 5.902 ppm (N—H, bs, 1 H); 3.145 ppm (aryl N—H, bs, 2 H); 1.458 ppm (t-butyl H, s, 9 H).
Acetylation of CPI1248 as described in Example 2 gave N-tert-butyl-3-acetamidobenzamide (CPI1234) in 75% yield, melting point 194-195° C. Proton NMR (in CDCl 3 ) showed absorptions at 7.778 ppm (4-6 -aryl H, m, 3 H); 7.392 ppm (2-aryl H, s, 1 H); 6.08 ppm (N—H, bs, 1 H); 2.174 ppm (acetyl CH 3 , s, 9 H); 1.500 ppm (t-butyl H, s, 9 H).
Example 4
Preparation of N-tert-butyl-2-acetamidobenzamide
The method of Example 3 is repeated using 2-nitrobenzoyl chloride in the amidation step. This yields N-tert-butyl-2-nitrobenzamide (CPI1035).
Reduction of the nitrobenzamide with hydrazine yields N-tert-butyl-2-aminobenzamide.
Acetylation of the aminobenzamide yields N-tert-butyl-2-acetamidobenzamide.
Example 5
Preparation of N-iso-propyl-4-acetamidobenzamide (CPI1232)
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and iso-propyl amine in the amidation step. This yields N-iso-propyl-4-nitrobenzamide (CPI1026).
Reduction of the nitrobenzamide with hydrazine yields N-iso-propyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-iso-propyl-4-acetamidobenzamide (CPI1232).
Example 6
Preparation of N-tert-amyl-4-acetamidobenzamide (CPI1233)
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and tert-amyl amine in the amidation step. This yields N-tert-amyl-4-nitrobenzamide (CPI1033).
Reduction of the nitrobenzamide with hydrazine yields N-tert-amyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-tert-amyl-4-acetamidobenzamide (CPI1233).
Example 7
Preparation of N-iso-butyl-4-acetamidobenzamide
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and iso-butyl amine in the amidation step. This yields N-iso-butyl-4-nitrobenzamide (CPI1044).
Reduction of the nitrobenzamide with hydrazine yields N-iso-butyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-iso-butyl-4-acetamidobenzamide.
Example 8
Preparation of N-n-butyl-4-acetamidobenzamide
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and n-butyl amine in the amidation step. This yields N-n-butyl-4-nitrobenzamide (CPI1045).
Reduction of the nitrobenzamide with hydrazine yields N-n-butyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-n-butyl-4-acetamidobenzamide.
Example 9
Preparation of N-n-propyl-4-acetamidobenzamide
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and n-propyl amine in the amidation step. This yields N-n-propyl-4-nitrobenzamide (CPI1047).
Reduction of the nitrobenzamide with hydrazine yields N-n-propyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-n-propyl-4-acetamidobenzamide.
Example 10
Preparation of N-1,2-dimethylpropyl-4-acetamidobenzamide
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and 1,2-dimethylpropyl amine in the amidation step. This yields N-1,2-dimethylpropyl-4-nitrobenzamide (CPI1085).
Reduction of the nitrobenzamide with hydrazine yields N-1,2-dimethylpropyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-1,2-dimethylpropyl-4-acetamidobenzamide.
Example 11
Preparation of N-n-pentyl-4-acetamidobenzamide
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and n-pentyl amine in the amidation step. This yields N-n-pentyl-4-nitrobenzamide (CPI1140).
Reduction of the nitrobenzamide with hydrazine yields N-n-pentyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-n-pentyl-4-acetamidobenzamide.
Example 12
Preparation of N-2-methylbutyl-4-acetamidobenzamide
The method of Example 3 is repeated using 4-nitrobenzoyl chloride and 2-methylbutyl amine in the amidation step. This yields N-2-methylbutyl-4-nitrobenzamide (CPI1146).
Reduction of the nitrobenzamide with hydrazine yields N-2-methylbutyl-4-aminobenzamide.
Acetylation of the aminobenzamide yields N-2-methylbutyl-4-acetamidobenzamide.
Example 13
Preparation of N-n-pentyl-2-acetamidobenzamide
The method of Example 3 is repeated using 2-nitrobenzoyl chloride and n-pentyl amine in the amidation step. This yields N-n-pentyl-2-nitrobenzamide (CPI1174).
Reduction of the nitrobenzamide with hydrazine yields N-n-pentyl-2-aminobenzamide.
Acetylation of the aminobenzamide yields N-n-pentyl-2-acetamidobenzamide.
Example 14
Preparation of N-tert-butyl-2,3-diacetamidobenzamide
The method of Example 3 is repeated using 2,3-dinitrobenzoyl chloride in the amidation step. This yields N-tert-butyl-2,3-dinitrobenzamide.
Reduction of the nitrobenzamide with hydrazine yields N-tert-butyl-2,3-diaminobenzamide.
Acetylation of the aminobenzamide yields N-tert-butyl-2,3-diacetamidobenzamide.
Example 15
Preparation of N-tert-amyl-2,4-diacetamidobenzamide
The method of Example 3 is repeated using 2,4-dinitrobenzoyl chloride and tert-amyl amine in the amidation step. This yields N-tert-amyl-2,4-dinitrobenzamide.
Reduction of the nitrobenzamide with hydrazine yields N-tert-amyl-2,4-diaminobenzamide.
Acetylation of the aminobenzamide yields N-tert-amyl-2,4-diacetamidobenzamide.
Example 16
Preparation of N-tert-butyl-2,5-diacetamidobenzamide
The method of Example 3 is repeated using 2,5-dinitrobenzoyl chloride in the amidation step. This yields N-tert-butyl-2,5-dinitrobenzamide.
Reduction of the nitrobenzamide with hydrazine yields N-tert-butyl-2,5-diaminobenzamide.
Acetylation of the aminobenzamide yields N-tert-butyl-2,5-diacetamidobenzamide.
Example 17
Preparation of N-tert-butyl-2,6-diacetamidobenzamide
The method of Example 3 is repeated using 2,6-dinitrobenzoyl chloride in the amidation step. This yields N-tert-butyl-2,6-dinitrobenzamide.
Reduction of the nitrobenzamide with hydrazine yields N-tert-butyl-2,6-diaminobenzamide.
Acetylation of the aminobenzamide yields N-tert-butyl-2,6-diacetamidobenzamide.
Example 18
Preparation of N-tert-butyl-3,4-diacetamidobenzamide
The method of Example 3 is repeated using 3,4-dinitrobenzoyl chloride in the amidation step. This yields N-tert-butyl-3,4-dinitrobenzamide.
Reduction of the nitrobenzamide with hydrazine yields N-tert-butyl-3,4-diaminobenzamide.
Acetylation of the aminobenzamide yields N-tert-butyl-3,4-diacetamidobenzamide.
Example 19
Preparation of N-tert-butyl-3,5-diacetamidobenzamide
The method of Example 3 is repeated using 3,5-dinitrobenzoyl chloride in the amidation step. This yields N-tert-butyl-3,5-dinitrobenzamide.
Reduction of the nitrobenzamide with hydrazine yields N-tert-butyl-3,5-diaminobenzamide.
Acetylation of the aminobenzamide yields N-tert-butyl-3,5-diacetamidobenzamide.
Preparation of Pharmaceutical Compositions
Example 20
The compound of Example 1 is admixed as a dry powder with a dry gelatin binder in an approximate 1:2 weight ratio. A minor amount of magnesium stearate is added as a lubricant. The mixture is formed into 240-270 mg tablets (80-90 mg of active benzamide) in a tablet press. If these tablets were administered to a patient suffering from a dopamine-associated neurodegenerative condition on a daily, twice daily or thrice daily regimen they would slow the progress of the patient's disease.
Example 21
The compound of Example 2 is admixed as a dry powder with a starch diluent in an approximate 1:1 weight ratio. The mixture is filled into 250 mg capsules (125 mg of active benzamide). If these capsules were administered to a patient suffering from a dopamine-associated neurodegenerative condition on a daily, twice daily or thrice daily regimen they would slow the progress of the patient's disease.
Example 22
The compound of Example 3 is suspended in a sweetened flavored aqueous medium to a concentration of approximately 50 mg/ml. If 5 mls of this liquid material was administered to a patient suffering from a dopamine-associated neurodegenerative condition on a daily, twice daily or thrice daily regimen they would slow the progress of the patient's disease.
Example 23
The compound of Example 4 is admixed as a dry powder with a dry gelatin binder in an approximate 1:2 weight ratio. A minor amount of magnesium stearate is added as a lubricant. The mixture is formed into 450-900 mg tablets (150-300 mg of active benzamide) in a tablet press. If these tablets were administered to a patient suffering from a dopamine-associated neurodegenerative condition on a daily, twice daily or thrice daily regimen they would slow the progress of the patient's disease.
Example 24
The compound of Example 14 is dissolved in a buffered sterile saline injectable aqueous medium to a concentration of approximately 5 mg/ml. If 50 mls of this liquid material was administered to a patient suffering from a dopamine-associated neurodegenerative condition such as Parkinson's disease on a daily, twice daily or thrice daily regimen this dose would slow the progress of the patient's disease.
It will be appreciated that any of the compounds of Formula II could be employed in any of these representative formulations, and that any of these formulations could be administered in any of these manners so as to treat any of the neurodegenerative conditions described in this specification.
Parkinson's Disease Screening Methods
Dopamine Depletion Studies.
C57BL/6J mice were pretreated with either vehicle (1% methyl cellulose) or a drug (p.o.) 30 min before MPTP. MPTP was dissolved in isotonic saline (0.9%) and given subcutaneously as a single dose of 15 mg free base/kg body weight to produce a reduction in striatal dopamine to about 0.5 nanomoles/mg protein. Groups of mice (n=8-10 per group) received either vehicle plus saline, vehicle plus MPTP, or drug plus MPTP. Seventy two hours after receiving MPTP, mice were sacrificed using cervical dislocation and the striata were excised. The tissue was homogenized in 0.4 N perchloric acid, centrifuged, and the supernatant analyzed by high performance liquid chromatography/electro-chemical detection (HPLC/ED) for dopamine levels. Supernatants were stored in a −90° C. freezer between the time of collection and analysis.
The drugs were combined with methyl cellulose and were homogenized in water for dosing. The dosage amount ranged from 10 to 50 mg/kg for CPI1160, CPI1189 and CPI1234, and from 50 to 100 mg/kg for CPI1020.
The results of representative experiments are provided in Tables 1 and 2. The results in Table 1 demonstrate that the compositions of this invention, as exemplified by CPI1160, CPI1189, and CPI1234 were effective in preventing dopamine depletion following MPTP challenge.
TABLE 1
Efficacy of CPI Compounds 1189, 1160, and 1234 at 30 mg/kg
in the 15 mg/kg MPTP Model.
NANOMOLES DOPAMINE PER
% NON-MPTP
COMPOUND
MG PROTEIN ± S.E.M.
CONTROL
methyl
0.72 ± .05
54.1
cellulose
CPI1160
1.25 ± .05
93.9
CPI1234
1.02 ± .05
76.7
methyl
0.56 ± .07
36.4
cellulose
CPI1189
1.37 ± .14
89.7
For comparison purposes the same tests were run on compositions based on CPI1020, a closely related benzamide compound. Results are shown in Table 2. At 50 mg/kg, CPI1189 offered complete protection from the neurotoxic action of MPTP (105% of control) while CPI1020 was not as effective (65% of control).
TABLE 2
Comparison of the Efficacies of CPI1189 and CPI1020 at 50
mg/kg in the 15 mg/kg MPTP Model.
NANOMOLES DOPAMINE PER
COMPOUND
MG PROTEIN ± S.E.M.
CPI1020
0.58 ± .14
CPI1189
1.57 ± .11
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A group of benzamide compounds are disclosed which are useful for treating neurodegenerative disorders. Methods for making these compounds are provided. These materials are formed into pharmaceutical compositions for oral or intravenous administration to patients suffering from conditions such as Parkinson's disease which can exhibit themselves as progressive loss of central nervous system function. The compounds can arrest or slow the progressive loss of function.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 60/215,447, filed on Jun. 30, 2000.
TECHNICAL FIELD
The present invention relates generally to database systems. More particularly, the present invention relates to a system and method for storing and accessing data in data cells.
BACKGROUND OF THE INVENTION
Current database technology generally relies on one of three main types: relational databases, object-oriented databases, or a combination of relational and object-oriented databases. Relational databases divide the world into tables, with columns defining data fields and rows defining data records. Relational databases then use relationships and set theory to model and manage real-world data. Object-oriented databases model the world in objects, in which data is encapsulated into objects and associated with methods and procedures. Object-relational databases are a combination of the previous two types.
All of these database constructs are primarily concerned with organizing data into predefined formats and structures. In order to represent the data, an object or a table must be defined with known data characteristics. For instance, before data can be stored in an object, the object must be defined to allow certain types of data, and the object must be pre-associated with relevant procedures. Alternatively, in the relational database construct, a table must be defined before any data can be stored in the table, with each column being defined to allow only certain amounts and types of data.
Unfortunately, this pre-defining of data is always done without a perfect knowledge of the real-world data being modeled. As a result, once the database is actually implemented, changes often must be made to the table definitions or objects so as to more accurately reflect the real-world data. These changes will typically require that the database be reconstructed according to the new definitions. In addition, even after an optimum definition of the real-word data is created, the existing database constructs are not flexible enough to handle unique situations that do not fit the optimum definition. Once this definition is created, along with the related data formats, relationships, and methods, the created structure cannot be easily modified to allow the representation of the unusual case.
What is needed is a database construct that is not as rigid as the existing models of relational and object-oriented databases. This preferred model would not require a pre-definition of the data, but would rather allow data to be entered as it is encountered. Associations between data elements could be developed on-the-fly, and new data could be added to the system even if the pre-existing model did not expect such data to exist.
SUMMARY OF THE INVENTION
The present invention meets the needs and overcomes the associated limitations of the prior art by storing data in cells. A data cell contains only a single element of data. By storing all data in these cells, data can be dynamically structured according to changing needs. In addition, the information stored in the cell is easily accessible, meaning that data extrapolation is quick and easy. Additional references to a particular data value will always use the one data value that has been dynamically normalized by the present invention. Finally, meta data that defines data structures and types are stored in data cells, which allows the data collection to be self-defining.
The data cell of the present invention includes four elements: an Entity Instance Identifier (identified in this application through the letter “O”), an Entity Type Identifier (“E”), an Attribute Type Identifier (“A”), and an Attribute Value (“V”). For instance, the existence of an employee who is named “Johnson” would be represented by a single cell. The Entity Type Identifier would be an “Employee.” The Entity Instance Identifier is an identifier, such as the number “1,” that allows the employee to be uniquely identified. The Attribute Type Identifier would be the “Employee Name,” and the Attribute Value would be “Johnson.” The data cell would look like the following:
O
E
A
V
1
Employee
Employee Name
Johnson
Groups of cells with identical O and E values constitute a cell set, and contain information about a specific instance of an entity. Every cell contains a unique combination of O, E, A, and V, meaning that each cell is unique within any particular information universe.
Relationships between cells and cell sets are created through the use of “linking” or “synapse” cells. Synapse cells are created through a process of transmutation. In transmutation, two cell sets are associated with each other through the creation of two synapse cells. The first synapse cell has the O and E values of the first cell set, and has an A and V value equal to the E and O value, respectively, of the second cell set. The second synapse cell has the O and E values of the second cell set, and has as its A and V values the E and O value, respectively, of the first cell set.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prior art database table showing a sample representation of employee data in a relational database system.
FIG. 2 is a prior art database table showing a sample representation of project data in a relational database system.
FIG. 3 is a prior art database table showing a sample representation of relationship data in a relational database system.
FIG. 4 is a schematic illustration of a cell of the present invention showing the four components of a data cell.
FIG. 5 shows an example data cell.
FIG. 6 is a cell listing of present invention data cells containing the data stored in the tables shown in FIGS. 1 and 2 .
FIG. 7 is a cell listing showing three cells that can be added to the cell set list.
FIG. 8 is a schematic drawing showing the first stage of transmutation to create a synapse cell linking an employee cell set with a project cell set.
FIG. 9 is a schematic drawing showing the second stage of transmutation to create a second synapse cell linking a project cell set with an employee cell set.
FIG. 10 is a cell listing showing a portion of the data cells shown in FIG. 6 along with the synapse cells setting forth the relationships found in FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
1. Prior Art
FIGS. 1 through 3 show three relational tables as would be used in the prior art. The first table 10 shown in FIG. 1 contains employees. There are four columns in this table 10 , namely employee name 12 , social security number 14 , address 16 , and salary 18 . These columns 12 , 14 , 16 , and 18 define the different types of data that can be contained in table 10 . Table 10 also contains three rows 20 of data. Each row 20 contains information about a different employee in the table 10 . Data values for a relational data table such as table 10 are determined by finding the field that exists at the cross section between a particular row 20 and a particular column 12 , 14 , 16 , or 18 .
Similarly, the second table 40 shown in FIG. 2 contains information about projects that employees might work on for their employer. The projects table 40 shown in FIG. 2 contains only two columns, namely a project name column 42 and a project size column 44 . The projects table 40 contains information about three projects, and therefore the table contains exactly three rows 46 .
It is often important in databases to model the fact that some data is associated with other data. In the example of employees and projects, as shown in FIGS. 1 and 2 , the database should show that certain employees work on certain projects. If only one employee can be assigned to a project, it would be possible to associate an employee with a project simply by adding an employee column to the project table 40 . Similarly, if each employee were assigned only to a single project, a project column in the employee table 10 would serve to make the association.
However, in the real world, it is likely that each project will have more than one employee assigned to it, and it is likely that each employee will be assigned to more than one project. To handle the possibility of these types of many-to-many relationships, it is necessary to utilize a third table 60 , such as that shown in FIG. 3 . This third table 60 contains only two columns, namely project name 62 and employee name 64 . The project name column 62 contains the same type of information as the project name column 42 in table 40 . Likewise, employee name column 64 contains the same information as employee name column 12 of table 10 . Each row 66 represents a relationship between a row 20 in table 10 (i.e., an employee) and a row 46 in table 40 (i.e., a project). Thus, table 60 shows that the Red project has two employees working on it, namely Johnson and Anderson, while the Yellow and Green projects have only a single employee assigned to them, namely Rodriguez.
Very often, relational databases utilize key fields to aid in data access. The data in a key field must be unique for the entire table. Thus, a key field for the employee table 10 might be the social security number column, since the U.S. government strives to ensure that each social security number is unique to one individual. In project table 40 , it might be wise to create a project number column that is subject to a uniqueness constraint to ensure that no two rows 46 contain the same project number. The key fields are then pre-indexed, which allows fast access to data in a table when the key field is known. These key fields can then be used to create efficient relationships in a table such as table 60 .
2. Data Cells
The present invention differs from traditional relational and object-oriented databases in that all data is stored in data cells 100 . In its most generic sense, a data cell 100 is a data construct that contains a single attribute value. In comparison to a relational database table, a single data cell would contain the value of a field found at a single column and row intersection. The data cell 100 of the present invention differs from an intersection in a data table in that the data cell 100 is not stored within a table or an object construct. Because there is no external construct to associate one cell 100 with another, each data cell 100 of the present invention must be self-identifying. In other words, the data cell 100 must contain not only the value of interest, but it also must contain enough information to identify the attribute to which the value relates, and to associate the attribute with a particular instance of an entity.
As shown in FIG. 4 , the preferred embodiment of a data cell 100 utilizes four fields: an Entity Instance Identifier 102 , an Entity Type Identifier 104 , an Attribute Type Identifier 106 , and an Attribute Value 108 . These four fields 102 , 104 , 106 , and 108 are also identified by the one letter titles “O,” “E,” “A,” and “V,” respectively.
The O field 102 is the Entity Instance Identifier, and serves to uniquely identify the entity that is associated with the data cell 100 . The E field 104 is the Entity Type Identifier, which identifies the type of entity associated with the cell 100 . The O field 102 and the E field 104 together uniquely identify an entity in an information universe. An information or data universe is defined as the complete collection of data cells 100 that exist together. All cells 100 with the same O field 102 and E field 104 within an information universe are considered part of the same cell set 101 . All cells 100 within a cell set 101 are used to store data and relationships about the particular entity instance identified by the combination of the O and E fields 102 , 104 .
The A or Attribute Type Identifier field 106 indicates the type of information found in the cell 100 . Finally, the V or Attribute Value field 108 contains the actual real-world information that is found in the cell 100 . The data in V 108 can be of any type, including a character string, a number, a picture, a short movie clip, a voice print, an external pointer, an executable, or any other type of data.
Each cell 100 contains one unit or element of information, such as the fact that a particular employee makes $ 50 , 000 per year. The data cell 100 that contains this information might look like that shown in FIG. 5 . The O field 102 contains the phrase “Object ID,” which indicates that the O field 102 contains some type of identifier to uniquely identify the employee that has this salary. In the preferred embodiment, the object identifiers in the O field 102 are integers. The E field 104 of FIG. 5 indicates that the type of entity that this cell 100 applies to is an employee. The A field 106 shows that this cell 100 describes the salary attribute. Finally, the V field 108 contains the actual, real-world data for the cell 100 , namely the $ 50 , 000 salary.
FIG. 6 shows the data found in FIGS. 1 and 2 in the form of data cells 100 of the current invention. For each employee in table 10 , the four columns 12 , 14 , 16 , and 18 of data are embodied in four separate data cells 100 . The data for the employee named Johnson are found in the first four data cells 100 in FIG. 6 . Since these first four data cells 100 all contain the same O and E values, these cells 100 form a cell set 101 . More specifically, the O field 102 and E field 104 indicate that this first cell set 101 contains information about instance number “1” of an entity of type “Employee.” The A fields 106 of these four cells 100 represent the four attributes for which data has been stored, namely Employee Name, Social Security, Address, and Salary. The V fields 108 holds the actual values for these attributes.
An examination of FIGS. 1 , 2 , and 6 reveals that all of the information stored in tables 10 and 40 has been replicated in individual data cells 100 of FIG. 6 . In FIG. 1 , the employee Anderson has no salary value in column 18 . Thus, the second cell set 101 in FIG. 6 contains only three cells 100 , since no cell 100 is needed to represent that fact that no information is known about Anderson's salary. This differs from relational database table of FIG. 1 , where each column 12 , 14 , 16 , and 18 must exist for all employee rows 20 , even in cases where no value exists and the field simply sits empty.
Moreover, this flexibility makes it possible to have additional cells 100 for some cell sets 101 that do not exist in other cell sets 101 . FIG. 7 shows three possible additional cells 100 that relate to the employee named “Johnson.” With the flexibility of the cell-based data structure of the present invention, it is possible to add cells 100 such as those shown in FIG. 7 on the fly. There is no need to restructure the database to allow such new information, as would be required if new information were to be tracked in a prior art relational or object oriented database.
3. Transmutation
As shown in FIG. 3 , an association between the employee named Johnson and the project named Red is created in a relational database by creating a row 66 in a relationship table 60 . An association between cells 100 and/or cell sets 101 can also be created in the cell-based data structure of the present invention. This is accomplished through the use of special types of cells known as synapse cells 110 .
Synapse cells 110 are created through a process known as transmutation, which is illustrated in FIGS. 8 and 9 . FIG. 8 shows two conventional cells 100 , the first belonging to the cell set 101 relating to the employee named Johnson, and the second belonging to the cell set 101 relating to the Red project. The synapse cell 110 that establishes an association between these two cell sets 101 is created by making a new synapse cell 110 based upon the values of cells 100 from the two cell sets 101 . The new synapse cell is given the same O 102 and E 104 values of the first cell set 101 , in this case the values “1” and “Employee.” The A 106 and the V 108 values of the synapse cell 110 are taken from the E 104 and the O 102 values, respectively, of the second cell 100 . This “transmutation” of the existing cells 100 into a new synapse cell 110 is represented in FIG. 8 by four arrows.
The association of the two cell sets 101 is not complete, however, with the creation of a single synapse cell 110 . This is because every association created in the present invention is preferably a two-way association, and therefore requires the creation of a second synapse cell, as shown in FIG. 9 . This second synapse cell 110 is created using the same O 102 and E 104 values as that of the second cell 100 . The A 106 and the V 108 values of this second synapse cell 110 are taken from the E 104 and the O 102 values, respectively, of the first cell 100 being associated. The transmutation into the second synapse cell 110 is shown by the arrows in FIG. 9 .
When the two synapse cells 110 shown in FIGS. 8 and 9 have been created, then the association between the cell sets 101 has been completed. FIG. 10 shows the cell listing of FIG. 6 , with the first and last cells 100 of FIG. 6 surrounding vertical ellipses that represent all of the other cells 100 of FIG. 6 . In addition to the cells 100 of FIG. 6 , the cell listing of FIG. 10 includes the synapse cells 110 that are needed to represent the relationships shown in table 60 of FIG. 3 . It is clear that each synapse cell 110 has a partner synapse cell 110 that shows the same association in the opposite direction. Thus, eight synapse cells are used to represent the four relationships shown in table 60 of FIG. 3 .
The synapse cells 110 are generally treated the same as other cells 100 that exist in a data universe. Occasionally, it is useful to be able to know whether a particular cell 100 contains actual data, or is a synapse cell 110 . In the present invention, this is accomplished by associating a value, bitmap, or other flagging device with each cell 100 in the data universe. By examining this value, it would be possible for a database management system to immediately determine whether the cell 100 is a synapse cell 110 or contains real-world data.
The terms synapse and cell are used in this description to allude to the similarity between the present invention and the way that the human brain is believed to store memories. When the brain encounters new data, the data is stored in the brain's memory cells. The brain does not pre-define the data into tables or objects, but rather simply accepts all data “on-the-fly” and puts it together later.
Research has shown that the synapses in the brain hook cells together. Where synapse pathways are more frequently traversed in the brain, those pathways become thicker or are connected with more synapses. As a result, these connections become stronger. At the same time, other connections can be formed in the brain that can be loose or incorrect. Yet these memory errors to not corrupt the database of the brain. Rather, the brain is constantly checking associations for validity, and correcting those associations as needed.
This is similar to the present invention. Data is encountered and placed into data cells 100 . There is no need to predefine tables or objects before a new source of data is encountered. New cells 100 are simply created as needed. Synapse cells 101 can be formed between those data cells 100 on the fly. The associations that are represented by these synapse cells 101 can be strong or week, and be broken as needed without altering the structure of the database.
4. Conclusion
The above description provides an illustrative version of the present invention. It should be clear that many modifications to the invention may be made without departing from its scope. For instance, it would be possible to include only some of the elements of the present invention without exceeding the essence of the present invention. Therefore, the scope of the present invention is to be limited only by the following claims.
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A method and system is presented for storing data in data cells containing only a single element of data. Each data cell includes four components: an Entity Instance identifier (“O”), an Entity Type identifier (“E”) an Attribute Type identifier (“A”), and an Attribute Value (“V”). Groups of cells with identical O and E values constitute a cell set. Every cell contains a unique combination of O, E, A, and V. Relationships between cell sets are established by creating two synapse cells. The first synapse cell has O and E values of the first cell and has A and V values equal to the E and O value, respectively, of the second cell. The second synapse cell, has O and E values of the second cell, and has as its A and V values the E and O value, respectively, of the first cell set.
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BACKGROUND OF THE DISCLOSURE
In drilling a well, the drill string is connected with the drill bit as the hole is deepened. Occasionally, the hole will deviate and form what is known as a key seat which tends to stick the pipe. At other times, there will be a failure of the drill string where the pipe is broken with part of the drill string retrieved, part of the drill string in the hole. In other instances, differential pressure sticking will grab and hold the drill string, often relieved by removing part of the drill string and leaving the lower end of the drill string in the hole. In a variety of circumstances exemplified by those listed above, it is sometimes necessary to remove the drill string, leaving a part of the drill string in the hole and thereafter conduct a washover operation. In doing this, a larger diameter pipe is lowered into the borehole and is stabbed over the remaining portion of the drill string which was left in the borehole. This portion is commonly known as a fish, and one procedure for removing the fish is a washover process. In washover, the drill string is removed and repositioned in the borehole with a large diameter pipe at the lower end. The wash pipe diameter is sufficient to telescope over the stuck fish. A large flow of drilling fluid is then introduced through the drill string and the wash pipe while rotating with weight on the drill string. The wash pipe is advanced to telescope over the fish. This washover will typically release the stuck fish and thereby free it so that the fish can then be retrieved from the borehole.
A successful washover job requires a large flow of fluid. The drilling fluid flow is almost unimpeded when the washover pipe is clear of obstructions. By contrast, the drilling fluid flow is impeded when going in the hole, if the wash pipe OD has little clearance in the well borehole, or if the OD of the fish has little clearance from the ID of the wash pipe when it is engaged. Both of these conditions tend to divert the flow of fluid up the drill string. This action will cause the drill pipe to overflow at the surface, and also will retard lowering the string into the well borehole because of the piston action created by the restricted fluid flow.
Successful washover operations do require a substantial flow delivered to the right portion of the borehole to complete a washover job. Consider as an example a 500' fish which is stuck in a key seat. Assume that the key seat is approximately half the length of the fish. The washover pipe is run into the well to extend over the stuck fish. Assume in this example that the drill bit forms a hole which is approximately 7 inches in diameter while the drill pipe of the fish is typically 4 1/2 or 5 inches OD. This leaves little clearance for the wash pipe to pass over the stuck fish. When the wash pipe telescopes over the drill pipe in the borehole, the stuck fish tends to plug the wash pipe thus forcing the fluid up the drill sting causing the drill string to over flow at the surface, impeding the process of lowering the string in the hole.
This apparatus is installed in a drill string at the top end of the wash pipe. It vents drilling fluid while the wash pipe is being stabbed into the borehole while it telescopes over the stuck fish. When the wash pipe is partially obstructed by the stuck fish partly in the bottom end of the wash pipe, the wash pipe is pushed onto the fish until such obstruction forces drilling mud in the well up the drill string. perhaps to spill on the rig floor. The present apparatus responds to this increase in pressure and bypasses drilling mud through ports isolated by a movable sleeve. The bypass route opens into the annular space above the wash pipe. The wash pipe may pass over the stuck fish without overflowing at the top end of the drill string. When the pump is turned on the sleeve is moved to close the ports and the flow from the pump is then directed to the bottom end of the wash pipe. This delivers the washover fluid at the location where it is most needed. This enables a more rapid retrieval of the fish in that the washover procedure is expedited; also, the rig floor is kept clean.
The method and apparatus of the present disclosure are thus summarized as providing a wash pipe for attachment to the lower end of a drill string to be run into a borehole to undertake a washover operation. The washover pipe is connected with the drill string thereabove by means of a tubular member which provides diametric transition as necessary between the larger wash pipe and the smaller drill string thereabove. On the interior, there is a lengthwise sleeve. In the up position, it aligns ports through the sleeve with ports in the outer wall. This serves as a bypass for drilling fluid forced upward through the drill string, thereby reducing the washover fluid flowing through the drill string to the surface. The sleeve is forced upwardly by means of a coil spring or collet spring. A restricted orifice at the top end of the sleeve makes it responsive to an increase in pump pressure. Where there is an increase in supply pressure and hence pressure drop across the restriction, the restriction and connected sleeve is then forced downwardly. There is also an unbalanced piston (pressure down) to help force the sleeve over the ports should the flow be restricted sufficiently to cause the restriction not to activate. When it moves downwardly, it closes off the ports in the sleeve, achieving an isolation by suitable seals and thereby preventing use of the bypass route for the washover fluid. The device preferably includes a latch mechanism which secures it in the down or closed position of the sleeve. An alternate embodiment is also disclosed.
A procedure contemplating washover assistance of fish retrieval is set forth. All of this will be detailed in greater detail on review of the present disclosure.
DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 shows a washover pipe on a drill string for retrieving a fish in a borehole, the present apparatus being connected between the washover pipe and the drill string;
FIG. 2 is an elongate sectional view through the washover circulating valve of the present disclosure further including details of construction of the drill string thereabove and wash pipe therebelow;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2 showing details of construction of bypass ports for bypassing washover fluid; and
FIG. 4 is a sectional view through the present apparatus showing a spline arrangement to align ports in a movable sleeve with ports in the surrounding sleeve;
FIG. 5 is a view similar to the view of FIG. 2 showing a restricted orifice connected with the sleeve wherein the sleeve and orifice have moved downwardly in response to pressure differential to change the bypass flow route for washover fluid;
FIG. 6 is a sectional view similar to FIG. 2 through an alternate embodiment again showing a sleeve with ports therein relative to communicating ports to define washover fluid bypass;
and
FIG. 7 is a view of the same structure shown in FIG. 6 wherein the sleeve has moved downwardly in response to pressure differential to close off the bypass route for washover fluid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is first directed to FIG. 1 of the drawings where a washover procedure will be first described. Thereafter, the washover circulating valve of this disclosure will be incorporated with the structure shown in FIG. 1.
Assume in FIG. 1 that an open hole has been drilled to a specified depth. The hole is identified by the numeral 10. A fish 11 is stuck in the borehole. The fish 11 can be long or short. It can be made by unthreading the upper portion of the drill string, thereby leaving a open box connection at the top end of the fish. Alternatively, it can be formed by twisting off the pipe, typically a situation in which significant damage may occur. Whatever the cause, the fish 11 is of substantial length and includes the stuck portion of pipe and drill bit, some drill collars and drill pipe. The length of the pipe can be varied over a wide range. The pipe is stuck by means of a key seat, one such key seat being exemplified at 12. It can be stuck for other reasons also.
In a retrieval procedure, a portion of the drill string is retrieved. It is run back into the borehole 10. The upper portion of the drill string is identified by the numeral 13. It connects at the bottom with a wash pipe 14. The wash pipe 14 is larger diameter. It is sized so that it will telescope over the stuck fish. The washover pipe 14 is joined to the drill string by means of the circulating valve assembly 15 of this disclosure.
The present apparatus thus connects between the drill string and the wash pipe to provide two fluid flow paths. One fluid flow path is through a set of bypass passages to the larger annular area above the wash pipe. It will be observed in FIG. 1 that the wash pipe 14 telescopes over the stuck fish as a means of retrieving and freeing the fish.
Attention is next directed to FIG. 2 of the drawings which shows the apparatus of the present disclosure. At the upper end, it is provided with a conventional threaded box 16 which is formed in accordance with conventional industry standards. The box threads are formed in the outer tubular member 17. Typically, the tubular member 17 is substantial length and extends downwardly with a central axial passage 18. The passaage 18 has an internal shoulder 19 which faces downwardly. The shoulder 19 abuts the upper end of a movable sleeve 20. The sleeve 20 telescopes on the interior of the tubular member 17. The sleeve 20 is equipped with a seal member 21 at the upper end. A similar seal member 22 is spaced therefrom, the seal members defining a region where fluid communication on the exterior is forbidden. A pressure relief hole 23 is drilled through the tubular sleeve to introduce fluid flow to the interior of the tubular member 17 for pressure equalization purposes.
The device is pressure responsive. This is accomplished by positioning a restrictive orifice or ring 25 at the top end of the sleeve. It fits adjacent the shoulder 19 which limits upward travel of the sleeve 20. Moreover, the restrictive orifice is sized so that in conjunction with the cross sectional area of the passage 18 and the obstruction placed in the wash pipe as will be described, restriction creates an increase in pressure drop. This increase in pressure drop creates an increased pressure forcing the sleeve 20 downwardly. To aid in closing there is an unbalanced piston (pressure down) so the ports will close even if the flow restriction below negates the action of the restrictive orifice. The sleeve is normally held in an up position by means of a compressed spring coil 24. The spring 24 bears against the sleeve. The spring 24 shown in the elongated condition in FIG. 2 while it is compressed in FIG. 5. Operation of the device will be set forth to explain how this operates. As shown in FIG. 2, the sleeve 20 is equipped with a set of internal ports or passages 26. The ports are drilled through the sleeve to provide an alternate fluid flow path. There are several ports. They are aligned with a set of matching passages or ports 27 which are formed through the tubular member 17. When aligned, the several ports collectively provide an aggregate cross sectional area flow path which is sufficient to deliver all the fluid flow to the exterior of the wash pipe in the event the axial flow path is completely closed. In the position of the sleeve in FIG. 2, the ports are aligned. This up position enables fluid to bypass through the bypass route as will be explained when operation is described. The bypass route is assured by aligning the ports 26 with the ports 27. Thus, vertical alignment is achieved by locating the two sets of ports such that the sleeve is at its upper extremity of movement abutted against the shoulder 19. Rotational alignment is also accomplished by a means to be described to assure that the individual ports line up also to enable a substantial fluid flow path to be provided. The several ports are protected against leakage to the exterior of the sleeve by means of the seal member 22 previously defined and a cooperative seal ring 28. The seals 22 and 28 fully surround the tubular member 20 and isolate against leakage to the exterior of the sleeve.
Proceeding on downwardly with this structure as shown in FIG. 2, the ports 27 open at an external shoulder where the tubular member 17 is larger. This larger portion is indicated generally by the numeral 30. The larger diameter portion 30 is cooperative with an extension sleeve 32 which is joined at a set of threads 31. The threaded connection permits the extension sleeve to be taken apart for servicing of the components on the interior of the apparatus 15. The sleeve 20 terminates at an outwardly directed set of spline teeth 35. The teeth align with cooperative teeth at 36. This is perhaps better shown in the sectional view of FIG. 4 where the spline teeth 35 are illustrated. They mesh with and telescope into the cooperative spline teeth 36.
The sleeve 20 is made in multiple components, there being a threaded connection at 37 with a continuation sleeve 38, and this is also shown in FIG. 4. The sleeve 38 is surrounded with the coil spring 24 which bears against the spline teeth 35 attached to the sleeve. Moreover, the sleeve 38 which serves as an extension has an enlargement 40 which comprises an upwardly facing shoulder. This is formed on the exterior as used in a latching mechanism. The sleeve 38 has a passage formed therein at 41, the passage serving as a pressure equalization pathway to prevent pressure build up on the interior of the tool but on the exterior of the telescoping sleeve. The outer sleeve 32 extends downwardly to a threaded connection at 43 and joins with another tubular member which is the washover pipe 14. This can be quite long. It can be formed in one or more sections as required. At the threaded connection between the two, an internal lock ring 44 is captured. The lock ring 44 holds in position a bottom sub 45. The sub 45 fits around the telescoping sleeve 20 and the extension sleeve 38. It has an axial passage which permits downward movement of the sleeve on the interior at least until the movement is limited by an upwardly facing internal shoulder 46. The shoulder 46 limits the travel of the telescoping sleeve for reasons to be described. The sub 45 is captured in position. It is on the interior of the structure with an upwardly facing shoulder which receives a thrust ring 47. The thrust ring has a elongate upwardly extending sleeve portion which is shaped into a set of collet fingers 48. The collet fingers are thus split lengthwise to define individual fingers, and they all are equipped with latching undercut shoulders which engage the shoulder 40. In the contrast found between FIGS. 2 and 5, the collet fingers are latched to hold the sleeve downwardly. The collet fingers are smaller in diameter and fit within the coil spring 24. They are sized so that the coil spring can be compressed around them. Moveover, the several collet fingers are used to hook or latch onto the sleeve to hold it in the down position. The enlargement 48 thus has a tapered shoulder encouraging the collet fingers to ride gently over and reach into a latching position.
Operation of the telescoping sleeve shown in FIG. 2 should be explained. As long as the pressure drop caused by the restriction 25 is nominal, the sleeve is held upwardly in the illustrated position of FIG. 2. It is retained in this position by the coil spring 24 which creates a force overcoming the downward force acting at the restriction 25. When the pump pressure is increased, and the pressure drop across the restriction 25 increases, the sleeve 20 is forced downwardly by the force created by the flow. Even if fluid flow is nil as a result of a downhole obstruction, the sleeve will close because it is an unbalanced piston. The upper end of the sleeve has a larger surface area than the lower end of the sleeve. Therefore, if flow is too low to operate the restrictive orifice by creating a downward force, the sleeve is forced downwardly by pressure acting on the uneven end areas. Downward travel is limited by the shoulder 46. Downward movement of the sleeve 20 is thus normally initiated by pressure differential acting at the restriction 25 at the upper end of the sleeve. Another force driving the sleeve downwardly is obtained from pressure acting on the unbalanced piston which results from an area differential. Before it moves, the bypass arrangement through the ports 26 and the passages 27 is open, thereby deflecting mud flow to the exterior. On sufficient pressure differential across the restriction 25, the sleeve 20 is forced downwardly. As noted, it travels downwardly until limited by the shoulder 46. As it moves downwardly, the several collet fingers 48 deflect outwardly and latch over the shoulder 40. This is accomplished while compressing the spring 24. FIG. 5 shows the collet fingers latched and holding the sleeve in the downward position. This lock arrangement serves to hold the sleeve in the down position of FIG. 5. The bypass route is closed and sealed by the seal ring 22 which is now interposed between the ports 26 and the passages 27. In this arrangement, no additional fluid can flow out through the bypass. This assures that the fluid is fully transferred along the drill string and directs total flow around the rotary shoe which is typically attached at the bottom of the wash pipe. This delivers the mud flow out through the wash pipe and rotary shoe for conducting a wash operation. At this point, drill string manipulations can then be undertaken to force the wash pipe further into the borehole, washing at the rotary shoe on discharge of the mud flow to free the fish, and ultimately accomplish unsticking of the fish.
An alternate embodiment is illustrated in FIGS. 6 and 7. This device is indicated generally by the numeral 50. In the apparatus, it again has a telescoping sleeve 52 with a restriction 53 at the upper end. Several lugs 51 aligned with slots at the upper end of the sleeve 52 prevent rotation to assure port alignment. The sleeve is penetrated by several ports 54 which open to the exterior. The several ports align with passages 55 which complete the bypass route. Moreover, the exterior of the structure is enlarged at 56 to define a thicker portion, enabling a threaded connection at 57 with a sleeve extension member 58. The sleeve 58 extends downwardly to a sub 59 which terminates at a conventional threaded pin 60. The pin 60 is selected to match the exposed box on the top end of the stuck fish to implement retrieval. The sub 59 has a threaded exterior which permits connection with a wash pipe 61. The wash pipe extends further and is sized in diameter and length to fit ovver the fish. The wash pipe 61 telescopes over the stuck fish. As the wash pipe is advanced and washing continues to remove the material which sticks the fish, by means of rotation, washing and advancing the wash pipe can fully telescope over the fish until the threaded pin engages the upper end of the stuck fish. When advancement stops, the wash pipe is then rotated by rotating the drill string from the surface, thereby threading the pin 60 to the exposed upper end of the fish. Since the pin 60 matches in size and thread configuration with the box of the exposed fish at the upper end the two can be threaded to have quick retrieval.
Important details of construction on the interior of the means 50 should be noted. The sub 59 has an internal shoulder 62 which limits the lower end of travel of the sleeve 52. A ring 63 positioned on the interior of the apparatus 50 supports a set of collet fingers 64. The collet fingers extend upwardly parallel to the sleeve 52. The sleeve 52 has an external shoulder 65 which, in the up position of FIG. 6, is remote from the collet fingers 64. The exterior surface is slightly enlarged, having a tapered face 66 which abuts the collet fingers in the position of FIG. 6. This tapered area enables the collet fingers to deflect, thereby enabling the collet fingers to ride along the exterior of the sleeve 52 until sufficient travel has occurred (compare FIG. 7 with FIG. 6) at which point latching occurs. The collet fingers have sufficient spring force to clamp the telescoping sleeve in place until pump pressure is applied. The region around the collet fingers is isolated by an internal sleeve 67 which is sized to fit in that area, and is suitable pressure relief hole 68 opens into the sleeve. This permits pressure equalization so that the sleeve is not operating against a pressure build-up on downward movement.
The apparatus shown in FIGS. 6 and 7 functions in the same manner as does the embodiment 15 previously described. The primary difference however is the ability to thread the pin 60 into the stuck fish. During a washover operation, this is advantageous presuming the fish is known to have an exposed box, and the thread configuration and size of the box are known. In instances where this information is verified, the embodiment 50 can then be used to retrieve the stuck fish. Of course, the wash pipe below the pin 60 telescopes over the fish.
Perhaps an important factor to add in describing the operation of a washover fish retrieval utilizing the present apparatus is that the incorporation of this apparatus between the drill pipe and the wash pipe enables improved speed in a close tolerance situation. As will be understood, when the fish enters the wash pipe, plugging the wash pipe causes drilling fluid to fill the drill string to slow fluid flow. This fluid back flow along the drill string (being lowered into the borehole), interferes with rig floor procedures. The present invention thus provides an apparatus and method whereby fluid is normally transferred by the mud pumps at the surface into the drill sting and wash pipe as the wash pipe is telescoped over the fish. Moreover, the flow restriction is responsive to pump pressure close the valve of this apparatus, thereby directing fluid flow down through the wash pipe. During wash pipe insertion with no mud pumping, the valve is left open to prevent upward mud flow to the well head along the drill string; the mud level is equalized between the drill string and annular space by flow through the bypass.
While the foregoing is directed to the preferred embodiment, the scope is determined by the claims which follow.
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In a drill string connected to a wash pipe for retrieval of a fish in a well borehole, an apparatus comprising a connected tubular member therebetween having an internal movable sleeve. The sleeve is located close over a set of bypass ports to the exterior. The ports are selectively opened or closed; when closed, the fluid flow is directed to the fish in the wash pipe. A method of washing is set forth including the steps of controlling fluid flow so that, during running in of the wash pipe over the fish, fluid is bypassed. The bypassing occurs during the fish engagement improving speed of running in up to the time the wash pipe telescopes significantly over the fish.
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BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to a device for creating a notch in a waveform supplied by an alternating power source to a load and more particularly to a load comprising an inductive ballast for a fluorescent light to provide for the dimming thereof.
2. Reference to Other Applications
Two other patent applications filed in the name of the present inventors and assigned to the present assignee, entitled "Power Control For Inductive Loads" and "Time Delay Initialization Circuit," respectively, have been filed on even date herewith and disclose and claim circuits useful in cooperation with the present invention.
3. Description of the Prior Art.
In a co-pending application Ser. No. 898,569, filed Aug. 21, 1986, in the name of L. S. Atherton, R. A. Black, Jr., and A. D. Kompelien, and assigned to the assignee of the present invention, a circuit is described for use with a fluorescent light system to accomplish the dimming thereof by creating a "notch" in the waveform supplied by an alternating power source. The position and width of the "notch" are selected so as to reduce the power supplied to the fluorescent light ballast and thereby accomplish dimming thereof.
In this co-pending application, a pair of power diodes are connected with their cathodes connected to the power source and the load, respectively, and with their anodes connected together to a common node. A pair of unidirectional switches such as "gate turn-off" thyristors (GTO's) are also connected between the power source and the load. A first GTO is connected between the source and the node so as to conduct current from the source to the node during positive half cycles of the alternating supply providing that the GTO is "on". The second GTO is connected between the load and the node so as to conduct current from the load to the node during negative half cycles of the supply providing the GTO is "on". The GTO's are turned "on" during the majority of a cycle from the power source by a control signal being a positive signal applied to the control input or gate thereof from a control circuit. Accordingly, at the beginning of a positive half cycle, current flows from the power source through the first unidirectional switch to the node and from the node through the first power diode to the load. Likewise on the beginning of a negative half cycle, current flows from the load through the second unidirectional switch to the node and from the node through the first power diode to the source.
When it is desired to cut a "notch" in this waveform, the signal to the control electrodes or gates of the unidirectional switches are made negative so that the GTO's turn "off" and current no longer flows in the above-described path, and the load receives no current.
Since GTO's cannot be turned back "on" without consuming considerable switching power, the previous circuit also included a pair of silicon controlled rectifiers (SCR's) connected between the source and the node and one between the node and the load. When turned "on" by a control signal at the gate of each SCR, they conduct current in the same manner as the GTO's, i.e. from the source or the load to the node and then through the power diodes. Accordingly, at the end of the "notch" the first SCR is actuated by a control signal so that current could flow through the SCR to the node and through the power diode to the load for the remaining portion of the positive cycle. At the zero crossover, the silicon-controlled rectifier is automatically turned "off", but by this time the appropriate GTO is turned back "on" and current now flows through the switch and the power diode until the next "notch". At the end of the "notch" in the negative half cycle, the second SCR is turned "on" and current flows from the load through the SCR to the node and then from the node through the power diode to the source for the rest of the half cycle. "Notches" are preferably cut in both the positive and negative half cycles because otherwise a DC bias signal is created which causes undesirable flickering in the fluorescent lamp.
One problem associated with the above-described circuit is that after the notch has been created, the silicon-controlled rectifiers continue to conduct current for the remaining portion of the half cycle, and all of this current flows through the power diodes which consume a large amount of power and produce excessive heat.
SUMMARY OF THE INVENTION
The present invention overcomes this problem by connecting the silicon-controlled rectifiers between the input and the output so that when they are "on", current flows therethrough but not through the power diodes and, accordingly, the power diodes conduct current only during those times when the unidirectional switches are "on", which is only for a small portion of the cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic diagram of the present invention; and
FIG. 2 shows the load voltage waveform generated by the circuit of FIG. 1 and the various control signals utilized to turn the unidirectional switches "on" and "off".
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an input terminal 12 is shown for connection to an alternating current source 13 and, similarly, an output terminal 14 is shown for connection to an inductive load 16 shown in dash lines, the other end of which is connected to AC source 13 return at terminal 18.
A high impedance varistor 20 is connected between the input terminal 12 and a terminal 22 and operates to suppress large voltage transients occurring in the AC power source. A "snubber" circuit 23 is also shown connected between input terminal 12 and terminal 22 in parallel with varistor 20 and comprises a well known combination of resistors, capacitors and diodes for suppressing large voltage swings which are relatively rapid in nature. An inductive choke filter 24 is connected from terminal 22 to the load terminal 14.
A first unidirectional switch in the form of a GTO 30 is shown in FIG. 1 having its anode connected to the input terminal 12, having a cathode connected to a common node conductor 32 and having its gate connected to an input terminal 34 to which a first control voltage, E 1 , is supplied with respect to node 32 from circuitry similar to that shown in the above-mentioned co-pending application.
A second unidirectional switch in the form of a GTO 40 is shown having an anode connected to the terminal 22, having a cathode connected to the common node 32 and having its gate connected to an input terminal 44 to which a second control voltage, E 2 , is supplied from circuitry similar to that shown in the above-mentioned co-pending application. The waveforms for voltages E 1 and E 2 will be explained in connection with FIG. 2 below.
When a positive voltage appears at terminal 34, GTO 30 will be turned "on" so that current can flow from the AC source at terminal 12 through GTO 30 to the common node 32 whenever the input source is in a positive half cycle. Similarly, whenever the positive voltage appears at terminal 44, GTO 40 will be turned "on" so that current can flow from load 16 through terminal 22 and through GTO 40 to common node 32 whenever the input source is in a negative half cycle.
A pair of power diodes 50 and 52 are shown with their anodes connected together to the common node conductor 32 and with their cathodes connected to terminal 12 and terminal 22, respectively. It is seen that when GTO 30 is in an "on" condition, current can flow from terminal 12 through GTO 30, common node 32, power diode 52, and terminal 22 to the load 16 during positive half cycles of the source, and during negative half cycles of the source with GTO 40 in an "on" condition, current can flow from the load 16 to terminal 22, GTO 40, common node conductor 32 and power diode 50 to the terminal 12. It is seen that if positive signals were to exist at terminals 34 and 44 at all times, the load 16 would receive alternating current from the source at all times. This is the situation as it might exist if no dimming of the fluorescent light was required.
When dimming of the light is required, a "notch" is cut into the AC signal waveform as described in the above co-pending application. In the present application, this notch is cut by first causing the GTO's 30 and 40 to be turned "off" at a desired place in the alternating cycle and for a predetermined length of time. This is preferably accomplished by introducing a negative signal at the gate of the GTO's 30 and 40 at the appropriate time to begin a "notch". The negative signal will be produced by circuitry similar to that in the above-described co-pending application, at terminals 34 and 44, respectively, in a manner that will be described hereinafter in connection with FIG. 2.
During the time that GTO's 30 and 40 are in an "off" condition, no current flows to the load 16 and a notch is cut. When it is desired to resume current flow to the load 16, it is preferable not to use the GTO's 30 and 40, as explained above, since to do so would use a significant amount of switching power and conduction losses at that position on the waveform. SCR's have considerably lower conduction losses and, accordingly in FIG. 1, a pair of silicon-controlled rectifiers 60 and 62 are shown connected across the terminals 12 and 22 and poled for current flow in opposite directions. More specifically, the anode of SCR 62 is connected to input terminal 12 and the cathode thereof is connected to terminal 22, while the anode of SCR 60 is connected to terminal 22 and the cathode thereof is connected to input terminal 12. When a control signal appears at the gate terminal of SCR 62, it will be turned "on" and current will flow from terminal 12 through SCR 62 to terminal 22 and to load 16 during positive half cycles of the source. Likewise, when a control signal appears at the gate terminal of SCR 60, it will be turned "on" and current will flow from the load 16 through terminal 22 and through SCR 60 to input terminal 12 during negative half cycles. Unfortunately, SCR's do not have the ability to turn "off" again once they have been turned "on", and they will remain "on" until the input voltage passes through a zero crossover, at which time they will automatically turn "off".
To turn SCR's 60 and 62 to "on" conditions at the end of a notch, a third control signal identified as E 3 is applied with respect to node 32 to an input terminal 65 so as to present a positive signal on a conductor 68 to a terminal 70. The positive signal at terminal 70 is passed through a resistor 72 to the gate terminal of a third unidirectional switch 80 which may also be an GTO. GTO 80 has its anode connected to one terminal of a resistor 81 and its cathode connected by a line 82 to common node 32. A noise suppression circuit comprising resistor 83 and capacitor 84, the other terminal of which is connected to the resistor 72.
The other terminal of resistor 81 is connected to 1) the cathode of a diode 86 whose anode is connected to the terminal 22, and to 2) the cathode of a diode 88 whose anode is connected to the terminal 12. Terminal 70 is also connected through a resistor 90 to the anodes of a pair of diodes 92 and 94. The cathode of diode 94 is connected to the control terminal or gate of SCR 62, while the cathode of diode 92 is connected to the control terminal or gate of SCR 60. A noise suppression circuit comprising resistor 95 and a capacitor 96 are shown connected between the cathode of diode 94 and terminal 22, and a noise suppression circuit comprising resistor 97 and capacitor 98 are shown connected between the cathode of diode 92 and input terminal 12.
A positive signal at terminal 65 will operate to turn GTO 80 to an "on" condition, thereby establishing a path during positive half cycles from the terminal 12 through diode 88, resistor 81, GTO 80, and via line 82 to common node 32 and from there down through diode 52 to terminal 22. The signal at terminal 65 also turns SCR 62 "on" through resistor 90 and diode 94. Since common node 32 is "floating" relative to the anode and cathode of SCR 62, the circuit including GTO 80 is necessary to establish a reference so that SCR 62 will receive a definite positive signal at its gate and thereby assure that it is turned "on" when terminal 65 goes positive. In similar fashion, during negative half cycles a positive signal at terminal 65 will turn GTO 80 "on", thereby establishing a circuit from the load 16 through diode 86, resistor 81, GTO 80, and common node 32 up through diode 50 to terminal 12. The signal at terminal 65 also turns SCR 60 "on" through resistor 90 and diode 92. This establishes a path from terminal 65 through resistor 90 and diode 92 to the gate of SCR 60, thereby turning it "on". Again, since node 32 is "floating" relative to SCR 60, the circuit including GTO 80 is necessary to establish a positive signal at the gate of SCR 60 to enable it to be sure to turn "on" when a positive signal appears at terminal 65.
Thus, during positive half cycles, when SCR 62 is "on", a signal from the AC source passes through input terminal 12, SCR 62 to terminal 22 and to load 16, thereby bypassing diode 52 and saving power in a desirable fashion. Likewise, during negative half cycles when SCR 60 is "on", a signal from load 16 passes through terminal 22, SCR 60 to terminal 12, thereby bypassing power diode 50 and saving power in a desirable fashion.
Referring now to FIG. 2, the timing arrangement to create the various operations described in connection with the circuit of FIG. 1 is shown. In FIG. 2, the upper curve 100 represents the alternating current voltage source supply signal waveform into which a pair of notches 102 and 104 are shown to have been cut. At a beginning time t 0 , waveform 100 is shown to be moving out of a "zero crossing" position, and as explained above, at this time a signal at terminal 34 identified as E 1 is positive. Accordingly, current may flow from terminal 12 through GTO 30 to node 32 and through power diode 52 to the load 16. The E 2 signal at terminal 44 is also shown to be positive, but GTO 40 cannot conduct since it is reverse biased. The E 2 signal is seen to change to a negative signal at time t 1 to thereby turn GTO 40 to an "off" condition. At time t 2 , when it is desired to produce a "notch", the E 1 signal at terminal 34 becomes negative, and accordingly the signal from terminal 12 to load 16 is cut off. This continues for however long the negative signal at terminal 34 continues, but at time t 3 when it is desired that the notch terminate and that power be again supplied to the load, the E 3 signal at terminal 65 becomes positive which causes GTO 80 to conduct, thereby turning "on" SCR 62. Accordingly, from time t 3 until the next zero crossing at point 105, the signal from AC source 13 will pass from terminal 12 through SCR 62 to the load 16. Shortly after turning SCR 62 to an "on" condition, the signal at terminal 65 goes negative at time t 4 but SCR 62 will remain "on" until the zero crossing 105.
At time t 5 , shortly before the zero crossing 105 occurs, a positive signal E 1 and E 2 , at terminals 34 and 44, respectively, are again produced, thereby turning GTO's 30 and 40 to an "on" condition. The turning "on" of GTO's 30 and 40 is now at a low point in the AC voltage waveform and less power is dissipated in the switch than would be the case if they had been turned "on" earlier. Accordingly, when SCR 62 goes "off" at time t 6 , GTO 40 is now "on" so that current can flow from load 16 through terminal 22, GTO 40, and power diode 50 to input terminal 12. GTO 30 will not conduct since it is now reverse biased. This condition continues from time t 6 through a time t 7 when the E 1 signal appearing at terminal 34 goes negative to a time t 8 when the E 2 signal at terminal 44 goes negative. With the negative signal at terminal 44, GTO 40 is turned "off" and during the time t 8 to t 9 , no current flows from the load 16 so the "notch" 104 of FIG. 2 is carried. At time t 9 , however, another positive signal E 3 at terminal 65 will turn GTO 80 back "on" and thereby turn SCR 60 to an "on" condition. SCR 60 will then conduct current from load 16 through terminal 22, SCR 60 to input terminal 12 during the remainder of the negative half cycle to point 108. At time t 10 , the signal at terminal 65 disappears and GTO 80 goes to an "off" condition. SCR 60 will, however, continue conducting until the next zero crossover. At time t 11 shortly before the zero crossover at time t 12 , positive signals E 1 and E 2 at terminals 34 and 44 will turn GTO's 30 and 40 back on to an "on" condition so that the cycle will then repeat.
It is therefore seen that we have supplied a circuit for creating notches 102 and 104 with a minimum use of power dissipating diodes 50 and 52, thereby conserving power.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A circuit for cutting a "notch" in an alternating current supply waveform with the minimization of dissipated power comprising a pair of GTO's so poled to conduct current therethrough and also through a pair of power consuming diodes when the switches are "on" during alternate half cycles, the switches being turned "off" at the start of the "notches", and the current is resumed thereafter by a pair of oppositely poled SCR's which are turned "on" and which bypass power diodes so as to conserve power.
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TECHNICAL FIELD
The present invention relates to a transmission device using differential lines, and more particularly, to a novel circuit configuration for impedance match.
BACKGROUND ART
With the recent advances in performance of information processing systems, gigabit-per-second (Gbps) class serial signaling using a differential signal has been widespread. Such a higher-speed signal, however, leads to a noticeable waveform deterioration due to impedance mismatch (discontinuous structure).
Most of the high-speed serial transmission standards therefore require that reflection characteristics fall below a prescribed value in a wide frequency range.
In the case of a transmission device using differential lines, on the other hand, it is known that a parasitic inductance may be generated in a package or a module because wire bonding is used to connect a mounted chip to board wiring.
It is also known that a parasitic capacitance may be generated between the differential lines because an in-phase signal and an inverted-phase signal are often made in close proximity to each other in order to increase the signal density in a bump of a chip, a solder ball of a package, and a differential through hole in a PCB board.
As the signal frequency band becomes higher, the impedance mismatch due to those parasitic components becomes more noticeable to deteriorate the reflection characteristics. It has therefore become more difficult to satisfy a reflection prescribed value of the standards, which is one major problem.
In view of the above, the technology for achieving impedance match by a capacitance circuit and the technology of using an input/output terminal of an IC as an impedance transformer have hitherto been proposed as the countermeasure for the problem (see, for example, Patent Literature 1 and Patent Literature 2).
CITATION LIST
Patent Literature
[PTL 1] JP 05-37209 A
[PTL 2] JP 2010-206084 A
SUMMARY OF INVENTION
Technical Problem
The conventional transmission device has the following problem. According to the technologies described in Patent Literature 1 and Patent Literature 2, the technology for achieving impedance match and the design method therefor are originally derived from the technology for single-ended transmission, not assuming differential transmission. When applied to a differential transmission system, the conventional transmission device has been designed similarly to a general single-ended transmission system while imposing the symmetry condition on differential signals so that mode conversion may be prevented. An efficient technology cannot therefore be established for the differential transmission system.
The present invention has been made for solving the above-mentioned problem, and it is an object thereof to obtain a transmission device that establishes efficient match with an impedance mismatch section of a differential transmission system.
Solution to Problem
A transmission device according to one embodiment of the present invention includes: a differential driver; a differential receiver; a differential line that connects between the differential driver and the differential receiver, the differential line including in-phase signal wiring and inverted-phase signal wiring; a first delay increasing structure interposed in the differential line at an upstream of an impedance mismatch section; and a second delay increasing structure interposed at a downstream of the impedance mismatch section. The first delay increasing structure is interposed only in one of the in-phase signal wiring and the inverted-phase signal wiring, and the second delay increasing structure is interposed only in another of the in-phase signal wiring and the inverted-phase signal wiring.
Advantageous Effects of Invention
According to one embodiment of the present invention, the transmission characteristics can be improved and the reflection characteristics can be reduced in the impedance mismatch section on the differential lines.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram illustrating a transmission device according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating an impedance mismatch section of FIG. 1 in the form of an equivalent circuit.
FIG. 3 is a block diagram when a delay increasing structure of FIG. 1 is constructed by a transmission line.
FIG. 4 is a block diagram when the delay increasing structure of FIG. 1 is constructed by a capacitor element.
FIG. 5 is a block diagram when the delay increasing structure of FIG. 1 is constructed by an inductor element.
FIG. 6 is an explanatory graph showing a differential reflection reducing effect according to the first embodiment of the present invention in the form of simulation results in the configuration example of FIG. 3 .
FIG. 7 is an explanatory graph showing common reflection characteristics according to the first embodiment of the present invention in the form of simulation results in the configuration example of FIG. 3 .
FIG. 8 is an explanatory graph showing a differential transmission increasing effect according to the first embodiment of the present invention in the form of simulation results in the configuration example of FIG. 3 .
FIG. 9 is a block diagram illustrating a transmission device according to a second embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
First Embodiment
FIG. 1 is a block diagram illustrating a transmission device according to a first embodiment of the present invention, schematically illustrating a circuit when a communication device is constructed.
In FIG. 1 , the basic configuration of the transmission device (communication device) includes a differential driver 1 and a differential receiver 2 .
The differential driver 1 and the differential receiver 2 are connected to each other by differential lines formed of in-phase signal wiring L 1 and inverted-phase signal wiring L 2 (two pieces of wiring), and differential signals are transmitted from the differential driver 1 toward the differential receiver 2 .
An impedance mismatch section 3 is interposed in the middle of the differential lines between the differential driver 1 and the differential receiver 2 .
Examples of the impedance mismatch section 3 include a wire bond in an IC chip, a bump of a chip, a solder ball of a package, a through hole in a PCB board, and a connector.
At the upstream of the impedance mismatch section 3 on the differential lines, a first delay increasing structure 4 a (hereinafter sometimes referred to simply as “delay increasing structure 4 a ”) for increasing a delay of only one of the in-phase signal wiring L 1 and the inverted-phase signal wiring L 2 (in this case, the inverted-phase signal wiring L 2 ) is interposed.
At the downstream of the impedance mismatch section 3 , a second delay increasing structure 4 b (hereinafter sometimes referred to simply as “delay increasing structure 4 b ”) is interposed in a line having the opposite polarity to the line for the upstream delay increasing structure (in this case, the in-phase signal wiring L 1 ).
Next, a description is given of the circuit operation according to the first embodiment of the present invention illustrated in FIG. 1 .
First, the differential signals output from the differential driver 1 are transmitted through the differential lines formed of the in-phase signal wiring L 1 and the inverted-phase signal wiring L 2 (two pieces of wiring) and are directed toward the impedance mismatch section 3 .
In this case, because the delay increasing structure 4 a is interposed at the upstream of the impedance mismatch section 3 , a part of the differential signals are converted into common-mode signals and thereafter the signals enter the impedance mismatch section 3 .
At this time, reflection occurs in the impedance mismatch section 3 because of the impedance mismatch, but a part of the reflected wave becomes a reflection component for the differential mode and another part becomes a reflection component for the common mode due to the delay increasing structure 4 a.
In this manner, the reflected wave generated by the impedance mismatch section 3 is dispersed into the two modes, and hence the reflection component for the differential mode is reduced as compared to the case where the signals are all reflected as the differential mode.
Most of the standards of high-speed serial signaling define only the differential-mode reflection component with respect to a differential-mode signal input but do not define the common-mode reflection component with respect to the differential-mode signal input. Consequently, the effect that the standards are more easily satisfied can be obtained owing to the effect of reducing the differential-mode reflection component with respect to the differential-mode signal input.
Now consider the case where the impedance mismatch section 3 is undesired coupling between the differential lines.
A description is now given of the case where the undesired coupling of the impedance mismatch section 3 is a differential capacitance 3 a as exemplified by a circuit configuration example of FIG. 2 .
FIG. 2 is a block diagram illustrating the impedance mismatch section 3 of FIG. 1 in the form of an equivalent circuit. The illustrated equivalent circuit corresponds to the case where the differential capacitance 3 a (parasitic capacitance) is generated between the differential lines when an in-phase signal and an inverted-phase signal are made in proximity to each other in order to increase the signal density in a bump of a chip, a solder ball of a package, a differential through hole in a PCB board, or the like.
In FIG. 2 , the delay increasing structure 4 a is interposed at the upstream of the impedance mismatch section 3 (inverted-phase signal wiring L 2 ), and hence at least a part of the signals are converted into the common mode and enter the impedance mismatch section 3 .
When the delay increasing structure 4 a is equal to the half-wave length of the signals, the signals are all converted into the common mode and enter the impedance mismatch section 3 .
In this case, the common-mode signal is a mode in which the two pieces of wiring L 1 and L 2 constructing the differential lines change with the same potential, and hence the differential capacitance 3 a is regarded as being absent equivalently. In other words, no reflection caused by the parasitic capacitance occurs and thus the transmission increases.
The signals that have passed through the impedance mismatch section 3 are converted into the differential mode again by the delay increasing structure 4 b , which is interposed at the downstream of the impedance mismatch section 3 on the line having the opposite polarity to the line for the upstream delay increasing structure (in-phase signal wiring L 1 ), and are input to the differential receiver 2 .
Note that, although the general delay increasing structures 4 a and 4 b have been described with reference to FIGS. 1 and 2 , for example, the delay increasing structures may be constructed by transmission lines 5 a and 5 b as illustrated in FIG. 3 , may be constructed by capacitor elements 6 a and 6 b connected to a GND 10 as illustrated in FIG. 4 , and may be constructed by series inductor elements 7 a and 7 b as illustrated in FIG. 5 .
It should be understood that FIGS. 3 to 5 may be combined, and, for example, the present invention is applicable also to a ladder circuit in which the plurality of capacitor elements 6 a and 6 b ( FIG. 4 ) connected to the GND 10 and the plurality of series inductor elements 7 a and 7 b ( FIG. 5 ) are arranged alternately.
FIGS. 6 , 7 , and 8 are explanatory graphs showing the effects obtained by the first embodiment of the present invention, each showing the simulation result in the configuration example of FIG. 3 (the case where the delay increasing structures 4 a and 4 b are the transmission lines 5 a and 5 b ).
FIG. 6 shows frequency characteristics when the signals are reflected in the differential mode, in which the horizontal axis represents the frequency (GHz) and the vertical axis represents the differential reflectance (dB).
FIG. 7 shows frequency characteristics when the signals are reflected in the common mode, in which the horizontal axis represents the frequency (GHz) and the vertical axis represents the common reflectance (dB).
FIG. 8 shows frequency characteristics when the signals are transmitted in the differential mode, in which the horizontal axis represents the frequency (GHz) and the vertical axis represents the differential transmission rate (dB).
In FIG. 6 , it can be confirmed that the reflectance in the differential mode is suppressed by adding the delay increasing structure 4 a (transmission line 5 a ) at the upstream as compared to the case where the delay increasing structure is not provided.
In FIG. 7 , on the other hand, it can be confirmed that the reflectance in the common mode is increased by adding the delay increasing structure 4 a (transmission line 5 a ) at the upstream as compared to the case where the delay increasing structure is not provided (−∞ dB). In other words, by converting the differential-mode signals temporarily into the common-mode signals, an influence reducing effect for the undesired coupling between the differential wirings can be obtained. Note that, even if the reflection in the common mode increases, the value thereof does not particularly deviate from the standards in most cases.
In FIG. 8 , it can also be confirmed that the transmission characteristics in the differential mode become larger by adding the delay increasing structure 4 b (transmission line 5 b ) at the downstream so that the signals are returned to the differential mode from the common mode as compared to the case where the delay increasing structure is not provided.
Note that, although the delay increasing structure 4 a is interposed only in the inverted-phase signal wiring L 2 at the upstream of the impedance mismatch section 3 and the delay increasing structure 4 b is interposed only in the in-phase signal wiring L 1 at the downstream of the impedance mismatch section 3 in FIGS. 1 to 5 , the delay increasing structure 4 a may be interposed only in the in-phase signal wiring L 1 at the upstream of the impedance mismatch section 3 and the delay increasing structure 4 b may be interposed only in the inverted-phase signal wiring L 2 at the downstream of the impedance mismatch section 3 conversely.
As described above, the transmission device according to the first embodiment of the present invention ( FIGS. 1 to 8 ) includes the differential driver 1 , the differential receiver 2 , the differential line that connects between the differential driver 1 and the differential receiver 2 and includes the in-phase signal wiring L 1 and the inverted-phase signal wiring L 2 , the first delay increasing structure 4 a interposed in the differential line at the upstream of the impedance mismatch section 3 , and the second delay increasing structure 4 b interposed at the downstream of the impedance mismatch section 3 .
The first delay increasing structure 4 a is interposed only in one of the in-phase signal wiring L 1 and the inverted-phase signal wiring L 2 (for example, the inverted-phase signal wiring L 2 ), and the second delay increasing structure 4 b is interposed only in the other of the in-phase signal wiring L 1 and the inverted-phase signal wiring L 2 (for example, the in-phase signal wiring L 1 ).
The first and second delay increasing structures 4 a and 4 b respectively include the transmission lines 5 a and 5 b ( FIG. 3 ), the capacitor elements 6 a and 6 b ( FIG. 4 ), or the inductor elements 7 a and 7 b ( FIG. 5 ), and can be constructed by a ladder circuit formed of the capacitor elements 6 a and 6 b and the inductor elements 7 a and 7 b.
In this manner, at the upstream of the impedance mismatch section 3 , the reflection reducing effect ( FIG. 6 ) in the differential mode owing to the dispersion of the reflected wave into the differential mode and the common mode and the influence reducing effect ( FIG. 7 ) for undesired coupling between differential wirings (differential capacitance 3 a ) owing to temporary conversion of the differential-mode signal into the common mode can be obtained as the effects obtained by interposing the delay increasing structure 4 a.
Further, at the downstream of the impedance mismatch section 3 , the transmission increasing effect ( FIG. 8 ) for the differential signal can be obtained as the effect obtained by interposing the delay increasing structure 4 b.
Further, the delay increasing structures 4 a and 4 b are constructed by, for example, the transmission lines 5 a and 5 b ( FIG. 3 ) or the like, and can therefore be realized at low cost.
Now, a specific description is given of the first effect (improvement on transmission characteristics and reflection characteristics).
When it is assumed that the impedance mismatch section 3 is, for example, the differential capacitance 3 a ( FIG. 2 ), a large reflection generally occurs with respect to a differential input at high frequency, but a part of the incident differential signals are converted into the common mode by the delay increasing structure 4 a interposed in one wiring (inverted-phase signal wiring L 2 ) at the upstream of the impedance mismatch section 3 (discontinuous structure) on the differential line.
For the common-mode signals, two differential signals have the same potential, and hence the differential capacitance 3 a is regarded as being absent equivalently. Thus, no reflection occurs due to the parasitic capacitance and the transmission increases. The signals are further converted again from the common mode into the differential mode by the delay increasing structure 4 b interposed at the downstream of the impedance mismatch section 3 .
As a result, the effects that the transmission characteristics are improved and the reflection characteristics are reduced in the impedance mismatch section 3 on the differential lines can be obtained.
Now, a specific description is given of the second effect (satisfaction of the standards of high-speed serial signaling).
According to the first embodiment of the present invention, the delay increasing structure 4 a (asymmetric structure) is interposed at the upstream of the impedance mismatch section 3 so that the differential mode and the common mode are coupled to each other, and hence, when the differential-mode enters, reflection involving the mode conversion occurs so that a part thereof is reflected as the differential mode and another part is reflected as the common mode.
In this manner, the reflected wave of the impedance mismatch section 3 is dispersed into the two modes, and hence the differential-mode reflection component with respect to the differential-mode signal input is reduced.
Most of the standards of high-speed serial signaling define only the differential-mode reflection component with respect to a differential-mode signal input but do not define the common-mode reflection component with respect to the differential-mode signal input. Consequently, the effect that the standards are more easily satisfied can be obtained owing to the effect of reducing the differential-mode reflection component with respect to the differential-mode signal input.
Owing to the first and second effects described above, the transmission characteristics are improved and the reflection characteristics are reduced with respect to the differential signals.
Second Embodiment
Note that, although the first embodiment ( FIGS. 1 to 5 ) improves the reflection characteristics by interposing the delay increasing structure 4 a on the upstream side of the impedance mismatch section 3 and improves the transmission characteristics of the differential signals by interposing the delay increasing structure 4 b also on the downstream side, only the delay increasing structure 4 a on the upstream side of the impedance mismatch section 3 may be interposed to improve only the reflection characteristics as illustrated in FIG. 9 .
FIG. 9 is a block diagram illustrating a transmission device according to a second embodiment of the present invention, schematically illustrating a circuit when a communication device is constructed similarly to the above ( FIG. 1 ).
In FIG. 9 , the same components as those described above (see FIG. 1 ) are denoted by the same reference symbols as those used above to omit the detailed descriptions thereof.
This case is different from the above in that only the delay increasing structure 4 a is interposed on the upstream side of the impedance mismatch section 3 and that the delay increasing structure 4 b ( FIG. 1 ) on the downstream side is removed.
Also in this case, the delay increasing structure 4 a is constructed by any one of the transmission line 5 a ( FIG. 3 ), the capacitor element 6 a ( FIG. 4 ), and the inductor element 7 a ( FIG. 5 ).
The circuit configuration of FIG. 9 can obtain the reflection reducing effect ( FIG. 6 ) in the differential mode owing to the dispersion of the reflected wave into the differential mode and the common mode from among the effects according to the first embodiment.
Because the delay increasing structure 4 b at the downstream is not present, there is another advantage that this circuit configuration is applicable even when the impedance mismatch section 3 is located immediately close to the differential receiver 2 .
Note that, although the delay increasing structure 4 a is interposed only in the inverted-phase signal wiring L 2 at the upstream of the impedance mismatch section 3 in FIG. 9 , the delay increasing structure 4 a may be interposed only in the in-phase signal wiring L 1 .
REFERENCE SIGNS LIST
1 differential driver, 2 differential receiver, 3 impedance mismatch section, 3 a differential capacitance, 4 a , 4 b delay increasing structure, 5 a , 5 b transmission line, 6 a , 6 b capacitor element, 7 a , 7 b inductor element, 10 GND, L 1 in-phase signal wiring, L 2 inverted-phase signal wiring
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A transmission device that establishes efficient match with an impedance mismatch section of a differential transmission system. The transmission device includes: a differential driver; a differential receiver; a differential line that connects between the differential driver and the differential receiver, the differential line including in-phase signal wiring and inverted-phase signal wiring; a delay increasing structure interposed in the differential line at an upstream of the impedance mismatch section; and a delay increasing structure interposed at a downstream of the impedance mismatch section. The delay increasing structure is interposed only in one of the in-phase signal wiring and the inverted-phase signal wiring, and the delay increasing structure is interposed only in another of the in-phase signal wiring and the inverted-phase signal wiring.
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